UWS3 Endocrine Flashcards
What are the trimester-specific ranges for TSH?
1st TM: from 0.1 to …
2nd TM: from 0.2 to …
3rd TM: from 0.3 to …
Total T3 and total T4 during pregnancy are how many folds of normal values?
1.5-fold
Screening for hyperthyroidism during pregnancy
TSH
Definition of delayed puberty in boys
testes volume <4 mL by age 14
How does OCP affect thyroid hormone level?
OCP contains estrogen –> estrogen stimulates TBG production –> increased TBG causes decreased free T3/T4 –> functional hypothyroidism
Another name for the following thyroiditis:
- de Quervain thyroiditis
- Hashimoto’s thyroiditis
- de Quervain thyroiditis = subacute granulomatous thyroiditis
- Hashimoto’s thyroiditis = chronic lymphocytic thyroiditis
DDx btw de Quervain thyroiditis vs Hashimoto’s thyroiditis
- de Quervain thyroiditis: tender goiter
- Hashimoto’s thyroiditis: nontender goiter
Other than Hashimoto’s thyroiditis, anti-thyroid peroxidase is elevated in
Hashimoto’s thyroiditis and its variants:
- postpartum thyroiditis
- silent thyroiditis
Definition of postpartum thyroiditis =
<1 yr after pregnancy
DDx btw Hashimoto’s thyroiditis vs postpartum/silent thyroiditis
- Hashimoto’s thyroiditis: permanent hypothyroidism
- postpartum/silent thyroiditis: transient hypothyroidism
Do strict glycemic control decrease the risk of macrovascular and microvascular complications of diabetes?
Macrovascular: No
Microvascular: risk of neuropathy decreased in DMT1 but not in DMT2; retinopathy and nephropathy - yes, decrease
Do toxic thyroid nodules need FNA?
No, hyperfunctioning nodules are rarely cancer
2-step management of toxic thyroid nodules
1) pretreatment with antithyroid medications to achieve euthyroid state
2) definitive treatment with radioactive iodine ablation or surgery
Which 2 antithyroid drugs are commonly used? Which drug is preferred for most patients? Which drug is preferred for first TM of pregnancy?
1) methimazole - most pts
2) propylthiouracil (PTU) - first TM; risk of hepatotoxicity
Complications of subclinical hypothyroidism
pregnancy complications (eg, recurrent miscarriages)
Nonpitting tibial edema is the complication of (hypothyroidism/hyperthyroidism).
hyperthyroidism (Graves disease)
Definition of subclinical hypothyroidism and its workup
Subclinical hypothyroidism = elevated TSH with normal FT4 - check anti-TPO - treat pts if elevated
diabetes + erythematous skin rash with central clearing
glucagonoma - characteristic “necrolytic migratory erythema (NME)”
Definition of precocious puberty
presence of secondary sexual characteristics in boys <9 yr and girls <8 yr
Central vs peripheral precocity in boys
Central: start with testicular enlargement
Peripheral: no testicular enlargement
Classic vs nonclassic congenital adrenal hyperplasia (CAH)
Classic CAH: complete absence of 21-OH; present with salt-wasting at birth
Nonclassic CAH: reduced activity of 21-OH; no salt-wasting hence not identified at birth - presented with precocious puberty instead
Definition of primary amenorrhea
absence of menarche by age 15 if breast development present by age 13
primary amenorrhea + normal breast development + absence of axillary/pubic hair
Androgen insensitivity syndrome
- primary amenorrhea - absence of uterus/ovaries (46, XY)
- normal breast development - testosterone aromatized into estrogen
- absence of axillary/pubic hair - androgen insensitivity
What is iodine-induced hyperthyroidism (Jod-Basedow phenomenon)?
Iodine (eg, in radiocontrast or amiodarone) serves as a substrate for autonomous thyroid nodule (formed by chronic iodine deficiency)
What is Nelson’s syndrome?
Bilateral adrenalectomy - low cortisol - high CRH - development of pituitary adenoma
Before sending pts with medullary thyroid cancer for thyroidectomy, what should be ruled out?
pheochromocytoma (part of MEN type 2) - undiagnosed pheochromocytoma might cause hemodynamic instability during durgery
Treatment of Graves disease during pregnancy is aimed at maintaining a (mild hypothyroid/euthyroid/mild hyperthyroid) state.
mild hyperthyroid - overtreatment with antithyroid during pregnancy might cause fetal hypothyroidism
Why serum calcium may be normal in secondary hyperparathyrodism?
high PTH level may normalize previously low calcium
Which tests are used to monitor antithyroid drugs response?
Serum free T4 and total T3
Screening of gestational diabetes and its normal results
1-hr 50 g OGTT at 24-28 wk (normal <140)
Confirm diagnosis of gestational diabetes
3-hr 100 g OGTT
Target blood glucose for gestational diabetes
fasting <95
1-hr postprandial <140
2-hr postprandial <120 (compre to general population: postprandial <140)
What is the treatment for abnormal TFT with elevated T4 and low T3 after taking amiodarone?
No treatment needed - pts are clinically euthyroid in “low T3 syndrome” and the condition normally resolves spontaneously in a few months
Screening tests for pheochromocytoma
1- plasma free metanephrine
2- 24-hr urinary metanephrine and catecholamine
Intraoperative complications of pheochromocytoma removal and their prophylaxis or management
1- hypertensive crisis - prevented by preop alpha blocker (phentolamine)
2- hypotensive crisis - managed by aggressive fluid
Algorithm for pheochromocytoma diagnosis
1- plasma free metanephrine or urinary metanephrine and catecholamine
2- abdominal MRI
3- if abdominal MRI negative, MIBG scan
Management for incidentally found small pituitary mass which does not affect any hormonal function
followup by repeated pituitary MRI (in 6-12 mo)
Most common cause of congenital adrenal hyperplasia (CAH)
21-hydroxylase deficiency
Medication used for large sulfonylurea overdose
octreotide - inhibits insulin secretion from pancreas
Long-term metabolic effect of prolactinoma
osteoporosis (d/t low gonadotropin levels)
Management of asymptomatic subclinical thyrotoxicosis
followup with repeated TFT as normalization occurs frequently
Under which circumstances gastrin could be falsely elevated?
1- hypercalcemia
2- PPIs
Indications for parathyroidectomy
1- symptomatic hypercalcemia or serum Ca >1 above normal (i.e. >11.5)
2- end-organ complications: osteoporosis, CKD, nephrolithiasis, or increased risk of complications (i.e. UCa >400)
3- age <50 (very likely to develop complications later in life)
Hypothyroidism was found incidentally during preop workups before emergency CABG. Best next step?
Proceed with surgery - Hypothyroidism only slightly increases intraoperative risk.
OHA that could cause hypoglycemia
1- sulfonylurea
2- meglitinides
How to adjust mealtime insulin before exercise - decrease dosage vs complete hold?
decrease dosage - complete skip might precipitate DKA
When should we add IV dextrose during management of DKA?
when BG <200
4 criteria to stop insulin infusion in DKA management
1- AG <12
2- HCO3 >15
3- BG <200
4- able to tolerate oral fluid
Indications for treatment of subclinical thyrotoxicosis
1- TSH <0.1
2- age >65
3- high risk for complications: heart disease, osteoporosis
Most common presentations of nonfunctioning pituitary adenoma
commonly arise from gonadotrophs which are dysfunction
- hypogonadism and low gonadotropin levels
- increased alpha subunits levels
- prolactin only mildly increased (d/t compression of pituitary stalk)
Management of pituitary adenoma which compresses on adjacent structures
trans-sphenoidal surgery - to provide rapid relief of neurological symptoms
Indications for bisphosphonates therapy
1- T score <2.5
2- FRAX-calculated 10-yr risk for major fracture >20% or hip fracture >3%
3- personal history of fragility fractures
What is Pemberton’s sign?
facial plethora and neck veins engorgement after raising arms d/t substernal thyroid extension that causes obstructions
Medications for severe diabetic neuropathy
1- TCA
2- duloxetine (SNRI)
3- certain anticonvulsants (gabapentin, pregabalin)
Clinical presentatiosn of hereditary hemochromatosis
- presents at age 40-60
- bronze diabetes
- central hypogonadism (iron deposition in pituitary)
- hepatomegaly with elevated LFT
Before proceeding to definitive surgery, what workup should be done for newly diagnosed papillary thyroid cancer?
neck US for staging - if mass <1 cm, thyroid lobectomy (only one side) may be attempted
