RESUMO
BACKGROUND: Clean intermittent catheterization is one of the management of the neurogenic bladder caused by such disease as spinal injury. The purpose of this study is to assess the amount of time in a microwave oven required to eliminate seven pathogens isolated from urine of the patients, and to evaluate the effect of repeated use of a microwave oven on the patency and pliability of silicon catheter. METHODS: Seven microorganisms isolated from urine of patients were used as inoculating pathogens. These included Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Enterococcus faecalis, Enterococcus faecium, Staphylococcus aureus, Candida albicans. The silicon catheter was divided into six pieces (4 cm) and sterilized by ethylene oxide gas, Each piece of catheter was incubated for 60 minutes in a suspension of microorganisms, and placed in a plastic container. The piece was microwaved for 0 (control catheters) to 15 minutes a dose of 1,000 watts. Two methods were used. First method was a water-free method that was microwaved after removing water from the catheter. Second method was a water-added method that was microwaved after adding 5 mL of sterile water around the catheter. Then, that was placed in 15 mL sterile phosphate buffer in a conical tube. The fluid was cultured. Using a new silicon catheter, the microwave procedure was repeated until the catheter was no longer patent or pliable. RESULTS: Using a water-free method, E, coli, C. albicans were eliminated at 5 minutes, P. aeruginosa was at 8 minutes, K. pneumoniae, E. faecalis was at 12 minutes, but S. aureus was remained until 15 minutes, Using a water-added method, all strains were eliminated at 8 minutes. The characteristics of the silicon catheter after repeated procedures were not changed in patency or pliability until 100 times. CONCLUSION: The disinfection of silicon catheters using a microwave oven after adding water around the catheter was able to sterilize the frequent pathogens including C. albicans within 8 minutes. It was clinically useful to sterilize repeatedly the catheter using microwave oven without distorting the characteristics of the silicon catheter.