Percussion over the affected pleura is often painful. At first a slight dulness over one lung behind and low down almost always shows itself.
One must percuss lightly, otherwise the percussion note elicited by a thin layer of fluid will be drowned by the co-vibrations of the lungs (see Fig. S7).
With the increase of the effusion, the dulness gradually extends further upwards and spreads out toward the sicle and to the front, taking in Traube's space on the left and generally diminishing behind above to below in front. Should an effusion develop where adhesions of the pleural folds already exist, the lung may be held fast behind and below, and the effusion will then accumulate more above, laterally and in front, producing a corresponding dulness (see Fig. SS).
The feel of great resistance encountered by the percussing finger is very characteristic. On account of the thin elastic chest wall, it is much more marked in the child than in the adult. It alone often permits a diagnosis of pleurisy. The dulness diminishes near the upper border of the effusion, where it is tympanitic. In younger children with large effusions the note is never as flat as in adults, because the underlying lung still makes itself manifest as long as it is not completely cout pressed. In a very large effusion, which reaches the t hi rd ri b anteriorly, the note is very tym panitic and often hyper-resonant beneath the clavicle. Among others, Rauchfuss has called attention to an important of dulness. In a pleuritic effu sion on the one side, which as a rule extends as far as the verte bral column behind, there is also often found on the sound side adjacent to the vertebral column a striplike area of dulness in the form of a small triangle. The apex of this triangle reaches ahnost as high as the dulness on the affected side, and its base, 2-5 cm. in breadth, passes. over into the liver dulness below.
The displacement of adjacent organs by large effusions is almost pathognonionic of plemisy. Tu left-sided effusions, the heart is pushed to the right very early, the apex beat being displaced to the right of the sternum, and the cardiac dulness as far as the right mammary line. In right-sided effusions the heart may move to the middle axillary line. The descent of the liver is very significant in right-sided effusions, but the depth and unequal position of the lower bortler of the liver in the child during health must be taken into consideration. In an effusion filling
an entire side, the dulness will extend to the distant border of the sternum anteriorly,—an important sign.
In pleuritic effusions auscultation is of less value in diagnosis than percussion, and may- readily lead to errors, because the respiratory murmur is often almost normal even in not inconsiderable effusions. Of course in a large effusion the vesicular breathing is usually diminished or absent. On the other hand, it is quite frequently the case that dis tinct bronchial breathing and bronchophony are heard over an effusion in acute cases, and sound as if coming from a distance. The bronchial breathing disappears only after some time, if a large effusion leads to compression of the lung. Fremitus is, of course, always diminished or abolished over the area of an effusion; but it is often difficult to prove. "Egophony is seldom heard in younger children.* Pleuritic friction is heard less often in the beginning of a pleuritic effu sion than during absorption above the boundary of the effusion. Crepitant Hiles are, at times, over tbe upper border of the dulness during inspir ation (unfolding r&les). Tinkling rates are not infrequent; and in isolated cases almost amphoric breathing is heard to the left over the stomach.
If the physical examination has demonstrated the presence of a pleuritic effusion, the physician is confronted by the important question whether he is dealing with a serofibrinous or a purulent (empymna) effusion. Only rarely is differentiation possible from the local finding, much more from the origin and the whole course of the disease. One can say, therefore, with some truth that serofibrinous and purulent pleurisy are two very different diseases as to their origin, symptoms, course, prognosis, and treatment (Barthez and Sanne). And certainly it is not proper to regard an empyeina as a mere reinforcement and an advanced stage of a serofibrinous pleurisy, but one must agree to a great extent with those (Dieulafoy, Netter, and others) who say that an acute pleuritis is destined from the beginning to be or not to be puru lent. A short and separate consideration of the two forms is therefore apropos here. If we have not yet niade this distinction clear, it was for the purpose of avoiding repetition, and because the physician learns to distinguish the two forms only during the course of the disease.