Key Facts

Adrenal crisis is a medical emergency requiring immediate hydrocortisone. The most common scenario is a patient with known adrenal insufficiency who becomes unwell and does not increase their steroid dose. Prevention through sick-day rule education is critical.

Epidemiology

~5-10 episodes per 100 patient-years in patients with known adrenal insufficiency. Mortality per crisis ~6%. Higher risk: primary adrenal insufficiency (Addison), concomitant diabetes, elderly.

Aetiology

Acute cortisol deficiency in the context of physiological stress. Causes: non-adherence to sick-day rules (commonest), abrupt corticosteroid withdrawal after prolonged use (>3 weeks of prednisolone ≥7.5mg/day), bilateral adrenal haemorrhage/infarction, pituitary apoplexy, first presentation of undiagnosed Addison disease.

Pathophysiology

Cortisol is essential for vascular tone, cardiovascular function, and glucose homeostasis. In cortisol deficiency: loss of vascular tone → refractory hypotension; impaired gluconeogenesis → hypoglycaemia; renal sodium wasting → hyponatraemia and dehydration; impaired stress response → cardiovascular collapse.

Symptoms

• Severe weakness, fatigue
• Nausea, vomiting, abdominal pain (may mimic acute abdomen)
• Confusion, drowsiness → coma
• Muscle cramps

Signs

• Profound hypotension/shock: refractory to IV fluids and vasopressors without steroids
• Tachycardia
• Dehydration
• Hypothermia (or fever if infection precipitant)
• Hyperpigmentation (if chronic Addison)

Biochemistry

• Hyponatraemia, hyperkalaemia (primary AI)
• Hypoglycaemia
• Raised urea (dehydration)
• Hypercalcaemia (sometimes)

Red Flags

• Hypotension not responding to fluids/vasopressors → ALWAYS consider adrenal crisis
• Patient wearing MedicAlert bracelet with reduced consciousness
• Collapse in patient on long-term steroids who has recently stopped

Immediate (Before Giving Steroids if Possible)

• Random cortisol: <100 nmol/L during acute illness virtually diagnostic; <250 nmol/L highly suggestive
• ACTH: high = primary; low = secondary (send simultaneously)
• U&Es: Na⁺, K⁺, renal function
• Blood glucose
• Blood gas: metabolic acidosis
• FBC, CRP, blood cultures, lactate: identify infection
• ECG: hyperkalaemia changes

Do NOT delay treatment for investigation results

Emergency Treatment

1. IV/IM hydrocortisone 100mg STAT (IM if no IV access — ambulance crews can give this)
2. IV 0.9% NaCl: rapid fluid resuscitation (1L stat then guided by response)
3. Continuous IV hydrocortisone: 50mg QDS IV or 200mg/24h continuous infusion
4. IV dextrose if hypoglycaemic
5. Treat precipitant: antibiotics if infection; DO NOT wait for culture results
6. Monitor: continuous cardiac monitoring (hyperkalaemia risk), hourly BP, glucose, fluid balance

Subsequent Management

• Once stable and eating: convert to oral hydrocortisone (double usual dose initially, then taper to maintenance over 2-3 days)
• Add fludrocortisone when IV hydrocortisone dose <50mg/day (high-dose hydrocortisone has sufficient mineralocorticoid activity)
• Investigate cause if new presentation

Prevention (Critical)

• Sick-day rules education: double dose for illness; IM injection if vomiting
• Steroid emergency card + MedicAlert
• Emergency IM hydrocortisone kit: train patient and family
• Gradual steroid withdrawal: in patients on long-term exogenous steroids (>3 weeks at ≥7.5mg prednisolone)

With prompt treatment, recovery from adrenal crisis is usually rapid (hours to days). Mortality ~6% per crisis episode. Recurrence common: ~50% of patients with adrenal insufficiency experience at least one crisis. Most crises are preventable with adequate sick-day rule education and emergency preparedness. Delayed treatment significantly worsens outcome.

Adrenal Crisis — Key Steps

Steroid Withdrawal Risk