Postoperative Delerium Associated with Autologous vs Allogeneic Blood Transfusion in Elderly Hip Arthroplasty Patients Undergoing Combined Spinal-Epidural Anesthesia: A Single-Center Retrospective Study.

BACKGROUND Postoperative delirium (POD) is a clinically significant complication in elderly orthopedic patients that is associated with adverse outcomes and may be differentially affected by transfusion type. However, systematic comparisons in hip arthroplasty (HA) patients remain limited. This study evaluated the effect of 2 types of intraoperative blood transfusions on the incidence of POD in elderly patients undergoing HA. MATERIAL AND METHODS We retrospectively analyzed the medical records of 544 elderly patients (age ≥65 years) who underwent HA with intraoperative transfusion at our orthopedic center between 2018 and April 2025. Baseline characteristics were balanced between groups using inverse probability of treatment weighting (IPTW) derived from propensity score matching. The primary outcome was the incidence of POD, while secondary outcomes included postoperative complications such as deep vein thrombosis and pulmonary infection, as well as the length of hospital stay. RESULTS Following IPTW adjustment, generalized linear regression analysis revealed that the autologous transfusion group had a significantly lower incidence of POD compared to the allogeneic transfusion group (4.2% vs 11.9%; adjusted OR=0.32, 95% CI: 0.13-0.79, P=0.014). No significant differences were found between the groups in secondary outcomes. CONCLUSIONS This study suggests that autologous transfusion is associated with a significantly reduced risk of POD compared to allogeneic transfusion in elderly patients undergoing HA. These results indicate that autologous transfusion may be the best alternative for this patient population, although further large-scale studies are necessary to validate its definitive clinical benefits.