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20 Cards in this Set
- Front
- Back
Adrenal Insufficiency:
AKA Presentation |
Addison's Syndrome
Specific: Volume depletion, hyperkalemia, hyperpigmentation General: fatigue, weakness, weight loss, GI complaints, low BP PRESENTATION IS VARIABLE |
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Primary vs Secondary AI
GC function MC function ([Na+], [K+], blood volume) ACTH levels (pigmentation) Pituitary function |
Primary:
Lose GC Lose MC (sodium + volume loss; potassium retention) High ACTH (lack negative feedback; hyperpigmentation) Normal pituitary fn Secondary: Loss GC MC okay (no hyperkalemia) LOW ACTH (no hyperpigmentation) Hypopituitarism |
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Why does primary AI result in hyperpigmentation?
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ACTH receptor and alpha-MSH receptors come from same receptor line
When tons of ACTH, ACTH will bind alpha-MSH receptors |
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Autoimmune adrenalitis:
Effects Antibodies Present Affiliated Syndromes |
Major cause of AI
Adrenal Ab's (21-OHase Ab) May be part of polyglandular autoimmune syndrome PRIMARY AI |
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Polyglandular Autoimmune Syndromes:
Type I vs Type II |
Type I:
APECED Autoimmune polyendocrinopathy Chronic mucocutaneous candidiasis Ectodermal dysplasia (abnormal development of the skin, hair, nails, teeth, or sweat glands) Results in hypopara, AI, and hypogonadism Type 2: HLA-related Affects multiple endocrine systems, most commonly AI, thyroid, and DM I PRIMARY AI |
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Cause of AI in undeveloped countries
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Tb
Fungal CMV HIV PRIMARY AI |
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Waterhouse-Friederichson Syndrome is an example of ___________ which can result in _____.
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Adrenal hemorrhage (in pts with meningococcal sepsis) and can result in AI
(Clues of adrenal hemorrhage: hypotn, shock, abdominal/flank pain, fever, DROP IN Hg) PRIMARY AI |
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Metastatic Causes of AI (cancer types)
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BrCa
Lung Ca PRIMARY AI |
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What drugs interfere with adrenal function?
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Ketoconazole (antifungal)
Etomidate (anesthetic) PRIMARY AI |
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Congenital Adrenal Hyperplasia:
Relevance to AI |
Impaired production of cortisol
PRIMARY AI |
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Adrenoleukodystrophy:
Relevance to AI |
Defect in oxidation of FA's in peroxisomes-->elevated serum levels of long chain FA's-->accumulation in cell membranes
leads to PRIMARY AI |
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Familial Glucocorticoid Deficiency
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Defect in MCR-2 (Melanocortin Receptor--an ACTH receptor), can't make cortisol
Can make ACTH Zona glomerulosa not affected, so can make MC PRIMARY AI |
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Causes of Secondary AI
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EXOGENOUS GLUCOCORTICOIDS
(Suppress HPA axis, adrenals atrophy) Pituitary/CNS tumors (visual changes, thunderclap tumors) Hemorrhage into tumors SHEEHAN'S SYNDROME |
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Cortrosyn stimulation testing:
Describe Normal values? How would results vary based on time since onset of secondary AI? |
Cortrosyn stimulation testing (CST):
Large dose of ACTH (CST) then measure cortisol normal peak >18-20 If primary AI, will have below 18-20 NOT GOOD FOR SECONDARY AI OF RECENT ONSET bc they'll look nrml (non-atrophied zona fasciculata If it's been a while from onset, shouldn't get an increase in cortisol (atrophy!) |
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How would you screen for secondary AI?
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Insulin tolerance:
Hypoglycemia = stress-->stimulates HPA Give IV insulin to induce hypoglycemia (<45 gm/dl) (not that safe, use one below) OR Metyrapone testing (blocks last step in cortisol synthesis): Normally 11-deoxy cortisol low but if block it's conversion to cortisol, cortisol levels will fall, inc'd CRH, inc'd ACTH, inc'd 11-deoxy cortisol (11-DOC) If have a problem in pit gland, give metyrapone at bedtime, measure in morning CRH would be low, 11-DOC doesn't go up |
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How do ACTH levels vary with primary/secondary AI?
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If primary AI, ACTH HIGH
If secondary AI, low or inappropriately nl |
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Glucocorticoids:
Use AE's Examples (include MC affinity) |
Use: Treat AI
AE's: signs of Cushing's, problems when steroids are withdrawn (can take a year to recover!) Prednisone Cortisol, Cortisone (binds MC) Dexameth (doesn't bind MC as much affinity as Cortisol) |
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Fludrocortisone:
Mechanism Use |
Fludrocortisone; potent synthetic MC
Use: Primary AI (need to stimulate MC's) Note: some GC drugs have MC props at high doses |
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Traditional dosing of glucocorticoid replacement is based on ________.
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Circadian rhythms and daily fluctuations of cortisol levels
So higher dose in AM, lower dose in PM (no good method for biochemical monitoring so if pt feels good, dose is okay) |
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What is adrenal crisis?
Causes? Treatment? More prominent in Primary or Secondary AI? Why? |
Presentation of AI as hypotensive shock unresponsive to fluid resuscitation and pressors
Could be due to loss of HPA fn, abrupt withdrawal of HPA Suppression tx Omission of adrenal replacement tx in known AI Failure to increase adrenal replacement when necessary for acute stress (Surgery, Illness) More common in primary Ai bc of combined GC and MC deficiencies Tx: Stress dose steroids for serious illness or sx, doses tapered as pt improves (2-4x usual dose of steroids) Pts should wear Medic-alert bracelet! |