Low concentration of heparin used for permanent catheters canal locking is effective and diminishes the risk of bleeding

PURPOSE: There is an increasing number of patients being dialyzed with permanent catheters (PC). In the majority of cases, heparin is used to maintain PC patency. This practice causes clotting disturbances due to heparin leakage and may predispose the patient to bleeding episodes. It has not been well studied whether lowering heparin concentration for canal locking decreases short-term bleeding complications after PC placement. METHODS: This was a prospective single-center randomized open-label trial conducted in hemodialyzed patients undergoing PC insertion. Low concentration of heparin (LCH) 2,500 IU/ml versus high concentration of heparin (HCH) 5,000 IU/ml was randomly used for catheter lumens locking. The primary endpoint was the occurrence of bleeding within 24 h after catheter placement. The effects of clinical and laboratory data on bleeding events were analyzed as secondary endpoints. RESULTS: Seventy-five patients (37 in LCH) were enrolled in the study. Only in the HCH group we found a significant prolongation of activated partial thromboplastin time (APTT) 2 h after PC placement (p < 0.001). There was a higher number of bleeding episodes in the HCH group (n = 16; 42.1%) than in the LCH group (n = 7; 18.9%) (χ(2) = 4.74; p = 0.029). In univariate analysis, assignment to HCH, baseline APTT, use of low molecular weight heparin, and femoral localization were associated with bleeding events. In multivariate analysis, the use of HCH (odds ratio [OR] 3.64; 95% confidence interval [95% CI] 1.10–12.05) and baseline APTT (OR 1.12; 95% CI 1.002–1.250) predicted bleeding after PC insertion. CONCLUSION: LCH used for canals locking decreases bleeding events in the first 24 hours after permanent catheter placement, compared to HCH.