PERCUSSION OF THE ABDOMEN.
It will often be necessary, however, as in case of the presence of free fluid in the abdominal cavity, to use the lateral or the knee-elbow (Schonlein) position. It is best to percuss with the finger against the exposed skin, either through the medium of a plexirneter or directly on the finger, the latter having the advantage that during percussion we also obtain information in regard to local con sistency, which may have escaped the examiner during palpation.
The results obtainable from abdominal percussion are far inferior to those from the thoracic, since the condition of the intestine, as regards con tained air and ingests, differs, and hence the normal percussion tone; and since the individual organs vary in position, according to the of their mesentery, and also since they readily change iu position, we are often unable to determine with certainty such position. In addition we lack the ability of comparing the note on corresponding sides, which assists us so much in detecting slight alterations in case of thoracic per cussion.
Percussion of the abdomen affords exact information in regard to the position of all the viscera. A common fault of the examiner is that per cussion is made too forcibly, whereby he is likely to overlook slight dull ness. Changes in the percussion note, however, aro of value, in that we thus obtain information in regard to the thickness of the tissues. Dif ferences in the pressure, also, of the finger or pleximeter give varying results, for when we press in deeply, we push the coils of intestine to one side, and obtain on percussion the dullness below them, which on gentle pressure would not have been noted.
We need not emphasize the fact that before resorting to percussion, the bladder and the rectum should be emptied. It is best also to percuss after a regular order, as, for instance, from the ensiform cartilage down to the symphysis, then in the mamillary and in the axillary line, next from the umbilicus transversely to the right and the left into the lumba.. regions.
Since abdominal palpation gives, in general, much more certain in formation, percussion is generally only of value in determining as to whether intestine lies above the examined object or not, and it can only answer this purpose where the intestine contains gas. Mader has resus citated the old method of filling the intestine with water or gas, even as Rosenbach administers seidlitz powder before examining the region of the stomach. Further, percussion is an adjuvant to palpation, in cases where the latter cannot be satisfactorily resorted to, as in case of great tension or hyperesthesia of the abdomen, or when an abdominal tumor is so soft as to escape palpation, or when the tumor is so large as to reach to the ribs, where its upper border is beyond the reach of the palpating hand.
The intestine distended by gas may be recognized by percussion, and we thus possess a means of determining the relation of the intestine to tumor, or to fluid in the abdomen. We are thus able to differentiate
tumors one from another, and from connection with the liver or spleen, by the tympanitic note which percussion of the intestine lying between them gives. In case there is present free fluid in the peritoneal cavity, it always seeks the lowest point unless it be encapsulated or adhesions interfere with its free movement. The intestine distended by gas floats on top of the fluid, and when the patient occupies the dorsal position, it lies against the anterior abdominal wall in the neighborhood of the um bilicus, provided, of course, that the mesentery permits. When the patient alters her position, the fluid still gravitates downwards, and the intestines rise upwards. In case of ascites then, the patient being in the dorsal position, we will obtain tympanitic resonance in the centre of the abdomen, and dullness in both lumbar regions. When the patient lies on her right side, the note will be dull there and tympanitic on the left. The results of percussion are here very precious, when we have to diffeientiate between free fluid in the abdominal cavity, and a tumor containing fluid. We may fall into error, however, in case there be no gas in the intestine or it be not empty. When the intestines are die tended by fluids or by solids, they no longer float on the fluid, but being heavy they sink to the lowest point.
In case an ovarian cyst occupies the middle of the abdomen, close to the anterior abdominal wall, tympanitic resonance will be detected on both sides. Still there are many conditions which may alter this. In case there are adhesions which divide up the abdominal cavity, or if the ascitic fluid is encapsulated, then, of course, the characteristic alterations in position will be wanting. The same holds true of shortening of the mes entery, as frequently happens in chronic peritonitis, when the intestine cannot, in consequence, reach the anterior abdominal wall, and, there fore, at the highest point of the abdomen there is dullness. By deep pressure on the ploximeter, however, as Peter Frank pointed out, we may displace the fluid and obtain a tympanitic note. Small quantities of fluid may escape recognition if the patients lie with flexed thighs, for then the fluid flows down into the pelvis; we had better, therefore, per cuss in the dorsal position with the nates elevated, or else in the knee chest position. Excessive amounts of fluid are not characterized by alteration in level on change in position.
In case ascitic fluid in small amount is present in the abdominal cavity, loops of intestine may gravitate to the lateral regions, and give a tym panitic note in the presence of fluctuation, while in case of cystic tumors the note is dull in the presence of fluctuation. This is a valuable diag nostic point which we owe to Spencer Wells.