USMLE Step 3 Latest Update - 300

USMLE Step 3 Latest Update - 300 Questions and 100% Verified Correct Answers Actual Exam Guaranteed A+

• causes of microcytic anemia - CORRECT ANSWER: iron deficiency, lead poisoning,

anemia of chronic disease (but usually normocytic), thalassemia, sideroblastic anemia (can also have high MCV)

Abx safe in pregnancy - CORRECT ANSWER: -PCNs

-cephalosporins -aztreonam -erythromycin -azithromycin

Abx with NO anaerobic coverage - CORRECT ANSWER: aminoglycs, aztreonam,

fluoroquinolones, oxacillin/nafcillin, all cephalosporins EXCEPT cefoxitin and cefotetan

Acanthocytes on blood smear (looks like spur cell but with more rounded spurs) -

CORRECT ANSWER: liver disease, hypothyroidism, alcoholism

Achalasia - CORRECT ANSWER: -high tone LES

-bird's beak on barium swallow -histology shows hypertrophied inner circular muscle with absence of ganglia of Auerbach's plexus -tx with balloon dilation or surgery

Actinomyces - CORRECT ANSWER: -normal immune system w/ facial or dental trauma

-dx with gram stain and confirm with anaerobic cx -branching, filamentous bacteria (LIKE nocardia!) 1 / 4

-tx with PCN

Adequacy of sputum sample - CORRECT ANSWER: <10 squamous cells and >25 leuks per LPF

Adjustment of levothyroxine in pregnancy - CORRECT ANSWER: -INCREASE dose as

soon as pregnancy is confirmed -most pt.s require increase of 25-50% -check TSH once a trimester -checking T3 and T4 not effective b/c these levels are increased during pregnancy due to increased thyroid-binding globulin

Adverse effects of NNRTIs - CORRECT ANSWER: ??

efavirenz nevirapine

Adverse effects of NRTIs - CORRECT ANSWER: lactic acidosis

zidovudine: anemia

didanosine: pancreatitis and peripheral neuropathy

stavudine: pancreatitis and neuropathy

lamivudine: none

abacavir: rash

emtricitabine: none

Adverse effects of protease inhibitors - CORRECT ANSWER: hyperglycemia

hyperlipidemia

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indinavir: kidney stones

ritonavir lopinavir nelfinavir saquinavir darunavir tipranavir amprenavir atazanavir

Aeromonas hydrophila - CORRECT ANSWER: This gram-negative bacterium is found

in freshwater environments, although it may also be present in brackish water.Infections are more likely to occur during warmer weather. Soft tissue involvement and bacteremia/sepsis can develop in patients with underlying immunocompromising diseases, including cirrhosis and cancer. The clinical presentations of infection with Vibrio vulnificus and Aeromonas species can be quite similar. This organism is often susceptible to fluoroquinolones, trimethoprim-sulfamethoxazole, tetracyclines, imipenem, aminoglycosides, and third- or fourth-generation cephalosporins

Alcoholic ketoacidosis - CORRECT ANSWER: -AG acidosis

-increased osmolal gap -ketonemia or ketonuria -variable blood glucose level, but if higher than 250 think DKA -tx with IVF (D5NS) and thiamine

Alcoholic with PNA - CORRECT ANSWER: strep pneumo, oral anaerobes, Klebsiella

pneumo, Acinetobacter, M. tuberculosis

Anaerobes - CORRECT ANSWER: -metronidazole is BEST for abdominal anaerobes

(carbapenems, piperacillin, and ticarcillin have equal efficacy) -cefoxitin and cefotetan are the ONLY cephalosporins 3 / 4

-respiratory anaerobes: clindamycin

Antibiotics for GNRs - CORRECT ANSWER: Cephalosporins: cefepime, ceftazidime

PCNs: piperacillin, ticaricillin

Monobactam: Aztreonam

Quinolones: cipro, levo, gati, moxi

Aminoglycs: gentamicin, tobramycin, amikacin

Carbapenems: imipenem, mero, erta

Antibiotics for MRSA - CORRECT ANSWER: IV: vanc, linezolid, daptomycin, tigecycline; if minor infection, can use oral: TMP/SMX, doxy, minocycline, or maybe clindamycin (there is inducible resistance to clinda though)

Antibiotics for MSSA - CORRECT ANSWER: Oxacillin/nafcillin, dicloxacillin (IV and oral), cefazolin (IV), cephalexin (oral)

Antibiotics for strep - CORRECT ANSWER: PCN, ampicillin, amoxicillin

Antibiotics to use for Staph with PCN allergy - CORRECT ANSWER: cephalosporins if rash only; macrolides, clindamycin, vancomycin, linezolid, daptomycin, TMP/SMX

Antibody test for celiac disease - CORRECT ANSWER: anti-endomysial, tissue

transglutaminase (small bowel bx is best though)

Aspiration PNA - CORRECT ANSWER: gram negative enterics, oral anaerobes

Asymptomatic bacteriuria - CORRECT ANSWER: only treat in pregnant women

Babesiosis - CORRECT ANSWER: -causes hemolytic anemia

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