At what serum sodium level does a patient require hospital admission due to hypernatremia (elevated sodium levels) or hyponatremia (low sodium levels)?

From the Guidelines

Patients with serum sodium levels below 120 mEq/L or those with symptomatic hyponatremia require hospital admission due to the risk of osmotic demyelination syndrome and other complications. The management of hyponatremia is crucial, and according to the 2021 practice guidance by the American Association for the Study of Liver Diseases 1, water restriction and cessation of diuretics are recommended for moderate hyponatremia (120-125 mEq/L). For severe hyponatremia (<120 mEq/L), a more severe restriction of water intake with albumin infusion is recommended.

Key Considerations

• 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.
• Severe hyponatremia (<120 mEq/L) at the time of liver transplantation increases the risk of ODS, and multidisciplinary coordinated care may mitigate this risk 1.
• The use of vasopressin receptor antagonists can raise serum sodium during treatment but should be used with caution only for a short term (≤30 days) 1.
• Hypertonic saline is reserved for short-term treatment of patients with symptomatic or severe hyponatremia or those with imminent liver transplantation 1.

Clinical Judgment

Admission decisions depend not just on the absolute sodium value but also on the rate of change, presence of symptoms, and underlying causes. Patients with moderate abnormalities may require admission if they show neurological symptoms like confusion, seizures, or altered mental status. The speed of sodium change is critical, and rapid shifts in either direction can cause cerebral edema or osmotic demyelination syndrome. Patients with chronic conditions may tolerate more extreme values without symptoms due to the brain's adaptation mechanisms. Treatment involves careful correction of sodium levels at appropriate rates using IV fluids, medication adjustments, and addressing underlying causes like medication effects, hormonal disorders, or fluid balance issues.

From the Research

Hospital Admission Criteria for Hypernatremia and Hyponatremia

• Patients with severe hyponatremia (serum sodium level less than 125 mEq/L) and severe symptoms, such as delirium, confusion, impaired consciousness, ataxia, seizures, or cardiorespiratory distress, require emergency infusions with 3% hypertonic saline and hospital admission 2, 3, 4.
• Patients with a serum sodium concentration of less than 120 mEq/L are considered to have severe hyponatremia and may require hospital admission 5, 4.
• Intensive treatment of hyponatremia starts at the level of plasmatic concentration of sodium under 120 mmol/l or when neurological symptoms of brain edema are present 4.
• For hypernatremia, treatment starts with addressing the underlying etiology and correcting the fluid deficit, and hospital admission may be required for patients with severe symptoms or those who require intravenous fluids 2.

Serum Sodium Levels and Hospital Admission

• Serum sodium levels less than 125 mEq/L with severe symptoms require hospital admission 2, 3.
• Serum sodium levels less than 120 mEq/L require intensive treatment and may require hospital admission 5, 4.
• The decision to admit a patient to the hospital due to hypernatremia or hyponatremia depends on the severity of symptoms, the underlying cause, and the patient's overall clinical condition 2, 3, 5, 4, 6.