In children, bronchial breathing rarely disappears before the seventh day. It is often accompanied by the subcrepitant râle. When resolution takes place, bronchial breathing and the subcrepitant râle will disappear at the same time.
In old age, inspection, palpation, and percussion give similar results as in adult pneumonia. On auscultation coarse crepitating sounds and loud gurgles are often heard at a distance from the site of the pneumonia. The râle redux is not distinctive of or peculiar to the third stage of senile pneumonia. The sounds heard during this stage are called mucous crepitations, by which is meant liquid crepitating râles produced in tubes intermediate between the bronchioles and the larger bronchi.
If pneumonia terminates in purulent infiltration, the temperature remains high and symptoms of great prostration are developed. The bronchial breathing continues, and becomes more intense, dulness on percussion persists, and sharp, high-pitched râles resembling fine gurgles are abundant.
The occurrence of abscess or gangrene is indicated by the physical signs which attend the formation of cavities in consolidated lung-substance.
No one of the physical signs which is present in the different stages of pneumonia is sufficient for a diagnosis, but the manner and order of their occurrence, and their relation to the symptoms which mark the different stages of the disease, enable one to reach a positive diagnosis in all typical cases. The only symptom of croupous pneumonia which can be regarded as diagnosticated is the sputum.
The physical signs of pulmonary abscess in the aged are very generally wanting. Distinctly localized gurgling and cavernous respiration may, when taken in connection with the rational signs, suffice for an approximate diagnosis, but the great rarity of abscess in old age should make one cautious in its diagnosis. The sputa will greatly aid in such cases.
The physical signs of senile pneumonia are subject to greater variations than ever occur in pneumonia in the adult, and often they do not even follow the course, irregular as it is, which has just been described.
Gray hepatization or abscess may be reached without any distinctive auscultatory signs, even after repeated and careful examination. The râle redux of resolution may be absent, dulness and bronchial breathing being immediately followed by normal (senile) resonance without crepitation. This occurs most frequently in the typhoid variety.
DIFFERENTIAL DIAGNOSIS.—In typical cases of croupous pneumonia (except in childhood and old age) the diagnosis is not difficult. The prolonged chill of invasion, the rapid rise of temperature, the accelerated, panting respiration, pain, cough, characteristic sputum, increase in vocal fremitus, dulness on percussion, the crepitant râle, bronchial breathing, and bronchophony are sufficient to establish the diagnosis.
Croupous pneumonia may be confounded with acute pulmonary congestion and oedema, capillary bronchitis, pleurisy, hypostatic congestion, catarrhal pneumonia (in children), pulmonary apoplexy, meningitis, and typhoid fever.