Paediatrics: Infection: infective bacterial endocarditis

Infection: infective bacterial endocarditis

There are both acute and subacute forms of infection of the endocardium. Children at risk are those with turbulent blood flow through the heart or where prosthetic material has been inserted following surgery: e.g.

·  PDA or VSD;

·  coarctation of aorta;

·  previous rheumatic fever.

The most common pathogens associated with infective bacterial endo-carditis are:

·  Streptococcus viridans (50% cases): often after dental procedures.

·  Staphylococcus aureus: often related to central venous catheters.

·  Group D streptococcus (enterococcus): often after lower GI surgery.

An organism is not found in up to 10% of cases.

Clinical features

·  In the early stage symptoms are mild.

·  Prolonged fever persisting over several months may be the only feature.

·  Alternatively, rapid onset of high intermittent fever can occur.

·  Non-specific symptoms include:

·  myalgia and arthalgia;

·  headache, weight loss, night sweats.

Examination

This may be variable, but classic signs include:

·  pallor/anaemia;

·  nail bed—splinter haemorrhages;

·  tender nodules—fingers/toes (Osler’s nodes);

·  erythematous palms/soles of feet (Janeway lesions);

·  finger clubbing (late);

·  necrotic skin lesions;

·  splenomegaly;

·  haematuria (microscopic)

·  retinal infarcts (Roth’s spots);

·  heart murmurs (change in character with time).

Diagnosis

A high index of suspicion is required. Blood tests include FBC (raised

WCC),  ESR      (raised), CRP      (raised)   and    repeated      blood cultures.

Echocardiography is needed to look for valve ‘vegetations’.

Prophylaxis 

This is no longer routinely advised.

Treatment

·Antibiotic therapy: should be started as soon as possible. Delays may result in progressive endocardial damage and deterioration in cardiac function. High dose IV antibiotics (e.g. penicillin/vancomycin) are required for a minimum of 6wks.

·Bed rest is recommended and heart failure should be treated.

·Surgery will be necessary for removal of infected prosthetic material.

Prognosis

Even with antibiotic treatment mortality may be as high as 20% and com-plications (50–60%) include heart failure. Systemic emboli from left-sided vegetations may result in brain abscess and stroke.