Would 25% albumin exacerbate hypo-osmolar hyponatremia?

From the Guidelines

No, 25% albumin would not worsen hypo-osmolar hyponatremia and may actually help in certain situations, as supported by the most recent guidance from the American Association for the Study of Liver Diseases in 2021 1. Albumin is an oncotically active protein that draws fluid into the intravascular space without significantly affecting serum sodium concentration. When 25% albumin is administered, it increases oncotic pressure in the blood vessels, which can help pull excess free water from the interstitial and intracellular spaces into the vasculature, potentially allowing for more effective removal of this free water through diuresis. This differs from hypotonic fluids like 5% dextrose or even isotonic saline, which can worsen hyponatremia by adding more free water relative to sodium.

Key Considerations

• In patients with hyponatremia associated with volume depletion or conditions like cirrhosis, 25% albumin may be beneficial as part of the treatment strategy, as indicated by recent practice guidance 1.
• Albumin alone is not a primary treatment for hyponatremia - addressing the underlying cause and potentially using hypertonic saline (3% NaCl) for severe symptomatic cases remains essential.
• The dose of albumin typically ranges from 25-50g (100-200mL of 25% solution) administered intravenously, but should be tailored to the specific clinical situation.
• Water restriction and cessation of diuretics are also recommended in the management of moderate to severe hyponatremia, with more severe restriction and albumin infusion considered for severe cases 1.

Clinical Context

The use of 25% albumin in the context of hypo-osmolar hyponatremia should be guided by the most recent clinical practice guidelines, which emphasize a cautious approach to correcting serum sodium levels to avoid osmotic demyelination syndrome (ODS) 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, as recommended by the American Association for the Study of Liver Diseases 1.

From the Research

Hypo-Osmolar Hyponatremia and 25% Albumin

• The use of 25% albumin in the treatment of hypo-osmolar hyponatremia is not directly addressed in the provided studies 2, 3, 4, 5, 6.
• However, it is known that hypo-osmolar hyponatremia is characterized by a low serum osmolality and a low serum sodium concentration.
• The treatment of hypo-osmolar hyponatremia typically involves correcting the underlying cause of the disorder, such as fluid restriction, hypertonic saline, or vasopressin receptor antagonists 2, 3, 4, 5, 6.
• The use of 25% albumin could potentially worsen hypo-osmolar hyponatremia if it increases the amount of free water in the body, leading to a further dilution of serum sodium.
• It is essential to monitor serum sodium levels closely and adjust treatment accordingly to avoid overly rapid correction, which can lead to osmotic demyelination 2, 5, 6.

Treatment of Hyponatremia

• The treatment of hyponatremia depends on the severity of symptoms, the underlying cause, and the presence of other electrolyte imbalances 2, 3, 4, 5, 6.
• Hypertonic saline is commonly used to treat moderate to severe hyponatremia, especially in patients with symptoms such as seizures or coma 3, 5, 6.
• Vasopressin receptor antagonists, such as vaptans, are also used to treat hyponatremia, particularly in patients with SIADH or other forms of vasopressin-induced hyponatremia 2, 4, 5.
• Fluid restriction is often used in combination with other treatments to manage hyponatremia, especially in patients with mild to moderate symptoms 2, 3, 4, 5, 6.