Investigations

In patients with acute dyspnoea the following investigations can be done:

• pulse oximetry - to determine the level of oxygenation
• chest radiographs - to rule out pneumothorax, pneumonia, COPD, pulmonary oedema, or congestive heart failure
• electrocardiography - to identify ischemia, left ventricular hypertrophy and arrhythmia
• bedside spirometry (to obtain a PEFR) - for exacerbation of asthma or COPD (1)

work-up for patients with chronic dyspnoe include

• initial diagnostic
  • chest radiography - to identify congestive heart failure, pleural disease, chest wall abnormalities
  • electrocardiography - to look for evidence of arrhythmia, cardiac ischemia, ventricular hypertrophy or pericardial disease
  • full blood count - to check for anaemia
  • spirometry - to identify obstructive lung disorders from restrictive lung disorders
• if diagnosis is still not evident further investigations can be carried out:
  • echocardiography - to diagnose cardiac causes of chronic dyspnoea (especially in patients with suspected heart failure)
  • brain natriuretic peptide (BNP) - to diagnose heart failure
  • lung function tests - to identify restrictive lung and obstructive lung disorders (2)

Reference:

• 1. Zoorob RJ, Campbell JS. Acute dyspnea in the office. Am Fam Physician. 2003;68(9):1803-10
• 2. Karnani NG, Reisfield GM, Wilson GR. Evaluation of chronic dyspnea. Am Fam Physician. 2005;71(8):1529-37