Effect of Esketamine Combined with Sufentanil-Based Patient-Controlled Intravenous Analgesia on Postoperative Pain in Elderly Total Hip Arthroplasty Patients: A Three-Arm Randomized Trial

Background: Total hip arthroplasty (THA) is a common procedure for end-stage hip disorders, yet postoperative pain management remains challenging due to opioid-related complications, particularly in elderly patients vulnerable to respiratory depression and delirium. Multimodal analgesia strategies are increasingly prioritized to mitigate these risks. Esketamine, an NMDA receptor antagonist with opioid-sparing and anti-neuroinflammatory properties, shows promise in enhancing analgesia while reducing adverse effects. Preliminary studies suggest its efficacy in lowering postoperative pain and delirium risk, though optimal dosing in elderly THA populations remains unclear. This study aimed to evaluate the analgesic efficacy and safety of different dosages of esketamine combined with sufen-tanil for patient-controlled intravenous analgesia (PCIA) in elderly patients undergoing total hip arthroplasty. Methods: In this randomized, prospective, double-blind trial, 120 elderly patients were randomly divided into three groups: the control group (Group S, <i>n</i> = 40) received sufentanil 2 μg/kg; the experimental group SE1 (<i>n</i> = 40) received sufentanil 1.5 μg/kg combined with esketamine 1 mg/kg; and the experimental group SE2 (<i>n</i> = 40) received sufentanil 1 μg/kg combined with esketamine 2 mg/kg. Primary outcomes included resting and movement-associated Visual Analogue Scale (VAS) scores at 4, 8, 12, 24, and 48 h postoperatively. Secondary outcomes encompassed Ramsay Sedation Scale (RSS) scores, Quality of Recovery-15 (QoR-15) scores at 48 h, time to first walk, the number of patients requiring remedial analgesia, and adverse events (nausea/vomiting, hallucinations, pruritus, delirium, dizziness). Results: The SE1 and SE2 groups demonstrated significantly superior analgesic efficacy compared to the S group across all outcomes. Resting and movement-associated VAS scores were significantly lower in both esketamine-combined groups at all postoperative time points (4, 8, 12, 24, and 48 h; <I>P</I> < 0.05). Sedation levels (Ramsay scores) were dose-dependently enhanced with esketamine. Group SE2 exhibited higher sedation scores than Group S at 24 h (<I>P</I> < 0.01) and 48 h (<I>P</I> < 0.05). The QoR-15 scores at 48 h were significantly higher in Groups SE1 and SE2 compared to Group S (<I>P</I> < 0.001). Time to first walk was shorter in Groups SE1 and SE2 than in Group S (<I>P</I> < 0.001). No significant differences were observed in the requirement for rescue analgesia between groups. Adverse events showed a significant reduction in postoperative delirium (POD) incidence (<I>P</I> < 0.01) and nausea/vomiting (<I>P</I> < 0.05) in Groups SE1 and SE2 compared to Group S, with no significant differences in dizziness, hallucinations, or pruritus. Conclusion: This randomized controlled trial demonstrated that esketamine combined with reduced-dose sufentanil significantly improved postoperative analgesia and recovery outcomes in elderly patients undergoing THA.