The treatment of hyponatremia is guided by the cause of it. In all cases, there is a relative increase in the total water amount in relation to the total sodium in the body.

In the cases of intravascular volume depletion with hyponatremia, the total loss of sodium is greater than the total loss of water. The resulting intravascular volume depletion causes an increase in the secretion of antidiuretic hormone (ADH) which limits the loss of water. Providing a normotonic (same tonicity as plasma) intravascular sodium solution (like 0.9% sodium chloride) will limit the ADH secretion and will allow the recovery of the total sodium level and the excretion of excess water.

When there is a relative intravascular volume depletion or “hypervolemic hyponatremia” as in decompensated heart failure with volume overload, the use of diuretics such as Lasix (which act at the loop of Henle of the renal tubule) may allow more loss of water than sodium through the urine. In the case of cirrhosis, the use of albumin can provide the necessary increase in the oncotic pressure of the plasma, to improve the intravascular space¹ and reduce ADH secretion.

In the event of hypertonic hyponatremia, the treatment is the removal of the substance causing the hypertonicity. The classic example of this is hyperglycemia. Insulin will correct the hyperglycemia and in doing so, the hyponatremia. The water that left the cells for the extracellular space when there was a high glucose concentration, will return to the intracellular space after the glucose level is corrected. When the hypertonicity is caused by mannitol or glycine, once the substance is cleared from the body, the sodium level will correct.

If the cause of the hyponatremia is the inappropriate secretion of ADH, the treatment of hyponatremia should be directed at limiting the intake of water. Sometimes medications such as demeclocycline² and V2 receptor blockers (conivaptan, tolvaptan)³ will allow for the necessary water clearance through the urine.

In all cases, in order to avoid the problem to become worse, electrolyte-free fluid intake should be limited. If the sodium level is below 115 mEq/L the use of hypertonic sodium solutions should be considered in order to reduce the risks of worsening encephalopathy and seizures, which can lead to death. In all cases and specially in subacute or chronic hyponatremia, the correction of the sodium limited should be limited to a maximum and 10 mEq/L per day, in order to reduce the risk of osmotic demyelination syndrome (ODS), which can lead to brain stem lesions leading to quadriplegia or locked-in syndrome.

Marco A. Ramos MD, CCDS

References

1. Robert Gianotti and Andres Cardenas, “Hyponatraemia and cirrhosis,” Gastroenterology Report 2, no. 1 (2014): 21-6. https://doi.org/10.1093/gastro/got037

2. Marleen Kortenoeven, Anne Sinke, Niels Hadrup, Christiane Trimpert, Jack Wetzels, Robert Fenton, and Peter Deen, “Demeclocycline attenuates hyponatremia by reducing aquaporin-2 expression in the renal inner medulla.,” American Journal of Physiology Renal Physiology 305, no. 12 (2013): F1705–18. https://doi.org/10.1152/ajprenal.00723.2012

3. Suruchi Aditya and Aditya Rattan, “Vaptans: A new option in the management of hyponatremia,” International Journal Applied Basic Medical Research 2, no. 2 (2012): 77-83. http://www.ijabmr.org/text.asp?2012/2/2/77/106347

Any information or statement present in this post does not replace your health care provider’s advice or treatment. This blog does not provide medical advice, prescribe medications or therapies, or diagnose conditions, it only expresses an opinion. If you have a health-related question or condition, confer with your healthcare provider.

- In order to quote from this article please use the following:

Marco A. Ramos, “Hyponatremia for Everyone. #7. Treatment of Hyponatremia,” SMO Blog (blog), September 5, 2018, https://steemit.com/health/@secondmedicalop/hyponatremia-for-everyone-7-treatment-of-hyponatremia

Read the other sections of this series:

Introduction
What Causes Hyponatremia? A
What Causes Hyponatremia? B
What Causes Hyponatremia? C
What Causes Hyponatremia? D
How Common is Hyponatremia?
What Happens when Someone has Hyponatremia?
Signs and Symptoms of Hyponatremia
Diagnosis and Tests used in Hyponatremia

Picture purchased and downloaded from istockphoto.com under a standard license Author: Nerthuz