NBME Q failures Proctored Exam Complete Solutions 100% Correct.

81yo woman w massive PE from DVT has PC 160,000. One week after pharmacotherapy PC 55,000. Thrombocytopenia from which drug? - correct answer NBME 17 Heparin potentiates action of antithrombin III - HIT - development of IgG antibodies against heparin-bound platelet factor 4 25yo woman w 6mo hx of joint pain. poorly responsive to tx with ASA. PE bilat. swelling of PIP, MCP, wrists. Weakness of grasp. Small nodules palpated beneath skin and joints of fingers. Dx? - correct answer NBME 17 RA even though she's 25... 58yo man with SVT refractory to pharmacotherapy undergoes ablation of accessory pathway in atrial endocardium. Which areas should be avoided to leave SA node intact? - correct answer NBME 17 junction of SVC and RA 35yo woman with abnormal pap smear. microinvasive cervical carcinoma. what microscopic feature led to this diagnosis? - correct answer NBME 17 neoplastic cells in sub-basement membrane CT 16yo boy with no signs of puberty. sexual development is tanner stage 2. circumcised penis on PE. testes soft and small-volume 5mL (NL20-30). Firm, non-tender, appropriate size prostate. No lesions or discharge. Serum testosterone concentration is prepubertal. Which hormone measurement in serum most likely determines whether decreased serum testosterone concentration is lack of pituitary hormone stimulus in pt? - correct answer NBME 17 LH 14yo boy w daily headaches for 2moi. headaches described as bilateral aching in temples. boy "has not been himself" for the past few months according to mom. Pt seems confused, forgets names, dates, places, clumsy with frequent falls. School performance has declined. PE - broad-based ataxic gait. Pt alert, oriented to person, place, time, slow to answer questions. Chronic abuse of which substance? - correct answer NBME 17 inhaled glue, paint, etc. - toluene (methylbenzene, toluol, phenylmethane) toxicity - aromatic hydrocarbon C7H8 - highly lipophilic - readily crosses BBB - affects voltage and ligand gated ion channels - inhibits NMDA channels - neuropsyhosis, cerebral/cerebellar degeneration, ataxia, choreoathetosis, optic/peripheral neuropathies, decreased cognitive ability, anosmia, optic atrophy, blindness, tinnitus, hearing loss pt progress from carcinoma to terminal phase. must inform. pt says "it's bad news, isn't it?" you say? - correct answer NBME 17 Yes, it is. -- be straightforward, don't say "tell me how you're feeling" 30yo woman training for marathon, running 20miles daily. fasting serum glucose is 60. after glucose stores depleted, which organs in addition to liver release newly produced glucose in this pt? - correct answer NBME 17 gluconeogenesis occurs primarily in liver, but also happens in kidney and intestinal epithelium. -- muscle cannot participate in gluconeogenesis since it lacks glucose6phosphatase. 80yo woman with suspected temporal arteritis (TA). ESR = 100. Tx involves glucocorticoids, which can have serious adverse effects. pretest probability for TA is 50% in this pt. ESR has 99% sensitivity, 60% specificity. Based on results of ESR testing, what is the most appropriate next step in management? - correct answer NBME 17 additional testing to confirm diagnosis of TA - Bx +/- CRP -- -- this question is not about GCA, more about stats part, because in reality, you'd give steroids right away. - need bx to confirm diagnosis, want to be highly suspicious of TA before biopsying temporal artery. - extremely unlikely that ESR is falsely elevated as high as 100, so repeat ESR is useless. - Post test probability (PPV) is 71% [99/(99+40)]. 80yo woman comes to ED with 2d hx of "feeling funny". "i have lost my pep," has poorly controlled HTN. started medication 2 weeks ago but does not recall name of medication. BP130/85. PE NL. Serum K 3mEq/L. which drug is cause of condition? - correct answer NBME 17 HCTZ - increased urine K - resulting serum K decrease clonidine - correct answer α2 agonist - decreases peripheral vascular resistance - lowers BP - specificity toward presynpatic α2 in brainstem. - decreases presynpatic Ca levels - inhibits release of NE - decreased sympathetic tone AE - dizziness, xerostomia, hypotension, orthostatic hypotension, fatigue 62 yo man develops pericardial friction rub 3d after acute MI. Most likely cause of friction rub? - correct answer NBME 17 fibrinous pericarditis - occurs 3 days post MI -- dressler syndrome (weeks after) - AI fibrinous pericarditis -- LV failure happens secondary to LV infarction, VSD (3-5d), free wall rupture (5-14d), papillary muscle rupture with MR (2-7d) 42yo woman w 1mo hx of abdominal pain after eating fatty acids. BMI31. jaundice, tenderness of RUQ abdomen. Increase in which liver function is most likely to be seen in this patient? - correct answer NBME 17 cholesterol synthesis -- pt likely has biliary colic from cholesterol stones - female, fat, fertile, forty (risk factors 3/4 met) - estrogen increases HMGCoAR activity (increase cholesterol synthesis), increases lipoprotein receptors on hepatocytes (increase cholesterol uptake) pigment stones are due to - correct answer NBME 17 hemolysis (black) infection (brown) Crohn disease chromic hemolysis alcoholic cirrhosis advanged age biliary infection TPN 28 yo woman at 18 weeks w palpitations. increased serum total T4 concentration. what confirms diagnosis of hyperthyroidism? - correct answer NBME 17 free T4 test -- during pregnancy and OCP use, increased levels of TBG (estrogen increases TBG levels). Thus increase of total T4 in pregnancy. Free T3 and T4 should be unchanged. If free T4 is changed - may indicate hyperthyroidism hyperlipidemia drug inhibiting cholesterol transport through intestinal wall? - correct answer NBME 17 Ezetimibe - prevents cholesterol absorption at small intestine brush border - AE rare increased LFT, diarrhea Bile acid resins - correct answer cholestyramine colestipol colesevelam bile acid resin MOA - correct answer prevent intestinal reabsorption of bile acids, increases HMGCoA reductase activity since liver must use cholesterol to make more 80yo man, bedridden, confused. T96, HR100, BP85/50. BP unchanged after IV infusion of 1L isotonic saline. CO - high PCWP - low SVR - low what is the most likely cause of hypotension? - correct answer NBME 17 Distributive shock early septic shock - warm dry skin - ↓ PWCP - ↑ CO - ↓↓ SVR Distributive shock TX - IV fluids - Pressors (NE in sepsis) - abx if infective PWCP indicates? SVR indicates? - correct answer PWCP = preload SVR = afterload shock due to CNS injury - skin? - PWCP? - CO? - SVR? Treatment? - correct answer Distributive shock CNS injury - warm dry skin - ↓ PWCP - ↓ CO - ↓↓ SVR Distributive shock TX - IV fluids - Pressors (NE in sepsis) - abx if infective cardiogenic shock due to? - skin? - PWCP? - CO? - SVR? -- TX? - correct answer Due to acute MI, HF, valvular dysfunction, arrhythmia - cold clammy skin - ↓ or ↑ PWCP - ↓↓ CO - ↑ SVR -- Cardiogenic shock TX - Inotropes - dobutamine - Diuresis obstructive shock due to? - skin? - PWCP? - CO? - SVR? -- TX? - correct answer Due to cardiac tamponade, pulmonary embolism, tension pneumothorax - cold clammy skin - ↓ or ↑ PWCP - ↓↓ CO - ↑ SVR