Effective Management of Hyponatremia: Guideline for Critical Care Pharmacists
As a critical care pharmacist, managing hyponatremia, the most common electrolyte disorder, is crucial. Hyponatremia is linked to increased mortality and can cause mental status changes and falls, even when mild.
Emergent Management, use 3% NaCl for severe symptoms like coma or seizures, whether hyponatremia is acute or chronic. Administer a 100 to 150 mL bolus over 10 to 20 minutes.
- Consider 3% NaCl for moderate symptoms, such as vomiting or confusion, in high-risk patients like marathon runners or those with intracranial injury.
- Don’t delay 3% NaCl for central line placement; data suggest low extravasation risk with peripheral use for a few days.
- Aim to raise sodium by 4 to 6 mEq/L in the first 1 to 2 hours. Avoid exceeding about 8 mEq/L in 24 hours to prevent osmotic demyelination syndrome.
Non-emergent Management, avoid routine 3% NaCl for asymptomatic or mildly symptomatic patients, such as those with gait changes. Treat based on the underlying cause.
- Use 0.9% NaCl for hypovolemic hyponatremia or diuresis for hypervolemic hyponatremia.
- For euvolemic patients with SIADH, try fluid restriction first. If ineffective, consider adding urea oral solution, an osmotic agent that increases water excretion. Urea is safe and raises sodium similarly to vaptans. However, note that there is no strong evidence that urea or vaptans improve quality of life or decrease mortality.
Take-home points
- Recognize that hyponatremia, the most common electrolyte disorder, is linked to increased mortality and can cause mental status changes and falls.
- Use 3% NaCl for severe hyponatremia symptoms like coma or seizures, whether the condition is acute or chronic.
- Administer a 100 to 150 mL bolus of 3% NaCl over 10 to 20 minutes for severe symptoms.
- Avoid routine 3% NaCl for asymptomatic or mildly symptomatic patients; treat based on the underlying cause.
- Consider fluid restriction and urea oral solution for euvolemic hyponatremia due to syndrome of inappropriate antidiuretic hormone (SIADH).
- Prevent osmotic demyelination syndrome by avoiding sodium increases of more than 8 mEq/L in 24 hours.
References
- Adrogué HJ, Tucker BM, Madias NE. Diagnosis and Management of Hyponatremia: A Review. JAMA. 2022;328(3):280-291. doi:10.1001/jama.2022.11176
- Spasovski G, Vanholder R, Allolio B, et al. Clinical practice guideline on diagnosis and treatment of hyponatraemia [published correction appears in Eur J Endocrinol. 2014 Jul;171(1):X1]. Eur J Endocrinol. 2014;170(3):G1-G47. Published 2014 Feb 25. doi:10.1530/EJE-13-1020
- Decaux G, Gankam Kengne F. Hypertonic saline, isotonic saline, water restriction, long loops diuretics, urea or vaptans to treat hyponatremia. Expert Rev Endocrinol Metab. 2020;15(3):195-214. doi:10.1080/17446651.2020.1755259
- Hoorn EJ, Spasovski G. Recent developments in the management of acute and chronic hyponatremia. Curr Opin Nephrol Hypertens. 2019;28(5):424-432. doi:10.1097/MNH.0000000000000528
Keywords: Hyponatremia management, Critical care pharmacy, 3% NaCl treatment, Severe hyponatremia, Euvolemic hyponatremia, SIADH treatment, Urea oral solution, Osmotic demyelination syndrome prevention
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