Abstract: We included 15 RCTs with 1833 participants. We determined that none of the RCTs were of high methodological quality. For our primary outcomes, pooled results from two trials suggest that time to emergence from anaesthesia, that is, time needed to follow verbal commands, was longer with isoflurane than with propofol (mean difference (MD) -3.29 minutes, 95% confidence interval (CI) -5.41 to -1.18, low-quality evidence), and time to emergence from anaesthesia was not different with sevoflurane compared with propofol (MD 0.28 minutes slower with sevoflurane, 95% CI -0.56 to 1.12, four studies, low-quality evidence). Pooled analyses for adverse events suggest lower risk of nausea and vomiting with propofol than with sevoflurane (risk ratio (RR) 0.68, 95% CI 0.51 to 0.91, low-quality evidence) or isoflurane (RR 0.45, 95% CI 0.26 to 0.78) and greater risk of haemodynamic changes with propofol than with sevoflurane (RR 1.85, 95% CI 1.07 to 3.17), but no differences in the risk of shivering or pain. Pooled analyses for brain relaxation suggest lower risk of tense brain with propofol than with isoflurane (RR 0.88, 95% CI 0.67 to 1.17, low-quality evidence), but no difference when propofol is compared with sevoflurane. The finding of our review is that the intravenous technique is comparable with the inhalational technique of using sevoflurane to provide early emergence from anaesthesia. Adverse events with both techniques are also comparable. However, we derived evidence of low quality from a limited number of studies. Use of isoflurane delays emergence from anaesthesia. These results should be interpreted with caution. Randomized controlled trials based on uniform and standard methods are needed. Researchers should follow proper methods of randomization and blinding, and trials should be adequately powered.

Plain-language summary: The evidence is current to June 2014. We included studies with participants from all age groups except neonates (infants less than 28 days old) who received injectable or gas techniques of anaesthesia during surgery for brain tumour. We reran the searches for all databases in March 2016 and found two studies that are awaiting classification. We will deal with them when we update this review. We found 15 eligible studies with 1833 participants. These studies compared one injectable drug (propofol) with two gaseous drugs (sevoflurane and isoflurane). Although isoflurane was associated with slower awakening (about three and a half minutes) compared with propofol, researchers found no important differences between propofol and sevoflurane. In terms of adverse effects, propofol was less likely to cause nausea and vomiting than either gas anaesthetic (about half as likely) but was more likely to be associated with changes in blood pressure. Overall, we found that isoflurane is associated with slower awakening, but we have found no evidence of important differences between sevoflurane and propofol. We found evidence of low quality for our main outcome of quick wakefulness, and the effect of injectable anaesthetic technique in people undergoing brain tumour surgery is uncertain. Further research and well-designed studies are needed.