Management of A2B blood group in a patient for hypothermic cardiopulmonary bypass surgery--a case report.

Abstract

A2 is one of the rare subgroups in the ABO blood group system. Because of the weak antigenic power of A2 subgroup, the hemolytic reaction is not severe under normothermic situations. Under hypothermic conditions, however, such as in cardiac surgery under hypothermic cardiopulmonary bypass (CPB), lethal hemolytic reaction may occur. Autologous blood transfusion helps the anesthesiologist to avoid banked blood and thus avoid unwanted transfusion reactions. The following case report is a 59 yrs old man with an "A2B" negative blood group who underwent CABG under hypothermic CPB (28C, using cold cardioplegia 4C). Following induction, the anesthesiologist drew three units of patient's own blood (1200 cc) and replaced it with the same volume of colloid solution (Acute Normovolemic Hemodilution-ANH). The collected autologous blood was then re-transfused at the end of surgery. With the use of the ANH technique, the patient was successfully managed during hypothermic CPB without the risk of a hemolytic reaction.