Investigations

In patients with acute dyspnoea the following investigations can be done (1):

• 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 dyspnoea 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: (2)
  • echocardiography - to diagnose cardiac causes of chronic dyspnoea (especially in patients with suspected heart failure)
  • brain natriuretic peptide (BNP) - to diagnose heart failure (3)
  • lung function tests - to identify restrictive lung and obstructive lung disorders (4)
  • D-dimer testing is particularly useful in patients with a low clinical probability assessment for PE (5)

References:

1. Zoorob RJ, Campbell JS. Acute dyspnea in the office. Am Fam Physician. 2003 Nov 1;68(9):1803-10.
2. Karnani NG, Reisfield GM, Wilson GR. Evaluation of chronic dyspnea. Am Fam Physician. 2005 Apr 15;71(8):1529-37.
3. Trinquart L, Ray P, Riou B, et al. Natriuretic peptide testing in EDs for managing acute dyspnea: a meta-analysis. Am J Emerg Med. 2011 Sep;29(7):757-67.
4. Dempsey TM, Scanlon PD. Pulmonary Function Tests for the Generalist: A Brief Review. Mayo Clin Proc. 2018 Jun;93(6):763-71.
5. Konstantinides SV, Meyer G, Becattini C, et al. 2019 ESC guidelines for the diagnosis and management of acute pulmonary embolism developed in collaboration with the European Respiratory Society (ERS): the Task Force for the diagnosis and management of acute pulmonary embolism of the European Society of Cardiology (ESC). Eur Respir J. 2019 Sep;543-603.