Osmolarity And Osmolality Practice Test

A 38-year-old female (weight 58 kg) presents with severe diarrhea and muscle cramps. Medical history: irritable bowel syndrome; no renal or hepatic dysfunction. Current medications: dicyclomine 20 mg PO four times daily as needed. Labs: serum sodium 134 mEq/L (135–145), glucose 80 mg/dL (70–100), BUN 10 mg/dL (7–20). What is the calculated osmolarity of this patient's serum using $\text{Osm} = 2\times\text{Na} + \frac{\text{glucose}}{18} + \frac{\text{BUN}}{2.8}$?

A 74-year-old male (weight 72 kg) with chronic kidney disease stage 4 is admitted for uremic symptoms. Medical history: CKD, atrial fibrillation; no hepatic dysfunction. Current medications: apixaban 2.5 mg PO twice daily, carvedilol 12.5 mg PO twice daily. Labs: serum sodium 142 mEq/L (135–145), glucose 98 mg/dL (70–100), BUN 96 mg/dL (7–20). Which therapeutic intervention is indicated based on the osmolarity calculation if uremia is contributing to hyperosmolar state and symptoms?