A spirometry is a test that assesses the function of the lungs.
A spirometry is performed to make a diagnosis or to follow-up lung disease.
Common lung diseases that can be diagnosed or followed with spirometry are:
- COPD (emphysema, chronic bronchitis)
- Cystic Fibrosis
- Restrictive lulng diseases
An experienced technician or physician can perform spirometry in children aged 3 or 4 years old. For less experienced technicians it is recommended not to perform spirometry testing before 7 or 8 years old.
The duration of a spirometry test is dependent of the cooperation of the test subject and the experience and coaching of the tester.
In perfect conditions the spirometry test can be performed in 5 minutes.
Spirometry should be performed at least once on all (ex-)smokers older than 40 years.
Other indications are:
- if the signs or history suggest a lung disease
- signs of lung damage on chest X-ray
- low oxygen saturation
- follow-up of known lung diseases
- detecting lung disease in people who come into professional contact with certain substances
Spirometry is not recommended in the following cases:
- hemoptysis (coughing up blood)
- pneumothorax (air between the lungs and the chest wall)
- cardiovascular disease such as recent infarction, pulmonary embolism, aneurysm, unstable cardiovascular status
- nausea or vomiting
- recent chest, abdomen, or eye surgery
Usually spirometry is not painfull. In rare case a transient headache or pain in the chest can occur.
Spirometry is harmless provided precautions are taken and do not blow if there is a contraindication.
Due to the forced maneuver, dizziness, mild headache, chest pain, coughing or syncope (fainting) can sometimes occur.
A major complication is a bronchospasm or asthma attack during the test. This is noticed when the successive tests give lower and lower one-second values and Tiffeneau indices and reproducibility is never achieved. If this occurs, the test should be discontinued and appropriate measures should be taken against the asthma attack.
The occurrence of this phenomenon is evidence of the presence of exercise-induced asthma.
the flow-volume loops are getting worse
after each blow: exercise induces asthme
(the red loop was the first, then the black one, then the blue one)
Other complications are extremely rare.
In principle, an acute respiratory infection is not a contraindication to performing a spirometry test, but the acute infection can affect the results. It is therefor rarely useful to perform a spirometry in this cases.