Hyponatremia: The Daily PANCE Blueprint
A 60-year-old male with a history of alcohol abuse and esophageal varices is brought to the ER with lethargy, delirium, weakness, and nausea. He is normotensive and afebrile. On physical exam, he is ill-appearing with jaundice, spider angiomas, a distended abdomen, and 3+ pretibial pitting edema. Based on his history and clinical presentation, which of the following electrolyte abnormalities would you expect to see in this patient?
A. Hyponatremia
B. Hypocalcemia
C. Hypercalcemia
D. Hyperphosphatemia
E. Hypermagnesemia
Answer and topic summary
The answer is A. Hyponatremia
The patient has hypervolemic hyponatremia secondary to cirrhosis. Causes of hypervolemic hyponatremia are cirrhosis, nephrotic syndrome, and CHF. Symptoms include nausea, headache, lethargy, seizures. It’s important to have an approach to hyponatremia since it is the most common electrolyte abnormality in the hospital.
- First, it’s important to rule out pseudohyponatremia due to proteins, glucose, or mannitol. Also, make sure it’s not a diuretic causing hyponatremia.
- Next, consider the volume status – are they hypervolemic, hypovolemic, or euvolemic?
- Hypovolemic causes are more obvious (emesis, hemorrhage, etc); however, urinary sodium can help differentiate between hypovolemia and euvolemia. If uNA < 20, then this means the renin-angiotensin-aldosterone system is on and trying to maintain pressure/volume; therefore, it is likely the patient is hypovolemic.
Treatment of hyponatremia depends on the cause. It usually involves fluid restriction and possibly (and carefully) a hypertonic solution. Remember – rapid correction of hyponatremia can lead to central pontine myelinolysis.
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Smarty PANCE Content Blueprint Review:
Covered under ⇒ PANCE Blueprint Renal System ⇒ ⇒
Also covered as part of the Internal Medicine EOR topic list
