Features of observation and experiment in medicine
Observation- a method of empirical knowledge that has the goal of collecting, accumulating and describing scientific facts. It supplies primary material for scientific research. Observation is a systematic, purposeful and planned study of reality. Observation uses various techniques such as comparison, measurement, etc. If ordinary observation gives us information about the qualitative characteristics of an object, then measurement gives us more accurate knowledge and characterizes the object in terms of quantity. Observation with the help of devices and technical means (microscope, telescope, X-ray machine, etc.) makes it possible to significantly expand the range of sensory perception. At the same time, observation as a method of cognition is limited; the researcher states only what is happening in objective reality, without interfering in the natural course of processes.
Until the 17th century, clinical observation was the only method of knowledge in medicine. K. Bernard calls this period of medicine observational, for the first time shows the limited nature of this method and becomes a pioneer of experimental medicine. Since the advent of the experimental approach to the study of diseases, medicine has become scientific.
In some professions (medicine, criminology, etc.), a sense of observation is very important. Features of observation in medicine are determined by its role and consequences. If at the observation level the doctor misses some symptoms or changes, then this will necessarily lead to errors in diagnosis and treatment.
Experiment(Latin experimentum - test, experience) - a means of cognition of objective reality through active influence on it by creating new conditions that correspond to the goals of the study or by changing the processes themselves in the required direction. An experiment is a research method when the researcher actively influences the subject, creating artificial conditions to identify certain properties or when the object itself is artificially reproduced. The experiment allows you to study a subject in pure conditions (when minor factors are excluded) and in extreme situations. If in real conditions (for example, during observation) we depend on the natural course of phenomena and processes, then in an experiment we have the opportunity to repeat them an unlimited number of times.
The development of modern science is impossible without the use of experiment. The experiment is used for educational purposes, to solve certain scientific problems, to test certain hypotheses and for educational purposes. In other words, they distinguish research, testing and demonstration experiments. According to the mode of action they are distinguished physical, chemical, biological, psychological, medical, social etc.
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experiments. Depending on the flow conditions, experiments are distinguished natural and laboratory. A laboratory experiment is carried out on material models (animals, plants, microorganisms, etc.) or mental, ideal ones (mathematical, informational, etc.).
In medicine, an experiment involves active intervention in the human body, which leads to a change in physiological or pathological processes from scientific or therapeutic purpose. In a narrow sense, a medical experiment is the application for the first time of certain methods of influencing human body for therapeutic or research purposes. But what is used for the first time is not always an experiment. Therefore, it is necessary to distinguish an experiment (which is carried out systematically and for the purpose of knowledge) from forced treatment tactics.
Features of observation and experiment in medicine - concept and types. Classification and features of the category "Peculiarities of observation and experiment in medicine" 2015, 2017-2018.
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Diagnostic examination methods or diagnostic technique
Diagnostic observation methods include medical observation and examination of the patient, as well as the development and application special methods studying morphological, biochemical and functional changes associated with the disease. Historically, the earliest diagnostic methods include the basic methods of medical examination - anamnesis, examination, palpation, percussion, auscultation.
There are 3 types of examination of the patient: a) questioning, b) examination, percussion, palpation, auscultation, that is, direct sensory examination and c) laboratory-instrumental examination. All three types of examination are both subjective and objective, but the questioning method is the most subjective. When conducting an examination of a patient, the doctor must be guided by a certain system and strictly adhere to it. This examination scheme is taught in medical institutes and, first of all, in the departments of propaedeutics.
Subjective examination.
The examination of the patient begins with listening to his complaints and questioning, which are the most ancient diagnostic techniques. The founders of Russian clinical medicine attached great diagnostic importance to the patient’s complaints, his story about the disease and life. M. Ya. Mudrov was the first in Russia to introduce routine questioning of patients and medical history. Despite its apparent simplicity and general availability, the questioning method is difficult and requires considerable skill and special training of the doctor. When collecting anamnesis, it is necessary to identify the sequence of development of certain symptoms, possible changes in their severity and nature as the pathological process unfolds. In the first days of the disease, complaints may be mild, but intensify in the future. According to B. S. Shklyar (1972), “...the patient’s complaints, his sensations are a reflection in his consciousness of the objective processes occurring in his body. The ability to unravel these objective processes behind the patient’s verbal complaints depends on the doctor’s knowledge and experience.”
However, patients’ complaints are often of purely functional origin. In some cases, due to increased emotionality, patients unintentionally distort their internal sensations, their complaints acquire an inadequate, distorted character, and have a purely individual expression. At the same time, there are complaints that are of a general nature, but inherent in certain diseases, for example, pain in the heart with radiation to the left arm during angina pectoris, etc. The main complaints are those that determine the underlying disease; they are usually the most constant and persistent , intensify as the disease progresses. M. S. Maslov (1948) emphasized that a correctly conducted analysis of the anamnesis and symptomatology of the disease is the alpha and omega of medical practice, and in the diagnosis of pyloric stenosis in infants, the anamnesis is of decisive importance. Anamnesis is also of great importance in the diagnosis of round peptic ulcer of the stomach and duodenal ulcer in children. M. S. Maslov believed that in a number of childhood diseases, anamnesis is everything, and an objective examination is only a small addition and the diagnosis is often ready by the time the anamnesis is completed. M. S. Maslov persistently emphasized that in pediatrics the diagnosis should be made primarily on the basis of anamnesis and such simple methods of objective examination as inspection, percussion, palpation, auscultation, while complex examination methods that clarify the diagnosis should be resorted to only then when the doctor has a certain idea about the disease.
When listening to complaints and questioning the patient, the doctor must not forget that the patient is not only an object, but also a subject, therefore, before proceeding with a detailed questioning, you should familiarize yourself with the patient’s personality, find out age, profession, previous diseases, lifestyle and living conditions, and etc., which will help to better understand the patient’s personality and the nature of the disease. The doctor must always remember that the patient is an individual. Unfortunately, this position is not emphasized enough to students at institutes, and attention to the patient’s personality should be constantly increased. Underestimation of personality comes from a misunderstanding of the role of the biological and social in a person. Only as a result integrated approach to the patient as an individual, one can avoid the extremes of both biologism and vulgar sociologism. The range of environmental influences on the human body is large, but it largely depends on the individual characteristics of the organism, its hereditary predisposition, state of reactivity, etc. Since man is a rational being, possessing higher nervous activity, questioning the patient is one of the methods of studying the psyche, finding out states of higher nervous activity, and the questioning itself should be classified as a specific examination method. I. P. Pavlov considered the questioning method an objective method for studying human mental activity.
Intellectual development Patients are different, so the doctor must, during the examination process, develop the most appropriate manner of communication for a given patient. It happens that some doctors are rude in conversation, others fall into a sugary-sweet tone (“darling”, “buddy”), and still others resort to a deliberately primitive, pseudo-democratic manner of talking with the patient. Bernard Shaw once remarked that there are 50 ways to say “yes” or “no,” but only one way to write them. The doctor must constantly monitor the tone of his conversation with the patient. A false tone does not encourage the patient to have an open conversation with the doctor. It should be remembered that during the questioning the patient, in turn, studies the doctor and seeks to find out the degree of his competence and reliability. Therefore, while listening sympathetically to the patient, the doctor must be able to find the golden mean of communication, lying between a strictly objective official manner of behavior and exaggerated sentimental concern. A good doctor is one with whom you can talk in any way: from a light, simple conversation to a deep, serious exchange of opinions. The word “doctor” comes from the old Russian word “vrat”, which means “to speak”, “to talk”. In the old days, a doctor had to be able to “charm” diseases. In diagnosis, an important role is played by direct impression, the impression of “first sight”.
A peculiarity of human thinking is that it is never isolated from other manifestations of the psyche and, above all, from emotions, therefore not all truths can be proven using only formal logical means (V. A. Postovit, 1985). Information processing in the brain is carried out using 2 programs - intellectual and emotional. Through close psychological contact with the patient, the doctor strives at the patient’s bedside to find out the most characteristic, most important things relating to both the individual and the disease itself. The philosopher Plato was surprised that artists, while creating good works, do not know how to explain their powers, hence the myth about the “shepherd intellect” of artists. In reality, apparently, we are talking about harmony in art, which is not yet accessible to systematic analysis.
Questioning is a difficult and complex method of examination, to master which you need to work on yourself a lot and in many ways. Unfortunately, some graduates of our medical universities do not know how to listen to patients with interest and attention. It is important to listen to the patient with a stethoscope, but it is even more important to be able to simply listen to him and calm him down. The reason for this
inability lies in the still weak practical preparedness of young doctors, in the insufficient practice of their communication with patients during their student years. Psychoneurologist M. Kabanov complained that during 6 years of study, medical university students study the human body for 8,000 hours, and the human soul (psychology) for only about 40 hours (“Pravda” dated 28-V-1988).
Currently, due to the technicalization of the diagnostic process and treatment, the principle of individual approach to the patient. At times, the doctor begins to forget that the patient is an individual and underestimates the patient’s psychology, but to treat means to a large extent to be able to control the patient’s personality. Therefore, the institute should maximally instill in the future doctor the holistic and personal direction of medicine, cultivated since the time of Hippocrates.
It has been noticed that the lower the doctor’s qualifications, the less he speaks with the patient. The anamnesis can be quite complete when full psychological contact is established between the doctor and the patient. Patients may tell different doctors differently about their illness. For example, women often talk differently about themselves and about their illness, depending on whether the doctor is a woman or a man. The more experienced the doctor, the more data he receives when questioning the patient.
The patient's complaints play a leading role in shaping the diagnostic direction of the doctor's thinking. The primary diagnostic “sorting” depends on the patient’s complaints. The patient outlines first of all those complaints that attracted his attention and seem to him to be the main ones, which, however, is not always the case and, in addition, many symptoms escape the attention of the patient or are even unknown to him. Therefore, the clarification of complaints should not be reduced to their passive listening, the doctor is obliged to actively question the patient and, thus, this examination process consists, as we have already mentioned, of two parts: the passive-natural story of the patient and the active-skilled, professional questioning of the doctor. Let us recall that S.P. Botkin pointed out that the collection of facts should be carried out with a certain guiding idea.
When conducting an active clarification of the patient’s complaints, the doctor should strive to maintain complete objectivity and in no case pose questions to the patient, the wording of which suggests a definite answer in advance. Physicians who are prone to biased diagnoses and seek to artificially bring the facts under their preconceived diagnosis often resort to posing such questions. In these cases, the doctor manifests an unhealthy desire to show off his supposed insight in front of the patient or others. There are also easily suggestible patients who seek the doctor’s favor and obsequiously assent to him. The diagnosis should not be biased.
In the 50s in Kiev medical institute an already middle-aged, experienced assistant professor therapist, prone to some boasting, was working. Once, together with his 6th year students, examining a sick, venerable Ukrainian peasant woman, and not finding “pregnant stripes” on the skin of her abdomen, he, not without boasting, told the students that the patient had no children and asked her to confirm this. The patient confirmed, but after a pause, during which the assistant professor looked triumphantly at the students, she added: “There were three sons, and all three of them were in Viyni.” The result was an embarrassment that many people learned about.
After clarifying the patient’s complaints, they proceed to the most important part - questioning and anamnesis. Anamnesis is the patient’s recollection, his story about the onset and development of the disease in the patient’s own understanding. This is a “history of illness.” But there is also a “life history” - this is the patient’s story about his life, about the diseases he has suffered.
G. A. Reinberg (1951) also distinguished “forgotten anamnesis” - active identification in the patient’s memory of long-past and already forgotten events and the so-called “lost anamnesis” - identification in past life the patient experiences events that he himself does not know about in essence. As an example of a “lost history,” G. A. Reinberg describes a patient in whom visceral syphilis was discovered based on the available indirect signs - a non-healing fracture of the legs, and the patient did not know about his syphilis disease. However, G. A. Reinberg’s proposals were not widespread. “Forgotten anamnesis” is essentially an anamnesis of life, and the identification of “lost anamnesis” is quite artificial.
The importance of anamnesis in diagnosis is difficult to overestimate, although it is not equivalent for various diseases. As G, A. Reinberg (1951) points out, at the end of the 19th and beginning of the 20th centuries there was a dispute between therapists in Moscow and St. Petersburg: the Moscow school attached the main importance in making a diagnosis to anamnesis, the St. Petersburg school to an objective examination. Life has shown that only a skillful combination of subjective and objective examination data makes it possible to most fully recognize the disease. Experienced doctors know that a good anamnesis is half the diagnosis, especially if the patient has sufficiently and accurately conveyed the symptoms and they are specific, and the doctor is dealing with a disease in which the clinical picture is dominated by subjective symptoms.
Taking an anamnesis, as mentioned earlier, consists of a relaxed story by the patient about the onset and development of the disease and a directed questioning of the doctor, during which he evaluates the essential and non-essential in the story, while simultaneously observing the neuropsychic state of the patient. That is, we emphasize once again that questioning is not a passive process of mechanically listening and recording information about the patient, but a systematic process organized by the doctor.
The method of collecting anamnesis was perfectly developed in the Moscow clinics of the founders of domestic therapy G. A. Zakharyin and A. A. Ostroumov. G. A. Zakharyin constantly emphasized the need to adhere to a strict scheme for examining patients and in his clinical lectures (1909) pointed out: “A novice doctor, if he has not mastered the method... asks randomly... gets carried away by the first impression... hopes quickly to solve the matter by asking the patient several questions related to this, but without exhausting the state of the whole organism with questioning... the only correct, although slower and more difficult, path is to observe the completeness and well-known once accepted order in the study.” G. A. Zakharyin brought the anamnesis method to virtuosity, but paid somewhat less attention to objective symptoms. In his opinion, anamnesis allows one to obtain a more accurate picture of the disease than the known physical methods of research.
There are various anamnesis schemes that are taught in medical institutes, but whatever schemes the doctor adheres to, it is necessary that they ensure sufficient completeness of the examination of patients and do not allow anything important for the diagnosis to be missed. Therefore, when collecting an anamnesis, one must not deviate from the questioning plan; the ability to hear a patient is not a simple wish - after all, sometimes we listen, but do not hear, we look, but do not see. Consistent questioning provides a huge amount of information, often replacing complex diagnostic tests, and sometimes determines the diagnosis. R. Hegglin (1965) believes that based on anamnesis, the diagnosis is established in more than 50% of cases, according to physical examination - in 30%, and according to laboratory data - in 20% of patients. V. X. Vasilenko (1985) pointed out that in almost half of the cases the anamnesis allows for a correct diagnosis. The famous English cardiologist P. D. White (1960) said that if the doctor cannot collect a good history, and the patient cannot tell it well, then both of them are in danger: the first - from the prescription, the second - from the use of unsuccessful treatment. P. D. White (1960) emphasized that the patient’s history often contains many keys to resolving issues of diagnosis and treatment, but often this part of the patient’s examination is most neglected by doctors. Haste and lack of systematic questioning are usually the reasons for such neglect. Taking a medical history requires more time than other types of examination, but the physician should not skimp on taking the history.
The accepted procedure for examining a patient, when a questioning is carried out first, and then an objective examination cannot, however, be absolute, because often, as certain symptoms are discovered, there is a need to return to the anamnesis, clarifying or supplementing its various aspects, examining and evaluating them. from new positions. According to N.V. Elshtein (1983), the main mistakes made by therapists when collecting anamnesis are the following: a) underestimation of characteristic complaints, lack of desire to find out the relationship of symptoms, time, frequency of their appearance, b) underestimation of the difference between the onset of the disease and the onset of its exacerbation , c) underestimation of epidemiological, “pharmaco-allergic” anamnesis, d) underestimation living conditions, family relationships, sexual life. The questioning method should be considered as a strictly objective and scientific method of examining a patient, with the help of which, as well as clarifying the nature of the patients’ complaints, the doctor forms an initial idea of the picture of the disease as a whole, forming a preliminary diagnosis.
Objective examination.
The diagnostic techniques of the great clinicians of the past, along with questioning and observation, included such simple physical methods as palpation, percussion, and auscultation. Hippocrates pointed out that judgments of disease arise through sight, touch, hearing, smell and taste. Hippocrates also made the first attempt to auscultate patients. Physical methods of examining patients have retained their importance to this day, despite the fact that they have already exhausted their potential for establishing new scientific facts. The development of science and medical technology has made it possible to strengthen simple physical examination methods and supplement them with new tools and devices, which has significantly increased the level of diagnosis.
But even now the main diagnostic method is the clinical method, the essence of which is a direct examination of the patient using the doctor’s senses and some simple devices that increase the resolution of the senses. The clinical method includes analysis of the patient’s complaints, anamnesis, examination, palpation, percussion, auscultation, and observation of the dynamics of the disease.
You cannot seriously talk about diagnosis if the doctor does not have sufficient knowledge of examination methods and is not confident in the reliability of his examination. If a doctor does not master the clinical method, then he cannot be considered a practical doctor. A doctor, like a musician, must be fluent in the technique of examining a patient.
Mastering the clinical method of examining a patient is not as simple as it seems at first glance - it requires a lot of work and years. Although physical methods (inspection, palpation, percussion, auscultation) are classified as the simplest methods, the term “simple methods” must be understood taking into account the fact that these methods are both simple and complex: simple - because they do not require complex equipment, but complex - because mastering them requires long and serious training. Physical methods sometimes provide more information than instrumental ones. Symptoms of the disease, identified using the clinical method, are the primary factual material on the basis of which the diagnosis is based. The first condition for the effective use of clinical research methods is technically correct mastery of them, the second is their strictly objective application, and the third is a complete examination of the patient “from head to toe” even when the diagnosis is supposedly clear at first glance. Even a young and inexperienced doctor who conscientiously, without haste, examined a patient, knows him better than a more experienced specialist who hastily examined him.
When starting an examination of a patient, the doctor must avoid biased opinions about the diagnosis; therefore, the examination itself is carried out first, and then familiarization with certificates, extracts and conclusions from other medical institutions. M. S. Maslov (1048) emphasized that basically the diagnosis should be made on the basis of anamnesis and simple examination methods: inspection, percussion, palpation and auscultation. Based on our many years of practical experience, we believe that after examining a patient using a clinical method, it is already possible to make a presumptive, and in some cases, a substantiated diagnosis. If the clinical method does not make it possible to make a diagnosis, then additional and more complex examination methods are resorted to. During a clinical examination of a patient, as noted by I. N. Osipov and P. V. Kopnin (1962), vision is most widely used, with the help of which the examination is carried out. Visual irritations have a very low threshold, which is why even a very small irritation can already cause visual perceptions, which, due to an insignificant difference threshold, enable the human eye to distinguish between an increase or decrease in light irritation by a very small amount.
Percussion and auscultation are based on auditory perceptions, palpation and partly direct percussion are based on touch, which also makes it possible to determine the humidity and temperature of the skin. The sense of smell can also have some significance in diagnosis, and ancient doctors even detected the presence of sugar in the urine of diabetes by taste. Most of the symptoms detected through vision, such as skin color, physique, gross changes in the skeleton, rashes on the skin and mucous membranes, facial expression, eye shine and many others belong to the category of reliable signs. It was not for nothing that the outstanding pediatrician N.F. Filatov sometimes sat silently at the child’s bedside for a long time, observing him. The second place in reliability, after symptoms detected visually, is occupied by symptoms detected by palpation using touch, especially when examining the lymphatic and musculoskeletal system, pulse, abdominal organs, etc. It should be noted that the tactile abilities of the fingers of different doctors are not the same, which depends both on innate characteristics and on acquired experience. Outstanding Russian clinicians V.P. Obraztsov, N.D. Strazhesko and others have done a lot to improve the palpation method. Percussion and auscultation data, based on auditory perceptions, have only relative accuracy, since we do not perceive many sounds. It is not for nothing that people say that it is better to see once than to hear a hundred times, and, probably, this saying does not sound as realistic anywhere as in the field of practical medicine. The human ear distinguishes sounds from 16 to 20,000 vibrations in 1 s, but it has maximum sensitivity to sounds with a vibration range from 1000 to 3000, while sensitivity to sounds with a vibration range of up to 1000 and over 3000 decreases sharply and the higher the sound, the it is perceived worse. The ability to distinguish the height and duration of a sound varies greatly individually, which depends on the age of people, the degree of their training, fatigue, and the development of the hearing organs, therefore percussion and auscultation often reveal only probable symptoms that are of relative importance, due to which they need to be approached more carefully than to symptoms obtained by inspection or palpation.
The human senses are not so perfect that they can be used to detect the manifestations of all pathological processes, therefore, during dynamic monitoring of the patient, it is necessary to conduct repeated studies.
The condition of many organs and systems of the patient is not amenable to direct research, therefore clinical medicine constantly strives to overcome the limitations and relativity of sensory perceptions. Medical perception also depends on the purpose of the examination, namely: a specialist, thanks to his experience and skill, fixed in the conscious and subconscious spheres, can see what others do not notice. But you can look and not understand, feel and not perceive - only thinking eyes are able to see. Without sensations, no knowledge is possible. The French clinician Trousseau called for constantly observing patients and remembering images of diseases.
The primary task of an objective examination is to identify the main set of data that determines the underlying disease, the damage to a particular system. V.I. Lenin defined the role of sensation as the first reflection of objective reality in human consciousness: “Sensation is a subjective image of the objective world” (Pol. sobr. soch. vol. 18, p. 120). However, mastering only the technique of examining a patient is not enough; one must strive to know the pathogenesis of each symptom, understand the connection between symptoms, because sensation is only the first stage of cognition, and in the future, the content of sensations, with the help of thinking, must be transformed into concepts, categories, laws, etc. If sensations are not subjected to appropriate thinking processing, they can lead to erroneous judgments in diagnosis. If using the clinical method it is not possible to make a diagnosis or it needs to be clarified, then they resort to laboratory and instrumental examination methods, in particular biochemical, serological, radiological, ECG and EEG studies, functional (spirometry, dynamometry, etc.) and other research methods, as well as subsequent monitoring of the patient.
The widespread introduction into clinical practice of various instrumental and laboratory research methods, having significantly increased the efficiency of diagnosis, has simultaneously increased the possibility of side effects on the patient’s body. In this regard, there was a need to develop certain criteria for the usefulness and safety of diagnostic methods. Research must be safe, accessible, economical, reliable and accurate, and must be stable and unambiguous in the results obtained with a minimum number of deviations. The lower the number of erroneous results, the higher the specificity of the research methodology. The examination of the patient must be purposeful, organized, and not spontaneous, for which the doctor must have a certain examination scheme and an assumption about the nature of the disease. Speaking about the direction of the diagnostic examination, two ways should be distinguished: the first is the movement of medical thought from the study of the symptom to the diagnosis, the second, called methodological or synthetic, consists of a comprehensive examination of the patient “from head to toe”, with full consideration of anamnesis data, objective and laboratory examination, regardless of the severity and nature of symptoms. The second way is more labor-intensive; it is resorted to even when the diagnosis seems clear “at first glance.” This method of examining patients is usually taught in medical institutes. The current state of science allows us to study the functional and structural state of a person at the following levels: molecular, cellular, tissue, organ, systemic, organismal, social, environmental. It should be borne in mind that the non-detection of pathological changes in the body is the same objective fact as the identification of certain symptoms.
A certain direction must exist when conducting laboratory research. You should not prescribe too many laboratory tests, and if they also do not give very clear results, they not only do not clarify the diagnosis, but even confuse it. Laboratory assistants, endoscopists, and radiologists can also make mistakes. And yet, many tests and instrumental studies are more useful than dangerous if they are carried out correctly, in accordance with indications and in non-invasive ways.
At the same time, numerous studies become flawed and fruitless, prescribed or interpreted incorrectly, haphazardly, with insufficient understanding of their clinical significance and with an erroneous assessment of the results obtained, a weak ability to connect the results found, overestimation of some studies and underestimation of other studies. Let's give an example. Once, within one week, our viral hepatitis clinic began to receive alarming conclusions from the laboratory about very low numbers of prothrombin index in a number of patients, which was in clear contradiction with general condition and other biochemical indicators in most of them. It turned out that the laboratory assistant made a gross technical error when testing the blood. But a sharply reduced prothrombin index in such patients is one of the most serious indicators of liver failure, requiring the use of urgent and special therapeutic measures. Laboratory data should be treated soberly and critically; laboratory and instrumental data should not be overestimated in the examination of patients. If, after examining patients and using laboratory and instrumental methods, it is not possible to make a diagnosis, then they resort (if the patient’s condition allows) to follow-up observation. Subsequent observation of the development of the pathological process, especially in infectious diseases characterized by a cyclical course (with the exception of sepsis), often makes it possible to come to the correct diagnostic conclusion. Avicenna already knew about follow-up observation as a diagnostic method and widely recommended its implementation in practice: “If it is difficult to determine the disease, then do not interfere and do not rush. Truly, either the (human) being will prevail over the disease, or the disease will be determined!” (cited from Vasilenko V. X., 1985, pp. 245-246). I.P. Pavlov constantly demanded to “observe and observe!” The ability to observe should be cultivated in oneself from school, to develop visual acuity, which is especially important in the diagnostic process. Outstanding clinicians of the past were distinguished by their ability to observe. The ability to observe requires a lot of patience, concentration, and slowness, which usually comes with experience.
My teacher, the famous infectious disease professor Boris Yakovlevich Padalka, possessed enviable patience and thoroughness when studying patients and persistently instilled these qualities in his employees and students. He never tired of listening to the complaints of patients, their stories about their illness, often confused, fragmentary, and sometimes ridiculous, incoherent. We, the employees who participated in the rounds, were sometimes very physically tired and sometimes silently scolded the professor for his, as it seemed to us, petty meticulousness. But over time, we became convinced of the usefulness of such a thorough examination of patients, when finding out subtle facts and symptoms helped to make a correct diagnosis. Boris Yakovlevich, regardless of the severity of the patient and the nature of his illness, always examined the patient in detail, did it slowly and strictly consistently, systematically examining the condition of all the patient’s organs and systems.
In 1957, while on a business trip in the city of U., I was invited for a consultation with a high-fever, middle-aged patient with an unclear diagnosis. Among those who observed the patient in the hospital there were also experienced diagnosticians, so I decided to examine the patient, like my teacher - as carefully and thoroughly as possible. And so, in the presence of several local specialists who had little faith in my luck, I began to slowly and strictly consistently and methodically examine the patient. Having examined the cardiovascular system, gastrointestinal tract, and urinary system, I was unable to “catch on” to anything that would explain the patient’s condition, but when it came to the respiratory organs, percussion was able to reveal the presence of fluid in the pleural cavity and diagnose exudative pleurisy. Subsequently, the diagnosis was completely confirmed and the patient recovered. The diagnosis turned out to be not at all difficult and was overlooked by local doctors not out of ignorance, but out of inattention. It turned out that in the last two days before my examination, the patient was not examined by the attending physician, and during this period the main accumulation of fluid in the pleural cavity occurred. In diagnostics, it is better to honestly and courageously admit your ignorance and state “I don’t know” than to tell lies, inventing false diagnoses and causing harm to the patient, while discrediting the doctor’s title.
It should be noted that the most characteristic clinical symptoms and the most adequate laboratory tests correspond to a certain stage of the disease. For example, in typhoid fever, it is easier to isolate a blood culture in the 1st week of the disease, while the Widal agglutination test gives positive results only from the beginning of the 2nd week, when specific agglutinins accumulate in the blood. Using technical innovations in diagnosis, one must not, however, fall into naked technicalism, remembering that the technicalization of diagnosis does not replace the direct clinical study of the patient, but only helps him. M. S. Maslov (1948) emphasized the conventionality of functional, biochemical and instrumental research methods and warned about the danger of fetishizing numbers.
When starting to examine a patient, the doctor must remember the impression he makes on him already at the first meeting, so you cannot examine the patient in the presence of strangers. In the room where the examination is being carried out, there should be only two people: the doctor and the patient, and if the child is sick, then only his relatives - in fact, this is the main meaning of the “doctor’s office”. If the first meeting between the doctor and the patient is unsuccessful, then proper psychological contact may not arise between them, but during this meeting the doctor must get to know the patient as a person, make a favorable impression on him, and win his trust. The patient must feel his true friend in the doctor, open up to him, understand the need to be frank with him, in turn, the doctor must be able to gather himself internally. A doctor needs to develop the professional ability to completely switch gears and immerse his thoughts into his work as soon as he finds himself at his workplace. Only if good psychological contact is established between the doctor and the patient, can one count on a complete examination of the patient, subsequent formulation of the correct diagnosis and prescription of individualized treatment. Only as a result of direct communication between the doctor and the patient, which cannot be recorded on paper, can one obtain a complete picture of the disease and the patient’s condition.
In conclusion, I would like to emphasize once again that a well-collected anamnesis, a skillfully and thoroughly conducted objective examination, and correctly interpreted examination data enable the doctor in most cases to make the correct diagnosis. And although this trivial truth is known to everyone, it is constantly underestimated. As a very young doctor, I once, together with an equally inexperienced colleague, tried to make a diagnosis of a feverish middle-aged patient who was distinguished by his silence and reticence. Having examined the patient, we did not find any changes that could explain the presence of a temperature reaction. Remaining in the clinic after a working day, we went through dozens of diseases, built more than one diagnostic hypothesis, but did not come to a definite conclusion. The next morning, we asked an associate professor of our department, an elderly and very experienced infectious disease specialist, to look at our mysterious patient. We had little doubt that the patient would present certain difficulties for our senior comrade. The associate professor, having questioned the patient, threw back the blanket and immediately discovered a focus of erysipelas on the patient’s lower leg, but we examined the patient only up to the waist and did not pay any attention to his legs. My young colleague (later a professor-therapist) and I were severely embarrassed, but we made an unequivocal conclusion for ourselves: the patient should always be examined from head to toe!
The human genius created “The Divine Comedy”, “Faust”, “Don Quixote”, “Eugene Onegin” and other great works that everyone talks about, but few people read or re-read, and everyone knows about the importance of clinical diagnostic methods, but not everyone makes full use of them.
Machine diagnostics.
Achievements of science and technology have penetrated into various fields of knowledge, including clinical medicine, facilitating the solution of many research and practical problems. Machine diagnostics is a tool of knowledge and clinical medicine must boldly enter into an alliance with mathematics and mathematical logic. Therefore, one cannot refuse the benefits of industrialization in the field of clinical diagnostics, while trying to maintain as much personal contact between the doctor and the patient as possible. However, technology, no matter how perfect it may be, cannot replace a doctor in studying the patient as an individual. All prominent and authoritative clinicians constantly emphasize the leading role of the clinic and the practitioner in reconstructing the picture of the disease based on subjective and objective data, as well as clinical analysis of laboratory test results. A cybernetic machine cannot operate with dialectical logic, without which the formulation of an individual diagnosis or a diagnosis of a patient is unthinkable. Cybernetic diagnostic methods are processes of processing information through a specific algorithm, the development of which involves three main stages: a) collecting information about the patient and storing information, b) analyzing the collected information, c) assessing data and making a diagnosis. It should be remembered that the task for a computer is made by a person, not a machine, a person “puzzles” the machine and the diagnostic effect will depend on how correctly the program for the machine was compiled.
Logic of diagnosis.
One of the most complex areas of cognitive activity is the diagnostic process, in which the objective and subjective, reliable and probabilistic are very closely and multifacetedly intertwined. The diagnosis is special kind cognitive process. “Cognition” means access to knowledge. This is a socio-historical process of human creative activity, forming his knowledge, on the basis of which the goals and motives of human actions arise. There are two main directions in the theory of knowledge - idealism and materialism.
Idealism reduces knowledge to self-knowledge of the “world spirit” (Hegel), to the analysis of a “complex of sensations,” denying the possibility of knowing the essence of things. Materialism proceeds from the fact that knowledge is a reflection of the material world, and reflection is a universal form of adaptation of the organism to external cause-and-effect relationships in the environment. The dialectical-materialist theory of knowledge considers practical activity as the basis of knowledge and a criterion for the truth of knowledge. There should be only one method of cognition - the only correct dialectical-materialist one.
Dialectics, if it claims to be successful, must be closely connected with the materialist theory of knowledge and dialectical methodologies of thinking. Dialectics presupposes a high culture of dialectical thinking of a doctor. All stages and aspects of cognition in any field are dialectically interconnected and permeate each other. Contemplating an object, a person, as it were, “imposes” on it the historically formed skills of its processing and use, and thereby this object appears before the person as the goal of his action. Living contemplation of objects is thus a moment of sensory-practical activity, carried out in such forms as sensation, perception, representation, etc.
Diagnosis methodology is a set of cognitive tools, methods, and techniques used in recognizing diseases. One of the sections of the methodology is logic - the science of the laws of thinking and its forms, which began with the works of Aristotle. Logic studies the course of reasoning and inference. The logical activity of thinking is carried out in such forms as concept, judgment, inference, induction, deduction, analysis, synthesis, etc., as well as in the creation of ideas and hypotheses. The doctor must have an understanding of different forms of thinking, as well as distinguish between skills and abilities, since the conscious nature of human activity is determined by a system of knowledge, which in turn is based on a system of skills and abilities, which are the basis for the formation of new skills and abilities. Skills are those associations that make up a stereotype, are reproduced as accurately and quickly as possible and require the least expenditure of nervous energy, while skill is the application of knowledge and skills in given specific conditions.
A concept is a thought about the characteristics of objects; with the help of concepts, similar and essential features of various phenomena and objects are identified and fixed in words (terms). The category of clinical concepts includes symptom, symptom complex, syndrome.
Judgment is a form of thought in which something is affirmed or denied regarding objects and phenomena, their properties, connections and relationships. Judging the origin of any disease requires knowledge not only of the main causative factor, but also of many living conditions, as well as heredity.
Inference is a form of thinking that results in a new judgment containing new knowledge from one or more known concepts and judgments. One type of inference is analogy - an inference about the similarity of two objects based on the similarity of individual features of these objects. Inference by analogy in classical logic is a conclusion about the belonging of a given object to a certain characteristic, based on its similarity in essential features with another individual object. The essence of inference by analogy in diagnosis is to compare the similarities and differences of symptoms in a particular patient with the symptoms of known diseases. M. S. Maslov (1948) noted that “you can only differentiate what is suspected in advance” (p. 52). Diagnosis by analogy is of great importance in recognizing infectious diseases during epidemics. The degree of probability of inference by analogy depends on the significance and number of similar features. I. N. Osipov, P. V. Kopnin (1962) warn about the need for caution and criticality when diagnosing by analogy. The dangerous thing about this method is the lack of a permanent plan for a systematic comprehensive examination of the patient, since the doctor in some cases examines the patient not in a strictly defined order, but depending on the leading complaint or symptom. At the same time, the analogy method is a relatively simple and frequently used method in recognizing diseases. In clinical medicine, this method is almost always used, especially at the beginning of the diagnostic process, but it is limited and does not require the establishment of comprehensive connections between symptoms and the identification of their pathogenesis.
An important place in diagnosis is occupied by such a logical technique as comparison, with the help of which the similarity or difference of objects or processes is established. Comparison is a widespread cognitive technique, which doctors often resorted to even in the time of Hippocrates, during the empirical period of the development of medicine. You can compare different objects, processes, phenomena, both qualitatively and quantitatively and in different respects. Not every comparison is valuable for diagnosis, so it must be carried out according to certain rules, including A. S. Popov,
V. G. Kondratyev (1972) include the following: a) determine, at least approximately, the range of the most likely diseases with which comparison will be made; b) identify leading symptoms or syndromes from the clinical picture of the disease; c) identify all nosological forms in which this symptom or syndrome exists; d) compare all the signs of a specific clinical picture with the signs of an abstract clinical picture; e) exclude all types of diseases except one, the most likely in this case.
It is easy to see that consistent comparison of a specific disease with an abstract clinical picture, according to the specified rules, makes it possible to carry out differential diagnosis and constitutes its practical essence. Recognition of a disease is essentially always a differential diagnosis, because a simple comparison of two pictures of the disease - abstract, typical, contained in the doctor’s memory, and concrete - in the patient being examined, is differential diagnosis.
Methods of comparison and analogy are based on finding the greatest similarity and least difference in symptoms. In cognitive diagnostic work, the doctor also encounters such concepts as essence, phenomenon, necessity, chance, recognition, recognition, etc.
The essence is inner side object or process, while the phenomenon characterizes the external side of the object or process.
Necessity is something that has a cause in itself and naturally follows from the essence itself.
Accident is something that has a basis and reason in something else, that follows from external or cortical connections, and because of this it may or may not happen, it can happen one way, but it can also happen in another way. Necessity and chance transform into each other as conditions change; chance is both a form of manifestation of necessity and an addition to it.
A precondition for any cognitive process, including diagnostic, is the recognition and recognition of the studied and related, as well as similar phenomena and their aspects in the most various options(K. E. Tarasov, 1967). The act of recognition is limited only to the fixation and foundation of a holistic image of an object, object, phenomenon, its general appearance according to one or more characteristics. Recognition is associated with concrete sensory activity, is a manifestation of memory, comparable to the process of designation, and is accessible not only to humans, but also to higher animals. Thus, recognition is limited to the reproduction of a complete image of an object, but without penetration into its inner essence. The act of recognition is a more complex process that requires penetration into the hidden internal essence of a phenomenon, subject, object, establishing, on the basis of a limited number of external signs, the specific structure, content, cause and dynamics of this phenomenon. Recognition is comparable to the process of establishing and revealing the meaning of an object, taking into account its internal and external connections and relationships. However, recognition should not be identified with scientific knowledge, since it is subordinated to the goals of practical change, transformation of the subject and has its own characteristics in each area.
What is common to recognition and recognition is that the train of thought goes from sign to phenomenon on the basis of preliminary knowledge, familiarity with the phenomenon as a whole and its most general specific features. However, acts of recognition and recognition in practical life They do not appear in isolation; they combine, complementing each other. When making a diagnosis by analogy, first of all, they resort to a simple recognition method and recognize the signs of a previously known abstract disease in the studied symptoms of the disease. When conducting a differential diagnosis and especially an individual diagnosis (i.e., diagnosing a patient), the doctor also uses the recognition method, since a more in-depth penetration into the essence of the disease is required, it is necessary to find out the relationship between individual symptoms, and to know the personality of the patient.
Thus, in diagnosis, two types of cognition processes can be distinguished, of which the first is the simplest and most common, based on analogy and recognition, when the doctor learns what he already knows, and the second, more complex, based on the act of recognition, when knowledge of a new combination of elements, that is, the individuality of the patient is learned.
Even more complex methods in the epistemological process are induction and deduction. Induction (Latin inductio - guidance) is a research method consisting in the movement of thought from the study of particulars to the formulation of general provisions, that is, conclusions going from particular provisions to general ones, from individual facts to their generalizations. In other words, diagnostic thinking in the case of induction moves from individual symptoms to their subsequent generalization and establishment of the form of the disease, diagnosis. The inductive method is based on an initial hypothetical generalization and subsequent verification of the conclusion based on the observed facts. The conclusion obtained inductively is always incomplete. V.I. Lenin pointed out: “The simplest truth, obtained by the simplest inductive method, is always incomplete, because it is always incomplete” (Works, vol. 38, p. 171). Conclusions obtained through induction can be verified in practice deductively, by deduction.
Deduction (Latin deductio - inference) is an inference that moves, in contrast to induction, from knowledge of a greater degree of generality to knowledge of a lesser degree of generality, from perfect generalization to individual facts, to particulars, from general provisions to particular cases. There are a number of forms of deductive reasoning - syllogisms (Greek - syllogismus - obtaining a conclusion, drawing consequences); the construction of a series of dividing syllogisms gives the doctor’s analytical work a strict and consistent character. If the method of deduction is resorted to in diagnosis, then medical thinking moves from the supposed diagnosis of the disease to individual symptoms expressed in this disease and characteristic of it. The great importance of deductive inferences in diagnostics is that with their help previously unnoticed symptoms are identified, it is possible to predict the appearance of new symptoms characteristic of a given disease, that is, using the deductive method, you can check the correctness of diagnostic versions in the process of further monitoring of the patient.
In diagnostic practice, the doctor must resort to both induction and deduction, and subject inductive generalizations to deductive verification. Using induction or deduction alone can lead to diagnostic errors. Induction and deduction are closely related to each other and there is neither “pure” induction nor “pure” deduction, but in different cases and at different stages of the epistemological process, one or the other conclusion has a predominant meaning.
Of the three sections of diagnostics - semiology, research methodology and medical logic - the last section is the most important, because semiology and medical technology are of subordinate importance (V. A. Postovit, 1989). Every doctor, by the nature of his work, is a dialectician, but dialecticians can be spontaneous and firmly stand on the scientific positions of Marxist-Leninist dialectics. A doctor must possess scientific dialectical thinking. The ability to apply dialectics is what distinguishes dialectics from non-dialectics. Dialectical materialism makes it possible to penetrate into the secrets of a sick person and correctly recognize the nature of diseases. In contrast to agnosticism, which denies knowability and its internal laws, dialectical materialism, based on the data of science and the world-historical practice of mankind, resolutely denies the existence of the principle of unknowability and affirms the ability of science for limitless development. In pathology there is no unknowable, but only the still unknown, which will be known as medical science develops. Life irrefutably testifies that as clinical knowledge expands, new facts and new information about the patterns of development of pathological processes are constantly being discovered.
Knowledge of dialectics, as the basis of a materialistic worldview and a method of knowing the world around us, as emphasized by V. M. Syrnev and S. Ya. Chikin (1971), is necessary for students of any higher educational institution, and even more so for medical students and doctors, since everyday medical work is constantly connected with dialectical thinking. Unfortunately, the introduction of the dialectical method to students and young doctors is often carried out in isolation from practice, it is too theoretical and therefore poorly mastered, and logic - the science of the laws of thinking and its forms - is especially important for a doctor - neither high school, is not studied at all in medical school. The few manuals and diagnostic manuals say little about logic, and sometimes it is quite primitive, which creates a distorted idea and causes doctors to have a negative attitude towards this type of science. M. S. Maslov (1948) gives the following recommendations for the use of the dialectical method in clinical diagnosis: both in the anamnesis and in the symptoms, highlight the decisive link, taking into account the real, specific living conditions and environment of the patient. Keep in mind that social, economic and everyday factors influence the causes and course of the disease, and that the patient’s reactivity also changes depending on environmental conditions. Diseases almost always affect an entire system of organs and often the entire organism, therefore, basing the diagnosis and prognosis only on morphological data and only on certain organs taken in isolation, without taking into account the whole organism, is clearly not enough and must necessarily be supplemented by a study of functions.
V. X. Vasilenko (1985) includes the following as modern principles of general diagnostics: a) a disease is both a local and general reaction, b) the body’s reactions depend on many factors - illnesses suffered in the past, genetic factors, changes in reactivity, etc. , c) the patient’s body is a single whole, organs and systems, including higher nervous activity, are closely interconnected, therefore, during the disease, not only local, but also general phenomena arise, d) the body should be studied in its unity with the external environment, which can contribute to the emergence and development of the disease, e) when studying the body, it is necessary to take into account the role of higher nervous activity, temperament, changes in the neurohumoral regulation of life processes, f) the disease is not only somatic, but also mental suffering. There are several forms of logic: formal, dialectical and mathematical logic. But perhaps those authors are right who recognize the existence of only one logic, which has 3 aspects: formal, dialectical and mathematical or symbolic logic. Formal logic is a science that studies forms of thought - concepts, judgments, inferences, evidence. The main task of formal logic is to formulate laws and principles, compliance with which is a necessary condition for achieving true conclusions in the process of obtaining inferential knowledge. The beginning of formal logic was laid by the works of Aristotle. Thus, formal logic is the science of forms of thinking, but without studying their origin and development, which is why V.I. Lenin called such forms “external” in comparison with the deep essence of dialectical logic. F. Engels pointed out that formal logic is only a relatively correct theory of the laws of thinking, he called it “ordinary” logic, the logic of “household use” (F. Engels. Dialectics of Nature).
Medical thinking, like any other, is characterized by universal logical characteristics and laws of logic. The theory of knowledge of Marxism-Leninism reveals the basic principles and most general laws of knowledge, regardless of the area in which it occurs cognitive activity. Diagnostics should be considered as a unique, specific form of cognition, in which its general principles are simultaneously manifested.
A.F. Bilibin, G.I. Tsaregorodtsev (1973) emphasized that the diagnostic process has no chronological and spatial boundaries separating sensory and logical cognition. By teaching university students how to methodically examine patients by organs and systems, we thereby teach them the techniques of formal logic. Formal logic is not a special methodology, although it is used as a method for explaining new results in the thinking process. When assessing the logic of a doctor’s reasoning, they primarily have in mind the formal-logical coherence of his thinking, that is, formal logic. However, it would be wrong to reduce the logical mechanism of medical thinking only to the presence of formal logical connections between thoughts, in particular between concepts and judgments.
The one-sidedness and insufficiency of formal logic, as emphasized by S. Gilyarovsky and K. E. Tarasov (1973), lies in the fact that it is distracted from the content of scientific concepts, the degree of accuracy, completeness and depth of reflection of objective reality in them. Back in the last century, L. Bogolepov (1899) tried to present the laws of medical thinking based on the principles of formal logic and identified the following types diagnostic thinking: 1) intuitive method, 2) simple method, 3) differential method, 4) exclusion method, 5) specific difference method, 6) deductive method and 7) analytical method. The above classification by L. Bogolepov is quite formal and schematic; the presented types of diagnostic thinking are not logically interconnected, do not complement each other and do not reflect the actual process of diagnostic medical thinking. The above is an example of how ignoring the laws of dialectics makes a generally meaningful classification lifeless. Despite its limited capabilities, formal logic is necessary and useful for mastering dialectical logic.
Dialectical logic, being higher than formal logic, studies concepts, judgments and inferences in their dynamics and interconnections, exploring their epistemological aspect. The basic principles of dialectical logic are the following: objectivity and comprehensiveness of research, the study of a subject in development, the disclosure of contradictions in the very essence of subjects, the unity of quantitative and qualitative analysis, etc.
V.I. Lenin formulated the main 4 requirements of dialectical logic: 1) study the subject under study comprehensively, revealing all its connections and mediations; 2) take the subject in its development, “self-expression” of changes according to Hegel; 3) include truth and practice in the full definition of the subject as a criterion; 4) remember that there is no “abstract” truth, truth is always concrete” (Poln. sobr. soch. vol. 42, p. 290).
Karl Marx emphasized: “The concrete is concrete because it is a synthesis of many determinations, therefore unity is diverse. In thinking, therefore, it appears as a process of synthesis, as a result, and not as a starting point, although it represents a real starting point and, as a result, also a starting point of contemplation and representation” (K. Marx and F. Engels. Works, ed. 2nd, vol. 12, p. 727).
What does concrete mean in epistemology? This is a system of concepts, formulations, definitions that characterize the specificity of an object, its features, logically related to each other. V.I. Lenin, defining the essence of dialectical logic, wrote: “Logic is a teaching not about external forms of thinking, but about the laws of development of “all material, natural and spiritual things, that is, the development of all the concrete content of the world and knowledge of it, i.e. . e. the result, the sum, the conclusion of the history of the knowledge of the world” (Poln. sobr. soch. vol. 29, p. 84) and further: “...The individual does not exist except in the connection that leads to the general. The general exists only in the individual, through the individual” (Poln. sobr. soch. vol. 29, p. 318). “To really know a subject,” said V.I. Lenin, one must embrace and study all its sides, all connections and “mediation.” We will never achieve this completely, but the requirement of comprehensiveness warns us against mistakes” (Poln. sobr. soch. vol. 42, p. 290). V.I. Lenin persistently emphasized in his works: “Dialectics requires a comprehensive account of relationships in their concrete development, and not pulling out a piece of one, a piece of another” (Poln. sobr. soch. vol. 42, p. 286).
The diagnostic process is a historically developing process. The patient is examined throughout his stay under the supervision of a doctor in a clinic or outpatient setting. M.V. Chernorutsky (1953) said about the dynamism of the diagnostic process: “The diagnosis is not complete, since the disease is not a condition, but a process. A diagnosis is not a one-time, temporarily limited act of cognition. The diagnosis is dynamic: it develops along with the development of the disease process, with the course and course of the disease” (p. 147).
S. P. Botkin emphasized: “... the diagnosis of a patient is a more or less probable hypothesis that must be constantly checked: new facts may appear that can change the diagnosis or increase its probability” (Course of the clinic of internal diseases and clinical lectures. M. , Medgiz, 1950, vol. 2, p. 21). The diagnosis never ends as long as the patient’s pathological process continues; the diagnosis is always dynamic, it reflects the development of the disease. S. A. Gilyarevsky (1953) believed that a restructuring of the diagnosis is possible under the following circumstances: a) when, as a result of the evolution of the disease process, new conditions arise, b) when, during the examination of the patient, the entire complex of symptoms was not expressed and therefore the diagnosis, despite its manifestations, needs addition and clarification, c) when the patient has two diseases at the same time, but one of them, being pronounced, served as the basis for the initial diagnosis, and the second, weakly manifested, is recognized later, d) when the initial diagnosis was incorrect. In the dynamics of the pathological process, the doctor must be able to correctly combine the data of his own and instrumental research with the results of laboratory tests, remembering that they change during the course of the disease. A diagnosis that is correct today may become incorrect or incomplete within a few weeks and even days, and sometimes even hours. Both the diagnosis of the disease and the diagnosis of the patient are not a frozen formula, but change along with the development of the disease. The diagnosis is individual not only in relation to the patient, but also in relation to the doctor. The path to diagnosis should not pass through complex, but through simpler concepts.
The pathogenesis of the disease, which is a dialectical process, requires studying the source, nature and direction of development of the pathological process. In this case, the source is understood as the internal impulse of the “self-propulsion” of the disease, the nature of development is revealed by the law of the transition of quantitative changes into qualitative ones, and the direction is revealed by the law of negation of negations (S. A. Gilyarevsky, K. E. Tarasov, 1973). Matter governs itself according to the laws of dialectics, of which 3 laws, closely related to each other, are universal: 1) the law of unity and struggle of opposites, 2) the law of the transition of quantity into quality, 3) the law of the negation of negations. The doctor must constantly keep in mind that the body, both healthy and sick, is a single whole; all systems, organs and tissues of the entire organism are in the closest connection and complex interdependence on each other.
A living organism is not an arithmetic sum of its parts - it is a new quality that arose as a result of the interaction of individual parts under certain conditions external environment. But, emphasizing the importance of the whole, one cannot underestimate the role of the local, it is not without reason that I. P. Pavlov pointed out: “It goes without saying that a living organism is a whole, but to deny an element is nonsense, ignorance, misunderstanding” (cited by A . F. Bilibin, G. I. Tsaregorodtsev, 1973, p. 63).
Unfortunately, the doctor sometimes sees separately the liver, stomach, nose, eyes, heart, kidneys, bad mood, suspiciousness, depression, insomnia, etc. But it is necessary to cover the patient as a whole, to create an idea of the individual! At the same time, some doctors don’t even want to hear about this, considering it to be a rationalization, while rhetorically asking the question: “What does personality mean? We are always studying it! However, this is just an empty phrase! Doctors have long known that the state of the nervous system affects the course of somatic processes. M. Ya-Mudrov noted: “... the sick, suffering and despairing, thereby deprive themselves of life, and die from the mere fear of death.” (Izbr. proiz. M., 1949, p. 107). The French surgeon Larrey claimed that the wounds of the victors heal faster than those of the vanquished. Any somatic disorder leads to a change in the psyche and vice versa - a changed psyche affects somatic processes. A clinician should always be interested in the mental world of a person, his relationship to people, society, nature; The doctor is obliged to find out everything that shapes a person and influences him. According to the ancient scientists of Greece, the greatest mistake in the treatment of diseases was that there are doctors for the body and doctors for the soul, while both are inseparable, “but this is precisely what the Greek doctors do not notice, and that is the only reason why they so many diseases are hidden, they do not see the whole” (quoted by V. Kh. Vasilenko, 1985, p. 49). Plato argued: “The greatest mistake of our days is that doctors separate the soul from the body” (quoted by F.V. Bassin, 1968, p. 100). The unity of the body’s functions and reactions is due to the interconnected mechanisms of nervous and humoral regulation. The highest center regulating autonomic processes is the hypothalamus, which has vascular and neural connections with the pituitary gland, forming the hypothalamic-pituitary system. M.I. Astvatsagurov reported back in 1934 that the presence of an organ that carries out the primary connection between mental and somatic functions has been established. This organ is the ganglia of the diencephalon - the visual thalamus and the striatum, which are closely related to the autonomic system and are the phylogenetic roots of primitive emotions. Due to the presence of unity of body functions, the local pathological process can become generalized. The functional unity of content and form creates a certain integral structure, which is not just a collection of individual elements, but also a system of connections and interactions. It should be borne in mind that each structure can have several functions interconnected into a single integrated system, therefore it is more correct to talk about a functional system rather than a function. F. Engels pointed out: “All organic nature is one continuous proof of the identity and inseparability of form and content. Morphological and physiological phenomena, form and function mutually determine each other” (K-Marx and F. Engels. Works, ed. 2, vol. 20, pp. 619-620). To separate function from structure or structure from function is metaphysical and contrary to the principles of dialectical thinking. Structural changes almost always lead to functional shifts, while the latter can occur without significant structural changes, therefore in life the mechanism of dependence of function on structure is more noticeable and the influence of function on structure is less pronounced. In this regard, functional diagnostics usually precedes other types of diagnosis, in particular morphological, while uniting all types of diagnosis into a single holistic, detailed diagnostic concept of a single focus and integrating everything general meaning, while the meaning of morphological, etiological and other diagnoses is more narrow.
The narrow specialization of doctors leads to the fact that they forget about the integrity of the human body, that he is an individual. Delving deeper into the study of “molecular disorders,” which in itself is important and progressive, one cannot lose sight of the whole organism with its highly organized and subtle psyche. Therefore, narrow specialization, on the one hand, is very necessary, but on the other hand, it is not always useful, since in this case the understanding of the patient’s body as a whole disappears. The perception of even the simplest phenomenon occurs in the form of an image, holistic, and not fragmented into separate component parts. V. X. Vasilenko (1985), speaking about the tasks of a diagnostician, pointed out that his task “is not only to determine the essence, the disease of the patient, but also to recognize his special features, i.e. his individuality, almost just as a portrait artist depicts not a person in general, but a very specific face and personality; without these data there can be no medical art” (p. 35). Dialectical logic does not deny formal logic, but acts through it, on the basis of a specific synthesis of its operations, overcoming the limitations of each of them.
Formal and dialectical logic are different stages in the historical development of human thinking. Formal logic, as a lower stage in the history of thinking, is included in dialectical logic, and the latter mediates modern formal logic, giving it new content in accordance with the requirements and demands of scientific thought. Therefore, in the diagnostic process it is impossible to artificially separate formal and dialectical logic, because at any stage of recognition the doctor thinks both formally and dialectically. However, to make a methodologically sound final diagnosis, it is not enough for a doctor to apply only the laws of formal logic - they must be comprehended and supplemented by the laws and categories of dialectical logic. The dialectical method of thinking exists and operates in every area of scientific epistemology, but this, however, does not eliminate its specificity. Mathematical logic is not a special form of logic, but represents modern stage development of formal logic. The merit of mathematical logic lies in the creation of special logical systems (calculi) and in the development of formalization methods. Mathematical logic is even more formalistic than classical formal logic. However, the diagnosis is not arithmetic sum patterns of a living biological system, calculated using a computer, diagnosis is not a simple addition of the symptoms of a disease, but a subtle process of synthesis and creativity.
The diagnostic process is associated with obtaining, comprehending and processing numerous anamnestic and laboratory data, objective research data, sometimes obtained using complex instruments, and in some cases as a result of long-term observation of the patient, therefore the processing of such information is possible only using methods not only formal , but also dialectical logic, and the latter are accessible only to a doctor, and not to a machine. Mathematical or symbolic logic is used in solving computer problems. One of the branches of mathematical logic is probabilistic logic, which assigns not two, but many truth values to judgments.
There is no special medical logic or special clinical epistemology. All sciences have the same logic, it is universal, although it manifests itself somewhat differently, because it acquires some originality of the material and the goals with which the researcher is dealing. Methodology, epistemology, logic in all spheres of human activity are common, but the fact that they manifest themselves differently gives rise to the erroneous opinion that each science has its own logic.
Medical thinking is characterized by a single universal logic, its principles and laws, the application of which is an indispensable condition for the correctness of thinking and its effectiveness. The assertion that each science has its own special logic is baseless. But nevertheless, in logic, individual fragments can be identified that are most suitable for the logical form of a given particular scientific or professional activity. It should be noted that logic does not so much indicate the right paths as warn against incorrect, erroneous paths. In the diagnostic activity of a doctor, there is a complex dialectical-categorical synthesis of the inorganic and biological, biological and social, physiological and psychological, that is, a unique cognitive situation arises. At the same time, it should be borne in mind that the logic of diagnosis is not limited to the development of a ready-made system of means for recognizing the disease. It cannot be reduced to logical constructions of perception of known medical knowledge, to their deductive transformation. According to S.V. Cherkasov (1986), the logic of diagnosis should contribute to the development of the doctor’s creative and constructive abilities for abstract and intuitive thinking, the ability to separate the main and the secondary. The active and creative nature of clinical thinking is manifested not in the fact that the doctor’s thought ignores the logical correctness of creative constructions, but in the fact that it adequately reflects the general pattern and features of the course of the disease in their dialectical unity.
What is thinking? “Thinking is an active process of reflecting the objective world in concepts, judgments, theories, etc., associated with the solution of certain problems, with generalization and methods of indirect knowledge of reality; the highest product of brain matter organized in a special way” (Philosophical Dictionary, M., 1986, Politizdat, p. 295). Thinking is the process of human interaction with the social practice of work and life; it is never isolated from other manifestations of the psyche. There are different opinions regarding the interpretation of the concept of “clinical thinking”. A.F. Bilibin, G.I. Tsaregorodtsev (1973) believe that this concept includes not only the process of explaining observed phenomena, but also the doctor’s attitude towards them; clinical thinking is based on a variety of knowledge, on imagination, memory, fantasy, intuition , skill, craft and craftsmanship. Further, these authors point out that despite the fact that the doctor’s thinking should be logical and amenable to control and verification, it still cannot be mechanically identified with
formal-logical, philosophical and figurative-artistic. Clinical thinking, along with the general, also has unique specificity. And the peculiarity of medicine is that it is always connected with people, and each person is always individual (V. A. Postovit, 1989, 1990). A. S. Popov, V. G. Kondratyev (1972) give the following definition of clinical thinking: “Clinical thinking is understood as the specific mental activity of a practicing physician, ensuring the most effective use of theoretical and personal experience to solve diagnostic and therapeutic problems regarding a specific patient. The most important feature of clinical thinking is the ability to mentally reproduce a synthetic and dynamic internal picture of the disease” (pp. 24-25). According to these authors, the specificity of clinical thinking is determined by three features: a) the fact that the object of cognition is a person - a creature of extreme complexity, b) the specificity of medical tasks, in particular, the need to establish psychological contact with the patient, study him as an individual in diagnostic and therapeutic plans and c) constructing a treatment plan. It should be taken into account that the doctor is often forced to act in conditions of insufficient information and significant emotional stress, aggravated by a sense of constant responsibility.
Clinical thinking is also a logical activity to clarify a specific personality, therefore clinical thinking is always an active creative process. S. V. Cherkasov (1986) notes that clinical thinking is manifested not in the fact that the doctor’s thought ignores the logical correctness of theoretical constructs, but in the fact that it adequately reflects the general pattern and features of the course of the disease in their dynamic unity. The initial, motivating moment for clinical thinking and diagnosis is the symptoms of the disease. Clinical thinking requires a doctor’s creative approach to each specific patient, the ability to mobilize all knowledge and experience to solve a specific problem, be able to change the direction of reasoning in time, maintain objectivity and decisiveness of thinking, and be able to act even in conditions of incomplete information.
The culture of a doctor’s thinking is of great importance in recognizing diseases; a doctor who does not have sufficient culture and experience in clinical thinking often accepts probable conclusions as reliable.
In clinical work there are a lot of guesses, so-called hypotheses, so the doctor is obliged to constantly think and reflect, taking into account not only indisputable, but also difficult-to-explain phenomena. A hypothesis is one of the forms of the cognitive process. In diagnosis, hypotheses are very important. In its logical form, a hypothesis is a conclusion in which part of the premises, or at least one, is unknown or probable. The doctor uses a hypothesis when he does not have sufficient facts to accurately diagnose the disease, but assumes its presence. In these cases, patients usually do not have specific symptoms and characteristic syndromes, and the doctor has to follow the path of a probable, presumptive diagnosis. Based on the identified symptoms, the Doctor builds an initial hypothesis (version) of the disease. Already when complaints and anamnesis are identified, an initial hypothesis appears, and at this stage of the examination the doctor must freely move from one hypothesis to another, trying to construct the study in the most expedient way. A preliminary diagnosis is almost always a more or less probable hypothesis. Hypotheses are also important because, during the ongoing examination of the patient, they help to identify other new facts that may sometimes be even more important than those discovered previously, and also encourage the verification of existing symptoms and the conduct of additional clinical and laboratory tests. F. Engels pointed out the importance of hypotheses in knowledge: “The form of development of natural science, insofar as it thinks, is a hypothesis” (K. Marx, F. Engels. Works, 2nd ed., vol. 20, p. 555). Claude Bernard said that science is a cemetery of hypotheses, and D.I. Mendeleev argued: “... it is better to adhere to a hypothesis that may turn out to be incorrect over time than none” (1947, vol. 1, p. 150). There are general and specific or working hypotheses. In a general or scientific, real hypothesis, an assumption about the laws of natural and social phenomena is substantiated; in a particular hypothesis, an assumption about the origin and properties of individual facts, phenomena or events is substantiated. A working hypothesis provides one of the possible explanations or interpretations of a fact, phenomenon or event. A working hypothesis is usually put forward at the very beginning of the study and is more of an assumption that orients the research in a certain direction. If a general hypothesis is a form of development of purely scientific knowledge, then a particular one is used not only by science, but also has applied significance in solving practical problems. A general hypothesis, although with certain amendments, can provide an explanation of the phenomenon, which in a number of cases turns into reliable knowledge. A general hypothesis is always subject to proof, and a proven one turns into a reliable truth. In order for the general hypothesis to turn into reliable conclusions about the diagnosis during the period of studying the anamnesis and clarifying the patient’s complaints, it is necessary to obtain and take into account the data of an objective study.
A working hypothesis is an initial assumption that facilitates the process of logical thinking, helps to systematize and evaluate facts, but does not have the purpose of mandatory subsequent transformation into reliable knowledge. Each new working hypothesis requires new symptoms, therefore the creation of a new working hypothesis requires a search for additional, still unknown, signs, which contributes to a comprehensive study of the patient, deepening and expanding the diagnosis. The likelihood of working hypotheses is constantly increasing as they change and new ones appear.
A. S. Popov, V. G. Kondratyev (1972) highlight the following rules for constructing diagnostic hypotheses: a) the hypothesis should not contradict firmly established and practically proven provisions of medical science; b) a hypothesis should be built only on the basis of verified, true, truly observed facts (symptoms), and should not require other hypotheses for its construction; c) the hypothesis must explain all existing facts and none of them must contradict it. A hypothesis is discarded and replaced with a new one if at least one important fact (symptom) contradicts it; d) when constructing and presenting a hypothesis, it is necessary to emphasize its probabilistic nature, remembering that a hypothesis is only an assumption. Excessive enthusiasm for a hypothesis, combined with personal immodesty and an uncritical attitude towards oneself, can lead to a serious mistake. V. X. Vasilenko (1985) emphasized that hypotheses should be accessible to direct testing, and their number should be reduced. Diagnostic hypotheses are tested in practice. When constructing hypotheses, one should avoid haste in generalizations, do not attach the significance of a reliable truth to an unlikely hypothesis, and do not build hypotheses on unreliable symptoms, since the ultimate goal is to transform a diagnostic hypothesis into a reliable conclusion. A hypothesis is considered correctly formed in those cases when it corresponds to the facts, is based on them and follows from them, and if even one, but serious and reliable symptom contradicts the hypothesis, then such a hypothesis should be considered devoid of value and the doctor should discard it. In diagnostics, you need to be able to, in certain cases, refuse a diagnosis if it turns out to be erroneous, which is sometimes very difficult, sometimes even more difficult than making the diagnosis itself.
While being critical of a hypothesis, the doctor must at the same time be able to defend it, debating with himself. If a doctor ignores facts that contradict a hypothesis, then he begins to accept it as a reliable truth. Therefore, the doctor is obliged to look not only for symptoms that confirm his hypothesis, but also for symptoms that refute it, contradict it, which can lead to the emergence of a new hypothesis. The construction of diagnostic hypotheses is not an end in itself, but only a means for obtaining correct conclusions in recognizing diseases.
Diagnosis is a cognitive process, the essence of which is to reflect in the doctor’s mind objectively existing patterns caused by the pathological process in the patient’s body. The task of diagnosis in general comes down to creating a mental picture of the disease in a particular patient, which would be as complete and accurate a copy of the disease itself and the patient’s condition as possible. If the doctor manages to most fully achieve the identity of his thoughts with the true picture of the disease and the patient’s condition, then the diagnosis will be correct, otherwise a diagnostic error occurs.
The cognitive diagnostic process goes through all stages of scientific knowledge, following from simple to complex knowledge, from shallow to deeper knowledge, from collecting individual symptoms to their comprehension, establishing the relationship between them and drawing up certain conclusions in the form of a diagnosis. V.I. Lenin said: “Man’s thought endlessly deepens from phenomenon to essence, from essence of the first, so to speak, order to essence of the second order, etc. without end” (Poln. sobr. soch. vol. 29, p. 227). The doctor strives to recognize the disease by its sign, mentally moving from part to whole. Each stage of thinking is closely related to the next and intertwined with it. The diagnostic process follows from the concrete sensory to the abstract and from it to the concrete in thought, and the latter is the highest form of knowledge.
The movement of knowledge in the diagnostic process goes through the following 3 stages, reflecting the analytical and synthetic mental activity of the doctor: 1. Identification of all symptoms of the disease, including negative symptoms, during a clinical and laboratory examination of the patient. This is the phase of collecting information about the morbidity of a particular patient. 2. Understanding the detected symptoms, “sorting” them, assessing them according to their degree of importance and specificity, and comparing them with the symptoms of known diseases. This is the phase of analysis and differentiation. 3. Formulating a diagnosis of the disease based on the identified signs, combining them into a logical whole. This is the phase of integration and synthesis.
Diagnostics begins with analysis, with the study of subjective data, with an examination of the patient by organs and systems in a known sequence and the subsequent synthesis of the collected facts. When conducting analysis and synthesis, the doctor must follow the rules scientific observation which require:
1) objectivity, reliability, accuracy of the examination,
2) completeness, methodology and systematicity of the survey,
3) constant comparison of observed phenomena.
The above indicates that clinical diagnosis refers to complex medical activities that require the ability to analyze and synthesize not only the identified painful symptoms, but also the individuality of the patient, his characteristics as a person. Clinical diagnosis is based on the study of the patient, the knowledge and experience of the doctor, and his ability to apply his knowledge in practice in various conditions. The success of a doctor in recognizing diseases also depends on his mastery of the basics of logic - formal and dialectical. When making differentiation, the doctor strives to arrive at a clinical diagnosis when the direct symptoms fit into the clinical picture of one specific disease. All symptoms that do not correspond to a given disease will either speak against the diagnosis of this disease or indicate the presence of complications.
The diagnostic process, in contrast to scientific research, assumes that the essence of the recognized object, that is, the symptoms of the disease, is already known. In principle, diagnosis consists of two parts of the doctor’s mental activity: analytical and synthetic, and the main forms of thinking are carried out through analysis and synthesis. Any human thought is the result of analysis and synthesis. In the work of a clinician, analysis is practically carried out simultaneously with synthesis, and the division of these processes as sequential is very arbitrary.
Analysis is the mental division into separate parts of a studied object, phenomenon, their properties or relationships between them, as well as the isolation of its features for studying them separately, as parts of a single whole. It should be borne in mind that the disease is sometimes characterized by complex clinical manifestations and the doctor has to collect and analyze very extensive information about the patient and conduct a serious analysis. An object or process can be perceived as a whole without previous analysis, but in this case the perception more often remains superficial and shallow. The analysis process can be divided into a number of components, such as: listing information, grouping identified data into major and minor, classifying symptoms according to their diagnostic significance, identifying more or less informative symptoms. In addition, an analysis of each symptom is carried out, for example, its localization, qualitative and quantitative characteristic, connection with age, connection with the time of appearance, periodicity, etc. The main task of the analysis is to establish symptoms, determine among them significant and insignificant, stable and unstable, leading and secondary, helping to identify the pathogenesis of the disease. A. S. Popov, A. G. Kondratiev (1972) emphasize that the diagnostic information content and pathogenetic significance of symptoms often do not coincide: for example, such “minor” symptoms of diabetes mellitus as periodontal disease, furunculosis, itching of the skin may also be present with hidden course of the disease.
Synthesis is a more complex process than analysis. Synthesis, as opposed to analysis, is a combination various elements, sides of an object, phenomenon into a single whole. With the help of synthesis in diagnosis, all symptoms are integrated into a single connected system - the clinical picture of the disease. Synthesis is understood as the mental reunification into a single whole of the component parts or properties of an object. However, the synthesis process cannot be reduced to a simple mechanical addition of symptoms; each symptom must be assessed in dynamic connection with other signs of the disease and with the time of their appearance, that is, the principle of a holistic consideration of the entire complex of symptoms, in their relationship with each other, must be observed. Mechanical addition of individual symptoms without taking into account their relationship and assessing the dynamic significance of each of them leads to a distortion of the holistic picture and an error in diagnosis. In most cases, the identified symptoms are a reflection of only one disease, which the doctor must recognize), although the possibility of the presence of several diseases cannot be excluded. With the help of synthesis, all identified symptoms are combined into a single pathogenetic picture by combining individual symptoms into syndromes, initially establishing individual aspects of the diagnosis, the so-called “private diagnoses” and then synthesizing them to obtain a single picture of the disease with a single diagnosis. This is preceded by the identification of a complex of decisive, leading symptoms and their differentiation from secondary ones.
If in the first part of the diagnosis the doctor collects all the facts characterizing the disease, then in the second part a lot of creative work is carried out to critically evaluate these facts, compare them with others and formulate a final conclusion. The doctor must be able to both analyze and synthesize the obtained clinical and laboratory data. In the diagnostic process there is a unity of analysis and synthesis. M. S. Maslov (1948) emphasized that the alpha and omega of medical activity are analysis and synthesis. F. Engels pointed out: “Thinking consists as much in the decomposition of objects of consciousness into their elements as in the unification of interconnected elements into some unity. Without analysis there is no synthesis” (K. Marx, F. Engels. Works, vol. 20, p. 41). Analysis without subsequent synthesis may be fruitless. Analysis can provide a lot of new information, but numerous details come to life only in their connection with the whole organism, that is, in the case of a rational synthesis. Therefore, a simple collection of symptoms of a disease for diagnosis is not at all sufficient: thought processes are also required and, in addition, the activity of a doctor, based on observation and experience, which helps to establish the connection and unity of all detected phenomena. Thus, the diagnostic process consists of two stages: recognition and logical conclusion, on the basis of which the following 3 tasks are solved: 1) detection of symptoms of the disease, 2) correct interpretation of the identified signs of the disease, 3) drawing correct diagnostic conclusions.
In life, there are doctors who know propaedeutics and the symptoms of diseases very well, but, lacking the ability to think synthetically, remain poor diagnosticians. Here we are not talking about the doctor’s ignorance, but about his inability to think diagnostically. In this case, the doctor is likened to a bad mechanic who, having all the individual parts of the machine, cannot assemble it.
Clinical thinking has a dual character: the ability to record what is known and the ability to reflect on what is specific, identified during analysis. The diagnostic process is permeated with the analytical and synthetic mental activity of the doctor. It should be borne in mind that not all facts obtained during the examination of the patient are used in making a diagnosis. In the clinical picture there are also random, insignificant and even “extra” signs that not only do not help recognize the disease, but even interfere with diagnosis, leading the mind of a doctor, especially an inexperienced one, away from the main facts. The ability to select facts from redundant information indicates the doctor’s diagnostic abilities. When a doctor begins a diagnosis, identifying subjective and objective data about the disease, he immediately asks the question - which organ or organs are affected? This is how an attempt to make a morphological diagnosis is formed. Then the second question arises - what is the cause of damage to this organ or organs? Thinking in this direction, the doctor strives to establish an etiological diagnosis. And finally, when it is clear, at least in general terms, the main localization of the pathological process and the most likely cause of the disease, the doctor begins to mentally create a general picture of the disease, thus drawing up the pathophysiological or pathogenetic structure of the diagnosis.
When creating a diagnosis, the doctor must firmly rely only on facts, the course of his reasoning must be justified. The prominent Swiss clinician R. Hegglin pointed out: “It is difficult to describe in words, but what is most important at the patient’s bedside is the ability to intuitively, as if with an inner glance, grasp the entire clinical picture as a whole and connect it with similar previous observations. This quality of a doctor is called clinical thinking” (p. 19). The doctor must develop the ability to see the whole through the detail and be able to project the detail onto the whole. A. S. Popov, V. G. Kondratyev (1972) not without reason believe that the main thing in clinical thinking is the doctor’s ability to mentally construct a synthetic picture of the disease, to move from perceiving the external manifestations of the disease to reconstructing its pathogenesis. There is also an “internal picture of the disease,” that is, the picture of the disease that appears to the patient himself, his subjective assessment of his disease. The doctor’s task is to combine the actual picture of the disease and the internal picture of the disease into one whole, try to carry out an analysis, discard everything unnecessary and use what is valuable and important. Clinical thinking on the way to creating a diagnosis goes through successively certain stages. V.I. Lenin formulated the path to knowledge of truth as follows: “... from living contemplation to abstract thinking and from it to practice - such is the dialectical path to knowledge of truth, knowledge of objective reality” (Poln. sobr. soch. vol. 29, p. .152). S. A. Gilyarevsky (1953), I. N. Osipov, P. V. Kopnin (1962), V. M. Syrnev, S. Ya-Chikin (1971), S. A. Gilyarevsky, K. E. Tarasov (1973) and others believe that the diagnostic process goes through all three stages of scientific knowledge, namely: sensory contemplation, abstract thinking, and practice.
At the stage of sensory contemplation, the patient is examined, the obtained subjective and objective data are analyzed. This stage does not occur automatically and thoughtlessly; the doctor is already beginning to think about a possible diagnosis, so this stage is inextricably combined with the second stage - abstract thinking.
At the stage of abstract thinking, the doctor synthesizes the results of the examination, makes a diagnosis, considers the pathogenesis of each symptom and the disease as a whole, while clarifying the relationship of individual symptoms using clinical thinking. During the period of practice, based on the formulated diagnosis, treatment begins, the prognosis of the disease is determined, and preventive measures are planned.
Practice in medical diagnostics most specifically appears in two main forms: in the practical examination of the patient in order to recognize the nature of the disease and in recommendations for treatment and prevention. Practice is the basis of knowledge and the criterion of truth. During this period, the doctor checks the correctness of his conclusions and recommendations, and the check takes place in the dynamics of the disease while monitoring the results of treatment. In the dialectical understanding, the stage of practice is associated with both living contemplation and abstract thinking. Practice, as the criterion of truth, is charged with the task of identifying and correcting possible errors, admitted at the previous two stages of the cognitive process. Practice is also a stimulus for learning and searching for new things. Practice is of decisive importance in diagnosis, because the diagnosis is followed by practical measures. Practice is the criterion of the truth of knowledge. Through practice, a person influences nature and cognizes reality to the extent that he can practically master and change it. Dialectical materialism understands practice as the activity of people, through which they change phenomena, objects, and processes of reality. Therefore, the only criterion for the objective truth of a diagnosis is practice. Practice itself is a developing process, which is limited at each stage by production capabilities and its technical level. This means that practice is also relative, due to which its development does not allow truth to turn into dogma, into an unchanging absolute.
When we talk about “living contemplation” and not just “contemplation”, we emphasize active and methodical study the patient, purposeful action, and not passive “contemplation” of the patient, not a bare, mechanical collection of facts. It is in this phase that the purposeful collection and registration of observed phenomena, facts, and processes related to the disease occurs. All data obtained during the period of “living contemplation” must be specific and accurate, since on their basis the next period of the cognitive process is built - the period of “abstract thinking”. Incorrect judgments created at the second stage will lead to errors at the third stage of the cognitive process - practice.
F. T. Mikhailov (1965) notes that in the literature there is a tendency to present the diagnostic process as a kind of standard of transition from living contemplation (inspection, palpation, percussion, auscultation) to abstract thinking, and from there to practice. However, such an approach, according to F. T. Mikhailov (1965), is a manifestation of “philosophical naivety”, since the authors, forgetting about the universal nature of the main stages of cognition reflected in Lenin’s formulation, and trying to bring the stages of the diagnostic process under this position , do not take into account one essential feature - the doctor determines the patient has a disease already known to science, therefore the diagnostic process cannot be identified with the universal human process of cognition, with the goal of discovering something new in nature and society. Scientific activities is primarily associated with the discovery of a new phenomenon, and when making a diagnosis, the doctor establishes a disease that is already known, long discovered by science, in a particular patient. When diagnosing, the doctor, as it were, “rediscovers” a disease that is already known, while highlighting the individual characteristics of a particular patient. Examining a patient and making a diagnosis is a special kind of cognitive task, significantly different from scientific research. If the doctor encounters a completely new, still unknown disease (which in principle is not excluded, although it happens extremely rarely), then the diagnosis will not be established, because, as M. S. Maslov (1948) notes, “you can only diagnose what that they suspect in advance” (p. 52). Therefore, clinical diagnostics cannot be identified with scientific research, as is sometimes attempted, equating making a diagnosis with solving a research problem.
It should be noted that the division of the diagnostic process into individual stages is purely conditional; in real diagnostics, it is almost impossible to draw a line between the stages of this process, to determine exactly where one ends and the second begins, especially since in some cases the diagnosis proceeds so quickly, that its individual stages seem to merge into one continuous cognitive process. Thus, it is very difficult to draw a line between the stage (phase) of “living contemplation” and “abstract thinking,” because already during the period of questioning the patient, the doctor begins to carry out diagnostics. G. A. Zakharyin (1909) rightly pointed out: “It would be a mistake to think that recognition is done only after research... data obtained through questioning and objective research inevitably raise certain assumptions, which the doctor immediately tries to solve with verification questions and objective research... therefore, recognition is made during the research itself” (p. 18). Thus, G. A. Zakharyin emphasizes that it is a mistake to think that diagnosis is carried out only after the completion of the examination of the patient - it is already carried out during the examination itself. However, for didactic and educational purposes, we adhere to a certain sequence and stage-by-stage analysis of the progress of the diagnostic process, remembering that a clear and consistent alternation of phases of this process occurs only when analyzing patients for pedagogical and didactic purposes in teaching diagnostics with a methodological analysis of the cognitive process itself. In practice, when examining a patient, these stages are only partially preserved in their logical and chronological sequence; more often they are mutually intertwined and merged. The stages of cognition of objective truth, including the recognition of diseases, are so dialectically interconnected that it is almost impossible to separate them in time. Finding out the symptoms of the disease, classifying them into main and secondary, the doctor at the same time already thinks about the diagnosis. It is difficult to identify separate time stages when the doctor would only engage in “sensual contemplation” or “abstract thinking” in isolation from practice.
Existing methods diagnostics developed historically, arose and developed as logically interconnected stages of a single process. Therefore, it is impossible to artificially divide a single holistic diagnostic process into separate parts, separate periods, which are already beginning to act as independent types of diagnoses, in particular, the diagnosis of the disease and the diagnosis of the patient. IN real life The diagnostic process is continuous, strictly limited in time and there are no clearly defined periods or sequential transitions of the thought process in it, therefore the doctor classifies symptoms continuously, as if automatically during the examination of the patient.
Diagnostics(Greek diagnō stikos capable of recognizing) - a section of clinical medicine that studies the content, methods and successive stages of the process of recognizing diseases or special physiological conditions. In a narrow sense, diagnostics refers to the process of recognizing a disease and assessing the individual biological characteristics and social status of a subject, including a targeted medical examination, interpretation of the results obtained and their generalization in the form of an established diagnosis
Diagnostics As a scientific subject, it includes three main sections: semiotics; diagnostic methods examination of the patient, or diagnostic equipment; methodological foundations that determine the theory and methods of diagnosis.
Methods of diagnostic examination of a patient are divided into basic and additional, or special. Historically, the earliest diagnostic methods include the basic methods of medical research - anamnesis, examination of the patient, palpation, percussion, auscultation. Special methods are developed in parallel with the development of natural sciences and medical knowledge; they determine the high potential of diagnostic capabilities, including research at the subcellular level and processing of medical data using a computer. The practical use of special diagnostic methods is determined by modern requirements for clinical diagnosis, based on the nosological principle and including etiological, morphological, pathogenetic and functional components, which should sufficiently characterize the features of the onset and course of the disease. The most common special methods are X-ray diagnostics, radionuclide diagnostics , electrophysiological studies (incl. electrocardiography, electroencephalography, electromyography), functional diagnostic methods, laboratory diagnostics(including cytological, biochemical, immunological studies, microbiological diagnostics). Large hospitals and diagnostic centers use highly informative modern special methods - computer tomography, ultrasound diagnostics, endoscopy. Laboratory equipment, reagents and test results are subject to periodic special testing in order to control the quality of laboratory research. Diagnostic instruments and apparatus must also be subject to metrological control to ensure accuracy, reproducibility and comparability of the results of their use.
The use of special methods of diagnostic examination does not replace the diagnostic activity of a doctor. The doctor is obliged to know the capabilities of the method and avoid conclusions that are inadequate to these capabilities. For example, based on ECG changes without taking into account the clinical picture, such a conclusion as “decreased blood flow in the myocardium” is incorrect, because blood flow and blood supply to the myocardium cannot be measured electrocardiographically. The existing diversity and further development of special diagnostic methods imply improvement of the diagnostic process only in connection with mastering its methodological foundations and subject to a corresponding increase in the professional qualifications of doctors.
The methodological foundations of diagnostics are formed on the principles of the general theory of knowledge (epistemology), on methods of research and thinking common to all sciences. As a scientific method, diagnostics is based on the use of historically established knowledge, on observation and experience, comparison, classification of phenomena, revealing connections between them, constructing hypotheses and testing them. At the same time, diagnostics as a special area of epistemology and an independent section of medical knowledge has a number of specific features, the main one of which is determined by the fact that the object of research is a person with a particular complexity of functions, connections and interaction with the environment. A feature of diagnostics is also its connection with the general theory of pathology, therefore, historically, the development of diagnostics as a form of cognition was determined mainly by the refraction of general philosophical knowledge in specific issues of the development of medical theory, in ideas about health and disease, about the body, its connection with the environment and the relationship in it parts and the whole, in understanding causality and laws of development diseases.
In modern medicine, the theory of pathology is based on the principles of determinism, the dialectical unity of the organism and the environment (including its geographical, biological, environmental, social and other characteristics), the historical, evolutionary conditionality of the body's reactions to damage, especially adaptation reactions.
Methodologically, diagnostics also has a number of features. Firstly, the complexity of the object of study determines the existence in diagnostics of a diversity of research methods, rare for one science, both our own and borrowed from almost all branches of physics, chemistry, and biological sciences. This requires multilateral training of doctors and a special systematization of knowledge of the natural sciences, designed specifically to solve different options diagnostic tasks.
Secondly, unlike other sciences, where the object of study is recognized by significant and constant signs, in medicine the recognition of a disease is often based on insufficiently expressed, low-specific signs, and some of them often refer to the so-called subjective symptoms, which, although they reflect objective processes in the body also depend on the characteristics of the patient’s higher nervous activity and can be a source of diagnostic errors.
Thirdly, the diagnostic examination should not cause harm to the patient. Therefore, a direct and accurate, but potentially dangerous for the patient, method of diagnostic research is usually replaced in practice by a variety of indirect, less accurate diagnostic methods and techniques. As a result, the role of medical conclusions, the so-called clinical thinking, significantly increases in the diagnostic process.
Finally, the features of the diagnostic process are determined by the limited time and opportunities for examining a patient for conditions requiring emergency treatment. In this regard, the diagnostic experience of the doctor is of great importance, which determines the ability to quickly recognize the leading pathology in a given patient based on the similarity of a set of symptoms with those already observed by the doctor earlier and therefore having syndromic or even nosological specificity for the doctor, which, however, does not lend itself to abstract description. It is in this sense that we can talk about the role of so-called medical intuition in diagnosis.
The process of establishing a diagnosis of a disease during the initial examination of a patient includes analysis, systematization, and then generalization of the symptoms of the disease in the form of a nosological or syndromic diagnosis or in the form of constructing a diagnostic algorithm.
The definition of a disease as a nosological unit is the responsible and most important stage of diagnosis. Nosological approach Provides for establishing a diagnosis depending on the coincidence of the entire picture of the disease with known clinical manifestations typical of a certain nosological form (specific symptom complex), or on the presence of a symptom pathognomonic for it.
Syndromic diagnosis can be an important step towards disease diagnosis. But the same syndrome can be formed in different diseases under the influence of different causes, which characterizes syndromes as a reflection of a certain pathogenetic essence, as a result of a limited number of typical reactions of the body to damage. In this regard, a syndromic diagnosis has the advantage that, being established with the least amount of diagnostic research, it is at the same time sufficient to justify pathogenetic therapy or surgical intervention.
A diagnostic algorithm is a prescription for a sequence of elementary operations and actions to establish a diagnosis of any of the diseases manifested by a given set of symptoms or a given syndrome (see. Diagnostic algorithm). In its perfect form, the diagnostic algorithm is compiled for cybernetic diagnostic methods that involve the use of a computer (see. Cybernetics in medicine). However, explicitly or implicitly, the process of medical diagnosis is almost always algorithmized, because The path to a reliable diagnosis, even in the presence of highly specific (but not pathognomonic) symptoms, goes through an intermediate probable diagnosis, i.e. constructing a diagnostic hypothesis, and then testing it with data from a targeted additional examination of the patient. In the diagnostic process, the number of hypotheses should be reduced to a minimum (the principle of “economy of hypotheses”) in an effort to explain with one hypothesis as many existing facts (symptoms) as possible.
With the initial detection of only nonspecific symptoms, diagnostic assumptions in the nosological sense are impossible. At this stage, the diagnostic process consists of a general determination of the nature of the pathology, for example, whether there is an infectious disease or metabolic disease, an inflammatory process or neoplasm, allergy or endocrine pathology, etc. After this, a targeted diagnostic additional examination of the patient is prescribed to identify more specific signs or syndrome.
The construction of a diagnostic hypothesis based on symptoms is made by inductive inference, i.e. from knowledge of a lesser degree of generality (individual symptoms) to knowledge of a greater degree of generality (form of the disease). Hypothesis testing is carried out through deductive reasoning, i.e. from the generalization made back to the facts - to the symptoms and results of the examination undertaken to test the hypothesis. The deduction method makes it possible to detect previously unnoticed symptoms of the disease, to anticipate the appearance of new symptoms during the course of the disease, as well as its very development, i.e. determine the prognosis of the disease. Thus, in the diagnostic process, inductive and deductive methods necessarily complement each other.
Establishing a syndrome or a relatively specific set of symptoms is usually sufficient to construct several diagnostic hypotheses, each of which is tested in the process of differential diagnosis.
Differential diagnostics is based on the detection of differences between the manifestations of a given disease and the abstract clinical picture of each of the diseases in which the same or similar signs are possible. For differentiation, as many symptoms of each disease as possible are used, which increases the reliability of the conclusions. The exclusion of a suspected disease is based on one of three principles of differentiation. The first of these is the so-called principle of significant difference, according to which the observed case does not belong to the disease being compared, because does not contain a constant sign of this disease (for example, the absence of proteinuria excludes nephritis) or contains a symptom that has never occurred with it.
The second principle is exclusion by contrast: this case is not a supposed illness, because with it, a symptom that is directly opposite to what is observed is constantly encountered, for example, with achilia, duodenal ulcer is rejected, because it is characterized by gastric hypersecretion.
The third principle is to exclude a suspected disease based on differences in symptoms of the same order in quality, intensity, and characteristics of manifestations (the principle of non-matching symptoms). All these principles are not of absolute importance, because... The severity of certain symptoms is influenced by many factors, including the presence of concomitant diseases. Therefore, differential diagnosis involves additional testing of the diagnostic hypothesis, even if it seems to be the most reasonable of all hypotheses. The presumptive diagnosis is verified by the practice of subsequent therapeutic and diagnostic measures arising from it, as well as monitoring the dynamics of the disease.
The conclusion of the diagnostic process is the transition from an abstract-formal diagnosis of the disease to a specific diagnosis (diagnosis of the patient), which in its entirety represents the totality of anatomical, functional, etiological, pathogenetic, symptomatic, constitutional and social recognition, i.e. synthesis - establishing the unity of various aspects of a given patient’s condition, his individuality. The diagnosis of the patient does not have generally accepted formulations; in medical documents, a significant part of its content is reflected in the epicrisis. The diagnosis of the patient serves as the basis for individualizing treatment and carrying out preventive measures.
Bibliography: Vinokurov V.A. Analogy V diagnostic thinking of a doctor, Vestn. chir., t. 140, no. 1, p. 9. 1988; Leshchinsky L.A. and Dimov A.S. Is the concept of “diagnostic hypothesis” valid? Wedge. Med., t. 65, No. 11, p. 136, 1987; Makolkin V.I. The main causes of diagnostic errors in a therapeutic clinic, ibid., vol. 66, no. 8, p. 27, 1988; Popov A.S. and Kondratyev V.G. Essays on the methodology of clinical thinking. L., 1972, bibliogr.
philosophy medicine disease knowledge
A diagnosis in clinical medicine is a brief conclusion about the essence of the disease and the patient’s condition.
Diagnostics consists of three main sections: a) semiology - the study of symptoms; b) methods of diagnostic examination; c) methodological foundations defining the theory and methods of diagnosis (Postovit V.A., 1991)
Diagnosis is the main, core essence of clinical medicine. The diagnosis must be correct, detailed and early. The diagnosis is based on a nosological principle, including the name of a specific disease in accordance with the existing nomenclature. According to the method of constructing and justifying the diagnosis, two types are distinguished - direct and differential. The essence of the first (direct) is that the doctor, having collected all its typical, or pathognomonic, signs, considers them from the point of view of only one alleged disease. The essence of the differential diagnosis is that from a number of different diseases that have many common features, after establishing differences, one or another disease is excluded. Differential diagnosis consists of comparing this particular clinical picture with a number of other clinical pictures in order to identify one of them and exclude the rest.
A sign in the diagnosis of diseases can be “symptom”, “syndrome”, “symptom complex”, “clinical picture”. These signs vary in their specificity and degree of generality. A symptom is a single (specific or nonspecific) sign. Symptoms can be divided into obvious and hidden. The former are detected directly by the doctor’s senses, the latter - with the help of laboratory and instrumental research methods. A symptom complex is a nonspecific combination, a simple sum of symptoms. A syndrome is a specific combination of internally interconnected several symptoms. A specific symptom, symptom complex, syndrome refers to special signs. The clinical picture - the entire set of symptoms and symptom complexes - is a universal (classical) sign of the disease. However, signs of the disease in the classical general form, when all the symptoms and symptom complexes are present, are rarely found in reality. Therefore, a universal characteristic is revealed through individual characteristics and their special combinations.
Only in relatively rare cases, when a pathognomonic or highly specific symptom (symptom complex) is identified, is it possible to make a reliable nosological diagnosis. Much more often, the doctor deals with a patient’s totality of general, nonspecific symptoms and must spend significant effort analyzing them. At the same time, in diagnosis, symptoms should not be mechanically summed up, but interrelated, taking into account the significance of each of them.
Clinical experience shows that of the three sections of diagnosis, medical logic is the most important, since the constantly developing semiology and medical technology are of subordinate importance. For example, one type of inference is an analogy - about the similarities and differences between the symptoms of a particular patient with the symptoms of known diseases. More complex methods in the epistemological process are induction and deduction.
Induction is a research method that consists in the movement of thought from studying the particular to the formulation of general provisions, that is, diagnostic thinking moves from individual symptoms to establishing a nosological diagnosis. Deduction is an inference moving from knowledge of a greater degree of generality to knowledge of a lesser degree of generality. The logical structure of a clinical diagnosis is the key way to solve any diagnostic problem with a high degree of efficiency or get as close as possible to solving it. Even with insufficient erudition in matters of a related specialty, the doctor, using the logic of clinical thinking, will not pass by an unclear phenomenon, but will try using the techniques of diagnostic logic and attraction at each logical stage necessary information to find out the pathological essence of the disease and the extent of its danger for the patient.
The movement of knowledge in the diagnostic process goes through a number of stages, reflecting the analytical and synthetic activities of the doctor. Thus, according to V.P. Kaznachayev and A.D. Kuimov, the entire logical structure of making a clinical diagnosis after direct (empirical) perception of the patient as a specific identity can be divided into 5 stages:
The first stage (first degree of abstraction): clarification of the anatomical substrate of the disease, that is, its localization in the body.
Second stage (second degree of abstraction): clarification of the pathoanatomical and pathophysiological nature of the pathological process.
Third stage (highest degree of abstraction): formation of a working diagnostic (nosological, less often syndromic) hypothesis.
Fourth stage: determining the degree of probability of the diagnostic hypothesis through differential diagnosis.
The fifth stage (synthetic, return from an abstract diagnosis to a concrete one): clarification of etiology and pathogenesis, formulation of a clinical diagnosis taking into account all the features of the disease, drawing up a treatment plan, determining the prognosis of the disease, subsequent testing of the diagnostic hypothesis in the process of examination, observation and treatment of the patient.
In V.A. Postovit’s diagram of the diagnostic process, three phases are identified:
1. Identification of all symptoms of the disease, including negative symptoms, during clinical and laboratory examination. This is the phase of collecting information about the morbidity of a particular patient;
2. Understanding the detected symptoms, “sorting” them, assessing them according to their degree of importance and specificity, and comparing them with the symptoms of known diseases. This is the phase of analysis and differentiation;
3. Formulating a diagnosis of the disease based on the identified signs, combining them into a logical whole - the phase of integration and synthesis.
However, the division of the diagnostic process into separate stages is conditional, because in real diagnostics it is impossible to draw a line between the stages of this process, to determine exactly where one ends and the second begins. In real life, the diagnostic process is continuous, strictly limited in time, and there are no clearly defined periods or sequential transitions of the thought process in it, so the doctor classifies symptoms continuously, during the examination of the patient.
Clinical thinking is a specific mental conscious and subconscious activity of a doctor, which makes it possible to most effectively use the data of science, logic and experience to solve diagnostic and therapeutic problems in relation to a particular patient. The main forms of clinical thinking are carried out through analysis and synthesis.
In diagnostic work there are a lot of guesses - so-called hypotheses, so the doctor is obliged to constantly think and reflect, taking into account not only indisputable, but also difficult-to-explain phenomena. A preliminary diagnosis is almost always a more or less probable hypothesis.
According to E.I. Chazov, the success of a doctor’s professional diagnostic activity is ultimately determined by the logical and methodological capabilities of his medical thinking.
The need for doctors to know logic is especially increasing today, because it is becoming obvious that a significant part of diagnostic errors are not so much the result of insufficient medical qualifications, but rather an almost inevitable consequence of ignorance and violation of the most elementary laws of logic. These laws for any type of thinking, including medical thinking, have a normative nature, since they reflect the objective certainty, differences and conditionality of the phenomena of the material world.
The basic rules of logically coherent medical thinking are revealed in the four laws of logic - the laws of inferential knowledge. The law of identity characterizes the certainty of thinking.
The consistency of thinking is determined by the law of non-contradiction and the law of excluded middle. Evidence-based thinking is characterized by the law of sufficient reason.
The requirements of the logical law - the law of identity - are that the concept of the subject of research (for example, a symptom, nosological unit, etc.) must be precisely defined and maintain its uniqueness at all stages of the thought process. The law of identity is expressed by the formula: “ And there is A.” At the same time, any dynamic or relatively stable object (process, sign of a process) can be thought of as A, as long as during reflection, the once taken content of the thought about the object remains constant. In diagnostic practice, compliance with the law of identity requires, first of all, specificity and definiteness of concepts. The substitution of a concept, a thesis that reflects the phenomenon under discussion in its essential principles is a frequent cause of fruitless discussions among specialists of various profiles. The importance of the law of identity in diagnostic work is constantly increasing. With the development of medical science, not only the names of many diseases are clarified, their varieties are discovered, new means of examining the patient appear, and, along with them, additional diagnostic signs. The content of concepts used in diagnosis (symptoms, syndromes, nosological units) often changes significantly. Changes in environmental conditions and the pace of human activity give rise to diseases that were not previously encountered. The law of identity requires constant updating and clarification of the international and national nomenclature of nosological forms, classifications of diseases and their use in everyday diagnostic work by a doctor of any specialty.
The law of non-contradiction requires consistency in reasoning, the elimination of contradictory, mutually exclusive concepts and assessments of phenomena. This law is expressed by the formula: “the propositions A is B” and “A is not B” cannot be simultaneously true. A violation of the law of contradiction is manifested in the fact that a true thought is affirmed simultaneously and on an equal basis with the thought opposite to it. More often this occurs when the conclusion about the essence of the disease is based on an analysis of nonspecific symptoms and the doctor has not taken proper measures to identify the pathognomonic signs of the nosological form. A similar situation arises in cases where the diagnostic hypothesis is based on part of the clinical symptoms and other signs of the disease that contradict the expressed judgment are not taken into account. Formal-logical contradictions cannot be confused with dialectical contradictions in objective reality and knowledge.
The law of exclusion of the third, which follows from the law of non-contradiction, is expressed by the formula: “A is either B or not B.” This law states that two contradictory statements about the same subject at the same time and relative to each other cannot be true and false together. In this case, out of two judgments, one is chosen - the true one, since there is no third intermediate judgment, which must also be true. For example, pneumonia in certain conditions can be either the main disease that led the patient to death, or only a complication of other diseases.
The logical law of sufficient reason is expressed in the formula: “if there is B, that is, as its basis A.” The law states that every reason must have a sufficient reason to be true. The validity of the diagnosis is based on the establishment of symptoms and syndromes specific to a given nosological form, which in turn must also be justified. To substantiate the diagnosis, the practice-tested truths of modern medical science are used. The most reliable diagnosis will be made by a doctor who constantly uses the latest achievements of practical and theoretical medicine. Violation of the law of sufficient reason continues to be a source of contradictions in some modern ideas about the pathogenesis of a number of diseases, as well as difficulties associated with the reproducibility of the same clinical and pathological diagnosis by different specialists.
Practical verification of the truth of the diagnosis is a difficult problem at present. In this regard, judgment about the correctness of the diagnosis based on the effectiveness of treatment of patients is of relative importance, since treatment may be independent of the diagnosis in cases where the disease is recognized but poorly treated, or the condition of patients worsens due to an unclear diagnosis. In addition, pathogenetic therapy may be effective at certain stages of a large group of diseases that have different etiologies, but some general mechanisms development. Nevertheless, in terms of observations even now, this method of verifying the truth of the diagnosis can have a positive effect.
Much more often, the following two methods are used to identify diagnostic errors (the truth of a clinical diagnosis):
1) studying the degree of agreement between the diagnoses of some medical institutions (clinics) and the diagnoses of other institutions (inpatient departments of hospitals) - an indirect verification of the truth of the diagnosis;
2) comparison of clinical and pathological diagnoses according to a number of parameters determined by the relevant methodological developments- direct verification of the truth of the diagnosis.
However, it should be taken into account that the effectiveness of clinical and pathological comparisons (not only in autopsies and subsequent clinical and anatomical conferences, but also on surgical and biopsy materials) depends on a number of objective and subjective factors, primarily determined by the material and technical equipment of the departments of the pathological service , the professionalism of the pathologist and the attending physician, the degree of their cooperation in the complex work of identifying the essence of suffering, the cause and mechanism of death of the patient.
Nosological form (nosological unit) is a specific disease that is distinguished as an independent disease, as a rule, on the basis of established causes, development mechanisms and characteristic clinical and morphological manifestations.
Also, in modern medicine, antinosology is widespread, which states that only sick people exist, but there are no diseases.
Thus, we can conclude that an important supporting part of a clinical diagnosis is knowledge of semiology and the ability to think logically. At the same time, the supporting parts of the diagnosis are the conscious clinical experience of the doctor, as well as his intuitive, specific thinking.
When starting to study diagnostics, doctors approach a sick person for the first time and thus enter the field of practical medicine. This is a very difficult and unique activity. " Medicine as a science ", according to S. P. Botkin, " provides a certain amount of knowledge, but knowledge itself does not yet provide the ability to apply it in practical life" This skill is acquired only by experience.
Practical, or clinical, medicine must be considered as a special science, with special methods inherent in it. Diagnostics as a special discipline deals with the methodological side of clinical medicine.
Observation, assessment of observed phenomena and inference - these are the three mandatory stages on the path to recognizing diseases and making a diagnosis. According to these three stages, the entire content of diagnostics can be divided into three, to a certain extent, independent sections:
1) a department that includes methods of observation or research - medical technology or diagnostics in the narrow sense of the word;
2) a department devoted to the study of symptoms revealed by research - semiology or semiotics;
3) the department in which the peculiarities of thinking are clarified when constructing diagnostic conclusions based on observation data - medical or clinical logic.
The first two sections have now been developed in detail and constitute the main content of all diagnostic manuals and courses. The third department - medical logic - has not yet been theoretically developed in detail: usually in textbooks, in chapters devoted to the particular diagnosis of individual diseases, one can find only simple comparisons or listings of symptoms, only external milestones of medical logic. The assimilation of this essential and necessary aspect of the matter occurs in the clinic, in the very process of medical practice.
In order to fully appreciate and understand the current state of diagnostics, it is necessary to trace, at least in the most general terms, the course of its historical development in connection with the history of medicine in general.
We will dwell only on a few of the most important stages of this historical path.
It has become a well-known tradition to begin the history of medical issues with the “father of medicine” Hippocrates. This tradition has both objective and subjective justification. Objectively in the works of Hippocrates in the V-IV centuries. BC, humanity for the first time received a systematization of its centuries-old experience in the matter of healing. Subjectively, even now, 2500 years later, one can be amazed at the greatness of this man as a thinker and doctor. Having gathered together contemporary medical knowledge and experience, Hippocrates treated them critically and discarded everything that corresponded to direct observations, for example, all religious medicine of that time. Careful observation and facts were laid by Hippocrates as the foundation of medicine, and on this solid ground we see the further progressive development of medicine over the course of the 7th and 8th centuries until the 4th century. AD.
Diagnosis in the era of Hippocrates and his followers, in accordance with the general direction of medical thought, was based on careful observation of the patient. Great attention was paid to the patient's complaints and previous history of the disease; an accurate and detailed examination of the patient’s body was required, paying attention to general view, facial expression, body position, chest shape, condition of the abdomen, skin and mucous membranes, tongue, body temperature (by palpating with the hand); sleep, breathing, digestion, pulse and various types of secretions (sweat, urine, feces, sputum, etc.) were assessed.
As for the methods of objective examination of the patient, even then, apparently, all those methods were used that still form the basis of the practical doctor’s methodology, namely: palpation, for example, of the liver and spleen, changes in which were monitored even day by day; tapping - at least when determining the tympanic sound; auscultation (at least Hippocrates already speaks about the friction noise during pleurisy, comparing it with the sound of skin rubbing, and about sounds reminiscent of “boiling vinegar”, probably corresponding to fine wheezing, and the doctor Aretaeus in the 1st century AD absolutely definitely refers to a heart murmur); finally, shaking, the famous succussio Hyppocratis, which, along with fades Hyppocratis, is included in all diagnostic manuals. Thus, Hippocratic diagnosis, based on questioning the patient and on a detailed study of him using various senses, seems to be basically no different from modern diagnosis, but the difference between them, due to the subsequent improvement of research techniques, the development of semiotics and understanding of the essence of symptoms, of course, colossal.
In the II-III century. AD, a revolution took place in the field of medical thought, which had a tremendous impact on the entire further development of medicine. The reason for this revolution can be considered the scarcity of accurate natural historical knowledge of that time, the already revealed inconsistency with the requirements of practical medicine and the inability for them to give more or less satisfactory answers to questions arising at the patient’s bedside. The searching thought, not finding explanations in observations and facts, took a different path - the path of speculative reasoning. And Galen - the second monumental figure in the history of medicine after Hippocrates, who, as it were, concentrated in himself all the knowledge of his contemporary era and presented it in 434 trends - went towards this new direction of medical thought. He brought all the medical knowledge of that time into one complete system, in which all the gaps of factual knowledge were filled with abstract reasoning so that there was no room for any doubts or searches.
Diagnostics at this time still remained fundamentally Hippocratic and was enriched by a detailed study of the pulse and the invention of mirrors to illuminate some of the more accessible body cavities (rectum, vagina). At the same time, thanks to Galen, the foundation of topical diagnostics is laid, i.e., recognition of local foci of diseases. Before that, according to the pathogenetic ideas of the ancients, disease was considered as a general suffering, as diathesis or dyscrasia, depending on changes in the basic juices of the body.
Next comes the era of the Middle Ages. In the field of medical thought, this is the era of the undivided dominance of Galen's ideas. His teaching, as a dogma, is not subject to doubt or challenge. For more than 1000 years, free creative thought has died down, stagnation sets in and the regression inevitably associated with it. Diagnosis in this dark and sad era has lost its vital reality and has been reduced almost exclusively to examining the pulse and examining urine.
The Renaissance gives impetus to the liberation of human thought from the oppression of metaphysics. In the 16th and 17th centuries. the inductive, natural-scientific method of thinking and research lays the foundation for modern scientific medicine (Vesalius is the “Luther of anatomy”; Harvey is the founder of circulatory physiology; Morgagni is the founder of the organo-localistic direction in pathological anatomy and medicine). But the deductive method of thinking did not give up its positions without a fight, the struggle with varying success continued until the first third of the 19th century, when natural philosophy - the last medical speculative system - had to finally give way to modern medicine, which stood on the solid ground of natural science.
In diagnostics during this period of time, until the beginning of the 19th century, there was no noticeable movement forward; even if we take into account some advances in the recognition of heart diseases (palpation of the cardiac region, examination of the jugular veins and carotid veins) and the introduction of chemical testing of urine.
G early 19th century Medicine has entered a period of its development, which we are witnessing. An unshakable natural scientific foundation provides the opportunity and guarantee of continuous movement forward, and this movement occurs at an ever-increasing speed, changing the entire face of medicine beyond recognition almost before our eyes.
Scientific Basics modern methods diagnostics, based mainly on the development of physics and chemistry, began to be founded at the beginning of the 18th century, but the thermometer (Fahrenheit - 1723, Celsius - 1744), ear mirror ( artificial lighting eardrum - 1741) and percussion (Auenbrugijer, 1761) were not found suitable soil for distribution and did not meet with sympathy. And only from the beginning of the 19th century. diagnostics began to flourish rapidly: in 1808, almost half a century after the invention of percussion by Auenbrugger, French translation his work, which has already attracted everyone's attention; in 1818 Corvisart published his observations on percussion; in 1819 Laennec published his work on auscultation; in 1839 Skoda gives scientific justification for these methods of physical diagnosis. Chemical and microscopic research methods are being developed. In the middle of the 19th century. Clinical thermometry is being developed.
Great contribution to the diagnosis of internal diseases contributed by Russian and Soviet doctors and scientists. The activities of the founders and reformers of the modern Russian therapeutic clinic - S. P. Botkin, G. A. Zakharyin and A. A. Ostroumov (second half of the 19th century), who paved those main paths and pointed out that functional-physiological direction, along which to a large extent the development of the Soviet clinic is still going on. In particular, Botkin, having raised the methodology of clinical research to a greater scientific height, substantiated individualizing diagnostics - diagnosing not the disease, but the patient. Zakharyin developed and brought anamnesis, as a method of examining a patient, to the level of real art. Ostroumov, relying on the evolutionary principle and the laws of heredity, developed essentially constitutional clinical diagnostics. If percussion and auscultation were adopted by us, one might say, in a ready-made form, then palpation, as a research method, was subject to the most detailed development and received its most complete form in our country from V.P. Obraztsov (Kyiv) and his school (the so-called systematic methodical deep sliding palpation). In Russian and Soviet clinics, many different and important methods and methods of private diagnostics have been developed. Some of them have received worldwide recognition and widespread distribution. These are, for example, the Korotkov auscultatory method for determining arterial blood pressure and the Arinkin method of sternal puncture of bone marrow.
Extensive pathological and anatomical control of the diagnosis (Rokitansky, Virchow) gives the diagnosis of internal diseases the opportunity for further confident development. In our Union, this was especially facilitated by the method of comprehensive examination of organs during autopsy of corpses (mainly the method of complete evisceration developed by G.V. Shor), the mandatory autopsy of all dead in medical institutions and the widespread dissemination of clinical-anatomical conferences over the past 15-20 years ( A. I. Abrikosov, I. V. Davydovsky, S. S. Weil, V. G. Garshi, the development of medicine over the past 50 years has not taken on a particularly rapid pace and wide scope. It is based on the colossal successes of natural science in general, physics, and chemistry. and biology in particular, new scientific disciplines arose, developed and differentiated, such as bacteriology, serology, the study of immunity, protozoology, epidemiology, physical and colloid chemistry, enzymology, radiology, hematology and many others.
Diagnostics, widely using and adapting for its purposes the latest research methods in the field of natural science, currently has a large number of microscopic, physical, chemical, physicochemical, bacteriological and biological laboratory research methods.
The microscopic (or histological) method, thanks to the improvement of the microscope and staining methods, has reached a high degree of perfection and makes it possible to study the morphological composition of various compartments and secretions, physiological and pathological, body fluids, as well as study various tissues by biopsy. Blood microscopy has developed into a special hematological research method, playing a prominent role in the diagnosis of a number of different diseases. The study of cellular elements of body fluids has developed into a cytological method or cytodiagnostics. Introduction of microscopy to dark field, the so-called ultramicroscopy, allows us to penetrate with our gaze beyond the limits of microscopic visibility.
Physical methods in modern diagnostics are very widely represented by various kinds of measuring, recording, optical and electrical appliances. I will point out only some areas of application of these methods: measurement of blood pressure, graphic recordings of heart contractions, arterial and venous pulses, photographic recordings of heart sounds and noises - the so-called phonography - and electrical currents of the heart - electrocardiography.
Over the 50 years of its existence, the X-ray method of research has developed into an independent discipline, and X-ray diagnostics in the form of fluoroscopy, radiography, and X-ray cinematography has miraculously enhanced our vision, and we now see with our own eyes the true size of the heart and its movements, the condition of the blood vessels, the activity of the stomach, the relief its mucosa, stones in the kidneys or gall bladder, the location and nature of pathological changes in the lungs, tumors in the brain, etc.
Chemical methods, when applied to the study of urine, the contents of the gastrointestinal canal, blood, etc., reveal to us the secrets of intracellular metabolism and allow us to monitor the function of various organs.
Physicochemical methods based on the molecular and colloidal properties of body fluids are becoming increasingly important in connection with the development of physical chemistry.
The bacteriological method in the form of bacterioscopy and the culture method plays an extremely important role for the etiological diagnosis of infectious diseases.
Biological methods in the form of various immune reactions (immunodiagnostics) are widely used: the agglutination reaction (Gruber-Widal) for the recognition of typhoid fever, paratyphoid fever, typhus, cholera, dysentery, etc.; complement fixation reaction (Bordet - Gengou) - for syphilis (Wassermann), echinococcus (Weinberg), tuberculosis (Bezredka); tuberculin reactions - subcutaneous, skin, ocular, etc. This also includes the isohemoagglutination reaction (determination of blood groups), which is of great practical importance, etc.
This, in the most general terms, is the modern diagnostic equipment using scientific laboratory research methods.
All these methods are characterized by the fact that they are based on visual perceptions, as in other exact sciences. However, the main feature of medical diagnosis is that it is not limited to methods based only on visual perceptions, but also uses all other senses, increasingly equipping them with instrumental technology.
The persistent desire to use all our senses for the purpose of research constitutes the first characteristic feature diagnostics and is explained by the extreme complexity of its object - a sick person: this is the most complex biological organism, which is also in a period of illness in particularly difficult living conditions.
However, not all of our senses are equally good analyzers of external phenomena. The thinner the analyzer, the more reliable the data obtained through it, the more correct the conclusion based on it, the closer, therefore, to reality is our diagnosis. And vice versa, the rougher the analyzer, the less reliable the observation, the greater the possibility of error. Therefore, diagnostics, forced by necessity to use all methods of observation available to it, thereby weakens the power of its conclusions.
Two factors determine the dignity of our senses as analyzers of the external world:
1) the lowest threshold of irritation, i.e. that minimal external irritation that is already capable of causing sensation, and
2) the difference threshold of irritation, i.e. that minimal change in the degree of irritation, which we have already noted as a difference. The lower both thresholds of irritation are, the more accurate the analyzer is. From this point of view, our senses are arranged in the following descending order: vision, touch (in connection with active motor sensations), hearing, smell and taste.
Thus, the data we obtain using vision is the most accurate and reliable. Feeling, which is a combination of touch and active motor sensations, is the second most accurate research method, since the difference threshold here can reach a very small value. The organ of hearing as an analyzer is much lower than the first two. Therefore, percussion and auscultation as research methods are far inferior to inspection and palpation, and the data obtained with their help leaves much to be desired in terms of clarity and accuracy. This ambiguity of perception is a constant source of error. Hence the desire to replace auditory perceptions with visual ones whenever possible is understandable. And diagnostics in this regard has already achieved relatively much.
Of extremely important practical importance is the fact that all our senses are capable of training, of a certain education and improvement through systematic exercise.
A characteristic feature of medical diagnosis from a methodological point of view is a unique, exclusively characteristic method of research by questioning the patient (history): In this way, we strive to find out the patient’s complaints, his past, his mental state and his individuality. This method in practice presents a number of difficulties, and the ability to collect an anamnesis must be learned no less than the ability to objectively examine, especially since the correct collection of an anamnesis is undoubtedly more difficult to learn than the method of objective examination.
Further, a characteristic property of diagnostics is the need to individualize each patient, that is, to capture, understand and evaluate the unique combination of physical and mental, physiological and pathological characteristics that a given patient has at the moment represents.
Modern diagnostics, fully equipped with all its research methods, has powerful analytical power, but it also faces tasks of a synthetic order: assessing the condition and activity of individual organs, their systems and the entire organism as a whole. To do this, it is necessary to combine a number of individual symptoms into one general picture. Functional diagnostics strives for this task, which, however, in relation to most organs and systems is still in the development period; it is most developed in relation to the gastrointestinal tract and kidneys, less - to the cardiovascular system and liver and is almost only outlined in relation to other body systems (hematopoietic organs, vegetative nervous system, endocrine glands).
Finally, in recent years, diagnosis has been faced with more and more urgency and in a new, broader light, by the task of recognizing and assessing the mental state and inner life every patient. For at present there is no longer any doubt that the neuropsychic factor, especially affective-emotional experiences of a depressive nature, are of great importance for the occurrence, course and outcome of almost all diseases. Consequently, there is a need to develop methods of elementary psychological and psychopathological analysis for the needs of everyday medical research in all areas of practical medicine. Thus, a new and important component is outlined in the general course of the recognition process - the diagnosis of the patient’s personality and the assessment of her reaction.
These are the past, present and possibly the near future of diagnostics, these are its features as the methodological basis of practical medicine. Medicine is closely related to other areas of scientific knowledge. The total amount of knowledge is growing at an enormous rate. Research methods are multiplying and becoming more complex. Almost each of them, taken in its entirety, is able to absorb all the attention and time of the person studying it, and yet all diagnostics with all its many methods is only one of the stages of a doctor’s activity at the patient’s bedside and only one of the many disciplines of the course of medical Sci.
The abundance of the actual stock of scientific knowledge needed by a doctor, the ever-increasing speed of its accumulation, the constant enrichment and complication of research methods and techniques and the peculiar difficulties of their practical application at the patient’s bedside - all this makes you think seriously about the task of studying and mastering all this material in general and diagnostics in particular.
The demands placed on medical school today are extremely high. A Soviet doctor must be fully armed with advanced medical theory and modern medical technology, because nowhere and never is the task of providing every citizen with highly qualified medical care was not raised or permitted in the same way as it is currently in the USSR. The task of a medical school should be seen as providing the future doctor with the necessary general medical training, good medical technique, modern scientific methods and strong skills for independent work, with the help of which he could further specialize and improve in any field of medicine and keep up from its constant forward movement.
Diagnostics - the subject is purely methodological; its content consists of various research methods. Not even the most detailed and clear presentation of research methods from the department can fully teach diagnostics. All methods are based on the perceptions of one or another of the sense organs, and in diagnosis, as already mentioned, almost all senses at the same time. This circumstance explains the difficulties that diagnosis presents. Only through repeated, long-term and independent exercises can one properly educate one’s senses and one can master the ability to observe and explore. This explains why an experienced doctor sees, hears and touches what an inexperienced doctor does not notice at all. But the same is true for medical thinking, which is also developed through constant exercise, through active independent work. The law according to which the development of the individual repeats the development of the species has a general meaning: it also applies to education. To become a scientist or a doctor, you need to go through the entire path of human thought and experience in this regard in an abbreviated form and at an accelerated pace: you need to learn to observe, notice the general in particular, generally grasp the individual, see the pattern in the change of phenomena, etc. Active and independent work in one area and with one method, like any training in a certain direction, makes it extremely easier in the future to master other methods and work in other areas.
So, practical medicine in general, and diagnostics as its methodological basis in particular, due to their inherent characteristics, require a special approach to their study and assimilation. Here, more than anywhere else, the proposition is true that the essence of education always lies in self-education.
Only through truly independent work, through constant education of your organs of perception, through persistent active thinking can you master the technique, but once you master it, it is no longer difficult to acquire the necessary knowledge and experience.
Of course, the most important and decisive prerequisite for the most successful and skillful use of modern methods of medical diagnosis is mastery of the basic method of understanding life as a dialectical process - dialectical materialism. Only with the help of this method is that in-depth analysis and subsequent synthesis of the complex interaction of biological and social factors possible, which makes it possible to establish a correct individual diagnosis and apply effective therapy.