Cardiovascular, colloid osmotic pressure, and hemostatic effects of 2 formulations of hydroxyethyl starch in healthy horses.

摘要

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. Hypothesis/Objectives: 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. Animals: 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+or-3.8; 8 hours=10.3+or-3.5 cm H₂O; P<.001). HS and TS produced an increase in systolic arterial pressure (HS=109.1+or-11.9; TS=109.5+or-10.9 mmHg) and mean arterial pressure (HS=80.4+or-13.0; TS=82.3+or-10.1 mmHg) compared to NS (SAP=103.2+or-13.2 [P=.023]; MAP=74.2+or-11.4 mmHg [P=.048]). PCV decreased transiently with HS (baseline=37.1+or-4.4%; 1.5 hours=31.6+or-3.9%) and TS (baseline=38.4+or-3.9%; 1.5 hours=32.2+or-3.3%), but not NS (P=.007). COP was greater with HS (1 hour; 24.0+or-2.1 mmHg) and TS (8 hours; 25.9+or-2.1 mmHg) than NS (1 hour=20.8+or-2.6; 8 hours=22.9+or-3.1 mmHg; P<.001). CT was greater at 8 (HS=178.6+or-36.9; TS=121.9+or-33.3; NS=108.3+or-23.6 seconds) and 24 hours (HS=174.2+or-41.7; TS=100.8+or-26.0; NS=118.7+or-38.7 seconds; P<.001) in horses receiving HS than TS or NS. Conclusion and Clinical Importance: 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.