Effect of preoperative warming combined with dexmedetomidine on postoperative delirium in elderly patients undergoing hip fracture surgery: a randomized controlled trial

Background We evaluated whether preoperative warming combined with dexmedetomidine reduces postoperative delirium (POD) in older patients undergoing hip fracture surgery. Methods This single-blind randomized trial (March–November 2021) enrolled 197 patients aged ≥50 years scheduled for hip fracture surgery. Participants were randomized to warming plus dexmedetomidine (WD), warming alone (W), or control (C). The primary outcome of this manuscript was POD incidence, assessed twice daily from postoperative day (POD) 1 to 3 using the 3D-CAM. Secondary outcomes included delirium days, intraoperative temperature, pain scores (days 1–3), MoCA (days 1 and 3), serum S100β, IL-6, TNF- α, cortisol, and perioperative adverse events. Results Of the 174 randomized patients, 153 completed the study and were included in the final analysis. Postoperative delirium occurred in 49.1% of patients in the control group, 26% in the warming group, and 14% in the warming combined with dexmedetomidine group ( P < 0.001). Delirium duration was significantly shorter in the combined intervention group. Intraoperative body temperatures were consistently higher in the warming and combined groups than in the control group. Postoperative pain scores were significantly lower in the intervention groups. Patients receiving warming combined with dexmedetomidine demonstrated significantly higher postoperative MoCA scores, indicating improved cognitive function. Postoperative inflammatory markers and adverse events were also reduced in the combined group. Conclusions Preoperative warming combined with dexmedetomidine was associated with a lower incidence and shorter duration of POD in older patients undergoing hip fracture surgery. Clinical Trial Registration Chinese Clinical Trial Registry (ChiCTR2100042142) http://www.chictr.org.cn/showproj.aspx?proj=62146 .