Group O Rh D-negative (O-negative) blood is a limited resource with disproportionately greater demand for use relative to available Canadian donors. The National Advisory Committee on Blood and Blood Products (NAC) 2016 best practice recommendations define O-negative RBC use as mandatory for O-negative women under age 45, O-negative persons with anti-D alloantibodies, and emergencies in women under age 45 of unknown blood type. Locally, age 50 is the cut-off for women of childbearing potential. We completed a quality assurance audit of O-negative RBC transfusions in Royal University Hospital (RUH) to assess guideline adherence and evaluate the impact of our local age cut-off on O-negative utilization.
A retrospective chart review included all units of O-negative RBC transfused to inpatients at RUH during January-December 2018. Data variables collected included patient age, sex, blood group, transfusion indication, and pre- and post-transfusion hemoglobin. Outpatients and incomplete charts were excluded.
Data analysis included 405 units of O-negative blood. 33 units (8.1%) were transfused for mandatory indications. Generally acceptable indications accounted for 155 units (38.3%), including 22 units (5.4%) to infants, and 133 units (32.8%) to O-negative patients in non-massive transfusions. Conversely, 53 units (13.1%) were transfused to prevent unit expiry and 94 emergency units (23.2%) were transfused to men and women over 45. Only 2 units (0.5%) were transfused to women aged 46-49. Transfusion indication was not documented for 70 units (17.3%).
Our data shows that 46.4% of O-negative RBC were administered appropriately per NAC guidelines. Minimal O-negative RBC transfused to women aged 46-49 justifies our current policy for women of childbearing potential. 36.3% of O-negative units were transfused for likely unacceptable indications, including 13% approaching expiry. Local policies should be re-evaluated to reduce emergency uncrossmatched RBC issued to men and women over age 50.