Risk factors for severe sepsis in secondary peritonitis

Abstract

Background: The incidence and risk factors for severe sepsis (SS, organ failure associated with infection) in the context of peritonitis are not well established; thus, it is not clear which patients require more aggressive operative or pharmacologic intervention. We set out to determine risk factors for severe sepsis in a large cohort of patients with intra-abdominal infection.

Methods: Patients admitted for peritonitis over a four-year interval were identified using a Washington State administrative hospital discharge database. This cohort was identified by ICD-9 CM diagnoses and diagnosis-related group (DRG) assignment. Patients with organ failure were identified by ICD-9 CM diagnoses codes using a previously validated classification scheme. Independent risk factors for SS were identified using stepwise Poisson regression.

Results: A total of 11,202 patients with peritonitis were identified, 11% of whom developed SS. The crude relative risk of death in patients with SS was 13 (95% CI, 11.1-15.2) times greater than those without. Severe sepsis was present in 424 (62%) of the 686 decedents. Multivariate analysis showed that source of infection, extent of peritonitis, increasing age, and pre-existing organ dysfunction were independently associated with SS.

Conclusions: Severe sepsis complicates the course of 11% of all patients with peritonitis. Risk factor analysis identifies a subset of patients at greatest risk for severe sepsis. These are the patients who should be targeted for evaluation of novel pharmacologic interventions or more aggressive surgical intervention.