An anesthesiologist at an academic medical center in Quebec comments that it is not uncommon for trauma or massively bleeding patients to receive type O Rh negative RBCs urgently, prior to a formal crossmatch. However, he points out that opinions differ as to selection of products subsequently, when typing shows that the patient is not type O.

He is interested to learn the practice followed by others regarding the use of type-specific donor RBCs for type A, B or AB patients who have received uncrossmatched type O RBCs in urgent situations. He is specifically interested in knowing if the practice is influenced by the number of type O RBC units that a patient has already received (1-2 vs more than 2).

Editor's comment: An earlier discussion on this forum addresses the hemostatic problems associated with massive transfusion, and may be of interest to visitors.

The following responses have been received.

ADDENDA Nov. 9, 2004

1. A transfusion medicine physician at an academic medical center in Central Ohio that "bleeds scarlet and gray" comments that their policy is to change to the patient's true blood type as soon as they can type a specimen. The patient may have received as many as 6-10 group O Rh negative RBC units. With the present day use of additive solution red blood cells (AS-RBC), there is little plasma is in each unit. She is of the opinion that the old concern was whole blood, with its group O plasma incompatible with the patient's red blood cells, which could lead to incompatible crossmatches with the patient's own blood type. This rarely happens today with AS-RBC units. On the other hand, they are more likely to face this ABO incompatibility issue with the use of ABO-incompatible platelets. And even then, they rarely see positive DAT, anemia, and typing discrepancies unless several doses (>2000 mL) of ABO-incompatible platelets have been transfused. They also switch to the patient's own blood type to conserve group O Rh negative RBCs for patients who are truly group O Rh negative.

Editor's comment: Visitors are encouraged to review the earlier discussion on the risks of ABO-incompatible plasma when administering platelet transfusions.

2. A colleague in Louisiana at a facility with a level 1 trauma center states that it is their policy to issue up to 4 units of group O Rh negative red cells to a patient who needs emergency transfusions before their true blood type can be determined. If the patient needs more than 4 units of group O Rh negative uncrossmatched blood before they know the patient's true ABO/Rh, they would switch to group O Rh positive RBCs. An exception to switching to Rh positive RBCs might be made, IF their group O Rh negative supply was sufficient and the bleeding patient was a young female, depending on the kind of trauma and the expected usage. They handle their pediatric and neonatal cases on a case by case basis. The aforementioned policy has been approved by their Trauma Committee. If they determine an ADULT patient's true blood type before 8 units of group O RBCs are given, they would switch to the patient's true blood type. If the ADULT patient receives 8 or more units of group O RBCs, they maintain the patient with group O RBCs until it can be determined that there is no passive anti-A or anti-B in the patient's circulation.

3. A transfusion medicine physician in Australia reports that switching to group specific RBCs after using group O Rh negative RBCs in an emergency is a situation that occurs fairly frequently at his hospital [a level 1 trauma center]. Since they use additive solution RBCs the volume of plasma infused with each unit is relatively small. Hence switching to group specific RBCs is not the problem that it once was when whole blood was being used. Their current policy for adults is to switch to group specific RBCs if <10 units of group O Rh negative RBCs or <2 units of group O Rh negative whole blood have been transfused. For patients who receive >10 units of group O Rh negative RBCs, a fresh patient sample is required on which they screen for anti-A and/or B by indirect antiglobulin test against A and B cells. If this screen is negative they switch the patient to group specific RBCs. He reports good success with the above approach for many years, without any observed problems.

4. A transfusion medicine physician in the Pacific Northwest is of the opinion that the most responsible use of the community supply of group O blood is to switch the patient to their own blood group as soon as possible. The surgeons at his trauma hospital draw a sample for ABO/Rh testing as early into the resuscitation process as possible. The transfusion service will provide ABO/Rh group specific uncrossmatched red cells until the crossmatch testing is complete. With so little plasma in the AS-preserved red cell units, one would have to be transfused with many (?15-20) group O red cells before being concerned that one has 'converted' the patient's reverse group to O.

ADDENDA Nov. 23, 2004

5. Stephen Apfelroth, M.D., Ph.D. Director, Blood Bank Jacobi Medical Center at the Albert Einstein College of Medicine, Bronx, NY (attribution used with permission) is of the opinion that concerns over switching to group specific RBCs after a patient has received several units of group O RBCs stem from statements such as can be found in a popular textbook like the 4th edition of "Clinical Anesthesia" published by Lippincott, which warn against switching to group specific RBCs if more than two units of group O RBCs have been given. Dr. Apfelroth reports that he has had direct correspondence with one of the editors of the aforementioned book. Interestingly, the transfusion policy at the editor's Ivy League institution is much more liberal, prohibiting a switch from group O RBCs to the native ABO group when up to 10 to 12 units of group O RBCs have been received. Furthermore, Dr. Apfelroth also notes that platelet transfusions have not been of similar concern to anesthesiologists despite the fact that a group O platelet dose can have more ABO incompatible plasma than 9 or 10 units of group O RBCs. The textbook editor reportedly told Dr. Apfelroth that the authors of the chapter in question would be informed, and that the authors would be asked to make appropriate modifications in the future.

ADDENDA Nov. 29, 2004

6. A transfusion medicine physician in Houston reports that her hospital has a Level 1 Trauma center where their policy is to switch a patient from group O RBCs to group specific RBCs as soon as it can be determined what the patient's native ABO is, provided the patient has not received more than 15 group O RBC units. The Houston physician reports having done follow-up for recipients who received uncrossmatch group O RBCs in an emergency by doing a direct antiglbobulin test (DAT) and by examining post-transfusion patient samples for hemolysis. She reports finding no evidence of either a positive DAT or hemolysis due to the infusion of the residual anti-A and anti-B which can be in uncrossmatched group O RBCs.

7. David Orchard, M.T. (ASCP) of St. Vincent Hospital Blood Bank in Green Bay, Wisconsin (attribution used with permission) has graciously provided procedures in use at his facility (MS Word file) that address when they will switch from group O to group specific RBCs upon learning the true blood group of a patient.

ADDENDA Dec. 12, 2007

8. Editors' Note: The 5th edition of the textbook "Clinical Anesthesia" (referred to in #5, above) has updated the discussion about out of group blood to read:

"If a non group O patient receives a large volume of group O red cells, the combined amount of anti-A and/or anti-B present in the small amounts in the residual plasma [in] each PRBC unit may react with the patient's own A, B, or AB red calls and cause some hemolysis. For this reason, non group O patients who have received group O red cells approximating one patient blood volume (10 to 12 units) during the period of acute blood loss should not be switched back to their own ABO group unless testing has been performed to confirm that significant titers of anti-A or anti-B antibodies are not present."

We appreciate the responsiveness of the authors and editors of "Clinical Anesthesia" to our readers' concerns.

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