Randomized clinical trials of hemodilution in acute ischemic stroke.

The effects of hemodilution in acute ischemic stroke have been investigated, first in a single-center, then in a multicenter trial. Patients with hematocrit levels of 38-50% were randomized, within 48 h of onset of symptoms, to treatment with repeated venesections (total 250-1000 ml) and concomitant dextran 40 administration, or to a control group. The single-center study, performed in a research-oriented stroke unit, involved 102 patients. Case fatality rate was not grossly affected by hemodilution. In survivors, hemodilution improved neurological outcome. More hemodiluted patients were independent in walking and more were at home 3 months after the stroke. The ensuing multicenter trial involved 383 patients in 15 Scandinavian centers. Three-month case fatality rate was 16% in hemodiluted and 12% in control patients. Neurological scoring and ADL performance at 3 months was not improved by hemodilution. No subgroup with beneficial effects was discerned. It is concluded that the present standardized hemodilution regime cannot be recommended for general use in patients with ischemic stroke.