Addison’s Disease Flashcards
What is Addison’s Disease?
Adrenal insufficiency results in a lack of production of the adrenal hormones: aldosterone, cortisol and oestrogen/testosterone. However only primary disease has an effect on the mineralocorticoid (aldosterone) levels. Primary autoimmune adrenal insufficiency is called Addison’s disease.
Aldosterone - Controls sodium, potassium and fluid levels adjusting blood pressure.
Cortisol - Causes the production of glucose in the liver and increases metabolism of muscle and fat. Cortisol also helps the body regulate its response to stress. It decreases inflammation and decreases the immune system response.
Sex Steroids - Sexual Function
Patients can present with chronic symptoms or those of an adrenal crisis, precipitated by infection or stress etc.
What are the causes of Addison’s Disease?
Common – Addison’s Disease (Primary Autoimmune adrenal gland destruction), Low ACTH levels (Chronic Steroid use suppresses ACTH leading to adrenal cortex atrophy, stress or acute withdrawal can therefore cause an acute insufficiency as the adrenal gland cannot compensate), TB
Other – Infection (HIV, Fungal), Cancer (Lung, breast, kidney metastasise or lymphoma), Congenital adrenal hyperplasia, Iatrogenic, Haemorrhage (Adrenal insufficiency occurs days/weeks after a haemorrhage due to the stress response requiring much more cortisol), Pituitary/Hypothalamic Lesion
What will you find on history taking of Addison’s Disease?
Symptoms:
Chronic - Tiredness, Lethargy, Anorexia, Weight loss, Vomiting, Abdominal Pain, Postural Hypotension, Diarrhoea/Constipation, Hyperpigmentation (Of the buccal mucosa, palms of hands and in scars. This only occurs in primary disease as is caused by raised ACTH levels)
Acute Adrenal Crisis - Nausea and vomiting, Hypotension, Hyponatraemia, Hyperkalaemia, Fever
Risk Factors:
Personal or family history of any other autoimmune conditions (Pernicious anaemia, Hypothyroidism, Type 1 diabetes) – Predisposes to increased likelihood of autoimmune Graves’ disease
Middle Aged Females
Specific Questions to ask:
Recent withdrawal of steroid treatment?
If presenting acutely – Ask about precipitating causes e.g. Infection, MI, trauma
Differentials:
Hyperthyroidism
Anorexia
What will you find on examination of a patient with Addisons Disease?
Examination findings: End of the bed: Weight Loss Hand: Hyperpigmentation in palmar creases, knuckles, elbows, scars Hypotension and Postural Hypotension Chest: Loss of axillary and pubic hair in women Legs: Hyperpigmentation of knees
What investigations will you order in suspected Addisons Disease?
Bedside:
Capillary Glucose – Adrenal insufficiency can cause hypoglycaemia (Low cortisol levels)
ECG – If electrolyte disturbances to look for arrhythmias
Bloods:
U&E’s – Adrenal insufficiency causes Hyponatremia, Hyperkalaemia and sometimes Hypercalcaemia (due to reduced aldosterone levels). May also show dehydration (Raised urea and creatinine) due to lack of aldosterone. These changes will not occur in secondary adrenal insufficiency
FBC – Looking for any associated Pernicious (normocytic) Anaemia. May also show or lymphocytosis, eosinophilia. May show precipitating infection
LFT – Looking for an underlying liver cancer that could have metastasised. Some patients will show Raised Transaminase levels
ACTH Levels - Primary Insufficiency (ACTH high) Secondary insufficiency (ACTH low)
TFT’s – Raised TSH is associated with adrenal insufficiency
Prolactin levels -Hyperprolactinemia is associated with adrenal insufficiency
ABG – Patients are at risk of metabolic acidosis (Low Na levels reduce exchange of H+ and Na in the kidneys)
Adrenal Autoantibodies – Raised in Addison’s disease
Serum Cortisol – Only used in adrenal crisis where time is limited, >25 excludes an adrenal crisis but values lower than this are not diagnostic
Imaging:
CXR – Looking for an underlying lung cancer that could have metastasised to the adrenals, or any TB that may have spread
Abdominal X-ray – Looking for adrenal calcification which may indicate previous TB infection
CT/MRI of adrenal glands - if primary cause suspected and autoantibodies are negative, adrenals will be enlarged in Addison’s
CT/MRI of Pituitary/Hypothalamus- if secondary cause suspected
Special Tests:
Synachten test - Measure serum cortisol after giving Synachten (synthetic ACTH). Cortisol/Aldosterone needs to rise above the patient’s baseline and above a certain level to be diagnostic. This is diagnostic of secondary insufficiency.
Aldosterone Levels – Unchanged in secondary causes of adrenal insufficiency
Insulin Tolerance test (rarely done as can be unsafe)– Insulin infusion given to reduce blood glucose levels. Cortisol levels measured (Cortisol should rise to increase blood glucose levels but will not in adrenal insufficiency)
What is the treatment of Addison’s Disease?
Refer to endocrinologist
Lifestyle:
Educate the patient about the condition, specifically about the importance of not missing steroid or stopping abruptly and possible complications e.g. Adrenal crisis
Given steroid card and medical emergency bracelet
Frequent Hospital Monitoring: Weight monitoring, Blood Pressure, Electrolytes, FBC, Vitamin B12, Full history and examination to see if doses are correct
Annual review for other autoimmune conditions – TFT’s, HBA1c, FBC (pernicious anaemia), B12, Coeliac Screen
Emergency Hydrocortisone injection kit
Prescriptions are free
Medical:
Glucocorticoid/Cortisol replacement with Hydrocortisone
Mineralocorticoid /Aldosterone replacement with Fludrocortisone – Only required in primary adrenal insufficiency
Doses will need to be doubled if the patient is unwell/having surgery etc
What is the treatment of an Addisonian Crisis?
Resuscitation: Treat urgently, before blood returned
A-E approach
Get IV Access/Give O2 to maintain sats of 94+ /Attach 12 lead ECG
Patients are often hypotensive so will require fluids
Assessment with AMPLE history and brief examination
Get help - Medical reg on call, patient may well need ITU care
Frequent Observations - Constant or 15 minutely
Medical:
100mg Hydrocortisone stat (IV or IM)
100-200mg hydrocortisone in 5% glucose over 24 hours IV infusion.
Continuous cardiac and electrolyte monitoring – May need Calcium Gluconate
Check patient glucose levels and treat as indicated
Look for and treat underlying cause e.g. sepsis/MI
