A Comparison of Efficacy between Low-dose Dexmedetomidine and Propofol for Prophylaxis of Postoperative Delirium in Elderly Patients Undergoing Hip Fracture Surgery: A Randomized Controlled Trial

Aims and background: The efficacy of dexmedetomidine and propofol in preventing postoperative delirium is controversial. This study aims to evaluate the efficacy of dexmedetomidine and propofol for preventing postoperative delirium in extubated elderly patients undergoing hip fracture surgery. Materials and methods: This randomized controlled trial included participants undergoing hip fracture surgery. Participants were randomly assigned to receive dexmedetomidine, propofol, or placebo intravenously during intensive care unit (ICU) admission (8 p.m. to 6 a.m.). The drug dosages were adjusted to achieve the Richmond Agitation Sedation Scale (RASS) of 0 to -1. The primary outcome was postoperative delirium. The secondary outcomes were postoperative complications, fentanyl consumption, and length of hospital stay. Results: 108 participants were enrolled (n = 36 per group). Postoperative delirium incidences were 8.3%, 22.2%, and 5.6% in the dexmedetomidine, propofol, and placebo groups, respectively. The hazard ratios of dexmedetomidine and propofol compared with placebo were 1.49 (95% CI, 0.25, 8.95; p = 0.66) and 4.18 (95% CI, 0.88, 19.69; p = 0.07). The incidence of bradycardia was higher in the dexmedetomidine group compared with others (13.9%; p = 0.01) but not for hypotension (8.3%; p = 0.32). The median length of hospital stays (8 days, IQR: 7, 11) and fentanyl consumption (240 mu g, IQR: 120, 400) were not different among groups. Conclusion: This study did not successfully demonstrate the impact of nocturnal low-dose dexmedetomidine and propofol in preventing postoperative delirium among elderly patients undergoing hip fracture surgery. While not statistically significant, it is noteworthy that propofol exhibited a comparatively higher delirium rate.