Reusable Proseal™ laryngeal mask airways (PLMAs) can act as a vector for the transmission of prion diseases such as variant Creutzfeldt-Jacob disease. This study tested the hypothesis that supplementary ultrasonic cleaning facilitates the removal of protein deposits on PLMAs after anesthesia.

After clinical use, 40 PLMAs were randomly allocated into two groups. In the first group, the PLMAs were washed by hand and were then subsequently placed in an autoclave at 134℃ for 40 min (Group 1, n = 20). In the second group, the PLMAs were washed by hand and ultrasonic cleaning using an enzymatic solution for 5 min, and were then subsequently placed in an autoclave (Group 2, n = 20). In both groups, protein deposits were detected on PLMAs by erythrosin staining. A staining score designated as none (0%), mild (0-20%), moderate (20-80%) and severe (80-100%), was assigned to each site (outer surface, inner surface and edges of the cuff, airway and drain tube, finger strap) according to the percentage of the stained surface area.

Despite the cleaning of the masks, residual protein was found on the outer surface, inner surface and edge of the cuff, airway and drain tube, and finger strap of the PLMAs in both groups. Similar scores were observed for each part of the cleaned PLMAs in both groups, except for the outer surface of the PLMAs in Group 2 (P < 0.05).

We conclude that the use of an ultrasonic cleaner with an enzymatic solution may be effective to cleanse the outer surface of the PLMAs, but there were no differences in the total scores for both groups.