Review Question - QID 213535

This patient has severe hyponatremia as indicated by her sodium levels, confusion, lethargy, and seizure. In the case of hyponatremia with significant symptoms (e.g., seizure), patients are treated with hypertonic saline solution to slowly increase the serum sodium.

Hyponatremia describes the condition of low sodium concentration in the blood and is usually defined as a sodium concentration less than 135 mmol/L. The condition can result from various causes and is usually classified by the volume status. Low volume hyponatremia can occur secondary to diarrhea, vomiting, diuretics, or sweating (e.g., athletes). Normal volume hyponatremia can result from drinking too much water, hypothyroidism, SIADH, and adrenal insufficiency. High volume hyponatremia can occur from heart failure, liver failure, and kidney failure. Symptoms vary depending on the severity and can range from headaches and nausea to confusion, seizures, and coma. Treatment typically involves fluids to correct the sodium concentration slowly (4-6 mEq/L over the first 24 hours) to avoid central pontine myelinolysis. In patients with severe hyponatremia with symptoms such as confusion, convulsions, or coma, hypertonic saline is indicated.

Incorrect Answers:
Answer 1: Increasing the serum potassium with potassium solution is correct in the sense that this patient is hypokalemic. However, her symptoms are not explained by a low potassium level, and thus correcting the hypokalemia is not the best treatment for her current condition.

Answer 3: Increasing the serum sodium slowly with normal saline solution is the usual standard of care in patients with hypovolemic hyponatremia. However, given this patient’s severe symptoms (i.e., confusion and seizures), hypertonic saline solution is indicated.

Answer 4: Restricting fluids is the treatment for SIADH, a type of euvolemic hyponatremia. This patient’s hyponatremia likely resulted from fluid losses from her continuous diarrhea.

Answer 5: Starting the patient on maintenance anti-epileptic medications is probably not the best course of action as her seizure is likely secondary to hyponatremia. Correcting the underlying electrolyte balance will resolve the problem.

Bullet Summary:
Patients who present with symptomatic hyponatremia (e.g., confusion, headache, seizure) can be treated with slow correction of serum sodium via either normal saline or hypertonic saline (if severe symptoms are present).