Intravenous Fluid Therapy: Can We Do It Better?

Intravenous fluid therapy should be initiated to replace fluid deficits. It should be followed with an IV solution designed to meet maintenance needs.

1. Introduction

Currently, all commercially available 5-l fluid products are designed as replacement fluids with an ionic composition similar to extracellular fluid. In equine practice, we lack IV fluids in 5-l bags that are designed as maintenance fluids for ongoing fluid support of horses that are maintained on IV fluids for >1 - 2 days.

2. Materials and Methods

Clinical hydration status, body-mass (BM) loss, and water and electrolyte balance were compared in six horses. The horses were deprived of feed and water for 5 days and were supported, in a randomized crossover design, with three fluids (1.5 ml/kg/h) with varying ionic composition: Normosol-R (R) [a], Normosol-M (M) [b], and modified Normosol-M (M+) [c].

3. Results and Discussion

Horses experienced a 3 - 9% BM loss during the infusion period; however, examination revealed normalhydration status during all infusion periods. No significant differences in plasma-electrolyte concentrations and acid-base balance were observed. Both urine and fecal Na+ and chloride (Cl-) excretion were significantly greater with R than with M or M+. All horses experienced a negative K+ balance during infusion with all fluid products, but the K+ deficit was less with M or M+ than with R. Increased urine output was seen with all fluids, but urinary losses of calcium and magnesium were attenuated with M+ compared with R or M. All in all, both maintenance solutions M and M+ were superior to R for water and electrolyte balance.

This study was supported by the Grayson Jockey Club Research Foundation and Abbott Laboratories.

Footnotes

[a] Normosol-R, Abbott Laboratories, Abbott Park, IL 60064.

[b] Normosol-M, Abbott Laboratories, Abbott Park, IL 60064.

[c] Modified Normosol-M+, Abbott Laboratories, Abbott Park, IL 60064.