Impact of Point-of-care Allogeneic Red Blood Cell Washing on Markers of Transfusion-related Respiratory Complications: A Phase II Randomized Clinical Trial

Background: Transfusion-related acute lung injury (TRALI) and transfusion-associated circulatory overload (TACO) are leading causes of transfusion-related morbidity and mortality. Soluble factors in erythrocyte supernatant may increase risk for these complications. The authors hypothesized that point-of-care allogeneic erythrocyte washing may be an effective intervention to mitigate elevations in soluble factors as well as physiologic responses associated with transfusion-associated respiratory complications in the setting of cardiac surgery. Methods: This is a two-center, nonblinded, randomized clinical trial evaluating point-of-care washed versus standard issue allogeneic erythrocyte transfusions administered during or on the day of cardiac surgery. The primary analysis was performed via modified intention to treat. The primary outcomes assessed were changes in intermediate markers of lung injury as well as cardiopulmonary physiologic responses to erythrocyte transfusion. Secondary outcomes included the duration of intensive care unit and hospital stay, durations of mechanical ventilation and oxygen supplementation, presence of TRALI or TACO, and mortality. Results: Among 154 analyzed patients (81 washed, 73 standard issue), the median age was 66 yr, and 77 (50.0%) were women. The median (interquartile range) number of allogeneic erythrocyte units transfused on the day of surgery was 3.0 (2.0 to 5.0) in the washed erythrocyte group and 3.0 (2.0 to 4.0) in the standard issue group (P = 0.13). No between-group differences were identified in any of the assessed recipient lung injury biomarkers (all P values > adjusted alpha). Durations of intensive care unit stay (median [interquartile range], 3.0 [2.0 to 5.0] vs. 3.0 [2.0 to 4.0] days; P = 0.117) and hospital length of stay (12.0 [9.0 to 17.0] vs. 12.0 [9.0 to 17.0] days; P = 0.801) were similar, as were the number of ventilator-free days at day 28 (27.0 [27.0 to 27.0] vs. 27.0 [26.0 to 27.0]; P = 0.699) and oxygen-free days at day 28 (24.0 [19.0 to 26.0] vs. 24.0 [22.0 to 26.0]; P = 0.400). No significant differences were noted in mortality rate or in incidence rates for TRALI, TACO, and acute kidney injury. Conclusions: Among patients undergoing cardiovascular surgery with high risk of erythrocyte transfusion, point-of-care washing of allogeneic erythrocyte transfusions did not mitigate changes in intermediate markers of lung injury or cardiopulmonary physiologic responses to erythrocyte transfusion and was not associated with improved clinical outcomes.