Association of acute normovolemic hemodilution with hematologic inflammatory indices and early clinical outcomes after coronary artery bypass grafting.

Abstract

Background and objectives: Acute normovolemic hemodilution (ANH) is an established patient blood management strategy in cardiac surgery, but its effects on postoperative inflammatory biomarkers remain unclear. In this study, we evaluate the association of ANH with inflammatory indices, lactate-to-albumin ratio, transfusion requirements, and early postoperative outcomes after coronary artery bypass grafting (CABG).

Materials and methods: This retrospective, single-center study included 366 patients who underwent elective isolated CABG with cardiopulmonary bypass. Patients were assigned to an ANH group (n = 169) or a control group (n = 197). Primary outcomes were postoperative neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), neutrophil-to-monocyte-to-lymphocyte ratio (NMLR), and lactate-to-albumin ratio (LAR). Secondary outcomes included blood transfusion, intraoperative bleeding, mechanical ventilation, intensive care unit (ICU) stay and hospital stay, postoperative complications, and infections.

Results: No significant differences were observed in NLR, PLR, or NMLR between the groups. LAR was significantly lower in the ANH group (0.31 ± 0.12 vs. 0.51 ± 0.93, p < 0.001). ANH was also associated with lower blood product utilization, reduced intraoperative bleeding, shorter duration of mechanical ventilation, shorter ICU stay and hospital stay, and lower rates of postoperative complications and infections (all p < 0.05).

Conclusion: In patients undergoing CABG, ANH was associated with improved early postoperative outcomes and a lower LAR but not with significant changes in routine hematologic inflammatory indices. These findings suggest that the benefits of ANH may extend beyond blood conservation.