Chlorine dioxide sterilization of implanted right atrial catheters in rabbits.

The disinfection of right atrial catheters in situ using chlorine dioxide was investigated. Catheters were implanted into rabbits (Oryctolagus cuniculi) and colonized by inoculation of Staphylococcus aureus, Sa-80, into the lumen. All of the catheters were colonized and the difference in numbers of bacteria recovered from animals destined for the control and disinfection groups was not significant. Animals were assigned randomly to the control or disinfection group. Treatment consisted of filling the catheter lumen of the disinfection group with chlorine dioxide and of the control group with sterile physiological saline daily for 15 minutes. In addition, both groups received systemic antimicrobial therapy. Cultures of blood withdrawn from the catheters and by venipuncture were negative for five of the nine control group animals after treatment for 5 days. Four control group catheters failed, after from 3 to 21 treatments, without ever achieving negative cultures. All nine animals in the disinfection group had negative cultures after treatment for 5 days. Subsequently, one animal from each group reverted to positive cultures. All nine control group catheters failed during the study, compared to only three disinfection group catheters (p less than 0.01). At necropsy, culture of cardiac blood, thrombi and catheter tubing sections demonstrated colonization of six in the control group and only one in the disinfection group (p less than 0.05). Rabbits tolerated the chlorine dioxide disinfection well and no adverse signs were noted.