Adrenal insufficiency Flashcards
What is adrenal insufficiency?
Adrenal insufficiency occurs when the adrenal glands do not produce enough steroid hormones, particularly cortisol and aldosterone, and can be life-threatening unless hormones are replaced.
What is Addison’s disease?
Addison’s disease is a type of primary adrenal insufficiency caused by damage to the adrenal glands, leading to reduced cortisol and aldosterone secretion, most commonly due to autoimmune causes.
What is secondary adrenal insufficiency?
Secondary adrenal insufficiency is caused by inadequate adrenocorticotropic hormone (ACTH) and lack of stimulation of the adrenal glands, often due to damage to the pituitary gland.
What causes secondary adrenal insufficiency?
Causes include:
* Tumors (e.g., pituitary adenomas)
* Surgery or radiotherapy to the pituitary
* Sheehan’s syndrome (postpartum hemorrhage causing pituitary damage)
* Trauma
What is tertiary adrenal insufficiency?
Tertiary adrenal insufficiency occurs due to inadequate corticotropin-releasing hormone (CRH) from the hypothalamus, often due to prolonged use of oral steroids.
What are the symptoms of adrenal insufficiency?
Symptoms include:
* Fatigue
* Muscle weakness and cramps
* Dizziness and fainting
* Thirst and salt craving
* Weight loss
* Abdominal pain
* Depression
* Reduced libido
What are the signs of adrenal insufficiency?
Signs include:
* Bronze hyperpigmentation of the skin, especially in skin creases, scars, lips, and mucosa.
* Hypotension, particularly postural hypotension (drop in blood pressure on standing).
What causes the bronze hyperpigmentation in adrenal insufficiency?
It is caused by excessive ACTH, which stimulates melanocytes to produce melanin.
What should you check in a patient with suspected adrenal insufficiency?
Check for a medical alert bracelet, as steroid-dependent patients may need emergency care if unconscious.
What are the biochemical findings in adrenal insufficiency?
Common findings include:
* Hyponatraemia (low sodium)
* Hyperkalaemia (high potassium)
* Hypoglycaemia (low glucose)
* Raised creatinine and urea (due to dehydration)
* Hypercalcaemia (high calcium)
What is the role of the short Synacthen test in diagnosing adrenal insufficiency?
The short Synacthen test (ACTH stimulation test) is used to diagnose adrenal insufficiency. Synthetic ACTH is given, and cortisol levels are measured. Failure to double cortisol levels suggests adrenal insufficiency.
What does the short Synacthen test reveal in primary and secondary adrenal insufficiency?
Primary adrenal insufficiency (Addison’s disease): Failure of cortisol to rise after ACTH administration.
Secondary adrenal insufficiency: Also results in failure to rise but usually with lower ACTH levels.
What is the management of adrenal insufficiency?
Management involves steroid replacement:
* Hydrocortisone for cortisol replacement.
* Fludrocortisone for aldosterone replacement, if needed.
What additional care is provided for adrenal insufficiency patients?
Patients are given a steroid card, ID tag, and emergency letter. They are taught to administer intramuscular hydrocortisone in emergencies.
What is adrenal crisis (Addisonian crisis)?
Adrenal crisis is a life-threatening acute form of adrenal insufficiency that presents with:
* Reduced consciousness
* Hypotension
* Hypoglycaemia
* Hyponatraemia and hyperkalaemia
How is adrenal crisis managed?
Management includes:
* ABCDE approach
* Intramuscular or intravenous hydrocortisone (initial dose 100mg)
* Intravenous fluids
* Correcting hypoglycaemia (e.g., IV dextrose)
* Monitoring electrolytes and fluid balance
