HYPERNATREMIA-HYPOVOLEMIC HYPERNATREMIA

SUMMARY

1. Low volume implies water and total body Na⁺ loss (water deficit exceeding Na⁺ deficit).

2. Treat severe hypovolemic hypematremia with normal saline first to correct the volume deficit, and only then with hypotonic fluids to further replace the water deficit.

3. The amount of free water needed in a hypematremic patient is calculated by:
Vol_water = 0.6 * body weight * [(serum Na⁺-140)/140]

4. This usually is given over 1-2 days to decrease the sodium concentration at a rate of 0.5 mEq/L/hr or 10-12 mEq/L/day.

Reference(s)

Wilkinson, I. (2017). Oxford handbook of clinical medicine. Oxford: Oxford University Press.
Hannaman, R. A., Bullock, L., Hatchell, C. A., & Yoffe, M. (2016). Internal medicine review core curriculum, 2017-2018. CO Springs, CO: MedStudy.
Therapeutic Guidelines. Melbourne: Therapeutic Guidelines Limited. https://www.tg.org.au [Accessed 2021].