Effects of a multimodality blood conservation schema toward improvement of intraoperative hemoglobin levels and off-pump transfusions in coronary artery bypass graft surgery.

Abstract

Cardiothoracic surgery places significant demands on blood bank resources. Measures aimed at reducing intraoperative hemodilution were initiated as part of a blood conservation program. We initiated a series of measures aimed at reducing hemodilution volume: 1) reduction of intravenous fluid (IVF) volume, 2) reduction of circuit size, and 3) use of autologous priming techniques. All sources and volumes of IVF were obtained from the medical record. Intraoperative hematocrit (Hct) measurements were performed at the following intervals: first in operating room (OR), lowest on-pump, last on-pump, after protamine reversal, and immediately before discharge from OR. Red blood cell (RBC) transfusions were recorded. Intraoperative IVF, Hct levels, and transfusions were analyzed by cardiopulmonary bypass phase (prepump, on-pump, and off-pump), comparing preimplementation and postimplementation periods. Total intraoperative IVF volume was reduced by 973.7 mL (95% confidence interval, 671.6-1275.9 mL; p < 0.001) leading to a mean on-pump Hct improvement of more than 2% (p < 0.004). This contributed to a reduction in off-pump RBC transfusions by 20.6% (p = 0.014). A significant degree of heterogeneity in transfusion practice was noted between anesthesiologists. Blood conservation efforts in cardiac surgery should include efforts aimed at reducing hemodilution. Potential improvements are blunted by variation in transfusion practice.