What are the treatment guidelines for hyponatremia?

Updated: Jun 17, 2019
  • Author: Eric E Simon, MD; Chief Editor: Vecihi Batuman, MD, FASN  more...
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Answer

For hyponatremia (acute or chronic) with severe symptoms, guideline statements include the following:

  • Promptly infuse 150  ml of 3% hypertonic saline IV over 20  min.

  • Consider checking the serum sodium concentration after 20  min while repeating an infusion of 150  ml 3% hypertonic saline for the next 20 min.

  • Consider repeating the above two steps twice or until achieving a 5  mmol/L increase in serum sodium concentration.

  • Manage patients with severely symptomatic hyponatremia in an environment where close biochemical and clinical monitoring can be provided.

For patients whose symptoms improve after a 5- mmol/L increase in serum sodium concentration in the first hour, guideline statements include the following:

  • Stop the infusion of hypertonic saline.
  • Keep the IV line open by infusing the smallest feasible volume of 0.9% saline until cause-specific treatment is started.

  • Start a diagnosis-specific treatment if available, aiming at least to stabilize the sodium concentration.

  • Limit the increase in serum sodium concentration to a total of 10 mmol/L during the first 24  h and an additional 8  mmol/during every 24 h thereafter until the serum sodium concentration reaches 130 mmol/L.

  • Consider checking the serum sodium concentration after 6 and 12  h and daily afterwards until the serum sodium concentration has stabilized under stable treatment.

For patients whose symptoms show no improvement after a 5- mmol/L increase in serum sodium concentration in the first hour, guideline statements include the following:

  • Continue an IV infusion of 3% hypertonic saline or equivalent, aiming for an additional 1 mmol/L per h increase in serum sodium concentration.

  • Stop the infusion of 3% hypertonic saline or equivalent when the symptoms improve, the serum sodium concentration increases 10 mmol/L in total, or the serum sodium concentration reaches 130  mmol/l, whichever occurs first.

  •  Start additional diagnostic exploration for other causes of the symptoms than hyponatremia.

  • Consider checking the serum sodium concentration every 4  h as long as an IV infusion of 3% hypertonic saline or equivalent is continued. 

For treatment of acute hyponatremia in patients without severe or moderately severe symptoms, guideline statements include the following:

  • Make sure that the serum sodium concentration has been measured using the same technique used for the previous measurement and that no administrative errors in sample handling have occurred.
  • If possible, stop fluids, medications, and other factors that can contribute to or provoke hyponatremia.

  • Start prompt diagnostic assessment.

  • Provide cause-specific treatment.

  • If the acute decrease in serum sodium concentration exceeds 10  mmol/L, consider giving a single IV infusion of 150  ml 3% hypertonic saline or equivalent over 20  min.

  • Consider checking the serum sodium concentration after 4 h, using the same technique as used for the previous measurement. 

For treatment of chronic hyponatremia in patients without severe or moderately severe symptoms, guideline statements on general management include the following:

  • Stop non-essential fluids, medications, and other factors that can contribute to or provoke hyponatremia.

  • Provide cause-specific treatment.

  • In mild hyponatremia, consider not providing treatment with the sole aim of increasing the serum sodium concentration.

  • In moderate or profound hyponatremia, avoid an increase in serum sodium concentration of >10  mmol/L during the first 24 h and >8  mmol/L during every 24  h thereafter.

In moderate or profound hyponatremia, consider checking the serum sodium concentration every 6  h until the serum sodium concentration has stabilized under stable treatment.

  • In cases of unresolved hyponatremia, reconsider the diagnostic algorithm and ask for expert advice.

 For patients with expanded extracellular fluid, guideline statements include the following:

  • Do not treat with the sole aim of increasing the serum sodium concentration in mild or moderate hyponatremia.
  • Consider fluid restriction to prevent further fluid overload.

  • Do not administer vasopressin receptor antagonists.

  • Do not administer demeclocycline.

For patients with SIADH, guideline statements include the following:

  • In moderate or profound hyponatremia, consider restricting fluid intake as first-line treatment.

  • In moderate or profound hyponatremia, consider the following as equivalent second-line treatments: increasing solute intake with 0.25–0.50  g/kg per day of urea or a combination of low-dose loop diuretics and oral sodium chloride.

  • In moderate or profound hyponatremia, do not administer lithium or demeclocycline.

  • In moderate hyponatremia, do not adminster vasopressin receptor antagonists.

  • In profound hyponatremia, do not administer vasopressin receptor antagonists.

For patients with reduced circulating volume, , guideline statements include the following:

  • Restore extracellular volume with an IV infusion of 0.9% saline or a balanced crystalloid solution at 0.5–1.0 ml/kg/h.

  • Manage patients with hemodynamic instability in an environment where close biochemical and clinical monitoring can be provided.

  • In cases of hemodynamic instability, the need for rapid fluid resuscitation overrides the risk of an overly rapid increase in serum sodium concentration. 

 if hyponatremia is corrected too rapidly, the guidelines recommend the following:

  • Promptly intervene to re-lower the serum sodium concentration if it increases >10  mmol/L during the first 24  h or >8  mmol/L in any 24  h thereafter.

  • Discontinue the ongoing active treatment. 

  • Consult an expert to discuss whether it is appropriate to start an infusion of 10 mL/kg of electrolyte-free water (eg, glucose solutions) over 1 h, with strict monitoring of urine output and fluid balance.

  • Consult an expert to discuss whether it is appropriate to add IV desmopressin 2  μg, not to be repeated more frequently than every 8  h. 


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