Lung Function Laboratory

Clinical service overview

There are a number of different lung function tests that measure different aspects of lung function. Depending on the reason for referral and symptoms, more than one test may be undertaken.

Tests available include:

• Spirometry – A measure of air movement in and out of the lungs. Spirometry assists with identifying ventilatory defects and can be performed before and/or after bronchodilator for assessment of reversibility of airflow obstruction
• TLCO – Transfer across the lung of carbon monoxide. This test is an assessment of gas exchange/alveolar membrane integrity
• Lung Volumes (body plethysmography) – Measures lung size (eg TLC, FRC, RV, ERV, IC). Lung volumes are useful for confirming restriction and identifying mixed ventilatory defects
• Bronchial Provocation Tests – May assist with diagnosis of asthma or assessment of effectiveness of asthma treatment. Mannitol Challenge is bronchial provocation test of choice for the vast majority of cases. We also provide Hypertonic saline and Mannitol for airway clearance
• The Alfred - Lung Function Laboratory - Mannitol Challenge
• The Alfred - Lung Function Laboratory - Hypertonic saline for airway clearance assessment
• The Alfred - Lung Function Laboratory - Inhaled Mannitol to Assist Airway Clearance
• Fraction of exhaled Nitric Oxide (FeNO) – May be useful in detecting current airway inflammation in those with eosinophilic asthma
• Cardiopulmonary Exercise Testing (stage 1) – Includes VO2, work, ventilation and heart rate. This is useful for patients with unexplained dyspnoea after other avenues to explain dyspnoea (cardiac / resting respiratory function) have been explored. Referrals for cardiopulmonary exercise tests are accepted from specialist physicians only. GPs: please contact the laboratory if a CPET is required
• The Alfred - Lung Function Laboratory - Cardiopulmonary Exercise Test (referral via medical specialist only)
• Hypoxic Altitude Simulation Test – Assessment of oxygen saturation at simulated altitude (equivalent to maximum cabin altitude of commercial aircraft). This is useful for patients with respiratory impairment who wish to fly. Note: the outcome of this test should not be used alone to determine fitness to fly
• Maximal respiratory pressures – Provides an indication of global respiratory muscle strength (inspiratory & expiratory)
• Assessment of vocal cord dysfunction is also available, but referral is via the Middle Airway Clinic, Asthma, Allergy and Clinical Immunology
• The Alfred - Lung Function Laboratory - Mannitol Challenge with Nasal Endoscope
• The Alfred - Lung Function Laboratory - Cardiopulmonary Exercise Test with Continuous Laryngoscopy

Relative Contraindications for Lung Function Tests

Most lung function tests require the patient to sit unaided and to follow specific instructions in the performance of breathing manoeuvres requiring maximal effort.

Patients with poor cognitive function will have difficulties performing tests.

Patients with limited English language skills may require an interpreter – please document on referral if an interpreter will be required.

There are few absolute contraindications for lung function tests. We may choose to delay or modify tests where there is an increased risk of an adverse event, or results may be impacted by pain/discomfort.

Examples include:

• Acute myocardial infarction in previous week
• Systemic hypotension or severe hypertension
• Significant atrial/ventricular arrhythmia
• Non-compressed heart failure
• Uncontrolled pulmonary hypertension
• Acute cor pulmonale
• Clinically unstable pulmonary embolism
• History of syncope associated with forced expiration/cough
• Cerebral aneurysm
• Brain surgery in previous 4 weeks
• Recent concussions with continuing symptoms
• Eye surgery in previous week
• Sinus surgery or middle ear surgery or infection in previous week
• Current pneumothorax
• Thoracic surgery in previous 4 weeks
• Abdominal surgery in previous 4 weeks
• Late-term pregnancy
• Current haemoptysis
• Rib fractures

Tests will be delayed where patients have communicable diseases such as:

• Open pulmonary TB (on active treatment and 3 negative AFB in sputum)
• Pertussis (>1 week antibiotic therapy)
• Influenza
• Gastroenteritis (> 48 hours after last symptoms)
• COVID
  • Close contact - wait 2 weeks
  • If immunocompetent - wait 2 weeks from positive RAT date
  • If immunocompromised – wait 20 days from positive test and require photographic evidence of negative RAT after 20 days
• RSV – wait minimum 5 days from symptom onset

Some tests require minimum levels of lung function for test to be performed:

• Vital capacity of at least 1.20L required for TLCO
• Baseline FEV1 >70% predicted or 1.5L AND good quality baseline spirometry for bronchial provocation tests

Please contact the Lung Function Laboratory on (03) 9076 3476 to discuss potential contraindications and/or document clearly on referral.

Exclusion criteria

Children under 18 years of age are not seen at The Alfred 

Clinic times