Potassium permanganate reduces protein contamination of reusable laryngeal mask airways

We tested the hypothesis that supplementary cleaning with potassium permanganate 2 mg/L eliminates protein deposits from reusable laryngeal mask airways (LMAs). Sixty previously used classic LMAs were hand-washed, machine-washed, dried, autoclaved, and then randomly allocated into two groups for supplementary cleaning. In Group A, the cuff was immersed in potassium permanganate 2 mg/L at 20 degrees C for 20 min. In Group B (control), the cuff was immersed in sterile water at 20 degrees C for 20 min. After supplementary cleaning, the LMAs were immersed in a protein staining solution and rinsed, and a high-resolution digital image was taken of the dorsal surface. The severity of staining was scored by an observer blinded to the type of supplementary cleaning. The severity of protein contamination was reduced after supplementary cleaning in potassium permanganate (P < 0.00001). Protein contamination was detected on 20% of LMAs after supplementary cleaning in potassium permanganate, compared with all LMAs in the control group. We conclude that supplementary cleaning with potassium permanganate 2 mg/L does not eliminate protein deposits from all LMAs, but it does reduce the number of devices contaminated from 100% to 20%.