Exchange Transfusions: Blood Volume, Increment Volume, Efficiency

We wish to call attention to an apparently common misconception about the efficiency of exchange transfusions. The mechanics of the procedure are: a substance (bilirubin and/or antibody-coated red cells) is washed out of a compartment (the baby's blood volume) by the removal of a fraction of that compartment and its replacement by an equal volume of diluent (donor blood). This flushing process is repeated many times, usually until the total volume replaced is 2 to 3 times the volume of the compartment itself.