Comparison of Two Activated Glutaraldehyde Solutions: Cidex Solution and Sonacide

Abstract

Cidex Solution, recommended by its manufacturer for 14 days repeated use to dis-infect respiratory therapy equipment, and Sonacide, recommended by its manufacturer for 28 days repeated use, were evaluated to compare their concentrations of glutaraldehyde (active ingredient) during continued use, to determine the maximum effective concentration of active ingredient against Pseudomonas aeruginosa, and to determine effects on equipment. The active ingredient in Sonacide decreased 45 per cent by the 15th day of use and 65 per cent by the 30th day. The Cidex active ingredient decrease for its recommended use period of 14 days was similar to the Sonacide decrease at 14 days. Sonacide pH became alkaline by the 11th day, while Cidex pH remained stable. Both Cidex and Sonacide disinfected with no failures at 0.5 per cent glutaraldehyde. Sonacide had a few failures at 0.4 per cent concentration and steadily more failures as concentration fell, with complete failure to disinfect at 0.05 per cent glutaraldehyde. Cidex had few failures through the 0.05 per cent concentra-tion. All nickel-plated metal equipment parts became corroded and discolored following Sonacide exposure, while no similar changes were seen after Cidex use. Dilution of the disinfectant by water present on the washed equipment appears to cause loss of glutaraldehyde. The amount of dilution of active ingredients is pro-portional to the number of use cycles and probably to the amount of equipment cycled. Every respiratory therapy service should be aware of these effects.