What are the contraindications for pulmonary function tests (PFTs)?

Contraindications for Pulmonary Function Tests

Pulmonary function tests should not be performed in patients with acute cardiovascular conditions, recent surgeries, or other specific medical conditions that increase risk of adverse events or compromise test quality. 1

Absolute Contraindications

• Acute cardiovascular conditions:

  • Recent myocardial infarction (within 3-5 days) 1
  • Unstable angina 1
  • Uncontrolled arrhythmias causing symptoms or hemodynamic compromise 1
  • Active endocarditis 1
  • Acute myocarditis or pericarditis 1
  • Symptomatic severe aortic stenosis 1
  • Uncontrolled heart failure 1

• Acute pulmonary conditions:

  • Acute pulmonary embolus or pulmonary infarction 1
  • Significant pulmonary hypertension 1

• Vascular conditions:

  • Thrombosis of lower extremities 1
  • Suspected dissecting aneurysm 1

• Other:

  • Syncope 1
  • Recent thoracic, abdominal, or head surgery 2

Relative Contraindications

• Cardiovascular conditions:

  • Left main coronary stenosis or equivalent 1
  • Moderate stenotic valvular heart disease 1
  • Severe untreated arterial hypertension (>200 mmHg systolic, >120 mmHg diastolic) 1
  • Tachyarrhythmias or bradyarrhythmias 1
  • High-degree atrioventricular block 1
  • Hypertrophic cardiomyopathy 1

• Pulmonary conditions:

  • Uncontrolled asthma 1
  • Pulmonary edema 1
  • Respiratory failure 1
  • Room air desaturation at rest ≤85% 1
  • Moderate to severe pulmonary disease (FEV1 or FVC <70% of predicted or FEV1:FVC ratio <65%) 1
  • Low baseline lung function (FEV1 <1.5 L or <60-70% predicted in adults) 3

• Other medical conditions:

  • Mental impairment leading to inability to cooperate 1
  • Orthopedic impairment that compromises test performance 1
  • Advanced or complicated pregnancy 1
  • Electrolyte abnormalities 1
  • Acute noncardiopulmonary disorder that may be aggravated by testing 1

Infection Control Considerations

• Patients with active infections may pose transmission risks, particularly those with tuberculosis 3
• There is evidence that contaminated lung function equipment may contribute to infections, with one reported case of TB skin-test conversion following exposure to a spirometer previously used by a patient with TB 3
• Immunocompromised patients may be at higher theoretical risk, though direct evidence of increased infection risk during PFT is lacking 3
• In-line filters are commonly used to reduce infection transmission risk 3

Risk Reduction Strategies

• Ensure proper monitoring during and after the procedure 1
• Have resuscitation equipment immediately available 1
• Place a chair behind standing patients to prevent falls from syncope 1
• Consider supplemental oxygen for patients with resting desaturation 1
• For patients with poor finger perfusion, use ear or forehead oxygen saturation monitors 1
• For patients with decreased oral aperture, consider using a pediatric mouthpiece 1

Timing Considerations After Medical Events

• Traditional recommendations suggested waiting 6 weeks after surgical procedures, but modern less invasive surgical techniques may allow testing after <3 weeks in many cases 2
• For myocardial infarction, waiting at least 3-5 days is recommended 1

Common Pitfalls

• Failing to identify contraindications during pre-test screening 3
• Difficulty interpreting results in patients with baseline airway obstruction 3
• Not recognizing when a test should be postponed for patient safety 1
• Inadequate infection control measures, particularly for immunocompromised patients 3

Understanding these contraindications is essential for ensuring patient safety and obtaining reliable test results. While PFTs are generally safe procedures with minimal risk when properly performed, identifying patients with these contraindications can prevent adverse events and ensure appropriate test interpretation 2, 4.