Impact of Source of Infection on Outcome in Patients with Severe Sepsis and Septic Shock in the Emergency Department

ABSTRACT

PURPOSE: The purpose of this study was to investigate the effect of common sources of infection on outcome in patients with severe sepsis and septic shock in the emergency department (ED). METHODS: We conducted a retrospective observational study involving adult patients who were diagnosed with severe sepsis or septic shock in the ED of a tertiary care hospital during the period between August 2008 and March 2012. We categorized patients according to four groups based on source of infection (respiratory infection, intra-abdominal infection [IAI], urinary tract infection [UTI], and other sources [OS] group). The primary outcome was inhospital mortality. Multivariable logistic regression analysis was performed for adjustment of potential confounders, including age, gender, serum lactate concentrations, the Sequential Organ Failure Assessment score, timely antibiotic use, and achievements of early resuscitation targets. RESULTS: A total of 758 patients were included and overall in-hospital mortality was 16.6%. Significant differences in mortality were observed between four groups (27.5% for respiratory infection, 12.1% for IAI, 2.6% for UTI, and 20.0% for other sources, p<0.01). In patients with IAI, adjusted odds ratios (ORs) for mortality were 0.49 (95% confidence interval [CI], 0.27-0.92) compared with the OS group and 0.57 (95% CI, 0.35-0.93) compared with non-IAI. For UTI, adjusted ORs were 0.08 (95% CI, 0.02-0.32) compared with the OS group and 0.09 (95% CI, 0.03-0.35) compared with non-UTI. For respiratory infection, adjusted ORs were 1.33 (95% CI, 0.74-2.39) compared with the OS group and 2.56 (95% CI, 1.60-4.10) compared with non-respiratory infection. CONCLUSION: Results of our study showed that source of infection was independently associated with in-hospital mortality in patients with severe sepsis and septic shock in the ED. In particular, UTI and IAI showed significant association with in-hospital survival. Patients with respiratory infection showed significantly higher mortality, compared with non-respiratory infection patients.