From the Guidelines
Hypernatremia is primarily caused by water loss exceeding sodium loss or excessive sodium intake, with common causes including inadequate water intake, excessive water loss through vomiting or diarrhea, certain medications, and diabetes insipidus. The condition occurs when sodium levels in the blood exceed 145 mEq/L. According to the most recent evidence 1, hypernatremia can be caused by various factors, including:
- Inadequate water intake, especially in elderly or disabled individuals
- Excessive water loss through prolonged vomiting, severe diarrhea, or excessive sweating
- Certain medications, such as diuretics
- Diabetes insipidus, a condition characterized by the inability to regulate fluids in the body
- Iatrogenic causes, such as hypertonic saline administration Treatment of hypernatremia focuses on addressing the underlying cause while carefully correcting sodium levels. The cornerstone of treatment is controlled rehydration with hypotonic fluids like 5% dextrose in water or 0.45% saline. Correction should be gradual, typically not exceeding 10 mEq/L per day to prevent cerebral edema and neurological complications, as recommended by 1. For mild cases in alert patients who can drink, oral rehydration may suffice. Severe cases require intravenous fluids with careful monitoring of serum sodium levels, urine output, and neurological status. Patients with diabetes insipidus may need desmopressin (DDAVP) at doses of 1-2 mcg IV/SC or 10-20 mcg intranasally twice daily. Prevention strategies include ensuring adequate fluid intake in vulnerable populations and close monitoring of sodium levels in hospitalized patients receiving IV fluids or medications that affect sodium balance.
From the Research
Causes of Hypernatremia
- Hypernatremia is defined as a serum sodium level above 145 mmol/L [ 2 ]
- The human body maintains a normal osmolality between 280 and 295 mOsm/kg via Arginine Vasopressin (AVP), thirst, and the renal response to AVP; dysfunction of all three of these factors can cause hypernatremia [ 2 ]
- Hypernatremia can be caused by various pathogenetic mechanisms, including hypovolemic and hypervolemic hypernatremia [ 3 ]
Treatment of Hypernatremia
- Accurate diagnosis and appropriate treatment is crucial since undercorrection or overcorrection of hypernatremia are both associated with poor patients' prognosis [ 3 ]
- A detailed algorithm for the proper correction of hypernatremia is necessary for the management of this important electrolyte disorder [ 3 ]
- Evaluation of patients with increased sodium levels requires specific directions, and practical clues are necessary for the proper evaluation and treatment of hypovolemic and hypervolemic hypernatremia [ 3 ]
Key Considerations
- Hypernatremia is a frequently encountered electrolyte disturbance in the hospital setting, with an unappreciated high mortality [ 2 ]
- Understanding hypernatremia requires a comprehension of body fluid compartments, as well as concepts of the preservation of normal body water balance [ 2 ]
- Hypernatremia is a common electrolyte disorder with increased morbidity and mortality especially in the elderly and critically ill patients [ 3 ]