Abstract: We identified a total of 9188 citations and included 15 RCTs conducted on 2242 participants in this review. All trials used the LMA Classic in American Society of Anesthesiologists (ASA) physical status I or II for patients undergoing elective general anaesthesia. Children were enrolled in 11 trials and adults in five trials. None of the trials were of high methodological quality. Eight of the 15 studies had adequate generation of random sequence, whereas only one trial had adequate concealment of random sequence. Three trials had blinded the outcome assessor. Thus, the majority of the studies appeared to have a high risk of bias in the study design. Using the GRADE approach, we found low quality evidence that the risk of laryngospasm was similar with early removal of the LMA (3.3%) versus late removal (2.7%): risk ratio (RR) 1.23, 95% confidence interval (CI) 0.74 to 2.03; 11 trials, 1615 participants. The quality of evidence was very low that the risk of coughing was less after early removal (13.9%) than late removal (19.4%): RR 0.52, 95% CI 0.29 to 0.94; 11 trials, 1430 participants. The quality of evidence for the risk of desaturation was also very low; there was no difference between early removal (7.9%) and late removal (10.1%): RR 0.68, 95% CI 0.4 to 1.16; 13 trials, 2037 participants. We found low quality evidence that the risk of airway obstruction was higher with early removal (15.6%) compared to late removal of the LMA (4.6%): RR 2.69, 95% CI 1.32 to 5.5; eight trials, 1313 participants. This systematic review suggests that current best evidence comparing early versus late removal of the LMA in participants undergoing general anaesthesia does not demonstrate superiority of either intervention. However, the quality of evidence available is either low or very low. There is a paucity of well designed RCTs and a need for large scale RCTs to demonstrate whether early removal or late removal of the LMA is better after general anaesthesia.

Plain-language summary: The evidence is current to August 2014. We found 15 randomized controlled trials on 2242 participants addressing this question. All the trials were performed in individuals who were not seriously ill under elective general anaesthesia. A LMA Classic was used for all studies. Children were enrolled in 11 studies and adults in five studies. None of the trials were of high methodological quality. The risks of complications such as laryngospasm (tight closure of the windpipe preventing effective breathing), and lowering of oxygen content in the blood (desaturation), were similar with early removal and late removal of the LMA. Coughing was less frequent after early removal of the LMA, with a risk of 13.9% as compared to the risk of 19.4% after late removal of the LMA. However, airway obstruction was more likely after early removal, with a risk of 15.6%, as compared to a risk of 4.6% after late removal of the LMA. No data were available on length of stay in the recovery room or hospital, or patient satisfaction. Thus, overall, this systematic review suggests that with the current available evidence, early and late removal of the LMA are comparable in persons undergoing general anaesthesia, and neither is superior in terms of safety. The quality of the evidence that is available is either low or very low for all the outcomes described. This was mainly due to poorly conducted studies, the small number of people that they recruited, and to a lesser extent, some variation in the study results.