Appraising and highlighting gaps among prophylactic intervention studies for reducing the incidence of postoperative nausea and vomiting in children: a systematic review

Objectives: Postoperative nausea and vomiting (PONV) is a leading perioperative morbidity outcome following general anaesthesia. This systematic review aims to identify, appraise and summarise the evidence synthesis studies of prophylactic interventions that reduce the incidence of paediatric PONV, thereby highlighting knowledge gaps and avenues of future research.

Design: Systematic review using the AMSTAR-2 (A MeaSurement Tool to Assess Systematic Reviews 2) tool and the ROBIS (Risk Of Bias In Systematic reviews) tool.

Data sources: Seven major databases, including MEDLINE and EMBASE, from inception to 23 September 2022.

Eligibility criteria for selecting studies: Evidence synthesis studies of only randomised controlled trials that explored prophylactic interventions for PONV in children undergoing general anaesthesia.

Data extraction and synthesis: Following screening process by two reviewers, data were extracted from all eligible studies, including demographic parameters and details of interventions. Eligible studies were categorised into 'pharmacological' and 'non-pharmacological' groups and high-risk surgical groups of 'strabismus' and 'tonsillectomy' for qualitative synthesis.

Results: There were 20 evidence synthesis reviews (17 meta-analyses, 2 systematic reviews, 1 network meta-analysis): 14 investigated pharmacological PONV prophylaxis in children, 5 investigated non-pharmacological interventions, 1 studied both pharmacological and non-pharmacological interventions. Monotherapy pharmacological prophylaxis agents, for example, dexamethasone (relative risk (RR) 0.49, 95% CI 0.41 to 0.58), 5-hydroxytryptamine (5-HT₃) antagonists (OR 0.12, 95% CI 0.07 to 0.20) and α₂-adrenoreceptor agonists (dexmedetomidine: RR 0.33, 95% CI 0.21 to 0.54), are more effective than placebo. A combination of pharmacological agents provided superior efficacy to monotherapy, particularly dexamethasone and 5-HT₃ antagonists (RR 0.21, 95% credible interval 0.15 to 0.28). Acustimulation practice was consistently favourable in preventing PONV compared with placebo (RR 0.36, 95% CI 0.25 to 0.52).

Conclusion: Monotherapy pharmacological prophylaxis is more effective than placebo in reducing the incidence of paediatric PONV, with the efficacy increased further by using combination pharmacotherapy. Further research must compare multiple treatment arms of pharmacological and non-pharmacological prophylaxes for PONV to identify the optimal multimodal prophylaxis regimen.

Prospero registration number: CRD42021236698.