Adrenal Insufficiency Flashcards
Define adrenal insufficiency
Deficiency of adrenal cortical hormones (e.g. mineralcorticoids, glucocorticoids and androgens)
Explain the aetiology of adrenal insufficiency
Primary Adrenal insufficiency: Addison’s disease
- >70% autoimmune
- Infections: e.g. TB, Meningococcal septicaemia (Waterhouse-Friderichsen Syndrome), CMV, Histoplasmosis
- Infiltration: metastasis (mainly lung, breast and melanoma), Lymphomas, Amyloidosis
- Inherited: Adrenoleukodystrophy, ACTH receptor mutation
- Surgical: after bilateral adrenalectomy
Secondary adrenal insufficiency: pituitary or hypothalamic disease
- Infarction: Secondary to Thrombophilia e.g Sheehan’s Syndrome
- Pituitary Adenoma
- Iatrogenic: Sudden cessation of long-term steroid therapy
Summarise the epidemiology of adrenal insufficiency
- Most common cause is Iatrogenic
- Primary causes are rare
Recognise the presenting symptoms of adrenal insufficiency
Acute Presentation (Addisons Crisis):
- Acute adrenal insufficiency
- Major haemodynamic collapse
- Precipitated by stress (e.g. infection, surgery)
Chronic Presentation: symptoms usually vague + non-specific
- Dizziness
- Anorexia
- Weight loss
- Diarrhoea and Vomiting
- Abdominal pain
- Lethargy
- Weakness
- Depression
Recognise the signs of adrenal insufficiency on physical examination
- Postural Hypotension
- Increased Pigmentation (most noticable on buccal mucosa, scares, skin creases, nails and pressure points)
- Loss of body hair in women (due to androgen deficiency)
- Associated autoimmune condition (e.g. vitiligo)
- Addisonian Crisis Signs: hypotensive shock, tachycardia, pale, clammy, cold, oliguria
List the types of Investigations required
- Confirm diagnosis
- Identify level of the defect in the HPA-axis
- Identify the cause
- Check TFTs
- Addisonian Crisis investigations
Identify appropriate investigations for adrenal insufficiency to confirm the diagnosis
- 9am Serum Cortisol (<100nmol/L is diagnostic, >550ml makes it unlikely)
- Short SynACTHen test: IM 250 µg tetrocosactrin (synthetic ACTH). If serum Cortisol <550nmol/L at 30 mins = adrenal failure
Identify appropriate investigations for adrenal insufficiency to identify the level of the defect in the HPA-axis
- ACTH is high in primary disease and low in secondary
- Long SynACTHen test:
1mg synthetic ACTH administered, measure serum cortisol at 0,30,60,90 and 120 mins. Measure again at 4, 6, 8, 12 and 24 hrs. Patients with primary adrenal insufficiency show no increase after 6hrs
Identify appropriate investigations for adrenal insufficiency to identify the cause
- Autoantibodies (against 21-hydroxylase)
- Abdominal CT or MRI
- Other tests (adrenal biopsy, culture, PCR)
Identify appropriate investigations in an Addisonian Crisis
- FBC (neutrophilia = infection)
- U&Es: high urea, low sodium and high potassium
- CRP/ESR
- Calcium (may be raised)
- Glucose (low)
- Blood cultures and sensitivity
- Urinalysis
Generate a management plan for adrenal insufficiency
Addisonian Crisis:
- Rapid IV fluid rehydration
- 50ml of 50% dextrose to correct hypoglycaemia
- IV 200mg hydrocortisone bolus
- Followed by 100mg 6 hourly hydrocortison til BP is stable
- Treat precipitating cause (e.g. antibiotics for infection)
- Monitor
Chronic:
- Replacement of
- glucocorticoids with hydrocortisone (3/day)
- mineralocorticoids with fludrocortisone - Hydrocortisone needs to be increased in times of acute illness or stress e.g. infection
- Note: if pt has hypothyroidism, give hydrocortisone before thyroxine (to prevent precipitating an Addisonian crisis)
- Advice: have steroid warning card, medic-alert bracelet and emergency hydrocortison to hand
Identify the possible complications of adrenal insufficiency and its management
- Hyperkalaemia: will be reversed with glucocorticoid and mineralocorticoid replacement
- Death during addisonian crisis: manage quickly and correctly
Summarise the prognosis for patients with adrenal insufficiency
- Adrenal function rarely recovers
- Normal life expectancy if treated
