Preoperative administration of hydroxyethyl starch or hypertonic saline to horses with colic.
Authors: Hallowell Gayle D, Corley Kevin T T
Journal: Journal of veterinary internal medicine
Summary
# Editorial Summary Hypovolaemia is a critical concern in equine colic surgery, but optimal fluid resuscitation strategies remain debated. Hallowell and Corley compared two proposed alternatives to standard crystalloid fluids—hypertonic saline and pentastarch (hydroxyethyl starch)—in 30 horses presenting with clinical signs of dehydration (elevated packed cell volume, plasma solids, or blood lactate) undergoing colic surgery, randomising them to receive 4 mL/kg of either fluid before anaesthetic induction and measuring cardiac output, stroke volume and arterial pressure at 30-minute intervals throughout surgery. Pentastarch demonstrated superior haemodynamic support, with cardiac index remaining significantly higher than hypertonic saline for up to 150 minutes post-induction, and stroke volume advantage evident at 30 and 60 minutes; both groups showed declining mean arterial pressure at 90 minutes. Whilst this work provides direct clinical evidence that pentastarch maintains better global perfusion during the perioperative period, the practical implications for tissue-level perfusion and surgical outcomes require further investigation—practitioners should consider these findings alongside other factors including cost, availability, and individual patient response when selecting preoperative fluid therapy for compromised colic cases.
Read the full abstract on PubMed
Practical Takeaways
- •For colic surgery cases, pentastarch appears to maintain better cardiac output and stroke volume during anesthesia compared to hypertonic saline, potentially improving intraoperative perfusion
- •Monitor mean arterial pressure closely around 90 minutes of anesthesia, as both fluids show pressure decline at this timepoint
- •While pentastarch shows hemodynamic advantages, clinical outcome differences remain unclear—further research needed to confirm if improved cardiac output translates to better recovery or reduced complications
Key Findings
- •Cardiac index was significantly higher in the pentastarch group compared to hypertonic saline group from 30 to 150 minutes after anesthetic induction (P = 0.04)
- •Stroke volume index was higher in pentastarch group at 30 minutes (P = 0.025) and 60 minutes (P = 0.04) after induction
- •Mean arterial pressure decreased at 90 minutes compared to 30 and 60 minutes in both groups
- •Preoperative pentastarch (4 mL/kg) provided superior intraoperative hemodynamics compared to hypertonic saline despite similar study design