Patient Safety

The Relevance of Logic in Medical Care

Alexander L. Gungov, Tatiana Tzarvulanova

• Publisher: Ibidem Press
• Year: 2018
• ISBN:
  9783838272139
• Topic: Philosophy
• Subtopic: Ethics & Moral Philosophy

In our time of well-publicized health care travails, in the U.S. and the UK and elsewhere, matters of financing too often subsume the dimension of patient care. In his latest book, Alexander L. Gungov studies a vital but neglected aspect of patient safety. Of the thousands of medical errors committed on a daily basis, in the bulk of unfortunate clinical decisions, a significant share pertains to various logical flows and epistemological fallacies. By focusing on the logical dimensions of clinical medicine, Gungov promotes awareness of the logical and epistemological traps that lie in the day-to-day care of patients.

Such a focus not only allows us to avoid falling into them, but demonstrates the practical value of looking at medicine from a new philosophical perspective. That perspective involves a broad and unusual collection of philosophers. The discussion takes its starting point from J. S. Mill's inductive methods and Giambattista Vico's verum-factum principle, but then sets out a unique combination of Charles Sanders Peirce's abductive reasoning, Immanuel Kant's reflective judgment, as well as G. W. F. Hegel's and D. P. Verene's speculative thinking, all marshalled to present a novel philosophical account of clinical diagnostics. Interpretation of practical examples elucidate the logical aspect of medical errors and suggests strategies of overcoming them. The book as a whole demonstrates the value of Hans-Georg Gadamer's hermeneutical insights into the enigmatic character of health.

This much-needed book will be of interest to medical practitioners, health policy makers, patients and their families, and advanced students and scholars in medicine, the medical humanities, medical epistemology, and the philosophy of medicine in general.

II.
Abduction-Based Diagnostics

1. Logical framework of diagnostics

Giving a correct diagnosis is undoubtedly an art. This, however, does not exclude the usage of logic in diagnostics. Moreover, it turns out that for a comprehensive study of the process of diagnostics, it is necessary to pass through the ontological and epistemological levels of consideration. According to the renowned expert in logic of medicine Edmund A. Murphy, we must distinguish between two ontological layers: (1) the taxonomical one, i.е., the ways in which health issues are grouped, and (2) the distinction of health states from health disorders and the categorization of health disorders, that is, nosology, where the concrete diagnostic units are specified. Besides, he also determines a third, epistemological layer, where the strategy of the diagnostics process or, more precisely, the basic aims of this procedure should be discussed in the first place; also included here are tasks of a logical character (according to Murphy’s definition), where the ways of usage of the facts gathered in reaching the diagnosis are considered, and finally, tactics, occupied with the specific methods of establishing the diagnosis.1 In our study, we will aim to show that the most serious logical difficulties appear precisely during the stage of the tactical tasks.

The taxonomization of diseases turns out to be a complex process in which classification is just one of the various approaches. It is accompanied by multidimensional analysis and by the cataloguing of particular cases. Diagnosis classification follows a number of principles, as is inherent to every classification, which gives them their specifics. These are naturalness, completeness, and segregation of the sections, i.е., a case should not fall into more than one class, as well as the usefulness of the classification. The latter principle divides into at least five subprinciples: “1. The identification of the basic mechanisms of the disease (these, in the case of tuberculosis, hemoglobinopathies, and so on, are identified); 2. The description of features (a way characteristic of the presentation of the syndromes, many skin diseases, and most heart diseases); 3. The enumeration of the effective means of treating or controlling the disease (such as arthritis, asthma); 4. The specific prognosis (as in leukemia, multiple sclerosis); and 5. The convenience of various institutions, such as hospital administration, the legal system, and education (mental deficiency, blindness).”2 In the series of taxonomic principles, there follows the explanatory ability of a given classification, its simplicity and constructiveness, which shows that an easy way exists to avoid confusion in the distribution of the diseases into relevant classes.3

Multidimensional analysis does not rely on classes, but uses formulas for the organization of available data. Such is the popular formula of calculation of the average value of systolic blood pressure На=100+Y,4 where На is 100 mm Hg and Y is the age of the patient, or the formula of the desirable weight W in kg, which should be equal to the height H in cm minus 100: W=H-100.

The main task in cataloguing particular cases of physical or mental suffering is to avoid putting the patient in some universal scheme, and to rather make inferences from the individual case of the patient while using all the possible knowledge that could assist the clinician in the clarification of a given case. In these circumstances, taxonomy is based on all facts contained in the record of the case, but not all facts accessible to science. In such an approach, the danger of treating the disease instead of the patient is overcome, but one can fall into the other extreme, inherent in psychiatry to the highest extent: to accept that “the only appropriate diagnosis is the name of the patient.”5

On the whole, one can approach the disease from three different perspectives: 1. When the efforts of an organism are directed to the preservation and support of a normal inner environment independently of the outer changes, this means that the disease is intertwined with homeostasis. This is especially the case with food poisoning: the diarrhea and vomiting to which poisoning leads are symptoms of the disease as well as signs of the organism striving to release the toxins swallowed. The therapy is directed to support the process of homeostasis. 2. Intrusion of the values of homeostasis, which are believed to differ significantly from the ones accepted as optimal. An example for this is hypertension and the resistance of the organism on the basis of the principles of homeostasis. Clinical intervention in this case aims at changing and resetting the mechanisms of homeostasis. 3. A completely chaotic state, presenting an entire mismatch of the welfare of the organism. Examples of such states are malignant tumors and autoimmune diseases. The only therapeutic method in such circumstances is to defuse the chaotic system.6

In defining the strategy of diagnostics (which, according to Murphy’s classification, is a transition from ontology to epistemology), two basic aims are identified depending on the type of the disease: а) to classify what lends itself to classification, and b) to measure what can be measured.7 A similar approach principally divides diseases into two different groups. The health disorders from the first group can easily and adequately find a place within a particular diagnostics class. Such are, for example, sickle cell anemia, Down’s syndrome, or muscular dystrophy. For them, precise nosological units are appropriate. They are grasped either almost like in medieval conceptualism as created by the national health organizations or respectively by the World Health Organization (WHО) or even as being naturally present in the realm of diseases in the spirit of medieval realism, which ascribes actual being to universals. Unlike these first types of health disorders, those that are related to the second group cannot be so easily located in a specific diagnostics category. Among them are diabetes, hypertension, and cases of obesity that have become a pathology. In these types of diseases, in order that they be adequately diagnosed, the established values would rather serve as an exact description of the diagnosis. Such an approach has a tendency toward nominalism, which in the name of precision and individuality could lose sight of the whole. Following this formulation, one would not specify “a diabetic with hypertension and obesity,” but a patient with data “9, 125 and 52,”8 corresponding to fasting blood glucose in mmol/l, to diastolic blood pressure in mm Hg and to weight in kilograms.9

What Murphy means by “logic of the diagnostics process,” in the narrow sense of the expression, includes several elements, the most important of which are the evaluation of the results of research and the sensitivity and the specificity of a given diagnosis. In the evaluation of the results with a view to making a diagnosis, a difficulty arises because given characteristics, serving as ground of the diagnosis, can exist among healthy people and people with pathological abnormalities as well. The difference between disease and a normal state would consist in the different degree of presence of the characteristics in question. In this case, the diagnostics of a certain disease would depend on the smaller or larger probability. There are undoubtedly many cases when a decision must be made in the dual system of either/or and, furthermore, by examining the conjunction “either” strictly as an exclusive disjunction—for example, to operate on the patient or not, or to begin a therapy with serious side effects or not, etc.10

When the question of the sensitivity and specificity of diagnosis11 is discussed, the attention is focused mainly on discerning faulty ascription of a disease (false positive results) and the wrong exclusion of diseases (false negative results). Depending on the significance and specificity of the disease diagnosed, the errors in one of these two directions can be grasped as more dangerous than the other. If the wrong assertion of tuberculosis is discussed, one must bear in mind that this disease poses a serious life threat if it is left untreated. Besides, the longer it remains undiagnosed and untreated, the more serious the complications it can lead to, such as malformations of the affected organs (e.g., the lungs or the kidneys). It is also important that this is a kind of diagnosis in which, thanks to contemporary therapeutics, a very high percentage of healing is achieved, or more precisely, damage to the affected organs is halted. What is more, tuberculosis (TB) is an infectious disease which is yet another strong reason in favor of its early diagnosis and treatment. This means that in the case given, the efforts must be directed towards allowing the fewest possible false negative results, which presupposes the avoidance of too-stern criteria for diagnostics. In these circumstances, the looser criteria of diagnostics, which potentially lead to false positive results, would inflict considerably less damage than the unjustified strict criteria, allowing for a large number of false negative results.12

The approach taken in the diagnosis of syphilis should be comparable to the approach described above. It is true that the unnecessary treatment in false positive results here entails certain risks because some people do not tolerate the treatment. The material costs for unnecessary treatment are also not negligible. But, in general, the negative results from the unnecessary treatment are negligible, whereas in a false negative result, where treatment is not undertaken, the consequences could be dramatic due to the complications in the patient as well as to the real possibility of infecting other people. By the same token, relatively relaxed criteria for diagnostics are recommended in the example of syphilis, and when doubt arises over whether the disease is present or there is just a false positive result, the most prudent behavior would be to conduct a treatment. In other diseases that can lead to serious consequences if not treated, such as amebic dysentery, the beginning of the treatment is more arbitrary, unlike in s...

Table of contents

• Table of Contents
• Acknowledgments
• Preface
• Introduction: Wonders and Impressions
• I. Vichian Perspective on Pathogenesis and Therapy
• II. Abduction-Based Diagnostics
• III. Logical Errors in the Clinical Discourse
• Conclusion: Patient Safety in Terms of Logic and Philosophical Interpretation
• Works Cited
• SMP Studies in Medical Philosophy
• Copyright