Adrenal Insufficiency Flashcards

1
Q

cortisol binds ___ in plasma

A

CBG

(also albumin to lesser extent)

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2
Q

primary vs secondary adrenal insuf clinical presentation differ because

A

in primary, aldosterone is also absent

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3
Q

adrenal venous drainage

A

right adrenal vein to posterior IVC

left directly to left renal vein

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3
Q

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

A

glucocorticoid negative feedback

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3
Q

earliest biochemical finding in cushings

A

lack of nadir or cortisol secretion late at night

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4
Q

pathophysicology ACTH independent hypercortisolism

A

solitary tumor or bilateeral adrenal nodular disease

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

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5
Q

lab abnls in adren insuf

A

hyperkalemia (primary)

hypercalcemia, hypoglycemia (rare in adults)

lymphocytosis

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5
Q

Rx cause of pituitary disease related secondary adrenal insufficiency

A

ipilimumab

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6
Q

Primary adrenal insufficiency =

Secondary adrenal insufficiency =

Teritiary adrenal insufficiency =

A

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

diseases of pituitary (ACTH def)

diseases of hypothalamus (CRH def)

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6
Q

2 caveats for cortisol testing outcomes

A
  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

  1. adrenal androgen production is a sensitve marker of adrenal reserve and normal levels are very rare in adrenal insuff
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7
Q

concurrent disorders common with adrenal insuff

A

critical illness with hypotension

pituitary diseasse

TBI

Brain radiation

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8
Q

explanation of skin pigmentation changes with marke ACTH elevation

A

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

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8
Q

Rx causes of adrenal insuff

A

Withdrawal from corticosteroids

narcotics (supress CRH/ACTH)

Ketoconazole, etomidate, mitotane (adrenostatic/lytic)

mifepristone (glucocorticoid receptor antagonist)

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9
Q

presenting symptoms adrenal insufficiency

A

fatigue, low energy

nausea/vomiting/weight loss

hypotension > dizzyness, orthostasis

increased skin pigmentation and salt craving (primary)

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9
Q

response to acute adrenal crisis

A

Admin hydrocortisone 100mg IV every 6hrs for 24hr

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

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11
Q

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

A

megestrol acetate

12
Q

congenital causes of adrenal insuf

A

congenital adrenal hyperplasia

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

13
Q

normal cortisol response to ACTH//Cosyntropin

A

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

14
Q

Treatment and Rx for Cushings syndrome

A

Surgery (ressection or bilateral adrenalectomy if refractory)

Radiotherapy

Pasireotide - somatostating receptor antagoinist

Metyrapone - 11-betahydroxylase inhibitor (p450 c11)

Mifepristone - glucocorticoid receptor antagonist

16
Q

cortisol exerts ___ feedback on CRH/ACTH

17
Q

presenting symptoms that raise suspicion for Cushings

A

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
Q

Cortisol mechanism of action

A

Binds gluccocorticoid receptor >

> dissociation of heat shock proteins + dimerization >

> dimers translocate to nucleus > enhance glucocorticoid related genes.

21
Q

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

A

corticosterone

22
Q

causes of primary adrenal insuf

A

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