Lung Function Testing

What is Lung Function Testing?

Lung function testing, or spirometry, is used in the practice to assess the functioning of the lungs and the respiratory system. This test provides valuable information about how well a person's lungs are working, and how effectively oxygen is being delivered to the bloodstream, and carbon dioxide is being removed, from the body. Lung function testing is often used to diagnose and monitor various respiratory conditions, such as asthma, chronic obstructive pulmonary disease (COPD), and interstitial lung diseases.

Who might have Lung Function Testing?

Lung Function Testing is advisable for individuals who exhibit symptoms or risk factors for respiratory diseases, including:

• Shortness of breath
• Chronic cough
• Wheezing
• Chest tightness
• Smokers or former smokers
• Those with a family history of lung diseases
• Individuals with exposure to environmental pollutants or occupational hazards
• Those with known respiratory conditions, such as asthma or COPD, who need monitoring and assessment of their disease progression and treatment effectiveness.

Your doctor will recommend this test if it is considered useful.

Benefits of Lung Function Testing

• Diagnosis: Lung Function Testing helps diagnose various respiratory conditions such as asthma, chronic obstructive pulmonary disease (COPD), interstitial lung diseases, and more. Accurate diagnosis allows for appropriate treatment planning.
• Disease Monitoring: Lung Function Testing is essential for monitoring the progression of respiratory diseases. It helps healthcare professionals assess the effectiveness of treatments and make necessary adjustments.
• Early Detection: Early detection of lung problems can lead to timely intervention and improved outcomes. Lung Function Testing can detect issues before noticeable symptoms appear.
• Assessment of Disease Severity: Lung Function Testing provides quantitative data that helps healthcare providers determine the severity of respiratory conditions. This information guides treatment decisions.
• Treatment Planning: Lung Function Testing results assist healthcare professionals in tailoring treatment plans to individual patients. This may include medication adjustments, lifestyle modifications, or pulmonary rehabilitation programs.
• Surgical Risk Assessment: For individuals considering surgery, lung function tests can help assess whether their lungs can withstand the stress of anaesthesia and surgery. This is particularly important for individuals with lung diseases.
• Fitness to Perform Activities: Some occupations or activities require good lung function. Testing can determine if individuals are fit to perform certain tasks, especially in jobs that involve exposure to dust, chemicals, or physical exertion.
• Research and Clinical Trials: Lung Function Testing data is valuable in research studies and clinical trials to understand lung diseases and develop new treatments.

Types of Lung Function Testing

• Spirometry: Measures the volume and flow rate of air inhaled and exhaled. It's commonly used to diagnose and monitor conditions like asthma and COPD.
• Peak Expiratory Flow (PEF) Measurement: Measures the maximum flow of air that can be forcefully exhaled. It's commonly used to monitor asthma and assess its severity.

These tests can be performed in the practice.  If necessary, your doctor will refer you to a hospital laboratory for further tests such as:

• Lung Volume Measurement: Determines various lung capacities and volumes, aiding in diagnosing restrictive lung diseases.
• Diffusion Capacity Test: Assesses how well the lungs transfer oxygen from inhaled air into the bloodstream and remove carbon dioxide.
• Body Plethysmography: Measures lung volumes and capacities by having the individual breathe in a sealed chamber.
• Bronchial Provocation Tests: Measures how the airways respond to specific irritants or allergens, aiding in diagnosing conditions like asthma.
• Exercise Testing: Assesses lung function during physical activity, which helps understand exercise-induced breathing difficulties.
• Arterial Blood Gas (ABG) Analysis: Measures oxygen and carbon dioxide levels in arterial blood, providing insight into gas exchange efficiency.
• Fractional Exhaled Nitric Oxide (FeNO) Test: Measures the nitric oxide level in exhaled breath, aiding asthma diagnosis and management.
• Methacholine Challenge Test: Evaluates airway hyperresponsiveness by assessing how the airways react to methacholine, a bronchoconstricting substance.
• Six-Minute Walk Test: Measures the distance an individual can walk in six minutes, providing insight into exercise tolerance and lung function.

What to do Before a Lung Function Testing? 

• Follow Instructions: Your doctor will provide specific instructions on how to prepare for the tests. Follow them carefully to ensure accurate results.
• Medications: Inform your doctor about any medications you're taking, especially inhalers and respiratory medications. They might recommend adjusting or temporarily discontinuing certain medications before the test.
• Avoid Certain Substances: Avoid smoking, caffeine, and heavy meals before the test, as they can affect lung function.
• Clothing: Wear comfortable clothing that doesn't restrict your breathing.
• Health History: Be prepared to provide information about your medical history, including any previous lung conditions, surgeries, or allergies.

Lung Function Testing Procedure

• Spirometry: You will be asked to take a deep breath and exhale forcefully into a spirometer. The technician will guide you on how to perform the test properly.
• Peak Expiratory Flow (PEF) Measurement: You'll be asked to take a deep breath and exhale forcefully into a handheld peak flow metre device.

What to Expect After a Lung Function Testing?

• Normal Activities: In most cases, you can resume your normal activities immediately after the tests.
• Discuss Results: Your doctor will discuss the results with you. They will interpret the data and explain what it means for your lung health.
• Treatment Adjustments: If you have a known respiratory condition, the test results might lead to adjustments in your treatment plan, medications, or other interventions.
• Follow-up: Depending on the results, you might need further tests, treatments, or follow-up appointments.
• Potential Discomfort: Some tests might cause minor discomfort or fatigue due to the effort required. You might experience temporary shortness of breath or dizziness, but these usually subside quickly.
• Next Steps: If the results are abnormal, your doctor will work with you to develop a plan for managing your condition and improving your lung health.

Lung Function Testing Risks

Lung function testing is generally considered safe and non-invasive. However, there can be minimal risks associated with certain tests:

• Discomfort: Some tests, such as spirometry and lung volume measurement, might cause mild discomfort due to the effort required during breathing manoeuvres.
• Dizziness or Shortness of Breath: Exertion during testing could lead to temporary dizziness or shortness of breath, but these symptoms typically subside quickly.
• Bronchospasm: In individuals with pre-existing respiratory conditions like asthma, some tests that involve deep breathing or exposure to irritants could trigger bronchospasm (narrowing of the airways).
• Infection Risk: If the equipment used for testing is not properly sterilised or cleaned, there could be a risk of infection. However, healthcare providers follow strict hygiene protocols to prevent this.
• Rare Complications: In extremely rare cases, certain individuals might experience more serious complications, such as pneumothorax (collapsed lung), but these are exceptionally uncommon.

Delayed Lung Function Testing

While timely lung function testing is preferred for accurate diagnosis and treatment planning, a slight delay in testing is unlikely to impact the overall prognosis significantly. However, for individuals with symptoms or risk factors for lung diseases, delaying testing for an extended period could result in:

• Progression of Disease: Delaying testing might allow a respiratory condition to worsen without appropriate intervention, leading to decreased lung function and potentially irreversible damage.
• Misdiagnosis: Some lung conditions share similar symptoms, and delayed testing could lead to a misdiagnosis or incorrect treatment.
• Missed Opportunities: Early detection and management of lung conditions can lead to better outcomes. Delayed testing might miss opportunities for implementing effective treatments.
• Quality of Life: Respiratory symptoms can significantly affect an individual's quality of life. Timely testing and appropriate treatment can help improve symptoms and overall well-being.

It's important to balance the need for timely testing with practical considerations and individual circumstances. If there's a concern about delaying lung function testing, it's advisable to consult with a doctor to determine the best course of action based on the specific situation.