Chest xray in community acquired pneumonia (CAP)

When should a chest radiograph be performed in the community?

• not necessary to perform a chest radiograph in patients with suspected community acquired pneumonia (CAP) unless (1,2):
  • the diagnosis is in doubt and a chest radiograph will help in a differential diagnosis and management of the acute illness
  • progress following treatment for suspected CAP is not satisfactory at review
  • the patient is considered at risk of underlying lung pathology such as lung cancer
    
    
• when should the chest radiograph, if previously undertaken, be repeated during recovery?
  • the chest radiograph need not be repeated prior to hospital discharge in those who have made a satisfactory clinical recovery from CAP
  • guidance suggests that a chest radiograph should be arranged after about 6 weeks for all those patients who have persistence of symptoms or physical signs or who are at higher risk of underlying malignancy (especially smokers and those aged >50 years) whether or not they have been admitted to hospital (1,2)
    • note though that some expert opinion suggests (3):
      • in some series up to 10% of pneumonia has an underlying lung cancer
        • therefore all consolidation on CXR should be followed to resolution
        • it takes 6 weeks for radiological clearance of pneumonia on CXR (longer with COPD)
        • If not cleared at 6 weeks then refer as two week wait (TWW) with persistent consolidation
  • further investigations which may include bronchoscopy should be considered in patients with persisting signs, symptoms and radiological abnormalities at around 6 weeks after completing treatment (1,2)
  • it is the responsibility of the hospital team to arrange the follow-up plan with the patient and the general practitioner for those patients admitted to hospital (1,2)

Reference:

1, 2. British Thoracic Society. 2015 - Annotated BTS guideline for the management of CAP in adults (2009) summary of recommendations. Jan 2015

3. Dr Judith Drought Respiratory Consultant, University Hospital Coventry & Warwickshire, Walsgrave, Coventry Clifford Bridge Rd, Coventry CV2 2DX (May 10th 2018)