A randomised crossover trial comparing a single-use polyvinyl chloride laryngeal mask airway with a single-use silicone laryngeal mask airway.

Summary We compared insertion rates of single-use polyvinyl chloride laryngeal mask airways(LMAs) vs single-use silicone LMAs in 72 anaesthetised patients. Both airways were produced by Flexicare Medical. Laryngeal mask airwayinsertion was successful on the first attempt in 68/72 (94%) polyvinyl chlorideLMAs vs 64/72 (89%) silicone LMAs (p = 0.39). Overall insertion rates were 72/72 (100%) for the polyvinyl chlorideLMAs and 71/72 (99%) for the silicone LMAs (p = 1.0). Mean (SD) insertion timeswere similar for polyvinyl chlorideand silicone LMAs: 24.3 (5.1)s vs 24.8 (7.8)s (p = 0.64). Laryngeal mask airwayposition, as assessed using a fibrescope, was not different (p = 0.077). The median (IQR [range]) leak pressure was 16 (12–20 [6–30]) cmH2O for the polyvinylLMA and 18 (13–22 [6–30]) cmH2O or the silicone LMA (p = 0.037). In conclusion, we did not find any important differences between polyvinyl chlorideand silicone laryngeal mask airways.