Hypernatremia is an elevated serum sodium level. It is commonly caused by sodium gain or water loss exceeding sodium loss.
Classification of hypernatremia
| Category | Description |
|---|---|
| Hypovolaemic hypernatremia | Gastrointestinal losses – diarrhea, vomiting, or fistulas; renal losses – diabetes inspidus; cutaneous losses – burns or profuse sweating |
| Euvolaemic hypernatremia | Inadequate water intake, hypodipsia, and adipsia |
| Hypervolaemic hypernatremia | Sodium overload; mineralocorticoid excess – Conn’s syndrome or Cushing’s syndrome |
- Signs and symptoms
- Lethargy
- Irritability
- Seizures and coma – due to cellular dehydration
- Differentials
- Hyperosmolar hyperglycaemic state
- Diabetes inspidus
- Treatment
- Assess volume status
- Fluid resuscitation with 0.9% saline if hypovolaemic
- This causes less marked fluid shifts and is hypotonic in hypertonic patients
- Cautious fluid restriction or use of diuretics if euvolaemiac or hypervolaemic
- Careful correction of sodium concentration
- Give water orally if possible
- Use hypotonic fluids such as 0.45% saline or 5% dextrose if water cannot be given orally
- The rate of correction should not exceed 10 mmol/L in a 24-hour period
- Frequently monitor serum electrolytes and vitals