VCI

FromtheBreathingCircuitSeriesClinicalFocusbyDatex-OhmedaVitalCapacityInductionAtechniqueforrapid,singlebreathinductionofinhalationanesthesiaGuestEditorJamesH.Philip,MEE,MDAnesthesiologist:BrighamandWomen’sHospital,Boston,MAAssociateProfessorofAnesthesia:HarvardMedicalSchool,Boston,MADatex-Ohmeda,Inc.P.O.Box7550,Madison,WI53707-7550,USATel.8003452700•[e-mail]sforadditionaleducationalmaterial•©2002Datex-Ohmeda,Inc.Allrightsreserved.Subjecttochangewithoutnotice.PrintedinUSA.Datex®,Ohmeda®andothertrademarksarepropertyofInstrumentariumCorp.oritssubsidiaries.Allotherproductandcompanynamesarepropertyoftheirrespectiveowners.ConclusionVCIisanalternativetoconventionalintravenousinductionsandmaybeadvantageousinchildrenandadults.Betterthanhalothane,sevofluraneiswelltoleratedinmostpatientsandisverywellsuitedtotheVCItechniqueInspiredconcentrationshouldbecontrolledandmeasuredduringVCI.Theentireanesthesiamachine,breathingsystem,andpatientcircuitmustbeconsideredwhendecidingontheFGF,time,andmethodthatwillbeusedtopreparethesystem.Combined,sevofluraneandVCIareanexcellentchoiceincertainclinicalsituations.Asalways,clinicalvigilanceisparamountinachievingthedesiredoutcome.VitalCapacityInductionsStudiesinthe1980sexploredtheabilityofhalothanetoproduceananestheticstaterapidly,withasinglebreath.Thistypeofsingle-breathinductionwascalledavitalcapacityinduction(VCI)becauseofthetechniqueusedtofillthelungsmaximallywithananestheticconcentrationofinhalationagent.ThisClinicalFocusClinicalFocusClinicalFocusClinicalFocusClinicalFocus,producedbytheDepartmentofClinicalAffairs,willdescribethisexcitingnewinductiontechnique.AVCIrequiresacooperativepatientwhoiscapableofperformingavitalcapacitybreathandwillthenholdthatbreath.Patientswhoarecandidatesmustbewillingtoperformthebreathwhenasked.Whilethiseliminatessomechildrenandsomeadults,itdoesallowmanytobenefitfromthetechnique.Patientsareinstructedtoexhalemaximallyandthenbreatheinasdeeplyaspossible.Thisisthevitalcapacitybreathandisheldaslongaspossible.SincetheearlyVCIinductionstudies,rapidinductionofinhalationanesthesiarequiredthattheanesthesiabreathingsystemcontainedthedesiredconcentrationoftheinhalationagentthatwouldinduceanesthe-sia.Whenthepatientwasaskedtoperformthevitalcapacitybreath,thegasesinhaledfromthesystemweresufficienttoproducegeneralanesthesia.SevofluraneandVCITheintroductionofsevofluranehasdrasticallychangedthepracticeofanesthesia.Asaninhalationinductionagentitisgrowinginpopularityowingtoitsuniquequalities,nottheleastofwhichistherelativeacceptabilityoftheagentevenathighconcentrations.ThisAdditionalreading:1.DoiM,IkedaK.Airwayirritationproducedbyvolatileanestheticsduringbriefinhalation:comparisonofhalothane,enflurane,isofluraneandsevoflurane.CanJAnaesth.1993;40:122-126.EpsteinRH,SteinAL,MarrAT,LessinJB.Highconcentrationversusincrementalinductionofanaesthesiawithsevofluraneinchildren:acomparisonofinductiontimes,vitalsignsandcomplications.JClinAnesth1998;10:41-52.GreenD,TownsendP,BagshawO,StokesM.Nodalrhythmandbradycardiaduringinhalationinductionwithsevofluraneininfants:acomparisonofincrementalandhigh-concentrationtechniques.Br.J.Anaesth.2000;85:368-3703.HallJ,StewartJ,HarmerM.Singlebreathinhalationinductionofsevofluraneanaesthesiawithandwithoutnitrousoxide:afeasibilitystudyinadultsandcomparisonwithanintravenousbolusofpropofol.Anaesthesia1997;52:410-415.4.PhilipBK,LombardLL,RoadER,DragerLR,CalalangI,PhilipJH.ComparisonofVitalCapacityInductionwithSevofluranetoIntravenousInductionwithPropofolforAdultAmbulatoryAnesthesia.AnesAnalg1999;89:623-627.5.RuffleJ,SniderM,RosenbergerJ,LattaW.Rapidinductionofhalothaneanaesthesiainman.Br.J.Anaesth1985;57:607-611.6.RuffleJ,SniderM.Comparisonofrapidandconventionalinductionsofhalothaneoxygenanaesthesiainhealthymenandwomen.Anesthesiology1987;67:584-587.7.SigstonPE,JenkinsAMC,JacksonEA,SuryMRJ,MackersieAM,HatchDJ.Rapidinhalationalinductioninchildren:8%sevofluranecomparedwith5%halothane.BrJAnaesth1997;78:362-5.8.WiltonN,ThomasV.Singlebreathinductionofanaesthesia,usingavitalcapacitybreathofhalothane,nitrousoxideandoxygen.Anaesthesia1986;41:472-476.9.YurinoM,KimuraH.Vitalcapacityrapidinhalationinductiontechnique:comparisonofsevofluraneandhalothane.CanJAnaesth1993;40:440-443.10.YurinoM,KimuraH.Acomparisonofvitalcapacitybreathandtidalbreathingtechniquesforinductionofanaesthesiawithhighsevofluraneconcentrationsinnitrousoxideandoxygen.Anaesthesia1995;50:308-311.qualityhasledtoarenewedinterestinVCIand,whencoupledwithlowsolubilityandhighvaporizationcapability,sevofluraneprovedmuchmoretolerableandreliableforthistypeofinhalationinduction,thoughcaremustbetakenasanyinductionmayproduceundesirableeffects.IndeedrecentstudiescomparingsevofluranetohalothaneforVCIhaveproventhevalueofboththistechniqueandsevofluraneforrapidinhalationinductions.VCIandbreathingcircuitsDuringthe1980smostanesthesiamachineswerequitesimilarandmosthadratherlargebreathingsystemandpatientcircu