[A case of Rh incompatible transfusion after use of anti-D immunoglobulin for unexpected intraoperative massive hemorrhage].

A 69-year-old woman with Rh-negative blood type was scheduled for total pelvic exenteration. Despite having prepared suspected amount of blood, we were forced to transfuse Rh-positive blood after use of anti-D immunoglobulin (0.25 mg) for unexpected massive hemorrhage. Although some strategies (blood-withdrawal system, vascular embolization, discontinuation of operation, et al.) for reduction of incompatible transfusion were considered, we fortunately could acquire additional matched blood after transfusion of Rh-positive blood (4 units), and the operation was completed. On postoperative days 1-2, we administered anti-D immunoglobulin (each 0.25 mg) prophylactically. It is reported that 0.02 mg immunoglobulin prevents sensitization against 1 ml transfused red cells. In this case, total dose of immunoglobulin was not enough, but antiD antibody was not detected over 6 months nonetheless. Two reasons were speculated for lack of anti-D anti body; this patient was immune-suppressed for chemoradiation against rectal cancer, and remaining Rh-positive red cells in her body were of small amount because of massive hemorrhage. Anyway, anti-D globulin administration with the aim of complete neutralization against incompatible transfusion is considered impossible, as there are few Rh-negative people in Japan. It is necessary to prepare sufficient matched blood for major surgery of Rh-negative patients, and to consider above-described strategies. Unavoidable Rh incompatible transfusion needs long-term (about 6 months) follow-up based on erythrocyte life-span and time of antibody production.