Head elevation and laryngeal mask airway Supreme insertion: A randomised controlled trial.

BACKGROUND A laryngeal mask airway (LMA) is usually inserted by conventional 7 cm head elevation. However, little is known about the association of head elevation degree and LMA insertion. We hypothesized that 14 cm head elevation would increase the first attempt success rate of LMA Supreme insertion compared with conventional 7 cm head elevation in patients undergoing transurethral resection of bladder tumour. METHODS Patients were randomly allocated to the high group (n = 55, 14 cm head elevation) or the control group (n = 55, conventional 7 cm head elevation). The primary outcome was the first attempt success rate of LMA Supreme insertion. RESULTS The first attempt success rate was significantly higher in the high than in the control group (53 [96.4%] vs. 40 [72.7%], P = 0.001, relative risk = 1.30, 95% confidence interval [CI] = 1.12-1.57, absolute risk reduction = 23.7%). Fibreoptic bronchoscope grade 4 (i.e., optimal position of the LMA) was significantly higher in the high group (35 [64.8%] vs. 18 [36.7%], P = 0.004, relative risk = 1.76, 95% CI = 1.16-2.68, absolute risk reduction = 30.9%). CONCLUSIONS Head elevation of 14 cm height increased the first attempt success rate of LMA Supreme insertion and fibreoptic bronchoscopic grade in patients undergoing transurethral resection of bladder tumour. High head elevation can be an effective option for successful LMA Supreme insertion.