Association between intraoperative end tidal carbon dioxide levels and postoperative nausea and vomiting: a systematic review and meta-analysis

The analysis does not provide strong evidence that EtCO2 levels are a key factor in influencing PONV incidence, even when the available covariates or the factors examined. Further large-scale, well-designed studies are needed to clarify this relationship and explore potential interactions with other PONV risk factors.