Early Fever is Associated with Failure of Noninvasive Management and Peak Inflammatory Response in Acute Left-Sided Diverticulitis: A Retrospective Cohort Study

Background: Outpatient nonantibiotic treatment for mild acute left-sided diverticulitis (ALD) is supported by several randomised trials. Identifying factors that predict failure of medical management may facilitate implementation. Objectives: To evaluate the relationship between early fever and outcomes in ALD. Design: Retrospective cohort study. Settings: Regional tertiary hospital. Patients and Methods: Adult patients presenting as emergencies with ALD, confirmed by computed tomography (CT) within 48 h of presentation, and managed initially with noninvasive treatment intent were included. CT findings were graded according to the World Society of Emergency Surgery (WSES) grading system. Early fever was defined as a recorded temperature >37.9°C within the first 24 h. Main Outcome Measures: The primary outcomes were the need for invasive treatment (surgery or percutaneous drainage) and peak C-reactive protein (CRP) >200 mg/L. Sample Size: A minimum sample size of 300 patients was suggested based on previous literature. Results: After exclusions, 444 patients were included. Early fever occurred in 111 patients. Early fever was associated with the need for invasive therapy (odds ratio 3.8, 95% confidence interval 1.3–11.2) and with peak CRP. WSES grade more closely predicted the need for invasive therapy but was poorly associated with peak CRP. Conclusion: Early fever is associated with both the need for invasive treatment in ALD and elevated peak CRP. Appropriate safety-netting is important when outpatient management is undertaken. Limitations: This study was retrospective, and most patients were treated with intravenous antibiotics.