Prognosis

PROGNOSIS (from the Greek prognosis - knowledge beforehand, prediction), prediction of the course of a disease. Prediction can be stated in general terms and concern only the outcome of the disease (life-death, incomplete and complete recovery - prognosis quoad vitam and quoad valetudinem completam), but one can also predict details: the occurrence of improvements and deteriorations, the effect of the disease on working capacity and general condition, etc. Analysis of prognostic judgments shows that for prediction, the correct diagnosis of the disease is of primary importance. For many diseases, prognosis follows directly from recognition, especially in severe cases. Establishing the presence of widespread cancer makes the prognosis quite certain. On the other hand, a runny nose or a slight scratch allow one to foresee a favorable course of the disease. However, it is not difficult to notice that even in such a primitive form, prognostic reasoning has many vulnerable points, despite the undoubtedly correct diagnosis. In the first example, the statement that advanced cancers are fatal, in rare cases, with successful surgery, allows for exceptions. Turning to the second example, one cannot fail to take into account that any runny nose, even the mildest, can lead to complications, and then the prognosis will change depending on this complication. Therefore, without even mentioning that the absence of complications at the time of prognosis must be established, the conclusion about the safety of a patient's runny nose requires qualification. The examples given are chosen from areas where exceptions are so rare that practically no doubts arise. Both predictions are based on repeated observations, the results of which could be brought into statistical form (number of recovered: number of sick) or, as unprocessed statistical material, have remained in the physician's memory (medical experience). Analysis of a more complex case reveals the impossibility of always speaking with such certainty as was just done. Usually the answer to the question of recovery does not fit into a categorical assertion: all or nothing. Let us consider a patient suffering from typhus. Here difficulties arise from the very beginning. First, the mortality from typhus varies somewhat depending on the epidemic. Knowing the mortality rate for a given time, one could estimate the probability of recovery again by the ratio (number of recovered: number of sick). But this type of prediction is good for statistical conclusions, for example in insurance, and does not at all satisfy the needs of individual prognosis, which is of greatest interest to the physician and the patient. Based on statistics, one can conclude that the disease, although dangerous (giving high mortality), in most cases still ends in recovery. Whether this particular patient will fall into the majority is decided not on the basis of statistics, but on the basis of other considerations. Clinical experience shows that the favorable or unfavorable course of the disease is associated with many circumstances, the significance of which is not always clear. Thus, typhus in women often runs milder than in men, and in children incomparably milder than in adults. With other diseases, the same data may have a different significance. Diabetes, for example, in children runs much worse than in adults. Knowledge of the course of the disease guards against many errors. By the end of the second week, even with a favorable course of typhus, the pulse often becomes weak, blood pressure drops and consciousness becomes clouded. The appearance of these same symptoms in the first days makes the prediction serious. Similarly, it is known that angina pectoris always gives grounds to expect a severe attack, however well the patient feels. To give an absolutely favorable prognosis in this disease would be incorrect. By carefully analyzing the picture of the patient's mental state, the psychiatrist predicts that a period of excitement will follow a period of depression. In other cases, he warns against attempts at suicide. The prognosis worsens with the combination of several diseases. Of particular importance are the so-called complications, which may prove more severe for the patient than the main disease. Their appearance may be extraordinarily complex and even seem completely random. Nevertheless, it is known that with certain diseases certain complications should be expected (pneumonia in a cardiac patient, gangrene in a diabetic, pyelitis in diseases of the spinal cord). With any disease, something unforeseen may arise that will completely change the prediction. This explains why every prognosis must be made with great caution. Therapeutic intervention is also of considerable importance for prognosis. Diphtheria, diabetic coma, gumma, strangulated hernia, dislocations and fractures, with and without treatment, are prognostically evaluated quite differently. In surgical intervention, a separate consideration of the severity of the disease and the severity of the operation is required. The influence of factors not directly related to the disease, living conditions that prevent the patient from being treated, carelessness and unwillingness to change one's lifestyle, obsession with work, often associated with straining forces to physiological limits, also affect the course of the disease and often determine the prognosis. It is not easy to give any general methodological guidance for prognostic judgments. In all cases, it is necessary to mentally imagine the course of the disease, adapting the general scheme of the disease to the particular patient. The further one looks ahead, the more difficult the prediction. To foresee immediate or at least near danger, one can often do so, taking into account consciousness, pulse, character of respiration, secretion of urine, blood formation and other important vital functions, by which we judge the state of the patient's strength. Whatever may have caused the decline of one of these functions, it should always be taken seriously and incline toward an unfavorable prognosis, unless there is a possibility of rapid therapeutic intervention. Let us imagine a person who is blue, covered with sweat, with dilated pupils, a poor pulse and heavy breathing. One has to make a serious prognosis, limiting oneself to nearsighted incomplete recognition of suffocation from an unknown cause. But often the fate of the patient is a cause for concern in the more distant future, when there is a steady decline in nutrition. Cachexia forces one only vaguely to suspect some existing tumor and yet to make a definite poor prognosis. In physics, chemistry and other disciplines, the course of complex phenomena is sometimes depicted by curves. Based on such curves - if they are not completed and observation is interrupted - one can often predict how the process will proceed further, assuming that the 'course of the curve' has been determined. A similar principle is to a certain extent applicable in the clinic. A low-grade fever that has existed for a long time cannot always be explained. Many assumptions can be brought forward to explain it, but none of them is so firmly established as to give a key to prognosis. Direct observation of the patient, who for a long time does not become exhausted or suffer from his temperature, and may even be improving, indicates a favorable course of his disease and allows one to make a good prediction. In the cases just given, the prognosis was made independently of diagnosis, based only on a separate symptom of the course of the disease and evaluation of the general condition. The persuasiveness of the prediction varies, in some cases reaching almost the force of proof, while in others the prognosis is almost a guessing of events. And finally, very often a prognosis cannot be made at all. Prognostic conclusions are subject to a great risk of error. One of the hard-to-eliminate sources of error depends on the personality of the physician, his impressionability and sympathy for the suffering of the patient. One must beware of the overwhelming influence of fresh memories. A similar case just seen involuntently inclines one to a similar prognosis. Errors occur particularly often from insufficient caution, due to which some important aspect of the clinical picture or the patient's surroundings is overlooked. The ability to control one's attention and emotions and to assess the patient's situation soberly does not belong to all to the same degree. In all times there have been physicians who were famous for their prognoses. Hippocrates, who attached such great importance to prognosis and even titled his work 'Prognostikon', was a famous predictor of antiquity. In France, the successful prognoses of Charcot and Bouchard were noted by contemporaries, in Germany - Leyden. In our country, the predictions of S. Korsakov and Zakharyin were particularly valued. The ability to make the correct prognosis and correctly assess the patient's condition is acquired through experience and exercise and is often based on very subtle observation. One can orient oneself with certainty only in a familiar environment. That is why it is so difficult to predict outside one's field. Thus, the general severe condition of the patient, generally familiar to every physician, may seem to the therapist completely hopeless if it occurs after a surgical complication or an eclamptic attack, while the surgeon and gynecologist will look at the matter quite differently.

It is necessary to understand what a 'correct prognosis' means. For an exhausted patient with a nodular liver, large ascites, dyspeptic symptoms, and bloody vomiting, a diagnosis of stomach cancer was made, and a poor prognosis was given on this basis. However, the autopsy does not reveal cancer, but determines that cirrhosis of the liver was the basis of the disease. Although the predicted death occurred, the prognosis was essentially incorrectly justified. If it had been stated that it was impossible to establish a diagnosis, but at the same time a poor prognosis had been given based on the existing general serious condition and loss of strength, then in this case all considerations would have been more correct. However, it is not always easy to decide on the correctness of the prognosis, since the one making the prognosis usually does not provide data to confirm it and often does not even realize how he arrived at the stated prediction. In the example under consideration, the general serious condition of the patient is of decisive importance, which forces one to give a poor prognosis, and on the other hand, inclines one to a diagnosis of a new growth. Meanwhile, to confirm the prognosis, the diagnosis of cancer is put forward as more convincing evidence, and the doctor himself begins to think that the poor prognosis was given based on the serious diagnosis. The temptation to verify the diagnosis with the prognosis particularly often arises, which always requires great caution. If a doctor encounters a pale patient with an enlarged spleen, already suffering from general malaise and elevated temperature for some time, he will be inclined to make a diagnosis of typhoid fever and on this basis predict that the illness will continue for several weeks and end with a gradual decrease in temperature. The prediction comes true. It is easy to take it for a correct prognosis, thereby proving the correctness of the diagnosis. Meanwhile, in the absence of more convincing evidence in favor of typhoid fever, such a coincidence of the prognosis with the actual outcome may turn out to be completely accidental. The picture of the disease could have been caused by pleurisy, which was not noticed, and the enlarged spleen could have been from malaria, which the patient had completely forgotten. A correct and complete prognosis can be recognized only when both the final prognostic conclusion and all the justification for the prognosis have been confirmed. The practical significance of prognosis is enormous. Along with successful treatment from a practical point of view, a correct prediction of the course of the disease has the greatest importance for the patient and those around him. The diagnosis, so important for the physician, is in fact significantly less interesting to the patient and in most cases even incomprehensible. But the physician must also be guided by the prognosis in order not to prescribe pointless, sometimes painful for the patient and difficult for those around him therapeutic measures (for example, sending hopeless patients to a resort) and in order not to miss the chance to save the patient where the situation is mistakenly considered hopeless, where for example energetic surgical intervention, despite blood loss, is sufficient to save the patient.