Middle cerebral artery velocity changes during transfusion in sickle cell anemia

Abstract

Background and Purpose Sickle cell disease is associated with cerebral hyperemia, which is therapeutically reduced by transfusion; however, the process of transfusion-induced cerebral perfusion changes has heretofore not been observed. Methods We document the acute changes of intracranial arterial velocity in 10 patients (7 with strokes, 3 without) undergoing transfusion therapy using transcranial Doppler ultrasonography. Middle cerebral artery velocities were bilaterally measured every 30 minutes for the duration of transfusion (4 to 5 hours). Regional cerebral blood flow was quantified in 5 of these patients before the transfusion and 24 hours later by the 133Xe technique. Results Velocities in stroke-associated vessels (6433 ± 18.65 cm/s; n=6) were significantly lower than in uninfarcted territories (99.54 ± 27.39 cm/s; n=13), and both types of vessels showed a robust reduction of blood flow velocities during transfusion. The rates of reduction were not significantly different as a function of prior stroke but did correlate with pretransfusion velocities and with the rise in hematocrit (multiple r=.887, P