Viva - Infective Endocarditis Flashcards

1
Q

Define Infective Endocarditis

A

Microbial infection of a native or prosthetic heart valve
OR the mural endocardium

This leads to formation of vegetations and tissue destruction

Has a propensity for haematogenous spread, therefore is a multi system disorder

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2
Q

How can IE be divided

A

Acute - fulminant course over days to weeks, due to S.aureus and results in spread

Subacute - slowly over weeks to months and less likely to cause metastatic infection

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3
Q

Risk factors for IE

A
Prosthetic valves
IVDU
Congenital heart disease
Hx of endocarditis
Damaged valves e.g  rheumatic fever
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4
Q

Describe the clinical manifestation of IE

A

Non specific - weight loss, anorexia, neight sweats, malaise, nausea, vomiting.

Valvular involvement - murmur, failure due to valvular incompetencce

Bacteraemia - fever, CRP

Septic emboli - spleen, kidney, heart, brain

Immune complex formation

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5
Q

How do the septic emboli present

A

Splenic - LUQ pain, left side pleural effusion, rub

Renal - infarction, hametauria, flank pain

Coronary - MI / arrythmias

Cerebral - focal neurology, stroke

Pulmonary - breathlessness, RH involvements

Janeways lesions (macular plaques on palms

Splinter haemorrhages

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6
Q

How does immune complex formation present

A

Interstitial nephritis or glomerularnephritis due to deposition in the kidney

Immune mediated synovitis, MSK

Immune mediated myocarditis - palpitation

Oslers nodes - deposition in hands and feets

Roth spots - retinal haemorrahge

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7
Q

Causative organisms in native valves

A

Gram Pos bacterai - S.Aureas

Native valve;
Streptococci
Staph aureaus - MSSA in community IE
MRSA - nosocomial infection, wound infection, lines

Enterococci

HACEK

Haemophillus,
Actinobaccilus
Cardiobacterium hominis
Kingella

Rare
Q fever - rickettsia
Mycoplasma
Legionella

Fungal and pseudomonas in IVDU

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8
Q

causitive organisms in prosthetic valves

A

Early or late

Early - S.aureus
Enterococci
Fungi, candida, aspergillus
Coag neg staph

Late - s. aureus
Coag neg staph

Streptococci
Enterococci

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9
Q

How are is diagnosed

A

Modified duke criteria which are baed on micro/clinical or echo findings

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10
Q

Dukes clinical criteria

A

2 major
1 major 3 minor
5 minor

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11
Q

Dukes clinical criteria, Major

A

Blood culture positive for IE with 2 seperate blood cultures or a single positive culture for Coxiella burnetii or antiphase I IgG antibody titre > 1:800

Endocardial involvement:
Abscess, new partial dehiscience of a prosthetic valves
New valve regurgitation
Echo positive : oscilating intracardiac mass or valves

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12
Q

Dukes clinical criteria, minor

A

1) Predisposition or predisposing heart condition or IVDU
2) Fever, temp>38

3) Valve phenominae - Major arterial emboli
Septic pulmonary infarcts
Mycotic aneurysm
Intracranial haemorrhages

4) immune pnenomena
Oslers, Roth, Positive Rh Factor

5) Microbiology - blood culture not meeting major criteria

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13
Q

Dukes patholigcal criteria

A

Micro-organism - culture or histology in a vegetation or vegetation that embolised or intra-cardiac absess

Pathologic lesion - confirmed by histology

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14
Q

How to treat

A

Resus and supporitve care

Ix - TTE, TOE better image quality
ECG, 
Bloods including inflam markers and renal
Urinalysis
CXR

3 Aggressive Abx AFTER blood cultures
3 sets of bloods of cultures from different sites

Micro advice

Empirical - fluclox and gent, adjust to sensitivity

Prolonged tx

Cardiac surgery

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15
Q

When to do heart surgery

A
Aortic stenosis or regurg leading to failure
Valve dehiscience
Myocardial abscess or fistula
Fungal
High risk of emboli (vegetation > 10mm)
Persistant cultures despite tx
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16
Q

Issues with IVDU

A

Classically IE with IVDU affect the Right heart

Frequently present with pneumonia and empyema

Predominance of tricuspid valve issues

therefore septic PE is a real risk

Organisms - pseudomonas aeruginose and aureus.

Greater risk of fungal - negative cultures plus vegetations

17
Q

What about prophylaxis

A

NICE 2008: weak evidence, not recommended

BUT

In case of infection at the operative site - give Abx in high risk patients with

Valvular heart disease
Previous valve replacement
Structural congential heart disease (exc. ASD, VSD, PDA that have been repaired)