Flashcards in Addison's/ Adrenal insufficiency Week 6 Deck (20)
problem in adrenal insufficiency/ Addison's
(Addison's is the most common cause of PRIMARY adrenal insufficiency) decreased secretion of steroids- cortisol (glucocorticoid) aldosterone (mineralcorticoid) and androgen
why does primary adrenal insufficiency happen?
90% autoimmune, body attacks adrenal cortex (associated w/ other autoimmune stuff- type 1 DM, autoimmune thyroid dx, pernicious anemia and ovarian failure) other rarer causes- hemorrhage/ traumatic injury, cancer, adrenal gland TB
s/s of adrenal insufficiency- remember low "steroid"
S sodium/ sugar both low (salt cravings reported)
E electrolyte imbalance- potassium, calcium (increase)
R reproductive changes- women have irregular menses/ loss of body hair, men have erectile dysfunction
O lOw BP- risk for vascular collapse/ shock
I increased pigmentation/ hyperpigmentation (common at buccal mucosa, also at pressure points, recent scars, or skin creases)
D diarrhea/ nausea/ anorexia, depression
Addisonian crisis aka adrenal gland crisis s/s
Addisonian crisis tx
need urgent management- (fatal if left untreated, can make official dx later- start treatment if suspected) Give dexamethasone initially (4 mg IV) while the basal cortisol measurement and the cosyntropin stimulation test are performed; empiric treatment with IV hydrocortisone (100 mg IV q8h, with rapid tapering) can then be initiated. Also need D5NS to correct volume depletion, dehydration, and hypoglycemia. Should be in the ICU
long term tx for adrenal insufficiency
All patients with chronic adrenal insufficiency require replacement with glucocorticoids (aka cortisol) and occasionally with mineralocorticoids (aka aldosterone). Hydrocortisone is frequently used in primary adrenal insufficiency because it has some mineralocorticoid activity. The usual dosage of hydrocortisone is 10 to 15 mg every morning and 5 to 10 mg in the afternoon. When prednisone is used, typical doses are 2.5 to 5 mg daily. If additional mineralocorticoid effect is necessary for persistent hyperkalemia and/or orthostatic hypotension, fludrocortisone 0.05 to 0.2 mg once a day may be added (cortisol replacement= prednisone or hydrocortisone) (aldosterone replacement= Fludrocortisone aka Florinef).
aka Addison's- most common cause of primary adrenal insufficiency
Autoimmune adrenalitis is associated with ?
increased levels of 21-hydroxylase antibodies
most common cause of central (secondary/tertiary) adrenal insufficiency is
withdrawal of glucocorticoids after long-term use
primary adrenal insufficency mainly from?
common presenting sign of adrenal insufficiency ?
classic laboratory abnormalities found with adrenal insufficiency
hyponatremia and hyperkalemia.
hyperkalemia is due to ?
mineralocorticoid deficiency (aldosterone)
hyponatremia occurs mainly due to ?
glucocorticoid deficiency (cortisol) It is the result of elevated vasopressin values with free water retention, shift of extracellular sodium into cells, and decreased delivery of filtrate to the diluting segments of the nephron due to decreased glomerular filtration rate
Mild to moderate hypercalcemia
Fasting blood glucose is usually low-normal (if pt also has type 1 DM, hypoglycemia prob more severe)
How is adrenal insufficiency usually diagnosed?
In the outpatient setting, a low morning cortisol value (< 3 μg/dL) is sufficient to diagnose adrenal insufficiency, and a high morning cortisol value (> 20 μg/dL) excludes the diagnosis.
In most instances, a dynamic test called what is also performed?
cosyntropin stimulation test- determines whether the adrenals are able to respond to maximal stimulation by synthetic ACTH
How is the cosyntropin test performed?
by collecting a specimen for measurement of a baseline serum cortisol level, administration of 250 μg of cosyntropin (brand name Cortrosyn, Synacthen) IV or IM, and then collecting specimens for serum cortisol measurement 30 and 60 minutes later. An abnormal result is defined as a stimulated cortisol level at either 30 or 60 minutes of less than 18 to 20 μg/dL (< 450-500 nmol/L). can be done at any time of day. If pt is receiving glucocorticoid therapy, the dose should be withheld (12 hours for hydrocortisone, 24 hours for prednisone) before the test is performed to avoid detection of synthetic glucocorticoids in the cortisol assay
Other dynamic testing includes
the insulin tolerance test, metyrapone test, glucagon stimulation test, and CRH stimulation test