The Effect of Ketamine on Emergence Agitation in Children: A Systematic Review and Meta-analysis.

Ketamine is believed to reduce incidence of emergence agitation in children undergoing surgery or procedure. However, recent randomised controlled trials reported conflicting findings.To investigate the effect of ketamine on emergence agitation in children.Databases of MEDLINE, EMBASE and CENTRAL were systematically searched from their start date until February 2019. Randomised controlled trials comparing intravenous ketamine and placebo in children were sought. The primary outcome was incidence of emergence agitation. Secondary outcomes included postoperative pain score, duration of discharge time and the adverse effects associated with the use of ketamine, namely postoperative nausea and vomiting, desaturation and laryngospasm.Thirteen studies (1,125 patients) were included in the quantitative meta-analysis. The incidence of emergence agitation was 14.7% in the ketamine group and 33.3% in the placebo group. Children receiving ketamine had a lower incidence of emergence agitation, with an odd ratio being 0.23 (95% confidence interval: 0.11 to 0.46), certainty of evidence: low. In comparison to the placebo, ketamine group achieved a lower postoperative pain score (odd ratio -2.42, 95% confidence interval -4.23 to -0.62, certainty of evidence: very low) and lower paediatric anaesthesia emergence delirium scale at 5-minute after operation (odd ratio -3.99, 95% confidence interval -5.03 to -2.95; certainty of evidence: moderate). However, no evidence was observed in term of incidence of postoperative nausea and vomiting, desaturation and laryngospasm.In this meta-analysis of 13 randomised controlled trials, high degree of heterogeneity and low certainty of evidence limits the recommendations of ketamine for the prevention of emergence agitation in children undergoing surgery or imaging procedures. However, the use of ketamine is well-tolerated without any notable adverse effects across all the included trials.