Skin disinfection methods: prospective evaluation and postimplementation results.

BACKGROUND

Optimal skin disinfection ensures blood safety. In this study, efficacies of the two-step skin disinfection methods used at Canadian Blood Services (CBS) and two one-step methods produced by different manufacturers were compared.

STUDY DESIGN AND METHODS

In each of the three phases of the study, two methods were compared by disinfection of the antecubital fossae of study subjects. The two-step methods were compared in Phase I: Method A (isopropyl alcohol scrub and iodine tincture ampule) and Method B (isopropyl alcohol and chlorhexidine scrub and isopropyl alcohol and chlorhexidine ampule). In Phases II and III, Method B was compared to two different one-step swab sticks containing isopropyl alcohol and chlorhexidine (Methods C and D). Contact plates were applied on each of the subjects before and after disinfection and incubated at 37 degrees C for 24 hours followed by colony counting.

RESULTS

In 99% of the subjects, colonies per plate were reduced from approximately 60 to less than 10 after disinfection using any method. Method B was superior to Method A (p < 0.05) but was not significantly different from Methods C and D. Method D was implemented for skin disinfection at CBS with no significant effects on blood product contamination. Skin reactions increased from approximately 0.02% to approximately 0.62% after implementation, which were subsequently reduced to approximately 0.04%.

CONCLUSION

In this study, isopropyl alcohol and chlorhexidine disinfectants were more efficacious than isopropyl alcohol and iodine. There was no difference in efficacy between one-step and two-step procedures or between methods of application. A one-step chlorhexidine and isopropyl alcohol kit has been successfully implemented at CBS.