Abstract / Summary
Cardiac surgery with cardiopulmonary bypass (CPB) is associated with perioperative blood loss, coagulation disturbances, and increased allogeneic red blood cell (RBC) transfusion requirements. This study evaluated whether postoperative reinfusion of residual CPB circuit blood reduces allogeneic RBC transfusion requirements and affects rotational thromboelastometry (ROTEM) parameters. This single-center, two-arm, parallel-group randomized controlled trial enrolled 60 adults aged 18–70 years undergoing elective coronary artery bypass grafting with CPB at Atatürk University Research Hospital from April 2023 to April 2024. Participants were allocated 1:1 by computer-generated simple randomization to residual CPB circuit blood reinfusion ( n = 30) or no reinfusion ( n = 30). Patients, clinicians responsible for postoperative transfusion decisions, outcome assessors, and data analysts were blinded to group allocation. The primary outcome was allogeneic RBC transfusion requirement from the end of surgery until intensive care unit (ICU) discharge. Secondary outcomes included ROTEM parameters, chest tube drainage during the prespecified periods (0–4 h, cumulative 0–24 h, 24–48 h, and 48 h to ICU discharge), ICU length of stay, laboratory values, and in-hospital complications. Continuous variables were compared using Student’s t test or the Mann–Whitney U test, and categorical variables using the chi-square test or Fisher’s exact test, as appropriate. P values for the 20 between-group ROTEM comparisons were adjusted using Holm’s step-down procedure. The study was funded by Atatürk University Scientific Research Project Coordinator (TTU-2023-12558). All 60 patients completed follow-up and were analyzed (30 per group). The median volume of circuit-derived autologous blood reinfused was 625 [505–875] mL. RBC transfusion requirement was lower in the reinfusion group than in the control group (1 [0–2] vs. 2 [1–3] units; p = 0.030). After Holm adjustment for 20 ROTEM comparisons, FIBTEM clotting time was the only parameter that remained significantly different between groups and was longer in the reinfusion group (71 [66–77] vs. 65 [61–67] s; unadjusted p = 0.001; adjusted p = 0.020). The INTEM/HEPTEM clotting time ratio was higher in the reinfusion group (1.08 [1.03–1.09] vs. 1.02 [1.01–1.03]; unadjusted p = 0.010), but this difference was not statistically significant after adjustment (adjusted p = 0.190). Chest tube drainage during the prespecified periods (0–4 h, cumulative 0–24 h, 24–48 h, and 48 h to ICU discharge) and ICU length of stay were similar between groups. Postoperative reinfusion of residual CPB circuit blood was associated with lower allogeneic RBC transfusion requirements in this small trial. No between-group difference in chest tube drainage was detected, and no re-exploration for bleeding occurred in either group. FIBTEM clotting time was longer in the reinfusion group; the clinical significance of this finding is uncertain. Larger studies are needed to confirm the transfusion findings and assess potential harms. ClinicalTrials.gov, NCT06824753; retrospectively registered on 11 October 2024.