Quantifying Harms Associated With Red Cell ABO Incompatible Blood Transfusion: A Systematic Review of the UK SHOT Literature

ABO-incompatible (ABOi) red blood cell (RBC) transfusions can lead to severe clinical consequences, including patient death. Electronic systems, such as Bedside Electronic Transfusion Checks (BETC), have been developed to lower the risk of these serious incidents occurring due to errors in patient identification at the bedside; however, the benefits for patients have not yet been fully quantified. To address this gap, we aimed to quantify the harms (ie, morbidity and mortality) associated with ABOi RBC transfusions in the UK, enabling us to better understand the benefits of BETC in preventing these events for patients.

Twenty-seven years of published UK hemovigilance data from cases submitted to Serious Hazards of Transfusion (SHOT), including reports from 1996 to 2023 were reviewed using systematic review methodology by 2 independent reviewers. Data was collated into a Microsoft Excel database for further analysis. The data were analyzed to determine the number of reports of ABOi RBC transfusion and the rate of mortality/morbidity associated with these events. Morbidity was defined as hemolytic transfusion reaction (acute and delayed), any organ injury, extended length of hospital stays, the requirement for mechanical ventilation and ITU admission (including critical care units), and any other adverse events as reported in each case.

Over 27 years (1996-2023), 55.3 million RBC units were issued in the UK, with 368 ABO-incompatible (ABOi) transfusions, equating to 0.67 per 100,000 transfusions. Clinical errors accounted for 53.3% of the observed ABOi transfusions (0.36 per 100,000), primarily occurring during administration (0.16 per 100,000), blood collection (0.10 per 100,000), and sample collection (0.07 per 100,000). Laboratory errors made up for 13.6% of the observed ABOi transfusions (0.09 per 100,000), predominantly being a consequence of errors in pretransfusion testing (0.06 per 100,000). Mortality among the observed ABOi transfusions was 6.3% (0.04 per 100,000), with major morbidity at 23.9% (0.16 per 100,000), which includes ICU admissions (0.03 per 100,000) and hemolytic reactions (0.05 per 100,000).

While ABOi RBC transfusions have become rare in the UK, they are associated with significant short-term morbidity and mortality. Early SHOT reports lacked standardization and provide limited data on patient outcome. When patient outcome was reported, it was limited to short-term outcomes immediately post ABOi transfusions. No data was reported on longer -term patient outcomes limiting the ability to provide long-term outcome assessment. Enhancing hemovigilance practices is essential to reducing ABOi risks. National hemovigilance schemes worldwide need to harmonize/standardize the reporting of short-term and long-term outcome data collection for ABOi RBC transfusions so we can better understand the risk and burden of these events on patients.