Prophylactic antiemetic effects of dexamethasone versus 5-HT3 receptor antagonists in ear surgery: a systematic review and meta-analysis

Background The optimal strategy for reducing the high incidence of postoperative nausea and vomiting (PONV) after otologic surgical procedures remains inconclusive. Aim of the review This study compared the prophylactic antiemetic effects of dexamethasone with 5-hydroxytryptamine 3 receptor antagonists (5-HT3-RAs) in ear surgery. Method PubMed, Embase, and Cochrane Library were searched up to October 31, 2020 for randomized controlled trials that used dexamethasone either singly or in combination with 5-HT3-RAs for PONV prophylaxis in adults undergoing ear surgery. Studies in languages other than English and those without a control group of 5-HT3-RAs were excluded. Random effects meta-analyses were performed, and risk of bias was assessed using the version 2 of the Cochrane risk-of-bias tool. Main outcome measures include incidences of early (< 6 h) and overall (0–48 h) PONV, the overall requirement for rescue antiemetics, and the occurrence of adverse events. Results Eight trials of 733 adults were included, and the overall risks of bias were generally low. Pooled risk ratios (RRs) of early and overall PONV of dexamethasone versus 5-HT3-RAs were 2.0 (95% CI 0.8–5.1, I² = 82%), and 1.3 (95% CI 0.6–2.6, I² = 86%). In studies comparing dexamethasone plus 5-HT3-RAs with 5-HT3-RAs alone, pooled RRs of early and overall PONV were 0.8 (95% CI 0.4–1.4, I² = 30%), and 0.5 (95% CI 0.3–0.6, I² = 0%), respectively. Pooled RRs of the overall need for rescue antiemetics comparing 5-HT3-RAs with dexamethasone alone and in combination with 5-HT3-RAs were 1.2 (95% CI 0.4–3.9, I² = 73%) and 0.4 (95% CI 0.1–1.4, I² = 61%), respectively. Common adverse events reported were headache and dizziness, and the incidences range from 0 to 10% without significant differences between the groups. Conclusion The prophylactic antiemetic effects of dexamethasone versus 5-HT3-RAs in ear surgery did not significantly differ in the early and overall postoperative phases. The combination of dexamethasone with 5-HT3-RAs showed superior overall PONV prophylactic effects to 5-HT3-RAs alone in ear surgery, but their differences in the need for rescue antiemetics remained non-significant.