Sepsis of vascular catheters. II: In vitro disinfection of colonized tubing.

Preparatory to development of in situ disinfection of implanted catheters, silicone rubber tubing colonized by incubation with Staphylococcus aureus, Staphylococcus epidermidis, or Klebsiella pneumoniae was used to test the efficacy of various chemicals in vitro. Protocols sterilizing all segments colonized for 24 h (n = 30) were immersion into 50% povidone iodine for 5 and 60 min, 100% povidone iodine for 5, 15, and 60 min, 1.2 x 10(3) ppm chlorine dioxide for 15 and 60 min, and 1.2 x 10(3) ppm chlorine dioxide buffered to pH 5.1 for 60 min. Immersion in up to 2% chlorhexidine, 7.4% formaldehyde, or 6% sodium hypochlorite for up to 60 min failed to sterilize all segments. None of 117 control segments were sterilized. Segments colonized for seven days were sterilized by immersion into 100% povidone iodine for 15 or 60 min. Use of 1.2 x 10(3) ppm chlorine dioxide for 60 min sterilized 97% of segments tested. Lower concentrations and shorter exposure times failed to sterilize all segments. Eighteen silicone rubber catheters, colonized on the outer surface, were all sterilized within 24 h by a chlorine dioxide solution placed in the lumen and diffusing through the wall to kill the bacteria.