Abstract
The use of cardiopulmonary bypass (CPB) contributes significantly to intraoperative anemia. The use of a prescriptive circuit that is tailored to the patient size could significantly reduce priming volumes, resulting in less hemodilution. The purpose of this study was to determine whether a prescriptive circuit resulted in decreased hemodilution, reduced blood product usage, and improved outcomes. In total, 204 patients prospectively received the prescriptive protocol between March 2019 and November 2019. This protocol was composed of three circuit sizes: small [body surface area (BSA) ≤ 1.85 m(2)], medium (BSA 1.86-2.30 m(2)), and large (BSA ≥ 2.31 m(2)). Data for CPB and post-bypass transfusions were collected, along with postoperative outcomes. These patients were then 1:2 propensity score matched to 401 patients who were retrospectively reviewed who had undergone cardiac surgery using a one-sized CPB circuit. The prescriptive protocol cohort had more patients with renal disease, whereas the conventional cohort had more history of hypertension. Intraoperative results show the prescriptive circuit had lower mean prime volume and total prime volume after reverse autologous prime (1,084 mL vs. 1,798 mL, p < .0001; 725 mL vs. 1,181 mL, p < .0001). Ultrafiltration was higher in the prescriptive group (872 vs. 645 mL, p < .0001), which likely balanced the increased use of del Nido cardioplegia in the prescriptive group (1,295 vs. 377 mL, p < .0001). The drop in hematocrit (HCT) from baseline was less in the prescriptive group (15.1 ± 4.91 vs. 16.2 ± 4.88, p = .0149), whereas the postoperative HCT was higher (32.79 ± 4.88 vs. 31.68 ± 4.99, p = .0069). Transfusion of packed red cells did not change between the two groups. Implementation of a prescriptive circuit did not reduce on-bypass or intraoperative blood product usage. However, there was a significant reduction in on-bypass hemodilution and increased postoperative HCT.