外科學(xué)教學(xué)課件：Anesthesiology Overview

AnesthesiologyOverview1.Whatisanesthesia?AnesthesiaUsingDrugsorothermethodsCentralNerveSystemorperipheralnervesystemLosingsense,painlessandcomfortable,temporarilyAnesthesiaistheuseofmedicationsandclosemonitoringtoprovidecomfortandmaintainvitallifefunctionsduringsurgeryorothermedicalproceduresBeforeAnesthesiaAnalgesia-blockingtheconsciousperceptionofpainAmnesia-preventingmemoryformationRelaxation-preventingunwantedmovementormuscletoneObtundationofreflexes,preventingexaggeratedautonomicreflexesAfterAnesthesiaSurgery

andPatientbecomesafe!TheHistoryofAnesthesiologyAnestheticpracticesdatefromancienttimesTheHistoryofAnesthesiologyModernanesthesiologybeganin1846Etherwasusedasananestheticagentinhumans.WilliamT.G.Morton(1819-1868)TheHistoryofAnesthesiologyModerninhalationanestheticsweredevelopedfrom1950sto1960sIntravenousanesthesiafirstbeganin1872Useofchoralhydrate.Fromthen,manyotherintravenousagentsweredeveloped.MusclerelaxantsresultedinevolutionofanesthesiologyCurare(箭毒)wasfirstlyusedin1942TheHistoryofAnesthesiologyTheoriginalofmodernlocalanesthesiawascreditedtouseofcocainein1884.Subarachnoidanesthesia1898.Caudalepiduralanesthesia1901.lumbarepiduralanesthesia1921AnesthesiologyClinicalanesthesiaPainmanagementFirst-aidandresuscitationIntensivecareTheworkingfieldofAnesthesiologistsClinicanesthesiaOperatingroom,PACU,outpatient,CPCR(cardiopulmonarycerebralresuscitation)CCM(criticalcaremedicine)AnalgesiaPainclinic,postoperativeanalgesia,othersOthersResearch,education,trainingMajorsideeffectsandcomplicationsofanesthesiaareuncommon,especiallyinpeoplewhoareotherwisegenerallyhealthy.However,allanesthesiainvolvessomerisk.Yourspecificrisksdependonthetypeofanesthesiaused,yourhealth,andyourresponsetothemedicationsused.Isanesthesiasafeenough？OverallAnestheticRiskDeathrate:0.4–1/10,0001/200,000AnesthesiologyClassificationGeneralanesthesia:A.InhalationanesthesiaB.Intravenousanesthesia(intramuscular)Regionalanesthesia:

spinal(subarachnoid)blockepiduralblock caudalblocknerve(brachial)plexusblocklocalinfiltrationMonitoredAnestheticCareAnesthesiamethodsgenerallocalinhalationintravenousmucosamusclespinalepiduralNerveblockLocalinfiltrationtopicalbalanceDeliberatehypotensionDeliberatehypothermiaAcutenormovolemichemodilutionSpecialtechniqueAnesthesiaprocedures1.Preoperativeevaluationandpremedication2.Anesthesiainduction3.Anesthesiamaintenance4.Anesthesiatermination5.RecoveryperiodPreparingForAnesthesiaPreoperativevisitPreoperativeevaluation:History,physicalexamination,laboratoryevaluationPreoperativefastingCoexistingdiseasetherapyEquipmentpreparationPreoperativemedicationPurposesofthepreoperativevisitEstablishrapportwiththepatientObtainahistoryandperformaphysicalexaminationsOrderaspecialinvestigationsAssesstherisksofanesthesiaandsurgeryInstitutepreoperativemanagement2.preoperativeevaluationPatientevaluatedinPreOpClinic

HistoryReviewoforgansystemclinicalexaminationLaboratoryEvaluationThepurposesandproceduresofthepreoperativevisit(evaluation)Establishrapportwiththepatient.Obtainahistoryandperformaphysicalexamination.Assesstherisksofanesthesiaandsurgery.Toreduceperioperativemorbidityandmortality.

Institutepreoperativemanagement.Orderinvestigationsandprescribepremedication.Obtaininginformedconsent.History.

Presentsurgicalillness,presumptivediagnosis,initialtreatment,andresponses.Coexistingmedicalillnesses.

Medications.Allergiesanddrugreactions.

Anestheticandsurgicalhistory.Socialhistoryandhabits.Smoking,drugsandalcohol.

Thephysicalexamination

Vitalsigns:Heightandweight,bloodpressure,restingpulse,respirations.Headandneck.

Heart&lungs.

Abdomen.

Backandextremities.

Neurologicexamination.

Specialinvestigations

UrinalysisHemoglobin,plateletandcoagulation.

SerumelectrolytesandureaChestX-rayand/orechocardiographyElectrocardiographyRespiratoryfunctiontestBloodgasanalysisReviewofsystems.

Arecenthistoryofanupperrespiratoryinfection.Asthma

andCOPD.Cardiovascularsystem.Hepaticandrenalstatus.Endocrinestatus.Neurologicstatus.

ASAClassification(physicalstatusindex)

Normal,healthyⅠMildsystemicdiseaseⅡSeveresystemicdiseasethatlimitsactivitybutisnotincapacitatingⅢIncapacitatingsystemicdiseasethatisconstantthreattolifeⅣMoribund;notexpectedtosurvive24hourswithorwithoutoperationⅤEmergencyoperationE2023/3/1026ASAstatusandmortalityTalkwiththepatientandfamilyAnestheticplanandAlternatives.Planforpostoperativepaincontrol.SpecialIVorothermanipulation.Risksassociatedwithanesthesia-relatedprocedures.Bloodtransfusion.InformedConsent3.Pre-anesthesiaPreparationChoiceofAnesthesiaFactorstochoiceaanesthetictechnique1.Patientcondition2.Surgerycategory3.Thetechnicalandtheoreticlevelofanesthetist4.Anesthetics5.AnesthesiaandmonitorequipmentDrugsusedforpremedicationsedativesandanalgesics

Anticholinergics

Antiemeticagents

Medicineforpreexistingmedicalconditions

Sedation,hypnosisandamnesia,analgesia,reducingsalivationandbronchialsecreton,blockingvagalreflexASAguidelinesforNPO（fasting）statuspreoperativelyFastingfor6hourspreoperativelyNoclearliquiddrinkingfor2hourspreoperativelyNomilkforchildren4hourspreoperativelyNomeat8hourspreoperativelyCommoncausesfordelayingsurgicalprocedures.

Acuteupperrespiratorytractinfection(commoncold).Existingmedicaldiseasewhichisnotunderoptimumcontrol.Recentingestionoffoodorliquid.4.GeneralAnesthesiaUnconsciousness(Amnesia)NopainNomovementAnesthesiainductionandendotrachealintubationMaintainingtheAirwayIndicationsforendotrachealintubation36373839404142InhaledGeneralAnestheticsNitrousoxide

HalothaneEnfluraneIsofluraneSevofluraneDesfluraneXenon(rarelyused)AnesthesiaMachineInfluenceofgeneralanesthesiaonpatient’sbodyfunctionLostofairwaycontrolDepressionofcardiacfunctionDepressionofrespiratoryfunctionHypovolemiaPostoperativeProceduresAssociativewithAnesthesiaPostoperativeRecoveryRoom--Residualactivityofanesthetic&musclerelaxation--NauseaandVomiting--PainReliefGuedel'sclassification

AnesthesiadepthStagesofAnesthesia[edit]StageI

(stageofanalgesiaordisorientation):frombeginningofinductionofgeneralanesthesiatolossofconsciousness.StageII

(stageofexcitementordelirium):fromlossofconsciousnesstoonsetofautomaticbreathing.Eyelashreflexdisappearbutotherreflexesremainintactandcoughing,vomitingandstrugglingmayoccur;respirationcanbeirregularwithbreath-holding.StageIII

(stageofsurgicalanesthesia):fromonsetofautomaticrespirationtorespiratoryparalysis.StageIV:from

stoppageofrespiration

tilldeath.Anestheticoverdosecausemedullaryparalysiswithrespiratoryarrestandvasomotorcollapse.Pupilsarewidelydilatedandmusclesarerelaxed.51AnesthesiacomplicationsInadequatepreoperativeplanninganderrorsinpatientpreparationarethemostcommomcausesofanesthesticcomplicationsAnesthesiaandelectiveoperationsshouldnotproceeduntilthepatientisinoptimalmedicalcondition52AnestheticcomplicationsHumanerror(technicalproblems,lackofcommunication,experience,fatigue,)Ventilation(breathingcircuit,defectofmonitoringequipment,anesthesiamachine)Position(peripheralnervedamage)AnaphylaxisLatexallergy53AnesthesiaandperioperativecomplicationsAirwayCirculationCentralandperipheralnervoussystemPaintherapyDrugsusedinanesthesiaEquipmentfailureComplicationofgeneralanesthesia1RespiratoryobstructionLaryngealspasmBronchospasmHypotensionHypertensionComplicationofgeneralanesthesia2CardiacarrhythmiaHypovolemiaHypothermiaEmbolismMalignanthyperpyrexiaComplicationsofendotrachealintubationFailuretointubatethetracheal.InjurytothelocaltissueOthercomplicationsasgeneralanesthesiaWhathappensduringrecoveryfromanesthesia?PACU/RecoveryRoomDrowsinessandRespiratoryDepressionNumbness&ResidualmusclerelaxantHypothermia&ShiveringNausea&VomitingPain&AgitationUnstablevitalsignsandHypotension5.AnestheticPharmacologyPharmacologyofInhalationanesthetics（Volatile）

PropertiesofinhalationanestheticsMAC(minimumalveolarconcentration)Theequilibriumend-tidalanestheticconcentrationthatpreventmovementinresponsetosurgicalskinincisionin50%ofhumansubjects.Enflurane

Goodhypnosis,analgesiaandskeletalmusclerelaxation.Lowblood/gaspartitioncoefficient.Dose-relateddepressionofmyocardialcontractility.Fosterelectroencephalographic(EEG)change.Convulsionsandevengrandmalseizurescouldoccurinsomecases(withPaCO2decreasing).Isoflurane

Anesthesiaeffectissimilarinmostrespectstothoseofenflurane.Itproduceslittlemyocardialcontractilitydepressionbutdoescauseperipheralvasculardepression.Thebloodpressuremaygoesdownandtachycardiacouldoccur.ItdoesnotproduceseizuresorEEGchangesseenwithenflurane.SevofluraneLowblood/gaspartitioncoefficient0.6GoodfortheinhilationinductiononthechildrenDesfluraneLowblood/gaspartitioncoefficient0.43SpecialvaporizerneededIntravenousanesthesiaContext-sensitivehalf–timeThetimerequiredforthebloodconcentrationofadrugtodecreaseto50%ofthesteady-statevalueafteraninfusionisdiscontinued.contexsensitivehalf-timeThiopental

1Ultrashort-actingbarbiturateandhighlylipidsolubleNervoussystem:intravenousinjectionofthiopentalproducesprofoundandrapidhypnosis,littleanalgesiaeffect.Cardiovascularsystem:Itcausesdepressionofmyocardialcontractilityandperipheralvasodilation.Thiopental

2Respiratorysystem:DepressingrespiratorycentreDoseandadministration:3-5mg/kgof2.5%solutionintravenouslyPropofolAlmostsameeffectsasthatofthiopetalFavourablerecoverycharacteristicsDosage:1.5-2.5mg/kgivforinduction.1-10mg/kg/minTarget-ControlledInfusionKetamine

1Causeatypeofthalamicdisconnectiontermed“dissociativeanesthesia”.GoodanalgesiawithconsciousnessSideeffects:purposelessmovement,frighteningdreams,vividvisualhallucinations,screamingandcrying.Ketamine

2Lesscardiovasculardepression.Sensethereleaseofcatecholamine:increaseofBP,HR,bloodflowtoorganandICP.Transientapnea.Poormusclerelaxation.Doseandadministration:1-3mg/kgintravenously.5mg/kgintramuscularlyOpioidsMorphine

Diamorphine,(diacetylmorphine,alsoknownasheroin)Codeine,(methylmorphine)Fentanyl(Sublimaze,Durogesic)Alfentanil

Sufentanil

Remifentanil

Meperidine,alsocalledpethidine(Demerol)Methadone

Oxycodone(Oxycontin)Naloxone,chemicallysimilartosomeanalgesics;notapainkillerandreversestheeffectsofmorphine-likeagents.Nalbuphine(Nubain)Butorphanol(Stadol)SideeffectsofOpioidsAnalgesiaRespiratorydepressionIleus/delayedgastricmotilityNausea&vomitingHypotensionPruritusNEUROMUSCULARBLOCKERSNeuromuscularblockersexerttheireffectbyinterferinginsomewaywiththenormalactionofacetylcholine.Theyareusedmostcommonlytofacilitateendotrachealintubationandtoreducemuscletonetoprovideabdominalmusclerelaxation.Depolarizingneuromuscularblockers

ProductionoffasciculationAbsenceofposttetanicfacilitationPotentiationbyanticholinesteraseagentsNondepolarizingneuromuscularblockersNofasciculationareproducedPosttetanicfacilitationispresentAnticholinesteraseagentsantagonizetheblockApplicationoftheneuromuscularblockersAlltheagentscanbeusedinanesthesiainductionandmaintenance.But,succinylcholineisbetterforanesthesiainductionbecauseitproducesrapidonsetandabriefdurationofaction.Othernondepolarizingagentsarebetterformaintenanceofanesthesiawithslowonsetandlongerduration.AttentiontotheneuromuscularblockersAssistantorcontrolledventilationshouldbeemployedafterinjectionofneuromuscularblockers.Themuscletonefortherespirationhasbeenlost.Reversaloftheblockade

Theactionofnondepolarizingneuromuscularblockingagentsmaybeantagonizedbyneostigmine,whichincreasethelocalconcentrationofacetylcholineattheendplate.6.Regionalanesthesia

(Localanesthesia)

Localanesthetics

Esters:Procaine(Novocaine)Tetracaine(Pontocaine)Amides:Lidocaine(Xylocaine)Bupivacaine(Marcaine)Ropivacaineprocaine

amethocaine

cocaine

lidocaine(Xylocaine)prilocaine

bupivicaine(Sensorcaine)levobupivacaine(Levobupivacaine)ropivacaine

dibucaine

MaximumRecommendedDose:A.Lidocaine2%1.Withoutepinephrine(5mg/kg)2.Withepinephrine7mg/kgB.Bupivacaine5%1.Withandwithoutepinephrine3mg/kgMechanismoftheactionLocalanestheticsinterferewiththedepolarizationphaseoftheactionpotentialbyreducingthepermeabilityofthemembranetosodiumions.ManipulationofepiduralanesthesiaSpinal:alsoknownassubarachnoidblock.Referstoaregionalblockresultingfromasmallvolumeoflocalanestheticsbeinginjectedintothespinalcanal.Thespinalcanaliscoveredbytheduramater,throughwhichthespinalneedleenters.Thespinalcanalcontainscerebrospinalfluidandthespinalcord.Thesubarachnoidblockisusuallyinjectedbetweenthe4thand5thlumbar

vertebrae,becausethespinalcordusuallystopsatthe1stlumbarvertebra,whilethecanalcontinuestothesacralvertebrae.Itresultsinalossofpainsensationandmusclestrength,usuallyuptothelevelofthechest(nipplelineor4ththoracicdermatome).Differentialnerveblock

SympatheticfibresblockadeSensoryblockadeMotorblockadeRespiratorysystem

Lowspinalblockshavenoeffectonrespiratorysystem.Thoraciclevelblockscauselossofintercostalmuscleactivity.Blocksextendingashighastherootofphrenicnerve(3,4,5)causetotalapnea.CardiovascularsystemSympatheticblockproducesdilatationofresistanceandcapacitancevesselsresultinginhypotension(tachycardia).Bradycardiamayoccurbecauseofblockofcardiacsympatheticfibres(T1toT5).Gastro--intestinalsystem

Nausea,retchingorvomitingmayoccurintheawakepatientandareproducedby1.unopposedparasympatheticactivity.2.hypotension.ContraindicationstospinalanesthesiaandextraduralblockAnticoagulanttherapySepsisonskinofbackHypovolemiaActivebacterialorvirusinfectionsoftheperipheralandcentralnervoussystem.Elevationofintracranialpressure.Brachialplexusblock

AxiallyapproachSupraclavicularbrachialblockInterscalenebrachialblockUltrasonicguidednervalblockPreciselyandsafethanever

sideeffectofLA:AbsorptionofthelocalanestheticintothebloodCentralnervoussystemeffects1Inhibitionorblockadeofinhibitorypathwayincerebralcortex.Dizzinessorlightheadache,anxious,drowsiness,disorientation,temporaryunconsciousness,slurredspeech,shivering,muscletwitchingandconvulsion.Centralnervoussystemeffects2DepressionofbothinhibitoryandfacilibilitypathwaysresultsinthegeneralizedstateofCNSdepression--coma.Cardiovasculareffectsprolongationofphase4depolarizationinPurkinjeiFibersprolongationofconductiontimethroughvariousportionofheartdirectnegativeinotropicaction--myocardialcontractilitycardiacoutputcirculatorycollapse,cardiacarrestHRBP

Respiratoryeffects

Atnontoxicdoses,adirectrelaxanteffectonbronchialsmoothmuscleoccurs.ExcessiveamountsoflocalanestheticagentscancauserespiratoryarrestfromgeneralizedCNSdepression,apnea.FactorsaffectingtoxicityAninadvertentintravascularinjectionAbsoluteoverdoseAbsorptionMetabolismPreventionoftoxicity

Avoidintravascularinjectionandoverdosage.Usingthesolutioncontainingadrenaline(1:200,000)hasbeenadvocated.Thevasoconstrictorcanreducetheabsorption.Treatmentoftoxicity

1Ensuringapatientairwayandprovidingsupplementaloxygenwithfacemask.Usingartificialventilationifapneaoccurs.Treatmentoftoxicity

2Ifthecardiovascularcollapseoccurs,itshouldbetreatedwithvasopressor,positiveinotropicagents,inordertosupportthecirculation.Anadrenergicdrugwithaand?properties,e.g.ephedrinein5mgincrements.Treatmentoftoxicity

3Convulsionmaybecontrolledwithsmallincrementsofeitherdiazepam(2.5mg)orthiopentone(50mg)intravenously.AllergicreactionAllergytotheestersarerelativelycommon,particularlywithprocaine.Allergytotheamidesisextremelyrare.Complicationofextraduralanesthesia1(serious)Duraltapleadingto:a.Totalspinalanesthesiab.PostspinalanesthesiaheadacheToxicityoflocalanalgesicagentsHypotensionRespiratoryInsufficiency

Complicationofextraduralanesthesia2(serious)InadvertentinjectionofchemicalirritantsHemotomaformationEpiduralabscessTraumatospinalcordandnerverootsComplicationofepiduralanesthesia3(lessSerious)NauseaandvomitingShiveringHorner’ssyndromeAnesthesiaMonitors

monitoringofheartrate(ECG),oxygensaturation(pulseoximetry)bloodpressure(NIBP&IBP–arterial)inspiredandexpiredgases(foroxygen,nitrousoxide,carbondioxide,andvolatileagents)monitoringoftemperaturecentralvenouspressurecerebralactivity(EEG)neuromuscularactivity (peripheralnervestimulationmonitoring)urineoutputbloodsugarlevelsbuildupofexhaledinhalationalanesthetics

CardiopulmonaryResuscitation

(CPR)2010Concept復(fù)蘇resuscitation心肺復(fù)蘇card-pulmonaryresuscitation心肺腦復(fù)蘇card-pulmonary-cerebralresuscitationtrauma

disease

中毒

drown、electricshockcardiopulmonaryarrest

reasonJudgeofcardiopulmonaryarrest1、suddenlossconsciousness2、Noheartsounds，arterypulse,bloodpressure3、Stopbreathingorsighbreath4、mydriasis5、cyanosisorgreyinskinandmucosa心肺復(fù)蘇存活率

4分鐘以內(nèi)50％

4～6分鐘開始10％

6分鐘以后4％

10分鐘以上≈0

時間就是生命

cardiopulmonaryresuscitationin4to6minutestoestablishbasiclifesupportguaranteeoxygensupplyofbasicorganadvancedlifesupportCPRphase基本生命支持高級生命支持持續(xù)生命支持