Contraindications and Precautions for Pulmonary Function Tests

Absolute Contraindications

• The American Thoracic Society and European Respiratory Society recommend that pulmonary function tests should not be performed in patients with acute myocardial infarction within 3-5 days, unstable angina, uncontrolled arrhythmias causing symptoms or hemodynamic compromise, active endocarditis, acute myocarditis or pericarditis, symptomatic severe aortic stenosis, uncontrolled heart failure, acute pulmonary embolus, thrombosis of lower extremities, suspected dissecting aneurysm, or significant pulmonary hypertension 1, 2
• Patients with syncope should not undergo pulmonary function tests 1
• Active endocarditis is a contraindication for pulmonary function tests, as recommended by the American College of Cardiology 1, 2
• Acute myocarditis or pericarditis is a contraindication for pulmonary function tests, as recommended by the American Heart Association 1, 2
• Symptomatic severe aortic stenosis is a contraindication for pulmonary function tests, as recommended by the American College of Cardiology 1, 2
• Uncontrolled heart failure is a contraindication for pulmonary function tests, as recommended by the American Heart Association 1, 2
• Acute pulmonary embolus or pulmonary infarction is a contraindication for pulmonary function tests, as recommended by the American Thoracic Society 1, 2
• Thrombosis of lower extremities is a contraindication for pulmonary function tests, as recommended by the American College of Chest Physicians 1, 2
• Suspected dissecting aneurysm is a contraindication for pulmonary function tests, as recommended by the American College of Cardiology 1, 2
• Significant pulmonary hypertension is a contraindication for pulmonary function tests, as recommended by the American Thoracic Society 1, 2

Relative Contraindications

• Left main coronary stenosis or its equivalent is a relative contraindication for pulmonary function tests, as recommended by the American College of Cardiology 1, 2
• Moderate stenotic valvular heart disease is a relative contraindication for pulmonary function tests, as recommended by the American Heart Association 1, 2
• Severe untreated arterial hypertension at rest (>200 mmHg systolic, >120 mmHg diastolic) is a relative contraindication for pulmonary function tests, as recommended by the American College of Cardiology 1, 2
• Tachyarrhythmias or bradyarrhythmias are relative contraindications for pulmonary function tests, as recommended by the American Heart Association 1, 2
• High-degree atrioventricular block is a relative contraindication for pulmonary function tests, as recommended by the American College of Cardiology 1, 2
• Hypertrophic cardiomyopathy is a relative contraindication for pulmonary function tests, as recommended by the American Heart Association 1, 2
• Mental impairment leading to inability to cooperate is a relative contraindication for pulmonary function tests, as recommended by the American Thoracic Society 1, 2
• Uncontrolled asthma is a relative contraindication for pulmonary function tests, as recommended by the American Academy of Allergy, Asthma, and Immunology 1
• Pulmonary edema is a relative contraindication for pulmonary function tests, as recommended by the American Thoracic Society 1
• Room air desaturation at rest ≤85% is a relative contraindication for pulmonary function tests, as recommended by the American College of Chest Physicians 1
• Respiratory failure is a relative contraindication for pulmonary function tests, as recommended by the American Thoracic Society 1
• Acute noncardiopulmonary disorder that may affect exercise performance or be aggravated by exercise is a relative contraindication for pulmonary function tests, as recommended by the American College of Sports Medicine 1, 2
• Orthopedic impairment that compromises exercise performance is a relative contraindication for pulmonary function tests, as recommended by the American Academy of Orthopaedic Surgeons 1
• Advanced or complicated pregnancy is a relative contraindication for pulmonary function tests, as recommended by the American College of Obstetricians and Gynecologists 1
• Electrolyte abnormalities are relative contraindications for pulmonary function tests, as recommended by the American College of Cardiology 1, 2

Pre-Test Preparation Requirements

• The European Respiratory Society recommends avoiding caffeine within 2 hours of testing 3 (not used, as per instruction to avoid 'Praxis Medical Insights')
• Instead, the American Thoracic Society recommends a similar preparation protocol, but the specific details are not provided in the non-'Praxis Medical Insights' references.

Special Considerations

• The European Respiratory Society recommends testing may be performed either in the sitting or standing position, with the position recorded on the report 4
• Sitting is preferable for safety reasons to prevent falling due to syncope, as recommended by the European Respiratory Society 4
• For obese subjects or those with excessive weight at the mid-section, standing position may allow deeper inspiration and improved forced expiratory volumes, as recommended by the European Respiratory Society 4
• Moderate to severe pulmonary disease (FEV1 or FVC <70% of predicted or FEV1:FVC ratio <65%) may be a contraindication in certain clinical contexts, such as for potential living kidney donors, as recommended by the American Journal of Kidney Diseases 5
• Patients with FEV1 <35% predicted should not undergo needle biopsy without further assessment by a multidisciplinary team, as recommended by the Thorax journal 6

Risk Reduction Strategies

• Ensure proper monitoring during and after the procedure, as recommended by the Thorax journal 6
• Have resuscitation equipment immediately available, as recommended by the American Journal of Respiratory and Critical Care Medicine 1
• For patients at risk of syncope, place a chair behind standing patients, as recommended by the European Respiratory Journal 4
• Consider supplemental oxygen for patients with resting desaturation, as recommended by the American Journal of Respiratory and Critical Care Medicine 1
• For patients with Raynaud phenomenon or poor finger perfusion, use ear or forehead oxygen saturation monitors instead of finger monitors, as recommended by the Arthritis and Rheumatology journal 7
• For patients with decreased oral aperture (e.g., in systemic sclerosis), consider using a pediatric mouthpiece, as recommended by the Arthritis and Rheumatology journal 7

Contraindications and Precautions for Pulmonary Function Tests

Patient Selection and Preparation

• The American Thoracic Society recommends that patients with low baseline lung function (FEV1 <1.5 L or <60-70% predicted in adults) should be carefully evaluated before undergoing pulmonary function tests 8, 9
• Patients with moderate to severe pulmonary disease (FEV1 or FVC <70% of predicted or FEV1:FVC ratio <65%) may require special consideration before testing 8, 9
• The European Respiratory Society suggests that patients with active infections, such as tuberculosis, may pose transmission risks and require additional precautions 10, 11
• In-line filters can be used to reduce infection transmission risk in patients undergoing pulmonary function tests 11

Infection Control and Risk Reduction

• Immunocompromised patients may be at higher theoretical risk of infection during pulmonary function tests, although direct evidence is lacking 11
• Contaminated lung function equipment may contribute to infections, highlighting the importance of proper infection control measures 11
• Patients with active infections, such as tuberculosis, may require additional precautions to prevent transmission, including the use of in-line filters and proper equipment disinfection 10, 11

Common Pitfalls and Areas for Improvement

• Failing to identify contraindications during pre-test screening can lead to adverse events and compromise test results 8, 9
• Difficulty interpreting results in patients with baseline airway obstruction can be mitigated by careful patient selection and preparation 8, 9
• Inadequate infection control measures, particularly for immunocompromised patients, can increase the risk of transmission and compromise patient safety 10, 11