Incidence and Impact of a Single-Unit Red Blood Cell Transfusion: Analysis of The Society of Thoracic Surgeons Database 2010-2019

BACKGROUND As the adverse effects of blood transfusions are better understood, recommendations support single-unit red blood cell (RBC) transfusions (SRBCT). However, an isolated SRBCT across the entire index admission suggests even the single unit may be avoidable. We sought to identify the characteristics of cardiac surgery patients receiving an isolated SRBCT and analyze the impact on outcomes.METHODS The Society of Thoracic Surgeons Adult Cardiac Surgery Database was queried for the period between January 1, 2010, and December 31, 2019. Patients aged >18 years undergoing isolated coronary artery bypass grafting or isolated aortic valve replacement were included. A total of 2,151,430 encounters were analyzed.RESULTS Of the 847,442 patients (39.3%) receiving any RBC transfusion during their index admission, 206,555 (24.4%) received only 1 unit. Propensity-matching analysis determined SRBCT patients were significantly older (67.26 vs 64.02 years; odds ratio [OR], 1.02; P < .001), female (39.1% vs 17.8%; OR, 1.57; P < .001), non-White (18.2% vs 13.1%; OR, 0.81; P < .001), and had a smaller body surface area (1.94 vs 2.07 m2; OR, 0.20; P < .001). They also had higher mortality (1.4% vs 1.0%, P < .001), stroke (1.7% vs 1.2%, P < .001), prolonged ventilation (6.4% vs 3.4%, P < .001), renal failure (1.8% vs 0.9%, P < .001), and reoperations (1.3% vs. 0.5%, P < .001) than patients who received 0 RBCs.CONCLUSIONS SRBCT is a common occurrence in adult cardiac surgery. This low-volume transfusion is strongly associated with higher morbidity, even after controlling for preoperative risk factors.(Ann Thorac Surg 2023;115:1035-42)(c) 2023 by The Society of Thoracic Surgeons

Automated summary

Isolated single-unit red blood cell transfusions are common in cardiac surgery patients and are associated with higher morbidity.