title: Effect of anticoagulation on blood membrane interactions during hemodialysis.
abstract: BACKGROUND
  Adequate anticoagulation is a precondition to prevent extracorporeal blood clotting and to improve biocompatibility during hemodialysis. In this study, we performed a morphologic analysis by using scanning electron microscopy to compare three modes of anticoagulation-conventional unfractionated heparin (UFH), low molecular weight heparin (LMWH; dalteparin sodium), or sodium citrate during hemodialysis-on membrane-associated coagulation activation.
  
  
  METHODS
  Fifteen patients on regular hemodialysis therapy were investigated. Five patients received UFH, five patients LMWH, and five patients sodium citrate as an anticoagulant during a standardized hemodialysis protocol using a single-use polysulfone capillary dialyzer. Membrane-associated clotting was evaluated using a scanning electron microscope. A dialyzer clotting score was used for quantitative description of coagulation activation on membrane segments.
  
  
  RESULTS
  Using UFH as an anticoagulant revealed the most pronounced cell adhesion and thrombus formation and the highest dialyzer clotting score (11.5 +/- 1.3 of a maximal 20 points). LMWH had a lower dialyzer clotting score than UFH (10.4 +/- 1.2 of 20 points). During the use of sodium citrate, a negligible thrombus formation and the lowest dialyzer clotting score (1.6 +/- 0.6 of 20 points, P < 0.05) were observed.
  
  
  CONCLUSIONS
  The results of this investigation indicate that using sodium citrate as an anticoagulant during hemodialysis induces a lower activation of coagulation than both conventional and fractionated heparin, which might contribute to an improvement of biocompatibility of hemodialysis extracorporeal circulation.
authors.affiliation: Department of Medical and Chemical Laboratory Diagnostics, University of Vienna, Austria. roland.hofbauer@akh-wien.ac.at
authors.forename: R
authors.initials: R
authors.lastname: Hofbauer
authors.forename: D
authors.initials: D
authors.lastname: Moser
authors.forename: M
authors.initials: M
authors.lastname: Frass
authors.forename: R
authors.initials: R
authors.lastname: Oberbauer
authors.forename: A D
authors.initials: AD
authors.lastname: Kaye
authors.forename: O
authors.initials: O
authors.lastname: Wagner
authors.forename: S
authors.initials: S
authors.lastname: Kapiotis
authors.forename: W
authors.initials: W
authors.lastname: Druml
mesh_terms: D000328:Adult; D000925:Anticoagulants / Q000008:administration & dosage*; D001777:Blood Coagulation / Q000187:drug effects; D002448:Cell Adhesion / Q000187:drug effects; D002951:Citrates / Q000008:administration & dosage*; D017985:Dalteparin / Q000008:administration & dosage*; D004912:Erythrocytes / Q000648:ultrastructure; D005260:Female; D006495:Heparin, Low-Molecular-Weight / Q000008:administration & dosage*; D006801:Humans; D007676:Kidney Failure, Chronic / Q000097:blood / Q000628:therapy*; D008297:Male; D008422:Materials Testing; D008567:Membranes, Artificial; D008855:Microscopy, Electron, Scanning; D008875:Middle Aged; D006435:Renal Dialysis; D000077559:Sodium Citrate; D013927:Thrombosis / Q000188:drug therapy / Q000517:prevention & control
chemical_list: D000925:Anticoagulants; D002951:Citrates; D006495:Heparin, Low-Molecular-Weight; D008567:Membranes, Artificial; D000077559:Sodium Citrate; D017985:Dalteparin