Spirometry is used to detect any changes in lung function due to exposure to respiratory hazards in the workplace. Work related lung problems are caused by workplace exposure to glues, resins, grain dust, flour, wood dust, coal and silica, animals. The lungs can be permanently damaged and develop COPD (chronic obstructive pulmonary disease) fibrosis, and asthma. By monitoring lung function on a regular basis, it is possible to pick up trends and early changes to prevent more damaging conditions developing.
A lung function test looks at how well the lungs are working and can identify potential lung conditions if someone presents with wheeze, breathlessness or cough.
A respiratory questionnaire is completed prior to the lung function test to ensure the employee does not have any contraindications to performing the test. It also gives the occupational health nurse or doctor interpreting the results more information to make the correct diagnosis.
Risk Factors
Lung function tests should not be performed on the following people if they have had:
1. A recent heart attack.
2. Chest surgery
3. Eye surgery
4. Pulmonary embolism (blood clot in the lung)
5. Aortic aneurysm
The Assessment
Spirometry is a performed to examine how quickly you can empty air from your lungs.
You may be asked to wear a clip on your nose and sit on a chair.
You are asked to breathe in deeply and then slowly breathe out as far as you can gently into a mouthpiece.
You will then be asked to breathe is as much as you can, hold your breath for a few seconds and then breathe out as fast and hard as you can.
You will need to repeat this process at least three times as this gives more accurate results.
The test can take about 10 minutes.
It is advisable to wear loose clothing, avoid smoking for at least 1 hour prior to the test, avoid alcohol at least 4 hours before the test, avoid heavy physical exercise 30 minutes before the test. Check if any medication could interfere with the test results.
The Results
Following the test, a printout is produced with a graph. The results are measured against the predicted values. The clinician can then advise if you have any concerns about lung disease.
Spirometry measures 2 main factors, the forced expiratory vital capacity (FVC) and forced expiratory volume in 1 second (FEV1).
The ratio FEV1/ FVC can then be calculated.
FVC measurement >/=80% normal, <80% abnormal
FEV1 measurement >80% normal
FEV1/FVC is the percentage of your lung capacity you can exhale in 1 second.
The test is usually reviewed every 12 months.
