WBR1060

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Author [[PageAuthor::Mohamed Moubarak, M.D. [1]]]
Exam Type ExamType::USMLE Step 3
Main Category MainCategory::Primary Care Office
Sub Category SubCategory::Cardiovascular
Prompt [[Prompt::A 35 year-old male comes to your office complaining of fever, along with chills, anorexia, malaise, and chest pain. These symptoms started suddenly over the last 5 days. His past medical history is not significant. He smoke one pack of cigarette per day for the last 10 years, and drink alcohol occasionally. He is sexually active, and use I.V drugs with the recent use one week ago. On examination, his temperature is 102.9°F (39.4° C), blood pressure 140/90 mmgH, heart rate 100/min, and respiratory rate of 21/min. There is a painful, red, raised lesion on the finger pulps. His chest x-ray shows patchy infiltrations, and his echocardiography shows tricuspid valve vegetation. What is the best next step in managing this patient?]]
Answer A AnswerA::Blood culture and wait for the results to start antibiotic therapy
Answer A Explanation [[AnswerAExp::Incorrect

The rapid progression of acute cases necessitates the start of empirical treatment antibiotic therapy once the blood cultures have been collected]]

Answer B AnswerB::Blood culture and start antibiotics before the results
Answer B Explanation [[AnswerBExp::Correct

The rapid progression of acute cases necessitates the start of empirical treatment antibiotic therapy once the blood cultures have been collected]]

Answer C AnswerC::Start empiric antibiotics immediately
Answer C Explanation [[AnswerCExp::Incorrect

Blood cultures have to be drawn first]]

Answer D AnswerD::Start with thrombolytic therapy to prevent more emboli
Answer D Explanation [[AnswerDExp::Incorrect

Anticoagulants can cause or worsen hemorrhage in patients with endocarditis but may be carefully administered when needed.]]

Answer E AnswerE::Order EKG
Answer E Explanation [[AnswerEExp::Incorrect

Blood cultures have to be drawn first]]

Right Answer RightAnswer::B
Explanation [[Explanation::This is an acute case of infective endocarditis, it is diagnosed according to the Duke clinical criteria, which include:
  • Two major criteria, or
  • One major and three minor criteria, or
  • Five minor criteria

Major Criteria 1.Positive blood culture for infective endocarditis 2.Evidence of endocardial involvement: which include positive echocardiogram for infective endocarditis Minor criteria:

  • Predisposition: predisposing heart condition or intravenous drug use
  • Fever: temperature > 38.0° c (100.4° f)
  • Vascular phenomena: major arterial emboli, septic pulmonary infarcts, mycotic aneurysm, intracranial hemorrhage, conjunctival hemorrhages, and janeway lesions
  • Immunologic phenomena: glomerulonephritis, osler's nodes, roth spots, and rheumatoid factor
  • Microbiological evidence: positive blood culture but does not meet a major criterion as noted above (see footnote) or serological evidence of active infection with organism consistent with infectious endocarditis
  • Echocardiographic findings: consistent with infectious endocarditis but do not meet a major criterion as noted above

Antibiotic therapy for subacute hemodynamically stable disease, and in those who have received antibiotics recently can be delayed waiting for the results of blood cultures, as this delay allows an additional blood cultures without the confounding effect of empiric treatment. On the other hand, the rapid progression of acute cases necessitates the start of empirical treatment antibiotic therapy once the blood cultures have been collected.
Educational Objective:
References: ]]

Approved Approved::No
Keyword [[WBRKeyword::Infective endocarditis]]
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