Anaesthesia
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Review Meta Analysis
A meta-analysis of prevention of postoperative nausea and vomiting: randomised controlled trials by Fujii et al. compared with other authors.
The population sampling in randomised controlled trials by Fujii et al. have been shown to exhibit unusual distributions. This systematic review analysed the effectiveness of prophylactic antiemetics in trials by Fujii et al. compared with other authors. Granisetron was more effective in trials by Fujii et al., relative risk ratios (RRR (95% CI)): nausea 0.53 (0.42-0.67), p=0.00021; vomiting 0.60 (0.50-0.73), p=0.00094. ⋯ In contrast, in studies by Fujii et al., postoperative nausea and vomiting was more likely if granisetron was administered alone: nausea 4.20 (1.94-9.08), p=2.6×10(-4) ; vomiting 4.50 (2.55-7.97), p=2.3×10(-7); nausea or vomiting 5.00 (2.84-8.81), p=2.5×10(-8). Similarly, droperidol was less effective in studies by Fujii et al. if administered alone: vomiting 2.76 (1.25-6.11), p=0.01; nausea or vomiting 2.96 (1.46-6.00), p=2.7×10(-3). The conclusion is that if, as recommended, data with unusual distributions are removed from meta-analysis and articles by Fujii et al. excluded, then the antiemetic effects of granisetron and ramosetron are greatly reduced; further, there is no evidence of synergism between antiemetics and indeed, some evidence of antagonism between antiemetic agents.