Gentamicin plus citrate makes effective CVC lock
MedWire News: Use of a gentamicin/citrate locking solution in hemodialysis patients with a tunneled central venous catheter (CVC) for vascular access prevents catheter-related bloodstream infection more effectively than heparin, without increasing catheter clotting, US researchers report.
"CVCs are used for vascular access in hemodialysis patients who have no alternative access or are awaiting placement or maturation of a permanent access," explain John Moran (DaVita Inc., Burlingame, California, USA) and colleagues in the American Journal of Kidney Diseases.
The most serious complication of CVC use is catheter-related bloodstream infection, but clotting can also be a problem, they add.
Previous studies have investigated the use of different combinations of sodium citrate, heparin, and gentamicin as interdialytic locks for CVCs with varying degrees of success.
In the present study, Moran and team evaluated the use of gentamicin 320 µg/mL in 4% sodium citrate compared with heparin 1000 U/mL as routine catheter locks to prevent catheter clotting and bacteremia. Heparin 1000 U/mL is normally used as the standard catheter lock, they note.
A total of 303 adult maintenance hemodialysis patients, from 16 free-standing dialysis facilities, who were using a tunneled cuffed CVC for vascular access were randomly assigned to receive either the gentamicin/citrate (n=155) or heparin (n=148) lock.
Both groups received triple-antibiotic ointment on the catheter exit site during dressing changes at each dialysis treatment. The total follow-up period was 32,933 catheter-days (1083 months) in the heparin group and 39,827 catheter-days (1309 months) in the gentamicin/citrate group.
The researchers report that patients in the gentamicin/citrate group had a significantly lower rate of catheter-related bloodstream infection than those in the heparin group, at 0.28 versus 0.91 episodes per 1000 catheter-days.
Furthermore, the time to the first episode of bacteremia was significantly delayed in the gentamicin group compared with the heparin group.
The rate of tissue plasminogen activator use - an indicator of catheter clotting - did not differ significantly between the groups, at 2.36 versus 3.42 events per 1000 catheter-days in the gentamicin/citrate and heparin groups, respectively.
Of note, the team did not detect emergence of gentamicin resistance in blood cultures that were monitored throughout the study.
The low frequency of bacteremia in the heparin group suggests that triple-antibiotic ointment on the exit site is itself a simple and effective intervention to prevent bacteremia, remark Moran and co-authors.
However, they conclude: "It is striking that a significant improvement in bacteremia rate was seen in the treatment group even though the rate in the control group was low."
By Laura Dean