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

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.