A full lung function test will consist of a combination of Spirometry, Single Breath Gas Transfer and Body Plethysmography.
Spirometry
What is it?
Spirometry is an assessment of the airflow through the airways of the lung.
How to prepare for the test?
Unless specified you should take your regular medication as normal. For some assessments you may be asked to withhold your inhalers, as these can influence the results. One particular test is an assessment of how you perform spirometry pre and post inhaler. This is called reversibility.
What is involved?
For spirometry you will be asked to breathe normally on the mouthpiece with a peg on your nose. The physiologist will ask you to take a nice fast deep breath in till you are full. Then, you will immediately blow out the air as hard and fast as you can until you are empty and not able to blow any more. Finally, you take a big fast deep breath in to full.
Single Breath Gas Transfer
What is it?
Single breath gas transfer assesses how well oxygen gets from your lungs into the blood.
How to prepare for the test?
Prior to testing you will need to avoid smoking, vigorous exercise, large meals and alcohol consumption as these can influence the results. If you have had a full blood count taken in the last month at your GP or other health care provider, please tell the physiologist so they can look at the results.
What is involved?
For single breath gas transfer you will be asked to breathe normally on the mouthpiece, with your lips creating a tight seal and a peg on your nose. Firstly, you will blow all the air out of your lungs to empty, asked to take a breath in to as full as you can and hold for up to 10 seconds. Then you blow everything out whilst keeping your lips tight throughout.
Body Plethysmography
What is it?
Body plethysmography is used to assess the total amount of air inside your lungs. This comprises of the amount that you can breathe in and out, and the amount left inside the lungs when you have blown everything out.
How to prepare for the test?
The test is performed inside a cubicle with a chair, which is a similar size to a telephone box. If you suffer from claustrophobia please inform the physiologist before testing.
What is involved?
You will sit in the cubicle with the door closed for a minute while the temperature settles. The door is not locked and can be opened at anytime, if required. We will then ask you to breathe slightly quicker than normal on the mouthpiece, whilst holding your cheeks and with a peg on your nose. After 30 seconds to a minute a shutter will block off the mouthpiece for 2 seconds, during which time you need to pant against it. When the shutter opens you will be asked to breathe in to full, and then blow all the way out to empty like a sigh, with a final big breath in back to full.
What happens after the test?
When the tests have been completed a report will be generated and sent through for your consultant to review