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{{Pulmonary function}}
{{Pulmonary function}}
The '''FEV1/FVC ratio''', also called Tiffeneau-Pinelli index, is a calculated ratio used in the diagnosis of [[obstructive lung disease|obstructive]] and [[restrictive lung disease]].<ref name="pmid18786983">{{cite journal |author=Swanney MP, Ruppel G, Enright PL, ''et al'' |title=Using the lower limit of normal for the FEV1/FVC ratio reduces the misclassification of airway obstruction |journal=Thorax |volume=63 |issue=12 |pages=1046–51 |year=2008 |month=December |pmid=18786983 |doi=10.1136/thx.2008.098483 |url=http://thorax.bmj.com/cgi/pmidlookup?view=long&pmid=18786983}}</ref><ref name="pmid8989055">{{cite journal |author=Sahebjami H, Gartside PS |title=Pulmonary function in obese subjects with a normal FEV1/FVC ratio |journal=Chest |volume=110 |issue=6 |pages=1425–9 |year=1996 |month=December |pmid=8989055 |doi= 10.1378/chest.110.6.1425|url=http://www.chestjournal.org/cgi/pmidlookup?view=long&pmid=8989055}}</ref> It represents the volume of air exhaled in the [[FEV1|first second]].<ref name="gp-training.net">http://www.gp-training.net/protocol/respiratory/copd/spirometry.htm</ref> See the Wikipedia article on [[spirometry]] for the definitions of FEV1 and FVC.
The '''FEV1/FVC ratio''', also called Tiffeneau-Pinelli<ref>Minelli R. Appunti dalle lezioni di fisiologia umana. La Goliardica Pavese, Pavia, 1992. </ref> index, is a calculated ratio used in the diagnosis of [[obstructive lung disease|obstructive]] and [[restrictive lung disease]].<ref name="pmid18786983">{{cite journal |author=Swanney MP, Ruppel G, Enright PL, ''et al'' |title=Using the lower limit of normal for the FEV1/FVC ratio reduces the misclassification of airway obstruction |journal=Thorax |volume=63 |issue=12 |pages=1046–51 |year=2008 |month=December |pmid=18786983 |doi=10.1136/thx.2008.098483 |url=http://thorax.bmj.com/cgi/pmidlookup?view=long&pmid=18786983}}</ref><ref name="pmid8989055">{{cite journal |author=Sahebjami H, Gartside PS |title=Pulmonary function in obese subjects with a normal FEV1/FVC ratio |journal=Chest |volume=110 |issue=6 |pages=1425–9 |year=1996 |month=December |pmid=8989055 |doi= 10.1378/chest.110.6.1425|url=http://www.chestjournal.org/cgi/pmidlookup?view=long&pmid=8989055}}</ref> It represents the volume of air exhaled in the [[FEV1|first second]].<ref name="gp-training.net">http://www.gp-training.net/protocol/respiratory/copd/spirometry.htm</ref> See the Wikipedia article on [[spirometry]] for the definitions of FEV1 and FVC.


Normal values are approximately 80%.<ref name="urlForced Expiration">{{cite web |url=http://oac.med.jhmi.edu/res_phys/Encyclopedia/ForcedExpiration/ForcedExpiration.HTML |title=Forced Expiration |work= |accessdate=2009-04-21}}</ref> Predicted normal values can be [http://www.dynamicmt.com/dataform3.html calculated online] and depend on age, sex, height, weight and ethnicity as well as the research study that they are based upon.
Normal values are approximately 80%.<ref name="urlForced Expiration">{{cite web |url=http://oac.med.jhmi.edu/res_phys/Encyclopedia/ForcedExpiration/ForcedExpiration.HTML |title=Forced Expiration |work= |accessdate=2009-04-21}}</ref> Predicted normal values can be [http://www.dynamicmt.com/dataform3.html calculated online] and depend on age, sex, height, weight and ethnicity as well as the research study that they are based upon.

Revision as of 19:39, 25 October 2012

TLCTotal lung capacity: the volume in the lungs at maximal inflation, the sum of VC and RV.
TVTidal volume: that volume of air moved into or out of the lungs in 1 breath (TV indicates a subdivision of the lung; when tidal volume is precisely measured, as in gas exchange calculation, the symbol TV or VT is used.)
RVResidual volume: the volume of air remaining in the lungs after a maximal exhalation
ERVExpiratory reserve volume: the maximal volume of air that can be exhaled from the end-expiratory position
IRVInspiratory reserve volume: the maximal volume that can be inhaled from the end-inspiratory level
ICInspiratory capacity: the sum of IRV and TV
IVCInspiratory vital capacity: the maximum volume of air inhaled from the point of maximum expiration
VCVital capacity: the volume of air breathed out after the deepest inhalation.
VTTidal volume: that volume of air moved into or out of the lungs during quiet breathing (VT indicates a subdivision of the lung; when tidal volume is precisely measured, as in gas exchange calculation, the symbol TV or VT is used.)
FRCFunctional residual capacity: the volume in the lungs at the end-expiratory position
RV/TLC%Residual volume expressed as percent of TLC
VAAlveolar gas volume
VLActual volume of the lung including the volume of the conducting airway.
FVCForced vital capacity: the determination of the vital capacity from a maximally forced expiratory effort
FEVtForced expiratory volume (time): a generic term indicating the volume of air exhaled under forced conditions in the first t seconds
FEV1Volume that has been exhaled at the end of the first second of forced expiration
FEFxForced expiratory flow related to some portion of the FVC curve; modifiers refer to amount of FVC already exhaled
FEFmaxThe maximum instantaneous flow achieved during a FVC maneuver
FIFForced inspiratory flow: (Specific measurement of the forced inspiratory curve is denoted by nomenclature analogous to that for the forced expiratory curve. For example, maximum inspiratory flow is denoted FIFmax. Unless otherwise specified, volume qualifiers indicate the volume inspired from RV at the point of measurement.)
PEFPeak expiratory flow: The highest forced expiratory flow measured with a peak flow meter
MVVMaximal voluntary ventilation: volume of air expired in a specified period during repetitive maximal effort

The FEV1/FVC ratio, also called Tiffeneau-Pinelli[1] index, is a calculated ratio used in the diagnosis of obstructive and restrictive lung disease.[2][3] It represents the volume of air exhaled in the first second.[4] See the Wikipedia article on spirometry for the definitions of FEV1 and FVC.

Normal values are approximately 80%.[5] Predicted normal values can be calculated online and depend on age, sex, height, weight and ethnicity as well as the research study that they are based upon.

A derived value of FEV1% is FEV1% predicted, which is defined as FEV1% of the patient divided by the average FEV1% in the population for any person of similar age, sex and body composition.

Disease states

In obstructive lung disease, the FEV1 is reduced due to an obstruction of air escaping from the lungs. Thus, the FEV1/FVC ratio will be reduced.[4] More specifically, the diagnosis of COPD is made when the FEV1/FVC ratio is less than 70%.[6] The Global Initiative for Obstructive Lung Disease (GOLD) criteria also require that values are after bronchodilator medication has been given to make the diagnosis. According to the European Respiratory Society (ERS) criteria, it is FEV1% predicted that defines when a patient has COPD--that is, when the patient's FEV1% is less than 88% of the predicted value for men, or less than 89% for women.[6].

In restrictive lung disease, the FEV1 and FVC are equally reduced due to fibrosis or other lung pathology (not obstructive pathology). Thus, the FEV1/FVC ratio should be approximately normal, or even increased due to an increased FEV1 value (because of the decreased compliance associated with the presence of fibrosis in some pathological conditions).[4]

References

  1. ^ Minelli R. Appunti dalle lezioni di fisiologia umana. La Goliardica Pavese, Pavia, 1992.
  2. ^ Swanney MP, Ruppel G, Enright PL; et al. (2008). "Using the lower limit of normal for the FEV1/FVC ratio reduces the misclassification of airway obstruction". Thorax. 63 (12): 1046–51. doi:10.1136/thx.2008.098483. PMID 18786983. {{cite journal}}: Explicit use of et al. in: |author= (help); Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)
  3. ^ Sahebjami H, Gartside PS (1996). "Pulmonary function in obese subjects with a normal FEV1/FVC ratio". Chest. 110 (6): 1425–9. doi:10.1378/chest.110.6.1425. PMID 8989055. {{cite journal}}: Unknown parameter |month= ignored (help)
  4. ^ a b c http://www.gp-training.net/protocol/respiratory/copd/spirometry.htm
  5. ^ "Forced Expiration". Retrieved 2009-04-21.
  6. ^ a b Attention: This template ({{cite doi}}) is deprecated. To cite the publication identified by doi:10.1186/1465-9921-8-89, please use {{cite journal}} (if it was published in a bona fide academic journal, otherwise {{cite report}} with |doi=10.1186/1465-9921-8-89 instead. [1]
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