Comparison of Two Different Red Blood Cell Transfusion Thresholds on Short-Term Clinical Outcomes of Patients Undergoing Aortic Surgery With Deep Hypothermic Circulatory Arrest.

Objective: Patients undergoing aortic surgery with deep hypothermic circulatory arrest (DHCA) usually are associated with a high rate of allogeneic blood transfusion, and their red blood cell (RBC) transfusion threshold is unclear and controversial. The purpose of this study was to explore whether a restrictive transfusion threshold was as effective as a liberal transfusion threshold for patients undergoing aortic surgery with DHCA.

Design: Retrospective, controlled study.

Setting: National Center for Cardiovascular Diseases and a university hospital, Beijing, China.

Participants: The study comprised 74 patients undergoing aortic surgery with DHCA from January 1 to December 31, 2014.

Interventions: Patients were divided retrospectively into the following 2 groups according to the RBC transfusion thresholds-the restrictive group received allogeneic RBC transfusion if the hemoglobin (Hb) level of the patient fell below 8 g/dL during the surgery, and in the liberal group the hemoglobin threshold for allogeneic transfusion was 10 g/dL.

Measurements And Main Results: Data on patient demographics, procedure characteristics, allogeneic blood use, and postoperational morbidity and mortality were collected and analyzed. In total, the restrictive group required fewer perioperative transfusions of RBCs (3.9±4.8 v 8.5±6.9 units, p = 0.001) and platelets (1.9±0.8 v 2.6±1.0 units, p = 0.003) compared with the liberal group. Postoperative mortality and complications, including 30-day mortality and bleeding requiring re-exploration, did not differ significantly between the 2 groups.

Conclusions: For patients undergoing aortic surgery with DHCA, a restrictive RBC transfusion threshold (Hb<8 g per deciliter) may be as effective as a liberal RBC transfusion threshold (Hb<10 g per deciliter) during the surgery, with similar short-term clinical outcomes and less allogeneic transfusion.