Errors in interpreting the pretransfusion bedside compatibility test: an experimental study

Analysis of reports of incidents, involving ABO incompatibility suggests that the main problem is poor interpretation of the pretransfusion bedside compatibility test (PBCT). We studied sources of error as experienced by nurses as to the blood groups of donor blood and of the recipient.

According to their seniority in the profession and on the ward, 48 nurses were randomly selected from four transfusion sectors of the University Hospital of Grenoble, France. Each nurse interpreted 24 photos of PBCTs, including some with procedural irregularities, and was asked to assess the compatibility of the blood types of the donor and the recipient. At random, half the nurses were provided with a diagram to facilitate interpretation.

The overall frequency of errors was 39.8%. Errors were fewer when the tests were interpreted as compatible (7.3%) or incompatible (6.3%), and when the nurse had been in the profession between 3 and 5 years and in the ward less than 3 years (25.5%), or worked in hematology (34.7%) or anesthesia (36.5%). Use of the diagram limited the number of errors, provided the test was interpretable (22.2%).

PBCTs cannot be considered a valid safety procedure. We need other, more effective methods to reduce the risk of incompatibility accidents.