Background: The effects of perioperative ketamine and esketamine on postoperative nausea and vomiting (PONV) remain unclear. This study aimed to clarify their impact on PONV and related adverse events. Methods: We performed a meta-analysis of randomized controlled trials and observational studies comparing ketamine or esketamine with control agents. The primary outcome was a pooled analysis of PONV and nausea-only data. PONV, postoperative nausea (PON), and postoperative vomiting (POV) were also analyzed separately. Subgroup analyses were conducted by comparator type (placebo, opioid, or non-opioid) and dose categories. Meta-regression was used to assess dose-response relationships. Results: Fifty-five studies (n = 6676) were included. Ketamine and esketamine did not significantly reduce the incidence of pooled PONV risk (risk ratio [RR]: 0.95, 95% CI [0.87–1.04], P = 0.274). No benefit was found versus placebo. Compared with opioids, PONV was reduced (RR = 0.50, 95% CI [0.32–0.77], P = 0.002), but not in the pooled analysis (RR = 0.69, 95% CI [0.43–1.08], P = 0.107). Conversely, compared with non-opioid controls, ketamine/esketamine increased the pooled PONV risk (RR = 1.46, 95% CI [1.03–2.05], P = 0.032). No significant dose-response relationship was found. Both agents increased hallucinations (RR = 1.73, 95% CI [1.35–2.20], P = 0.0002) and drowsiness (RR = 2.18, 95% CI [1.13–4.21], P = 0.024). Conclusions Ketamine and esketamine did not significantly reduce PONV overall. While they showed benefits compared with opioid-based regimens, they may be less effective than non-opioid adjuvants. However, their neuropsychiatric and sedative risks warrant cautious use.

Background: In sugammadex-induced anaphylaxis, sugammadex and/or sugammadex-rocuronium complex have possible allergenic epitope. Case: We report a case of sugammadex-induced anaphylaxis during general anesthesia in a 60-year-old male undergoing orthopedic hand surgery, manifesting as profound hypotension and urticaria. The timing of onset was closely associated with sugammadex administration. The patient recovered after extensive therapy including fluid, epinephrine, other vasopressors, steroid, and antihistamine administration. By intradermal skin test which was done at four weeks after anaphylaxis, we confirmed positive reactions to both sugammadex and sugammadex-rocuronium complex. Conclusions This is a rare case of sugammadex-induced anaphylaxis that both sugammadex and sugammadex-rocuronium complex were confirmed as allergenic epitopes.