questions 9

Endocarditis

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Topic updated on 11/21/17 3:35pm

Snapshot
  • A 43-year-old man with a history of IV drug abuse reports fever, chills, cough, and pleuritic chest pain for several days. He has an episode of hemoptysis in the ER. Physical exam reveals a temp of 39 degrees Celsius, scattered rales, and a II/VI systolic murmor at the lower left sternal border that increases with inspiration. A lesion is found on the palm of his hand.
Introduction
  • Inflammation of the heart valve, usually secondary to infection
  • Usually left-sided
    • unless patient has a history of IV drug use in which case it is usually
      • right-sided
      • involving  tricuspid valve
  • Acute endocarditis caused by
    • Streptococcus pneumoniae
    • Streptococcus pyogenes
    • Neisseria gonorrhoeae
    • Staphylococcus aureus (especially in IV drug users)
  • Subacute bacterial endocarditis has
    • slower onset of symptoms with less severe symptoms
      • caused by
        • Enterococcus: the source is typically from a cystoscopy in the setting of a UTI
        • S. viridans: the source is typically an upper respiratory infection 
        • Staphylococcus epidermidis: the source is typically the skin
  • Murantic endocarditis occurs
    • due to metastatic cancer seeding to the valves
      • commonly associated with cerebral infarcts due to malignant emboli
      •  very poor prognosis
  • Libman-Sacks endocarditis caused by
    • systemic lupus erythematous (SLE)
    • usually asymptomatic but murmur can be heard
  • Risk factors include
    • history of RHD
    • valvular heart disease
    • IV drug use
    • immunosuppression
    • prosthetic heart valve
  • Common cause of "fever of unknown origin (FUO)"
  • Intravascular infection that can spread to other organs 
    • must watch for signs of neurologic, joint, and lung manifestations
Presentation
  • Symptoms
    • patients present with range of symptoms that may include
      • high fever that can last for weeks
      • cough
      • SOB
      • systemic symptoms (weakness, fever, malaise)
  • Physical exam
    • heart auscultation
      • usually reveals a murmur
      • often mid-systolic of tricuspid regurgitation over LLSB
    • Osler's nodules 
      • small, red-purple, tender nodules on fingers and toes
      • immune-mediated small-vessel vasculities in response to long-standing micro-abscesses
    • Janeway lesions
      • non-tender, dark macules on palms and soles 
      • result from septic micro-embolisms
    • Roth spots
      • retinal hemorrhages 
    • subungal petechiae (splinter hemorrhages)
Evaluation
  • Diagnosis based on Duke Criteria (1994, revised 2000)
    • major criteria include
      • positive blood cultures
      • evidence of endocardial involvement
    • minor criteria include:
      • predisposing heart condition or history of IV drug use
      • fever
      • vascular phenomena, including major arterial emboli, septic pulmonary infarcts, mycotic aneurysm, intracranial hemorrhage, conjunctival hemorrhages, and Janeway lesions
      • immunologic phenomena, including glomerulonephritis, Osler’s nodes, Roth’s spots, and rheumatoid factor
      • blood cultures not meeting major criteria
      • echocardiographic findings not included in major findings
  • Blood cultures  
    • positive blood cultures drawn at least 12 hours apart 
    • or 
    • multiple positive cultures (at least 3 of 4) with the first and last drawn at least 1 hour apart
  • Echocardiography 
    • look for vegetations
    • negative echo does not rule out endocarditits
  • CXR
    • may reveal septic emboli in right-sided endocarditits
Differential
  • Osteomyellits, abscess, pneumonia, rheumatic fever, prostatitis in males, STDs in females, other causes of FUO
Treatment
  • Empiric prolonged antibiotic therapy
    • treat fo 4-6 weeks
      • recent evidence shows 2 weeks OK for certain organisms
      • tailor for organism based on cultures 
  • Surgical valve replacement 
    • indicated in cases with
      • worsening valve function
      • abscess formation
      • conduction disturbance (arrhythmia)
Prognosis, Prevention, and Complications
  • Prognosis is good
  • May prevent secondary infection with prophylactic antibiotics (amoxicillin or erythromycin) before dental work
  • Complications occur secondary to embolic phenomena as described

 



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Qbank (2 Questions)

TAG
(M2.CV.41) A 65-year-old male with a medical history significant for hypertension, coronary artery disease, prostate cancer, mitral valve repair 10 years ago, and recurrent urinary tract infections (UTIs) s/p cystoscopy one month ago presents to your office with a three week history of general malaise, weakness, fever, and chills. On exam, the patient appears ill. His temperature is 101.5 degrees F, blood pressure is 145/88 mmHg, pulse is 92/min and regular, and respirations are 14/min. On cardiac auscultation, you note a new III/VI systolic murmur. You also notice a lesion on his hand (shown). Which of the following organisms is likely responsible for his present illness? Topic Review Topic
FIGURES: A          

1. Staphyloccocus aureus
2. Staphylococcus epidermidis
3. Viridans streptococci
4. Enterococci
5. Neisseria gonorrhoeae

PREFERRED RESPONSE ▶
TAG
(M2.CV.185) A 36-year-old woman with a long history of a heart murmur presents with one week of increasing fatigue and low-grade fevers. She had a dental cleaning two weeks ago. She denies any hematuria, neurological symptoms, or changes in the appearance of her hands and fingernails. Her past medical history is otherwise insignificant. On physical exam, her temperature is 38.1 C (100.6 F), heart rate is 92/min, blood pressure is 118/67, and respiratory rate is 16/min. She appears fatigued but in no acute distress. Cardiac auscultation reveals a III/VI holosystolic murmur best heart at the cardiac apex in the left lateral decubitus position. Pulmonary, abdominal, and extremity exams are within normal limits. An echocardiogram is performed and is shown in Figure A. The patient is started on empiric IV vancomycin and gentamicin. Three days later, 4/4 blood cultures grow Streptococcus viridans that is highly sensitive to penicillin. What is the next best step in management? Topic Review Topic
FIGURES: A          

1. Continue IV vancomycin and gentamicin
2. Switch to oral penicillin V
3. Switch to oral amoxicillin/clavulanate
4. Stop vancomycin and continue IV gentamicin
5. Switch to IV ceftriaxone

PREFERRED RESPONSE ▶
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