How Much Does Pharmacologic Prophylaxis Reduce Postoperative Vomiting in Children? Calculation of Prophylaxis Effectiveness and Expected Incidence of Vomiting Under Treatment Using Bayesian Meta-Analysis

摘要

The new Guidelines for the Management of Postoperative Nausea and Vomiting have recommendations for treatment in children and should be implemented with a new risk scale. The guidelines, however, do not give precise expected size of treatment effect. The authors calculated the various effect sizes for each treatment recommended, expressed as a relative risk (RR), that can be then be used to compute the risk of postoperative vomiting (POV) for each of the risk categories. The efficacy of 6 single-drug therapies and 5 combination treatments were considered. The single drugs were ondansetron, tropisetron, granisetron, dolasetron, dexamethasone, and droper-idol. The combinations were ondansetron plus dexamethasone or droperidol, tropisetron plus dexamethasone, dolasetron plus dexamethasone, and granisetron plus dexamethasone. Most of the treatments were administered intravenously. The search looked for controlled trials including only children in the postoperative setting with 1 end point being POVor nausea. The comparator had to be a placebo for the single-drug treatments; for the combinations, the comparator was either a placebo or 1 of the combination drugs. Studies were assessed with a Bayesian analysis. A posterior probability was calculated after inclusion of the data from the successive studies to update a previous probability existing before the inclusion of that study. An RR with a 95% credibility interval allowed calculation of a most pessimistic and most optimistic incidence of POV