Infective Endocarditis study notes

Question 1

What are HACEK organisms

Answer 1

A group of gram negative fastidious bacilli that require prolonged culture in 10% CO2
Haemophilus species (not influenza) 
Actinobacillus
Cardiobacterium hominis
Eikenella corrodens
Kingella

Question 2

What are commonest organisms in patients with native valve infective endocarditis

Answer 2

Streptococcus (45%) Viridans (including milleri, oralis, mitis, mutans, salivarius) or bovis
Staphylococcus aureus or epidermidis (35%)
Enterococcus Faecalis (10%)
Diptheroid bacillis and micro-aerophilic streptococci
HACEK
Anaerobic gram negative bacilli
Listeria, Bacteroides, fusobacterium, Legionella, Propionibacterium acnes, brucella abortus
Coxiella Burnetii (Q fever)
Chlamydia psittaci or trachomatis
Fungal
Candida
Aspergillus
Histoplasma

Question 3

What are commonest organisms in patients with prosthetic valve infective endocarditis < 2months

Answer 3

Staphylococcus aureus and epidermidis (45-50%)
Gram negative bacilli
Fungi
Streptococcus and Entercoccus (<10%)

Question 4

What are commonest organsims of prosthetic IE > 2months

Answer 4

Streptococcus viridans (45%)
Staphyloccus aureus and epidermidis (35%)
Enterococcus faecalis (10%)

Question 5

What are causes of non-infective endocarditis

Answer 5

Anti-phospholipid syndrome (Hughes syndrome)
Acute rheumatic fever (Lancefield group A Streptococcus)
Libman-sacks endocarditis (SLE and scleroderma)
Mucinous adenocarcinoma (pancrease, lung, GI tract)
Other malignant disease–lymphoma, bladder CA

Question 6

What are Dukes Minor criteria

Answer 6

Predisposing factors (IV drug use, cardiac lesion)
Fever > 38 degree C
Embolic or vascular phenomena
Immunological phenomena
Serology consistent with IE
Blood cultures compatable but not typical of IE

Question 7

What are major criteria for Dukes Classification

Answer 7

1) Three positive Blood cultures (12 hours apart)
showing typical organisms (Strep bovis or viridans, Staph aureus, entercocci, or HACEK
2) Evidence of endocardial infection
vegetation, abscess, prosthetic valve dehiscence , new regurgitation

Question 8

What is significance of Dukes Criteria

Answer 8

Definite endocarditis (Specificity 99% and sensitivity 80%)

Clinical diagnosis

1) 2 major criteria
2) 1 major and 3 minor criteria
3) five minor criteria
4) pathological diganosis by histological evidence of active infective endocarditis (post op specimen).

Question 9

Graft selection for aortic root replacement in complex active endocarditis

Answer 9

UPenn from 2000 to 2010 in 134 patients

32.1 +/- 29.4 months follow up and showed 5 year survival rates betweem mechanical, bioprosthetic, and homograft of similar results (58% each)

Question 10

What is rate of prosthetic valve endocarditis

Answer 10

0.5 to 1% per year following valve surgery

Question 11

What valve are most likely to be infected

Answer 11

Left sided valves (mitral is more common then aortic)

5% involving the tricuspid and very rare for pulmonary

Question 12

What is brief pathophysiology of infective endocarditis

Answer 12

platelet-fibrin thrombus formation with subsequent bacterial colonisation resulting in vegetation formation and spread into the surronding tissues

Question 13

What is Roth spot

Answer 13

Retinal boat-shaped hemoorage with a pale center

Question 14

What are splinter hemorrhages

Answer 14

thin reddish-brown lines in the nail bed

Question 15

What are Osler’s nodes

Answer 15

painful pulp infarcts on fingers, toes, palms or soles

Question 16

What are Janeway lesions

Answer 16

painless flat palmar and plantar erythema

Question 17

What are most common organisms in early PVIE

Answer 17

Staph aureus and Stah epi (50%)
Gram negative
Fungi
Strep and Enterococcus (< 10%)

Question 18

What antibiotics should be used for the common organisms in IE

Answer 18

Penicillin and gentamicin can be started
if you suspect stap then you need to start vanco
If enterococcus start amoxycillin and gentamicin

Question 19

What is suggested treatment for HACEK

Answer 19

Start ceftriaxone

usually beta-lactam resistant

Question 20

What are causes of non-infective (marantic) IE

Answer 20

musconous adenocarciumoa (pancreas, lung, upper GI tract)
other malignant disease –lymphoma, bladder carcinomoa
Anti-phospodlipid syndrome (hughes syndrome)
Acute rheumatic fever (GAP strep)
Libman-sacks endocarditis (SLE)

Question 21

What is significance of Dukes Criteria

Answer 21

Specificitiy 99%

Sensitivity 80%

Question 22

What are empiric antiobiotic treatments for acute IE

Answer 22

Empiric antibiotic therapy is chosen based on the most likely infecting organisms.

Native valve endocarditis (NVE) has often been treated with penicillin G and gentamicin for synergistic coverage of streptococci.

Question 23

List coverage for IV drug users

Answer 23

Have been treated with nafcillin and gentamicin to cover for methicillin-sensitive staphylococci.

emergence of methicillin-resistant S aureus (MRSA) and penicillin-resistant streptococci has led to a change in empiric treatment with liberal substitution of vancomycin in lieu of a penicillin antibiotic

Question 24

What is treatment regimen for prosthetic IE

Answer 24

Prosthetic valve endocarditis (PVE) may be caused by MRSA or coagulase-negative staphylococci (CoNS)
thus, vancomycin and gentamicin may be used for treatment, despite the risk of renal insufficiency.
Rifampin is necessary in treating individuals with infection of prosthetic valves or other foreign bodies because it can penetrate the biofilm of most of the pathogens that infect these devices.

Question 25

What is dose of pen g

Answer 25

Endocarditis: 12-20 million units/day IV divided q4-6hr x4-6 weeks

Question 26

What are rates of recurrence post IE

Answer 26

“Recurrence rates are approximately 5% to 12%.”

Question 27

What are clinical features of infective endocarditis

Answer 27

Clinical features of infection: fever, night sweats, rigors, weight loss, malaise,
Immune complex depositions are:
Roth spots–retinal boat shaped hemorrhage with a pale center
Splinter hemorrhages–thin reddish-brown lines in the nail bed
Oslers Nodes—painful pulp infarcts on the fingers, toes, palms and soles
Janeway lesions–painless flat palmar or plantar erythema
vassulitis (brain, skin, kidney) and arthalgia
clinical features of cardiac lesion
clinical features of emboli