Addisons disease

Question 1

Definition

Answer 1

Primary adrenal insufficiency
Adrenal glands can’t make enough mineralocorticoids
Therefore, kidney’s can’t retain sodium
Sodium and water is lost which results in a decreased ECF volume

Question 2

Causes

Answer 2

Infections: TB, fungal
Autoimmune complete destruction of adrenal cortex
Metastatic malignancy

Question 3

Clinical features

Answer 3

Gradual onset of symptoms 
Dehydration
Malaise
Tiredness
Poor appetite
Weight loss 
Buccal pigmentation 
Skin pigmentation - mouth, hand creases 
Craving for salty foods 
Amenorrhoea 
THEN
becomes acutely unwell with abdominal pain, vomiting, diarrhoea

Question 4

Examination findings

Answer 4

Postural hypotension

Question 5

Investigations

Answer 5

Hyponeutraemia (decreased Na, increased K)
Hypoglycaemia
Decreased aldosterone
Increased renin levels - to try and increase BP
Increased ACTH
Synacthen test needed

Question 6

Example of mineralocorticoid involved in addison’s disease

Answer 6

Aldosterone

Question 7

What is a synacthen test?

Answer 7

Stimulation test
Measure plasma cortisol levels at time 0
Measure plasma cortisol levels 30 mins after synthetic ACTH injection

• if patient doesn’t stimulate over 450nmol/L of cortisol then they have adrenal insuddiciency

Question 8

Which patients do you not carry out a synacthen test on?

Answer 8

Asthmatics

Question 9

Management

Answer 9

Hydrocortisone (cortisol replacement)

Fludrocortisone (aldosterone replacement)

Question 10

Addisonian crisis - definition

Answer 10

Acute adrenal failure

Question 11

Addisonian crisis - clinical features

Answer 11

Addisons disease features + 
Hypotension
Lower back pain
Severe vomiting and diarrhoea 
Loss of consciousness

Question 12

Addisonian crisis - management

Answer 12

IV hydrocortisone 50-100mg
IV saline
IV glucose
IV sliding scale insulin