How should I diagnose an adrenal crisis in a patient with a known suprasellar tumor causing secondary adrenal insufficiency?

Diagnosing Adrenal Crisis in a Patient with a Suprasellar Mass

In a patient with a suprasellar tumor causing secondary adrenal insufficiency, diagnose adrenal crisis clinically and treat immediately without waiting for laboratory confirmation—draw blood for cortisol and ACTH before giving hydrocortisone 100 mg IV, but never delay treatment for test results. 1, 2

Immediate Clinical Recognition and Emergency Action

Recognize the clinical presentation immediately: hypotension (often <90/60 mmHg), severe dehydration, nausea/vomiting, abdominal pain, altered mental status (confusion, obtundation, or coma), and muscle pain or cramps. 1, 2 In secondary adrenal insufficiency from a suprasellar mass, you will not see hyperpigmentation because ACTH levels are low, unlike primary adrenal insufficiency. 3, 2

Treatment must never be delayed for diagnostic procedures when adrenal crisis is suspected—mortality increases with delayed intervention. 4, 1

First-Hour Emergency Protocol

• Administer hydrocortisone 100 mg IV bolus immediately upon clinical suspicion. This dose provides both glucocorticoid and mineralocorticoid activity by saturating 11β-hydroxysteroid dehydrogenase type 2. 1, 2

• Begin 0.9% isotonic saline infusion at 1 L over the first hour. Rapid volume expansion addresses the profound volume depletion characteristic of adrenal crisis. 1, 2

• Draw blood for serum cortisol, ACTH, electrolytes (sodium, potassium), creatinine, BUN, and glucose before administering hydrocortisone if feasible, but do not wait for results. 1, 2 If IV access cannot be rapidly established, give hydrocortisone 100 mg IM as a backup. 1

Laboratory Findings in Secondary Adrenal Insufficiency

Key distinction: In secondary adrenal insufficiency from a suprasellar mass, you will find low cortisol with low or inappropriately normal ACTH, unlike primary adrenal insufficiency where ACTH is markedly elevated. 4, 3, 5

Expected Laboratory Abnormalities

• Hyponatremia is present in approximately 90% of cases, though levels may be only marginally reduced. 1, 3, 2 Both secondary adrenal insufficiency and SIADH can present with euvolemic hypo-osmolar hyponatremia, making differentiation challenging. 3

• Hyperkalemia is typically absent in secondary adrenal insufficiency because the renin-angiotensin-aldosterone system remains intact (mineralocorticoid production is preserved). 4, 3 Hyperkalemia occurs in only ~50% of primary adrenal insufficiency cases. 1, 2

• Elevated creatinine and BUN due to prerenal renal failure from volume depletion. 1, 2

• Hypoglycemia is more common in children but can occur in adults. 1, 2

Diagnostic Cortisol and ACTH Interpretation

• Basal cortisol <250 nmol/L (<9 μg/dL) with low or inappropriately normal ACTH in acute illness strongly suggests secondary adrenal insufficiency. 3, 2, 5

• Morning cortisol 140-275 nmol/L (5-10 μg/dL) with low or inappropriately normal ACTH is indicative of secondary adrenal insufficiency. 3

• If cortisol levels are indeterminate (5-18 μg/dL), perform ACTH stimulation testing after stabilization to definitively confirm or exclude adrenal insufficiency. 3

Ongoing Management (First 24-48 Hours)

• Continue hydrocortisone 200 mg per 24 hours as continuous IV infusion (preferred) or alternatively 50 mg IV/IM every 6 hours. 1, 2

• Provide a total of 3-4 L of 0.9% saline over 24-48 hours, with frequent monitoring of hemodynamics and serum electrolytes to avoid fluid overload. 1, 2

• Admit patients with persistent hypotension to an ICU or high-dependency unit. 1

• Implement gastric stress-ulcer prophylaxis and low-dose heparin for DVT prophylaxis. 1

• Treat identified infections promptly with appropriate antimicrobial agents, as infections are the most common precipitant of adrenal crisis. 1, 2

• Perform frequent blood glucose monitoring, particularly in children who are more vulnerable to hypoglycemia. 1

Critical Pitfalls to Avoid

• Never delay glucocorticoid therapy for diagnostic confirmation—mortality rises with treatment postponement. 4, 1

• Do not rely on the absence of hyperkalemia to exclude adrenal crisis in secondary adrenal insufficiency, as mineralocorticoid function is preserved. 4, 3

• Do not add separate mineralocorticoid (fludrocortisone) during acute crisis management in secondary adrenal insufficiency—it is not needed because aldosterone production is intact, and high-dose hydrocortisone provides adequate mineralocorticoid activity during the acute phase. 4, 1

• Do not start thyroid hormone replacement before adequate glucocorticoid replacement in patients with multiple pituitary hormone deficiencies from the suprasellar mass, as this can trigger adrenal crisis. 4, 1

Transition to Maintenance Therapy

• Taper parenteral glucocorticoids over 1-3 days and switch to oral therapy once the precipitating illness permits oral intake. 1

• Standard maintenance dosing for secondary adrenal insufficiency is hydrocortisone 15-25 mg daily in divided doses (typically 10 mg at 7:00 AM, 5 mg at 12:00 PM, and 2.5-5 mg at 4:00 PM) or prednisone 3-5 mg daily. 1, 3, 5

• Do not add fludrocortisone for maintenance therapy in secondary adrenal insufficiency, as mineralocorticoid production is preserved. 4, 3

Etiologic Workup After Stabilization

• Obtain MRI of the pituitary/hypothalamus to characterize the suprasellar mass and assess for other pituitary hormone deficiencies (TSH, LH/FSH, GH, prolactin). 6, 7

• Evaluate for pituitary apoplexy if the patient presents with sudden onset of symptoms, visual field defects (bitemporal hemianopia), or cranial nerve palsies (especially 6th nerve palsy), as hemorrhagic or ischemic necrosis of a pituitary adenoma can precipitate acute adrenal crisis. 7

• Screen for other pituitary hormone deficiencies that commonly accompany secondary adrenal insufficiency from suprasellar masses, including hypothyroidism, hypogonadism, and growth hormone deficiency. 6

Patient Education and Long-Term Management

• Provide emergency injectable hydrocortisone 100 mg IM kit with self-injection training for use during future acute illnesses. 1, 5

• Instruct patients to double or triple oral glucocorticoid doses during illness, fever, or physical stress. 1, 5

• Ensure patients wear medical alert identification jewelry indicating adrenal insufficiency to trigger stress-dose corticosteroids by emergency personnel. 1, 5

• Arrange endocrinology consultation for ongoing management, stress-dosing education, and coordination with neurosurgery if the suprasellar mass requires surgical intervention. 4, 1