Processed residual pump blood in cardiac surgery: the Processed Residual Blood in Cardiac surgery trial

BACKGROUND: Processing residual cardiopulmonary bypass (CPB) volume via ultrafiltration may improve hemostasis and reduce transfusion through clearing activated complement, activated coagulation components, and proinflammatory cytokines. We sought to establish if processing residual CPB volume with ultrafiltration reduces homologous blood transfusion and bleeding. STUDY DESIGN AND METHODS: Adult patients undergoing isolated coronary artery bypass grafting (CABG) surgery were randomly assigned to receive processed (n = 99) or unprocessed (control; n = 98) residual CPB volume in this single-center randomized controlled trial. The intensive care unit team, patients, and assessors were blinded to treatment assignment and a transfusion protocol was followed. Surgeons were permitted to use retrograde autologous priming to minimize crystalloid pump prime. RESULTS: The processed study bag was of a smaller volume (280 [0, 550] mL vs. 590 [215, 726] mL; p < 0.01) but a higher hematocrit (29% [0%, 34%] vs. 23% [20%, 25%]; p < 0.01) than control. The rate of transfusion with homologous blood was 39% in both groups (p = 0.92). There was no difference in the volume transfused (processed 323 ± 585 mL vs. control 276 ± 520 mL; p = 0.56). There was also no difference in the proportion of patients transfused with any blood product (processed 44% vs. control 45%; p = 0.95) or in the volume of chest tube output (processed 600 [500, 940] mL vs. control 670 [490, 932] mL; p = 0.62). CONCLUSION: Ultrafiltration of residual CPB volume in adults undergoing isolated CABG surgery does not reduce the need for transfusion or bleeding.