Intraoperative cell salvage (CS) reduces allogeneic transfusion in cardiac surgery but depletes coagulation factors, potentially causing dose-dependent coagulopathy. Although mechanistic studies suggest hemostatic impairment at higher volumes, nearly all prior clinical studies used binary comparisons, and no dose-response analyses have been performed in cardiac surgery.

This retrospective cohort study included 883 consecutive adult cardiac surgery patients who received CS between January 2023 and August 2025. We evaluated dose-response relationships between CS volume and perioperative transfusion requirements (with identification of discriminative intraoperative thresholds) and postoperative clinical outcomes.

Median CS volume was 0.5 L [0.4–0.7]. CS volume demonstrated strong dose-dependent associations with intraoperative coagulation product transfusion: fresh frozen plasma (OR 6.18), platelets (OR 7.91), and cryoprecipitate (OR 5.25) (all p < 0.001), but not with packed red blood cells. Discriminative thresholds converged at 0.66–0.88 L. Postoperatively, 64.9% received blood products, with only cryoprecipitate remaining associated with CS volume (OR 2.38; p = 0.006). CS volume was associated with increased drainage (β 110 mL; p = 0.023) and intensive care stay (β 1.23 days; p = 0.010). No associations were found with major complications. Complication rates were favorable compared to published benchmarks.

This first continuous dose-response analysis of CS volume in cardiac surgery found no association between CS volume and major complications at typical volumes. However, high postoperative transfusion rates and associations with coagulation product transfusions, drainage, and intensive care stay warrant prospective mechanistic studies to determine optimal management strategies.