Exchange blood transfusion compared with simple transfusion for first overt stroke is associated with a lower risk of subsequent stroke: a retrospective cohort study of 137 children with sickle cell anemia.

A retrospective cohort study of children with sickle cell anemia (SCA) and strokes was used to test the hypothesis that exchange transfusion at the time of stroke presentation more effectively prevents second strokes than does simple transfusion. Children receiving simple transfusion had a 5-fold greater relative risk (95% confidence interval = 1.3 to 18.6) of second stroke than those receiving exchange transfusion.