How to correct hyponatremia (low sodium level) in a patient with adrenal crisis?

Management of Severe Hyponatremia in Adrenal Crisis

In a patient with adrenal crisis and severe hyponatremia (Na 115), sodium correction should be done slowly with isotonic saline at an initial rate of approximately 1 L/hr, followed by a slower infusion rate, while simultaneously administering hydrocortisone 100 mg IV bolus followed by 100-300 mg/day as continuous infusion or divided doses every 6 hours. 1, 2

Initial Management

1. Immediate interventions:

   • Administer hydrocortisone 100 mg IV bolus immediately 1
   • Begin isotonic (0.9%) saline infusion at approximately 1 L/hr initially 1
   • Monitor hemodynamic parameters and serum electrolytes frequently 1

2. Ongoing hydrocortisone administration:

   • Continue hydrocortisone 100-300 mg/day as continuous infusion or divided IV/IM doses every 6 hours 1
   • Maintain parenteral glucocorticoids for 1-3 days before tapering to oral therapy 1

Sodium Correction Principles

Target correction rates:

• Maximum correction: 8 mmol/L in 24 hours 2
• Initial target: 4-6 mmol/L in first 6 hours for severe symptoms 2
• Monitor serum sodium every 2-4 hours depending on symptom severity 2

Calculation for correction:

• Sodium deficit formula: Desired increase in Na (mEq) × (0.5 × ideal body weight in kg) 2
• For 3% saline (if needed for severe neurological symptoms): Infusion rate (mL/hr) = Sodium deficit (mEq) ÷ 513 mEq/L × 1000 mL/L ÷ hours of infusion 2

Monitoring and Adjustment

• Check serum sodium every 2 hours for severe symptoms, every 4 hours for mild symptoms 2
• Monitor urine output and specific gravity every 4 hours 2
• Watch for signs of water diuresis (sudden decrease in urine specific gravity ≥0.010) which can lead to overcorrection 2
• Adjust infusion rate based on sodium levels and clinical response 2

Prevention of Complications

• Osmotic demyelination syndrome risk: This potentially fatal neurological condition can occur if sodium correction exceeds 8 mmol/L in 24 hours 2
• If sodium increases too rapidly, consider administering hypotonic fluids to slow correction 2
• Be vigilant for high urine output which may signal water diuresis and lead to overcorrection 2

Special Considerations for Adrenal Crisis

• Restart mineralocorticoid replacement (fludrocortisone) when hydrocortisone dose falls below 50 mg/day 1
• Typical fludrocortisone dose is 0.1 mg daily (range 0.1 mg three times weekly to 0.2 mg daily) 3
• Continue IV fluids (3-4 L isotonic saline or 5% dextrose in isotonic saline) at a slower rate for 24-48 hours after initial resuscitation 1

Transitioning to Maintenance Therapy

• Taper parenteral glucocorticoids over 1-3 days as clinical condition improves 1
• Resume oral hydrocortisone and fludrocortisone when patient can tolerate oral intake 1
• Educate patient on increasing steroid doses during intercurrent illnesses to prevent future crises 1

Pitfalls to Avoid

• Delaying hydrocortisone administration while waiting for diagnostic test results 1
• Correcting sodium too rapidly (>8 mmol/L in 24 hours) 2
• Failing to monitor for water diuresis, which can cause sudden sodium elevation 2
• Overlooking the need to restart mineralocorticoid replacement when hydrocortisone dose is reduced 1
• Fluid restriction in adrenal crisis patients, which can worsen hypovolemia 1

Remember that adrenal crisis with severe hyponatremia requires careful management of both conditions simultaneously, with close monitoring to prevent complications from either undertreating the adrenal crisis or correcting the hyponatremia too rapidly.