Efficacy of the “Head-Up Position” in Returning Cardiopulmonary Bypass Blood to the Patient and Reducing the Required Blood Transfusion: A Randomized Trial

Background: All intraoperative strategies that may assist an anesthesiologist with lowering the blood transfusion rate must be considered. We assessed the efficacy of the 30° head-up position at the end of cardiopulmonary bypass (CPB) in returning CPB reservoir blood to patients, reducing the transfusion rate, and conferring hemodynamic stability after the transfer of patients to the intensive care unit (ICU). Methods: In a single-center clinical trial, 88 adult patients undergoing elective isolated coronary artery bypass graft surgery were randomly allocated to the head-up group (n=44), in which the 30° head-up position was applied during separation from CPB, and the supine group (n=44), in which weaning from CPB was performed in the supine position. All the patients had left ventricular ejection fractions > 35%. The primary end point was the returned volume of filtered CPB blood to the patients. The secondary outcome measures were intraoperative and early postoperative hemodynamic parameters. Additionally, blood products transfused during surgery and in the 1st 6 hours following ICU admission were recorded. Results: There were no statistically significant differences in intraoperative and early postoperative hemodynamics between the 2 groups except in the returned blood volume to the patients after separation from CPB (714 ± 99 mL in the head-up position group vs 285 ± 78 mL in the supine group; P = 0.0001). There were no significant differences between the 2 groups regarding the transfused blood products during surgery and the 1st 6 hours following ICU admission. Conclusions: Using the 30° head-up position at the end of CPB conferred a higher return of blood to the patients but did not significantly reduce postoperative transfusion.