BACTERIOLOGICAL EFFICACY OF A CLEANING PROTOCOL FOR THE RE-USE OF CARDIAC ELECTROPHYSIOLOGY CATHETERS
Grabsch E.A., Smolich J.J., Yates L., Johnson P.D.R., Wellington H., McNeil J.J., Harper R., Grayson M.L.
Infectious Diseases & Clinical Epidemiology Department and Centre for Heart & Chest Research, Monash Medical Centre (MMC); Departments of Medicine and Epidemiology & Preventative Medicine, Monash University; Department of Human Services, Victoria.
Re-use of cardiac electrophysiology catheters (EPSs) marked "single-use" is controversial, but widely practised. We assessed the effectiveness of cleaning and sterilisation techniques currently used at MMC for re-used diagnostic and ablation EPCs which were experimentally contaminated with bacteria, including potential nosocomial pathogens.
Methods: The distal 10 cm of 12 diagnostic and 12 ablation multiply re-used (n < 9 times) EPCs were soaked for 1 hour in samples of fresh human blood spiked with 108 CFU/ml of either methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus (VRE) or Bacillus subtilis ATCC 11774 spores, and then allowed to dry for 2 hours before routine cleaning and ethylene oxide sterilisation. Post-sterilisation, catheters were incubated at 350C in tryptone soya broth (with 0.5% tween 80) and gently shaken for 14 days. Any broth that was observed to have growth was subcultured to identify the organism. If no bacterial growth was observed at 14 days, broths were challenged with a low inoculum (10-100 CFU/ml) of test organism to confirm that bacterial growth was not inhibited by trace amounts of residual detergent or ethylene oxide. At completion of each experiment, catheters were again cleaned and re-sterilised ready for re-use in replicate experiments.
Results: No test pathogens were grown from any of the EPCs during the 14 days incubation. Also, no residual antimicrobial effect after ethylene oxide sterilisation was noted to influence these results.
Conclusions: Within the power of this study, these data suggest that the current MMC cleaning/sterilisation protocol employed between re-use of EPCs provides effective sterilisation of the 3 test bacteria, despite the large non-clinical inocula used.
