What drives variability in postoperative cardiac surgery transfusion rates?

Carrinton Mauney; Eric Etchill; Amanda Rea; Clifford Edwin Fonner; Glenn Whitman; Rawn Salenger

doi:10.1016/j.jtcvs.2024.02.004

What drives variability in postoperative cardiac surgery transfusion rates?

J Thorac Cardiovasc Surg. 2024 Feb 7:S0022-5223(24)00109-0. doi: 10.1016/j.jtcvs.2024.02.004. Online ahead of print.

Authors

Carrinton Mauney¹, Eric Etchill², Amanda Rea³, Clifford Edwin Fonner⁴, Glenn Whitman⁵, Rawn Salenger⁶

Affiliations

¹ Johns Hopkins University School of Medicine, Baltimore, Md.
² Department of Surgery, Johns Hopkins Hospital, Baltimore, Md.
³ Division of Cardiac Surgery, Department of Surgery, University of Maryland St Joseph Medical Center, Towson, Md.
⁴ Maryland Cardiac Surgery Quality Initiative, Baltimore, Md.
⁵ Division of Cardiac Surgery, Johns Hopkins Hospital, Baltimore, Md.
⁶ Division of Cardiac Surgery, Department of Surgery, University of Maryland St Joseph Medical Center, Towson, Md; Department of Surgery, University of Maryland School of Medicine, Baltimore, Md. Electronic address: rawnsalenger@umm.edu.

PMID: 38331214
DOI: 10.1016/j.jtcvs.2024.02.004

Abstract

Objective: Wide interhospital variation exists in cardiac surgical postoperative transfusion rates. We aimed to compare transfusion rates at 2 hospitals and identify the institutional practice factors, unrelated to patient or operative characteristics, associated with postoperative transfusion rates.

Methods: Records for adult patients undergoing routine cardiac surgery at 2 hospitals (H and L) from February 2020 to August 2022 were analyzed. Patient and operative characteristics, preoperative and intensive care unit hemoglobin values, and postoperative transfusion rates were compared. Transfusion indication was recorded prospectively. Propensity matching was completed to assess comparability of patient populations.

Results: After propensity matching patients at H and L on age, procedure type, predicted morbidity or mortality, crossclamp time, preoperative hypertension, preoperative heart failure, and preoperative stroke, 2111 patients remained, with similar characteristics except hypertension. Matched results showed no significant differences in mortality, reoperation, or other major outcomes. Hospital H transfused 36% of patients (mean postoperative hemoglobin [Hb] 10.5) with 1483 units of packed red blood cells whereas hospital L transfused 12% of patients (mean postoperative Hb 9.4) with 198 units of packed red blood cells (P < .001). For all patients with a Hb >7.5, hospital H versus L transfused 27% versus 0.9% (P < .001). Hospital L's sole transfusion indication for pretransfusion hemoglobin trigger >7.5 was bleeding versus hospital H, which had multiple indications. When Hb concentration alone was the indication for transfusion, the threshold at hospital H was <7.5 g/dL versus <6 g/dL at hospital L.

Conclusions: Variation in transfusion rates between hospitals H and L resulted from strict adherence at hospital L to a transfusion trigger of <6 g/dL with narrow indications for transfusions above that Hb concentration.

Keywords: cardiac surgery; critical care; patient blood management; perioperative care; transfusion indications.