A Randomised, Single-blind, Controlled Trial of Silicone Disposable Laryngeal Masks during Anaesthesia in Spontaneously Breathing Adult Patients

We hypothesised that two new silicone disposable laryngeal mask airways, Meditech Systems Limited (MSL) and ProAct (PA), would perform similarly to the Classic Laryngeal Mask Airway (cLMA) in spontaneously breathing adult patients. One hundred and twenty consecutive adult patients were prospectively enrolled and randomly allocated to one of three groups (PA, MSL, cLMA). All patients received a standardised anaesthetic and insertion technique. The overall success rates were 97.5% for all three masks, with one failure of laryngeal mask airway insertion in each group. There was no statistical difference in airway sealing pressures between the PA laryngeal mask airway (17.9+/-5.9 cmH2O), MSL laryngeal mask airway (18.5+/-6.9 cmH2O,) and cLMA (17.6+/-5.6 cmH2O) (P=0.816). There was no statistical difference in insertion times, ease of insertion, cuff pressure and cuff volumes. The MSL and PA disposable laryngeal mask airways provided comparable airway sealing pressures to the reusable cLMA.