FEV1/FVC ratio - Wikipedia

It represents the proportion of a person's vital capacity that they are able to expire in the first second of forced expiration (FEV1) to the full, forced vital ... FEV1/FVCratio FromWikipedia,thefreeencyclopedia Jumptonavigation Jumptosearch Ratiousedinthediagnosisoflungdisease TLCTotallungcapacity:thevolumeinthelungsatmaximalinflation,thesumofVCandRV.TVTidalvolume:thatvolumeofairmovedintooroutofthelungsduringquietbreathing(TVindicatesasubdivisionofthelung;whentidalvolumeispreciselymeasured,asingasexchangecalculation,thesymbolTVorVTisused.)RVResidualvolume:thevolumeofairremaininginthelungsafteramaximalexhalationERVExpiratoryreservevolume:themaximalvolumeofairthatcanbeexhaledfromtheend-expiratorypositionIRVInspiratoryreservevolume:themaximalvolumethatcanbeinhaledfromtheend-inspiratorylevelICInspiratorycapacity:thesumofIRVandTVIVCInspiratoryvitalcapacity:themaximumvolumeofairinhaledfromthepointofmaximumexpirationVCVitalcapacity:thevolumeofairbreathedoutafterthedeepestinhalation.VTTidalvolume:thatvolumeofairmovedintooroutofthelungsduringquietbreathing(VTindicatesasubdivisionofthelung;whentidalvolumeispreciselymeasured,asingasexchangecalculation,thesymbolTVorVTisused.)FRCFunctionalresidualcapacity:thevolumeinthelungsattheend-expiratorypositionRV/TLC%ResidualvolumeexpressedaspercentofTLCVAAlveolargasvolumeVLActualvolumeofthelungincludingthevolumeoftheconductingairway.FVCForcedvitalcapacity:thedeterminationofthevitalcapacityfromamaximallyforcedexpiratoryeffortFEVtForcedexpiratoryvolume(time):agenerictermindicatingthevolumeofairexhaledunderforcedconditionsinthefirsttsecondsFEV1VolumethathasbeenexhaledattheendofthefirstsecondofforcedexpirationFEFxForcedexpiratoryflowrelatedtosomeportionoftheFVCcurve;modifiersrefertoamountofFVCalreadyexhaledFEFmaxThemaximuminstantaneousflowachievedduringaFVCmaneuverFIFForcedinspiratoryflow:(Specificmeasurementoftheforcedinspiratorycurveisdenotedbynomenclatureanalogoustothatfortheforcedexpiratorycurve.Forexample,maximuminspiratoryflowisdenotedFIFmax.Unlessotherwisespecified,volumequalifiersindicatethevolumeinspiredfromRVatthepointofmeasurement.)PEFPeakexpiratoryflow:ThehighestforcedexpiratoryflowmeasuredwithapeakflowmeterMVVMaximalvoluntaryventilation:volumeofairexpiredinaspecifiedperiodduringrepetitivemaximaleffortvte TheFEV1/FVCratio,alsocalledTiffeneau-Pinelliindex,[1]isacalculatedratiousedinthediagnosisofobstructiveandrestrictivelungdisease.[2][3]Itrepresentstheproportionofaperson'svitalcapacitythattheyareabletoexpireinthefirstsecondofforcedexpiration(FEV1)tothefull,forcedvitalcapacity(FVC).[4]TheresultofthisratioisexpressedasFEV1%. Normalvaluesareapproximately75%.[5]Predictednormalvaluescanbecalculatedonlineanddependonage,sex,height,andethnicityaswellastheresearchstudythattheyarebasedupon. AderivedvalueofFEV1%isFEV1%predicted,whichisdefinedasFEV1%ofthepatientdividedbytheaverageFEV1%inthepopulationforanypersonofsimilarage,sex,andbodycomposition. Diseasestates[edit] Inobstructivelungdisease,theFEV1isreducedduetoanobstructionofairescapingfromthelungs.Thus,theFEV1/FVCratiowillbereduced.[4]Morespecifically,accordingtotheNationalInstituteforClinicalExcellence,thediagnosisofCOPDismadewhentheFEV1/FVCratioislessthan0.7or[6]theFEV1islessthan75%ofpredicted;[7]however,otherauthoritativebodieshavedifferentdiagnosticcutoffpoints.[8]TheGlobalInitiativeforChronicObstructiveLungDiseasecriteriaalsorequirethatvaluesareafterbronchodilatormedicationhasbeengiventomakethediagnosis.AccordingtotheEuropeanRespiratorySociety(ERS)criteria,itisFEV1%predictedthatdefineswhenapatienthasCOPD—thatis,whenthepatient'sFEV1%islessthan88%ofthepredictedvalueformen,orlessthan89%forwomen.[8] Inrestrictivelungdisease,theFEV1andFVCareequallyreducedduetofibrosisorotherlungpathology(notobstructivepathology).Thus,theFEV1/FVCratioshouldbeapproximatelynormal,orevenincreasedduetoadecreaseinmagnitudeofFVCascomparedtoFEV1(becauseofthedecreasedcomplianceassociatedwiththepresenceoffibrosisinsomepathologicalconditions).[4] References[edit] ^MinelliR.Appuntidallelezionidifisiologiaumana.LaGoliardicaPavese,Pavia,1992. ^SwanneyMP,RuppelG,EnrightPL,et al.(2008)."UsingthelowerlimitofnormalfortheFEV1/FVCratioreducesthemisclassificationofairwayobstruction".Thorax.63(12):1046–51.doi:10.1136/thx.2008.098483.PMID 18786983. ^SahebjamiH,GartsidePS(1996)."PulmonaryfunctioninobesesubjectswithanormalFEV1/FVCratio"(PDF).Chest.110(6):1425–9.doi:10.1378/chest.110.6.1425.PMID 8989055.Archivedfromtheoriginal(PDF)on2019-02-19. ^abcInterpretingspirometryArchived2008-07-25attheWaybackMachine.gp-training.net ^"ForcedExpiration".JohnsHopkinsUniversity. ^Chronicobstructivepulmonarydisease:Managementofchronicobstructivepulmonarydiseaseinadultsinprimaryandsecondarycare(partialupdate).NICE.org.uk.June2010 ^Chronicobstructivepulmonarydisease:Managementofchronicobstructivepulmonarydiseaseinadultsinprimaryandsecondarycare(partialupdate).NICE.org.uk.June2010 ^abNathell,L.;Nathell,M.;Malmberg,P.;Larsson,K.(2007)."COPDdiagnosisrelatedtodifferentguidelinesandspirometrytechniques".RespiratoryResearch.8(1):89.doi:10.1186/1465-9921-8-89.PMC 2217523.PMID 18053200. vteRespiratoryphysiologyRespiration breath inhalation exhalation obligatenasalbreathing respiratoryrate respirometer pulmonarysurfactant compliance elasticrecoil hysteresivity airwayresistance bronchial hyperresponsiveness constriction dilatation mechanicalventilation Control pons pneumotaxiccenter apneusticcenter medulla dorsalrespiratorygroup ventralrespiratorygroup chemoreceptors central peripheral pulmonarystretchreceptors Hering–Breuerreflex Lungvolumes VC FRC Vt deadspace CC PEF calculations respiratoryminutevolume FEV1/FVCratio Lungfunctiontests spirometry bodyplethysmography peakflowmeter nitrogenwashout Circulation pulmonarycirculation hypoxicpulmonaryvasoconstriction pulmonaryshunt Interactions ventilation(V) Perfusion(Q) Ventilation/perfusionratio V/Qscan zonesofthelung gasexchange pulmonarygaspressures alveolargasequation alveolar–arterialgradient hemoglobin oxygen–hemoglobindissociationcurve(Oxygensaturation 2,3-BPG Bohreffect Haldaneeffect) carbonicanhydrase(chlorideshift) oxyhemoglobin respiratoryquotient arterialbloodgas diffusioncapacity(DLCO) Insufficiency highaltitude deathzone oxygentoxicity hypoxia Retrievedfrom"https://en.wikipedia.org/w/index.php?title=FEV1/FVC_ratio&oldid=1042970447" Categories:RespiratorytherapyRespiratoryphysiologyHiddencategories:WebarchivetemplatewaybacklinksArticleswithshortdescriptionShortdescriptionmatchesWikidata Navigationmenu Personaltools NotloggedinTalkContributionsCreateaccountLogin Namespaces ArticleTalk English Views ReadEditViewhistory More Search Navigation MainpageContentsCurrenteventsRandomarticleAboutWikipediaContactusDonate Contribute HelpLearntoeditCommunityportalRecentchangesUploadfile Tools WhatlinkshereRelatedchangesUploadfileSpecialpagesPermanentlinkPageinformationCitethispageWikidataitem Print/export DownloadasPDFPrintableversion Languages EspañolFrançaisItaliano日本語Polski Editlinks