From the Guidelines

Hyponatremia should be approached with caution, considering the etiology, chronicity, severity, and urgency of the condition.

The treatment of hyponatremia depends on the underlying cause, with hypovolemic hyponatremia typically managed with fluid resuscitation using 5% IV albumin or crystalloid solution, and euvolemic hyponatremia managed based on the specific underlying cause 1.
Hypervolemic hyponatremia is treated with fluid restriction, reduction or discontinuation of diuretics and laxatives, administration of hyperoncotic albumin, and/or vasopressin receptor antagonists (“vaptans”) 1.

Mild hyponatremia (Na 126-135 mEq/L) in cirrhosis without symptoms does not require specific management apart from monitoring and water restriction 1.
Moderate hyponatremia (120-125 mEq/L) is managed with water restriction to 1,000 mL/day and cessation of diuretics, while severe hyponatremia (<120 mEq/L) requires a more severe restriction of water intake with albumin infusion 1.

The goal rate of increase of serum sodium is 4-6 mEq/L per 24-hour period, not to exceed 8 mEq/L per 24-hour period to ameliorate the risk of osmotic demyelination syndrome (ODS) 1.

Vasopressin receptor antagonists can be used with caution for a short term (≤30 days) to raise serum sodium, and hypertonic saline is reserved for short-term treatment of patients with symptomatic or severe hyponatremia or those with imminent liver transplant (LT) 1.
Patients with hyponatremia who undergo LT are at an increased risk for postoperative complications, including infections, renal failure, and ODS, and multidisciplinary coordinated care may mitigate this risk 1.

From the Research

Hyponatremia is defined by a serum sodium level of less than 135 mEq/L and most commonly results from water retention 2.
The approach to managing hyponatremia should consist of treating the underlying cause, and patients should be categorized according to their fluid volume status (hypovolemic hyponatremia, euvolemic hyponatremia, or hypervolemic hyponatremia) 2.
For patients with severely symptomatic hyponatremia, treatment with bolus hypertonic saline is recommended to reverse hyponatremic encephalopathy by increasing the serum sodium level by 4 mEq/L to 6 mEq/L within 1 to 2 hours, but by no more than 10 mEq/L within the first 24 hours 2.

Urea and vaptans can be effective treatments for the syndrome of inappropriate antidiuresis and hyponatremia in patients with heart failure, but have adverse effects 2.
A staged approach is necessary for treating hyponatremia in older patients, with the best treatment being the elimination of the underlying cause 3.
The treatment algorithm should be simple and include recommendations for the correction rate, with caution needed to avoid the occurrence of an osmotic demyelination syndrome (ODS) 3.
For patients with mild symptoms, hyponatremia should be managed conservatively, with therapy aimed at removing the offending cause, while severe symptoms require more aggressive correction of the serum sodium concentration, typically with intravenous therapy in the inpatient setting 4.

Overly rapid correction of chronic hyponatremia may cause osmotic demyelination, a rare but severe neurological condition, which can result in parkinsonism, quadriparesis, or even death 2, 5.
Hyponatremia affects approximately 5% of adults and 35% of patients who are hospitalized, and most patients should be managed by treating their underlying disease and according to whether they have hypovolemic, euvolemic, or hypervolemic hyponatremia 2.
The correction rate of hyponatremia should be similar to the rate at which it developed, and caution is needed to avoid overly aggressive treatment 6, 4.