From the Research
Diagnostic Approach
The diagnostic approach to hyponatremia involves categorizing patients according to their fluid volume status, including hypovolemic hyponatremia, euvolemic hyponatremia, or hypervolemic hyponatremia 1. The minimum diagnostic workup for hyponatremia includes sodium and osmolality measurement in plasma and urine, and the clinical evaluation of volume status 2.
Key Components of Workup
Key components of the workup for hyponatremia include:
- Measurement of serum sodium level
- Assessment of fluid volume status
- Measurement of serum osmolality
- Measurement of urine osmolality and sodium level
- Clinical evaluation of the patient's symptoms and signs
Treatment Approach
The treatment approach to hyponatremia depends on the underlying cause and the severity of symptoms. For most patients, the approach to managing hyponatremia should consist of treating the underlying cause 1. Urea and vaptans can be effective treatments for the syndrome of inappropriate antidiuresis and hyponatremia in patients with heart failure, but have adverse effects 1. Hypertonic saline is reserved for patients with severely symptomatic hyponatremia 1, 3, 4.
Symptom Severity and Onset
The severity of hyponatremia-induced neurological manifestation and the risk of poor outcome is mainly driven by the rapidity of serum sodium decrease 3. Therefore, emergency treatment of hyponatremia should be guided by symptom severity and the assumed onset of hyponatremia development, distinguishing acute (<48 hours) versus chronic hyponatremia (>48 hours) 3.
Importance of Proper Workup and Treatment
A proper diagnostic workup and treatment are important for the successful management of hyponatremia, especially in profound hyponatremia 2. The chance of receiving treatment for hyponatremia was higher in patients with a complete minimum diagnostic workup compared to those without 2. A multivariate analysis showed significantly better survival for treated patients compared to those not treated 2.