EFFECT OF ANTISEPTICS, ULTRAVIOLET-LIGHT AND LAVAGE ON AIRBORNE BACTERIA IN A MODEL WOUND

We modelled a 'clean' surgical wound lightly contaminated with airborn e bacteria, using agar, ovine muscle and ovine adipose tissue. This wa s used to assess the effect on bacteria of ultraviolet C light (UVC) 1 200 muW/cm2, hydrogen peroxide 3%, povidone-iodine 1% and 10%, chlorhe xidine 0.05%, pulsed jet lavage with UVC and syringe and needle lavage with chlorhexidine 0.05%. All the agents were effective on agar, but mixing with blood or plasma neutralised hydrogen peroxide and povidone -iodine 1%. All the agents were less effective on tissue specimens tha n on agar, but were more effective on adipose tissue than on muscle. A ll the antiseptics except chlorhexidine were less effective when blood or plasma was added to muscle specimens before disinfection. UVC afte r pulsed jet lavage had an additive effect. Syringe and needle lavage with chlorhexidine 0.05% was the most effective method tested; it redu ced colony counts by 98.8% and warrants clinical investigation.