Enteral Fluid Therapy in Horses: Effects of Maintenance Hypotonic Electrolyte Solutions Containing Maltodextrin, Sucrose, or Dextrose Administered in Continuous Flow

Enteral hydration in cows: Comparison between continuous flow and bolus administration

BACKGROUND

Enteral hydration in cattle is most commonly performed as a bolus (B) via the ororuminal route, although continuous flow (CF) administration via the nasoesophageal route represents a viable alternative. Currently, no study has compared the effectiveness of these two methods. This study aimed to compare the efficiency of enteral hydration using CF and B to correct water, electrolyte and acid-base imbalances in cows.

METHODS

Protocols for the induction of dehydration were applied twice to eight healthy cows, with an interval of 1 week. In a crossover design, two types of enteral hydration were performed using the same electrolyte solution and volume equal to 12% of bodyweight (BW): CF (10 mL/kg/h, between 0 and 12 hours) and B (6% BW, twice, at 0 and 6 hours). Clinical and blood variables were determined at -24, 0, 6, 12 and 24 hours and compared using repeated-measures ANOVA.

RESULTS

Induced moderate dehydration and hypochloremic metabolic alkalosis were corrected after 12 hours using the two hydration methods, with no differences observed between the methods.

LIMITATIONS

The study was conducted with induced rather than natural imbalances, so the findings should be interpreted cautiously.

CONCLUSION

Enteral CF hydration is as effective as B hydration in reversing dehydration and correcting electrolyte and acid-base imbalances.

Comparative Trial of Continuous Flow Enteral and Intravenous Fluid Therapy in Horses

Continuous flow enteral fluid therapy with isotonic and hypotonic enteral electrolyte solutions are as safe and effective as intravenous fluid therapy. The aim of this study was to carry out a comparative assessment between continuous flow enteral and intravenous (IV) fluid therapy in adult experimentally dehydrated horses. Six experimentally dehydrated adult mares were used in a study carried out in a 6 × 3 crossover design, which each animal received three different treatments (isotonic enteral fluid therapy—EsISO, hypotonic enteral fluid therapy—EsHYPO and intravenous fluid therapy with Lactate Ringer Solution—LR IV, all in continuous flow). Solutions were administered at a rate of 15 mL⁻¹.kg⁻¹.h⁻¹ for 8 h, after 36 h of water and food deprivation. Serum and urinary biochemical assessment; urinary volume, pH and specific gravity; and blood gas analysis were measured at −36, 0, 2, 4, 6, and 8 h. The dehydration period (DP) caused discrete hydroelectrolytic and acid base imbalances. The EsISO, EsHYPO and LR IV increased blood volume. Enteral solutions restored the imbalances yielded by the DP and all treatments increased urine volume. Also, the EsHYPO and LR IV showed no effects in acid base balance, while EsISO showed slightly acidifying effect. The present study certifies the efficacy and safety of isotonic and hypotonic continuous flow enteral fluid therapy in comparison to IV fluid therapy in dehydrated horses.

Effects of Hypotonic and Isotonic Enteral Electrolyte Solutions Administered in Continuous Flow in Weaned Foals

The effects of fluid therapy with maintenance enteral electrolytic solutions administered by nasogastric route in continuous flow have not previously been studied in weaned foals. This study primary goal was to compare the effects of two maintenance enteral electrolytic solutions administered by nasogastric route in continuous flow on the hydro electrolytic balance in weaned foals. This paper was a controlled trial in a cross-over design (6 × 2) performed in six foals with a mean age of 7.3 ± 1.4 months; each animal received two treatments, IsoES and HypoES, with an interval of 7 days between treatments. After 12 h of fasting, the animals were treated with enteral electrolyte solutions administered via nasogastric route in continuous flow in a volume of 15 mL/kg/h for 12 h. The evaluations were performed at T-12h (the beginning of the fasting), T0h (end of fasting and beginning of fluid therapy), T4h (4 h of fluid therapy), T8h (8 h of fluid therapy), T12h (end of fluid therapy), and T24h (12 h after the end of fluid therapy). Twelve hours of fasting resulted in a reduction (P < 0.05) in body weight, abdominal circumference, whereas serum sodium, SID and enophthalmos increased. Twelve hours of fluid therapy normalized these parameters and promoted increased urinary volume and decreased urinary density without causing electrolyte imbalances. Both enteral electrolytic solutions were effective in reestablishing clinical and laboratorial variables without causing electrolyte imbalances.