（推荐课件）高流量氧疗的生理效应

高流量氧疗的生理效应,PhysiologicalEffectofHighFlowNasalCannula(HFNC)Therapy,1,COIstatement,Theauthorhasnoconflictofinteresttodeclare.,2,HighFlow,aninterestingoxygenationmethod,-novel-magic-gentleandmoderate,Socool,3,HFNCshinesduringRSI,Putthebigcannulaeintoyourpatientsnoseandletrrip.AddafacemaskorNIVorwhateveryourpreoxygenationpleasure,thenpushyourmedsandlaughtoyourselfasthesaturationrisesduringapnea.Whistlesweetlyastheinternilluminateseveryinchofthesoftpalatewithgreatdetermination.Hell,goseeanotherpatientandtellhimtocallyouwhenhesgivenup.,Youremember,though,thedaysofthegiants.Whenbeingregardedasaskilledlaryngoscopistmeantsomething.Whenthewordairwaymadeinternistsscatterlikemice.Whenitwasntsoeasytosavealife.,4,Pediatricianhaspromotedoxygentherapy,5,Oxygentherapy4(2):215-28,16,Temperatureandhumidity,Lowtemperaturedoesmeaninsufficienthumidity.Enoughwatersupplementdoesnotalwaysmeansufficienthumidity.Anadultmayrequireapproximately150calories/min(10kcal/h)forconditioninginspiratoryairfromambienttoBTS.,KacmarekRM,etal.EgansFundamentalsofRespiratoryCare.St.Louis,MO:Elsevier/Mosby,2013.,17,Inspiredgasneedsconditioning,Respirationwithambientgas,notwarmedorhumidified,inducedbronchoconstrictionresponse,andresultedinasignificantdecreaseinbothpulmonarycompliance.ThenasalairpassagesexpendquiteafewenergytowarmandhumidityinspiratoryairfromambienttoBTS.Studiesfromthe1990sdemonstratedthenegativeeffectsofusingnon-warmed,non-humidifiedgastosupportrespiration.,18,FlowandPressurefundamentals,HFNCisintendedtobeanopensystem,withflowdeliveredtoapatientvianasalcannula,wherethecannulaprongsdonotoccludethenaresandwherethepatientsmouthisnotheldclosed.Inthisopensystem,thepressureineachcompartmentisafunctionoftheresistor(s)thatlieinseriesdownstreamfromthatcompartment.Inthisregard,circuitpressureswillalwaysbesubstantiallygreaterthanpressureinthenasopharynx.,19,Factorsdeterminnasopharyngealpressure,theflowsettingthepatientsuniqueanatomicaldimensionstheleakoutofthenosearoundtheprongsandoutofthemouth(ODofcannulaprongvs.IDofnares),20,MechanismsofAction:HFNCDiffersfromCPAP,MndelTetal.MechanismsofnasalhighowonventilationduringwakefulnessandsleepJApplPhysiol,2013.114:10581065,21,EffectsofflowonairwaypressureduringHFNC,Higherflowratecreateshigherairwaypressure.Pressureisdifferentwhenmouthclosedoropen.Onlymoderatepositiveairwaypressure(10cmH2O)canbegeneratedbyHFNC.,ParkeR,etal.RespirCare2011;56(8):11511155.,22,PositiveairwaypressureisnottheprinciplemechanismofHFNC,Thebasicflowsettingismeantfundamentallytoexceednormalinspiratoryflowratessoastoeliminateentrainmentofroomair,andenhancenasopharyngealwashouteffects.Excessiveflowsinanattempttogeneratesubstantialdistendingpressuresshouldnotbeutilized.Toaccomplishtheactionsofdeadspacewashout,selectingnasalprongsshouldhaveanoutsided