Association of Platelet and Leukocyte Counts with Delayed Cerebral Ischemia in Aneurysmal Subarachnoid Hemorrhage

<i>Background and Purpose:</i> A proinflammatory prothrombotic state may increase the risk of delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage (SAH). We studied the relationship of levels of leukocytes, platelets, C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR) with the development of DCI and with clinical outcome in patients with aneurysmal SAH. <i>Methods:</i> In 125 patients admitted within 72 h after aneurysmal SAH, we dichotomized initial blood levels at their median values and investigated the prediction of DCI with Cox proportional hazard analysis and of poor clinical outcome with logistic regression analysis. We also analyzed concentrations before and after onset of DCI with the paired-samples t test and compared changes with those in patients without DCI. <i>Results:</i> During the development of DCI (unrelated to treatment), patients had a larger increase in counts of platelets (difference 49 × 10⁹/l; 95% CI: 2–98) and leukocytes (difference 2.6 × 10⁹/l; 95% CI: 0.4–5.0) than patients without DCI during the same period. CRP increased during DCI and decreased in patients without DCI (difference 14 mg/l; 95% CI: –29 to 58). ESR increased slightly in both groups (difference 3 mm/h; 95% CI: –15 to 20). None of the determinants at baseline predicted the development of DCI. An increased risk of poor outcome predicted by a high initial leukocyte count (OR 2.5; 95% CI: 1.1–5.7) decreased after adjustment for clinical variables (OR 2.1; 95% CI: 0.8–5.5). <i>Conclusion:</i> Counts of platelets and leukocytes disproportionally increase during the occurrence of DCI after aneurysmal SAH. Drugs with anti-thrombotic or anti-inflammatory properties should be studied for prevention and treatment of DCI.