Systemic, Renal, and Colonic Effects of Intravenous and Enteral Rehydration in Horses

Abstract

Background: Intravenous (IV) and intragastric (IG) administration of fluid therapy are commonly used in equine practice, but there are limited data on the systemic, renal, and enteric effects.Hypothesis: IV fluid administration will increase intestinal and fecal hydration in a rate-dependent manner after hypertonic dehydration, but will be associated with significant urinary water and electrolyte loss. Equivalent volumes of IG plain water will result in comparatively greater intestinal hydration with less renal loss.Animals: Six Thoroughbred geldings. Methods: Experimental study. 6 by 6 Latin square design investigating constant rate IV administration at 50, 100, and 150 mL/kg/d over 24 hours in horses dehydrated by water deprivation. Equivalent volumes of IG plain water were administered by 4 bolus doses over 24 hours.Results: Water deprivation resulted in a significant decrease in the percentage of fecal water, and increases in serum and urine osmolality. IV fluids administered at 100 and 150 mL/kg/d restored fecal hydration, but increasing the rate from 100 to 150 mL/kg/d did not confer any additional intestinal benefit, but did result in significantly greater urine production and sodium loss. Equivalent 24-hour volumes of plain water resulted in greater intestinal water and less urine output.Conclusions and Clinical Importance: IV polyionic isotonic fluids can be used to hydrate intestinal contents in situations where enteral fluids are impractical. IV fluids administered at three times maintenance are no more efficacious and might be associated with adverse physiological findings after withdrawal. Bolus dosing of IG water can be used to restore intestinal water with minimal adverse effects.

Enteral Electrolyte Solutions With Different Osmolarities: Clinical and Laboratory Assessment in Equines

“…Studies conducted by Lopes et al [14], Avanza [11], Silveira et al [8] and Lester et al [17], in horses, and Atoji [15], Ribeiro Filho et al [16] in ruminants, observed this same behavior. Table 3 shows that there was an increase in the frequency of intestinal movements in animals treated with SEDext and SEMalt at T6h and T12h, whereas that increase in animals of the SEProp group was only detected at T12h.…”

Prospective survey of veterinary practitioners’ primary assessment of equine colic: clinical features, diagnoses, and treatment of 120 cases of large colon impaction

“…Recent evidence has demonstrated the efficacy of oral fluids for rehydrating ingesta and resolving impactions [16,26]. NSAIDs and oral fluids were used most frequently; spasmolytics and sedatives were also used commonly, whilst laxatives, IV fluids, opioids and electrolytes were seldom used on the primary assessment.…”

AreIVfluids useful for the treatment of large colon impactions?

“…, ; Lester et al . ). In these studies each horse acted as its own control, treatment were standardised and order administered randomised, therefore the quality of evidence is higher.…”

“…; Lester et al . ) baseline levels of faecal hydration prior to interventions being performed are used to determine outcome. See Table .…”

“…Lester et al . () attempted to address this by withholding water for 24 h prior to comparing treatment effects, this resulted in an approximate 5–8% reduction in faecal water content. All 3 studies monitored change in faecal water content as their major outcome; however, the magnitude of change in faecal water content required to significantly contribute to the resolution of an impaction is unknown.…”