What is a Lung Function Test?

We use computerised spirometers to carry out a lung function test (also called spirometry or pulmonary function tests). Spirometry measures how much and how quickly you can move air out of your lungs. For this test, you breathe into a mouthpiece attached to the spirometer.

The more common lung function values measured with spirometry are:

• Forced vital capacity (FVC). This measures the amount of air you can exhale with force after you inhale as deeply as possible.


• Forced expiratory volume (FEV). This measures the amount of air you can exhale with force in one breath. The amount of air you exhale may be measured at 1 second (FEV1), 2 seconds (FEV2), or 3 seconds (FEV3). FEV1 divided by FVC can also be determined.
  
• Forced expiratory flow 25% to 75%. This measures the air flow halfway through an exhale.
  
• Peak expiratory flow (PEF). This measures how quickly you can exhale. It is usually measured at the same time as your forced vital capacity (FVC).

The full assessment entails completion of a health questionnaire and a lung function test.
Employees undergoing this testing will require periodic reviews, the frequency of which will depend on risk, clinical need and HSE guidelines. Employees that are identified as having new or worsening symptoms may require referral to an Occupational Health Physician.