The Effect of Standardizing Autologous Prime Techniques in Patients Undergoing Cardiac Surgery with Cardiopulmonary Bypass.

Abstract

Autologous priming (AP) of the extracorporeal circuit has been used as a technique to reduce iatrogenic anemia in patients undergoing cardiac surgery with cardiopulmonary bypass (CPB). The purpose of this study was to review the results of standardizing AP techniques to reduce variation among clinicians and its effect on clinical outcomes. Standardized goal-directed protocols for AP were established by the cardiac team and applied to all adult cardiac surgical patients where CPB was used. Following Institutional Review Board approval, data were analyzed for two sequential groups of patients: Non-standardized AP (NST-AP) and standardized AP (ST-AP). Exclusion criteria included pre-CPB hemodynamic instability and preoperative hematocrit (Hct) values less than 30%. The primary end point was the transfusion of red blood cells (RBCs), whereas secondary end points included Hct change and other perioperative allogeneic blood product transfusions. Data are presented as mean and SD. Of the 192 patients evaluated, 82 were in the NST-AP group and 110 in the ST-AP group. There were no preoperative demographic differences across groups. Total AP volume was lower in the NST-AP group than in the ST-AP patients (486.8 ± 259.6 mL vs. 1,048.2 ± 218.7 mL, p < .001). Whereas pre-CPB Hct values were identical between the groups, the first on-CPB (25.7% ± 4.5% vs. 27.9% ± 4.2%, p < .001), high CPB (27.7% ± 3.5% vs. 29.1% ± 3.6%, p < .008), and first postoperative (32.5% ± 4.0% vs. 34.3% ± 3.9%, p < .003) were all significantly higher in ST-AP patients. Perioperative transfusion rate was higher in NST-AP patients (63.6%) vs. ST-AP (44.6%), p < .01. There was no difference in intraoperative RBC transfusion, but postoperatively, more patients in the NST-AP group received RBCs than those in the ST-AP group (51.2% vs. 28.2%, p < .01). The application of an ST-AP protocol was effective in reducing hemodilution, which was associated within higher Hcts and lower postoperative transfusion rates.