Optimal dosage and dwell time of ethanol lock therapy on catheters infected with Candida species

Abstract

Anti-infective lock therapy is a treatment strategy in conjunction with systemic antifungal agents for the treatment of intravascular catheter infections caused by fungi. In this study, the optimal dosage and dwell time of ethanol lock solution (ELS) effective against catheters infected by Candida species were assessed. Biofilm forming isolates of Candida albicans, Candida parapsilosis and Candida tropicalis was used as the study isolates. Infected catheters were exposed to ELS at 20%, 30%, 40%, 60% and 80% strength for a variety dwell times (15 min, 30 min, 1 h, 2 h, 4 h, 8 h, 12 h and 24 h). Fungal eradication was evaluated by the quantitative culture techniques. ELS's with 40% and greater strength sterilized the catheters within 30 min. Lower strength of ELS's (20% and 30%) sterilized the catheters in 24 h and 2 h, respectively. According to the study, lock therapy with ≥40% ethanol for 30 min appear to be the optimal schedule in sterilizing Candida infected catheters. Ethanol lock therapy with such concentrations and dwell time may be a useful adjunct to systemic anti-fungal antibiotics in sterilizing (and cleaning) and eradicating fungal catheter related infections in the hope of preserving crucial central venous access.