What are the recommended labs and treatment for a patient with Addison's disease presenting to the hospital with nausea and vomiting?

Management of Addison's Disease Patient Hospitalized with Nausea and Vomiting

Immediately administer hydrocortisone 100 mg IV bolus and begin aggressive fluid resuscitation with 0.9% saline at 1 liter over the first hour—this patient is in or approaching adrenal crisis and treatment must not be delayed. 1, 2, 3

Immediate Laboratory Workup

Draw blood samples before administering hydrocortisone if possible, but never delay treatment waiting for results: 1, 2

• Serum cortisol and ACTH (cortisol <250 nmol/L with elevated ACTH confirms primary adrenal insufficiency) 2, 3
• Serum electrolytes (expect hyponatremia in ~90% of cases, hyperkalemia in ~50%) 2, 3
• Creatinine and BUN (typically elevated from prerenal azotemia due to volume depletion) 2
• Glucose (hypoglycemia more common in children but can occur in adults) 2
• Complete blood count 4

Additional labs to consider if etiology unknown:

• 21-hydroxylase autoantibodies (21OH-Ab) to confirm autoimmune Addison's disease (~85% of cases in Western populations) 4, 2, 3
• CT scan of adrenals if 21OH-Ab negative, to evaluate for hemorrhage, tumor, tuberculosis, or infiltrative processes 2, 3

Emergency Treatment Protocol

Initial Management (First Hour)

Glucocorticoid replacement: 1, 2, 3

• Hydrocortisone 100 mg IV bolus immediately
• This high dose provides both glucocorticoid and mineralocorticoid effects (saturates 11β-hydroxysteroid dehydrogenase type 2)
• Do not add fludrocortisone during acute crisis—the high-dose hydrocortisone provides adequate mineralocorticoid activity 2

Fluid resuscitation: 1, 2, 3

• 0.9% isotonic saline 1 liter IV over first hour
• Continue with 3-4 liters total over 24-48 hours with frequent hemodynamic monitoring
• Monitor closely to avoid fluid overload

Ongoing Management (Next 24-48 Hours)

Continue hydrocortisone: 1, 2, 3

• 100-300 mg/day either as:
  • Continuous IV infusion, OR
  • Divided IV/IM boluses of 100 mg every 6-8 hours

Monitor frequently: 2, 3

• Serum electrolytes every 4-6 hours initially
• Blood pressure and hemodynamic status
• Urine output
• Mental status

Identify and treat precipitating cause: 4, 2

• Gastrointestinal illness is the most common trigger
• Infection (obtain cultures, start antibiotics if indicated)
• Medication non-compliance
• Trauma or surgical stress

Common Pitfalls to Avoid

• Never delay treatment for diagnostic confirmation—mortality increases with delayed intervention 1, 2, 3
• Do not assume absence of hyperkalemia excludes crisis—it's only present in 50% of cases 2, 3
• Do not start thyroid hormone replacement before adequate glucocorticoid replacement in patients with multiple hormone deficiencies, as this can trigger crisis 1, 2
• Even mild nausea/vomiting can precipitate crisis because patients cannot absorb oral medications when they need them most 2

Transition to Maintenance Therapy

Once the patient is stable and can tolerate oral intake (typically 1-3 days): 1, 2

Taper parenteral hydrocortisone to oral therapy: 1, 3

• Hydrocortisone 15-25 mg daily divided into 2-3 doses (preferred over longer-acting agents like prednisone)
• Weight-adjusted dosing: starting doses 15-20 mg for hydrocortisone 5

Restart fludrocortisone when hydrocortisone dose falls below 50 mg/day: 2, 6

• Usual dose: 0.1 mg daily (range 0.05-0.2 mg daily)
• Adjust based on blood pressure and electrolytes
• If hypertension develops, reduce to 0.05 mg daily 4, 6

Prevention of Future Crises

Patient education is paramount: 1, 2, 3

• Double or triple oral glucocorticoid doses during minor illness (fever, gastroenteritis, upper respiratory infection) 1, 2
• Use parenteral hydrocortisone during severe illness or inability to take oral medications 1, 2
• Provide emergency supplies including injectable hydrocortisone 1, 3
• Medical alert jewelry and emergency steroid card 1, 3

Arrange endocrinology follow-up: 1, 3

• Education on emergency injectables
• Annual monitoring of weight, blood pressure, electrolytes 4, 3
• Screen for other autoimmune conditions (especially hypothyroidism) 4

Investigate causes of recurrent crises: 2

• Chronic under-replacement with fludrocortisone
• Low salt consumption
• Poor medication compliance
• Underlying psychiatric disorders