33-year-old woman is brought to the emergency department after an episode of generalized tonic-clonic seizures. She is confused
and unable to provide further history Review of the medical record indicates that she has schizophrenia but stopped taking all her
psychiatric medications 3 weeks ago. Temperature is 36.7 C (98 F), blood pressure is 130/76 mm Hg, pulse is 80/min, and
respirations are 14/min. Examination shows normal pupils The patient’s lungs are clear to auscultation and her heart sounds are
normal. Her abdomen is soft. Extremities examination shows no edema. Laboratory results are as follows:
Serum sodium 118 mEq/L
Serum potassium 3.4 mEq/L
Serum creatinine 0.8 mg/dl
Serum calciu m 8.4 mg/dl
Serum glucose 98 mg/dl
Serum osmolality 252 mOsm/kg
Urine osmolality 78 mOsm/kg
Urine specific gravity 1.002
Which of the following is the most likely cause of this patient’s electrolyte abnormalities?
- 0 A Adrenal insufficiency
- Q B. Fluoxetine-mediated hypothalamic antidiuretic hormone production
- Q C. Idiopathic central diabetes insipidus
- Q D. Idiopathic nephrogenic diabetes insipidus
- 0 E. Primary polydipsia
- Q F Syndrome of inappropriate antidiuretic hormone secretion due to lung cancer
0 voters