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Editor, We thank Dr Makkar and Singh for their interest in our article.1 In our study, we had estimated the end-tidal sevoflurane concentration that is necessary for the insertion of a Laryngeal Mask Supreme.2 We agree that a reduced step change in the end-tidal concentration of sevoflurane (inferior to 0.5% as used in our study) would have provided higher accuracy in the patients’ responses to Laryngeal Mask Airway Supreme insertion. This was acknowledged in the limitations section of the article. A modified ‘two stage up-and-down method’ could also have been used to increase precision, in which after three changes of the observed response with the first stage (concentration of sevoflurane, 0.5%), the initial test change would be reduced in a second stage (concentration of sevoflurane, 0.2%), performing a predetermined number of changes from negative–positive up-and-down.3 However, the majority of adult studies that have investigated the ET50 of sevoflurane for several airway manipulations, such as tracheal intubation,4 the insertion of the cuffed oropharyngeal airway,5 the Laryngeal Mask Classic,3,4 or the Laryngeal Mask Airway Proseal,6 have used a 0.5% step in end-tidal concentration of sevoflurane. The use of this methodology allows us to compare the ET50 sevoflurane values obtained in our study with those in previous similar studies.3,4 With this procedure, the results obtained by different authors are essentially in the same range: for instance, Kodaka et al.6 reported that the ET50 of sevoflurane for Laryngeal Mask Classic insertion was 2.36%, and in the study by Tanaka et al.,5 it was 2%. Our study focused on the Laryngeal Mask Airway Supreme, but unfortunately, there are no previous trials to compare our results. We hypothesised that the sevoflurane requirements would be lower than those required for the Laryngeal Mask Airway Proseal, but our values were slightly higher. We do not know whether this minor difference would have disappeared if we had used a reduced step in the end-tidal concentration of sevoflurane. To resolve this hypothesis, a comparative randomised controlled study of the sevoflurane requirements to insert the Laryngeal Mask Airway Supreme or the Laryngeal Mask Airway Proseal would be necessary. Acknowledgements relating to this article Assistance with the letter: none. Financial support or sponsorship: none. Conflicts of interest: none. Presentation: none.