What is the treatment for unilateral adrenal insufficiency?

Treatment of Unilateral Adrenal Insufficiency

The treatment for unilateral adrenal insufficiency involves surgical resection of the affected adrenal gland (adrenalectomy) when the condition is caused by a functioning adrenal mass, with minimally invasive surgery being the preferred approach when feasible. 1

Diagnostic Approach

Before initiating treatment, proper diagnosis is essential:

1. Biochemical confirmation:

   • Morning serum cortisol and plasma ACTH measurements
   • Synacthen (tetracosactide) stimulation test if results are equivocal (peak serum cortisol <500 nmol/L is diagnostic of adrenal insufficiency) 1

2. Imaging:

   • Adrenal protocol CT scan or MRI to determine size, heterogeneity, lipid content, and margin characteristics 1
   • Assess for features suggesting malignancy (irregular margins, inhomogeneous appearance, size >4 cm)

3. Functional evaluation:

   • Test for hormone excess: plasma aldosterone/renin activity, serum ACTH, cortisol, DHEA-S, and fractionated plasma-free metanephrines 1

Treatment Algorithm

1. For Functioning Unilateral Adrenal Masses

• Cortisol-secreting adrenal masses:

  • Patients with unilateral cortisol-secreting adrenal masses and clinically apparent Cushing's syndrome should undergo unilateral adrenalectomy of the affected gland 1
  • Minimally-invasive surgery (laparoscopic approach) is preferred when feasible 1
  • Younger patients with mild autonomous cortisol secretion (MACS) who have progressive metabolic comorbidities can be considered for adrenalectomy 1

• Aldosterone-secreting adenomas:

  • Adrenalectomy should be performed for patients with unilateral aldosterone-secreting adrenal masses 1
  • Adrenal vein sampling may be necessary to confirm unilateral production 1

• Pheochromocytomas:

  • Adrenalectomy is the treatment of choice 1
  • Requires preoperative alpha-blockade to prevent hypertensive crisis during surgery

2. Perioperative Management

• Preoperative preparation:

  • For cortisol-producing tumors: stress-dose steroids on induction (hydrocortisone 100 mg IV) 1
  • For pheochromocytomas: alpha-blockade followed by beta-blockade if needed

• Intraoperative management:

  • Hydrocortisone 100 mg IV on induction, followed by continuous infusion of hydrocortisone 200 mg/24 hours 1

• Postoperative management:

  • Continue hydrocortisone replacement until HPA axis recovery (may take 6-18 months)
  • Taper to maintenance doses based on clinical response

3. Long-term Management After Adrenalectomy

• For patients with HPA axis suppression:

  • Hydrocortisone 15-25 mg daily in split doses (first dose upon waking, last dose at least 6 hours before bedtime) 1
  • Lowest dose compatible with health and well-being should be used 1
  • Provide education on stress dosing and medical alert identification 1

• For patients with aldosterone deficiency:

  • Fludrocortisone 50-200 μg as a single daily dose 1, 2
  • Advise patients to consume salt and salty foods freely 1

Special Considerations

1. Adrenal crisis management:

   • Treat immediately with IV or IM hydrocortisone 100 mg followed by 100 mg every 6-8 hours until recovered 1
   • Administer isotonic (0.9%) sodium chloride solution at an initial rate of 1 L/hour until hemodynamic improvement 1
   • Identify and treat the underlying precipitant 1

2. Follow-up:

   • Annual review with assessment of health and well-being
   • Monitor weight, blood pressure, and serum electrolytes 1
   • Bone mineral density assessment every 3-5 years 1

3. Surgical approach considerations:

   • For tumors <4 cm with benign features: laparoscopic adrenalectomy
   • For tumors >6 cm or with aggressive features: open adrenalectomy may be preferred 1

Pitfalls and Caveats

1. Never delay treatment of suspected acute adrenal insufficiency for diagnostic procedures 1

2. Always start corticosteroids first when planning hormone replacement therapy for multiple deficiencies 1

3. Beware of adrenal crisis triggers:

   • Infection
   • Surgery
   • Trauma
   • Emotional stress

4. Educate patients about:

   • Stress dosing during illness
   • Medical alert identification
   • Self-injection of parenteral hydrocortisone 1

5. Avoid abrupt discontinuation of glucocorticoid therapy, which can precipitate adrenal crisis

By following this structured approach to the treatment of unilateral adrenal insufficiency, clinicians can optimize outcomes while minimizing morbidity and mortality associated with this condition.