Antibiotic Lock Technique for Prevention of Cuffed Tunnel Catheter Associated Bacteremia

Abstract

Central venous cuffed tunnel catheters are commonly used for short term or long term hemodialysis access. However, catheter-associated bacteremia is a common complication. It has been suggested that the addition of antibiotics to the catheter during the interdialytic interval results in a decrease in bacterial colonization and thereby a decrease in catheter associated infections. To test this hypothesis, a prospective, randomized study was performed comparing a gentamicin citrate mixture to standard heparin as the catheter lock. The effect of covering the catheter hub in a sterile bag on the infection rate was additionally tested. From January 1999 to April 2000, all patients who underwent tunnel catheter placement or change (55 catheters) in the Nephrology Interventional Laboratory at Louisiana State University Health Sciences Center in Shreveport, were prospectively randomized as follows: group 1 (n=14): Antibiotic lock with tricitrasol (46.7%), gentamicin (40 mg/ml) and saline in a ratio of 1:5:5 and catheter hub covered with a sterile plastic bag after cleaning with a 10% povidone iodine solution; group 2 (n=22): Heparin lock and sterile plastic bag over catheter hub after cleaning with povidone iodine; and group 3 (n=19): Heparin lock alone. The primary end points of the study were catheter-associated bacteremia and thrombosis. Catheter loss due to access maturation, transplant or transfer were censored. There were a total of 4,805 at risk patient-days. The total number of catheter associated bacteremias were one in group 1, four in group 2 and four in group 3. The number of catheter associated bacteremias per 1000 patient-days in each group was 0.62, 3.05, and 2.11 respectively. The sixty day percent survival of catheters in each group was 74 +/- 12, 55 +/- 12 and 59 +/- 11 respectively. 1) Tricitrasol and gentamicin as an antibiotic lock reduced the incidence of catheter associated bacteremia; 2) Covering the catheter hub with a sterile bag did not provide an additional advantage; 3) The antibiotic lock improved overall survival of catheters.