emDocs - January 13, 2020 - By Desai N and Jang D
Reviewed by: Koyfman A; Montrief T; Long B
"Pearls:
- Rate of serum sodium concentration change is far more important to quantify than the numerical number itself. Rely on symptoms and good history taking skills.
- Just because you can correct acute hyponatremia quickly does not mean you should. Aim for a 4-6 mEq/L increase in the first six hours of treatment if the patient has signs of CNS dysfunction listed above. Do not correct greater than 6 mEq/L in the first 24 hours to avoid the risk of osmotic demyelination syndrome.
- If you do not have ready access to hypertonic saline (100 cc of 3% hypertonic saline IV over 10 min), you can substitute with an ampule (50 ml) of bicarbonate (8.4% sodium bicarbonate).
- Confirm tonicity of fluid (hypo-, iso-, hyper-) prior to initiating treatment in the emergency department.
- Be comfortable with the use of desmopressin in the case of undifferentiated hyponatremia, severely hypovolemic hyponatremia and rapid overcorrection of hyponatremia. You can administer this concurrently during hypertonic or intravenous fluid administration for prophylactic measures.
Pitfalls:
- Be very cautious in administration of intravenous fluids (Lactate preferably over NaCl or 3% hypertonic) in patients with hypovolemic history (poor oral intake, diarrhea, increased NG tube output, vomiting) as they tend to overcorrect rapidly leading to an increased risk of osmotic demyelination syndrome. Be judicious with fluid challenges (250cc – 500cc per bolus).
- If you administer 3% hypertonic saline, pay close attention to the urine output and consider placing a foley early, urine output >100 cc/hr is an early red flag for overcorrection."