Concentrated Heparin Lock Is Associated with Major Bleeding Complications after Tunneled Hemodialysis Catheter Placement

Abstract

Vascular access complications, including thrombosis, are associated with significant patient morbidity and mortality. Currently, up to 60% of new patients and 30% of prevalent patients are using a catheter for dialysis. To prevent interdialytic catheter thrombosis, these devices are routinely locked with concentrated heparin solutions. Several recent studies have elucidated the potential for abnormal coagulation markers (aPTT) that may arise from this practice. This abnormal elevation in aPTT may be explained by significant early and late leakage from the catheter that occurs after performing a catheter lock. To date no study has evaluated the impact of this practice, or the elevation in aPTT that may result from it, on bleeding complication rates. We conducted a retrospective analysis comparing bleeding rates in subjects who received concentrated heparin catheter lock (5000 u/cc) [group 1, n = 52] to those who received citrate or dilute heparin catheter lock (1000 u/cc) [group 2, n = 91] immediately after tunneled hemodialysis catheter insertion. Baseline characteristics did not differ between the groups except for the preprocedure INR, which was higher in the postpolicy group compared with the prepolicy group (1.29 vs. 1.21, p = 0.04). Results from logistic regression analyses revealed that the likelihood of a composite bleeding event in group 1 was 11.9 times that of a composite bleeding event in group 2, p = 0.04. Concentrated heparin (5000 u/ml) is associated with increased major bleeding complications posttunneled catheter placement compared with low-dose heparin (1000 u/ml) or citrate catheter lock solution, p = 0.02. Given the findings of this study, a randomized controlled trial comparing the safety and efficacy of common anticoagulation lock solutions is warranted.

Cathasept Line Lock and Microbial Colonization of Tunneled Hemodialysis Catheters: A Multicenter Randomized Controlled Trial

“…This suggests that catheter dysfunction may have been due to extra-luminal formation of fibrin sheaths or non-occlusive clots, rather than luminal problems. Due to a significant leakage of the instilled lock solution over time, as evident from experimental work and the well documented systemic anticoagulation effect of heparin locks 27,[56][57][58] , it is possible that catheters locked with heparin are less likely to develop extra-luminal occlusion. This might explain the differences seen between catheters locked with Cathasept and heparin in this study, but confirmatory work would be required.…”

The care and keeping of vascular access for home hemodialysis patients

“…• Bleeding risks have been noted with higher heparin concentrations 42 (see "Heparin Locking of Central Venous Catheters" in the Supporting Information) • Locking with 30% ethanol/4% trisodium citrate has been demonstrated to prevent the formation of biofilms in catheters in vitro, 43 and weekly 70% ethanol locks have been successfully used for infection prophylaxis (in vivo) in a proof-of-concept study, …”

Catheter Management in Hemodialysis Patients

“…Locking with lower heparin concentrations (2500 or 1000 U/ml) prevents catheter thrombosis as efficiently as 5000 U/ml (30,31). Heparin loss ("leak phenomenon") through diffusion from the lumen within the first hour or after injecting the locking solution (slow versus fast) may accidentally administer up to half the anticoagulant systemically (27) and may explain reports of bleeding episodes after heparin lock (32,33). No catheter seems to be free of this problem.…”