Lessons learned from patient outcomes when lowering hemoglobin transfusion thresholds during COVID-19 blood shortages

This study examines whether patient outcomes were affected when the hemoglobin (Hb) transfusion threshold was lowered by 1 g/dL during COVID-19-related blood shortages.

Outcomes of lowered Hb thresholds (from <7 to <6 g/dL) were defined by 14-month intervals in 2 patient groups (prepandemic [January 2019-February 2020] and pandemic [April 2020-May 2021]). We evaluated patient admissions, pretransfusion (if transfused) or nadir admission (if not transfused) Hb levels between 5.0 and 8.0 g/dL, and total red blood cell (RBC) transfusions during admission (if transfused). Baseline variables and outcomes were selected from electronic health records. Primary COVID-19-related admissions were excluded. Regression analysis was conducted to determine outcomes.

Those in the prepandemic group (1976) and pandemic group (1547) were transfused. Fewer RBCs (2186, vs 3337) were used in the prepandemic group than in the pandemic group, respectively. Those in the prepandemic group had significantly higher rates of hypertension and diabetes as well as more smokers. Significant differences were observed when comparing the number of procedures and incidence of sepsis between the patient groups. Similar patterns were observed for the not transfused and transfused subgroups.

Patient outcomes were not affected after implementing lower Hb pretransfusion thresholds. Although confounding factors were mitigated, some may have been associated with procedures or sepsis. Proactive patient blood management strategies during COVID-19-related blood shortages may include adopting lower Hb thresholds.