Reliability of the pretransfusion bedside compatibility test: association with transfusion practice and training

The utility of a pretransfusion bedside blood compatibility protocol to decrease immunohemolytic accidents has been questioned for years.

The reliability of a standard bedside ABO compatibility test was evaluated with a stratified random sample of 48 nurses who performed agglutination testing by using Bristol cards, interpreted compatibility, and decided whether to transfuse red cells for 12 randomly and blindly selected donor-and-recipient blood sample pairs. An expert judged technical performance and the interpretation of each card.

Erroneous decisions occurred in 18.2 percent of 576 tests, including 12 decisions to transfuse incompatible blood. Errors involved both testing protocols and the interpretation of compatibility. Anti-A and anti-B were detected with 92.8-percent sensitivity and 95.9-percent specificity. The expert judged 17.7 percent of tests to be technically inadequate, most often because of the application of excess blood to the card and a lack of rotation of the card. Testing errors (16.1% of tests) were significantly linked to infrequent transfusion activity by the nursing service, inexperience, and insufficient training. Compatibility misinterpretation occurred in 14.6 percent of the tests and was significantly linked to the nurses' infrequent transfusion activity, inexperience, insufficient training, lack of practical experience, and confusion regarding the use of ABO-compatible but not identical blood.

Bedside pretransfusion compatibility determination should not be considered a reliable supplemental safety procedure in the hands of inexperienced and insufficiently trained operators.