Paediatrics: Pneumonia

Pneumonia

Pneumonia is an infection of the lower respiratory tract and lung paren-chyma that leads to consolidation. Viruses alone account for 14–35% of all community acquired pneumonia in childhood. In 20–60% of children a pathogen is not found. Common infecting bacterial agents by age are:

·  Neonates: group B streptococcus, Escherichia coli, Klebsiella, Staphylococcus aureus.

·  Infants: Streptoccus pneumoniae, Chlamydia.

·  School age: Streptococcus pneumoniae, Staphylococcus aureus, group A streptococcus, Bordetella pertussis, Mycoplasma pneumoniae.

Certain groups of children are at risk of pneumonia, e.g. those with:

·  congenital lung cysts;

·  chronic lung disease;

·  immunodeficiency;

·  cystic fibrosis;

·  sickle cell disease;

·  tracheostomy in situ.

Diagnosis

History

The patient may have had a recent URTI and may also be complaining of pleuritic chest pain or abdominal pain. The typical history will have:

·  temperature  38.5*C;

·  shortness of breath;

·  cough; with sputum production in older children (>7yrs).

Examination

Check for the following:

·  Signs of respiratory distress: tachypnoea; grunting; intercostal recession; use of accessory muscles for breathing. A resting respiratory rate of 70breaths/min in infants or >50breaths/min in children indicates severe illness.

·  Desaturation and cyanosis: pulse oximetry should be performed in every child admitted to hospital with pneumonia. SpO₂ ≤92% in room air indicates severe illness.

·  General health and lethargy.

·  Auscultation signs of lobar pneumonia: dullness to percussion; crackles; decreased breath sounds; tactile vocal fremitus; bronchial breathing.

Investigations

The investigations that help in diagnosis include:

·  Sputum: culture may be of limited value.

·  Nasopharyngeal aspirate: viral immunofluorescence in infants.

·  Blood: culture should be done in all children with severe bacterial pneumonia (not necessary in community-acquired pneumonia).

·  CXR: not as routine.

·  Pleural fluid: when there is a significant pleural effusion, an aspirated sample should be sent for culture and antigen testing once a drain is inserted.

·Viral titres: save a sample of blood for acute titre testing, which can be assayed the same time as the convalescent sample if a microbiological diagnosis is not made.

Chest X-ray

There are a variety of changes ranging from lobar consolidation to the mere presence of patchy bilateral infiltrates. In general, routine CXR is not needed in children with mild uncomplicated LRTI. In other cases, look for pleural effusions, fluid levels, apparent round pneumonia, cavitation, hilar adenopathy, and any calcification. At follow-up, patients with history of significant acute X-ray change (e.g. lobar collapse, apparent round pneu-monia, empyema) or continuing symptoms will require repeat X-ray.