9. MTB Step 3 - Infective Endocarditis

Question 1

DUKE CRITERIA

Describe the Duke Criteria for Infective Endocarditis diagnosis.

Answer 1

2 Major, 1 Major and 3 Minor, or 5 Minor criteria:

Major Criteria:

1. Two positive Blood Cultures
2. Abnormal Echocardiogram

Minor Criteria:

1. Fever (> 100.4)
2. Presence of Risk Factors
3. Vascular Findings
4. Immunological Findings
5. Microbiological Findings

Question 2

DUKE CRITERIA

What constitutes the (2) Major Duke Criteria for IE diagnosis?

Answer 2

1. Two positive Blood Cultures with:
   
   • Staphylococcus aureus
   • Viridans streptococci, Streptococcus bovis/epidermis**, enterococci, gram-negative rods,**Candida
   • HACEK organisms are generally culture negative (Haemophilus aphrophilus/parainfluenza, Actinobacillus actinomycetmcomitans, Cardiobacterium hominis, Eikenella corrodens, Kingella kingae.
2. Abnormal Echocardiogram (one of the following):
   
   • Intracardiac Mass or Valvular Vegetation
   • Abscess
   • New partial dehiscence of prosthetic valve

Question 3

DUKE CRITERIA FOR ENDOCARDITIS

MANAGEMENT

What constitutes the (5) Minor Duke Criteria for IE diagnosis?

Answer 3

1. Fever (> 38.0°C [> 100.4°F])
2. Presence of Risk Factors:
   
   • IVDU
   • Structural Heart Disease
   • Prosthetic Heart Valve
   • Dental procedures involving Bleeding
   • History of Endocarditis
3. ​​Vascular Findings:
   
   • ​​​Janeway Lesions
   • Septic Pulmonary Infarcts
   • Arterial Emboli
   • Mycotic Aneurysm
   • Conjunctival Hemorrhage
4. ​​Immunological Findings:
   
   • ​​​Roth Spots
   • Osler Nodes
   • Glomerulonephritis
5. ​​Microbiologic Findings:
   
   • ​​​Positive Blood Culture OTHER than those meeting Major Criteria.

Question 4

DUKE CRITERIA FOR ENDOCARDITIS

MANAGEMENT

1. What is the Best NEXT Step in Management for a patient who presents with a FEVER + NEW MURMUR or CHANGE IN MURMUR?
2. If the Test in #1 is Positive, what is the Best NEXT Test, and what is it Looking For?

Answer 4

1. Blood Cultures
2. Echocardiogram - to look for Vegetations
   
   • First do TTE (Sens = 60%, Spec = 90-95%)
   • If TTE is negative, then TEE (Sens = 90-95%, Spec = 90-95%)

Question 5

ETIOLOGY

What are the (2) Most Common Causes of Culture-Negative Infective Endocarditis?

Answer 5

1. Coxiella
2. Bartonella

These two account for 80% of Culture-Negative Endocarditis

NOT the HACEK** **groud of organisms.

Question 6

DIAGNOSIS

1. Which Culture-Negative cause of Endocarditis is Most Frequently associated with Colonic Pathology?
2. What Additional Exam should be performed if the test is Positive for this Organism?
3. What other organism should you perform this additional test for if positive?

Answer 6

1. Clostridium septicum (even though Streptococcus bovis is associated with colonic pathology, C. septicum is MOST FREQUENTLY associated with colonic pathology)
2. Colonoscopy
3. Streptococcus bovis

Question 7

TREATMENT

1. What is the Best EMPIRIC Combination Therapy for IE?
2. What is (1) Antibiotic that may be substituted for one of the other antibiotics in this Combination Therapy and for which Organism is this substitution allowed?
3. Which (2) Organisms (Hint: Most Common Causes of IE) does this Empiric Therapy cover?

Answer 7

1. Vancomycin + Gentamicin (or Ceftriaxone) for 4 - 6 weeks
2. Daptomycin is an alternative to Vancomycin in MRSA Endocarditis
3. Two Most Common IE Organisms:
   
   • Staph. aureus (MSSA & MRSA)
   • Strep. viridans

Question 8

TREATMENT

What are the (5) Anatomic Defects considered the Strongest Indications for Surgery (Valve Replacement) in patients with Infective Endocarditis, that are Hard or Impossible to correct with antibiotics alone?

Answer 8

1. Valve Rupture
2. Abscess
3. Prosthetic Valves
4. Fungal Endocarditis
5. Embolic Events once already started on antibiotics

Question 9

PROPHYLAXIS

Which (4) CARDIAC DEFECTS are the ONLY defects that need Infective Endocarditis Prophylaxis?

Answer 9

1. Prosthetic Valves
2. Unrepaired Cyanotic Heart Disease
3. Previous Endocarditis
4. Transplant Recipients who develop Valve Disease

Question 10

PROPHYLAXIS

Which (3) MEDICAL PROCEDURES are the ONLY procedures that need Infectious Endocarditis Prophylaxis?

Answer 10

1. Dental Procedures that cause BLEEDING
2. Respiratory Tract Surgery
3. Surgery of Infected Skin

Question 11

PROPHYLAXIS

What is the Infectious Endocarditis Prophylactic Antibiotic Drug of Choice (DOC) for DENTAL Procedures that cause Bleeding?

Answer 11

Amoxicillin

• Penicillin-allergy = RASH*
• Cephalexin
• Penicillin-allergy = ANAPHYLAXIS*
• Azithromycin
• Clarithromycin
• Clindamycin
• Penicillin-allergy = UNKNOWN REACTION*
• Clindamycin

Question 12

PROPHYLAXIS

What is the Infectious Endocarditis Prophylactic Antibiotic Drug of Choice (DOC) for SKIN Procedures?

Answer 12

Cephalexin

• Penicillin Allergy = UNKNOWN*
• Vancomycin