Human errors in manual techniques for ABO/D grouping are associated with potentially lethal outcomes

To review if ABO/D grouping errors are more likely to occur with manual intervention compared to automation.

Human errors in manual pre-transfusion testing may result in ABO/D-incompatible transfusions and catastrophic outcomes. Accurate ABO/D grouping is a critical part of pre-transfusion testing.

This was a retrospective analysis of reports made to Serious Hazards of Transfusion (SHOT) between January 2004 and December 2016 where ABO/D grouping errors led to the transfusion of an incorrect blood component to review if errors are more likely to occur with manual intervention compared to automation.

In 148 of 158 (93%) ABO/D grouping errors, manual intervention took place. In the remaining 10, causes were not reported. No errors occurred with full automation. Interpretation errors occurred in 86 of 148 (58%) and 42 of 148 (28%) transcription errors, and in 20 of 148, wrong or no samples were selected. Of 148 errors, 21 (14%) resulted in ABO-incompatible transfusion, with one death in 2004 due to an interpretation error in a manual ABO group. In 30 of 148 (20%), D-positive red cells were given to D-negative recipients, where three women of child-bearing potential became sensitised and developed anti-D. ABO grouping errors have reduced from 18 of 539 (3%) of total reports analysed in 2004 (3·3%) to 3 of 3091 (0·10%) in 2016.

Where manual testing cannot be avoided, results should be confirmed using automated techniques as soon as possible, and a back-up process should be available 24/7. SHOT data confirm that manual interventions are prone to human error, especially in transcription and interpretation, and demonstrate a continuing need for appropriate serological knowledge and understanding by transfusion laboratory staff to underpin safety provided by automation and information technology (IT).