A transfusion medicine physician in Alabama is interested to learn how others handle the need for transfusing Rh-positive RBCs to patients that are Rh-negative in times of severe shortage. At her tertiary care university hospital they do not collect blood on site and have experienced severe RBC shortages from time to time that force them to use Rh-positive RBCs for bleeding Rh-negative patients, except for girls and women of child-bearing age. At the inquiring colleague’s hospital the need to switch Rh types is discussed on a case by case basis with the ordering physician, and the switch from Rh-negative to Rh-positive RBCs only occurs if there is agreement by the treating physician to accept an Rh-positive RBC unit. An anesthesiologist at the inquiring colleague's institution is wondering what else should be done to educate physicians who might need to approve the transfusion of Rh-positive RBCs to Rh-negative patients, so that they can alert patients of the potential risks of developing anti-D. For example, does any Transfusion Medicine medical director issue a letter to the medical staff explaining the risks of using Rh-positive RBCs for an Rh-negative patient?

Editor's note: The following links may provide additional information that is germane to this discussion:

• Policies for Ensuring An Adequate Supply of O Rh Negative Blood in Emergencies
• How important is it to avoid Rh mismatched platelets for Rh-negative female neonates?

ADDENDA Sept. 8, 2003

The following responses have been received.

1. A transfusion medicine physician in Detroit reports that for several years their hospital has had a standing policy of providing group O Rh positive RBCs as the initial "trauma blood" to all males and to females over age 50, who require emergency transfusion when coming through the emergency room. This policy has been approved by their Transfusion Committee. In the event of such emergency transfusion, as soon as the laboratory receives a sample from the ER for testing, the patient's ABO/Rh is determined and an antibody screen and crossmatching is performed. If either is positive, the ER is immediately notified so that they have the option of returning uncrossmatched blood pending antibody identification. The Detroit physician reports that in their experience, more than 90% of their ER patients are Rh positive. Females under age 50 receive group O Rh negative RBCs for their initial "trauma blood" in the emergency room, but those women may also be switched to group O Rh positive RBCs if the supply situation warrants it. In non-emergency room cases in which large quantities of group O Rh negative blood are being utilized (such as by a surgical patient), any decision to switch from using Rh negative to Rh positive blood during periods of shortage are made on an individual basis in concert with the treating physician after an assessment of anticipated further need, patient's clinical condition, etc. The Detroit physician comments that at her facility she has noticed that the prospect of the patient being switched to Rh positive blood can sometimes suddenly cause excessive bleeding to cease. She refers readers to following 2 references that address the risks of D alloimmunization after Rh positive transfusion in an Rh negative patient (which are less than most physicians believe)

• Frohn C, et al. Probability of anti-D development in D- patients receiving D+ RBCs. Transfusion 2003;43893-8.
• Schmidt PJ, et al. Use of Rh positive blood in emergency situations. Surgery, Gynecology & Obstetrics 1988;167229-33.
  

Finally, the Detroit physician also relates to physicians that, in an emergency situation, although she herself is under 50 and Rh negative (type A), she would rather receive Rh positive RBCs than risk morbidity or death from undertransfusion or delayed transfusion!

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Ira A. Shulman, MD
CBBS e-Network Forum Editor & Moderator