How to properly use a spirometer for accurate results

If you suffer from chronic lung diseases, such as asthma, COPD or interstitial pulmonary fibrosis, you may be already familiar with spirometry, i.e. pulmonary function tests that help you measure your breathing capacity.

Lung function tests are fairly easy to perform, noninvasive and sensitive to early change, but do you really know how to use a spirometer for accurate results? Here are a few tips to get the best from your spirometer.

1. Learn to use your spirometer: understanding the parameters

Spirometers can be used to measure and track several different parameters related to your pulmonary capacity and function. Here are some of the most common:

• FEV1: Forced expiratory volume in 1 second.
• FVC: Forced vital capacity, i.e. the amount of air that a patient can exhale by blowing out as fast as possible.
• VC: Vital capacity, i.e. the amount of air that can be exhaled by blowing out at a steady rate.
• FEV1/FVC ratio.
• PEF: Peak Expiratory Fow, i.e. the maximal flow that a patient can exhale by blowing out as fast as possible.
• IVC: Inspiratory vital capacity, i.e. the amount of air that can be inhaled after a full expiration.

To get reliable measurements, it is important to know how to conduct yourself during the tests. Here are our recommendations on how to properly use a spirometer for accurate results.

1. Before you start: what to check
2. Make sure your spirometer is properly calibrated. This should be done by a professional, as flow can be quite difficult to calibrate and precise calculations are required. Long-term calibration is a feature you should look for when purchasing a home-use spirometer.
3. Check if the app is connected. When using a smart spirometer, such as MIR Spirobank Smart Spirometer, it will be necessary to install a specific app on your phone or tablet, connect it via Bluetooth to the device and fill in your personal data – age, height, body weight etc. – for accurate anamnesis and follow-up.
4. No room for infection! You don’t want infection to spread out, so remember to wash your hands and sterilize or replace used philters.
5. 3 steps to properly use a spirometer for accurate results
6. 1. Check your posture

Though lung tests are usually performed when seated – as you may get dizzy or light-headed from deep breathing – in order to get accurate results, there should be no difference in the amount of air you can breathe when standing Vs when sitting. Here is how to position yourself:

• Sit upright, with your back straight.
• Don’t cross your legs and keep your feet flat on the floor. Make sure there is no abdominal tension deriving from your leg position, as it may affect how the diaphragm works.
• Loosen your clothes, so that you don’t feel any restrictions.

1. 2. Take a few normal breaths

Before starting the test, take a few breaths to accustom yourself to your own tidal breathing. If you are a smoker, it is advisable to avoid cigarettes for at least an hour before taking the test.

1. 3. How to inhale/exhale

In order to measure FVC and FEV1 you will need to inhale as deeply as you can and then quickly expire all of the air you got in.

It is necessary to tightly position your mouth on the mouthpiece, so that no air can escape. To do so, you can either inspire with your lips already on the mouthpiece or you can position your mouth as quickly as possible right before the expiration, so long as you are able to place it tightly on the mouthpiece.

In order to get consistent results, the test should be repeated two or three times, with a 10-15 minutes wait between each set of measurements.

1. Where to get an accurate spirometer for your tests

With over 30 years of experience, MIR is a world-renowned company in the medical-technological field. With several different solutions for the diagnosis of respiratory diseases in professional diagnostic, primary care, personal care and clinical trials, MIR products are available in more than 100 countries.