Flashcards in 10 Endocrinology Deck (55):
Female pt presents with galactorrhea and amenorrhea.
How to workup?
2. hypoT (leads to high TRH, stimulating prolactin)
3. DA blockers (antipsychotics)
-get TSH, Prolactin
If prolactin elevated, get MRI
bromocriptine, cabergoline (DA agonist)
-how to workup
1. high IFG-1 (GH varies too much during day, even though tumor secretes this)
2. glucose supproession test (does giving glucose lower GH?)
-what kills them
-cardiomegaly and diastolic HF
-somatostatin (octreotide) before surgery
Hormones of ant pit (5) vs post pit (2)
post pit has 2: oxytocin, ADH
ant has the rest:
GH, TSH, ACTH, LH/FSH, Prolactin
-how does it present?
-how to dx
Less important hormones lost first: LH/FSH and GH, then TSH, then ACTH (BP)
So, first is reduced libido and menstruation, fatigue, vague sxs
-insulin stim test (induce hypoglycemia, does GH increase?)
-MRI to confirm, replace hormones
-what 2 dx to know, how present?
1. sheehans--ischemic pituitary post-partum
-reduced lactation post-partum is 1st sign
2. apoplexy--pit tumor outgrows blood supply, bleeds
-rapid decompensation--Think sudden HA with vision change and N/V, followed by adrenal insuff, lethargy, coma. Catastrophic.
Tx: replace hormones! (esp cortisol, T4)
MRI shows no pituitary. what is going on
Empty Sella syndrome.
pituitary is located somehwere else.
Male pt presenting with low libido and vision change. think what
Diabetes insipidus tx:
-gentle diuretics (HCTZ +/- amiloride)
-think what 3 categories
1. brain--tumor, infxn, trauma
2. lung--small cell CA, COPD, TB
3. hypothyroid (high TSH can stim ADH)
tx underlying cause (eg head trauma, etc)
-Demeclocyline to induce nephrogenic DI to get rid of free water
Sick euthyroid syndrome
TSH normal, but T4 wacky.
Pt in ICU can get this. Disregard the T4 if TSH is normal!
This is only time to get a rT3 level. (in sick euthyroid rT3 is elevated, confirming sick euthyroid)
When to get free T3 level
Only get if you suspect hyperthyroid (low TSH), but T4 is normal/low
What things affect total T4 level? (2 to remember)
1. estrogen (pregnancy) increases proteins (thyroid binding globulin). So, increased total T4
2. Cirrhosis is low protein. So, low total T4
Female pt with hyperthyroidism sxs. TSH low, T4 high, cold RAIU.
-DDx, and what is next step
1. factitious hyperT
2. struma ovarii
3. thyroiditis (acute stage)
Get thyroglobulin levels. Elevated with T4 production, so struma ovarri and thyroiditis have elevated thyroglobulin.
If low, then factitious!b Can also do Sestamibi scan of ovaries.
Pt with hyperthyroid sxs. You confirm labs--low TSH, high T4.
What is next step, and what results possible?
Do RAIU test
-diffuse nodules--nodular goiter
If thyroid NOT hot, then:
-Thyroiditis (wait for thyroid to calm down, might be temp hypothyroid)
-how to dx
1. anti-TPO (thyroid peroxidase),
2. anti-TG (thyroglobulin).
(these 2 are 90% spec) Definitive is Bx.
Can present with transient hyper and hypothyroidism
Grave's unique sxs (2) among all hyperT
-how to tx
1. exophthalmos--tx with steroids
2. pretibial edema
Thyroid storm tx in what order, mechs
First, IVF and cooling blankets. Then 3 P's
1. Propranolol--reduce HR to increase BP
2. PTU/methimazole--reduce T4 production
3. Prednisone (more likely IV methyprednisolone)--reduce T4-T3 conversion
Iodide can also be used (Wolff-Chaikoff). Thyroid preferential picks up iodide instead of making T4, so temporizing measure. However, if thyroid storm not fixed, that iodide will be used to make more T4! (Wolff-Chaikoff escape)
Thyroid storm, what alarm sxs?
Pt with hyperthyroidism. TSH low, T4 high.
How to know if this is Graves or early Hashi's?
ESR/CRP is elevated in Hashi's only
-how to workup
Get TSH first, even if asx. If euthyroid, then get FNA.
If obvious dx is CA (hx of neck CA), then go straight to excision.
what to remember about each
Papillary--MCC. orphan annie, psammoma, resection with good prognosis
Follicular--"sneaky." FNA cannot dx, spreads hemotogenously. However, full resection and iodine ablation will find and kill all mets.
Anaplasic--bad, chokes esophagus and trachea. Death 1 yr
Medullary--MEN 2a/b, Calcitonin producing (so HypoCa)
diamond, square, triangle with tip
MEN 1--pit, parathyroid, panc
MEN 2a--parathyroid, thyroid medullary, pheo
MEN 2b (lincoln--tall)--mucosal, thyroid medullary, pheo
Only get if suspect sick euthyroid. will be increased, confirming sick euthyroid
-how does this correlate with other thyroid labs
Thyroglobulin is increased when T4 production is increased. So, you can use to see factitious hyperT
-name types and differences
All can present with transient hyperT (can be months), then transient hypoT.
1. Hashi's--stays hypothyroid
2. de Quervain (tender thyroid)
3. silent lymphocytic--eventually recovers.(in hypothyroid state, distinguish from Hashi's with Ab tests)
New Grave's dx
Propranolol first, PTU/methimazole takes time for effect
Prednisone for exophtalmos
Hyperthyroidism meds in pregnancy
'PTU in Pregnancy' but more complicated:
PTU in 1st trimester and women who might become pregnant
Methimazole in 2nd/3rd trimester to reduce liver complication risks that PTU has
Nuclear emergency, what med
Potassium Iodide. Blocks uptake of radioactive iodide in nuclear emergency
Pt with thryoid nodule, asx, euthyroid. FNA is equivocal. Do what next?
RAIU when FNA equivocal.
If cold area, tx as CA
If hot area, tx as toxic adenoma
Follicular thyroid Ca, CT does not show mets
-how to tx
General rule--total thyroidectomy, then radioactive iodine (kills all possible mets)
you suspect hypercortisolism
-DDX and full workup algorithm?
"Low THen High"
4 DDx: Adrenal adenoma, extra-adrenal tumor, pituitary tumor, exogenous steroids
1. low-dose DST overnight, or 24h urine cortisol.
If not suppressed, Cushing's syndrome confirmed. Do:
If low, then primary-hypercort--adrenal tumor or exogenous steroids. MRI/CT.
If high, then:
3. High dose DST
If cortisol suppresses, then Pit tumor. MRI/inferior petrosal sinus sampling.
If cortisol not suppressed, then Ectopic ACTH (small cell/panc CA)
You suspect hyperaldosteronism
DDx: primary (Conn's) vs secondary (renovascular, CHF, cirrhosis, nephrotic)
1. 8am Aldo, Renin, Aldo:Renin. D/C HTN meds beforehand.
Aldo high, Renin high, Aldo:Renin<10: Likely 2ndary. Do Angiogram of renal arteries.
Aldo high, Renin low, Aldo:Renin >20: Likely Primary. Next step:
2. Salt Suppression Test. If Aldo not lowered, then confirm primary. CT/MRI to find tumor.
Hyperaldosteronism. You confirmed primary with Salt suppression test. Now you do CT/MRI looking for adrenal tumor.
What to be careful about
50% of hyperaldo pts have incidentaloma. Don't cut out GOOD ADRENAL
Use Adrenal Vein sampling to confirm mass is indeed the adenoma.
5 P's, +2 more
Pain--HA or chest
Add 2 more P's:
-what dx tests (2)
-what if tumor does not appear on CT/MRI
24h urine metanephrines (better test), or
Urine VMA (cheaper)
If CT/MRI doesn't show, use a MIBG scintillography scan. Can also do Adrenal vein sampling.
You see an adrenal incidentaloma
-Do what tests
-what size importance
R/o the 3 main tumors:
Pheo--24h urine metanephrines/urine VMA
Cushing's--low dose DST
If <4cm, can observe. >4cm or increase in size over time, intervene.
You suspect Adrenal insuff:
how to workup?
Main ddx: Addison's vs Pit issue
1. 3am cortisol. If low, then:
2. ACTH (cosyntropin) stim test, measure cort in 60min
If cort still low, then primary. CT/MRI abd, replace hormones
If cort high, then secondary. MRI head
-tx of primary vs secondary
Primary (Addison's, TB):
Secondary (Pit issue)
1. prednisone only
Migratory necrolytic dermatitis
-what's going on
If pt also has DM, then this is Glucagonoma! CT to find it, resect.
Can also get glucagon level
You suspect insulinoma
-how to dx and confirm
-how to know not factitious?
72h fast, with monitoring for sxs (including sz). Confirm with somatostatin receptor scintigraphy (SRS) test +/- CT scan.
Factitious can be exogenous insulin and sulfonylurea.
-C peptide level (low in exogenous)
Diabetes dx tests (3)
1. Random BGx1, with sxs
2. Fasting BGx2
125+ both times= DM
100-125: do 2h OGTTx1:
200+ = DM
140-200 = pre
<140 = normal
6.5+ = DM
5.7 - 6.5 = pre
-Oral meds max A1C reduction
-insulins max A1c reduction
-What A1C to start insulin?
start insulin at A1C of 9
T2DM treatment approach
1. lifestyle + Metformin
2. if 3 mo not at goal, add 2nd agent, based on comorbidities
3. if 3 mo again, not at goal, start insulin.
-contraindications (3 to know)
CKD (Cr >1.5 males, 1.4 females)
side effects and contraindications:
-diarrhea (goes away)
-CKD (lactic acidosis), CHF
-reduced dose in CKD (b/c hypoglyc risk)
-weight gain, CHF risk
T2DM uncommon med classes
-ex brand names
1. DPP4-i (sitagliptin)
2. GLP-i (exenatide)
4. SGLT2-i (canagloflozin)
1. weight neutral
2. weight loss
3. diarrhea, flatulence
4. DKA risk
Outpt insulin regimens
-what are the 2
-mixed ('idiot insulin'): 2x/daily 70/30 humulin or novolin
-how to do it the right way
Basal bolus (+Sliding scale). Remove oral meds.
1. Calculate TDI (total daily insulin) = 0.5U/kg unless Cr high. If TDI
1. Somogyi effect, vs
2. Dawn phenomena
-how to diff
1. (rebound hyperglyc) too much insulin at night, high AM glucose. Body responded by making more glucose, then insulin wore off by AM.
2. to little insulin at night, high AM glucose.
Check 3AM glucose to diff!
If high, then Dawn
If low, then Somogyi
-describe main steps to discharge
1. start NS, check e-lytes
2. If K <4.0, give KCl and don't give insulin yet
3. K good, Give insulin.
4. keep giving insulin until AG closes. If hypoglyc, switch to D5 1/2NS
5. once AG closed, stop insulin drip and bridge with long-acting SQ insulin. Have pt eat. If AG still closed, go home.
Young adult, no hx diabetes, comes to ED for polydipsia, polyuria, fatigue.
Suspect what, check what labs
Could be DKA vs HHS
ketones (serum, urine): +
BMP: no AG, but possible contraction alkalosis! Also pseudohypoNa.
ABG: no acidosis
HHS: could see metabolic alkalosis (contraction) causing slow breathing, leading to hypoxia and hypercapnia (intubate!). Coma, unresponsive.