Does the time of onset of severe sepsis in a surgical intensive care unit influence mortality rates: a single-center retrospective analysis

Abstract

Purpose: The purpose of this study was to investigate possible differences in characteristics and mortality rates between early- and late-onset severe sepsis in surgical intensive care unit (ICU) patients.

Materials and methods: Prospectively collected data from all adult patients (>18 years) admitted to our 50-bed surgical ICU between 1st March 2004 and 30th July 2006 were analyzed retrospectively.

Results: Of 5925 patients admitted during the study period, 234 patients (3.9%) had severe sepsis: 74 (31.6%) early onset and 160 (68.4%) late onset. Respiratory infections (48.1 versus 27.0%, P = .002) and infections of unknown origin (21.9 versus 12.2%, P = .005) were recorded more frequently in patients with late-onset than in those with early-onset severe sepsis; abdominal infections were more frequent in early-onset than in late-onset severe sepsis (20.3% versus 7.5%, P = .005). Gram-positive infections were more frequent in late-onset than in early-onset severe sepsis (63.1 versus 51.4%, P = .036). The time of onset of severe sepsis was not independently associated with an increased risk of ICU (early versus late: odds ratio, 1.1; confidence interval, 0.78-0.59; P = .786) or in-hospital (early versus late: odds ratio, 0.68; 95% confidence interval, 0.36-1.29; P = .689) death.

Conclusions: Patterns of infection are different in patients with early-onset and those with late-onset severe sepsis. The time of onset of severe sepsis in surgical ICU patients has no impact on mortality. These data may be important in risk stratification and may be useful in resource allocation in the ICU.