ACUTE ADRENAL INSUFFICIENCY

Most common cause is secondary adrenal failure (hypothalamic-pituitary disease with inadequate ACTH or long-term corticosteroid therapy), where mineralocorticoid production is generally preserved

Symptoms and signs

• Lethargy
• Nausea
• Weight loss
• Hypoglycaemia

Indicators of severe adrenal insufficiency

• Hyponatraemia
• Hypoglycaemia
• Hypotension – systolic BP <90 mmHg, diastolic BP <50 mmHg
• Tachycardia – with no obvious cause

Primary adrenal failure

• Hypotension (postural/sustained)
• Pigmentation (palmar/buccal/scars/pressure areas)
• Vitiligo

Secondary adrenal failure

• Pallor
• Loss of pubic/axillary hair (because of co-existing secondary hypogonadism)

Risk factors

Primary adrenal failure

• Auto-immune disease (diabetes/hypothyroidism/pernicious anaemia)
• TB
• Metastases, especially from carcinoma of lung

Secondary adrenal failure

• Withdrawal of oral (or potent topical or inhaled) corticosteroids
• Pituitary surgery/radiotherapy

• FBC
• U&E
• Blood glucose

Check for severe adrenal insufficiency

Adrenal failure suspected

• Send gold top blood bottles for markers of pituitary function:
• Cortisol
• FSH/LH
• testosterone (males)
• TSH/FT4
• growth hormone (GH)
• insulin-like growth factor 1 (IGF-1)
• prolactin
• If adrenal insufficiency strongly suspected, send EDTA (purple) top blood bottle for adrenocorticotropic hormone (ACTH)

Results in primary adrenal failure only

• Hyperkalaemia
• Raised urea

• If severely ill:
• hydrocortisone 100 mg as slow IV bolus, followed by 100 mg by slow IV bolus 6-hrly
• sodium chloride 0.9% 1 L by IV infusion over 30–60 min, followed by 3–4 L IV over next 24 hr
• If hypoglycaemic, give simultaneous infusion of:
• glucose 20% 100 mL by IV infusion over 30 min, followed by glucose 10% 1 L by IV infusion over 12 hr. Monitor blood glucose and change to glucose 20% if 10% inadequate
• glucagon is unhelpful in this situation

• Admit to endocrinology ward
• When improving and tolerating oral fluid:
• hydrocortisone 20 mg oral 8-hrly
• refer to endocrinology team for advice on maintenance dosage (usually 20 mg in morning and 10 mg in afternoon – no later than 1800 hr)
• if diagnosis in doubt, seek advice from endocrinology team about substituting dexamethasone 1 mg oral 8-hrly for hydrocortisone and perform SST within three days. If on oral hydrocortisone (maintenance dose 20 mg in morning and 10 mg in afternoon), afternoon dose can be omitted and SST carried out between 0800–0900 next day
• after the test and while awaiting result, revert to maintenance dose
• In primary adrenal failure:
• add fludrocortisone 50–100 microgram oral daily
• request adrenal autoantibodies
• arrange chest and abdominal X-rays
• if TB suspected, request CT scan of adrenals
• If secondary adrenal failure suspected, refer to endocrinology team

• U&E daily
• Lying and standing BP twice daily, looking for orthostatic hypotension

• Patients must carry ‘Steroid card’ and wear ‘Medic Alert bracelet’
• Patients must understand need for:
• lifelong hydrocortisone
• doubling the daily dose for the duration of any intercurrent illness
• parenteral hydrocortisone if vomiting (supply with ampoule of hydrocortisone 100 mg to keep in fridge for use by paramedics in emergency)
• Refer to endocrinology for follow-up