Hypertonic and isotonic saline solutions in dehydration therapy in neonate calves: comparison of clinical profile and serum and urinary concentrations of electrolytes

Abstract

Sixteen male Holstein calves, from 1 to 9 days old, were used in the study. The purpose was to compare the effect of both hypertonic (NaCl at 7.2%, 2,400 mOsm/l) and isotonic (NaCl at 0.9%, 300 mOsm/l) saline solutions associated with oral rehydrating solution, using the serum biochemical profile, serum and urinary osmolality, and electrolytic renal clearance and excretion in neonate calves with osmotic diarrhea-induced dehydration. Calves were randomly distributed into four groups: group 1, normal; group 2, treatment with hypertonic saline plus oral solution; group 3, treatment with isotonic saline plus oral solution; and group 4, with no treatment (diarrhea control group). Animals with no treatment presented aqueous diarrhea, severe hyponatremia, hypochloremia, hypokalemia, decrease of rhythm of glomerular filtration, hyperphosphatemia, and azotemia. The use of small volumes of hypertonic saline solution in a single dose restored the plasma volume, serum sodium and chloride concentrations, and rhythm of glomerular filtration. When compared to isotonic saline, hypertonic saline brought about a less marked hemodilution and reestablished serum potassium concentration and rhythm of glomerular filtration. The use of large volumes of isotonic saline solution is associated with a higher rhythm of glomerular filtration, larger hemodilution, and urinary losses of sodium and chloride. We conclude that a rapid infusion of small volumes of hypertonic saline solution with oral rehydrating solution immediately increases plasma volume, serum osmolality, sodium and chloride seric concentrations, rhythm of glomerular filtration, urinary flow, restoring the volume of extracellular fluid after 24 h constituting a practical and economical alternative to the use of large volumes of isotonic saline solution.