FIG. 61-Section through the posterior parts of lungs showing advanced pulmonary tuberculosis. The right upper lobe shows several empty cavities, one of which is superficial, large, and surrounded by stiff fibrous walls. High up in the axillary region one should expect to find metallic tympany; amphoric breathing; clear-cut, metallic râles; whispered pectoriloquy, and if the bronchus leading into the cavity is stenotic, cracked-pot sound. The left upper lobe shows diffuse infiltration which would yield the following physical signs: diminished expansion, dulness, increased vocal fremitus and resonance, bronchovesicular breath sounds, crepitant and crackling râles. The position of the liver and spleen in relation to the chest wall, lung and stomach is well illustrated. to lack of vibratability and may be imitated by percussing the inner surface of the tibia. It is the note heard over consolidated lung tissue. It has less volume (wave amplitude) than resonance and does not carry far. 4. Flatness is absolute dulness. It is a very short, high-pitched nonmusical note, with very little carrying power (intensity). It is heard in percussion of viscera such as the heart and the liver in regions not covered by lung tissue and may be exemplified by percussing the thigh. It is the note of liquids and is heard over pleural or pericardial effusions. It is invariably associated with a marked sense of resistance. SPECIAL PERCUSSION SIGNS Wintrich's Change of Note. This consists of a change of pitch during percussion, which varies according to whether the mouth be opened or closed, the note being higher in the former, and lower in the latter instance. In a pipe open at one end, any constriction of the opening lowers the pitch of the sound (Bernoulli). It may be demonstrated by percussing the trachea with the mouth open, and closed. This phenomenon may occur pathologically if a pulmonary cavity or a pneumothorax communicates with an open bronchus. It occurs rarely in pneumonia and is to be explained by conduction of the percussion stroke, through the consolidation to a large bronchus. If noted in recumbency only, this may be due to temporary occlusion of the bronchus by fluid. This sign is of but little practical value. Gerhardt's Change of Note. This consists of a change of the percussion sound, with a change of the patient's posture, and is dependent upon an alteration in the direction of the long axis of a cavity, which contains both air and fluid. This was formerly explained as resulting from a change in the length of the air columns. This is incorrect since the greatest possible differences in lung cavities are too small to account for such changes in sound. The real explanation must be sought in the change in tension which as a result of the contained fluid, the cavity undergoes (Geigel). Friedreich's Change of Note.-This phenomenon consist of a lowering of the pitch of percussion note over a cavity during forced inspiration, due to an increased volume of air. It is, therefore, supposed to indicate a patulous, flexible cavity. Biermer's Change of Note.-This phenomenon is practically the same as Gerhardt's, except that the former described the metallic resonance sometimes heard over a pneumothorax. The pitch is lower on sitting up, due to an increased volume of the pleural cavity, caused by a sagging of the diaphragm owing to the weight of the effusion. None of the foregoing changes of note are of much practical importance. They are rarely demonstrable, and even when so are often of doubtful significance. The Lung Reflex.-Local irritation of the skin, by cold, mustard, or continued percussion, may temporarily produce a reflex dilatation of the subjacent lung tissue a relative emphysema-which may be sufficient to obscure slight degrees of percussion dulness. Thus too-prolonged percussion of a pulmonary apex may temporarily cause the disappearance of a slight impairment of resonance which was readily demonstrable at the beginning of the examination. It should not be forgotten, however, that aural fatigue on the part of the examiner may account for a similar result. When such an occurrence is suspected, the examiner may proceed to some other step in the examination and revert to the examination of the doubtful region after some time has elapsed. CHAPTER V ANATOMIC CONSIDERATIONS The right ribs are longer, the right lung larger (but shorter), the right shoulder often lower and narrower, the right breast is higher and further from the mid-sternum, than the left. The Lungs. The apices extend from 1 to 11⁄2 inches (2.5 to 4 cm.) above the clavicles. The right apex is slightly smaller than the left, its conical shape is due to encroachment of the right innominate vein. This vessel, unlike the left, pursues an almost vertical course, and with the superior vena cava, occupies the space which on the left is filled by the anterior, inner margin of the pulmonary apex. In addition to this the subclavian artery pursues a course more anterior and less mesial, to the right apex than the left. The left apex is more dome-like and slightly larger. There is practically no difference in the height of the apices on the two sides. These con The percussion note from the right upper apex to the second interspace is slightly higher-pitched, less resonant, and at times has a slightly tympanitic quality because: (1) The right apex is smaller. (2) The superior vena cava lies in front of the inner part of it. (3) The right subclavian artery occupies a more anterior, the left, a more mesial position. ditions account for the diminished resonance and higher pitch. (4) The right apex lies in immediate contact with the trachea (Figs. 49, 52,76,77,97). This accounts for the tympanitic element and in part for the elevation of pitch. (5) A slight influence with light percussion-is sometimes exercised by increased thickness of the right pectoral muscles. SURFACE LANDMARKS, ETC. THE RIGHT LUNG THE LEFT LUNG Turns out at the 6th costo-sternal articu- Turns out at the 4th costo-sternal articulation (sternal line). Crosses the 6th and 7th intercostal space Reaches 8th rib in axillary line. lation. Turns out at the 5th costal space. Louis' angle (the junction of the manubrium with the gladiolus) marks the sternal attachment of the second rib. It is opposite to the but was named after Louis, the great French clinician, Ludwig being the German for 'Louis' angle, not Ludwig's angle. It was not described by Ludwig, the German, Louis. The angle was originally described by Louis as a unilateral prominence of the ribs noted in certain cases of emphysema on the most affected side. (E. H. GOODMAN: "Historical Note on the So-called Ludwig's Angle or Angle of Louis." Medical Record, July 23, 1910.) CI FIG. 62.-Mediastinal surface of lungs hardened before removal. This photograph shows (a) the groove produced in the right apex by the trachea; (b) the relatively anterior position of the vessels on the right side; and (c) the smaller size of the right apex. AG, azygos groove, VG, grooves for superior vena cava, innominate vein, and subclavian vessels; TG, tracheal groove; SG, subclavian groove; AAG, aortic groove; CI, cardiac impression. FIG. 63.-Lateral view of lungs hardened before removal. This photograph shows the deeper vascular groove and the smaller size of the right apex as compared with the left. FIG. 64.-Anterior view of lungs hardened before removal. This photograph shows the anterior position of the groove for the subclavian vessels on the right side, compared with the more superior position on the left. SG, subclavian groove. previously hardened dissection shows: an infant's chest, displaying a shrunken thymus FIG. 65.-The lungs normally meet and frequently overlap at Louis' angle. This gland between the apices of the lungs. (Fetterolf and Gittings.) |
