高流量氧疗的生理效应

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1、高流量氧疗的生理效应高流量氧疗的生理效应PhysiologicalEffectofHighFlowNasalCannula(HFNC)TherapyCOIstatementTheauthorhasnoconflictofinteresttodeclare.HighFlowaninterestingoxygenationmethodnovelmagicgentleandmoderateHFNCshinesduringRSIPutthebigcannulaeintoyourpatientsnoseandletrrip.AddafacemaskorNIVorwhateveryourpreoxygen

2、ationpleasure,thenpushyourmedsandlaughtoyourselfasthesaturationrisesduringapnea.Whistlesweetlyastheinternilluminateseveryinchofthesoftpalatewithgreatdetermination.Hell,goseeanotherpatientandtellhimtocallyouwhenhesgivenup.Youremember,though,thedaysofthegiants.Whenbeingregardedasaskilledlaryngoscopist

3、meantsomething.Whenthewordairwaymadeinternistsscatterlikemice.Whenitwasntsoeasytosavealife.http:/ therapylair/oxygenappliedtopatientathigh flowrateslair/oxygenrunthroughanasal cannulalair/oxygeniswellconditionedbysufficientwarmthandhumidification socalledheated,humidifiedhigh-flownasalcannula(HHHFNC

4、)therapy2-70L/minMechanismsofactionforHFNClWashoutofnasopharyngealdeadspacelReductionofinspiratoryresistance(workofbreathing)byprovidingadequateflowlImprovedmechanicsbysupplyingadequatelywarmedandhumidifiedgaslReductioninthemetaboliccostofgasconditioninglProvisionofdistendingpressureWashoutofnasopha

5、ryngealdeadspaceThehigh volumetric flowspouringfromasmallborecannulacausehigh velocityflowswhichcreateturbulentenergytoflush the upper airwayofexpiratorygas.Deadspacewashoutimprovesventilationlanatomicaldeadspaceinadults30%oftidalvolumeinneonates50%oftidalvolumelchangethegascompositioninnasopharynge

6、alspacelreducerebreathingexpiredCO2lincreasethefractionofinspiredO2lincreasealveolarventilationefficiencyMV=(VTVD)xRRPaCO2=PeCO2/(1VD/VT)PaO2=(PBO2PH2O)xFiO2PaCO2/RPA-aO2CO2washoutduringHFNCwithdifferentflowratesNHFrates0L/min30L/min60L/minMidwaythroughexpiration(t=1.2s)Endofexpiration(t=2.2s)VanHov

7、eSC,etal.AnnBiomedEng(2016)44:3007-3019.HighflowandhighvelocityincreasealveolarventilationefficiencyllikelyminimizetheinspiratoryresistanceassociatedwiththenasopharynxbyprovidingnasopharyngealgasflowsthatmatchorexceedapatientspeakinspiratoryflowlCoandaeffectoccuringinthenasopharyngealregionduringexp

8、irationpotentiallyassistexpiratoryeffortslbringaboutadecreaseinworkofbreathingandrespiratoryratelcreatemoreturbulentenergyformoreeffectivewashoutlflushtheexpiratorygasfromtheupperairwayquicklyduringtheexhalationphaseofbreathing,whichiscriticalinpatientswithrapidbreathingVentilatoryResponsestoHFNCMndelTetal.MechanismsofnasalhighflowonventilationduringwakefulnessandsleepJApplPhysiol,2013.114:10581065MucociliarytransportsystemHealthciliatedepitheliumDamagedciliatedepitheliumhttps:/