A physical examination of the chest may not at first discover any signs of the inflammatory lesion in the lung. Often two or three days elapse before any characteristic changes are to be discovered by the finger or the ear. Usually on the first day or two the percussion-note is normal, and with the stethoscope we find merely a sonoro-sibilant rhonchus scattered more or less widely over the lung. Even when consolidation occurs, if this be situated in the middle of • a lobe, we may find bronchial breathing, with a puff of fine crepitation at the end of inspiration, but the percussion note may be normal as long as a thin layer of healthy lung-tissue intervene between the diseased spot and the surface.
In an ordinary case the physical signs of the disease are as follows : During the stage of engorgement inspection can seldom discover any im pairment of movement on the affected side. In young children this is always difficult to detect, for the respiration being chiefly diaphragmatic, the chest-walls take a comparatively small part in the respiratory move ment. There may be at first no dulness on percussion, or the note may have a slightly higher pitch than that over the sound lung. The breathing is very harsh and rather louder than natural, and towards the termination of this stage a fine puff of crepitation is caught at the end of inspiration. This is usually only to be heard when the child draws a deep breath. In ordinary breathing there may be a little coarse bronchitic rhonchus both with inspiration and expiration which presents nothing characteristic.
In the stage of hepatisation a faint vocal vibration may be sometimes detected over the affected side when the child speaks or cries. This sign is a very capricious oue. It may be noticed in very young subjects and be absent in a much older child. If present, it is a sign of value, but no inference can be drawn if it fail to be perceived. The over the affected part is now dull ; but the dulness is far from being complete, as in pleurisy. The sense of resistance, too, although increased, is not extreme, as in the case of effusion. It is rather greater than natural, and that is all. In babies and young children the increase of resistance may be very trifling. Auscultation over the consolidated spot discovers a loud tubular breath-sound, and the crepitation, which was before heard at the end of inspiration, is now no longer to be perceived, although at the borders of the solidified region it may still be detected. If the child can be persuaded to speak, the resonance of the voice is high-pitched and sniffling, and is conducted with much greater distinctness than natural to the ear. This sign is, however, not always present, and in a case of un
doubted consolidation the resonance of the voice may be normal. Indeed, in exceptional cases—owing possibly to plugging of a tube with mucus— vocal resonance, and even blowing breathing itself, may be indistinct and distant-sounding, or even altogether suppressed. On the other hand, if the consolidated spot is in the middle of a lobe, completely surrounded by healthy tissue, and the patient be an infant, a bronchophonic resonance of the cry may be the only sign to be detected of the pulmonary lesion.
When resolution occurs in the affected part, crepitation returns, coarser and more like bubbling than before ; the breath-sound becomes less high-, pitched and metallic, and gradually loses its blowing quality. The dulness also diminishes and finally disappears. Returning crepitation is often absent in the child, and resolution frequently takes place without any moist rhonchus being heard. The excessive resonance of the voice and cry usually persist over the affected spot for some time, or until the consolida tion has completely disappeared. Resolution is carried on more rapidly in some children than in others. In many cases, however, when dulness per sists for some weeks after subsidence of the general symptoms, the impair merit of the percussion-note is due to a layer of lymph over the pleura at the affected spot.
The physical signs just described usually occupy the lower two-thirds of one side ; but may be found at any part of the lung. Often they are confined to the apex ; or may be discovered over a limited area under one of the arms. As has been already observed, they are often slow to de velope ; and therefore, when from the general symptoms croupous pneu monia is suspected, frequent and complete examination should be made until the situation of the local lesion is discovered. An important pecu liarity of this form of disease is that the physical signs, unless situated at the apex of the lung, are usually confined to one aspect of the chest. If they are detected at the posterior aspect, the signs are normal in front ; while inflammation of the anterior part of the lung produces no alteration of resonance or respiratory sound at the back of the chest. Therefore a complete examination of the chest must be made before we are justified in saying that no signs of pneumonia are present.