A system of practical medicine. By American authors. Vol. 3

by Unknown

In the first place, it is important to recognize at the earliest moment the development of the pneumonic process during acute bronchitis of the finer tubes. In all cases of the latter, especially in children and in patients of debilitated system, this occurrence must be constantly apprehended. Its occurrence may be strongly suspected if sudden rise in the fever and in the rate of respiration and pulse is noted, though if the areas affected are small, scattered, or deeply seated it may not at first be possible to demonstrate it. It must be remembered also that in the capillary bronchitis of children the fever and disturbance of pulse and respiration may be aggravated quite abruptly from extensions of the disease, so that actually it must be recognized that in such cases the presence of small pneumonic centres can only be assumed, but can neither be proved nor disproved. The course of the pyrexia may afford some assistance, since I believe more marked diurnal variations, amounting at times to distinct remissions, will be noted in cases of catarrhal pneumonia than in those of severe bronchitis not so complicated. In adults less hesitation need be felt in admitting the development of pneumonic foci under such circumstances, even though the physical signs are negative. Usually, however, carefully repeated examination will soon reveal the signs of infiltration in irregularly disposed areas; and I suspect it must be infrequent that the close study of the relative physical signs afforded by examination of the corresponding areas on the two sides of the chest will not afford substantial ground for diagnosis.

It must always be remembered that areas of consolidation arising in the course of severe bronchitis of the finer tubes may be from collapse, and not from pneumonia. This is especially apt to be the case in children, but occurs not rarely in feeble adults. The diagnosis of catarrhal pneumonia from mere collapse must therefore be carefully considered. The occurrence of collapse, though it may be marked by sudden and severe increase of dyspnoea, pulse-rate, and distress, is not accompanied by a corresponding rise of temperature; and this is a point of capital importance. Again, the development of the physical signs is usually much more abrupt than where catarrhal pneumonia is occurring. Considerable areas of dulness on percussion appear in the course of twelve or twenty-four hours, between the successive visits of the physician, without corresponding increase of fever; and these areas may subsequently present marked peculiarities, at times disappearing almost as abruptly, to be succeeded by similar areas in other portions of the lungs, though at times also they persist and pass through the changes already described. The physical signs furnish further assistance. Retraction of the base of the chest during inspiration is much more common in collapse, especially when the areas are at all extensive and when they occur in the lower lobes, since there is necessarily a reduction in the volume of the lungs; and this, added to the inability to inflate the affected lobules, induces this important sign, which should always be carefully looked for. The dulness over collapsed lung-tissue is rarely as marked as over extensive areas of catarrhal pneumonia; the vocal resonance and fremitus are diminished; râles are wanting or are feeble and transmitted; and again, it must be mentioned that the physical signs present remarkable variations within short periods of time. It is, however, necessary to suspect the existence of pneumonic areas in cases of severe bronchitis where portions of lung become collapsed, and continue so, while the general symptoms indicate persistence of inflammatory action. The differential diagnosis is therefore in many instances rather as to the relative proportion of these factors than as to the total absence of either.

Catarrhal may be confounded with croupous pneumonia. This error may most readily be made if the case be not seen until a consolidated area of considerable extent is present, since, as we have seen, in some instances the foci of catarrhal pneumonia may chiefly occupy one lung and may coalesce. Even then, however, the dulness of percussion rarely corresponds with the outline of the lobe, and is rarely as complete as in croupous pneumonia, nor are the bronchial respiration, the bronchophony, and the exaggerated vocal fremitus as pronounced, for the simple reason that the consolidation is not so uniform, and that many of the smaller bronchial tubes are more or less obstructed by swelling of the mucous membrane or by the accumulation of viscid secretions. It will rarely happen, moreover, that strong efforts at respiration—induced, if necessary, by having the patient cough during the auscultation, so as to ensure a full inspiration—will fail to develop subcrepitant râles at some point of the catarrhal consolidation. To this must be added the information drawn from the history of the case; the character of the cough and sputa; and, above all, the atypical course of the pyrexia, and the fact that carefully-repeated examinations will show frequent and abrupt variations in the physical signs around the margins of the affected area. If the case is observed during its development, there will be less difficulty in making a correct diagnosis. The process is very rarely unilateral throughout its development; and the evident bronchitis, the development of irregularly scattered foci of partial consolidation in both lungs, and the frequent coexistence of collapse, combined with the absence of the characteristic symptoms and course of the croupous form, make the nature of the case apparent.

The diagnosis of ordinary pleurisy with effusion from catarrhal pneumonia presents no difficulty. But, on the other hand, it is not easy to recognize the occurrence of a moderate pleuritic effusion complicating a catarrhal pneumonia. The fact that the lower lobes of both lungs are apt to be involved in the pneumonic process interferes with the displacement of the heart, and the enfeebling of the respiratory and vocal phenomena may be attributed to bronchial obstruction or to collapse. A careful study of the outline of the dull area, and of the effect upon it of changes in the position of the patient's body, has proved of service. After all, this is a rare complication; but not so rare is the coexistence of plastic pleurisy with catarrhal pneumonia, and this also may give rise to doubt in the diagnosis. An area of dulness appearing near the base and extending with moderate rapidity, attended with bronchial irritation, with irregular fever of slight or of moderate degree, and with some evidences of engorgement of the lower part of the opposite lung, and presenting over the affected area, in addition to marked percussion dulness, bronchial respiration not of intense concentrated type, distant bronchophony, no increase of vocal fremitus, and crackling râles irregularly scattered over the affected area, represent a clinical condition, occasionally met with in adults, which requires care to ensure its proper interpretation. I have observed crackling râles in particular in such cases, which might have been regarded either as intrapleural or as developed in the finest bronchioles. It will be observed, however, that the degree of dulness is excessive for a mere plastic pleurisy; that the respiratory and vocal signs, while not typical of croupous consolidation, are yet far more developed than would be consistent with the presence of a quantity of plastic pleural exudation sufficient to cause such dulness; that any such grade of plastic pleurisy is very rare; and that the general symptoms and the course of the disease are indicative of much more gravity than would attach to such a pleuritic process if it were to exist. It is altogether probable that there has been here a coexistence of catarrhal pneumonia with a moderate degree of plastic exudation on the corresponding part of the pleura.

Again, it is essential to distinguish catarrhal pneumonia from acute miliary tuberculosis with special localization in the lungs and meninges. This diagnosis may present marked difficulties both in children and in adults, but of course chiefly in the former, and especially at a late period of the case, when cerebral symptoms, closely simulating those characteristic of tubercular meningitis, may have appeared. The irregular fever, the marked disturbance of pulse and respiration, with evidence of diffuse bronchial irritation, but out of proportion to the physical signs of consolidation, the occasional vomiting in the early stage, and the appearance of nervous symptoms, are present in both conditions. But in tuberculosis there may be high fever before any marked evidences even of bronchial irritation appear; there is not so much bronchitis to aid in explaining the dyspnoea; there is not so much tendency to pulmonary collapse, and the physical signs present are more persistent; the pulse presents the characteristic successive stages of alteration; vomiting is apt to be more frequent, while the diarrhoea which is often present in catarrhal pneumonia is replaced by constipation; the Cheyne-Stokes respiration is more apt to appear; and, finally, an ophthalmoscopic examination may reveal retinal tubercles. It remains true, however, that in some cases it must evidently be wellnigh impossible to decide whether the case is one of acute tuberculosis, with a high grade of bronchitis, and very probably with some centres of pneumonic infiltration associated, or one of catarrhal pneumonia developing out of a severe bronchitis. It must be remembered, moreover, that even when the case has begun as one of catarrhal pneumonia there is a tendency to the development of tuberculosis, both pulmonary and general; so that it may be found after death that the nervous symptoms, which were reasonably ascribed to congestion, to high temperature, to prolonged and exhausting nervous irritation, and to the effect of imperfectly aërated blood, are in reality connected with the presence of miliary tubercles in the meninges, while at the same time these have also been developing around the pneumonic foci in the lungs.

It is no less important to bear in mind the necessity for close study in distinguishing between chronic catarrhal pneumonia and phthisis. There are not a few cases of the former where the protracted irregular fever of hectic type, the progressive debility and emaciation, the moist râles, the areas of altered percussion resonance, possibly the signs of a dilated bronchus, and the purulent sputa, may closely simulate true phthisis, but yet which microscopic examination of the sputa for bacilli and elastic fibre, and the effect of treatment and climatic change, prove to be merely inflammatory. On the other hand, it appears undoubted, from the standpoint of clinical observation, that in many cases, especially where a predisposition exists, catarrhal pneumonia terminates in phthisis.

DURATION, TERMINATIONS, PROGNOSIS.—The duration of this disease is highly irregular, and care must be taken not to confound the subsidence of the marked general symptoms with a full restoration of the affected areas. A considerable period is required for this latter process to be effected, and during this interval the lung-tissue continues in a highly sensitive and vulnerable state. Speaking with reference to the obvious symptoms, however, it may be said that mild acute cases may terminate in seven to ten days; fully-developed acute cases, in fifteen to twenty-five days; while the subacute and chronic forms may last several or many months.

Death may occur in from two to four days, especially in weak young children, while more commonly the fatal result occurs from the seventh to the tenth day. Of course in the chronic form death may occur after many weeks or months.

The various terminations are in complete recovery; in apparent recovery, but with vulnerable lungs or general system; in partial recovery, but with residual lesions, such as bronchial dilatation or emphysema; or the disease may pass into the chronic form, associated with chronic bronchitis, or it may lead to the development of acute tuberculosis or of chronic phthisis.

The rate of mortality of catarrhal is much higher than that of croupous pneumonia. Excluding the mild circumscribed form, if such is admitted to exist, as I believe it does, the mortality varies from 30 to 60 per cent. It is apparently less fatal when occurring in the course of measles than in connection with some other diseases, as diphtheria or whooping cough. The nature and tendencies of this disease make it evident that debility and frailty of the patient would render catarrhal pneumonia much more fatal. So it is found that in infants within the year death almost constantly follows, and in older children of bad constitution, especially in those who are scrofulous or rachitic and subjected to malhygienic influences, it is almost equally fatal. After puberty the mortality is chiefly influenced by the constitutional state of the subject and by the extent of the pneumonic process.