Impact of Pre-bypass Autologous Blood Collection on Blood Transfusion Rates

Pre-bypass acute autologous donation (PAAD) is a method of blood conservation that reduces exposure of blood to the cardiopulmonary bypass (CPB) circuit and may prevent the contact activation of platelets and clotting factors. The purpose of this study was to evaluate the impact of PAAD on product transfusion rates in cardiac surgical patients. This is a retrospective study of patients undergoing cardiac surgery between 2015 and 2017 for either a coronary artery bypass (CABG), valve replacement, or a combined valve/CABG procedure. PAAD was performed by removing blood from the venous line of the bypass circuit immediately before the institution of CPB. The amount of PAAD volume was determined during the surgical time-out. This was based on patient size, baseline hemoglobin, and type of case. Poisson logistic regression was used to determine whether PAAD was a significant predictor for blood product transfusion. After obtaining institutional review board approval, we reviewed 236 records on (n = 154, 65.3%) who received PAAD and (n = 82, 34.7%) with no blood withdrawal before CPB. The median PAAD volume in the PAAD group was 750 mL. Patients undergoing PAAD had a 14.3% red blood cell (RBC) transfusion rate (.27 ± .91 units), and without PAAD, the RBC transfusion rate was 62.2% (1.56 ± 1.79 units). The significant (p < .05) odds ratios (ORs) for RBC transfusion were as follows: baseline hemoglobin .617 (.530-.719), PAAD .998 (.997-.999), CPB time 1.009 (1.003-1.015), age 1.034 (1.013-1.055), and BSA odds ratio (OR) .326 (.124-.857). PAAD could not be used in all patients. However, using the OR in the Poisson logistic regression model, a one-unit reduction in RBC transfusion is predicted for each 500 mL of PAAD. PAAD was also associated with a significant reduction in fresh frozen plasma and platelet transfusion.