Diagnostic features of early high post-laparotomy fever: a prospective study of 100 patients.

To define the most important diagnostic signs, symptoms and laboratory findings related to intra-abdominal sepsis in the early post-operative period, 15 binary variables were prospectively assessed in 100 febrile (greater than 39 degrees C) post-laparotomy patients admitted to an intensive care unit. Intra-abdominal sepsis was found alone in 55 patients and in association with an extra-abdominal focus in 11 patients. Fever was related to an extra-abdominal septic focus in 23 patients and no infectious cause was found in 11. Analysis (chi 2) indicated that 6 of the 15 variables were significantly associated with an intra-abdominal focus of infection. The predictive value of each variable, indicated by relative risk, ranked the six variables in order of diagnostic importances: no bacteraemia (1.67), leucocytosis (1.60), ileus (1.50), mental disturbances (1.41), contaminated first laparotomy (1.38), abdominal tenderness (1.22). The absence of bacteraemia was the most important finding separating intra- and extra-abdominal foci of infection. In a febrile post-laparotomy patient with any evidence of sepsis, the absence of bacteraemia should not lull the physician into a false sense of security but rather alert him to the likelihood of an intra-abdominal septic focus.