title: The effect of uremia on platelet contractile force, clot elastic modulus and bleeding time in hemodialysis patients.
abstract: BACKGROUND
  Uremic bleeding frequently occurs in dialysis patients. Although its mechanism is not well characterized, acquired platelet dysfunction has been implicated in its pathogenesis. Skin bleeding time has been used to characterize platelet dysfunction in this population. However, the bleeding time is prone to error. The goal of this study was to compare the bleeding time to the novel platelet function parameters platelet contractile force and clot elastic modulus as well as platelet aggregation studies in controls and patients receiving maintenance hemodialysis.
  
  
  METHODS
  Forty-five subjects completed this study (25 controls, 20 dialysis). All subjects had the Ivy skin bleeding time procedure performed, as well as the collection of whole blood samples for the determination of platelet contractile force, clot elastic modulus, % von Willebrand Factor antigen, and platelet aggregation studies. Pearson's correlation determined the relationships between skin bleeding time and platelet function and clot structure parameters and markers of renal dysfunction.
  
  
  RESULTS
  Bleeding time was significantly prolonged in the dialysis group relative to controls. The platelet function parameters were not significantly different between groups. There was a significant relationship between bleeding time and creatinine concentration, however, no relationship existed between bleeding time and platelet function parameters.
  
  
  CONCLUSIONS
  Skin bleeding time poorly correlates with measurements of platelet function. There were no significant differences noted in platelet function between the groups despite the prolongations in bleeding time in the dialysis group. These data may suggest that the bleeding time reflects perturbations in platelet adhesion or secretion, and not aggregation. Further study is needed to characterize platelet function in dialysis patients.
authors.affiliation: Department of Pharmacy, Virginia Commonwealth University, Richmond, VA 23298-0533, USA. dbrophy@vcu.edu
authors.forename: Donald F
authors.initials: DF
authors.lastname: Brophy
authors.forename: Erika J
authors.initials: EJ
authors.lastname: Martin
authors.forename: Sheryl L
authors.initials: SL
authors.lastname: Carr
authors.forename: Barry
authors.initials: B
authors.lastname: Kirschbaum
authors.forename: Marcus E
authors.initials: ME
authors.lastname: Carr
mesh_terms: D000328:Adult; D001760:Bleeding Time; D001780:Blood Coagulation Tests; D003018:Clot Retraction; D003404:Creatinine / Q000097:blood; D004548:Elasticity; D005260:Female; D006801:Humans; D008297:Male; D009994:Osmolar Concentration; D011446:Prospective Studies; D006435:Renal Dialysis; D014511:Uremia / Q000097:blood* / Q000628:therapy*
chemical_list: D003404:Creatinine