(推荐课件)小儿麻醉对认知的影响

CognitionandBrainStructureFollowingEarlyChildhoodSurgeryWithAnesthesia,1,儿童期是敏感的神经发育阶段，由于麻醉药能够强烈的兴奋或抑制神经传递，因此麻醉药能够干扰神经网络发育，导致长期功能障碍。在动物幼体实验中发现，麻醉后会出现神经元缺失和长期的学习、记忆损伤等神经认知功能受损的情况,前言,2,由于小儿特殊的生理和心理特点，麻醉是否会对其脑功能有所影响、麻醉药是否影响其发育等一直以来都是麻醉科、儿科和神经科医生普遍关注的问题。虽然进行了大量的研究，许多问题尚未清楚。,3,Background,Anestheticsinducewidespreadcelldeath,permanentneuronaldeletion,andabstractneurocognitiveimpairmentinimmatureanimals,raisingsubstantialconcernsaboutsimilareffectsoccurringinyoungchildren.,4,Background,Epidemiologicstudieshavebeenunabletosufficientlyaddressthisconcern,inpartduetorelianceongroup-administeredachievementtests,inabilitytoassessbrainstructure,andlimitedcontrolforconfounders.,5,Methods,Wecomparedhealthyparticipantsofalanguagedevelopmentstudyatage5to18yearswhohadundergonesurgerywithanesthesiabefore4yearsofage(n=53)withunexposedpeers(n=53)whowerematchedforage,gender,handedness,andsocioeconomicstatus.NeurocognitiveassessmentsincludedtheOralandWrittenLanguageScalesandtheWechslerIntelligenceScales(WAIS)orWISC,asappropriateforage.BrainstructuralcomparisonswereconductedbyusingT1-weightedMRIscans.,6,方法,7,Results,Averagetestscoreswerewithinpopulationnorms,regardlessofsurgicalhistory.However,comparedwithcontrolsubjects,previouslyexposedchildrenscoredsignificantlylowerinlisteningcomprehensionandperformanceIQ.,8,智力,9,听力理解能力,10,Results,Exposuredidnotleadtogrosseliminationofgraymatterinregionspreviouslyidentifiedasvulnerableinanimals.DecreasedperformanceIQandlanguagecomprehension,however,wereassociatedwithlowergraymatterdensityintheoccipitalcortexandcerebellum.,11,12,Conclusions,Thepresentfindingssuggestthatgeneralanesthesiaforasurgicalprocedureinearlychildhoodmaybeassociatedwithlong-termdiminutionoflanguageabilitiesandcognition,aswellasregionalvolumetricalterationsinbrainstructure.,13,Conclusions,Althoughcausationremainsunresolved,thesefindingsnonethelesswarrantadditionalresearchintothephenomenonsmechanismandmitigatingstrategies.,14,15,为什么成年人和儿童早期接受麻醉后的影响差异很大？动物研究发现，未完全成熟的小脑神经元易受麻醉药物影响，而小脑结构的损害可能与较低的IQ相关。,讨论,16,动物实验证明：全麻药物可诱发神经细胞凋亡，最终导致神经系统功能损害,17,动物研究发现，未完全成熟的小脑神经元易受麻醉药物影响，而小脑结构的损害可能与较低的IQ相关。,18,全麻药触发啮齿类动物发育期大脑的神经细胞凋亡，并致成年期的神经功能缺陷，在人类发育期大脑全麻药是否也能导致相似的神经毒性？,19,临床上没有足够临床资料和流行病学证据；麻醉后人脑神经元凋亡的组织学证据也无法获得（在实践上和道德上是不可能的）Wilder等和Kallman等回顾性研究认为4岁前接受麻醉药，使用一种以上全麻药和长时间暴露是导致学习能力减退的危险因素，其中2岁前暴露风险较大,20,21,并不能排除这些神经认知功能方面的异常是由围手术期因素导致的，例如疼痛、炎症反应或一些遗传相关的因素。未能区分手术和麻醉各自本身的影响，也不能排除需要手术的患儿原发疾病更易发生学习能力减退的可能目前并没有排除这些因素的干扰。,讨论-混杂因素,22,分析发现，对于本研究中绝大多数接受麻醉的孩子，各项量表的评分不仅在正常范围内，甚至有的还高于总体人群平均水平。因此，如果将这些孩子与总体人群比较，则显示麻醉并没有上述不良影响。,讨论-统计学,23,Ourstudyhasseverallimitations.TheMRIdatausedinthisstudyarebetween8and11yearsold.Morecontemporaryimagingtechniquesmightprovidebetterresolutionandimprovedsensitivitytosubtlebrainvolumetricdifferences.Furthermore,thetimingbetweenthesurgicalprocedureandtheMRIscanandneurocognitiveassessmentvariedfromlessthan2to15yearsaftersurgery,whichcouldhavelimitedtheextentofthedetectablechangesduetobrainplasticityandrepair.Thestudyssamplesizewasrelativelysmall,andthetimeintervalsincetheoriginalstudymadeadequatefollow-updifficult.Moreover,studyparticipantswerevolunteeredbytheirparentsfortheinitiallanguageassessmentstudy,whichcouldaffectgeneralizabilityoftheresultstoabroaderpopulationbutdidnotinfluencethecomparisonsbetweenthe2studygroups,whichweredrawnfromthesamecohort.Astypicalforsurgeryininfantsandtoddlers,manychildreninourstudyunderwentsurgeryforchronicearinfections,whichcouldpotentiallyhaveinfluencedlanguagedevelopmentduetohearingimpairment,24,Concernsforneurobehavioraldisordersandabnormalitiesinbrainfunctioncausedbyenvironmentalchemicalexposureduringearlybraindevelopmenthaverecentlybeenextendedtoanestheticsandsedatives,whichareadministeredtomillionsofyoungchildrenworldwide.1,16Manysurgicalproceduresearlyinlifetreatlife-threateningconditions,avertserioushealthcomplications,orimprovequalityoflifeandthereforecannotbeeasilypostponedoravoided.Neurotoxiceffectsofallcommonlyusedanestheticsandsedativeshavenowbeenfoundinawidevarietyofanimalspecies,andpostexposurelearningimpairmentshavebeendocumentedinrodentsandnonhumanprimates.8,17Accordingly,thepresentstudyassessedtheeffectsofearlychildhoodanesthesiaforsurgeryonlong-termcognitivefunctionandbrainstructurebycomparingpreviouslyexposedchildren,whoseanesthesiarecordswerereviewed,versusmatchedunexposedcontrolsubjectstolimitconfoundingofcognitiveperformanceandstructuralassessmen,25,对麻醉的神经毒性的临床研究,26,27,28,29,临床试验,探讨麻醉药物是否引起小儿的认知功能障碍和学习记忆力减退1、Anesthesiology杂志2009，回顾性研究文章，认为4岁以前接受多次手术麻醉，可导致学习能力下降。2、上