Postoperative nausea and vomiting (PONV) are among the most unfavourable anaesthetic outcomes attributed to the administration of inhaled anaesthetics. Accordingly, inhaled anaesthetics are frequently substituted by propofol when patients are at risk of PONV. As, on some occasions, inhalational anaesthesia may be favourable, the relative impact of propofol anaesthesia needs to be established based on robust data.OBJECTIVE
To compare the effectiveness of a single-drug pharmacological prophylaxis with total intravenous anaesthesia (TIVA) for prevention of PONV.DESIGN
Systematic review of randomised controlled trials with meta-analyses.DATA SOURCES
All available studies until 29 April 2015 were retrieved from MEDLINE, CENTRAL and EMBASE.ELIGIBILITY CRITERIA
Randomised controlled trials on adult patients undergoing general anaesthesia with at least one group receiving propofol-based intravenous anaesthesia without further antiemetic prophylaxis, and one group receiving inhalational anaesthesia with single-drug antiemetic prophylaxis.RESULTS
Fourteen studies involving 2051 patients were included. Compared with TIVA, after inhalational anaesthesia and single-drug antiemetic prophylaxis, there was no difference in the overall risk of PONV [relative risk (RR) 1.06, 95% confidence interval (CI) 0.85; 1.32, GRADE rating moderate], nor was there any difference in the risk of postoperative vomiting (RR 1.17, 95% CI 0.78; 1.76), need for rescue medication (RR 1.16, 95% CI 0.68; 1.99) or early PONV (RR 1.06, 95% CI 0.88; 1.27). However, TIVA was associated with an increased risk of late PONV (RR 1.41, 95% CI 1.10; 1.79, P = 0.006). Six studies investigated other side-effects associated with anaesthesia and found no differences between the two groups. Finally, there was evidence of a publication bias that included smaller studies favouring TIVA.CONCLUSION
This meta-analysis confirms the results from indirect comparisons in individual studies: instead of substituting inhalational anaesthesia with propofol-based TIVA, a similar antiemetic effect can be achieved by adding single-drug pharmacological prophylaxis to the inhalational anaesthetic.STUDY REGISTRATION
This systematic review with meta-analysis was registered at PROSPERO (www.crd.york.ac.uk/PROSPERO), study number CRD42015019571.