Authors: Zhu, Youzhuang et al.
Anesthesiology October 2025 | DOI: 10.1097/ALN.0000000000005800
This randomized controlled trial evaluated whether S-ketamine can reduce postoperative delirium (POD) in elderly patients undergoing total hip or knee arthroplasty under neuraxial anesthesia. The study enrolled 372 patients between November 2023 and October 2024 at a high-volume arthroplasty center with standardized perioperative care protocols. Participants were randomized to receive either intravenous S-ketamine or placebo and were monitored for three days postoperatively for delirium and other outcomes.
Within three days after surgery, POD occurred in 8.1% of patients receiving S-ketamine compared with 20.4% in the placebo group (adjusted OR 0.29; 95% CI 0.14–0.63; P = 0.002). Patients in the S-ketamine group also reported lower pain scores during postoperative day 1 rehabilitation and required fewer rescue analgesics. However, mild psychomimetic side effects—including hallucinations, dizziness, and nightmares—were more frequent in the S-ketamine group, although no major safety concerns or differences in other complications were observed.
The authors conclude that perioperative S-ketamine, when used with neuraxial anesthesia rather than general anesthesia, significantly reduces the risk of postoperative delirium in elderly arthroplasty patients while providing effective analgesia. They note that the generalizability of these findings may be limited by the single-center design and the specific perioperative protocols used.
What You Should Know
-
S-ketamine lowers the incidence of postoperative delirium by roughly 70% in elderly arthroplasty patients receiving neuraxial anesthesia.
-
Benefits include reduced early postoperative pain and decreased opioid requirements.
-
Mild transient side effects (hallucinations or dizziness) may occur but are generally self-limited.
-
Findings suggest that avoiding general anesthesia enhances the neuroprotective potential of S-ketamine in older adults.
Thank you for allowing us to use this article from Anesthesiology.