What is a CPEX test?
A Cardiopulmonary Exercise Test (CPEX, also known as CPET) is a safe exercise test used to measure your fitness. It is the best test to measure how your heart and lungs will cope with surgery. It is a short exercise test on a static bicycle (like exercise bikes you see in gyms). Many hospitals offer it as part of your pre-operative assessment and planning for surgery.
Why do I need to have this test?
We do this test to find out how you are likely to react to surgery. This will inform surgeons and anaesthetists how best to look after you. This may reduce your risk of complications, and it will also provide useful information about your potential recovery time following the operation.
What happens during the test?
Before your test begins, staff will fully explain what will happen and answer any questions you may have. The test usually lasts between 5 and 12 minutes. Staff will ask you to tell them if you feel any discomfort or pain during the test. You are free to stop if you feel fatigued (tired) or uncomfortable; but the longer you can go, the better the information we will get.
Whilst cycling your breath will be analysed and your heart and blood pressure monitored. You will have some simple medical equipment attached to you so that we can take these readings. A specialised mask will measure the oxygen and carbon dioxide in your breath.
A health professional will be with you at all times. We may ask you to stop if we see you look fatigued or there are changes to your heart rate or blood pressure.
The test begins gently, with a low intensity cycle; you will feel no resistance as you pedal. Gradually you will feel increased resistance when pedaling. Most people do enough of the test for us to get the medical information we need. After the test, you rest on the bike until you are ready to sit down and discuss the results.
Occasionally, with your permission, we may include your anonymised results in research to improve patient care.
Important information
- Please continue to take all your medications as normal – or how you have been instructed by your doctor.
- Please do not wear nail varnish to your appointment.
Will I experience any discomfort or side effects?
There are no known side effects. CPEX testing is very safe. Rarely patients experience problems with abnormal blood pressure, irregular heart rates, or chest pain.
Complications happening during the test is actually a good thing. This identifies patients who will potentially have problems during surgery and minimises the risk of surgery that you are exposed to.
Every effort will be made to minimise any risk by evaluation of your medical information before the test, and careful observation during the test.
Is there a different test I could have?
There is no other test that provides this information about your heart and lung ‘fitness’.
When will I be told the results of my test?
You will be told of the results on the same day by the doctors performing the test. The information will also be shared with the doctor or surgeon who requested the test.
What if it tells me I cannot have my operation?
Sometimes the information will tell us that your body will find the stresses and strains of the operation too much. We will discuss the risks and benefits of the surgery with you and your surgeon.
I have bad joints and am worried about riding the bike?
Unless you have very severe joint pain, most people are able to ride the bike for the duration of the test.
How ‘fit’ do I have to be to perform the test?
People of all levels of ability, ages and fitness are able to perform the test.
I am worried or anxious about completing the test
We understand that many patients find the idea of this test worrying for many reasons. We have excellent staff at hand to reassure and support you through the process. Feel free to answer ask questions on the day. We will do our best to make you feel safe and well-cared for during your appointment.
What should I wear for my test?
You should wear normal comfortable clothing and flat shoes (ideally trainers) suitable for cycling in.
© North Bristol NHS Trust. This edition published October 2024. Review due October 2027. NBT002669
