Presence of protein deposits on 'cleaned' re-usable anaesthetic equipment

Twenty previously used and supposedly clean, sterilised laryngeal mask airways, five bougies and five Magill forceps from the operating theatre, and 61 laryngoscope blades from different sites within a single hospital were randomly collected and stained with erythrosin B dye, which stains proteins if present on surfaces. All 20 laryngeal mask airways had been used before and were stained: four (20%) showed heavy staining, five (25%) moderate staining and 11 (55%) mild staining. Two unused laryngeal mask airways used as controls were without staining. Thirty-four of 44 (77%) laryngoscope blades taken from the operating theatres, six of seven (86%) from the overnight intensive recovery room and all 10 (100%) from the wards were stained. None of the other items was totally clean. These findings suggest that current cleaning methods do not remove all proteinaceous material.