BACKGROUND: The role and impact of systemic inflammatory response after 
aneurysmal subarachnoid hemorrhage remain to be elucidated.
OBJECTIVE: To assess the time course and correlation of systemic inflammatory 
parameters with outcome and the occurrence of delayed ischemic neurological 
deficits (DINDs) after subarachnoid hemorrhage.
METHODS: Besides the baseline characteristics, daily interleukin-6 (IL-6), 
procalcitonin, C-reactive protein levels, and leukocyte counts were 
prospectively measured until day 14 after subarachnoid hemorrhage. Occurrence of 
infectious complications and application of therapeutic hypothermia were 
assessed as confounding factors. The primary end point was outcome after 3 
months, assessed by Glasgow outcome scale; the secondary end point was the 
occurrence of DINDs.
RESULTS: During a 3-year period, a total of 138 patients were included. All 
inflammatory parameters measured were higher in patients with unfavorable 
outcome (Glasgow outcome scale score, 1-3). After adjustment for confounding 
factors, elevated IL-6 and leukocyte counts remained significant risk factors 
for unfavorable outcome. The odds ratio for log IL-6 was 4.07 (95% confidence 
interval, 1.18 to 14.03; P = .03) and for leukocyte counts was 1.24 (95% 
confidence interval, 1.06-1.46, P = .008). The analysis of the time course 
established that IL-6 was the only significantly elevated parameter in the early 
phase in patients with unfavorable outcome. Higher IL-6 levels in the early 
phase (days 3-7) were associated with the occurrence of DINDs. The adjusted odds 
ratio for log IL-6 was 4.03 (95% confidence interval, 1.21-13.40; P = .02).
CONCLUSION: Higher IL-6 levels are associated with worse clinical outcome and 
the occurrence of DINDs. Because IL-6 levels were significantly elevated in the 
early phase, they might be a useful parameter to monitor.