60-year-old man comes to the emergency department because of nausea, headache, and generalized fatigue for 2 days. He was diagnosed with small cell lung cancer around 3 months ago. Examination shows decreased breath sounds over the left lung. Cardiac examination shows an S4. The abdomen is soft and nontender. Neurological examination shows no focal findings. Further evaluation reveals an electrolyte abnormality induced by ectopic antidiuretic hormone production from a lung mass. This patient is at greatest risk of which of the following conditions if his electrolyte abnormality is corrected too quickly?

Question

60-year-old man comes to the emergency department because of nausea, headache, and generalized fatigue for 2 days. He was diagnosed with small cell lung cancer around 3 months ago. Examination shows decreased breath sounds over the left lung. Cardiac examination shows an S4. The abdomen is soft and nontender. Neurological examination shows no focal findings. Further evaluation reveals an electrolyte abnormality induced by ectopic antidiuretic hormone production from a lung mass.  This patient is at greatest risk of which of the following conditions if his electrolyte abnormality is corrected too quickly?

Quizplus · Accepted Answer

Eductional Objective: Rapid correction of chronic hyponatremia may lead to osmotic demyelination syndrome (also known as central pontine myelinolysis).  It typically manifests 2-6 days after the osmotic insult with spastic quadriplegia, pseudobulbar palsy, and locked-in syndrome.

60-Year-Old Man Comes to the Emergency Department Because of Nausea