Contributor: Aaron Lessen MD
Educational Pearls:
The case:
- A gentleman came in from a nursing home with symptoms concerning for sepsis. He was hypotensive, hypoxic, febrile, and mentally altered.
- His past medical history included previous strokes which had left him with deficits for which he required a feeding tube.
- Initial workup included some point of care labs which revealed a sodium of 165 mEq/L (normal range 135-145)
Hypernatremia
- What causes it?
- Dehydration, from insufficient fluid intake. This might happen in individuals who cannot drink water independently, such as infants, elderly, or disabled people, as was the case for this patient.
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Other causes of dehydration/hypernatremia include excessive sweating; diabetes insipidus; diuretic use; kidney dysfunction; and severe burns which can lead to fluid loss through the damaged skin.
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How do you correct it?
- Need to correct slowly, not more than 10 to 12 meq/L in 24 hours
- Can do normal saline (0.9%) or half saline (0.45%) and D5, at 150-200 mL per hour.
- Check the sodium frequently (every 2-3 hours)
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Will likely need ICU-level monitoring
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What happens if you correct it too quickly?
- Cerebral edema
- Seizures
Bonus fact: Correction of hyponatremia too quickly causes osmotic demyelination syndrome (ODS).
References
- Chauhan, K., Pattharanitima, P., Patel, N., Duffy, A., Saha, A., Chaudhary, K., Debnath, N., Van Vleck, T., Chan, L., Nadkarni, G. N., & Coca, S. G. (2019). Rate of Correction of Hypernatremia and Health Outcomes in Critically Ill Patients. Clinical journal of the American Society of Nephrology : CJASN, 14(5), 656–663. https://doi.org/10.2215/CJN.10640918
- Lindner, G., & Funk, G. C. (2013). Hypernatremia in critically ill patients. Journal of critical care, 28(2), 216.e11–216.e2.16E20. https://doi.org/10.1016/j.jcrc.2012.05.001
- Muhsin, S. A., & Mount, D. B. (2016). Diagnosis and treatment of hypernatremia. Best practice & research. Clinical endocrinology & metabolism, 30(2), 189–203. https://doi.org/10.1016/j.beem.2016.02.014
Summarized by Jeffrey Olson MS2 | Edited by Meg Joyce & Jorge Chalit, OMSIII