From the Guidelines
3% Normal Saline (NS) is not entirely safe in hyponatremia and should be reserved for severely symptomatic acute hyponatremia.
Key Considerations
- The use of hypertonic sodium chloride (3%) administration may improve hyponatremia but can worsen fluid overload and ascites, and should be limited to severely symptomatic cases 1.
- The goal of correction should be to increase serum sodium by up to 5 mmol/L in the first hour, with a limit of 8-10 mmol/L every 24 hours thereafter, to avoid central pontine myelinolysis 1.
- Hypertonic saline should be used with caution, especially in patients with cirrhosis, as rapid correction of hyponatremia can lead to more complications than the hyponatremia itself 1.
Clinical Guidelines
- The American Association for the Study of Liver Diseases recommends the use of hypertonic saline for short-term treatment of patients with symptomatic or severe hyponatremia, or those with imminent liver transplant 1.
- The European Association for the Study of the Liver suggests that hypertonic sodium chloride administration should be reserved for severely symptomatic hyponatremia, and that serum sodium should be slowly corrected to avoid central pontine myelinolysis 1.
Important Notes
- Patients with cirrhosis and ascites usually do not have symptoms from hyponatremia until the sodium is 110 mmol/L or unless the decline in sodium is very rapid 1.
- The use of vasopressin receptor antagonists, such as conivaptan and tolvaptan, may be considered for the treatment of hyponatremia in cirrhosis, but their effectiveness and safety in this setting are still being studied 1.
From the Research
Safety of 3% Normal Saline in Hyponatremia
- The use of 3% hypertonic saline is recommended for the treatment of severe hyponatremia, especially in patients with severe symptoms such as delirium, confusion, and seizures 2, 3.
- However, the safety of 3% normal saline in hyponatremia is not directly addressed in the provided studies, as they focus on the use of 3% hypertonic saline.
- Normal saline is used to treat hypovolemic hyponatremia, but its use in severe hyponatremia is not recommended due to the risk of delayed correction and increased length of stay 4.
Treatment of Severe Hyponatremia
- Severe hyponatremia is typically treated with 3% hypertonic saline to rapidly increase serum sodium levels and prevent further brain damage 2, 3, 5.
- The use of 3% hypertonic saline has been shown to be safe and effective in correcting severe hyponatremia, with a low risk of adverse events 3, 6.
- The combination of 3% hypertonic saline and desmopressin has been proposed as a strategy for correcting severe hyponatremia while avoiding overcorrection 6.
Comparison of 3% Hypertonic Saline and Normal Saline
- A retrospective study compared the use of 3% hypertonic saline and normal saline in patients with severe hyponatremia, and found that hypertonic saline was associated with a faster correction of serum sodium levels and a shorter length of stay 4.
- However, normal saline was still used in the majority of patients, despite the recommendation for hypertonic saline in severe hyponatremia 4.