Salt Tablet Dosing for Hyponatremia with Sodium Level of 128 mmol/L
For a patient with a sodium level of 128 mmol/L, the recommended dose of oral sodium chloride is 100 mEq three times daily, combined with fluid restriction to 1 L/day. 1
Assessment and Classification
- Sodium level of 128 mmol/L represents mild hyponatremia (126-135 mmol/L) 2
- Before initiating treatment, determine volume status (hypovolemic, euvolemic, or hypervolemic) as this guides appropriate management 2
- Check urine sodium and osmolality to help distinguish between SIADH and other causes of hyponatremia 2
Treatment Approach Based on Volume Status
For Euvolemic Hyponatremia (e.g., SIADH)
- Implement fluid restriction to 1 L/day as first-line treatment 2, 1
- Add oral NaCl 100 mEq three times daily if fluid restriction alone is insufficient 1
- Consider high protein diet to augment solute intake 1
For Hypovolemic Hyponatremia
- Discontinue diuretics if they're contributing to hyponatremia 2
- Administer isotonic saline (0.9% NaCl) for volume repletion 2
- Once euvolemic, oral salt tablets may be added if needed 1
For Hypervolemic Hyponatremia (e.g., cirrhosis, heart failure)
- Implement fluid restriction to 1-1.5 L/day 2, 1
- Consider albumin infusion for patients with cirrhosis 2
- Avoid hypertonic saline unless life-threatening symptoms are present 2
Correction Rate Guidelines
- Target correction should not exceed 8 mmol/L in 24 hours to prevent osmotic demyelination syndrome 2, 1
- For patients with advanced liver disease, alcoholism, malnutrition, or prior encephalopathy, use more cautious correction (4-6 mmol/L per day) 2
- Monitor serum sodium every 4-6 hours during initial correction 1
Special Considerations
- Patients with mild hyponatremia (sodium 128 mmol/L) typically have mild or no symptoms 3
- Even mild hyponatremia is associated with cognitive impairment, gait disturbances, and increased rates of falls and fractures 4
- For patients with cirrhosis, sodium restriction and not fluid restriction results in weight loss as fluid passively follows the sodium 5
- Watch for signs of hyperkalemia when using oral sodium supplements, especially in patients with renal impairment 1
Monitoring and Follow-up
- Calculate sodium deficit using formula: Desired increase in Na (mEq/L) × (0.5 × ideal body weight in kg) 2, 1
- If overcorrection occurs, consider relowering with electrolyte-free water or desmopressin 2
- Watch for signs of osmotic demyelination syndrome (dysarthria, dysphagia, oculomotor dysfunction, quadriparesis) typically occurring 2-7 days after rapid correction 2