A 58-year-old man with schizophrenia is brought to the clinic because of fatigue and mild confusion. He reports drinking water almost continuously throughout the day. Laboratory studies show sodium 126 mEq/L, serum osmolality 265 mOsm/kg, and urine osmolality 65 mOsm/kg. Which of the following is the most likely explanation for this hyponatremia?
- A)SIADH causing inappropriate water retention
- B)Osmotic diuresis due to hyperglycemia
- C)Hypoaldosteronism causing renal sodium wasting
- D)Primary polydipsia causing dilution of serum sodiumGABARITO
- E)Nephrogenic diabetes insipidus causing free water loss
Explicação
Primary polydipsia causes excessive water intake that lowers serum sodium. The very dilute urine indicates appropriate suppression of ADH. Ver explicação completa e trilha adaptativa →