Spontaneous bacterial peritonitis induced by intraarterial vasopressin therapy.

Two patients developed spontaneous bacterial peritonitis after infusions of vasopressin into the superior mesenteric or gastroduodenal arteries for upper gastrointestinal hemorrhage. The peritonitis in these patients differed from the typical picture in which a single aerobic organism is responsible, by the presence of multiple organisms, some of which were anaerobic. These findings suggest that the arterial vasoconstriction decreased the integrity of the intestinal mucosal barrier and permitted the transmural migration of enteric organisms from the lumen of the bowel into the ascites-filled peritoneal cavity.