Background: The effectiveness of various solutions instilled into the central venous catheter lumens after each hemodialysis session (catheter locking solutions) to decrease the risk of catheter malfunction and bacteremia in patients undergoing hemodialysis is unknown.
Methods: We randomly assigned 225 patients undergoing long-term hemodialysis in whom a central venous catheter had been newly inserted to a catheter-locking regimen of heparin (5000 U per milliliter) three times per week or recombinant tissue plasminogen activator (rt-PA) (1 mg in each lumen) substituted for heparin at the midweek session (with heparin used in the other two sessions). The primary outcome was catheter malfunction, and the secondary outcome was catheter-related bacteremia. The treatment period was 6 months; treatment assignments were concealed from the patients, investigators, and trial personnel.
Results: A catheter malfunction occurred in 40 of the 115 patients assigned to heparin only (34.8%) and 22 of the 110 patients assigned to rt-PA (20.0%)--an increase in the risk of catheter malfunction by a factor of almost 2 among patients treated with heparin only as compared with those treated with rt-PA once weekly (hazard ratio, 1.91; 95% confidence interval [CI], 1.13 to 3.22; P = 0.02). Catheter-related bacteremia occurred in 15 patients (13.0%) assigned to heparin only, as compared with 5 (4.5%) assigned to rt-PA (corresponding to 1.37 and 0.40 episodes per 1000 patient-days in the heparin and rt-PA groups, respectively; P = 0.02). The risk of bacteremia from any cause was higher in the heparin group than in the rt-PA group by a factor of 3 (hazard ratio, 3.30; 95% CI, 1.18 to 9.22; P = 0.02). The risk of adverse events, including bleeding, was similar in the two groups.
Conclusions: The use of rt-PA instead of heparin once weekly, as compared with the use of heparin three times a week, as a locking solution for central venous catheters significantly reduced the incidence of catheter malfunction and bacteremia. (Current Controlled Trials number, ISRCTN35253449.).