Читать книгу Studies on Epidemic Influenza: Comprising Clinical and Laboratory Investigations - University of Pittsburgh. School of Medicine - Страница 21

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In the consideration of any disease the well-trodden path of a painstaking history, a thorough physical examination, and reliable laboratory investigation, together with an intelligent interpretation, will usually lead to a definite diagnosis. In certain diseases, as is well known, the stress must be placed about equally on all of these factors, while in others one or other factor predominates. In influenzal pneumonia, until more is known of the etiology (bacteriology) and of the pathological changes and of the physiological disturbances, the controlling factor in the diagnosis (we feel embarrassed to admit) must be the history. This is true not only of the diagnosis of influenza with or without pulmonary involvement, but is also true of the diagnosis of the various complications, and will be found to be particularly true in the recognition of the bizarre sequelæ, which no doubt in the succeeding months or years will be attributed to or will follow in the train of influenza.

With the knowledge that there is a prevailing epidemic of influenza and that the manifestations are largely in the respiratory tract, any pulmonary disturbance will necessarily make one suspicious of the presence or the oncoming of an influenzal pneumonia in the patient under consideration. The history of the onset, as of simple influenza, is the greatest factor. This with a continued temperature, cough, cyanosis, slow pulse, continued asthenia, or even an unusual leucopenia, may have a greater weight in determining the diagnosis of lung involvement than will the apparently definite or, as it may happen, the confusing chest signs. To differentiate from ordinary bronchitis, broncho-pneumonia and catarrhal pneumonia, one need only refer additionally to the severity and persistency of the disease when it is of the influenzal type, as compared with the mildness of the ordinary type. To differentiate it from croupous pneumonia, one need only compare the confusing symptom picture of the influenzal pneumonia with the definite, clear picture of ordinary pneumonia; or the confusing kaleidoscopic chest signs of the one with the definite, clear-cut signs of the other. The laboratory thus far has been the smallest factor in making the diagnosis, in that sputum examinations, blood examinations, blood cultures and urine examinations are mostly negative in their results, or at least the findings are not specific. We do not, however, mean to indicate that these tests are not of the greatest value. The leucopenia is the one outstanding feature which seems to have separated this infection from other acute lung infections, excepting miliary tuberculosis. The differentiation of influenzal pneumonia from an acute tuberculous process in the lung may be difficult, especially if there is no reliable history available. However, the fact that pulmonary tuberculosis usually begins at the apices of the lungs and influenzal pneumonia at the bases or at the apices of the lower lobes is quite helpful. Of course, the examination of the sputum for tubercle bacilli will be a deciding factor.

The differentiation between influenzal pneumonia and diseases of the pleura is one which practically rarely needs to be made, for there seem to be very few cases of influenzal infection of the lungs in which the pleura is not also involved to a greater or lesser extent.