What is a requirement for computer crossmatch?

The requirement for a computer crossmatch is that two identical ABO typing interpretations must be made on the recipient. This is crucial for ensuring that the blood type is accurately determined and reduces the risk of compatibility issues during transfusions. In blood transfusion practices, confirming the ABO blood group is essential because mismatching can lead to serious, potentially life-threatening reactions.

Having two identical interpretations helps to eliminate human error or variability in testing, thereby reinforcing the accuracy of the blood type determination. This redundancy in the ABO typing process ensures that any discrepancies can be identified and resolved before proceeding with a transfusion, which is critical for patient safety.

In contrast, relying solely on historical records or only performing the test once does not provide the robust verification needed in transfusion practices. Moreover, recent samples alone may not capture any changes in the patient's blood type, which can occur due to various medical conditions or treatments. Thus, the two identical interpretations serve as a safeguard that maintains high standards for patient care in transfusion medicine.