Vital capacity
![](https://upload.wikimedia.org/wikipedia/commons/thumb/3/3b/Lungvolumes.svg/250px-Lungvolumes.svg.png)
Vital capacity(VC) is the maximum amount of air a person can expel from the lungs after a maximuminhalation.It is equal to the sum ofinspiratory reserve volume,tidal volume,andexpiratory reserve volume.It is approximately equal to Forced Vital Capacity (FVC).[1][2]
A person's vital capacity can be measured by a wet or regularspirometer.In combination with other physiological measurements, the vital capacity can help make a diagnosis of underlyinglung disease.Furthermore, the vital capacity is used to determine the severity of respiratory muscle involvement inneuromuscular disease,and can guide treatment decisions inGuillain–Barré syndromeandmyasthenic crisis.[citation needed]
A normal adult has a vital capacity between 3 and 5 litres.[3]A human's vital capacity depends on age, sex, height, mass, and possibly ethnicity.[4]However, the dependence on ethnicity is poorly understood or defined, as it was first established by studying blackslavesin the 19th century[5]and may be the result of conflation with environmental factors.[6]
Lung volumesand lung capacities refer to the volume of air associated with different phases of the respiratory cycle. Lung volumes are directly measured, whereas lung capacities are inferred from volumes.
Role in diagnosis
[edit]The vital capacity can be used to help differentiate causes of lung disease. Inrestrictive lung diseasethe vital capacity is decreased. Inobstructive lung diseaseit is usually normal or only slightly decreased.[7]
Estimated vital capacities
[edit]Height | 150–155 cm (4'11 "–5'1" ) | 155–160 cm (5'1 "–5'3" ) | 160–165 cm (5'3 "–5'5" ) | 165–170 cm (5'5 "–5'7" ) | 170–175 cm (5'7 "–5'9" ) | 175–180 cm (5'9 "–5'11) |
---|---|---|---|---|---|---|
Vital capacity (cm3) | 2900 | 3150 | 3400 | 3720 | 3950 | 4300 |
Age | 15–25 | 25–35 | 35–45 | 45–55 | 55–65 |
---|---|---|---|---|---|
Vital capacity (cm3) | 3425 | 3500 | 3225 | 3050 | 2850 |
Formulas
[edit]Vital capacity increases with height and decreases with age. Formulas to estimate vital capacity are:[3]
whereis approximate vital capacity in cm3,is age in years, andis height in cm.
References
[edit]- ^Chhabra, S. K. (January 1998). "Forced Vital Capacity, Slow Vital Capacity, or Inspiratory Vital Capacity: Which Is the Best Measure of Vital Capacity?".Journal of Asthma.35(4): 361–365.doi:10.3109/02770909809075669.PMID9669830.
- ^"Forced Expiratory Volume and Forced Vital Capacity".Michigan Medicine.
- ^ab"Vital Capacity".Family Practice Notebook.Retrieved19 February2015.
- ^Hutchinson, John (January 1846)."On the Capacity of the Lungs, and on the Respiratory Functions, with a View of Establishing a Precise and Easy Method of Detecting Disease by the Spirometer".Journal of the Royal Society of Medicine.MCT-29 (1): 137–252.doi:10.1177/095952874602900113.PMC2116876.PMID20895846.
- ^Villarosa, Linda (14 August 2019)."How False Beliefs in Physical Racial Difference Still Live in Medicine Today".The New York Times.
- ^Braun, Lundy (2015)."Race, ethnicity and lung function: A brief history".Canadian Journal of Respiratory Therapy.51(4): 99–101.PMC4631137.PMID26566381.
- ^"Pulmonary Function Tests".UCSD.Retrieved19 February2015.[dead link]
- ^abPratt, Joseph H. (December 1922)."Long-Continued Observations on the Vital Capacity in Health and Heart Disease".The American Journal of the Medical Sciences.164(6): 819–831.doi:10.1097/00000441-192212000-00003.S2CID71818743.ProQuest125233939.
Further reading
[edit]Several studies have been made to measure and predict vital capacity:
- Berglund, E.; Birath, G.; Bjure, J.; Grimby, G.; Kjellmer, I.; Sandqvist, L.; Söderholm, B. (1963). "Spirometric Studies in Normal Subjects I: Forced Expirograms in Subjects Between 7 and 70 Years of Age".Acta Medica Scandinavica.173(2): 185–192.doi:10.1111/j.0954-6820.1963.tb16520.x.PMID13970718.
- Birath, G.; Kjellmer, I.; Sandqvist, L. (1963). "Spirometric Studies in Normal Subjects: II. Ventilatory Capacity Tests in Adults".Acta Medica Scandinavica.173(2): 193–198.doi:10.1111/j.0954-6820.1963.tb16521.x.PMID13968399.
- Grimby, G.; Sóderholm, B. (1963). "Spirometric Studies in Normal Subjects: III. Static Lung Volumes and Maximum Voluntary Ventilation in Adults with a Note on Physical Fitness".Acta Medica Scandinavica.173(2): 199–206.doi:10.1111/j.0954-6820.1963.tb16523.x.
- Forche, Günther; Stadlober, Ernst; Harnoncourt, Karl (1988). "Neue spirometrische Bezugswerte für Kinder, Jugendliche und Erwachsene" [New spirometric reference values for children, adolescents and adults].Österreichische Ärztezeitung(in German).43(15, 16): 40–42.
- Gulsvik, A.; Tosteson, T.; Bakke, P.; Humerfelt, S.; Weiss, S. T.;Speizer, F. E.(30 November 2001). "Expiratory and inspiratory forced vital capacity and one-second forced volume in asymptomatic never-smokers in Norway: Spirometric standards in Norway".Clinical Physiology.21(6): 648–660.doi:10.1046/j.1365-2281.2001.00377.x.PMID11722472.
- Hedenström, H; Malmberg, P; Agarwal, K (November 1985). "Reference values for lung function tests in females. Regression equations with smoking variables".Bulletin Européen de Physiopathologie Respiratoire.21(6): 551–557.OCLC114155676.PMID4074961.INIST8470928.
- Langhammer, A.; Johnsen, R.; Gulsvik, A.; Holmen, T.L.; Bjermer, L. (1 November 2001)."Forced spirometry reference values for Norwegian adults: the Bronchial Obstruction in Nord-Trøndelag study".European Respiratory Journal.18(5): 770–779.doi:10.1183/09031936.01.00255301.PMID11757626.