Subacute Bacterial Endocarditis

Question 1

Define subacute endocarditis

Answer 1

Inflammation of the endocardium caused by an infection localised on cardiac valves

Question 2

Valves commonly effected by SBE

Answer 2

Mitral and aortic valves

Question 3

Name 5 risk factors for SBE

Answer 3

Valvular HD with stenosis or regurgitation 
Valve replacement 
Previous case of SBE
Structural congenital heart disease 
Hypertrophic cardiomyopathy

Question 4

Name 5 symptoms associated with SBE

Answer 4

Fatigue 
Vomiting 
Low-grade fever 
Loss of appetite 
Pleuritic pain 
Abdominal pain
Back pain 
Congestive heart failure

Question 5

Name 3 dermatological signs of SBE

Answer 5

Splinter heamorrhages
Janeway lesions
Oslers nodes

Question 6

Name 3 causative organisms of SBE

Answer 6

Staphylococcus aureus 
Streptococcus viridans
Streptococcus intermedius 
Pseudomonas aeruginosa 
Group A, C, D and G streptococci

Question 7

In SBE, what would be expected from the blood results

Answer 7

Increased CRP or ESR
Leukocytosis
Anaemia
Micro haematuria

Question 8

Would could be found in an echogram of a valve effected with SBE

Answer 8

Vegetation
Abscess
Dehiscences of prosthetic valve

Question 9

Which IV antibiotics are used in

1. Asymptomatic SBE
2. Symptomatic SBE
3. Severe sepsis

Answer 9

1. Amoxicillin (and Gentamicin)
2. Vancomycin + Gentamicin
3. Vancomycin + Meropenem

Question 10

Describe Meropenem and its mechanism

Answer 10

Spectrum: broad 
Type: carbapenem beta-lactame 
Organism: gram- positive and gram-negative bacteria 
Action: inhibit cell wall synthesis
Result: bactericidal

Question 11

Describe Vancomycin and its mechanism

Answer 11

Spectrum: narrow 
Type: glycopeptide antibiotic
Organism: aerobic and anaerobic gram-positive bacteria
Action: inhibit cell wall synthesis
Result: bacteriostatic

Question 12

Describe Gentamicin and its mechanism

Answer 12

Spectrum: broad
Type: aminoglycoside antibiotic
Organism: primarily aerobic gram-negative bacteria; 2nd gram-positive bacteria
Action: inhibits synthesis of proteins vital for cell growth
Result: bacteriostatic

Question 13

Describe Amoxicillin and its mechanism

Answer 13

Spectrum: narrow  
Type: penicillin beta-lactate   
Organism: wide range of gram-positive bacteria; limited range of gram-negative bacteria 
Action: inhibits cell wall synthesis 
Result: bactericidal