Isovolumetric partial exchange transfusion in the management of sickle cell disease in pregnancy. II. Simplified ambulatory technique.

A simple technique is presented for determining the volume of blood to be exchanged in an isovolumetric partial exchange transfusion in order to achieve a desired final hematocrit or desired final percentage of normal hemoglobin. Experience from 16 exchange transfusions in 10 obstetric patients is used to improve the estimate of specific blood volume and, hence, the accuracy of the technique. A detailed protocol for this simple outpatient procedure is presented.