A Comparison of the Disposable Versus the Reusable Laryngeal Mask Airway in Paralyzed Adult Patients

Abstract

A disposable (polyvinyl chloride) laryngeal mask airway (LMA) with dimensions identical to, but physical properties different from (stiffer tube/thicker cuff), the reusable (silicone) LMA has recently become available.We performed a randomized, cross-over study of 60 paralyzed, anesthetized patients to test the hypothesis that the use of these devices was different in terms of ease of insertion, airway sealing pressure, fiberoptic position, and changes in intracuff pressure during N2 O anesthesia. We also tested the hypothesis that the airway sealing pressure of the LMA is suboptimal if the cuff is inflated to a high intracuff pressure. Both the devices were inserted into each patient in random order, and their performance was assessed at two intracuff pressures (60 and 180 cm H2 O) by a blind observer. Subsequently, intracuff pressures were measured during N2 O anesthesia for the second device. Ease of insertion was similar: there was no difference in first attempt success rates (97% vs 98%) and insertion times (15 vs 13 s) for the disposable and reusable LMA, respectively. There were no differences in airway sealing pressure or fiberoptic position. Airway sealing pressure was significantly higher at 60 cm H2 O intracuff pressure compared with the airway sealing pressure at 180 cm H2 O for both devices (P < 0.02). During N2 O anesthesia, the intracuff pressure remained stable for the disposable LMA but increased significantly for the reusable LMA. We conclude that the disposable and reusable LMAs perform similarly in paralyzed adult patients, but that the disposable LMA has more stable intracuff pressures during N2 O anesthesia. Inflation of the LMA to high intracuff pressures produces a suboptimal seal. Implications: This randomized, single-blind, within-patient study of 60 adult patients shows that the disposable (polyvinyl chloride) and reusable (silicone) laryngeal mask airways perform similarly, but that the disposable laryngeal mask airway has more stable intracuff pressures during N2 O anesthesia. Inflation of either device to high intracuff pressures produces a suboptimal seal. (Anesth Analg 1998;87:921-4)