Evidence for the non-infectious etiology of early postoperative fever.

In a prospective study of infections in 871 general surgery patients, we identified 81 patients who developed unexplained postoperative fevers. The majority of these episodes (72%) occurred early (within the first 48 hours) following surgery. Patients who developed early, unexplained fevers differed significantly from patients who developed documented postoperative infections. Patients with unexplained fevers were younger, had less severe underlying disease and underwent less extensive surgeries than patients who subsequently developed infections. In these respects, they were more similar to non-infected, non-febrile patients. We concluded that episodes of early, unexplained postoperative fever occur frequently in a wide range of general surgery patients. Most of these episodes are non-infectious in origin. Patients with early postoperative fevers should be evaluated to identify any obvious sources of infection. If no focus is identified, empiric antibiotic therapy should not be initiated nor should prophylactic antibiotics be extended for prolonged durations. Unexplained fevers will resolve in time without specific therapeutic interventions.