Infective Endocarditis Flashcards

1
Q

What is infective endocarditis?

A
  • Microbial infection of the heart valve or other endocardial tissue
  • Associated with an underlying cardiac defect
  • Fatal if left untreated
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2
Q

Increasing incidence of IE has been seen in

A
  • Elderly
  • Intravenous Drug Users
  • Patients with prosthetic heart valves
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3
Q

What are predisposing factors of IE?

A
  • Congenital heart disease accompanied by cyanosis
  • Rheumatic heart disease following rheumatic fever
  • Mitral valve prolapse with regurgitation
  • Degenerative valvular lesions; stenosis, regurgitation
  • Prosthestiv valves
  • IDU
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4
Q

PT is a 25-year-old male presenting with Fever, Cough, Shortness of
Breath, and Pleuritic Chest Pain. He has a III / IV Heart Murmur and Pulmonary Infiltrates on Chest X-Ray. He also has a history of Heroin Addiction for several years. His past medical history is non-contributory. Blood cultures are obtained in the Emergency Room and a TEE (Transesophageal Echocardiography) is scheduled. The patient is admitted for possible Infective Endocarditis.

The most likely Organism and affected Heart Valve in this patient are?
A. Viridians streptococci and Tricuspid Valve
B. Staphylococcus aureus and Tricuspid Valve
C. Viridians streptococci and Mitral Valve
D. Staphylococcus aureus and Mitral Valve
E. Pseudomonas aeruginosa and Tricuspid Valve

A

B. Staphylococcus aureus and Tricuspid Valve

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5
Q

Etiologic agents of infective endocarditis?

A
  • Streptococci (55-62% of cases)
  • Staphylococci (20-35%)
  • Enterococci (5-18%)
  • Gram-negative bacilli (1.5-13%)
  • Fungi (2-4%)
  • Miscellaneous (<5%)
  • Culture-negative (<5-24%)
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6
Q

Sequence of events leading to IE?

A
  1. Endothelial surface of the heart must be damaged
  2. Platelet and fibrin deposition occurs on the abdominal surface, forming a non-bacterial thrombotic endocarditis (NBTE)
  3. Bacteremia results in colonization of the endocardial surface
  4. Staphylococci, viridians streptococci, and enterococci are most likely to adhere to the non-bacterial thrombotic endocarditis probably because of production of specific adhere factors
  5. After colonization of the endothelial surface, fibrin, platelets, and bacteria continue to aggregate and a “vegetation” forms
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7
Q

What is the physiology of the heart-blood flow?

A
  1. The blood vessels that lead into the heart are the superior vena cava and the inferior vena cava - these vessels flow into the heart from the right atrium
  2. From the right atrium, deoxygenated blood passes through the tricuspid valve into the right ventricle
  3. From the right ventricle, blood passes into the pulmonary arteries which deliver it to the lungs where it can become oxygenated
  4. Following oxygenation, blood enters back into the heart at the left atrium
  5. From the left atrium, blood descends into the left ventricle by passing through the bicuspid (mitral) valve
  6. Oxygenated blood exits the left ventricle through the aortic valve where it can then travel out to the rest of the body
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8
Q

On a healthy heart, what can you expect to see?

A

No growths or vegetations

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9
Q

When you develop clots, what is the consistency?

A

The clots are gel-like in appearance due to fibrin and platelets

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10
Q

If left untreated, what can happen to vegetations in the heart?

A

The vegetations can continue to grow, developing into a valvular abscess and destroy the affected heart valves

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11
Q

If a patient has a valvular abscess, how do you treat it?

A

Surgery becomes necessary since antibiotics will have no effect

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12
Q

What are the heart valves involved in IE?

A
  1. Mitral (bicuspid) valve (86% of cases)
  2. Aortic valve (55% of cases)
  3. Tricuspid valve (20% of cases)
  4. Pulmonic Valve (1% of cases)
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13
Q

How many cases of IE are from the mitral valve and by which pathogen?

A

85% of causes are caused by Viridians streptococci when rheumatic heart disease is the underlying abnormality

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14
Q

How many cases of IE are from the aortic valve?

A

55% of cases, more involved in acute infections

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15
Q

How many cases of IE are from the tricuspid valve and by which pathogen?

A

20% of cases with the common site of involvement in staphylococcal endocarditis with intravenous drug use

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16
Q

Subacute

A

more indolent (slow growing) infection caused by less invasive organisms such as viridians streptococci and more recently CNS, usually occurring in a setting of prior valvular heart disease

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17
Q

Acute

A

Fulminant infection which most frequently follows infection of previously normal valves by virulent bacteria such as staphylococcus aureus, streptococcus pyogenes and streptococcus pneumoniae

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18
Q

Signs and symptoms caused by non-virulent organisms

A
  • Low grade fever
  • Malaise
  • Fatigue
  • Weight loss
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19
Q

Signs and symptoms caused by virulent organisms

A
  • High grade fever
  • Chills and sweats
  • Septic picture
  • Embolization complications
  • Heart murmur
  • Skin lesions
  • Other (renal failure, splenomegaly, back pain, abdominal pain, chest pain)
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20
Q

Peripheral manifestations of IE

A
  • Osler’s nodes
  • Roth spots
  • Janeway lesions
  • Splinter hemorrhages
  • Petechiae
  • Clubbing of the fingers
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21
Q

Osler’s nodes

A

-Purplish or Erythematous subcutaneous papules or nodules that may
appear on the palms of the fingers and toes
-2 – 15 mm in size; painful and tender
-Not specific for Infective Endocarditis, but may be the result of Embolic and / or Immunologic phenomena

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22
Q

Roth spots

A
  • Retinal Hemorrhages with white centers composed of coagulated fibrin
  • Usually caused by Immune Complex–mediated Vasculitis
  • Only visible with an Ophthalmic Exam
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23
Q

Janeway lesions

A

Hemorrhagic, painless plaques that may develop on the palms of the
hands or soles of the feet; believed to be Embolic in origin

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24
Q

Splinter hemorrhages

A

-Thin, linear Hemorrhages found under the nail beds of the
fingers or toes
-Not specific for Infective Endocarditis, and more commonly the result of Traumatic Injuries

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25
Q

Petechiae

A
  • Small (1–2 mm) Erythematous, Hemorrhagic lesions that are neither painful, nor tender.
  • May be anywhere, but are more evident on the Anterior Trunk, the Buccal Mucosa and Palate, and Conjunctivae
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26
Q

Clubbing of the fingers

A

Proliferative change in the soft tissues at the Terminal Phalanges that may be observed in chronic, long-standing Infective Endocarditis

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27
Q

Labs and other test findings in diagnosing IE

A
  • Blood cultures
  • Hematologic: WBC, BUN/SCr
  • ESR
  • Echocardiogram: TTE or TEE
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28
Q

TTE

A

Transthoracic

29
Q

TEE

A

Transesophageal

30
Q

Which 2D-echo is important in localizing valvular lesions when planning for surgeries

A

Transesophageal

31
Q

Which 2D-echo is more sensitive for detecting vegetations?

A

Transesophageal

32
Q

How do we make a confirmatory diagnosis of Infective Endocarditis?

A

The Duke Criteria has been developed to assist healthcare providers in diagnosing Infective Endocarditis. More specifically, the Duke Criteria helps to delineate between Major and Minor Diagnostic Criteria for Infective Endocarditis

33
Q

Major criteria for IE

A
  • Blood

- Echo

34
Q

How is blood a major criteria for IE?

A
Two blood cultures positive for organisms typically found in patients with
Infective Endocarditis (i.e., Viridians streptococci, Streptococcus bovis, a HACEK group organism, Staphylococcus aureus, or Enterococci in the absence of a primary focus)
35
Q

How is an echo a major criteria for IE?

A
  • Positive for IE
  • Myocardial abscess
  • Development of partial dehiscence of a prosthetic valve
  • New onset valvular regurgitation
36
Q

Minor criteria for IE

A
  • Predisposing heart condition for IDU
  • Fever >38C (100.4F)
  • Vascular phenomenon
  • Immunological phenomenon
  • Positive blood culture results not meeting major criteria
  • Echo results consistent with IE but not meeting major criteria
37
Q

Vascular phenomenon minor criteria example

A

major arterial emboli, septic pulmonary infarcts, intracranial hemorrhage, conjunctival hemorrhage, or Janeway lesions

38
Q

Immunological phenomenon minor criteria example

A

glomerulonephritis, osler noders, roth spots, and rheumatoid factor

39
Q

Endocarditis pathologic criteria diagnosis

A

microorganism by vegetation culture or intracardiac abscess confirmed by histology indicating active IE

40
Q

Endocarditis clinical criteria diagnosis

A
  • 2 major criteria OR
  • 1 major and 3 minor OR
  • 5 minor criteria
41
Q

Possible endocarditis diagnosis

A

findings consistent with IE but fall short of definite, but NOT rejected

42
Q

Rejected endocarditis diagnosis

A

Firm alternative diagnosis or resolution of symptoms in less than 4 days or no pathological evidence at surgery or autopsy

43
Q

Treatment guideline of IE

A
  • Firm diagnosis: presumptive therapy
  • Identify organisms, repeat blood cultures
  • Bactericidal antibiotics
  • Combination therapy often required
  • Duration of therapy is 4-6 weeks
  • Development of resistance is commonplace
  • Surgical intervention may be required
44
Q

IE empiric treatment of native valve

A
  • Vancomycin 15 mg/kg IV Q12H +/-

- Piperacillin/Tazobactam 4.5 gm Q6H

45
Q

IE empiric treatment of prosthetic valve

A
  • Vancomycin 15 mg/kg IV Q12H +
  • Gentamicin 1 mg/kg IV Q8H +
  • Rifampin 900 mg PO QD
46
Q

Monitoring parameters for Vancomycin

A

renal function and trough level

47
Q

Monitoring parameters for gentamicin

A

renal function and allergic reaction

48
Q

Monitoring parameters for Rifampin

A

liver functioning tests (ALT and AST)

49
Q

PT is a 25-year-old male presenting with Fever, Cough, Shortness of
Breath, and Pleuritic Chest Pain. He has a III / IV Heart Murmur and Pulmonary Infiltrates on Chest X-Ray. He also has a history of Heroin Addiction for several years. His past medical history is non-contributory. Blood cultures are obtained in the Emergency Room and a TEE (Transesophageal Echocardiography) is scheduled. The patient is admitted for possible Infective Endocarditis

The most appropriate empiric regimen, based on the most likely offending Pathogen, should include:

A. Aqueous Crystalline Penicillin G, 24 mU / day plus Gentamicin 1 mg / kg IV, q8h
B. Vancomycin, 1 g IV, q12h
C. Vancomycin, 1 g IV, q12h plus Gentamicin, 1 mg / kg IV, q8h
D. Ampicillin 2 g IV, q4h plus Gentamicin, 1 mg / kg IV, q8h
E. Vancomycin 1 g IV, q12h plus Gentamicin 1 mg / kg IV, q8h plus
Rifampin, 300 mg PO q8h

A

B. Vancomycin, 1 g IV, q12h

50
Q

Treatment of viridians streptococci / streptococcus bovis IE if PCN susceptible

A

PCN G 12-18 mU/d IV x 4 weeks

51
Q

Treatment of viridians streptococci / streptococcus bovis IE if PCN intermediate

A

PCN G 24 mU/d x 4weeks + Gent 3 mg/kg q24H x 2 weeks

52
Q

Treatment of viridians streptococci / streptococcus bovis IE if PCN allergic

A
  • Ceftriaxone 2 g IV QD x 4 weeks OR

- Vancomycin 15 mg/kg IV q12H x 4 weeks

53
Q

Treatment of enterococci or Penicillin-resistant viridians streptococci IE first line therapies

A
  • PCN G 18-30 mU/d IV + Gent 1 mg/kg IV q8H x 4-6 wks (Strep)
  • Ampicillin 2 g IV q4H + Gent 1 mg/kg Q8H x 4-6 weeks (enterococci)
54
Q

Treatment of enterococci or Penicillin-resistant viridians streptococci IE if PCN-allergic pts or PCN-R enterococci?

A

Vancomycin 15 mg/kg IV q12H + Gent 1 mg/kg q8H x 6 weeks

55
Q

Treatment of enterococci or Penicillin-resistant viridians streptococci IE if high level aminoglycoside resistance?

A

Amp 2 g IV q4H + Ceftriaxone 2 g IV q12H for 6 weeks

56
Q

Treatment for Staphylococci with absence of prosthetic valve methicillin susceptible?

A

Nafcillin 2 g IV q4H x 6 weeks

57
Q

Treatment for Staphylococci with absence of prosthetic valve methicillin resistant or PCN allergy?

A

Vancomycin 15 mg/kg IV q12H x 6 weeks

58
Q

Treatment for Staphylococci with presence of prosthetic valve methicillin susceptible?

A
  • Nafcillin 2 g IV q4H x 6 wks +
  • Rifampin 300 mg PO q8H x 6 weeks +
  • Gent 1 mg/kg q8H x 2 weeks
59
Q

Treatment for Staphylococci with presence of prosthetic valve methicillin resistant?

A
  • Vancomycin 12 mg/kg IV q12H x 6 wks +
  • -Rifampin 300 mg PO q8H x 6 weeks +
  • Gent 1 mg/kg q8H x 2 weeks
60
Q

Consider prophylaxis against IE in patients with:

A

High risk conditions AND high risk procedures

61
Q

High risk conditions

A
  • Presence of prosthetic heart valve
  • History of endocarditis
  • Cardiac transplant recipients who develop cardiac valvulopathy
  • Congenital heart disease with a high pressure gradient lesion
62
Q

High risk procedures

A
  • Any procedure involving manipulation of gingival tissue or the periapical region of the teeth or perforation of the oral mucosal
  • Any procedure involving incision in the respiratory mucosa
  • Procedures on infected skin or musculoskeletal tissue including incision and drainage of an abscess
  • Prophylaxis is no longer routinely recommended for gastrointestinal or genitourinary procedures
63
Q

Procedures that do NOT need prophylaxis

A
  • Routine Anesthetic Injections through non-infected tissue
  • Taking Dental Radiographs
  • Placement of removable Prosthodontic (or Orthodontic) appliances
  • Adjustment of Orthodontic Appliances
  • Placement of Orthodontic Brackets
  • Shedding of Deciduous Teeth
  • Bleeding from Trauma to the Lips or Oral Mucosa
64
Q

Regimens for dental procedures (oral)

A

Amoxicillin 2 g in adults OR 50 mg/kg in children

65
Q

Regimens for dental procedures unable to take oral medication

A
  • Ampicillin 2 g IM or IV in adults or 50 mg/kg in children

- Cefazolin 1 g IM or IV in adults or 50 mg/kg in children

66
Q

Regimens for dental procedures allergic to PCN or Ampicillin

A
  • Cephalexin 2 g in adults or 50 mg/kg in children

- Clindamycin 600 mg in adults or 20 mg/kg in children

67
Q

Regimens for dental procedures allergic to PCN or Ampicillin AND unable to take oral medication

A
  • Cefazolin 1 g IM or IV in adults or 50 mg/kg in children

- Clindamycin 600 mg in adults or 20 mg/kg in children

68
Q

PT, a 27-year-old female status post-mitral valve replacement 2 weeks
ago, is re-admitted to the hospital after being home for only a week. The patient is febrile, blood cultures are positive (organism identification and antibiotic sensitivities are pending) and there is a systolic murmur heard (III / IV). A preliminary diagnosis of Prosthetic Valve Endocarditis is made

Recommend an appropriate Empiric Regimen, including drug(s), and dosing regimen.

A

Vancomycin, 15 mg / kg IV, q12h + Gentamicin, 1 mg / kg IV, q8h + Rifampin, 900 mg PO daily; g

69
Q

PT, a 27-year-old female status post-mitral valve replacement 2 weeks
ago, is re-admitted to the hospital after being home for only a week. The patient is febrile, blood cultures are positive (organism identification and antibiotic sensitivities are pending) and there is a systolic murmur heard (III / IV). A preliminary diagnosis of Prosthetic Valve Endocarditis is made

PT was successfully treated thanks to your therapy recommendations. She
is scheduled for wisdom teeth extractions in 2 weeks

What would be an appropriate recommendation regarding Endocarditis
Prophylaxis for PT, based on the guidelines from the American Heart Association (AHA)?

A

Amoxicillin, 2 g PO, 30 – 60 minutes prior to the procedure, given that
she CAN take oral medication and does NOT have a Penicillin / Ampicillin allergy