title: Reduction in platelet activation by citrate anticoagulation does not prevent intradialytic hemodynamic instability.
abstract: BACKGROUND
  The etiology of intradialytic hemodynamic instability is multifactorial. Of the various factors involved, a rise in core temperature seems to be crucial. In this respect, the bioincompatibility of hemodialysis (HD) treatment might play an important role. The application of cool dialysate reduces the number of periods of intradialytic hypotension (IDH) considerably. In rats, roller pump perfusion caused hypotension by shear stress induced platelet aggregation and subsequent serotonin release. During clinical HD, citrate anticoagulation abolished platelet activation almost completely. Hence, citrate anticoagulation might reduce IDH, whereas the beneficial effect of cool dialysate might be partly explained by reduced platelet activation.
  
  
  METHODS
  In the present study, blood pressure, IDH episodes, platelet activation, platelet aggregation, and serotonin release were studied crossover in 10 patients during HD with dalteparin anticoagulation at normal and low dialysate temperatures and during HD with citrate.
  
  
  RESULTS
  Citrate strongly reduced platelet activation, but did not improve IDH. The blood pressure was best preserved during cool-temperature HD, despite manifest platelet activation. Platelet activation was not accompanied by a rise in the plasma serotonin concentration.
  
  
  CONCLUSIONS
  Three major conclusions can be drawn: (1) it is unlikely that platelet activation and subsequent serotonin release underlie IDH in the clinical situation; (2) the protective effects of cool dialysate on IDH appear to be independent of HD-induced platelet activation, and (3) extrapolating results from rat experiments to the human situation requires uppermost prudence.
authors.affiliation: Department of Nephrology, Medical Center Alkmaar, Alkmaar, The Netherlands. mareillegritters@hotmail.com
authors.forename: Mareille
authors.initials: M
authors.lastname: Gritters
authors.forename: Piet
authors.initials: P
authors.lastname: Borgdorff
authors.forename: Muriel P C
authors.initials: MP
authors.lastname: Grooteman
authors.forename: Marianne
authors.initials: M
authors.lastname: Schoorl
authors.forename: Margreet
authors.initials: M
authors.lastname: Schoorl
authors.forename: Piet C M
authors.initials: PC
authors.lastname: Bartels
authors.forename: Geert Jan
authors.initials: GJ
authors.lastname: Tangelder
authors.forename: Menso J
authors.initials: MJ
authors.lastname: Nubé
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000008:administration & dosage; D001794:Blood Pressure / Q000187:drug effects; D019343:Citric Acid / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D006973:Hypertension / Q000209:etiology / Q000517:prevention & control*; D008297:Male; D008875:Middle Aged; D015539:Platelet Activation / Q000187:drug effects*; D006435:Renal Dialysis / Q000009:adverse effects*; D051437:Renal Insufficiency / Q000150:complications / Q000188:drug therapy* / Q000534:rehabilitation*
chemical_list: D000925:Anticoagulants; D019343:Citric Acid