Spirometry is a common and essential diagnostic test used to assess how well your lungs work by measuring how much air you inhale, how much you exhale, and how quickly you exhale. It is widely used to diagnose and monitor lung conditions such as asthma, chronic obstructive pulmonary disease (COPD), and other disorders that affect breathing.

How Spirometry Works

Preparation:

  • Patients are typically advised to avoid smoking or heavy meals before the test.
  • Certain medications may need to be withheld as directed by the healthcare provider.

Procedure:

  1. Positioning: The patient is seated and a nose clip may be applied to ensure all air is expelled through the mouth.
  2. Mouthpiece: The patient places a sterile mouthpiece attached to the spirometer into their mouth.
  3. Breathing Instructions: The patient will be instructed to take a deep breath in and then exhale forcefully and completely into the mouthpiece.
  4. Repeated Efforts: The test is usually repeated at least three times to ensure consistency and reliability of the results.

Key Measurements

  1. Forced Vital Capacity (FVC):
    • The total amount of air exhaled during the spirometry test after taking the deepest breath possible.
  2. Forced Expiratory Volume in 1 Second (FEV1):
    • The amount of air exhaled in the first second of a forced breath.
  3. FEV1/FVC Ratio:
    • The ratio of FEV1 to FVC, used to differentiate between obstructive and restrictive lung diseases.

Interpretation of Results

  • Normal: An FEV1/FVC ratio of 70% to 80% is generally considered normal, depending on age, sex, height, and ethnicity.
  • Obstructive Lung Disease: A reduced FEV1/FVC ratio indicates obstructive lung diseases such as asthma or COPD, where the airways are narrowed.
  • Restrictive Lung Disease: A normal or high FEV1/FVC ratio with a reduced FVC suggests restrictive lung diseases, where the lung volume is reduced but the airways are not narrowed.

Clinical Uses

  1. Diagnosis:
    • Asthma: Spirometry can help diagnose asthma by identifying reversible airway obstruction.
    • COPD: Used to diagnose and stage COPD, determining the severity and monitoring progression.
    • Other Conditions: Helps in diagnosing conditions like cystic fibrosis, pulmonary fibrosis, and bronchiectasis.
  2. Monitoring:
    • Disease Progression: Regular spirometry tests can monitor the progression of lung diseases.
    • Treatment Efficacy: Assessing the effectiveness of medications like bronchodilators and steroids in managing asthma or COPD.
  3. Pre-Surgical Assessment:
    • Evaluates lung function before major surgeries, particularly in patients with known respiratory issues.
  4. Occupational Health:
    • Used in occupational health to monitor workers exposed to respiratory hazards.

Benefits

  • Non-Invasive: The test is simple, painless, and non-invasive.
  • Quick and Convenient: Can be completed in a few minutes in a clinical setting.
  • Informative: Provides valuable information about lung function and helps guide treatment decisions.

Risks and Limitations

  • Effort-Dependent: The accuracy of the test depends on the patient’s effort and ability to follow instructions.
  • Transient Side Effects: Some patients may feel lightheaded or short of breath briefly after the test.
  • Contraindications: Not suitable for patients with recent heart attack, eye surgery, or those with severe respiratory distress.

Spirometry is a crucial tool in the diagnosis and management of respiratory conditions, providing critical insights into lung function and aiding in effective treatment planning.

At ARC Medicals we do not diagnose but our tests and results can be used to help inform a GP or for your benefit in monitoring your condition.

For more information or to book your Spirometry test please call our friendly team on 01443 303003 or complete the form below and someone will contact you shortly.