We tested the hypothesis that protein cross-contamination occurs during batch cleaning and autoclaving of a reusable extraglottic airway device, the ProSeal TM laryngeal mask airway. At the end of each day for 10 days, nine laryngeal mask airways that had been used for non-intra-oral surgery were cleaned and autoclaved alongside a new unused laryngeal mask airway. In addition, a new unused laryngeal mask airway underwent the same cleaning and autoclaving procedures in isolation. Protein staining was more frequently detected on the unused laryngeal mask airways that were processed by batch rather than in isolation (p < 0.01). Protein staining was detected on all unused laryngeal mask airways that were processed by batch, but none on those processed in isolation. Protein staining was more severe with the used compared with the unused laryngeal mask airways (p < 0.001). We conclude that protein cross-contamination of the laryngeal mask airway occurs during batch cleaning and autoclaving and recommend that reusable airway devices are cleaned in isolation.

Summary In this three‐stage study, we test the hypothesis that supplementary cleaning with potassium permanganate ≥4 mg.l−1 eliminates protein and particle contamination from the reusable Classic™ laryngeal mask airway. The first stage involved supplementary cleaning of 70 1 × 1 cm segments from deliberately contaminated laryngeal mask airways using potassium permanganate at 0, 2, 4, 8, 16, 32 and 64 mg.l−1 and testing for protein staining. This showed that the lowest concentration required to eliminate protein contamination was 8 mg.l−1. The second stage involved supplementary cleaning of 50 used laryngeal mask airways with either potassium permanganate 8 mg.l−1 or saline and testing for protein staining. This showed that protein contamination was lower in the potassium permanganate group (p < 0.00001): all laryngeal mask airways in the control group and none in the potassium permanganate group were contaminated. The third stage involved scanning electron microscopic examination of 1 × 1 cm segments from three laryngeal mask airways used in the control group, three from the potassium permanganate group, plus three brand new laryngeal mask airways. The mean density of ≥1 μm surface particles was lower in the potassium permanganate 8 mg.l−1 than the control group (21 vs. 121 .cm−2, p < 0.0001) and was similar to brand new laryngeal mask airways (24 .cm−2). We conclude that supplementary cleaning with potassium permanganate 8 mg.l−1 eliminates protein deposits from reusable laryngeal mask airways and reduces particle contamination to similar levels to brand new laryngeal mask airways.