Anemia and hematoma volume in acute intracerebral hemorrhage

Objective: Anemia increases risk of bleeding complications in the critically ill. In primary intracerebral hemorrhage (ICH), the most fatal type of stroke, outcome is largely dependent on the volume of hemorrhage into the brain. We investigated the relationship between anemia and clinical course of acute ICH. Methods. Six hundred ninety-four consecutive subjects were identified from an ongoing single-center prospective cohort study of nontraumatic ICH during a 6-year period. Anemia was defined according to World Health Organization criteria. Study end points were ICH volume, as measured on the baseline computed tomography scan, and 30-day mortality. Results: Anemia was present in 177 (25.8%) patients on admission. Patients with anemia were older (p = 0.005) and more likely to have coronary artery disease (p < 0.0001). In multivariable analysis, anemia (p = 0.009), lobar location of ICH (p < 0.001), white blood cell count (p < 0.001), and admission diastolic blood pressure (p < 0.001) were associated with larger ICH volume. Although after accounting for ICH volume, none of these variables was a significant predictor of 30-day mortality in multivariable analysis, the size of the marginal reduction in the odds ratio for anemia suggests that it may have a small effect on mortality through mechanisms in addition to ICH volume. Conclusions. Anemia is common in acute ICH and its presence at admission is an independent predictor of larger volume of ICH. Given the central role of ICH volume in outcome, clarification of the mechanisms underlying this relationship may offer novel therapeutic targets for reducing ICH morbidity and mortality. (Crit Care Med 2009; 37:1442-1447)