The following was my interim policy at HMC for permissible matching and mismatching. This assumes that the patient is not being transfused while in a hypothermic state.
The prohibited options were blocked in the Medinfo Hematos IIG computer system. WAIHA least-incompatible release required physician approval. This protocol did not apply to low-titer group A or low-ABO-titer whole blood units, which were not available at the time.