Endocarditis Flashcards
What is endocarditis?
Infection of the lining of the heart and cusps of the cardiac valves
What causes endocarditis?
Bacteria adhering to and multiplying on the innermost chamber of the heart and its valves.
Predominantly effects left side of heart
What are the risk factors for developing endocarditis?
Congenital valve disease Degenerative valve disease Rheumatic heart disease Mitral thrombus IV drug abuse Valvular/cardio surgery Central venous lines Elderly
What is the pathophysiology of endocarditis?
A healthy heart lining is resistant to bacteria in the blood. If there is an endothelial injury, cytokines are recruited to the area. Bacteria enters blood through vigorous teeth brushing which aggregates and forms clots, and a surface for other bacteria to bind to, which leads to an infection which is hard to penetrate with antibiotics
What are early symptoms of bacterial endocarditis?
Early manifestation: - Low grade fever - Fatigue - Heart murmur - Malaise Embolic events - e.g. stroke
Consider infective endocarditis in which patients?
Those with:
New prosthetic valve insertion
Embolic event of unknown origin
Sepsis of unknown origin
Heamaturia (unknown reason)
How does a later presentation of endocarditis present itself?
- Splinter haemorrhages (damage to capillaries associated with micro emboli forming in nail bed)
- Roth’s spots (micro emboli that form in the retina of the eye)
- Osler’s Nodes (painful immune deposition)
- Janeway lesions (non painful)
- Finger clubbing (non specific immune deposition)
How to investigate for infective endocarditis?
Blood cultures: 3 prior to therapy Echocardiography: presence of vegetation and complications CXR ECG Urine microscopy Inflammatory markers FBC, U&Es, LFTs
What is the most common pathogen responsible for bacterial endocarditis infections
Most common are gram positive bacteria in the mouth and on the skin (streptococci, S. aureus)
Less common are gram negative bacteria
Fungal is rare
What is the duke criteria?
Used to make a diagnosis of endocarditis
2 major criteria confirms diagnosis
- Positive blood cultures from at least two separate cultures
- Evidence of vegetation from echocardiography
Minor criteria:
- Predisposition (Heart condition
- Fever
- Microbiological evidence single positive blood culture
- Vascular phenomena (e.g. Janeway lesions)
What is the treatment of endocarditis?
Antibiotics
- tailored to sensitivity of identified pathogen
- bactericidal
- prolonged courses
Which antibiotics are used for the treatment of endocarditis?
In community acquired:
Ampicillin with
flucloxacillin/oxacillin with
gentamicin
In early prosthetic valve surgery:
Vancomycin with
gentamicin with
rifampicin (good at penetrating tissue and eradicating bacteria associated with prosthetic infections)
What is the first two weeks of therapy called?
Critical phase
What is the phase called after 2 weeks of therapy?
Continuation phase
What can occur in the critical phase?
- Complications
- Preferred inpatient treatment
- Consider OPAT (outpatient parenteral antibiotic therapy) if patient stable
