Endo Flashcards
Which CN affected in pituitary apoplexy?
acute pituitary hemorrhage. will cause severe HA, bitemporal visual defects, likely adrenal insuff and CN3 paresis.
initial tests for suspecting Cushing
Pick any:
- overnight dexamethasone suppression test
- 24 hour urinary free cortisol assay
- late-night salivary cortisol measurement
tx for hyperecalcemia from granulomatous dz
- decrease calcium/oxalate intake
- avoid sun exposure
- volume expansion
- low dose steroids
T/F: Bisphophonates are safe in CKD
FAlse! Don’t use if CrCl <30
Can use denosumab in renal insuff (monitor for hypocalcemia)
acromegaly testing
Step 1: Measure IGF-1 levels (note: GH fluctuates diurnal so not used)
Step 2: confirmatory testing with oral glucose suppression test (75g glucose). + = GH >2
Step 3: brain MRI (pituitary mass found in 70%)
T/F: statins can worsen hypothyroid myopathy
true and vice versa
Mgmt of pituitary incidentaloma
<10mm: prolactin levels or targeted hormone testing if any sxs
>10mm: check pituitary hormonal functions, consider surgery (can also follow,and prolactinomas respond well to medical therapy)
T/F: Hyperprolactinemia is common in CKD
true. does not respond to HD, can normalize with dopamine agonists however sexual dysfunction often persists due to multifactorial
Difference in presentation of hyperparathyroidism and hypercalcemia of malignancy
HyperPTH: Insidious onset, often asx/mild, Ca elevated mild (<11)
Malignancy: acute onset, significant sxs and severe hyperCa (>13)
Osteoporosis in men should prompt screening for:
Screen for hypogonadism with an early-morning serum testosterone assay
initial eval in hyperthyroid patient without features of Graves
Radioactive iodine uptake (RAIU)
High RAIU scan
Diffuse uptake pattern: Graves
Nodular uptake: Toxic adenoma, Multinodular goiter
Low RAIU
Measure Tg
- decreased: exogenous hormone
- elevated: thyroiditis, iodide exposure, extraglandular production
why is cosyntropin test needed prior to levothyroxine in central hypothyroidism?
This is an ACTH stimulation test. Levothyroxine can precipitate adrenal crisis in patients with concurrent adrenal insufficiency.
Anti-tpo (thyroperoxidase)
chronic lymphocytic thyroiditis aka Hashimoto (PRIMARY HYPOTHYROIDISM WITH ELEVATED TSH)
T/F: Risk of malignancy of thyroid nodule is independent of TSH
False.
Elevated TSH = higher risk malignancy.
Suppressed TSH suggests hyperfunctioning nodule, which is typically benign.
Other descriptors which increase risk of malignancy = >1cm, hypoechoic, vascular, microcalcifications
Hormonal testing after adrenal incidentaloma
All incidental tumors need at least hormone testing.
Must eval for:
- excess cortisol (i.e. overnight dexamethasone suppression test)
- pheo: urinary fractionated catecholamines and metanephrines
If hypertension: plasma aldosterone and aldosterone:renin activity ratio
T/F: Patients with type 2 diabetes and obesity commonly have hypogonadotropic hypogonadism
True. If it is borderline low (200-300), do not routinely need pituitary imaging.
If markedly low (<200) or signs of other pituitary hormone abnormalities, pituitary MRI to eval for mass
Testing in all patients with medullary thyroid cancer
RET mutation genetic testing.
- also eval for co-existing tumors (i.e. metanephrines for pheo) and for mets
- calcium for hyperparathyroidism
- MTC is seen in MEN 2A and 2B
T/F: Hereditary hemochromatosis causes secondary hypogonadism
True. Look for a patient with sick sinus syndrome. Iron deposits in the pituitary gonadotrophs.
Next step when RAIU shows toxic adenoma (mildly elevated, high-normal RAIU) or multinodular goiter with over hyperthyroidism (low TSH, high T4)
Radioactive iodine ablation (definitive tx)….or surgical thyroidectomy
side effects of SGLT2 inhibitors
UTI, hypotension, vaginal candidiasis
**use cautiously if hx of PVD/diabetic ulcer/neuropathy b/c increased risk of LE amputation
**inc in DKA (euglycemic)
**they decrease glucose reab in kidney - osmotic diuresis = hypotension. reduce doses of diuretics
(note, they don’t cause wt loss)
Which DM med causes wt loss
GLP-1 (liraglutide, exenatide, dulaglutide), low risk of hypoglycemia, good add on to metformin . AE = pancreatitis, GI side effects (n/v/d), wt loss
T/F: Hypogonadism is common in men with obesity and diabetes
True, HPA axis dysfunction. If other features are present (loss of body hair, gynecomastia, hot flashes, osteoporosis), should prompt workup for androgen def
initial step in eval of male hypogonadism
morning serum total testosterone level. Next step after testosterone is FSH and LH
(measuring free testosterone is not recommended initially, is expensive and inaccurate)
When would you do MRI of pituitary in workup of hypogonadism?
First check serum total testosterone. If low, check FSH and LH. If low (secondary hypogonadism), it should be considered if severe hypogonadism (testosterone <150), other pituitary deficiencies (TSH, GH), high prolactin or mass effect sxs
Which patients definitely need stress dose steroids perioperatively?
- daily pred for >3 weeks
- any patient who has developed Cushingoid features (including wt gain)
T/F: Subclinical hypothyroidism does not require treatment
False.
Indications for tx: TSH >10
if TSH 7-9.9 and <70, tx
if sxs, enlarging goiter or anti-TPO titer detected, tx
T/F: All patients with central hypothyroidism should undergo neuroimaging and chemical testing
True
especially adrenal, i.e. ACTH stimulation test known as cosyntropin stim test…since giving levo to central patients can precipitate adrenal crisis
workup in a patient with Cushing appearance
- Confirm the dx: abnormal results on 2 screening tests (low dose dex suppression test, 24 hour urine free cortisol, late night salivary cortisol)
- Establish etiology: ACTH independent (low) vs ACTH-dependent (normal/high). Measure ACTH level
- F/u imaging:
ACTH independent usually have a cortisol-secreting adrenal mass or adrenal hyperplasia (CT adrenal glands); ACTH-dependent usually have ACTH-secreting pituitary adenoma (Cushing dz), or ectopic
How do you evaluate a patient with ACTH-dependent Cushings?
-can include high dose dexamethasone suppression tests, corticotropin-releasing hormone stim testing, MRI pituitary, desmopressin stim test, inferior petrosal sinus sampling
Suppression of cortisol following high-dose dex = corticotroph pituitary adenoma
ectopic ACTH secreting tumors will have no suppression of cortisol fellowing high dose dex (resistant to feedback inhibition)
High dose dexamethasone suppresses pituitary ACTH and adrenal cortisol means
source is pituitary. If MRI negative, do intrapetrosal sinus sampling for ACTH to confirm source is pituitary
ACTH is high but high dose dexamethasone does not suppress cortisol production
ectopic tumor is release ACTH. Most common tumors = SCLC, pheochromocytoma, medullary thyroid carcinoma and bronchial carcinoid.
Get chest/abdomen CT
Tx for Cushing syndrome
Surgical resection of the adrenal gland (ACTH independent), pituitary gland (ACTH dependent) or ectopic tumor (ACTH dependent)
Bisphosphonate if low bone density
T/F: Patient found to have an incidental adrenal mass >1 cm but no sxs can be reassured and observed
False. This defines an incidentaloma, all patients require biochemical workup for:
- Cushings: 1-mg overnight dexamethasone suppression test
- Pheo: 24-hour urine metanephrines and catecholamines
**If htn or hypokalemia, measure plasma aldosterone-renin ratio
if no surgical resection, repeat imaging in 6-12 months
Next steps if secondary hypogonadism is confirmed (i.e. low/inappropriately normal LH and FSH)
- check prolactin
- check iron studies to rule out hemochromatosis
- MRI to eval for hypothalamic/pituitary lesions
fever or sore throat in a patient take methimazole or PTU
agranulocytosis until proven otherwise
how do you manage hyperthyroidism in pregnant patient?
No radioactive iodine (in pregnancy or breastfeeding)
PTU in first trimester, then methimazole
side effects of Methimazole and PTU
agranulocytosis
hepatotoxicity (more PTU)
rash
tx of multi-nodular goiter
Radioactive iodine (i-131)…hyperactive nodules take up iodine preferentially, normal tissue gets minimal radiation. freq achieve euthyroidism
common things that decrease levothyroxine absorption
celiac disease
calcium and iron supplements
PPI
managing levothyroxine in pregnancy
increase the dose by 30%
check thyroid function frequently in pregnancy
why are steroids useful in thyroid storm?
Decrease peripheral T4–>T3 conversion and improve vasomotor stability
how does urinary chloride help determine cause of metabolic alkalosis
Vomiting: will be hypochloremic afterwards, so you will reabsorb chloride from urine and thus low urinary chloride
Diuretics/Gittelman/Barter: unable to reabsorb chloride and lose it in urine
When TSH is low, how can you differentiate thyroxtoxicosis from euthyroid sick syndrome
Measure T3 levels. in ESS, hospitalized patients commonly have low T3 due to illness supressing T4–>T3 conversion…treating these patients thyroid is not beneficial, will return to normal w/in a few weeks
T/F: Thyroid nodule with low TSH suggests hyperfunctioning nodule, increasing risk of malignant
False. It does suggest a hyperfunctional (hot) nodule, but these are usually BENIGN aka hyperthyroidism. Do thyroid scan and uptake
How does TSH help guide management of a new thyroid nodule?
Low TSH: Iodine 123 scintigraphy. Hot nodules = tx hyperthyroid. Cold nodules = FNA
Normal/High TSH: FNA
T/F: Thyroid nodules >1cm with normal/elevated TSH typically can be observed
False. These should get FNA. A low tsh is more reassuring than normal/high TSH
laryngospasm after thyroid surgery
- immediate post extubation: bilateral recurrent laryngeal nerve injury
- w/in few hours: wound hematoma
- 24 hours after, with paresthesias/cramps: hypocalcemia
how to manage TG-induced pancreatitis?
Glucose >500: Insulin infusion
Glucose <500/severe pancreatitis: consider plasma exchange (apheresis)
DKA mgmt
- NS (if low Na) or 1/2NS (normal or high Na)
- add D5W @ BG <200
- hold IV insulin if k <3.3; switch to SQ when abel to eat, BG <200, AG <12, HCO3>15 (overlap IV and SQ 1-2 hours)
- add IV K if K+<5.3
long term effects of hyperthyroidism
osteoporosis systolic HTN Atrial fib depression heart failure
Thyroid nodule with suppressed TSH next step
Thyroid scintigraphy
Thyroid nodule with normal/elevated TSH next step
FNA
These drugs are sulfonylureas, which can cause weight gain, hypoglycemia and reduced drug clearance in kidney failure
Glyburide
Glipizide
Glimepiride
GLOW GLucose (hypoglycemia)
T/F: Levothyroxine dose adjustments should be based on TSH
TRUE, not based of a higher or lower T4
mgmt of post-prandial hypoglycemia in patient on BB insulin
reduce bolus insulin (not basal)
why does size of pituitary mass matter?
Micro (<10mm) unlikely to grow large enough for compressive effects (i.e. visual loss)…only tx if specific indications.
Macro (>10mm) requires tx
Effects of hyperprolactinemia (i.e. pituitary tumor)
-supresses gonadotropin secrtion and causes hypogonadism in premenoupausal women = infertility, amenorrhea, hot flashes, osteoporosis
–>tx with dopamine agonist (i.e. cabergoline, bromocriptine)
what time do total serum testosterone levels need to be drawn?
between 7am - 10am (this is when testosterone is highest)
how does hyperthyroidism affect calcium/pth axis
Thyroid increases bone turnover (osteoporosis/fracture risk), expect hypercalciuira. PTH is suppressed, leading to less conversion of 25-vit D to 1,25 - vit d
tx of thyroid corrects emtabolic abnormalities but not lost bone density
How to manage T2DM with suboptimal control on oral therapy
HbA1c:
<10%: Basal insulin therapy (without bolus), target <7% if fail then add prandial
> 10%: Basal plus prandial insulin therapy
how can you tell if thyrotoxicosis is secondary to exogenous/factititous use?
Low thyroglobulin (supressing it with exogenous)
T/F: RAIU (I-131) is good tx for Graves opthalmopathy
False, it can worsen it and thus should be avoided when there are ocular sxs
T/F: PTU has a blackbox warning
True, for fulminant hepatitis/acute liver failure. usually only used in first trimester of pregnancy and in thyroid storm (decreases conversion T4 to T3)
T/F: RAIU for Graves can be used in pregnancy
False, delay pregnancy 6-12 months
T/F: Goal in hypo and hyper is based off of TSH
Usually true.
One caveat is for hyperthyroidism in pregnancy, in this case you aim for free t4 in goal
T/F: Thyroidectomy > RAIU in certain cases
True:
- large goiter
- obstructive sxs
- suspected thyroid cancer
- pregnant patients
- severe opthalmopathy
T/F: Tx women with subclinical hypothyroidism who are pregnant or want to become pregnant
TRUE
What are some labs that can be abnormal when hypothyroid?
Hyponatremia
Hyperprolactinemia
Increased CK, AST
Hypercholesterolemia
What is destructive thyroiditis and why do classic thryotoxicosis drugs (M, PTU) not really work? How would you tx?
Subacute (de Quervain)
Silent (painless)
Postpartum
Causes release of preformed thyroid hormones. Can have pain of thyroid gland. ESR/CRP elevated. Usually a cycle of hyperthyroid, euthyroid, hypothyroid then resolution. Permanent hypothyroidism can follow these syndromes.
Tx: Pain mgmt (NSAIDS or STEROIDS); Sx control (BETA BLOCKER); Tx hypoT (LEVOTHYROXINE). repeat studies in 4-6 months
ACTH Stim test
used to diagnose primary adrenal insufficiency (Addison’s disease).
You can accurately perform it after dexamethasone but NOT after hydrocortisone. it can be done any time of day. Positive test = cortisol <18 after ACTH stimulation.
Primary adrenal insufficiency
Addisons disease. It is a high ACTH state. Disease of adrenal cortex, so will also have low aldosterone (low Na, high K, high Renin. this is why you give fludricortisone as well)
T/F: beta blocker for pheo
false, alpha blocker. beta blocker can cause severe adrenal crisis (HTN)
t/f: random glucose >200 + hyperglycemia is diagnostic
true. otherwise fasting glucose >126, 2 hour glucose test >200, HbA1c >6.5. Need 2 of these tests or the random glucose with sxs
TZDs (pioglitazone) can cause (AE):
fluid retention/heart failure
weight gain
contraindication to GLP-1
personal/fhx of medullary thyroid cancer/MEN2
hx of pancreatitis
severe renal insufficiency
orals for DM if weight loss is desired
GLP-1
Pramlintide
SGLT2 inhibitors
GPS
which oral DM cause hypoglycemia
- sulfonylureas (glipizide, glimepiride)
- Meglitinides (repaglinide, nateglinide)
- pramlintide
- SGLT2 inhibitors (empagliflozin, dapagliflozin)
DKA tx
- insulin (delay if K <3.3)
- potassium when K <5.5
- do 1/2NS + D5 when BG <250
- continue insulin infusion until gap closed
when/how screen gestational DM?
week 24-28 with 75g 2-hour OGTT
T/F: Women with hx of GDM at high risk for developing T2DM and require annual screening following delivery
true
surreptious hypoglycemia
- oral hypoglcyemic agents: C peptide inappropriately high @ time of hypoglycemia, screen for sulfonylurea and meglitinide metabolites
- insulin: c-peptide low
72 hour fast: for insulinoma will have elevated C-peptide and glucose <45
T/F: obtain TSH in all patients with hyperprolactinemia
true. and pregnancy test in women
Urine osmolalithy <200 and inability to increase urine concentration during water deprivation test
Diabetes Insipidus. Desmopressin test: if positive, central and get pituitary MRI. If negative, renal US
tx of nephrogenic DI
lithium induced: stop lithium or add amiloride
otherwise: thiazide diuretic + salt restriction
forms of destructive thyroiditis (release of preformed hormone)
- de quervain (subacute). firm and painful
- silent (painless)
- postpartum
permanent hypotT can follow any of these. ESR elevated often
decreased/no uptake on RAIU scan
Thyroiditis
Iodine load
Surreptious ingestion
vs graves has diffuse homogenous increased uptake
T/F: Avoid radioactive iodone in severe graves opthalmopathy and pregnancy
true
T/F: treat subclinical hypothyroidism when TSH >10 and also women who are pregnant/want to become pregnant
true
goal for TSH when treating hypoT
1-2.5
thyroid nodule imaging
TSH low: RAIU
TSH normal/high: Thyroid US
T/F: FNAB for thyroid nodules >1cm
true, or <1cm and risk for cancer/suspicious US
