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Flashcards in Adrenal Insufficiency Deck (38):
1

cortisol binds ___ in plasma

CBG

(also albumin to lesser extent)

2

primary vs secondary adrenal insuf clinical presentation differ because

in primary, aldosterone is also absent

3

adrenal venous drainage

right adrenal vein to posterior IVC

 

left directly to left renal vein

3

ACTH secreting neoplasms in Cushings have a higher set point for ____

glucocorticoid negative feedback

3

earliest biochemical finding in cushings

lack of nadir or cortisol secretion late at night

4

pathophysicology ACTH independent hypercortisolism

solitary tumor or bilateeral adrenal nodular disease

ACTH low in patients due to corisol negative feed back, making contralteral adrenal small

5

lab abnls in adren insuf

hyperkalemia (primary)

hypercalcemia, hypoglycemia (rare in adults)

lymphocytosis

5

Rx cause of pituitary disease related secondary adrenal insufficiency

ipilimumab

6

Primary adrenal insufficiency =

Secondary adrenal insufficiency = 

Teritiary adrenal insufficiency = 

 

impaired production of cortisol from adrenal cortex due to dysfunctional adrenal gland

 

diseases of pituitary (ACTH def)

 

diseases of hypothalamus (CRH def)

6

2 caveats for cortisol testing outcomes

1. chronically ill may have low binding proteins - low total cortisol with normal free levels

(estrogen, contraception may increase cortisol levels reflecting increase in binding proteins with no adrenal dyfunction

 

2. adrenal androgen production is a sensitve marker of adrenal reserve and normal levels are very rare in adrenal insuff

7

concurrent disorders common with adrenal insuff

critical illness with hypotension

pituitary diseasse

TBI

Brain radiation 

8

explanation of skin pigmentation changes with marke ACTH elevation 

presence of alpha melanocyte stimulating hormone amSH within peptide hormone complex POMC from which ACTH is processed from

8

Rx causes of adrenal insuff

Withdrawal from corticosteroids

narcotics (supress CRH/ACTH)

Ketoconazole, etomidate, mitotane (adrenostatic/lytic)

mifepristone (glucocorticoid receptor antagonist)

9

presenting symptoms adrenal insufficiency

fatigue, low energy

nausea/vomiting/weight loss

hypotension > dizzyness, orthostasis

increased skin pigmentation and salt craving (primary)

9

response to acute adrenal crisis

Admin hydrocortisone 100mg IV every 6hrs for 24hr

once stable, taper 50mg every 6 hours and then taper to maintenance

11

porgesterone compound used to stimualte apetite and cause suppression of ACTH and cortisol 

megestrol acetate

12

congenital causes of adrenal insuf

congenital adrenal hyperplasia

adnrenoleukodystrophy (X-linked with accumulation of very long chain FAs in adrenals and brain) 

13

normal cortisol response to ACTH//Cosyntropin

peak resposne at 30 or 60 min >18ug/dL (500nmol/L)

14

Treatment and Rx for Cushings syndrome 

Surgery (ressection or bilateral adrenalectomy if refractory)

Radiotherapy

Pasireotide - somatostating receptor antagoinist

Metyrapone - 11-betahydroxylase inhibitor (p450 c11)

Mifepristone - glucocorticoid receptor antagonist 

16

cortisol exerts ___ feedback on CRH/ACTH

negative

17

presenting symptoms that raise suspicion for Cushings

Weight gain (truncal)

SUpraclavicular and dorsocervical fat 

facial rounding and plethora

proximal muscle weakness

Hirsutism, angrogen excess in females

Wide violaceous stria 

Easy bruising, cutaneous atrophy

Cognitive difficulty, depression, psychosis

19

Cortisol mechanism of action

Binds gluccocorticoid receptor > 

> dissociation of heat shock proteins + dimerization >

> dimers translocate to nucleus > enhance glucocorticoid related genes.

21

in 17-hydroxlyase deficiency, ____ makes up for deficiency of corisol

corticosterone

22

causes of primary adrenal insuf

Autoimmune

Adrenal hemorrhage (associated with coagulopathis, bilateral)

Infectious (TB, histoplasmosis, coccidiomycosis, HIV)

Genetic

Infiltrative (amyloidosis, hemochromatosis)

Drugs (ketoconazole, metyrapone, mititoane, etomidate)

(Autos Are Infectious, Impressive Diversions)

23

injectable hydrocortisone for emergent use

Solu-Cortef

24

if in suspected ACTH dependent Cushings, if MRI of pituitary is normal or equivocal >

 

outcomes?

bilateral pitrosal sinus sampling with ACTH admin

 

no gradient = occult ectopic ACTH

gradient = cushings disease

25

Drugs associated with primary adrenal insuf

Ketoconazole

metyrapone

mitotane

etomidate

26

diagnostic tests for cushings

Late night salivary cortisol - lack of nadir

 

Overnight dexmethasone supression test - normal suppression = cortisol

 

24 hour urine free cortisol (poor senstivity)

28

ACTH is processed from ___ inside the pituitary gland corticotropj

POMC

30

initiating process in cortisol synthesis

cholesterol import into mitochondrion via StAR protein

31

first step in DDx for Cushings

 

outcomes?

measure  plasma ACTH

 

Low = independent Cushings > Adrenal CT

 

Normal or elevated = ACTH dependent > MRI of pituitary

32

glucocoritcoid receptor antagonist used for endogenous hypercortisolism

 

mifepristone

33

in kidney, cortisoal metabolized to cortisone via

 

and converted back to cortisol via ____ inside the _____

 11B-HSD2

 

back via 11B-HSD1 in liver and visceral fat

34

aldosterone pathway in zona glomerulosa is stimulated by 

ang II

Potassium

ACTH

35

diagnoses that raise suspicion for Cushings

Diabetes/HTN/metabolic syndrome

Osteoporosis

Adrenal nodules

36

intitial evalulation of suspected adrenal insuff

 

follow-up

morning cortisol

 

cosyntropin stimulatory test of adrenal reserve

37

steroid production in zona fasciculate controlled by 

ACTH (via hpyothalamus)

CRH

AVP

(also negative feedback(

38

lab findings Primary vs secondary adrenal insuf

Pimary High ACTH

HIGH PRA

low Aldosterone

 

Secondary: low-normal ACTH

normal PRA

normal aldosterone