Is difficulty breathing and oxygen support a contraindication for pulmonary function tests (PFTs)?

Difficulty Breathing and Oxygen Support in Pulmonary Function Testing

Difficulty breathing is not a contraindication for pulmonary function tests (PFTs), but supplemental oxygen should be temporarily discontinued during the actual testing procedure to ensure accurate results, while being available for immediate use before and after testing for patients who require it. 1

Assessment Before PFTs

• Evaluate baseline respiratory status, including oxygen saturation via pulse oximetry before testing 1
• Document any existing oxygen requirements and current respiratory symptoms 2
• For patients with known COPD who use supplemental oxygen, note their baseline oxygen saturation targets (typically 88-92%) 1, 2
• Assess for signs of severe respiratory distress that might warrant postponing the test, such as:
  • Respiratory rate >30 breaths/min 2
  • Severe hypoxemia despite oxygen therapy 1
  • Signs of right heart failure or pulmonary hypertension 1

Management During Testing

• Supplemental oxygen should be temporarily discontinued during the actual measurement phase of pulmonary function testing to avoid interference with test results 1
• Patients with pulmonary vascular diseases require special consideration as exercise testing may not be indicated or should be approached very cautiously in those with:
  • Recent history of syncope 1
  • Arrhythmias 1
  • Signs of right heart failure 1

Oxygen Management Protocol

• For patients who normally use oxygen:
  • Remove supplemental oxygen only for the brief duration of the actual test maneuvers 1
  • Have oxygen immediately available for use between testing efforts 2
  • Monitor oxygen saturation continuously during the testing process 2
  • Resume oxygen therapy immediately after completion of each test component 1, 2

Special Considerations

• For patients with interstitial lung disease (ILD):

  • Most patients with moderate to severe pulmonary fibrosis show arterial desaturation during exertion 1
  • Supplemental oxygen should be readily available as these patients may desaturate rapidly 3
  • Careful monitoring is required as oxygen desaturation may be difficult to correct 1

• For patients with COPD:

  • Target oxygen saturation of 88-92% to reduce mortality risk 1, 2
  • Avoid high-flow oxygen (>28%) before blood gas results are available, as this can worsen hypercapnic respiratory failure 2
  • Use compressed air rather than oxygen to drive nebulizers in patients with elevated PaCO₂ 2

Post-Testing Management

• Resume oxygen therapy immediately after testing is complete 2
• Titrate to maintain target oxygen saturation (88-92% for COPD patients) 1, 2
• Monitor for signs of respiratory distress for at least 10 minutes after testing 1
• Document any changes in oxygen requirements or respiratory status compared to baseline 2

Contraindications to Consider

While difficulty breathing itself is not a contraindication, PFTs may be contraindicated in patients with:

• Severe pulmonary hypertension with recent syncope or arrhythmias 1
• Unstable cardiovascular status 1
• Acute respiratory failure requiring high levels of supplemental oxygen that cannot be briefly discontinued 1
• Recent pneumothorax or hemoptysis 1

Remember that while difficulty breathing is common in patients requiring PFTs, the test should be conducted with appropriate monitoring and with oxygen support available immediately before and after the actual measurement procedures 1, 2.