Hyponatremia Pearls

Here are a few random pearls that I took away from yesterday's combined Beth Israel-Brigham-Mass General renal fellows' educational talk by Burton Rose a.k.a. "The Up-To-Date Guy" and author of the highly-recommended "Clinical Physiology of Acid-Base and Electrolyte Disorders".

1. The individuals who are the most susceptible to osmotic demyelination with overcorrection of hyponatremia are, for reasons which are as-yet unclear, young pre-menopausal women.

2. Hypernatremia is almost always caused by a defective thirst mechanism. Hyponatremia is almost always caused by an elevated ADH.

3. There are cases of osmotic demyelination which have been reported with only normal saline repletion of hypovolemic hyponatremia. In hypovolemic hyponatremia, a significant decrease in intravascular volume stimulates secretion of ADH; once a patient is euvolemic the ADH secretion should stop abruptly and the patient may experience an abrupt water diuresis. If the sodium is increasing too rapidly, one school of thought is that DDAVP should be given to limit the rate of sodium rise.

4. The reason that pretzels and peanuts are served at bars is to raise your sodium concentration enough to stimulate the thirst mechanism for you to want to order a tasty adult beverage.