The effect of perioperative ketamine and esketamine administration on postoperative nausea and vomiting in patients undergoing general anesthesia: a systematic review and meta-analysis.

backgroundThe 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.

methodsWe 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.

resultsFifty-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).

conclusionsKetamine 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.