Unrein Cushing CIS Flashcards
Addison’s. What would serum cortisol look like?
low basal level of cortisol secretion
how can someone be physiologically normal in their cortisol metabolism yet have either abnormally high or low levels of serum cortisol?
it travels bound to albumin
pregnancy– increased serum proteins/ albumin
severe illness in the ICU/ cachexia– decreased serum proteins/ albumin
how to dx Addison’s disease?
cosyntropin stimulation test
primary adrenal insufficiency– serum cortisol levels do not increase in response to ACTH
secondary adrenal insufficiency- serum cortisol levels do increase in response to ACTH
most common form of adrenal insufficiency?
exogenous steroids
feedback mechanisms not working
distinguishing biochemical features/ hallmarks of adrenal insufficiency?
hyperkalemia
hypoglycemia
hyponatremia,
metabolic acidosis
clinical feature include volume depletion and circulatory collapse in severe cases
how would you distinguish between primary adrenal insufficiency and secondary adrenal insufficiency based on clinical presentation?
secondary adrenal insufficiency does not have the hyperpigmentation nor the severity of electrolytes abonrmalities;
precursor to melanocyte stimulating hormone and CTH are the same.
Primary insufficiency leads to over-production of acth and its precursor through this common pathway. Aldosterone is not affected by ACTH; it is mainly driven by the renin-angiotensin system, maintaining some of the electrolyte balance.
difficult-to-control blood pressure and hypokalemia. What might this be?
mineralocorticoid excess
primary glucocorticoid deficiency presentation
would expect hyperpimented skin, hyperkalemia, hyponatremia, hypoglycemia, volume depletion and hypotension
Glucocorticoid excess presentation
would expect truncal obesity, significantly elevated serum glucose, hypokalemia, hypernatremia, weight gain (obesity) and thin, easily-bruised skin
mineralocorticoid deficiency presentation
this i arare, would present with hyperkalemia and bradycardia due to the elevated potassium, hyponatremia, hypotensiona nd a normal glucose
mineralocorticoid excess
would expect hypernatremia, hypokalemia, BP resistant to treatment. Glucose is normal. This is a direct cause of a metabolic alkalosis because of Na_ retention at the expense of K_ and H_
differences between low dose and high dose dexamethasone suppression test?
low dose - distinguishes adrenal excess from someone normal (just fat)
high dose- distinguishes someone with primary versus exogenous sources of ACTH
cosyntropin stimulation test
used to assess adrenal reserve and differentiate between primary and secondary causes of adrenal insufficiency, not adrenal excess, and measure the changes in serum cortisol
serum AM cortisol level
measures total AM cortisol both protein bound and free cortisol. It could be affected by teh exogenous estrogens and other things that affect protein metabolism
24-hour urine free cortisol level
the first best screening tool to evaluate free cortisol excess
high dose dexamethasone suppression test
used to differentiate pituitary vs extra pituitary sources of excess ACTH secretion
proximal muscle weakness
can be caused by adrenocortical excess
but also many other things like lambert-eaton syndrome, MSK stuff, many others.
guy with COPD, hoarse, new cough, high urine cortisol, on steroids. What should we do?
CT the chest - some clinical features of malignancy of the upper chest. If adrenal excess, more likely an ACTH producing tumor than a primary effect of the metastasis on adrenal glands
guy with pyelonephritis and COPD, every time try to decrease steroids, he has exacerbations of his COPD> Upon hospitalization in addition to antibiotics for hte pyelonephritis you should
administer a stress dose of steroids; he’s sick and needs extra steroids because his adrenal glands are suppressed
stress dose of steroids
suppressed adrenal pituitary axis cannot respond physiologically to stress
patient gets sick, give them extra
how long is someone considered to have adrenal suppression after a prolonged course of steroids?
one year
why is it important to have an intact adrenal pituitary axis in place before starting thyroid replacement?
thyroid picks up the metabolic rate
renal metabolism of cortisol will increase
could precipitate an adrenal crisis and circulatory collapse in a pt that doesn ot have n intact adrenal pituitary axis and therefore unable to respond to stress
someone with hypertension and high sodium has been seeing a chinese herbalist for depression. What might be going on?
many chinese medicines have glycyrrhizic acid in them (licorice)
inhibits degradation of cortisol
same consequences as excess cortisol
serum aldosterone and renin would be low because of excess glucocorticoids in the system (they have mineralocorticoid properties)
guy with sore throat, purpuric rash and palms and soles and headache. Hypotension and unconscious, not vacced. What’s up?
probably neisseiria meningitis
–> waterhouse friedrichson syndrome
(bilateral adrenal hemorrhage)
Waterhouse Friederichsen syndrome
bilateral adrenal hemorrhage
associated with neisseria meningitids
clinical approach to waterhouse friedrichson syndrome?
abx and cortisol
guy has fatigue after 10 yrs ago transsphenoidal hypophysectomy- removal of pituitary adenoma. Has small testes. What test should we order for his fatigue?
serum free cortisol and free T4;
all pituitary hormones are pointless here because there’s no pituitary and they’re probably on replacement hormones anyway
