Investigate the prevalence of SIRS following SAH and the association between SIRS and SAH outcome.

Emerging evidence suggests systemic inflammation may affect SAH outcome. The association between SIRS during early brain injury (EBI) and SAH outcome is not known.

Consecutive SAH patients admitted (2009–2014) to a tertiary hospital were identified using ICD-9 code. Records were systematically reviewed for SIRS criteria (heart rate >90, temperature >38C or <36C, respiratory rate >20, WBC >12K or <4K) and assignment of World Federation of Neurological Surgeons (WFNS) and modified Fisher grades. Good outcome was defined as modified Rankin Scale (mRS) <2 at discharge and at 30 days post-SAH. SIRS burden was defined as the number of SIRS criteria met.

In our cohort of 130 patients, SIRS prevalence was 66.5% (0-3 days), 58.3% (4-7 days), and 56.2% (8-14 days) post-SAH. WFNS on admission positively correlated with SIRS burden during the majority of SAH course. Meeting >2 SIRS criteria during the majority of SAH course is associated with poor outcome at discharge (p = 0.0013 - 0.37). Increase in SIRS burden on post-SAH days 1-12 is associated with poor outcome at discharge (p = 0.0029 – 0.14). SIRS burden during the majority of post-SAH days is independently associated with poor outcome after adjustment for WFNS grade and age (p = 0.0027 – 0.34).

SIRS is prevalent throughout the first 14 days of SAH with the highest prevalence during EBI period. Worse initial SAH clinical grade is associated with greater subsequent SIRS burden, suggesting SIRS may reflect severity of SAH injury. Increased SIRS burden during acute SAH is independently associated with worse functional outcome at discharge after adjusting for known SAH outcome predictors (WFNS and age).  Future studies are needed to validate these results and evaluate the mechanism by which systemic inflammation affects SAH outcome.