Endocarditis

Question 1

1. Describe the different types of endocarditis.

Answer 1

often named based on responsible organisms OR

Acute bacterial endocarditis ABE
subacute bacterial endocarditis SBE

can be associated with route of infection: prosthetic valve, health care associated, community associated, injection drug use, pacemaker associated or culture negative

Question 2

2. Name the common organisms that cause the different types of endocarditis.

Answer 2

Strep: viridans, bovis, pneumonia (SBE) or other group B or A

Enterococci (SBE)

Staph aureus (ABE, PVE, healthcare associate and IV use)

coagulase-negative staphylococci (PVE, pacemaker, community acquired) except uncharacteristic S. lugdunesis

gram negative bacilli (high mortality) ie. enterbacteriaceae, salmonella, klebsiella, Pseudomonas aeruginosa

HACEK: Haemophilus, Actinobacillus, Cardiobacterium, Eikenalla, Kingella

Fungi

OVERALL, S. AUREUS most common in patients

Question 3

3. Describe the portal of entry, risk factors and pathophysiologic sequelae of endocarditis.

Answer 3

predisposing cardiac condition or alteration to valve surface including deposition sterile vegetation (not required for acute process with virulent bug)

transient bacteremia- via portals: dental work or disrepair, UTI, colon cancer, skin infection or IV catheters

strep and staph aggregate platelets (form vegetation) and bacterial shedding from vegetation occurs

activation of humoral and cellular immune system can cause cardiac complications, embolic complications (Janeway lesions, Splinter hemorrhages, Roth spots) and bacteremic complications, immunologic complications (Osler’s nodes)

Question 4

4. Describe the common clinical presentations and pathophysiologic sequelae of endcarditis.

Answer 4

presentation is highly varied, often subtle and can present similar to other disease

SBE: indolent, low fever, weight loss, malaise, anorexia, heart murmur common, peripheral signs (splinter hemorrhages, petechiae, osier’s nodes, Janeway lesions (palms), Roth spots (retinal)), splenomegaly, athralgia, myalgia, major emboli, mycotic aneurysms

ABE: fulminant, high fever, severe heart failure, acute valve destruction, toxic appearance, less likely to have audible murmur, embolic complications or immunologic complications or peripheral signs

Question 5

5. Describe the key features that allow the diagnosis of endocarditis to be made.

Answer 5

obtaining blood cultures when the dx. of endocarditis is considered is essential (3 sets), anemia and high sed. rate may be clues

immunologic test are often abnormal, EKG can show arrhythmia

ECHO-used to detect vegetations is critical, specifically transesophageal

Duke criteria was helpful in language around diagnosis criteria

Question 6

6. Describe the concepts that underlie the management of endocarditis.

Answer 6

antibiotic regimens must be bactericidal and given in a high dose for prolonged periods of time usually 4-6 weeks of IV therapy

determine antimicrobial susceptibility using MIC data

initial phase should take place in acute care hospital setting with a cardiac surgeon available for ABE and PVE and daily monitoring

Question 7

6. Describe the concepts that underlie the prevention of endocarditis.

Answer 7

antibiotic prophylaxis in accordance with guidelines in high risk cardiac conditions (prosthetic valve, PREVIOUS IE, congenital heart problems etc.– deformities of valves or chambers)

Question 8

Bonus: List organisms associated with specific types of endocarditis (based on route of infection).

Answer 8

prosthetic valve: EARLY-coagulase negative staph, S. aureus, GNR or enterococci, cadida LATE-viridans strep, coagulase neg. staph, enterococci, S. aureus

pacemaker: S. sure us and coagulase neg.

Healthcare associated: S. aureus, coaguative negative, Candida

Injection drug use: S. aureus, Pseudomonas aeruginosa, Candida

Culture negative: due to sample post antibiotics, fastidious organisms, or rare org: fugi, legionella, mycoplasma, rickettsia or chlamydia