Spirometry, lung volumes
From WikiLectures
Spirometry consists of the measurement of lung ventilation, the values obtained are important in the management of artificial lung ventilation and in the diagnosis of lung diseases. Ventilation parameters are measured by spirometers. We divide the measured parameters into:
- Static – the size of the alveolar space → inform about possible restriction disorders.
- Dynamic – the record of airflow in the airways → inform about obstructive disorders.
Static volumes[edit | edit source]
Tidal Volume (TV)[edit | edit source]
- the amount of air that goes into the lungs with each inhalation (or the amount that is expelled with each exhalation);
- 0.5 l
Inspiratory Reserve Volume (IRV)[edit | edit source]
- air that is breathed in at maximal inspiratory effort above tidal volume;
- Men: 3 years
- Women: 2 yrs.
Expiratory reserve volume (ERV)[edit | edit source]
- volume expelled by active expiratory effort after passive expiration;
- Men: 1.2 l.
- Women: 0.7 l.
Vital Capacity (VC)[edit | edit source]
- the largest amount of air that can be exhaled after maximal inspiratory effort;
- it is often determined clinically as an index of lung function;
- Men: 5 l.
- Women: 3 yrs.
Dynamic volumes[edit | edit source]
Forced Expiratory Volume in one second (FEV1)[edit | edit source]
- the part of the vital capacity exhaled during the first second (also called the broken down vital capacity exhalation or forced expiratory volume in 1 s);
- it provides valuable information in diseases such as asthma, in which airway resistance is increased as a result of airway narrowing, vital capacity may be normal, but temporal vital capacity is significantly reduced.
Peak Expiratory Flow (PEF)[edit | edit source]
- 12 l/s.
Minute Pulmonary Ventilation - Respiratory Minute Volume (MPV, RMV)[edit | edit source]
- 6-8 liters/min (e.g. for 6 l – 500 ml/breath x 12 breaths/minute)
Maximum Free Ventilation (MFV)[edit | edit source]
- the largest volume of air that can be delivered to the lungs in one minute by voluntary effort;
- up to 200 liters/minute.
Cannot be measured by spirometry[edit | edit source]
Residual Volume (RV)[edit | edit source]
- air remaining in the lungs after maximum expiratory effort;
- 1.2 l;
- the dilution method is used for its measurement.
Dead volume (DV)[edit | edit source]
- the volume of air that does not participate in gas exchange;
- on exhalation, it mixes with alveolar air and cannot be distinguished;
- to determine, we must analyze the composition of exhaled air.
Links[edit | edit source]
Related articles[edit | edit source]
Source[edit | edit source]
- KITTNAR, Otomar, et al. Lékařská fyziologie. 1. edition. Grada Publishing, 2011. 800 pp. ISBN 978-80-247-3068-4.
- KYMPLOVÁ, Jaroslava. Katalog metod v biofyzice [online]. [cit. 2012-09-20]. <https://portal.lf1.cuni.cz/clanek-793-katalog-metod-v-biofyzice>.