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

Abstract

PurposeThere 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.MethodsThis 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.ResultsSeventy-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%) (χ2 = 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.ConclusionLCH used for canals locking decreases bleeding events in the first 24 hours after permanent catheter placement, compared to HCH.

Effect of ultra‐low dose and standard heparin locks on early tunnelled dialysis catheter outcomes in low‐risk dialysis patients

“…Our study contradicts previous publications that showed heparin lock concentrations above 2500 U/mL predispose to early catheter bleeding . Furthermore, it shows that lowering heparin dose below the standard 1000 U/mL dose confers no additional benefit in the first 24–48 h after TDC insertion.…”

“…Furthermore, Hryszko et al . on evaluation of 75 ESRD patients found that a 2‐h post‐lock APTT to be the only significant and determining factor for acute bleeding . The ability of heparin to leak by as much as 30% (i.e.…”

“…The effect of heparin on immediate catheter function has not been rigorously explored by previous studies . What good is a heparin lock in reducing bleeding if it increases catheter thrombosis?…”

“…13 Furthermore, Hryszko et al on evaluation of 75 ESRD patients found that a 2-h post-lock APTT to be the only significant and determining factor for acute bleeding. 11 The ability of heparin to leak by as much as 30% (i.e. 15% during early and 15% during late leaks), independent of fill volume or catheter design, has been ascribed to fluid motion driven by buoyancy forces between the higher density blood and the lower density heparin/saline mixture.…”

“…Our bleeding rate may seem higher than that reported by another group of nephrologists (Beathard et al), but it is comparable if not better than results from at least two studies of identical design where 'bleeding' was more rigorously defined and coded. 10,11,17 Minor bleeding is more likely to be dismissed as an unavoidable consequence of TDC insertion out when not properly defined apriori or heavy reliance is placed on progress notes entries, giving rise to both type 1 and type 2 errors.…”