title: Cardiovascular, colloid osmotic pressure, and hemostatic effects of 2 formulations of hydroxyethyl starch in healthy horses.
abstract: BACKGROUND
  Lower molecular weight and molar substitution formulations of hydroxyethyl starch (HES) solutions might maximize cardiovascular function and colloid osmotic pressure (COP) and minimize adverse effects on coagulation.
  
  
  OBJECTIVE
  To compare effects of 1 low and 1 high molecular weight and molar substitution HES solution on cardiovascular variables, COP, and hemostasis in normal horses.
  
  
  METHODS
  Eight healthy adult horses.
  
  
  METHODS
  Randomized, crossover designed study: 10 mL/kg bolus of 6% HES (600/0.75) (hetastarch) (HS), 6% HES (130/0.4) tetrastarch (TS), and 0.9% NaCl (NS). Variables recorded included central venous pressure (CVP), noninvasive arterial blood pressure, packed cell volume (PCV), COP, and automated platelet analysis (CT).
  
  
  RESULTS
  Central venous pressure was increased for 8 hours after all treatment (baseline = 8.4 ± 3.8; 8 hours = 10.3 ± 3.5 cm H2 O; P < .001). HS and TS produced an increase in systolic arterial pressure (HS = 109.1 ± 11.9; TS = 109.5 ± 10.9 mmHg) and mean arterial pressure (HS = 80.4 ± 13.0; TS = 82.3 ± 10.1 mmHg) compared to NS (SAP = 103.2 ± 13.2 [P = .023]; MAP = 74.2 ± 11.4 mmHg [P = .048]). PCV decreased transiently with HS (baseline = 37.1 ± 4.4%; 1.5 hours = 31.6 ± 3.9%) and TS (baseline = 38.4 ± 3.9%; 1.5 hours = 32.2 ± 3.3%), but not NS (P = .007). COP was greater with HS (1 hour; 24.0 ± 2.1 mmHg) and TS (8 hours; 25.9 ± 2.1 mmHg) than NS (1 hour = 20.8 ± 2.6; 8 hours = 22.9 ± 3.1 mmHg; P < .001). CT was greater at 8 (HS = 178.6 ± 36.9; TS = 121.9 ± 33.3; NS = 108.3 ± 23.6 seconds) and 24 hours (HS = 174.2 ± 41.7; TS = 100.8 ± 26.0; NS = 118.7 ± 38.7 seconds; P < .001) in horses receiving HS than TS or NS.
  
  
  CONCLUSIONS
  Both TS and HS resulted in more effective volume expansion and arterial pressure support than NS. TS produced a more sustained effect on COP with shorter duration of adverse effects on platelet function than HS.
authors.affiliation: Department of Large Animal Medicine, College of Veterinary Medicine, University of Georgia, Athens, GA.
authors.forename: K L
authors.initials: KL
authors.lastname: Epstein
authors.forename: A
authors.initials: A
authors.lastname: Bergren
authors.forename: S
authors.initials: S
authors.lastname: Giguère
authors.forename: B M
authors.initials: BM
authors.lastname: Brainard
mesh_terms: D000818:Animals; D001794:Blood Pressure / Q000502:physiology; D018592:Cross-Over Studies; D005260:Female; D006487:Hemostasis; D006736:Horses / Q000502:physiology*; D006895:Hydroxyethyl Starch Derivatives / Q000008:administration & dosage / Q000494:pharmacology*; D007262:Infusions, Intravenous / Q000662:veterinary; D008297:Male; D009997:Osmotic Pressure / Q000502:physiology; D010314:Partial Thromboplastin Time / Q000662:veterinary; D010952:Plasma Substitutes / Q000008:administration & dosage / Q000494:pharmacology*; D010974:Platelet Aggregation / Q000502:physiology; D011517:Prothrombin Time / Q000662:veterinary; D011897:Random Allocation
chemical_list: D006895:Hydroxyethyl Starch Derivatives; D010952:Plasma Substitutes
keywords: Colloid therapy; Fluid therapy; Pharmacodynamics; Platelet function