Infective Endocarditis

Question 1

most common bacteria?

Answer 1

• Strep. Viridans (most common)

- Staph. Aureus (2nd common)

Question 2

• any new murmur or change in existing murmur should raise suspicion of?.

Answer 2

endocarditis

Question 3

Diagnosis made using what criteria?

Answer 3

Modified Duke criteria

Require 2 major or 1 minor + 1 major criteria.

Question 4

Diagnosis using blood tests:

what is required with blood cultures?

rheumatoid factor?

Answer 4

Blood cultures: do three sets 12h apart, 90% diagnosed from 2 +ve sets.

Rheumatoid factor +ve.

Question 5

Tx of IE

• blind therapy?
• if penicillin allergic?
• Staphs + native valve:

Answer 5

• Blind therapy (native or prosthetic valve): ampicillin, flucloxacillin and gentamycin.

If penicillin allergic then give vancomycin + gentamycin.

flucloxacillin for >4 weeks. (if allergic then give vancomycin).

Question 6

A 39-year-old female intravenous drug user (IVDU) is admitted to the emergency department with shortness of breath. On examination, she has a temperature of 39.5ºC and is found to have Roth spots, Janeway lesions, and a new heart murmur.

Which of the following is most likely to be affected?

mitral valve
tricuspid valve
pulmonary valve
aortic valve

Answer 6

Infective endocarditis in intravenous drug users most commonly affects the tricuspid valve

Question 7

A 62 year old woman is admitted to the medical ward with a 3 week history of fevers and lethargy. On examination you note a few splinter haemorrhages in the finger nails and a loud systolic murmur at the apex. Your consultant instructs you to take 3 sets of blood cultures and to arrange an ECHO. Later that day you receive a call from microbiology about the provisional blood culture results.

Which of the following is most likely to have grown?

gram +ve cocci
gram +ve bacilli
gram -ve cocci
gram +ve bacilli

Answer 7

The vast majority of cases of bacterial endocarditis are caused by gram positive cocci.

Common causes:
Streptococcus viridans
Staphylococcus aureus (in intravenous drugs uses or prosthetic valves)
Staphylococcus epidermidis (in prosthetic valves)

Question 8

A 62-year-old female with a history of mitral regurgitation attends her dentist, who intends to perform dental polishing. She is known to be penicillin allergic. What prophylaxis against infective endocarditis should be given?

oral doxycycline
oral erythromycin
no Abx prophylaxis needed
oral clindamycin

Answer 8

no Abx prophylaxis needed

Antibiotic prohylaxis to prevent infective endocarditis is not routinely recommended in the UK for dental and other procedures