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Flashcards in Adrenal Pathophysiology Deck (34):
1

What are three main hallmarks of Cushing's syndrome?

1. Loss of diurnal variation of cortisol secretion
2. Autonomy from "central" ACTH control (loss of response to feedback inhibition)
3. Excess cortisol secretion

2

What are two broad categories of of Cushing's syndrome?

ACTH-dependent and ACTH independent

3

What is most common cause os Cushing's Syndrome?

Exogenous use of glucocorticoids
Next is Cushing's disease (ACTH producing pituitary adenoma)

4

What are basic metabolic derangements due to excess corticosteroids? (3)

Stimulates gluconeogensis: hyperglycemia
Increases lipogenesis, insulin resistance: increased FFA
Increased gluconeogenesis results in catabolism of proteins

5

Signs and symptoms of Cushing's Syndrome: Effects of fat metabolism (4)

Dewlap (neck)/round face
Supraclavicular fat pads
Buffalo hump
Skinny limbs with big stomach

6

Other effects of cortisol excess: immunity, hematopoetic, eyes and musculoskeletal (3)

Impaired immunity
Hypercoagulability
Cataract formation
MS: proximal myopathy, osteoperosis, redistribution of body fat

7

What are cardiovascular effects of cortisol excess? (3)

Hypertension, cardiomyopathy, increased thromboembolic events (atherosclerosis, strokes, PE, etc)

8

What are dermatological effects of cortisol excess? (6)

Thin skin
Easy bruisability
Striae
Acne
Hyperpigmentation
Hirsutism

9

What are CNS effects of cortisol excess? (2)

Pyschiatric disturbances
Cognition/psychosocial functioning

10

What are mineralocorticoid and androgen effects of excess cortisol? (4)

HTN and hypokalemia (hk more associated with ectopic ACTH production)
Testosterone increased in females
Abnormal menses
Marked virilization worrisome for malignant adrenal tumor

11

ACTH-dependent Cushing's is characterized by ______

Bilateral adrenal hyperplasia

12

What hormone levels do we observe in ACTH-independent Cushing's? Why?

High cortisol; low ACTH
This is because cortisol is providing negative feedback on ACTH

13

How do you measure loss of diurnal variation of cortisol secretion?

Late night salivary cortisol: measures free cortisol and can be easily collected at home

14

Dexamethasone suppression: what it does....why do you do it?

Exogenous dexamethasone substitutes for ACTH in suppressing ACTH release
Should have low cortisol....if not, it indicates inappropriate cortisol secretion

15

24 hour urinary free cortisol: what indicates Cushing's?

If cortisol > 3x upper limit of normal

16

How do you localize source of problem?

Look at plasma ACTH-- if low, Cushing's is from adrenal source....if high, Cushing's from pituitary or ectopic ACTH source....also if exogenous, ACTH is low

17

Treatment of Cushing's: Unilateral adrenal adenoma

Adrenalectomy

18

Treatment for pituitary adenoma

Hypophysectomy

19

How long do symptoms of hypercortisolism take to resolve?

Up to 12 months
Not all sequelae completely resolve (especially psych ones0

20

Primary adrenal failure (Addison's disease): main features (4)

90% of cortex destroyed before presentation
Elevated ACTH
Usually indolent course
Can lose adrenal hormones

21

Symptoms of primary adrenal failure are consistent with ____ and _____ deficiency, and include _____ (3)

Mineralocorticoid and glucocorticoid deficiency

Hyponatremia, hyperkalmeia, hypotension

22

Clinical characteristics of primary adrenal failure: (6)

Hyperpigmentation
Weight loss
Muscle/joint pains
Fatigue
Nausea, abdominal pain
Hypoglycemia (reduced gluconeogenesis)

23

Etiologies of Addison's Disease (5)

Autoimmune destruction (60%)
Infectious: TB, fungus, HIV
Bilateral hemorrhage/infarct
Metastatic cancer
Drugs: aminoglutethimide, ketoconazole, etomidate, rifampin, phenytoin

24

Diagnosis of Addison's disease (2)

Early AM cortisol/ACTH concentration: look for low cortisol and high ACTH

Cosyntropin stimulation testing: look at IM injection of synthetic ACTH and measure cortisol

25

What is an adrenal crisis? What are the clinical characteristics? (big list)

Acute deficiency in cortisol/mineralocorticoids

Hypotension, shock, fatigue, weakness, malaise, fever, lethargy, abdominal pain/nausea/vomiting, anorexia, hypoglycemia

26

Etiologies of Adrenal Crisis (4)

New primary adrenal failure
Known adrenal insufficiency with acute illness or under-replacement of meds
Acute withdrawal of high dose glucocorticoids
Pituitary apoplexy

27

Treatment of Adrenal Crisis (3)

Rehydration: saline IV and electrolytes
Dexamethasone
Monitor BP

28

Autoimmune adrenalitis are associated with _____

Other autoimmune disorders-- polyglandular syndromes
Type 1: hypoparathyroidism, candidiasis, primary hypogonadism
Type 2: T1DM, autimmune thyroiditis, vitiligo, hypogonadism

29

Primary Hyperaldosteronism: Findings (5)

Mineralocorticoid excess:
Hypertension, hypokalemia, hypernatremia, metabolic alkalosis, muscle weakness

30

Who should be screened for primary hyperaldosteronism? (4)

Pts under 30 with HTN, no obesity or family history
Pts with unexplained hypokalemia and hypertension
Pts with resistant HTN
Ptts with adrenal incidentaloma/HTN

31

Dx of Primary Hyperaldosteronism

Look at aldosterone: renin ratio

>20 suggestive, but not diagnostic

32

What do you do for hyperaldosteronism patients over 35? Why?

Sample adrenal vein prior to surgery-- differentiate between unilateral adenoma and bilateral adrenal hyperplasia

33

How do you distinguish unilateral adenoma vs. bilateral hyperplasia?

Lateral disease has aldosterone concentration 4x greater than the contralateral side

34

How do you treat unilateral adenoma vs. bilateral hyperplasia?

Unilateral aldosterone-secreting adenoma: surgical resection

Bilateral adrenal hyperplasia: mineralocorticoid antagonist