From the Guidelines
Hypernatremia is primarily caused by iatrogenic factors, particularly in vulnerable populations such as very low birth weight infants (VLBWI), resulting from incorrect replacement of transepidermal water loss, inadequate water intake, or excessive sodium intake. According to the espghan/espen/espr/cspen guidelines on pediatric parenteral nutrition 1, hypernatremia often arises from these preventable causes, emphasizing the need for careful assessment and management.
Key Causes of Hypernatremia
- Incorrect replacement of transepidermal water loss (TEWL)
- Inadequate water intake
- Excessive sodium intake, which can be inadvertent during the transition phase These causes highlight the importance of monitoring and adjusting fluid and electrolyte balances, especially in high-risk groups like VLBWI.
Considerations for Management
- Assessment of the infant's intravascular volume and hydration status is crucial for determining the appropriate therapeutic measures 1.
- In cases of symptomatic hypovolaemia, replacing plasma volume is necessary.
- A reduction rate of 10-15 mmol/L/24h is recommended for correcting hypernatremia to avoid complications such as cerebral edema, seizures, and neurological injury 1.
From the Research
Causes of Hypernatremia
- Hypernatremia is often caused by dehydration resulting from an impaired thirst mechanism or lack of access to water 2
- Other causes of hypernatremia include diabetes insipidus 2, 3, 4
- Excessive sodium intake is a rare cause of hypernatremia 3
- Essential hypernatremia is a rare condition characterized by chronic and sustained hypernatremia, absence of thirst, and normal renal function 4
- Hypernatremia can also be caused by an imbalance in the water balance of the body, often resulting from an increased loss of free water compared to sodium excretion 3
Clinical Presentation of Hypernatremia
- The clinical presentation of hypernatremia is often characterized by central nervous system dysfunction, such as confusion and coma 3
- Pronounced thirst is also a common symptom of hypernatremia, although some patients may have impaired thirst mechanisms 3
- Other symptoms of hypernatremia may include delirium, impaired consciousness, and seizures 2
Diagnosis and Treatment of Hypernatremia
- The diagnosis of hypernatremia is based on medical history, volume status, and osmolality of urine 3
- Treatment of hypernatremia typically involves addressing the underlying cause and replacing the loss of free water with hypotonic infusions 2, 3
- Desmopressin acetate may be effective in treating essential hypernatremia and central diabetes insipidus 4, 5
- Close laboratory controls are important to avoid rapid changes in serum sodium concentration, which can have deleterious consequences 3