Pulmonary apoplexy is rarely met with independent of valvular disease of the heart or pyæmia. It is a non-febrile disease, while pneumonia has marked pyrexia at the onset. In pulmonary apoplexy dyspnoea is very intense and comes on abruptly; in pneumonia it comes on slowly and progressively increases. The expectoration in pulmonary apoplexy consists of small, black sooty-looking coagula, while in pneumonia the viscid fibrinous mass contains numerous cell-elements other than blood-corpuscles. In apoplexy the dulness is distinctly circumscribed, and around it moist râles are heard, while in pneumonia the area of dulness is more extended and râles are heard over the seat of the dulness. The urinary symptoms are negative in pulmonary apoplexy; in acute pneumonia the chlorides are diminished or absent. There is a peculiar acid odor to the breath—an odor like that of tincture of horseradish—in pulmonary apoplexy, never found in pneumonia.47
47 Guéneau de Mussey.
When croupous pneumonia has its seat at the apex of the lung, it may be confounded with the first stage of phthisis. But the history of a chill followed by the characteristic pneumonic symptoms will generally enable one to make the differential diagnosis. Besides, the fever in phthisis is irregular and is subject to irregular exacerbations and remissions. If the signs of consolidation persist with little or no change, if the temperature at no time falls to normal, if there are night-sweats, if emaciation is progressive,—then the case is to be regarded as one of phthisis, even though there may have been pneumonic consolidation complicating it.
In children pneumonia is so frequently accompanied by marked nervous symptoms that it may be mistaken for meningitis. Meningitis is developed insidiously; has but slight febrile symptoms (102–103° F.), which remit with comparatively great regularity; has a pulse which is often slower than normal; has no thoracic symptoms, no dyspnoea nor accelerated breathing; the face is pale and anxious; and the physical signs of pneumonia are absent.
Sometimes a latent pneumonia with typhoid symptoms is mistaken for typhus fever: especially is this the case when the latter is prevailing. I frequently saw cases where such a mistake had been made while in charge of the typhus-fever patients on Blackwell's Island during a typhus epidemic. In these cases there will be active typhoid symptoms, such as dry tongue, delirium, high temperature, etc. The countenance in this pneumonia, although the cheeks may have a purplish hue, does not exhibit that dull, heavy leaden expression so commonly seen in typhus fever. Although there may be delirium in both instances, the delirium in the former disease is of a milder type than in the latter. The characteristic pneumonic expectoration is often absent in this class of cases; therefore it cannot be relied upon as a point in the differential diagnosis. If pulmonary consolidation is a complication of typhus fever, it will not be developed until after the sixth day of the fever, the time when the eruption is visible. If no eruption is present, the pneumonic consolidation may be regarded as the primary affection, and the symptoms which simulated those of typhus fever may be regarded as secondary.
Pneumonia with typhoid symptoms is sometimes mistaken for typhoid fever. It is called typhoid pneumonia. The differential diagnosis is not difficult if one remembers that the pneumonia which complicates typhoid fever does not come on until late in the fever, and the regular history of typhoid fever precedes its development. On the other hand, when the typhoid symptoms are present from the beginning or come on at the end of the second stage of pneumonia, the physical signs of pneumonia will attend or precede the typhoid symptoms. If a patient over sixty years of age with this type of pneumonia is not seen until the second or third week of his sickness, although evidences of lung-consolidation may be found, it will be very difficult to decide whether the pneumonia is or is not complicating a typhoid fever; and under such circumstances a differential diagnosis may be impossible.
PROGNOSIS.—The mortality-rate of pneumonia is shown by the following statistics: Of 12,421 cases treated in the hospitals at Stockholm, 11 per cent. died. In the Vienna hospitals 24 per cent. died. The Basle hospital's report for thirty-two years gives 23 per cent. of deaths, Grisolle reports 59 per cent. of deaths in those over sixty years of age. In the United States medical reports from May 1, 1861, to July, 1866, of 61,202 cases which occurred among the white troops, 14,738 died, or a little more than 24 per cent.; and of 16,133 among the colored troops (for the same period) 5233 died, or nearly 33 per cent. The deaths from all other inflammatory diseases of the respiratory organs for the same period were only one-seventh as many as from pneumonia. The Confederate hospital reports give the rate of mortality from pneumonia for twenty-five months of the same period as 331/3 per cent. Of 255 cases treated in my wards in Bellevue Hospital during a period of four years, the rate of mortality was 34 per cent.
The statistics given of private practice differ remarkably from those of hospital reports, and are somewhat contradictory. Of Lebert's 205 cases, 73/10 per cent. died. Ziemssen lost only 31/3 per cent. of his cases. Bennett (mentioning, however, that no complication existed) lost none of his 105 cases. Brundes of Copenhagen lost more than 21 per cent. of his 142 cases. Wilson Fox gives to pneumonia the fifth, and Walsh the third, place among fatal diseases. The mortality-average from all the published reports to which I have had access gives 20.1 per cent. of deaths.
From such facts it must be admitted that a disease in which death occurs in 1 out of every 5 cases should be classed among the very fatal diseases. But the death-rate varies very much at different times: it is to-day the same as when Andral wrote, nearly fifty years ago. He stated that it varied from 33 to 2 per cent. There can be no doubt but that treatment somewhat influences the variations in the mortality-statistics, but not to such an extent as to account for the great differences in the reports of different observers.
The prognosis depends more upon the age of the patient than upon any other single element. In infancy the mortality is greater than in early childhood, in which period statistics give from 4 to 6 per cent. as the ratio. The period of dentition seems to influence the prognosis in children. Between the ages of forty and sixty the death-rate is from 10 to 25 per cent.; uncomplicated cases will recover. After sixty the prognosis is exceedingly grave, and the greater the age of the patient the less are the chances of recovery.