Effects of 10% hydroxyethyl starch (HES 200/0.5) solution in intraoperative fluid therapy management of horses undergoing elective surgical procedures.
Authors: Brünisholz H P, Schwarzwald C C, Bettschart-Wolfensberger R, Ringer S K
Journal: Veterinary journal (London, England : 1997)
Summary
# Editorial Summary Maintaining adequate colloid osmotic pressure (COP) during equine anaesthesia is crucial for cardiovascular stability, yet fluid management protocols remain debated amongst practitioners. This trial compared 12 horses receiving 6 mL/kg of 10% hydroxyethyl starch (HES 200/0.5) infused over one hour against 13 control horses given equivalent lactated Ringer's solution during isoflurane-medetomidine anaesthesia, with measurements of COP, blood biochemistry, and cardiopulmonary variables recorded at multiple timepoints through 24 hours post-surgery. Pentastarch successfully maintained COP in treated horses whilst the control group experienced the typical colloid osmotic pressure decline associated with crystalloid-only fluid therapy; notably, 23.1% of control horses required rescue colloid administration to sustain cardiovascular function, whereas none of the HES-treated animals needed additional support. Blood biochemistry, electrolytes, and cardiopulmonary parameters showed no clinically meaningful differences between groups, with haematocrit changes proving transient and limited to the immediate post-infusion period. For systemically healthy horses undergoing routine surgical procedures, this dose of pentastarch appears effective at preserving intraoperative haemodynamic stability and reducing rescue interventions, though the authors appropriately note that extrapolation to critically compromised patients requires further investigation and that intermediate and longer-term clinical advantages remain unclear.
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Practical Takeaways
- •HES 200/0.5 pentastarch at 6 mL/kg is an effective perioperative colloid for systemically healthy horses undergoing elective surgery, reducing need for rescue colloid therapy
- •Routine use may decrease perioperative cardiovascular instability, though effects are intermediate-term only and long-term benefits remain unclear
- •This approach is most applicable to healthy horses; efficacy and safety in critically ill or compromised horses requires further investigation before clinical adoption
Key Findings
- •Pentastarch 10% HES (200/0.5) at 6 mL/kg effectively maintained colloid osmotic pressure during anaesthesia, unlike lactated Ringer's solution alone
- •23.1% of control horses required rescue colloid therapy versus 0% of HES-treated horses to maintain cardiovascular function
- •Packed cell volume was transiently lower in HES-treated horses immediately post-infusion and for 30 minutes thereafter
- •No clinically relevant differences in cardiopulmonary variables or blood biochemistry between treatments, with normalisation of most parameters within 12 hours