title: Bedside monitoring of anticoagulation in chronic haemodialysis patients treated with tinzaparin.
abstract: BACKGROUND
  During haemodialysis, anticoagulants are required to prevent clotting in the extracorporeal circuit. Low-molecular weight heparins (LMWH) are frequently used because of the ease of a single injection at the start of dialysis. Disadvantages of LMWH include the lack of a reliable bedside assay for measuring their anticoagulant effect.
  
  
  METHODS
  We investigated a bedside test for LMWH activity. The relationship between anti-Xa (chromogenic assay) and Hemonox point-of-care assay was evaluated in 21 dialysis patients (12 men and 9 women) with a median age of 71 years, receiving tinzaparin at the start of a haemodiafiltration session.
  
  
  RESULTS
  At the start, before tinzaparin administration, median (interquartile ranges) of Hemonox values were 74 (67-82) s. Thirty minutes after tinzaparin administration, Hemonox values were increased to 496 (360-736) s, followed by a decrease to 149 (135-301) s after 120 min, 102 (97-144) s after 180 min and 92 (83-100) s after 240 min. Corresponding anti-Xa activities were 0 (0-0), 1.12 (0.9-1.29), 0.74 (0.57-0.96), 0.47 (0.31-0.7) and 0.31(0.16-0.49) IU/mL. Hemonox values showed an exponential relation to anti-Xa levels. Interchangeability of tests was shown by Bland-Altman plot.
  
  
  CONCLUSIONS
  Point-of-care Hemonox test is a valuable bedside method for monitoring anti-Xa activity in dialysis patients anticoagulated with tinzaparin.
authors.affiliation: Nephrology Section, Ghent University Hospital, Ghent, Belgium.
authors.forename: Ruben
authors.initials: R
authors.lastname: Pauwels
authors.forename: Katrien
authors.initials: K
authors.lastname: Devreese
authors.forename: Wim
authors.initials: W
authors.lastname: Van Biesen
authors.forename: Sunny
authors.initials: S
authors.lastname: Eloot
authors.forename: Griet
authors.initials: G
authors.lastname: Glorieux
authors.forename: Raymond
authors.initials: R
authors.lastname: Vanholder
authors.forename: Annemieke
authors.initials: A
authors.lastname: Dhondt
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000627:therapeutic use*; D001777:Blood Coagulation / Q000187:drug effects; D002908:Chronic Disease; D065427:Factor Xa Inhibitors; D005260:Female; D005343:Fibrinolytic Agents / Q000627:therapeutic use*; D006495:Heparin, Low-Molecular-Weight / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic; D019095:Point-of-Care Systems; D012372:ROC Curve; D006435:Renal Dialysis; D000078222:Tinzaparin; D014914:Whole Blood Coagulation Time / Q000295:instrumentation / Q000379:methods*
chemical_list: D000925:Anticoagulants; D065427:Factor Xa Inhibitors; D005343:Fibrinolytic Agents; D006495:Heparin, Low-Molecular-Weight; D000078222:Tinzaparin
keywords: Hemonox; anti-Xa activity; haemodialysis; low-molecular weight heparin; tinzaparin