Adrenal Disease - Hypoadrenalism

Question 1

What is Hypoadrenalism?

Answer 1

Adrenal Insufficiency - the adrenal glands do not produce enough steroid hormones, especially Cortisol and Aldosterone.

Question 2

Aetiology of Primary Adrenal Insufficiency.

Answer 2

Addison’s Disease - autoimmune damage of the adrenal glands, resulting in a reduction in secretion of Cortisol and Aldosterone.

Question 3

Aetiology of Secondary Adrenal Insufficiency.

Answer 3

Inadequate ACTH stimulates the adrenal glands, resulting in low Cortisol release - damage or loss of pituitary gland (surgery, infection, loss of blood flow, radiotherapy).

Question 4

What is Sheehan’s Syndrome?

Answer 4

Massive blood loss during childbirth leads to pituitary gland necrosis.

Question 5

What is Tertiary Adrenal Insufficiency?

Answer 5

Inadequate CRH release by the hypothalamus, resulting in low Cortisol release.

Question 6

What is the main cause of Tertiary Adrenal Insufficiency (3)?

Answer 6

1. Long-Term (3+ weeks) oral steroids causes suppression of the hypothalamus.
2. When the exogenous steroids are suddenly withdrawn the hypothalamus does not ‘wake up’ fast enough and endogenous steroids are not adequately produced.
3. Long-term steroids are tapered slowly to allow time for the adrenal axis to regain normal function.

Question 7

Clinical Presentation of Adrenal Insufficiency (6).

Answer 7

1. Fatigue.
2. Nausea.
3. Cramps.
4. Abdominal Pain.
5. Reduced Libido.
6. Salt-Craving.

Question 8

Clinical Signs in Adrenal Insufficiency (5).

Answer 8

1. Bronze Hyperpigmentation to Skin (ACTH Stimulates Melanocyte Production of Melanin) - Palmar Creases.
2. Hypotension - Postural Hypotension.
3. Hypoglycaemia.
4. Vitiligo.
5. Loss of Pubic Hair in Women.

Question 9

Bloods in Adrenal Insufficiency (5).

Answer 9

1. Hyponatraemia.
2. Hyperkalaemia (not necessary).
3. Adrenal Autoantibodies - Adrenal Cortex Antibodies, 21-Hydroxylase Antibodies.
4. Metabolic Acidosis.
5. Hypoglycaemia.

Question 10

Endocrine Tests in Adrenal Insufficiency (3).

Answer 10

1. Test of Choice : Short Synacthen Test.
2. Early Morning Cortisol (8-9AM).
3. ACTH Levels (replaced Long Synacthen Test).

Question 11

Imaging in Adrenal Insufficiency (2).

Answer 11

1. CT/MR Adrenals - Adrenal Tumour, Haemorrhage, Structural Pathology.
2. MRI Pituitary - Pituitary Pathology.

Question 12

ACTH Levels in Adrenal Insufficiency (2).

Answer 12

1. Primary : HIGH ACTH - Pituitary tries very hard without any negative feedback.
2. Secondary : LOW ACTH - no stimulation by ACTH.

Question 13

Method of Short Synacthen Test (3).

Answer 13

1. Administer Synacthen (Synthetic ACTH).
2. Measure blood Cortisol at baseline, 30 and 60 minutes after administration.
3. Ideally in Morning (Freshest).

Question 14

Results of Short Synacthen Test.

Answer 14

1. Healthy : Synacthen stimulates healthy adrenal glands so Cortisol level will double at least.
2. Primary Adrenal Insufficiency : Failure of Cortisol to rise less than 2x the baseline.

Question 15

Management of Adrenal Insufficiency.

Answer 15

Replacement Steroids titrated to signs, symptoms and electrolytes and double dose of Hydrocortisone (not for Fludrocortisone) during acute illness (DON’T STOP).

Question 16

Replacement Steroids used in Adrenal Insufficiency (2).

Answer 16

1. Hydrocortisone - Glucocorticoid (CORTISOL) in 2/3 doses - majority in first half of day (20-30mg per day).
2. Fludrocortisone - Mineralocorticoid (ALDOSTERONE).

Question 17

Other Primary Causes of Hypoadrenalism (5).

Answer 17

1. TB.
2. Metastases (Bronchial Carcinoma).
3. Meningococcal Septicaemia (Waterhouse-Friderichsen Syndrome).
4. HIV.
5. Antiphopsholipid Syndrome.

Question 18

What is performed if the Short Synacthen Test is not readily available (3)?

Answer 18

9AM Serum Cortisol -

1. > 500 nmol/L - Addison’s very unlikely.
2. <100nmol/L - abnormal.
3. 100-500 nmol/L - prompt a Short ACTH Test.