Does severe non-infectious SIRS differ from severe sepsis?

Objective: To compare the time course of organ dysfunction/failure, mortality and cause of death in patients with severe sepsis (SS) and patients with severe non-infectious systemic inflammatory response syndrome (SNISIRS). Design: Secondary analysis of a multi-centre inception cohort study. Setting: Twenty-three multidisciplinary intensive care units (ICUs) in Australia and New Zealand. Patients and participants: 3,543 ICU admissions 48 h or < 48 h if SIRS and organ dysfunction present. Interventions: None. Measurements and results: ICU prevalence of SS and SNISIRS was 20% (707/3,543) and 28% (980/3,543), respectively. ICU mortality was similar in patients with SNISIRS and with SS (25 vs. 27%, P = 0.40). Central nervous system (CNS) failure occurred more frequently in patients with SNISIRS (33 vs. 22%, P < 0.001) and resulted in death more commonly than in SS (relative risk = 1.6, 95% confidence interval 1.4-1.7, P < 0.001). The time to peak organ dysfunction (0.67 vs. 0.91 days, P = 0.004), overall episode length (3.6 vs. 5.6 days, P < 0.001) and ICU stay (geometric mean: 4.1 vs. 5.8 days, P < 0.001) were significantly shorter in patients with SNISIRS. Conclusions: Whilst SNISIRS and SS have similarities, including their crude mortality rate, important differences exist. SNISIRS is more common on admission to the ICU, and is more commonly coupled with CNS dysfunction and death from neurological failure. Descriptors: SIRS/sepsis: clinical studies.