Fever after aneurysmal subarachnoid hemorrhage: relation with extent of hydrocephalus and amount of extravasated blood.

BACKGROUND AND PURPOSE Fever after aneurysmal subarachnoid hemorrhage is associated with poor outcome. Because hydrocephalus and extravasated blood may influence thermoregulation, we determined whether these factors increase the risk for fever after subarachnoid hemorrhage. METHODS Fever within 14 days (subdivided into infectious and noninfectious) was defined as a mean daily body temperature above 38.0 degrees C for at least 2 consecutive days in a prospectively collected cohort of 194 patients with subarachnoid hemorrhage. Hazard ratios were calculated to assess the impact of hydrocephalus (bicaudate index) and cisternal and intraventricular blood (Hijdra score) on the occurrence of fever. Adjusted hazard ratios were calculated in one multivariate model, including other possible confounding factors. RESULTS Infectious fever occurred in 34% of patients and noninfectious fever in 9%. Adjusted hazard ratios of intraventricular blood were 2.2 (95% CI, 1.3 to 3.8) for any fever, 2.4 (95% CI, 1.3 to 4.4) for infectious fever, and 2.0 (95% CI, 0.7 to 5.9) for noninfectious fever. Adjusted hazard ratios of cisternal blood and hydrocephalus for infectious and noninfectious fever ranged from 0.6 to 1.5, all with wide CIs. CONCLUSIONS Intraventricular blood is an independent risk factor for the development of fever. In this study, noninfectious fever was rare and not related to extravasated blood or hydrocephalus.