Effect of esketamine on postoperative delirium in general anesthesia patients undergoing elective surgery: a meta-analysis of randomized controlled trials

Postoperative delirium is a common neurological complication, especially in older patients undergoing surgery, which is closely related to the poor prognosis of patients. The objective was to investigate the effects of esketamine on postoperative delirium in patients with general anesthesia.

The databases of PubMed, Embase, Cochrane Library and the Chinese National Knowledge Infrastructure were searched for all available randomised controlled trials on the effects of esketamine induction on postoperative delirium in patients undergoing elective general anesthesia from inception until April 21, 2024. We used RevMan5.4 software for data analysis. Dichotomous data was analyzed by risk ratios(RR) with a 95% confidence interval(CI), and continuous data by mean differences(MD). We also evaluated the risk of literature bias using the Cochrane Bias Risk Assessment tool.

We included a total of 17 randomized controlled trials, including 1286 patients undergoing elective general anesthesia. In 17 studies, esketamine significantly reduced the incidence of postoperative delirium (RR: 0.43; 95%CI: 0.33 ~ 0.57; p < 0.001). Five studies examined the incidence of postoperative adverse events (nausea, vomiting, dizziness and resporatory depression) and showed no statistically significant difference between the esketamine group and the control group (normal saline or dexmedetomidine) (RR: 0.82; 95%CI: 0.65 ~ 1.03; p = 0.08). In addition, this study found that the esketamine group had a lower incidence of hypotension (RR: 0.24; 95%CI: 0.12 ~ 0.48; p < 0.001) and a lower score on the visual analogue scale 24 h after surgery (MD: -0.44; 95%CI: -0.54 ~ -0.33; p < 0.001).

According to our meta-analysis, the use of esketamine during anesthesia induction significantly reduced the incidence of postoperative delirium in patients undergoing elective general anesthesia without increasing the incidence of postoperative adverse reactions.