Effect of a 24-hour infusion of an isotonic electrolyte replacement fluid on the renal clearance of electrolytes in healthy neonatal foals.

The study evaluates the impact of a 24-hour infusion of isotonic electrolyte replacement fluid (IERF) on certain physiological parameters in healthy newborn foals. Findings suggest that using IERF with a normal sodium concentration may not be suitable for neonatal foals needing maintenance fluid therapy.

Study Objectives and Methodology

• This study aimed to examine the effects of a 24-hour IERF infusion concerning weight, serum and urine electrolyte levels, and other clinical variables in healthy neonatal foals.
• The research design was a prospective study, which included 4 healthy 4-day-old foals as subjects.
• Each foal was administered an IERF at an estimated rate of 80 mL/kg/day for 24 hours.
• Body weight was measured before and after the infusion, while urine was collected via catheter during 4-hour periods and blood samples were collected every 4 hours.
• Several critical variables were recorded at regular intervals during the infusion, including urine production; urine and serum osmolalities; sodium, potassium, and chloride concentrations in urine and serum; urine and serum creatinine concentrations; urine osmolality-to-serum osmolality ratio (OsmR); transtubular potassium gradient (TTKG); and the percentage of creatinine clearance (Cr(cl)) of electrolytes.
• Net fluid and whole-body electrolyte changes from baseline values were calculated immediately after the study period.

Results

• The findings showed that relative to baseline values, urine and serum sodium and chloride concentrations, urine and serum osmolalities, OsmR, and percentage Cr(cl) of sodium and chloride significantly increased at different time points during the infusion.
• However, urine production did not change significantly with the IERF infusion.
• After 24 hours, weight, TTKG, serum creatinine concentration, and whole-body potassium had dropped significantly from baseline levels.

Conclusions

• The results of this study suggest that an IERF with a physiological concentration of sodium may not be appropriate for use in neonatal foals that need maintenance fluid therapy.
• While the infusion resulted in significant changes in several critical variables, some variables like urine production did not show any significant change, indicating a potential lack of fluid balance.