N-acetylcysteine lock solution prevents catheter-associated bacteremia in rabbits

Indwelling vascular catheters are the most common cause of nosocomial bloodstream infections. One approach to infection prevention is the use of antimicrobial catheter lock solutions, although their widespread use is limited due to concern regarding the emergence of antimicrobial resistance. The primary purpose of this study was to determine the efficacy of N-acetylcysteine (NAC) lock solution in preventing peripheral bacteremia using an in vivo model of catheter-associated infection.

Twenty-four hours after inoculating a clinical isolate of Staphylococcus aureus into the lumen of tunneled external jugular catheters in rabbits, a catheter lock solution that contained NAC vs. heparinized saline alone was allowed to dwell for two consecutive periods of 72 hours. Surveillance peripheral and centrally collected blood cultures were obtained. Distal intravascular segments of the catheters were removed at day 7 and cultured using a sonication method.

At 7 days after catheter insertion, none of the NAC-treated rabbits (0/8) developed peripheral bacteremia with S. aureus whereas 4/7 controls did (p=0.026). The bacterial yield from catheter tip cultures was not statistically different between the two arms.

These promising data encourage further clinical evaluation of an NAC lock solution for prevention of catheter-associated bacteremia in patients.