A rational approach to the control of postoperative nausea and vomiting: evidence from systematic reviews. Part II. Recommendations for prevention and treatment, and research agenda

The control of postoperative nausea and vomiting (PONV) remains a difficult task. The optimal strategy to prevent PONV or to treat established symptoms is far from being obvious. Systematic reviews suggest that prophylaxis does not work very well, that there is a finite risk of adverse drug reactions with most antiemetic interventions, and that treatment may be more cost-effective than prophylaxis (1). Also, some interventions do not seem to work at all, and others are qualitatively or quantitatively very poorly documented. The intention of this second part of a series of two papers on rational strategies to control PONV symptoms was twofold. First, to provide clinically applicable recommendations on optimal prevention and treatment of PONV, based on data which represent the highest level of evidence currently available on efficacy and harm of antiemetic interventions. For this purpose, data from systematic reviews of relevant and valid randomised controlled trials only were considered (1). This does not exclude the possibility that clinicians may modify or adapt these recommendations by using valid data from individual studies on antiemetics which have not yet been reviewed systematically, and by taking into account their personal clinical experience. The second aim was to define an agenda for future PONV research. Systematic reviews are powerful tools to identify what we do not know (i.e. lack of evidence), and what we know with such