Transcript Infective Endocarditis Prophylaxis….. Where are we now?

Extraoral infections caused
by oral bacteria
Endocarditis
Infective endocarditis
Infection of endocardium
acute
 subacute
 chronic

About 2 to 3 out of 100,000 people develop bacterial
endocarditis each year in the US
Risk factors
Defective valves
 Prosthetic valves
 Congenital heart defects e.g.

 Ventricular
septal defect
 Patent ductus arteriosus
Causative organisms

Viridans streptococci (50%)
(S. mutans, S. sanguis)

Staphylococcus aureus
Enterococcus faecalis
 More uncommonly other bacteria, fungi

Pathogenicity
Bacteremia
 Biofilm along valve edges

 Infectious
organisms
 Mass of fibrin
 Platelets
Clinical Features

Valve destruction  heart failure

Embolic events

Immune complex deposition  vasculitis
 arthralgia
 glomerulonephritis

Malaise, fever, night sweats, weight loss, anaemia
 abscesses in brain, liver
Diagnosis
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Blood cultures – repeated samples
Anaemia
 white blood cell count
 erythrocyte sedimentation rate
Echocardiography
Mortality

Fatal if untreated
6% sensitive streptococci
 30% Staphylococcus aureus

Management

Antibiotics i.v.
(penicillin and gentamicin before AST results)

Oral antibiotics
Bacteremia
Frequency of bacteremia
Procedure
Extraction
%
10-100
Scaling and root planing
8-80
Rubber dam matrix/wedge
placement
9-32
Tooth brushing and
flossing
Chewing food
20-68
7-51
Magnitude of bacteremia
Dental procedures
<104 CFU/ml
Routine daily activities
<104 CFU/ml
Experimental endocarditis
106 – 108 CFU/ml
Persistance of bacteremia

Most positive blood cultures were within
10 mins after extraction.

6-30 minutes with single extraction

Only a small no. of positive blood cultures
between 30-60 minutes
Control and prevention
Oral hygiene
 Antibiotics

Dental procedures


All dental procedures that involve manipulation
of gingival tissue or the periapical region of teeth
or perforation of the oral mucosa,
e.g.

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Extraction
Periodontal probing, scaling, root planing and surgery
Biopsy
Suture removal
Subgingival restorations
Orthodontic band placement
ATB

One hour pre-operation

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Amoxycillin
If penicillin allergic, clindamycin 600mg po
Allergic to penicillin and unable to swallow
capsules, azithromycin 500mg po

Alternatively intravenous options
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Pre-operative chlorhexidine (0.2%) mouthrinse
Amoxycillin

Drug of 1st choice

Well absorbed from GIT

High serum concentrations

Few side-effects

BUT increasing resistance to penicillin
in viridans streptococci
Adverse reactions

Check for drug allergy

Check for antibiotic treatment in last 4 weeks

If patient is on other drugs, antibiotics may interfere
with.