HY USMLE REVIEW
PART I
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HY USMLE Review – Part I
Travel + self-limiting watery or brown/green diarrhea à Traveler diarrhea = ETEC HL or HS toxin
Bloody diarrhea + poultry consumption à Campylobacter jejuni or Salmonella spp.
Abx (clindamycin, beta-lactam, cephalosporin) + diarrhea à C. difficile
Dx of C. diff à stool AB toxin test, not stool culture
Fever of 104 + abdo distension in C diff à toxic megacolon à laparotomy
Tx of C. diff à vancomycin, not metronidazole (updated guidelines as of Feb 2018)
Bloody diarrhea + travel à Entamoeba histolytica
Tx of E. histolytica à metronidazole + iodoquinol; can give paromomycin
Close quarters or military barracks or cruise ship + watery diarrhea à Norwalk virus
Child <5 years + watery diarrhea à rotavirus
Few organisms causing bloody diarrhea à Shigella
Bloody diarrhea + appendicitis-like pain (pseudoappendicitis) in a child à Yersinia enterocolitica
Bloody diarrhea + reactive arthritis in an adult à Y. enterocolitica, Campylobacter, Shigella, Salmonella
Diarrhea + Guillain-Barre syndrome à Campylobacter
GBSyndrome CSF? à albuminocytologic dissociation (high protein + normal cells)
GBSyndrome Dx? à electromyography + nerve conduction studies (on NBME)
Cardiac ischemia + need to evaluate à ECG stress test first-line
Cardiac ischemia + abnormal baseline ECG (e.g., BBB) à Echo stress test (need normal ECG to do ECG stress
test)
Cardiac ischemia + patient can’t exercise à dobutamine + ECG/echo
ECG shows diffuse ST-segment elevations à pericarditis
Pericarditis Tx à NSAID, or steroid, or colchicine
Central chest pain worse when supine; better when leaning forward à pericarditis
Lateral chest pain after viral infection + increased CK à pleurodynia (intercostal muscle spasm)
ST-segment depressions in the anterior ECG leads à posterior MI
Electrical alternans on ECG à pericardial tamponade / pericardial effusion
Pulsus paradoxus (drop in systolic BP >10 mm with inspiration) à cardiac tamponade or severe asthma
Beck triad à hypotension + muffled heart sounds + JVD à pericardial tamponade
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