title: Effects of 2 concentrations of sodium citrate on coagulation test results, von Willebrand factor concentration, and platelet function in dogs.
abstract: BACKGROUND
  Blood collection tubes containing 3.2% (0.109 M) sodium citrate, instead of 3.8% (0.129 M) sodium citrate, have recently become available in the United States. These tubes are visually indistinguishable from the traditional 3.8% sodium citrate tubes, except for wording on the label. Consequently, samples for hemostatic evaluation are frequently collected in tubes containing the lower concentration of sodium citrate.
  
  
  OBJECTIVE
  Results of hemostasis assays are different in samples collected in 3.2% versus 3.8% sodium citrate.
  
  
  METHODS
  Twenty healthy dogs.
  
  
  METHODS
  This study aimed at determining whether results of standard coagulation tests, von Willebrand factor concentration (vWF:Ag), and platelet function with the platelet function analyzer PFA-100a were affected by the different concentrations of sodium citrate. Blood samples were collected in tubes containing either 3.2% or 3.8% sodium citrate concentrations and processed routinely for coagulation assays (one-stage prothrombin time [OSPT], activated partial thromboplastin time [aPTT], fibrinogen concentration, and platelet count), vWF:Ag, and platelet function assays with a PFA-100.
  
  
  RESULTS
  There was no significant difference between samples collected in 3.2% versus those collected in 3.8% sodium citrate for OSPT, aPTT, fibrinogen concentration, platelet count, or vWF:Ag. The closure times with collagen/adenosine diphosphate were significantly shorter (66 +/- 8.1 versus 74.8 +/- 9.7 seconds; P < .0001) with the 3.2% than with 3.8% sodium citrate concentration, and the hematocrit was significantly higher (47.9 +/- 5.6 versus 46.0 +/- 4.7 seconds; P = .03) in samples collected in 3.2% than in those collected in 3.8% sodium citrate.
  
  
  CONCLUSIONS
  There is no clinically relevant effect of collection of blood into 3.2% or 3.8% sodium citrate.
authors.affiliation: Veterinary Teaching Hospital, The Ohio State University, Columbus OH, USA.
authors.forename: F
authors.initials: F
authors.lastname: Morales
authors.forename: C G
authors.initials: CG
authors.lastname: Couto
authors.forename: M C
authors.initials: MC
authors.lastname: Iazbik
mesh_terms: D000818:Animals; D001800:Blood Specimen Collection / Q000295:instrumentation / Q000379:methods / Q000662:veterinary*; D002021:Buffers; D002951:Citrates / Q000494:pharmacology*; D004285:Dogs / Q000097:blood*; D004305:Dose-Response Relationship, Drug; D005260:Female; D005340:Fibrinogen / Q000032:analysis; D008297:Male; D010314:Partial Thromboplastin Time / Q000662:veterinary; D010976:Platelet Count / Q000662:veterinary; D010979:Platelet Function Tests / Q000379:methods / Q000662:veterinary*; D011517:Prothrombin Time / Q000662:veterinary; D000077559:Sodium Citrate; D014841:von Willebrand Factor / Q000032:analysis*
chemical_list: D002021:Buffers; D002951:Citrates; D014841:von Willebrand Factor; D000077559:Sodium Citrate; D005340:Fibrinogen