Antimicrobial Stewardship (AMS)

• Staphylococcus aureus most common 
• Non-β-hemolytic streptococci such as 
  • S. gallolyticus (bovis), S. sanguinis, S. mitis, S. mutans, S. salivarius
• Enterococcus spp.
• HACEK group (Haemophilus sp., Aggregatibacter sp., Cardiobacterium hominis, Eikenella corrodens, and Kingella sp.)

Last reviewed January 2023

• Refer to modified Duke Criteria for diagnostic criteria (see below)
  • Should be considered in patients with persistent fever of unknown source
  • Septic emboli without another cause
• Obtain at least 2 sets of blood cultures from different venipuncture sites prior to antimicrobials
  • If non-acute presentation and clinically stable, obtain 3-4 sets of blood cultures separated over 24-48 hours before initiating antibiotics
  • Antibiotics given prior to cultures is most common cause of culture-negative IE
• ECG on presentation and serially
  • New AV block (including 1st degree block) is associated with periannular complications
• Urinalysis for hematuria
• Echocardiogram
  • TEE more sensitive than TTE
  • If initial TEE negative but high suspicion for IE, repeat examination within 3-5 days is reasonable
• Chest radiography to assess for septic emboli
• Physical examination focused on assessment for metastatic sites of infection such as joint infection or vertebral osteomyelitis/discitis
• Dental evaluation to assess for source of infection

Last reviewed January 2023

• Multidisciplinary involvement recommended as needed: ID, Cardiology, Cardiovascular Surgery, Neurology, Addictions Medicine
• Obtain 2 sets of blood cultures every 48 hours until negative to document clearance
• Duration of therapy is counted from date of first negative blood culture
  • If tissue culture from valve replacement is positive, restart therapy duration from time of operation (unless patient is still bacteremic at time of surgery)
• For regimens involving >1 antimicrobial, agents should be administered temporally close together

Last reviewed January 2023

• Clinically stable with a non-acute presentation: antimicrobials can be deferred while awaiting the results of blood cultures and other diagnostic tests
• Vancomycin and Ceftriaxone 2g IV q24h, reassess when blood culture results are available

Last reviewed January 2023

• For definitive treatment based on microorganism, refer to American Heart Association guideline tables (https://www.idsociety.org/practice-guideline/endocarditis-management/)

Synergy

• Do not need to add with initial management, can await blood culture results
• Gentamicin synergy
  • Used in IE due to:
    • Enterococcus spp. native or prosthetic valve
    • Staphylococcal prosthetic valve for initial 2 weeks of therapy
    • Some Streptococci depending on penicillin MIC
  • Verify microorganism is high-level aminoglycoside sensitive
  • Baseline and surveillance hearing tests if planning more than 14 days of aminoglycoside
  • Frequent monitoring of creatinine for toxicity and/or dose adjustment
  • See Aminoglycoside Chapter for dosing/monitoring
  • Do not use tobramycin in place of gentamicin
• Ceftriaxone synergy
  • Can be used instead of gentamicin for synergy for ampicillin sensitive E. faecalis endocarditis (native or prosthetic)
  • Dosing is ceftriaxone 2 g IV q12h
• Rifampin
  • Used for staphylococcal prosthetic valve infections (either S. aureus or coagulase negative staphylococci)
  • Not initiated until cultures documented negative
  • Verify microorganism sensitivity to rifampin
  • Review medication list for drug-drug interactions
  • Monitor liver enzymes during therapy

Last reviewed January 2023

• At completion of therapy:
  • Prompt removal of PICC/vascular catheter
  • TTE (or TEE if poor windows or complex anatomy) to obtain new baseline valve function. Common for vegetation to remain visible, but persistent lesion is not a reason to extend antibiotic duration.
  • Early medical attention if unwell and obtain 3 sets of blood cultures if fever
• Patients with suspected or confirmed IE associated with drug use should be referred to Addiction Medicine for treatment.
• Maintain dental hygiene and administer antimicrobial prophylaxis prior to dental procedures that involve manipulation of gingival tissue or periapical region of teeth
• Oral regimens not recommended
  • May be an option on a case-by-case basis as method of harm reduction when long-term IV or central access is not feasible

Modified Duke Criteria:

Last reviewed January 2023

1. Baddour LM, et al. Infective endocarditis in adults: diagnosis, antimicrobial therapy, and management of complications: a scientific statement for healthcare professionals from the American Heart Association. Circulation. 2015;132: 1435-1486.

2. Sivak JA, et al. An Approach to Improve the Negative Predictive Value and Clinical Utility of Transthoracic Echocardiography in Suspected Native Valve Infective Endocarditis. J Am Soc Echocardiogr. 2016 Apr;29(4):315-22

3. Graupner C, et al. Periannular extension of infective endocarditis. J Am Coll Cardiol. 2002 Apr 3;39(7):1204-11.

4. Iversen K, et al. Partial Oral versus Intravenous Antibiotic Treatment of Endocarditis. N Engl J Med. 2019 Jan 31;380(5):415-424.

5. Baddour LM, et al. Infective Endocarditis in Adults: Diagnosis, Antimicrobial Therapy, and Management of Complications. Circulation. 2015;132:1435-1486.

Last reviewed January 2023