Infective Endocarditis

Infective endocarditis

- common in pt with abnormal valves : rheumatic fever, valve surgery/replacement/ congenital abnormalities

- common bacteria: staphylococcus aureus, strepto, psudomonas aeruginosa, bartonella

Sample question:

A patient 40 years old male got admitted to the hospital, with fever for 7 days, will chills and rigor

Bp 120/80, pr 100bpm , T 38.5

Patient GCS 11, blur and unable to cooperate properly 

On physical examination with a pansystolic murmur heard on the left sternal border 

Presence of nodules on both arms

What is your diagnosis?

Ddx: Infective endocarditis

Peripheral signs: 

1. Nodes of the hand should prompt for more history: for example any needle injection history or not prior to this or it is just nodules. To differentiate between janeway lesion and osler nodes. 

- If they are IVDU highly suspected IE 

- generalised petechial as well due to bacterial peritonitis

- splinter hemorrhage in proximal nail plate

- osler nodes: cause by the infection in blood stream a type of neutrophilic vasculitis

- janeway lesion: bleeding in skin- staph aureus, microabscess from necrosis and inflammatory infiltrate--> on palms, soles, thenear, hypothenar and plantar surface of toes.

Central signs:

- hematuria: glomerulonephritis

- septic embolisation: lung embolisation

- Roth spots: red spot in the eye

Cardiac symptoms

2. Murmur heard at left sternal border

- tricuspid border is related to the tricuspid regurgitation- common on those heart valves with vegetative growth

- tricuspid valve endocarditis usually in drug abusers. 

    - damage by persistent bombardment of the endothelial surface with particulate matter from injected material 

- TR is accentuated with deep inspiration

- death usually from pulmonary regurgitation and RDS

or

- HF

- bradycardia

3. Fever most likely cause by the infection

Neurological symptoms

4. Drop of GCS 

- delirium - in meningitis/ encephalopathy

- confusion, drowsiness, reduced consciousness, vomiting, seizure - intracranial bleeding

- hemiparesis/aphasia: ischemic stroke

Any criteria to help with diagnosis of IE?

- Definite IE:

pathological criteria: 

• microorganism demonstrated in culture/ histological examination of vegetation
• pathological lesion: confirm by histological examination with active endocarditis

clinical criteria: 2major/1major and 3minor/ 5 minor

- Possible IE: 1 major and 1 minor / 3minor

- Rejected IE: firm alternate diagnosis/ resolution of symptoms <4days antibiotic/ does not meet criteria above

- DUKEs criteria: 

either 1 major 1 minor or 1 major 3 minor or 5 minor

 Major

• Positive blood cultures for IE

Evidence of endocardial involvement 

 Minor

• Predisposition: IVDU

• Fever>38

• Vascular phenomena: janeway lesion

• Immunologic phenomena: glomerulonephritis

• Microbiologic phenomena: positive blood culture that doesnt meet major criteria

Blood Ix to be sent 

- FBC: anemia, platelet count (thrombocytopenia)

- RFT: any acute kidney injury (a complication of IE)

- Electrolytes; to check if there are any depletion that causes the gcs drop

- LFT: any liver disease: hepatits 

- Infective screening

- Urine C+S: any hematuria or UTI

- CRP, ESR: infection

- coag: if pt on anticoagulation

- Blood C+S : 

1. to be taken 3 times from different sites before antibiotics/ treatment

- if remain negative for 5 days: consider negative

2. 3-4 days after commencement of treatment to document the eradication

Echocardiogram:

- irregular echo mass attached to valve

- if its tricuspid will relate to RV dilation, paradoxical septal motion and dilated IVC

ECG: what to look out for?

- Any changes for AV block or conduction abnormalities suggesting intracardiac extension of infection

CXR: Note multiple cavitating lung nodules due to septic pulmonary emboli.

- infiltration, cavitation, pleural effusion and empyema are common in S. aureus infection

Treatment: 

- Medical

- strepto: common among the young with  preexisting heart/ valve disease

- staphylo : common among old with healthcare related IE

while awaiting for investigation

- should give medical therapy first:

1. antibiotics with good coverage of staph aureus, streptococcus and pseudomonas

-6-8 weeks of parental therapy required. 

MONITOR treatment

- vital signs, regular examination

- daily ECG

- repeat echo once complete antibiotic (abx)

- review anticoagulant used

- surgical intervention

indications: 

1. persistent sepsis 

2. congestive heart failure

3. presented with cardiogenic shock

4. vegetation on echo >10mm in diameter

 

types of surgery: valve sparing debridement , valvulectomy with prosthetic replacement

Common complications:

1. Heart Failure: valve dysfx

- Diuretics (e.g. furosemide). 

•  indicated for patients with symptoms of acute pulmonary oedema or fluid overload (raised jugular venous pressure; JVP and ankle oedema). 
• Angiotensin converting enzyme (ACE) inhibitors. 
• Beta-blockers: 
• should also not be used in aortic regurgitation as this will increase diastolic time and regurgitation volume.

2. Persistent infection: causes AV block

3. Systemic embolism: occur in left sided IR within the first 2 weeks of therapy

- common sites are brain and spleen

4. neurological complications:

- early in course of IE (first 2 weeks)

- can be ischemic/hemorrhagic stroke/ aneurysm

    - to w/hold anticoagulation base on severity of complication

Prophylaxis

1. Antimicrobial prophylaxis not encouraged for cardiac patients

2. to consult with dentist prior invasive dental/medical procedure regarding the risk from IE

3. maintain good oral and skin hygiene

Reference:

1. CPG for IE from MOH