Introduction
Acute adrenal insufficiency is rare and the more common presentation is one of insidious onset in otherwise well individuals. 80% of Addison’s disease is idiopathic or autoimmune (Grave’s disease or Hashimotos’s thyroiditis). It can be associated with Type 1 DM, pernicious anaemia, hypoparathyroidism, vitiligo or ovarian failure.
Causes
The main causes are either withdrawal or exogenous steroid therapy or intercurrent injury or stress resulting in increased steroid requirement. Including:
-
- Infection
- Trauma
- MI/CVA
- Asthma
- Hypotension
- ETOH
- Surgery
Presentation
-
- Hypotension and cardiovascular collapse
- Postural hypotension
- Anorexia, nausea, vomiting + abdo pain
- Hyponatraemia
- Dehydration
- Diarrhoea
- Symptoms of a precipitant
- Weight loss, fatigue, myalgia
- Hyperpigmentation
- Depression, apathy, confusion
- Hyperthyroidism
Investigation
-
- U&Es (Hyponatraemia and hyperkalaemia)
- FBC
- Glucose
- Calcium
- Serum cortisol
- ABG (metabolic acidosis)
- Urine (analysis and culture)
- CXR
- AXR
- Short Synacthen test
Try to do this at 9am but only if the patient is not too unwell
Venous blood sample for baseline cortisol and ACTH Basal cortisol >450nmol/l shows intact hypothalamic-pituitary-adrenal (HPA) axis.
-
- Give 250μg IV Synacthen
- Recheck cortisol at 30 minutes
- A normal response is basal cortisol in reference range, 30 minute rise of >170nmol/l, Peak >530nmol/l.
Treatment
-
- ABCDE
- Appropriate monitoring including ECG, CVP and fluid balance
- Treat shock
- IV fluids
- Treat hypoglycaemia
- Initial steroid therapy
- Dexamethasone 8mg IV or Hydrocortisone 50mg TDS
- Will not interfere with short Synacthen test, if not done
- Continued steroid therapy
- Hydrocortisone 200mg IV stat
- Then 100mg TDS
- Change to oral therapy after 72 hours
- Aim for a maintenance of 10mg BD
- Add in Fludrocortisone 100μg OD when stabilised on oral hydrocortisone if postural drop present or hyponatraemic
Prevention
-
- Patients on long term steroids should increase their steroid intake for predictable stressors.
- Vomiting requires IV/IM therapy
- STEROID CARD or MEDIC ALERT bracelet
