In vivo comparison study of FDA-approved surface-modifying additives and poly-2-methoxyethylacrylate circuit surfaces coatings during cardiopulmonary bypass

The purpose of this double-blind prospective and randomized study was to examine the effects of surface-modifying additives (SMAs) and poly-2-methoxyethylacrylate (PMEA) circuits on platelet count, platelet function (Sonoclot), postoperative chest tube drainage volume, peri- and postoperative blood product use, extubation time, and intensive care time. Terumo noncoated, Terumo-coated (PMEA), Cobe noncoated, and Cobe coated (SMA) circuits were evaluated to find the most cost-effective way to improve patient outcomes. We aimed to find if an additional charge for a coated CPB circuit would be recovered by reducing other patient costs (blood transfusions, intensive care unit time, and bring back postoperative bleeding). An initial literature review revealed the comparison of PMEA circuits vs. noncoated circuits and SMA circuits vs. noncoated circuits in both adult and porcine models. Both SMA- and PMEA-coated circuits decreased platelet consumption, platelet factor release, and the overall perioperative inflammatory response while on cardiopulmonary bypass (CPB). The question not answered in an initial search was simply, "which coated circuit is best for the patient: SMA or PMEA?" Research comparing the above coated circuits each other was not found. The study was approved by the Institutional Review Board. Thirty patients were scheduled for elective coronary artery bypass grafting and/ or valvular repair or replacement surgery. These 30 patients were randomized as 10 patients to Terumo X-Coating (PMEA surface coating) (CT), 10 patients to Cobe Smart-X coating (SMA surface coating; CC), 5 patients to Terumo noncoated tubing (NCT), and 5 patients to Cobe noncoated tubing (NCC). Informed consent was obtained from each patient before surgery. The data showed no statistically significant relationship between platelet counts, platelet function (Sonoclot), postoperative chest tube drainage volume, peri- and postoperative blood products, intensive care unit time, or total hospital length of stay. Analysis revealed statistically significant clinical associations of extubation time and protamine dose with treatment group. This study provided evidence that SMA- and PMEA-coated circuits do not improve platelet consumption or decrease blood product use for patients undergoing CPB. There was statistical significance with a reduction in extubation time and total protamine requirement needed to return activated clotting time (ACT) to baseline post-CPB. Although the use of SMA and/or PMEA circuits during CPB has clinical benefit to the CPB patient, an additional charge for the specialty circuit may not be realized.