Background
- Classified on problem site: hypothalamic-pituitary-adrenal axis
- Normal adrenal=
- Mineralocorticoids - zona glomerulosa
- Gluccortisoids - zona fasciculata
- Sex hormones - zona reticularis
- Secondary = pit. cannot produce enough ACTH or adrenals not responding to ACTH
- Tertiary = little/ineffective CRH from hypothalamus
Aetiology
Hypo-cortisol caused by:
- Long-term steroid treatment
- Adrenocortical disease (Addison's disease), autoimmune, infections (tuberculosis, HIV), haemorrhage, metastatic deposits
- Pituitary or hypothalamic disease (tumour, trauma, infection, or ischaemia)
For primary:
- 90% autoimmune
- F > M, 30-50 yo
Clinical
- Insidious: Wt loss, fatigue ± ↓BP (NB postural)
- Occasionally skin pigmentation (MSH)
- If pituitary- no skin pigmentation or hypokalaemia (mineralocorticoids okay)
- Diagnosed with low Serum/plasma cortisol (particularly early morning)
- May have transient hypocortisolism (< 400nmol/l) in sepsis
- Confirm with a short ACTH test
- Beware those on chronic steroid therapy unless morning cortisol > 200 nmol/l
Labs
- Hyponatraemia early
- In ↓ACTH, K+ may be normal
- Later hyperkalaemia
- Hypercalcaemia
- Hypoglycaemia
- Anaemia of chronic disease
Addisonian crisis
- Altered consciousness, ↓BP, ↓Glucose
- Usually a Hx of recent nausea, vomiting
- Beware and treat for underlying trigger (sepsis, trauma, SCS)
- Baseline bloods and save serum before treatment for later cortisol level measurement
- ± CXR then:
- Hydrocortisone 200mg IV
- Correct dehydration, hyponatraemia and hypoglycaemia:
- 2 litres saline in first 3 hours
- Closely monitor glucose if unresponsive or intubated
Links
- Bornstein SR, Allolio B, Arlt W, et al: Diagnosis and treatment of primary adrenal insufficiency: an Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab 101: 364, 2016
- https://emcrit.org/ibcc/adrenal-crisis/ (August 2021)
- Tintinalli (7th edition) 2011: p1453-1456
- Emergency Medicine MCQs Waruna de Alwis