Infective endocarditis

Question 1

Definition

Answer 1

Infection of endocardial surface of the heart
Acute= days to weeks
Subacute= weeks to months->vague constitutional

Question 2

Etiology

Answer 2

Viridans group Strep
S. Aureus->catheter, IVDU
Enterococci->previous GU surgery/instrumentation
Coagulase negative Staph->neonates, prosthetic
Fungi
Coxiella burneti
S bovis->elderly, adenoC of bowel
HACEK in culture negative

Question 3

Pathophysiology

Answer 3

Infection on valve which have sustained endothelial injury
Platelets and fibrin adhere to collagen, prothrombotic mileui
Bacteremia leads to colonisation of thrombus, further deposition= mature infected vegetation

Question 4

Presentation in native valve

Answer 4

Non IVDU: viridans, enterococci, staph

IVDU: Staph, strep, gram negative. Associated with right sided

Question 5

Presentation in prosthetic

Answer 5

Early: Staph and coagulase negative
Late: Strep, enterococci, staph

Question 6

High risk population

Answer 6

History of previous
Prosthetic
CHD
Cardiac transplant

Denta
Invasive of respiratory, infected skin, MSK

Question 7

Clinical features

Answer 7

fever/chills (common)
night sweats, malaise, fatigue, anorexia, weight loss, myalgias (common)
weakness (common)
arthralgias (common)
headache (common)
shortness of breath (common)
meningeal signs (uncommon)
cardiac murmur (uncommon)
Janeway lesions (uncommon)
Osler nodes (uncommon)
Roth spots (uncommon)

Question 8

Investigations

Answer 8

FBC->anaemia, leukocytosis
UEC, glucose->N/ +urea
Urinalysis->RBC casts, WBC casts, protein+, pyuria
BC
ECG->prolonged PR, non-specific ST changes
EchoC->mobil, valvular lesions

Question 9

Duke criteria

Answer 9

2 major or 1 major and 3 minor or 5 minor
1. Major:
+BC->typical organism from 2 separate BC, persistently +ve BC
Evidence of endoC involvement->evidence of mass on echo, abscess, new regurgtation murmur

2. Minor:
   Predisposing heart/IVDU
   Fever >38
   Vascular->major arterial emboli, septic pulmonary infarcts, myoctic aneurysm, conjunctival hemorrhage, JWL
   Immunological: GN, Osler nodes, Roth spots, RF
   Microbiological->+ve not meeting major
   Echo->Consistent, not meeting major

Question 10

Management

Answer 10

ABC
Oxygen
2 large IV cannula, catheter if required
Manage decompensated HF if required
BC, FBC, urinalysis, glucose
Call cardiology, ID, surgery
Start antibiotics, fluids
Admit
Arrange Echo
Repeat BC
Regular monitoring
Considerations for surgery

Question 11

Antibiotic regime

Answer 11

Native valve empirical: benpen (Vanc if suspect MRSA) + gentamicin + flucloxacillin

If hypersensitive to penicillin-> gent + vanc + cefazolin

Prosthetic/PaceM: Vanc + fluclox + gent

Question 12

Indications for surgical management

Answer 12

Intractable congestive heart failure caused by valve dysfunction >1 serious systemic
embolic episode, or large (>10 mm) vegetation with high risk for embolism
Uncontrolled infection, eg, positive cultures after 7 d of therapy
No effective antimicrobial therapy (eg, fungal endocarditis)
Most cases of prosthetic valve endocarditis, especially S aureus prosthetic valve infection
Local suppurative complications, eg, myocardial abscess

Question 13

Recommendations for followup

Answer 13

1. Before completing antimicrobial therapy, patients should receive transthoracic echocardiogram (TTE) to establish a new baseline.
2. In addition, it is generally recommended that patients with prosthetic valve endocarditis undergo trans-oesophageal echocardiogram (TOE) at the completion of therapy.
3. All patients should have blood cultures done at 1 and 2 weeks following therapy to ensure they are not persistently bacteraemic.
4. Patients with risk factors such as intravenous drug use should be referred promptly to a cessation programme. I
5. n addition, all patients should be educated regarding the signs and symptoms of IE, as, if there is a recurrence, early treatment may prevent long-term complications.