Endocarditis - Low/Med Priority

Question 1

Describe basic anatomy of the heart.

Answer 1

4 valves:
-tricuspid, mitral, aortic, pulmonary
direction of blood flow through valves is forward
opening and closing of valves is controlled by BP in each chamber

Question 2

What is endocarditis?

Answer 2

inflammation of endocardium (inner layer of the heart) usually involving the valves
-based on source of inflammation, endocarditis is classified into IE or non-IE

Question 3

What are vegetations?

Answer 3

abnormal growth often associated with endocarditis
-composed of fibrin clots, platelets, and microorganisms
-endocarditis lesions are known as vegetations

Question 4

Describe the pathogenesis of endocarditis.

Answer 4

endothelial damage –> deposition of platelets and fibrin –> bacterial adherence & colonization –> enlarged and inflamed vegetation –> IE

Question 5

Describe the clinical presentation of endocarditis.

Answer 5

fever
malaise, general fatigue
NV, anorexia
night sweats
weight loss
dyspnea, pleuritic chest pain
headache, abdominal/back pain
sepsis
acute HF
cardiac murmur
physical stigmata: splinter hemorrhages, Janeway lesions, Osler nodes, petechiae, pulmonary edema, splenomegaly, etc

Question 6

What are the complications of endocarditis?

Answer 6

embolic:
-systemic embolization most common in left-sided IE
-pulmonary embolism in right-sided lesions
-causing stroke, paralysis, blindness, MI, ischemia
immunologic:
-glomerulonephritis, Roth spots, Osler nodes
cardiac:
-valvular destruction leading to HF
-perivalvular and metastatic abscesses
-conduction abnormalities and heart block
infectious:
-vertebral osteomyelitis and septic arthritis
-meningitis
-pulmonary infections

Question 7

What are the risk factors for endocarditis?

Answer 7

male sex
age > 60 yrs
PWID
structural heart disease
poor dentition/dental infections

Question 8

What are the 3 most common organisms causing IE?

Answer 8

staphylococci (40%):
-common cause of health-care associated IE
-S. aureus most common cause of IE in the world and PWID
streptococci (20%):
-common cause of community-acquired native valve IE
-likely source is odontogenic
enterococci (10%):
-may be seen in pts with hx of GU/obstetric procedures or GI malignancy

Question 9

What is the gold standard for diagnosis of IE?

Answer 9

modified Duke criteria

Question 10

What are the goals of therapy for IE?

Answer 10

cure the infection
relieve signs and symptoms
decrease morbidity and mortality associated with the infection
prevent further damage to valves and CV system
prevent recurrence of IE
educate on IE prophylaxis based on procedure

Question 11

What is indicated for life-threatening cases of HF secondary to valve damage due to IE?

Answer 11

surgical measures

Question 12

What should be done prior to antimicrobial therapy?

Answer 12

obtain blood cultures and use susceptibility data to guide targeted therapy

Question 13

When does the duration of therapy start for IE?

Answer 13

1st day of negative blood cultures

Question 14

What does the duration of therapy depend upon for IE?

Answer 14

isolated pathogen
patient factors
location and severity

Question 15

What does the choice of antibiotic depend upon for IE?

Answer 15

pt risk factors (e.g. PWID, GU procedure)
adherence to regimen
left vs right sided
native vs prosthetic valve
pathogen culture, susceptibility and resistance

Question 16

By which route of administration should we treat IE?

Answer 16

IV

Question 17

How is native valve IE caused by Staphylococci treated?

Answer 17

MSSA:
-cloxacillin or cefazolin
-6 weeks (left sided) or 2 weeks (right sided)
MRSA:
-vancomycin x 6 weeks
MRSA or MSSA:
-daptomycin x 6 weeks

Question 18

How is prosthetic valve IE caused by Staphylococci treated?

Answer 18

MSSA:
-6 weeks of beta-lactam + rifampin + 2 weeks of gentamicin
MRSA:
-6 weeks of vancomycin + rifampin +2 weeks of gentamicin
MRSA or MSSA:
-6 weeks of daptomycin + rifampin

Question 19

How is native valve IE caused by Viridans group Streptococci or S. bovis/gallolyticus that is penicillin-susceptible treated?

Answer 19

MIC < 0.12 mcg/ml
penicillin G x 4 wks
ceftriaxone x 4 weeks
BL allergy: vancomycin x 4 wks (target trough 10-15)
short course: pen G or ceftriaxone + gentamicin

Question 20

How is native valve IE caused by Viridans group Streptococci or S. bovis/gallolyticus that is relatively penicillin-resistant treated?

Answer 20

MIC > 0.12 mcg/ml to < 0.5 mcg/ml
pen G x 4 wks + gentamicin once daily x 2 wks
if isolate if ceftriaxone susceptible, then ceftriaxone alone may be sufficient
BL allergy: vancomycin x 4 wks

Question 21

How is native valve IE caused by Viridans group Streptococci or S. bovis/gallolyticus that is penicillin-resistant treated?

Answer 21

MIC > 0.5 mcg/ml
ampicillin or pencillin + gentamicin x 4-6 wks
ceftriaxone + gentamicin is reasonable if susceptible to ceftriaxone x 4-6 wks
BL allergy: vancomycin x 4-6 wks

Question 22

How is prosthetic valve IE caused by Viridans group Streptococci or S. bovis/gallolyticus treated?

Answer 22

pencillin susceptible (MIC < 0.12 mcg/ml):
-pen G or ceftriaxone x 6 wks +/- gentamicin x 2 wks
-BL allergy: vancomycin x 6 wks

penicillin resistance (MIC > 0.12 mcg/ml):
-pen G or ceftriaxone + gentamicin x 6 wks
-BL allergy: vancomycin x 6 wks

Question 23

How is IE caused by Enterococci treated?

Answer 23

pen G/ampicillin + gentamicin x 4-6 wks
ampicillin + ceftriaxone x 6 wks
-preferred for CrCl < 50 ml/min

Question 24

Which organism are we covering for with IE antibiotic prophylaxis?

Answer 24

Viridans group Strep

Question 25

Which patients should receive IE antibiotic prophylaxis?

Answer 25

only high-risk individuals undergoing select dental, GI, GU procedures -prosthetic cardiac valve or prosthetic material -previous IE -unrepaired cyanotic congenital heart disease -repaired CHD with residual shunts or valvular regurigation -cardiac transplant recipients with valve regurgitation

Question 26

Which procedures require IE antibiotic prophylaxis?

Answer 26

dental: manipulation of gingival tissue or perforation of mucosa respiratory: incision or biopsy of mucosa infected skin, skin structures, or MSK tissue

Question 27

What are the options for IE antibiotic prophylaxis?

Answer 27

amoxicillin -2g po or 50 mg/kg for child pts who cannot take medication orally -ampicillin or cefazolin/ceftriaxone penicillin allergy -cephalexin 2 g po (non-severe, non-type 1) -clindamycin 600 mg po -azithro 500 mg po or clarithro 500 mg po -cefazolin or ceftriaxone

Question 28

How are antibiotics administered for IE prophylaxis?

Answer 28

30-60 min prior to procedure

Question 29

What should be done if IE antibiotic prophylaxis is missed before a procedure?

Answer 29

it can be given up to 2 hrs after the procedure