O– product transfusion, inventory management, and utilization during shortage: the OPTIMUS study

BACKGROUND: Despite conservation strategies, shortages of O- red blood cells (RBCs) occur. The goal of this study was to determine how utilization of O- RBCs can be reduced using age- and location-based O+ substitution for routine transfusions in O- patients during O- shortages. STUDY DESIGN AND METHODS: Recipient age and ABO and D group were obtained for allogeneic RBC transfusions during the 2016 calendar year from 31 participating centers. ABO and D group of each RBC unit was compared to that of the recipient to determine the number of O- RBC units transfused to all patients, the number of RBC units transfused to O- patients, and the number of O- RBC units transfused to O- patients. O- RBC transfusions to O- patients were further analyzed by patient age and location. RESULTS: The fraction of all transfused RBCs that were O- at the participating centers ranged from 3.0% to 13.9%. The percentage of O- RBCs transfused to O- patients ranged from 36.6% to 93.7%. Hospitals differed in the frequency of issuing O- RBCs for O- patient transfusions (55.9%-100%). Relative to current issuing practice, overall use of O- RBCs could have been reduced by 44.5% if O+ units had been given to all O- patients at least 50 years old, 9.9% for all O- patients at least 80 years old, or 8.7% for all O- critical care patients at least 50 years old. CONCLUSION: During O- shortages, O+ switching rules based on the recipient's age and hospital location can be applied for routine transfusions to ensure the availability of O- RBC units for O- females of childbearing age.