Spectrum: Local Antimicrobial Stewardship, for Markham Stouffville Hospital

Echocardiography

SAB and Infectious Endocarditis (IE)

ALL patients with bacteremia should undergo echocardiography to evaluate for IE.

Up to 20% of SAB are associated with IE.

Transthoracic echocardiography (TTE) should be performed first.

TTE

A negative TTE is insufficient to rule out IE when index of suspicion is high.

Transesophageal echocardiography (TEE) is more sensitive than TTE, with highest sensitivity during the first 5-7 days after onset of bacteremia.

TEE

Transesophageal echocardiography (TEE) should be pursued in the setting of risk factors for IE.

Risk Factors for IE

  • For further assessment of anatomy and complications of IE in the setting of a positive TTE

  • Persistent SAB despite appropriate therapy

  • Unknown duration of bacteremia

  • Presence of cardiac prosthetic material

  • Presence of predisposing valvular abnormality

  • Absence of evident removable source of bacteremia

  • Hemodialysis

  • Evidence of vertebral osteomyelitis, discitis or epidural abscess

  • Presence of peripheral stigmata of IE

  • Presence of CHF, heart block or prolonged PR interval

  • Intraveneous Drug Use

TEE can be foregone if ALL the following conditions are met:

  • Nosocomial acquisition of bacteremia

  • Sterilization of follow-up blood cultures within 4 days after initial positive culture

  • No intracardiac device present

  • No hemodialysis

  • No clinical signs of endocarditis or metastatic focus of infection

  • Removable focus of infection removed promptly (if present)

  • Defervescence within 72 hours of initial positive blood culture

Paediatric Echocardiography

Paediatric echocardiography is not necessary for children with catheter-associated bacteremia who do not have other signs of endocarditis, otherwise the same criteria as adults is followed.