In a massive transfusion setting, the patient’s forward and reverse type will reflect the use of group O RBCs and the patient may even fully type as group O, depending on the number of units transfused. Group O RBCs are very precious and in short supply so we need to switch the patient back to his/her own type as soon as feasible. RBCs in additive solution (e.g. SAGM) have only minimal residual plasma so the load of anti-A,B from the O cells is minimal. In my organization, we did not titer ABO hemolysins in blood donors.
Here is my approach:
- Use fresh specimen to perform forward and reverse type
- Check the reverse type: does it show either anti-A and/or anti-B from the group O massive transfusion?
- If anti-A detected, do not give group A RBCs.
- If anti-B detected, do not give group B RBCs.
- If both anti-A and anti-B detected, continue using only group O RBCs.
Some people would recommend performing a full AHG crossmatch using the patient’s current plasma and RBCs of the original ABO type:
- If compatible, return to the original ABO type.
- Otherwise, continue using group O RBCs.
I did NOT do the full AHG crossmatch and had no hemolytic transfusion reactions if the RBCs were compatible with the current reverse type plasma.