title: Does the heparin lock concentration affect hemodialysis catheter patency?
abstract: OBJECTIVE
  Concentrated heparin solutions are instilled into the catheter lumens after each hemodialysis session to prevent catheter thrombosis. The heparin lock concentration at many centers has been decreased recently to reduce the risk of systemic bleeding and contain costs. However, the effect of this change on catheter patency is unknown. We compared catheter patency between two heparin lock solutions: 1000 versus 5000 units/ml.
  
  
  METHODS
  With use of a prospective, computerized, vascular access database, 105 patients with newly placed tunneled hemodialysis catheters, including 58 patients receiving a 5000 units/ml heparin lock and 47 patients receiving a 1000 units/ml heparin lock, were retrospectively identified. The primary endpoint was cumulative catheter patency and the secondary endpoint was frequency of thrombolytic instillation.
  
  
  RESULTS
  Cumulative catheter survival was similar in the two groups, being 71% versus 73% at 120 days in the low- and high-concentration heparin lock groups (hazard ratio of catheter failure, 0.97; 95% confidence interval, 0.45 to 2.09; P = 0.95). The frequency of tissue plasminogen activator instillation was significantly greater in the low-concentration heparin group (hazard ratio, 2.18; 95% CI, 1.26 to 3.86; P = 0.005). No major bleeding complications were observed in either treatment group. The overall drug cost for maintaining catheter patency was 23% lower with the low-concentration heparin lock ($1418 versus $1917) to maintain catheter patency for 1000 days.
  
  
  CONCLUSIONS
  Low-concentration heparin lock solutions do not decrease cumulative dialysis catheter patency, but require a twofold increase in thrombolytic instillation to maintain long-term patency.
authors.affiliation: Division of Nephrology, University of Alabama at Birmingham, Birmingham, Alabama 35233, USA.
authors.forename: D Maya
authors.initials: DM
authors.lastname: Ivan
authors.forename: Tamorie
authors.initials: T
authors.lastname: Smith
authors.forename: Michael
authors.initials: M
authors.lastname: Allon
mesh_terms: D000328:Adult; D000368:Aged; D000407:Alabama; D000925:Anticoagulants / Q000008:administration & dosage* / Q000191:economics; D002408:Catheters, Indwelling / Q000009:adverse effects / Q000191:economics; D016009:Chi-Square Distribution; D017046:Cost Savings; D004305:Dose-Response Relationship, Drug; D016527:Drug Costs; D004867:Equipment Design; D005260:Female; D005343:Fibrinolytic Agents / Q000008:administration & dosage; D006493:Heparin / Q000008:administration & dosage* / Q000191:economics; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D006435:Renal Dialysis / Q000009:adverse effects / Q000191:economics / Q000295:instrumentation*; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013927:Thrombosis / Q000191:economics / Q000209:etiology / Q000517:prevention & control*; D013997:Time Factors; D010959:Tissue Plasminogen Activator / Q000008:administration & dosage
chemical_list: D000925:Anticoagulants; D005343:Fibrinolytic Agents; D006493:Heparin; D010959:Tissue Plasminogen Activator