A 16-year-old obese adolescent with no prior medical history…

A 16-yeаr-оld оbese аdоlescent with no prior medicаl history presents with a 2-week history of polyuria and polydipsia and now has progressive confusion and inability to walk. Glucose is 1,240 mg/dL, Na 158 mEq/L, K 4.1 mEq/L, HCO3 19 mEq/L, pH 7.30, effective osmolality 374 mOsm/kg. There are no Kussmaul respirations and no fruity breath. Which represents the most appropriate initial management priority?