Adrenal insufficiency Flashcards
Define adrenal insufficiency
Deficiency of adrenal cortical hormones (e.g. mineralocorticoids, glucocorticoids and androgens)
Explain the aetiology/risk factors of adrenal insufficiency
Primary Adrenal Insufficiency
Addison’s disease (usually autoimmune)
Secondary Adrenal Insufficiency
Pituitary or hypothalamic disease
Infections - Tuberculosis, Meningococcal septicaemia (Waterhouse-Friderichsen Syndrome), CMV, Histoplasmosis
Infiltration - Metastasis (mainly from lung, breast, melanoma), Lymphomas, Amyloidosis
Infarction
Secondary to thrombophilia
Inherited
Adrenoleukodystrophy
ACTH receptor mutation
Surgical
After bilateral adrenalectomy
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
Chronic Presentation - the symptoms tend to be VAGUE and NON-SPECIFIC Dizziness Anorexia Weight loss Diarrhoea and Vomiting Abdominal pain Lethargy Weakness Depression
Acute Presentation (Addisonian Crisis)
Acute adrenal insufficiency
Major haemodynamic collapse
Precipitated by stress (e.g. infection, surgery)
Recognise the signs of adrenal insufficiency on physical examination
Postural hypotension
Increased pigmentation - More noticeable on buccal mucosa, scars, 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 Cold Clammy Oliguria
Identify appropriate investigations for adrenal insufficiency
To confirm the diagnosis - 9 am Serum Cortisol
(< 100 nmol/L is diagnostic of adrenal insufficiency)
> 550 nmol/L makes adrenal insufficiency unlikely
Short Synacthen Test - IM 250μg tetrocosactrin (synthetic ACTH) - > Serum cortisol < 550 nmol/L at 30 mins indicates adrenal failure
Identify the level of the defect in the hypothalamo-pituitary-adrenal axis (HIGH in primary disease, LOW in secondary)
Long Synacthen Test - 1 mg synthetic ACTH administered. Measure serum cortisol at 0, 30, 60, 90 and 120 minutes. Then measure again at 4, 6, 8, 12 and 24 hours. Patients with primary adrenal insufficiency show no increased after 6 hour.
Identify the cause Autoantibodies (against 21-hydroxylase) Abdominal CT or MRI Other tests (adrenal biopsy, culture, PCR) Check TFTs
Investigations in Addisonian crisis?
FBC (neutrophilia --> infection) U&Es - High urea, Low sodium, High potassium CRP/ESR Calcium (may be raised) Glucose - low
Blood cultures
Urinalysis
Culture and sensitivity
Generate a management plan for adrenal insufficiency
Replacement of:
Glucocorticoids with hydrocortisone (3/day)
Mineralocorticoids with fludrocortisone
Hydrocortisone dosage needs to be increased during times of acute illness or stress
NOTE: if the patient also has hypothyroidism, give hydrocortisone BEFORE thyroxine (to prevent precipitating an Addisonian crisis)
Advice
Have a steroid warning card
Wear a medic-alert bracelet
Emergency hydrocortisone on hand
Generate a management plan for Addisonian Crisis
Rapid IV fluid rehydration
50 mL of 50% dextrose to correct hypoglycaemia
IV 200 mg hydrocortisone bolus
Followed by 100 mg 6 hourly hydrocortisone until BP is stable
Treat precipitating cause (e.g. antibiotics for infection)
Monitor
Identify the possible complications of adrenal insufficiency
HYPERKALAEMIA
Death during Addisonian crisis
Summarise the prognosis for patients with adrenal insufficiency
Adrenal function rarely recovers
Normal life expectancy if treated
Autoimmune Polyendocrine Syndrome Type 1 - autosomal recessive disorder caused by mutations in the AIRE gene. Consists of the following diseases: Addison's disease Chronic mucocutaneous candidiasis Hypoparathyroidism
Type 2 - also known as Schmidt's Syndrome Addison's disease Type 1 Diabetes Hypothyroidism Hypogonadism
