Endocrine and Metabolic Conditions Flashcards
(347 cards)
Addison’s Disease Definition
Adrenal insufficiency is a clinical syndrome that arises due to the insufficient production of glucocorticoids and mineralocorticoids from the adrenal cortex.
It can be categorized as primary, commonly known as Addison’s disease, where the cause lies within the adrenal glands themselves, or secondary, where inadequate stimulation of the adrenal glands by the pituitary or hypothalamus is the culprit.
Difference between primary and secondary adrenal insufficiency
In primary adrenal insufficiency (Addison’s disease), the adrenal glands are damaged, while secondary adrenal insufficiency is due to dysfunction in the hypothalamus or pituitary.
Name causes of primary adrenal insufficiency
Auto-immune destruction (most common)
Surgical removal of the adrenal glands
Trauma to the adrenal glands
Infectious diseases, such as tuberculosis (more common in developing countries)
Haemorrhage (e.g., Waterhouse-Friderichsen syndrome)
Infarction
Less commonly, neoplasms, sarcoidosis, or amyloidosisAuto-immune destruction (most common)
Name causes of secondary adrenal insufficiency
Congenital disorders
Fracture of the base of the skull
Pituitary or hypothalamic surgery or Neoplasms in the pituitary or hypothalamus
Infiltration or infection of the brain
Deficiency of corticotropin-releasing hormone (CRH)
Signs and symptoms of Addison’s disease
Hypotension
Fatigue and weakness
Gastrointestinal symptoms
Syncope
Skin pigmentation due to increased ACTH which stimulates production of alpha melanocyte stimulating hormone (MSH).
In the case of auto-immune Addison’s disease, approximately 60% of patients may also have vitiligo or other autoimmune endocrinopathies.
First line investigations for Addison’s disease:
U+E and serum cortisol, where you may find:
Hyponatraemia (low sodium)
Hyperkalaemia (high potassium)
Low serum cortisol
Glucose (typically low)
What would you expect a blood gas to show in someone with Addison’s disease?
hyperkalaemic, hyponatraemic, hypoglycaemic metabolic acidosis
With less aldosterone, there is a reduced excretion of hydrogen ions, leading to their buildup in the blood. This causes an increase in the acidity of the blood, resulting in metabolic acidosis.
Name some other findings one would expect in Addison’s disease
ACTH: High in primary insufficiency, low or low-normal in secondary insufficiency
Renin (high in Addison’s disease)
Aldosterone (low in Addison’s disease)
What is the gold standard investigation
for Addison’s disease?
An ACTH (Short Synacthen) test is the gold standard investigation to confirm the diagnosis.
Name further investigations for addison’s disease:
Testing for adrenal auto-antibodies
Chest X-ray for tuberculosis
CT scan of the adrenal glands
MRI of the brain
Management of adrenal insufficiency:
Patient education on ‘sick day’ rules, carrying a steroid card, and wearing a medical alert bracelet
Doubling the regular steroid medication dose during any intercurrent illness
Replacement of both glucocorticoids (typically with hydrocortisone) and mineralocorticoids (typically with fludrocortisone)
Regular screening for complications including an adrenal crisis and osteoporosis
Management of Addison’s crisis:
Aggressive fluid resuscitation
Administration of intravenous/IM (if no access) steroids STAT
Glucose administration if hypoglycaemia is present
What is the most likely cause of Addison’s disease?
autoimmune
What does severe meningococcal infection cause with the adrenal gland?
Waterhouse-Friderichsen syndrome
Thought that meningococcal septicaemia is associated with disseminated intravascular coagulation (DIC) which leads to adrenal haemorrhage.
If someone take steroids for a long time and then suddenly stops what might this cause? (think adrenals) and what do we give?
Secondary adrenal insufficiency - give IV Hydrocortisone
what part of the adrenal gland is mineralocorticoid produced?
Zona glomerulosa
What part of the adrenal gland produces glucocorticoids?
zona fasciculata
First step of management for an adrenal crisis?
immediate administration of intravenous or intramuscular hydrocortisone 100 mg in adults
What is Cushing’s syndrome?
endocrine disorder characterized by excess glucocorticoids
What is Cushing’s disease?
glucocorticoid excess caused by an adrenocorticotropic hormone (ACTH)-secreting pituitary tumour
What are the two main category causes of Cushing’s syndrome?
ACTH-dependent disease
ACTH-independent
What causes ACTH-dependent cushings?
pituitary tumor (Cushing’s disease) or ectopic ACTH-producing tumors (e.g. lung carcinoids, thymic carcinoids, and others).
What causes ACTH-independent cushings?
C: cancer adrenal adenoma
A: adrenal nodular hyperplasia
R: Rare causes: McCune-Albright syndrome
Steroid use
What are the signs and symptoms of cushings?
Proximal myopathy
Striae and easy bruising
Osteoporosis and fractures
Glucose intolerance or diabetes mellitus
Obesity, particularly truncal or “centripetal” obesity
Hypertension
Hypokalaemia
Facial changes, such as moon face and acne
Hirsutism in women
Fat redistribution leading to interscapular and supraclavicular fat pads
Thin extremities due to muscle wasting
Thin, fragile skin
Erectile dysfunction in men
Psychological issues, such as depression or cognitive dysfunction
Osteopenia or osteoporosis