INFLAMMATION AS A MAJOR CAUSE OF FLUID LOSSES IN SMALL-BOWEL OBSTRUCTION

The importance of inflammation for fluid losses in obstructive ileus w as investigated in vivo in the rat. Inflammation was quantified by spe ctrophotometry of extravasated Evans blue (Eb)-albumin. Net fluid secr etion in the obstructed jejunum was measured by a continuous gravimetr ic technique. The inflammation in the obstructed gut wall was signific antly more pronounced than that in the gut distal to the obstruction a nd the sham-obstructed gut. The inflammation was significantly more pr onounced in the serosa and external muscle layer than in the mucosa-su bmucosa. Acid-base balance in obstructed animals showed a significant metabolic alkalosis, whereas serum albumin and electrolytes were norma l. Lumen fluid in obstructed animals showed low levels of albumin and total calcium as compared with serum, whereas fluid from the peritonea l cavity of obstructed rats showed high contents of albumin. Indometha cin and hydrocortisone given intravenously to obstructed animals signi ficantly reduced the degree of extravasated Eb-albumin in the obstruct ed gut wall. Sham-operated animals showed net fluid absorption, wherea s obstructed rats showed net fluid secretion. Secretion in obstructed animals was in all cases reversed into net fluid absorption after intr avenous administration of indomethacin and hydrocortisone. These findi ngs suggest that a pronounced inflammation occurs in the wall of the o bstructed small intestine and that this inflammation prays an importan t role in the pathogenesis of the profuse fluid losses of obstructive ileus.