Abdominal operations: effect on subsequent experimental faecal peritonitis

Rats were subjected to laparotomy, anaesthesia only (controls), laparotomy plus 1-cm-segment ileum isolation, or no treatment (controls) and were challenged with endogenous faecal peritonitis 1 and 2 weeks later, respectively. Survival rates were 40% for the laparotomy group and 100% for the ileum isolation group, whereas all controls died. The number of peritoneal leucocytes, particularly macrophages and neutrophils, was significantly (p less than 0.05) higher in the laparotomy group than in the control group. The data show that abdominal operations alone--and especially in combination with a minor infectious challenge--entail an increased tolerance to subsequent peritonitis, possibly mediated by the previously stimulated and sensitized leucocytes.