For a blood transfusion to be safe, the patient’s and donor’s blood types must be compatible. The chart below allows you to determine compatibility. Keep in mind that, before transfusing begins, the blood product must be cross matched to fully establish donor-recipient compatibility.
ABO blood typing classifies blood into A, B, AB, or O groups according to the presence of major antigens A and B on RBC surfaces, and according to serum antibodies anti-A and anti-B
Remember — if the recipient’s blood type is A, he may receive type A or O blood. If his blood type is B, he may receive type B or O blood. If his blood type is AB, he may receive type A, B, AB, or O blood. If his blood type is O, he may receive only type O blood.
Crossmatching establishes whether donor and recipient blood are compatible and serves as the final check for such compatibility. Lack of agglutination indicates compatibility between donor and recipient blood, which means the blood transfusion can proceed.
Blood is always crossmatched before transfusion, except in extreme emergencies. A complete crossmatch may take 45 minutes to 2 hours, so an incomplete (10-minute) crossmatch may be acceptable in an emergency. An emergency transfusion must proceed with special awareness of the complications that may result from incomplete typing and crossmatching. After crossmatching, compatible units of blood are labeled and a compatibility record is completed.