title: The effect of hetastarch 670/0.75 administered in vivo as a constant rate infusion on platelet closure time in the dog.
abstract: OBJECTIVE
  To evaluate the effects of hetastarch 670/0.75 on canine platelet function and clinical bleeding following its administration as a constant rate infusion (CRI) at 1 mL/kg/h and 2 mL/kg/h for 24 hours.
  
  
  METHODS
  In vivo, prospective, open-label, crossover study.
  
  
  METHODS
  Research laboratory at a university veterinary facility.
  
  
  METHODS
  Eight healthy, adult male research dogs.
  
  
  METHODS
  Each dog received 1 mL/kg/h hetastarch for 24 hours then 2 mL/kg/h with a washout period of 10 weeks between each experiment. Platelet closure time (CT) was measured using a platelet function analyzer with collagen adenosine diphosphate (ADP) cartridges. CT measurements were performed at baseline and 6, 12, and 24 hours following initiation of hetastarch infusion.
  
  
  RESULTS
  At 1 mL/kg/h, mean CT was significantly increased at the 12- and 24-hour time point relative to the baseline value, although mean CT never rose to a value above the reference interval during the 24-hour infusion. At 2 mL/kg/h, median CT was also significantly increased at the 12- and 24-hour time point relative to the baseline value. Administration of 2 mL/kg/h did progressively prolong the median CT value though only exceeded the reference interval at the 24-hour time point. Despite the prolongation of median CT, there was no clinical evidence of spontaneous bleeding in any dog during the 24-hour infusion at either CRI rate.
  
  
  CONCLUSIONS
  Hetastarch 670/0.75 when used as a 24-hour CRI at 1 and 2 mL/kg/h prolongs CT in healthy dogs at 6, 12, and 24 hours. Median CT only exceeded the reference interval at 24 hours at 2 mL/kg/h.
authors.affiliation: Veterinary Medical Teaching Hospital.
authors.forename: Kim A
authors.initials: KA
authors.lastname: Helmbold
authors.forename: Matthew S
authors.initials: MS
authors.lastname: Mellema
authors.forename: Kate
authors.initials: K
authors.lastname: Hopper
authors.forename: Steven E
authors.initials: SE
authors.lastname: Epstein
mesh_terms: D000818:Animals; D001792:Blood Platelets / Q000187:drug effects*; D018592:Cross-Over Studies; D004285:Dogs / Q000097:blood*; D006895:Hydroxyethyl Starch Derivatives / Q000494:pharmacology*; D008297:Male; D010952:Plasma Substitutes / Q000494:pharmacology*
chemical_list: D006895:Hydroxyethyl Starch Derivatives; D010952:Plasma Substitutes
keywords: coagulation; colloid; fluid therapy; hydroxyethyl starch; platelet function