Study objective: To determine the utility of the laryngeal mask airway (LMA) in an ambulatory surgery practice.
Design: Prospective, longitudinal device (survival) study.
Setting: University-based ambulatory surgery center.
Patients: 1,831 ASA physical status I, II, and III outpatients undergoing superficial ambulatory surgery procedures.
Interventions: Twenty LMA devices were entered into service over a 2-year period and the number of uses, as well as the structural integrity, were assessed at the end of this study period. The serial number on each LMA device was used to track the number of times it was autoclaved, as well as the date that the device failed any of the standardized pre-use tests or was lost.
Measurements and main results: During the 2-year survey, 6,430 general anesthetics were administered at the ambulatory surgery center, with 1,831 (28%) using an LMA device for airway management. At the end of the study period, nine devices were still in use, three had been withdrawn for structural analysis by the manufacturer (after > 100 uses), three failed the pre-use test (after 38-82 uses), and five devices were lost (after 21-162 uses). The structural examination revealed that the tubes were 50% weaker; however, the cuffs, pilot balloons, and values were functioning normally. The median (range) number of uses was 92 (21-195). Thus, the 20 LMA devices evaluated tolerated an average of 92 autoclave cycles each over the 2-year observation period.
Conclusions: To optimize the use of the LMA device in the ambulatory setting, it is necessary to increase awareness that it is a nondisposable piece of equipment and to adhere to the manufacturer's instructions for cleaning, sterilization, and insertion.