麻醉科R楊美惠

麻醉科R楊美惠第1頁/共31頁DifferentwaystoreducetheincidenceoflaryngospasminchildrenafterTonsillectomyandAdenoidectomy第2頁/共31頁LaryngospasmMayinducedbybloodorsecretionaccumulatedaroundpharyhxoranykindofstimulationduringemergenceItisparticularlyfrequentinchildrenafterupperairwysurgery(e.g.adenotonsillectomy)

~about21-24%Laryngospasmisessentiallyaprotectivereflexwhichactstopreventforeignmaterialenteringthetracheaobronchialtree.Thisglotticreflextoinspirationandexpirationcauseshypercarbiaandhypoxiaandmaybelife-threatening.第3頁/共31頁CurrentmethodsDeepversusawakeextubationIVoraerosolizedlidocaineIVmagnesium“NoTouch”extubation第4頁/共31頁Emergenceairwaycomplicationsinchildren:acomparisonoftrachealextubationinawakeanddeeplyanesthetizedpatients.

AnesthAnalgPatelRI,HannallahRS,NordenJ,etal.1991;73:266-70

Patients:70childrenundergoingeitherelectivestrabismussurgeryoradenoidectomyand/ortonsillectomy.Methods:

Awakeextubationgroup:

Extubationatend-tidalhalothaneconcentrationsoflessthan0.15%

Deepextubationgroup:

end-tidalhalothaneconcentrationsofgreaterthan0.8%第5頁/共31頁Results:At1,2,3,and5minafterextubation,patientsextubateddeephadsignificantlyhigheroxyhemoglobinsaturationsthanpatientsextubatedawake(SpO297.6%+/-3.7%to99.8%+/-0.5%vs93.7%+/-4.8%to98.6%+/-2.5%).Oxygensaturationvaluesweresimilarthereafter.Theincidenceofpostoperativelaryngospasm,excessivecoughing,breathholding,airwayobstructionrequiringpositivepressureventilationafterextubation,orarrhythmiaswasnotstatisticallydifferentbetweenpatientsextubatedawakeordeep.第6頁/共31頁Theseinvestigatorsconcludedthatforhealthychildrenundergoingelectivesurgery,clinicalconditionsorthepreferenceoftheanesthesiologistshoulddictatethechoiceofextubationtechnique.第7頁/共31頁DeepextubationAdvantagesLesslikelytocoughandstrainafterward,thusavoidingthelikelihoodoflaryngospasmandoxygendesaturation.DisadvantagesRiskofaspirationandinadequateairwayprotection.第8頁/共31頁LidocaineviaIVrouteBarakaA.Intravenouslidocainecontrolsextubationlaryngospasminchildren.AnesthAnalg1978;57:506-7.Studygroup:receivinganIVbolusof2mg/kgoflidocaine1minpriortoextubation

Controlgroup:receivingnolidocainebeforeextubationResults:

Studygroup:noonedevelopedlaryngospasm

Controlgroup:4of20(20%)patientshadsevere laryngospasmafterextubation.第9頁/共31頁Doesintravenouslidocainepreventlaryngospasmafterextubationinchildren?

LeichtP,WisborgT,Chraemmer-JorgensenB.AnesthAnalg1985;64:1193-6.

Theincidenceoflaryngospasmwasthesamebetweenlidocaineandsalinegroups.TheyconcludedthattheirresultsdifferedfromBaraka'sbecauseofdifferencesinthetimeintervaltime(4.5vs0.5to1.5min)betweenlidocaineadministrationandextubation,andthatthecentraleffectoflidocainehadalreadydissipated（消散、消失）inthechildrentheyevaluated.

Thedurationofactionoflidocaineissuchthatitshouldbeadministered60-90spriortotrachealstimulationorextubation.

第10頁/共31頁LidocaineviaaerosolizedformDainDS,BousheyHA,GoldWM.Inhibitionofrespiratoryreflexesbylocalanestheticaerosolsindogsandrabbits.JApplPhysiol1975;38:1045-50.CrossBA,GuzA,JainSK,etal.Theeffectofanaesthesiaoftheairwayindogandman:astudyofrespiratoryreflexes,sensationsandlungmechanics.ClinSciMolMed1976;50:439-54.Commonconclusions:theinhalationofnebulized20%lidocaineor5%bupivacainehasbeenshowntoabolish（廢除、廢止）thecoughreflexinanimalsCrossetal.foundthatinhaledaerosolizedbupivacainesignificantlysuppressedcoughingtriggeredbyinhaledcitricacidortactilestimulationofthetracheawithasuctioncatheterviatracheotomystomas.第11頁/共31頁Localanesthetics,administeredeithersystemicallyorasaerosols,canalsoattenuatebronchospasmbydirectlyrelaxingairwaysmoothmuscle,inhibitingmediatorrelease,and/orinterruptingreflexarcs第12頁/共31頁Theuseofmagnesiumtopreventlaryngospasmaftertonsillectomyandadenoidectomy:apreliminarystudyGulhasN,DurmusM,DemirbilekS,etalPaediatrAnasth2003;13:43-7第13頁/共31頁Methods40patients,ASAI-II,aged3-12yearswerescheduledfortonsillectomyor/andadenoidectomy,inadouble-blindrandomized,prospectivemanner.Anesthesiacourse:

Inductionwithsevoflurane

Pre-intubationmedication:

Lidocaine1ml/kg,Alfentanil10ug/kg,Vecronium0.1mg/kg

Maintenance:sevofluranceandN2O第14頁/共31頁Twominutesafterintubation,ingroupI,patientsreceivedaninfusionofmagnesiumsulphate15mg/kgin30ml0.9%NaClfor20min.IngroupII,patientsreceivedonlythesameamountof0.9%NaCl.Fiveminutesbeforeextubation,bloodsamplesfromchildrenwerecollectedtoassessplasmamagnesiumconcentrations.第15頁/共31頁ExtubationcriteriaAnalgesiawithparacentamoladministeredrectallyAdequatespontaneousrespiratoryfunctionwasreestablished(VT>5ml/kg,respiratoryrate>12breath/min)andcompleteclearanceofbloodandsecretions.Extubationatdeepplaneofanaesthesia.第16頁/共31頁Results第17頁/共31頁第18頁/共31頁CharacteristicsofMagnesiumApredominantlyintracellularcationAnimportantcofactorinmanyenzymaticreactionsTwotheoryofmagnesiumactiononCNS:CNSdepressant

or(Co)analgesiceffectifusedasasupplementtoGA.-Thehaemodynamicandneurologicalchangesobservedafteradministrationofmagnesiumsuggestthatithasnodirectgeneralanaestheticproperties,butcausesasleep-likestateduetocerebralhypoxiafromprogressiverespiratoryandcardiacdepression.

-MagnesiumalsopoorlypenetratestheBBB.第19頁/共31頁Ifanappropriatedepthofanesthesiacanbeusedasaprecautiontopreventlaryngospasm,theeffectsofmagnesiumtoincreaseanestheticdepthmayberesponsible.第20頁/共31頁Anothermajoreffectofmagnesiumismusclerelaxationviathreemechanisms:CalciumantagonistPartialorcompleteimpedanceofmuscleendplatedepolarizationbydecreasingAchreleasedfromnerveendingpossibly.Changemembranetransportmechanismlikelocalanesthetics第21頁/共31頁TheIncidenceofLaryngospasmwitha“NoTouch”ExtubationTechniqueAfterTonsillectomyandAdenoidectomyBanC.H.Tsui,Wagner,CaveAnesthAnalg2004;98:327-9第22頁/共31頁BackgroundManyofstudiesinthesefieldshavefocusedonpharmacologicalorinvasiveinterventions,suchastopicallidocaine,IVlidocaine,acupuncture,orIVmagnesiumtopreventlaryngospasm,whereaslittleattentionhasbeenplacedontheimportanceofextubationtechnique.第23頁/共31頁NoTouchtechniqueBloodandsecretionsarecarefullysuctionedfromthepharynxThepatientisthenturnedtothelateral(recovery)positionwithadequatelyanesthetizedDiscontinuedgaswhilepositiveventilationwascontinuedwith100%oxygenuntilspontaneousventilationreturned.Nofurtherstimulationisalloweduntilpatientsspontaneouslywakeup.Trachealextubationwasperformedwhenpatientswereabletoopentheireyes.第24頁/共31頁Patientdata第25頁/共31頁ResultsLaryngospasmdidnotoccurinanyofour20studypatients.Oxygensaturationlevelsneverdecreasedtolessthan92%andnopatientsexperiencedseverecoughing