Continuous Passive Disinfection of Luer Access Valves to Prevent Contamination

Background: Catheter hub contamination is a potential cause of line-related sepsis. Hub decontamination usually relies on a 30 second or more scrub with a disinfecting product. Compliance with this technique can vary.

Objective: This study aims to evaluate the effectiveness of a luer access valve disinfection cap (DC) with 70% alcohol affixed to catheter hubs to prevent line contamination.

Methods: The study was conducted at three acute care facilities and is divided into P1 (baseline) during which the standard protocol of a 30-second scrub was used to disinfect hubs before accessing and P2, during which the DC was used on all peripherally inserted central catheters (PICC). Adult patients with PICC inserted during their index hospitalization plus five or more consecutive PICC line days were consented and enrolled. On days 5, 6, or 7 and twice weekly thereafter during hospitalization, 1.5 ml of blood was withdrawn from each catheter lumen not actively in use and placed into an Isolator 1.5 Microbial Tube (Wampole, Cranbury, New Jersey) during first morning rounds by an vascular access registered nurse. The aspirate was quantitatively cultured by placing 1 ml of blood aseptically onto a 150mm agar plate containing Mueller Hinton Agar with 5% Sheep Blood (Remel, Lenexa, Kansas) . Outcome measures included the presence/absence of bacterial growth in the aspirate and the density of said organisms. Two-tailed Fisher’s exact and Wilcoxson Mann-Whitney U tests were used for significance testing. A fourth hospital was not involved in the study, but implemented the DC immediately and housewide central-line associated bloodstream infection (CLABSI) rates using NHSN criteria are reported here. The study was IRB approved.

Results: To date, 294 aspirates have been obtained with 12.3% (25/203) contaminated during P1; 7.7% (7/91) were contaminated following the P2 intervention (p=0.08). The median number of colony forming units per milliliter was 4 for P1 and 2 for P2 (p=0.14). Coagulase negative Staphylococcus species was the predominate organism in both periods (57% vs 60% P1:P2 respectively). CLABSI rates at the fourth (intervention only) hospital declined from 1.35 per 1,000 line days (2/1,477) in the 5 months preceding implementation of the DC to 0.61 per 1,000 line days (1/1,646) following its introduction.

Conclusions: Continuous passive disinfection via luer access cap with 70% alcohol is trending toward a reduction in hub contamination compared to current practice. DC appears to inhibit but may not eliminate contamination. In order to reach statistical significance an additional 76 samples in P2 at the same or lower hub contamination rate; this will be accomplished in two months at the current enrollment rate. The clinical impact on preventing CLABSI will require additional study.