Endocrine #5 (Adrenal Disorders) Flashcards
(41 cards)
In Addison’s Disease (Primary Chronic Adrenocortical Insufficiency), the adrenal gland is not making enough _______.
Causes of Addison’s Disease
Cortisol
Adrenal Gland Destruction (lack of cortisol AND aldosterone)
-Autoimmune (MC) in US
-Infection MC in developing countries
-Others: TB, Trauma, Ketoconazole, Rifampin, HIV
Symptoms of Addison’s Disease
-Symptoms due to lack of cortisol
–Sparse axillary and pubic hair
–Fatigue, weakening
–Hypotension (orthostatic)
–Hyperpigmentation (in waist line, fat creases, ORAL 1st)
–Salt craving
–Loss of libido, amenorrhea, n/v, weight loss
Explain the hypothalamus-pituitary-adrenal axis and how this affects cortisol
-Hypothalamus secretes CRH to stimulate pituitary gland to secrete ACTH to stimulate adrenals to secrete cortisol
Therefore, what do labs show in PRIMARY adrenocortical insufficiency?
-Elevated ACTH
–8AM ACTH, cortisol, and renin levels
–Increased renin levels in primary
However, in SECONDARY adrenocortical insufficiency, what labs are expected?
-Decreased ACTH
What other labs are obtained in primary (Addison’s) adrenocortical insufficiency?
-Hypoglycemia
-Hyperkalemia
-Hyponatremia
-Metabolic Acidosis
What is the effect of cortisol on blood sugar?
Cortisol raises blood sugar by releasing stored glucose.
Therefore, if cortisol is LOW, blood sugar will be low. Hypoglycemia is expected in Addison’s Disease.
What labs are diagnostic for chronic adrenocortical insufficiency?
Low plasma cortisol, elevated ACTH
What screening test can be done for primary adrenocortical insufficiency (Addison’s)?
High-dose ACTH Cosyntropin stimulation test
–Insufficiency (<18) or absent rise in serum cortisol after ACTH administration IV or IM
-Normal response is rise in serum cortisol
-Check after 60-90 minutes to determine if there is a rise or not
Treatment for Addison’s Disease (Primary Adrenocortical Insufficiency)
-Glucocorticoid Replacement: Oral hydrocortisone
-Mineralocorticoid Replacement as well: Fludricortisone if positive for Addison’s
Because cortisol is a stress hormone, people with chronic adrenal insufficiency must be treated with ______ and ________ before and after surgical procedures (mimicking the body’s natural response)
-IV Glucocorticoids and IV isotonic fluids
What is Adrenal (Addisonian) Crisis?
-Acute adrenocortical insufficiency: sudden worsening of symptoms precipitated by stressful event (illness, surgery, trauma, MI, fever) or abrupt withdrawal of glucocorticoids (MC)
Normal response to stress is a 3-fold increase in cortisol, but these patients cannot meet the demand.
Symptoms of Addisonian Crisis
-All the same symptoms of Addison’s Disease (salt craving, hyperpigmentation, muscle pain) + high fever, hypotension, hypovolemia (SHOCK)!!!!
Although the labs are the same as in Addison’s Disease, what are they?
-Hyponatremia, hyperkalemia, hypoglycemia
–Cortisol and aldosterone confirms diagnosis
Treatment for an Addisonian Crisis
-Isotonic fluids (normal saline or D5N5) + IV hydrocortisone or Dexamethasone
-Reversal of electrolyte disorders
-Fludricortisone
Back to chronic adrenocortical insufficiency, explain a secondary cause pathology and what is low in this condition?
Pituitary failure of ACTH secretion (lack of cortisol only). Aldosterone intact due to renin angiotensin aldosterone system (RAAS)
Primary Adrenocortical Insufficiency:
Secondary:
Lack of cortisol AND Aldosterone
Lack of cortisol only
What is Cushing’s Syndrome?
Syndrome: symptoms and signs related to cortisol excess.
There are exogenous causes of Cushing’s Syndrome and endogenous causes. Explain both.
Exogenous: long-term high dose glucocorticoid therapy
Endogenous:
-Cushing’s Disease (pituitary gland ACTH overproduction (pituitary adenoma) MCC)
-Ectopic ACTH-producing tumor (small cell lung cancer, etc.),
-Adrenal tumor (Adenoma) that secretes excess cortisol
Symptoms of Cushing’s Syndrome
-Proximal muscle weakness
-Weight gain
-Fat Redistribution: Central obesity, moon facies, Buffalo hump, supraclavicular fat pads, thin extremities
-Skin Changes: Striae, acanthosis nigricans, easy bruising, poor wound healing
-Androgen Excess: hirsutism, acne, oily skin
-Hypertension
What happens when the body recognizes there is low cortisol or experiencing stress?
(H-P-A axis)
Hypothalamus releases CRH that stimulates the pituitary to release ACTH to stimulate adrenal gland to secrete cortisol
What vision changes are expected with Cushing’s Syndrome?
Bitemporal vision changes
What are three screening tests for Cushing’s Syndrome?
-24 hour urinary free cortisol (most specific)
-Nighttime salivary cortisol
-Low dose (1mg) overnight Dexamethasone suppression test
What is expected on the Dexamethasone suppression test if the patient has Cushing’s?
-Elevated cortisol or no suppression with low dose Dexamethasone
