Re‐evaluating treatment thresholds in patient blood management: Female patients experience more perioperative anaemia and higher transfusion rates in major elective surgery

Background and Objectives By optimizing erythropoiesis, patient blood management (PBM) programmes can reduce transfusions, lower mortality and provide cost‐effective care. While definitions of anaemia have historically varied by sex, for the purposes of PBM, anaemia is defined as a haemoglobin <130 g/L. Our objective was to describe whether perioperative anaemia and transfusion rates in the PBM setting vary by sex. Materials and Methods We conducted a retrospective study of the Ontario Nurse Transfusion Coordinators Program (ONTraC) database from 2018 to 2022. ONTraC collects data from 25 Ontario hospitals which together account for >70% of Ontario's provincial blood use (~400,000 units per year). We collected data on patients undergoing elective isolated coronary artery bypass graft surgery (CABG), open heart valve replacement, CABG plus valve replacement, single‐knee arthroplasty and single‐hip arthroplasty. Results From 2018 to 2022, 17,700 patients were included in the ONTraC program; 47% were females ( N = 8376). Across almost all years and procedures, females were found to have a significantly lower pre‐operative, nadir and discharge haemoglobin as compared with males, irrespective of PBM interventions. Transfusion rates were significantly higher for females; this was most pronounced in cardiac surgery. Conclusion Females experienced more perioperative anaemia and higher transfusion rates. Historic sex‐specific definitions of anaemia may contribute to a greater tolerance of anaemia in females. Prioritizing females for multimodal PBM and consistently achieving a pre‐operative haemoglobin >130 g/L may reduce the amount of red blood cell (RBC) transfusions that female patients receive.