《肌松药的临床应用》PPT课件

第八章肌松药的临床应用,目的与要求,掌握：肌松药的应用原则以及残留肌松作用的判断熟悉：肌松药的不良反应，影响肌松药作用的因素肌松药的麻醉期间的应用了解：神经肌肉传递功能监测,Key,HypnosisAnalgesiaAmnesiaRelaxation,History,In1942GriffithandJohnsonsuggestedthatd-tubocurarine(dTc)Succinylcholine,introducedbyThesleffandFoldesetalin1952In1967BairdandReidfirstreportedpancuroniumintheearly1980softwonewmusclerelaxantsofintermediatedurationatracuriumandvecuroniumTheearly1990switnessedpipecuronium,doxacurium,mivacuriumandrocuroniumAnatracuriumisomer,cisatracuriumintroducedin1996,ClinicalUse,TrachealintubationOperationICUCureofspasticity,MolecularFeatures,NeuromuscularblockingdrugsarequaternaryammoniumcompoundsNearlyallmusclerelaxantscontaintwopositivecharges,Musclerelaxantsaregenerallyquitewater-solubleThewatersolubilityofrelaxantsinhibitsuptakeintohepatocytesMetabolismand/orexcretionintheliverisusuallynotamajorpathwayofeliminationThemusclerelaxantsareeasilyexcretedbyglomerularfiltrationintheurine,Class,DepolarizingdrugsuccinylcholineImbretil（己氨胆碱、氨酰胆碱）,PHARMACOLOGYOFSUCCINYLCHOLINE,Rapidhydrolysisbypseudocholinesterase假胆碱酯酶FactorsloweringpseudocholinesteraseconcentrationliverdiseasePregnancyBurnsoralcontraceptivesmonoamineoxidaseinhibitorscytotoxicdrugsneoplasticdiseaseanticholinesterasedrugs胆碱酯酶抑制剂,CardiovascularEffects,stimulatesnicotinicreceptorsonbothsympatheticandparasympatheticgangliaandmuscarinicreceptorsinthesinusnodeoftheheartInlowdoses,bothnegativeinotropicandchronotropic（负性变力、变频）responsesmayoccur.ThesecanbeattenuatedbyprioradministrationofatropineWithlargedoses,positiveresponses.cardiacarrhythmias,SinusBradycardiawithhighsympathetictone,suchaschildreninadultsandappearsmorecommonlyafteraseconddoseofthedrugisgivenapproximately5minutesafterthefirstpreventedbythiopental,atropine,ganglion-blockingdrugs,andnondepolarizingmusclerelaxants,Nodal(Junctional)RhythmssuppressingthesinusmechanismandallowingtheemergenceoftheatrioventricularnodeasthepacemakerpreventedbyprioradministrationofdTc,VentricularArrhythmiaslowersthethresholdoftheventricletocatecholamine-inducedarrhythmiasCirculatingcatecholamineconcentrationsincrease4-foldandpotassiumincreasesbyone-thirdOtherstimuli,suchasendotrachealintubation,hypoxia,hypercarbia,andsurgery,areprobablyadditivetotheeffectofsuccinylcholine,Complications,HyperkalemiaBurnsTraumaClosedHeadInjuryIntra-AbdominalInfectionsRenalFailureMetabolicAcidosis,IncreasedIntraocularPressureIncreasedIntragastricPressurePregnancyAscitesBowelobstructionHiatusherniaIntracranialPressureMusclePains,NondepolarizingdrugSteroidalCompoundsPancuronium,Pipecuronium,Vecuronium,RocuroniumandRapacuronium无组胺释放作用，主要经肾排泄，可松弛迷走神经松弛迷走神经中度Pancuronium,Rapacuronium轻度Rocuronium无Pipecuronium,Vecuronium,亲脂/亲水的水平决定肝脏摄取亲脂性强Vecuronium，RocuroniumandRapacuronium中短效、效能低、作用快、肝脏摄取代谢比例大，Vecuronium3040%经肝去乙酰基代谢亲脂性弱Pancuronium长效、效能高、作用慢、肝脏摄取代谢比例小，1520%经肝代谢,Benzylisoquinolinium（苄基异喹啉）Compoundsd-Tubocurarine，Metocurine，Doxacurium，Atracurium，CisatracuriumandMivacurium有组胺释放作用，可经肾排泄，不松弛迷走神经组胺释放作用显著d-Tubocurarine中度Metocurine甲筒箭毒轻度Atracurium，Mivacurium无Doxacurium，Cisatracurium给予组胺受体(H1和H2受体)阻滞药,ClassificationbyDurationofAction,Long-ActingRelaxantsRelaxantsofIntermediateDurationShort-ActingRelaxants,Long-ActingRelaxants,d-Tubocurarine，Metocurine，Doxacurium，Pancuronium，Pipecuronium，Gallamine36min起作用1.52倍ED95剂量插管80120min肌颤搐恢复25%需谨慎拮抗绝大部分经肾以原型排泄,RelaxantsofIntermediateDuration,Vecuronium，Rocuronium，Atracurium，Cisatracurium22.5min起效维持3060min4590min95%肌颤搐恢复Vecuronium,Rocuronium经肝、肾双通道排泄Atracurium,CisatracuriumHofmann效应,Short-ActingRelaxants,Mivacurium2min起效维持1220min2535min95%肌颤搐恢复血浆假性胆碱酯酶催化水解,Rapacuronium1min起效维持1520min2550min95%肌颤搐恢复经胆汁、肾排泄代谢产物仍有活性可有蓄积作用,PharmacokineticsandPharmacodynamics,DosageforTrachealIntubation,dosageintherangeoftwotothreetimestheED95isusuallygivenwithin1to3minutesIfthetracheahasalreadybeenintubatedwithoutarelaxantorwithsuccinylcholineandthepurposeissimplytoproducesurgicalrelaxation,adoseslightlylessthantheED95,MaintenanceDosage,Supplemental(maintenance)dosesofnondepolarizersrangefrom20to30percentoftheinitialdoseinthecaseoflong-actingdrugsto35to50percentoftheinitialdoseinthecaseofintermediate-andshort-actingrelaxants,ControlofDepthofNeuromuscularBlockade,tomaintain90to95percentblockofthetwitch(onetwitchvisibleonTOFstimulation)Infusiondosageisusuallydecreasedbyabout30to50percentinthepresenceofpotentinhaledanestheticsRelaxationisgenerallyinadequateformostsituationsifallfourresponsesareclearlyvisibleorpalpableduringTOFmonitoring,Ifoneortworesponsesarevisibleorpalpable,relaxationshouldbesufficientforabdominalsurgeryunderadequatedepthofanesthesiaIfonlyonetwitchisfaintlyvisibleorpalpable,relaxationshouldbedeepenoughtopermitintubationofthetracheaunderalready-establishedgeneralanesthesia,DosageforPriming,asmallsubparalyzingdoseofthenondepolarizer(about20%oftheED95orabout10%oftheintubatingdose)begiven2to4minutesbeforegivingasecondlargedosefortrachealintubation.Thisprocedure,termedpriming,hasbeenshowntoacceleratetheonsetofblockofmostnondepolarizingrelaxantsbyabout30to60secondswiththeresultthatintubationcanbeperformedwithinapproximately90secondsfollowingtheseconddoseRocuroniumandRapacuronium起效快不需预给量5倍ED95剂量以上的初始量后不需预给量,Pancuronium,stimulationofthesympatheticnervoussystemusuallycauseanincreaseinheartrate,bloodpressure,andcardiacoutputPancuroniumisclearedlargelybythekidneyAsmallamount(1020%)isdeacetylatedatthe3-positionintheliver,Pipecuronium,pipecuroniumdoesnotblockautonomicganglia,nordoesitreleasehistamineThemajorexcretorypathwayisthekidneyOnlyaverysmallamountofthedrug(5%)maybedeacetylatedatthe3-position,Vecuronium,morefaciletrachealintubationwithnondepolarizerseasieradministrationbyinfusionformaintenanceofblockadeduringsurgeryfasterandmorecompleteantagonismofresidualblockadeattheendofthecaselackofcardiovascularresponsesthroughoutawideclinicaldoserangefromonetoeighttimestheED95theliveristheprincipalorganofeliminationforvecuronium,Rocuronium,fasteronsetItisseventoeighttimeslesspotentthanvecuroniumrocuroniumproducespainoninjectionRocuroniumiseliminatedprimarilybytheliver,withasmallfraction(10%)eliminatedintheurine,Rapacuronium,lowpotency(ED901.15mg/kg)，afastonset，andshort-to-intermediatedurationlittlecardiovasculareffectThedoseof3mg/kgwasassociatedwithanincreaseofplasmahistamineRenalexcretionamountsto22percentofanadministereddoseitispossiblethatitsprincipalrouteofeliminationmaybeviatheliver,Atracurium,Hofmanneliminationdosesofmorethan0.5mg/kg(morethantwotimesED95)causethereleaseofhistamineathighdosage,Cisatracurium,CisatracuriumisaboutfourtimesmorepotentthanatracuriumandhasminimalcardiovascularsideeffectsintermediatedurationofactionHofmannelimination,Mivacurium,hydrolyzedbyplasmacholinesteraseTheshortdurationofactionenablesmaintenanceofrelaxationbycontinuousinfusionrapidinjectionofdosesof0.2to0.25mg/kgcausehistaminerelease,非去极化肌松药的复合应用,前后复合应用长时效肌松药后加用中时效或短时效肌松药，前者使后者的作用时效延长短时效肌松药后加用长时效或中时效肌松药，前者将使后者的作用时效缩短,同时复合应用化学结构为同一类的两肌松药复合应用其作用相加不是同一类的两肌松药复合应用其作用协同,影响肌松药的药代动力学因素,增加肌松药与蛋白的结合量，可增加其在体内分布容积，延缓其由肾排泄增加细胞外液量可增加肌松药在体内分布容积肝疾病引起体液潴留可增加肌松药分布容积，肝脏功能下降可引起经肝脏代谢消除延缓，作用时效延长。肾功能衰竭病人不宜应用经肾排泄的肌松药,影响肌松药的药效动力学因素,水、电解质和酸碱平衡呼吸性酸中毒增加氯筒箭毒碱和泮库溴铵的肌松作用，且使其作用不易为新斯的明拮抗代谢性酸中毒抑制新斯的明拮抗上述两肌松药低钾血症和高钠血症可增强非去极化肌松药的作用低钙血症和高镁血症减少乙酰胆碱释放，增强非去极化肌松药作用,低温低温可以减少肌肉的血流量，也可降低血浆蛋白结合肌肉松弛药的能力，使药物不易从神经肌肉接头部位转运至肝肾等器官代谢和排泄低温也影响肝脏和肾的血流量，降低代谢酶的活性低温还可影响乙酰胆碱的合成、释放，并能影响神经肌肉接头部位的敏感性,年龄新生儿体液量相对较大，分布容积增加，消除半衰延长，因此追加次数应减少老年人体液量减少和肾排泄减慢，肌松药用量应减少神经肌肉疾病重症肌无力病人用药应十分谨慎肌无力综合征病人对去极化肌松药和非去极化肌松药都十分敏感肌强直综合征病人易发生术后呼吸抑制,假性胆碱酯酶异常肝疾病、饥饿、妊娠末期及产褥期，此酶量减少或活性降低有机磷、六甲溴铵、新斯的明、单胺氧化酶抑制剂和某些抗癌药均可抑制该酶活性非典型性假性胆碱酯酶是由于遗传上的缺陷引起酶性质异常,药物相互作用,吸入全麻药吸入麻醉药增强非去极化肌松药作用的顺序是，最强为异氟烷、恩氟烷和地氟烷，其次是氟烷，最弱为氧化亚氮吸入麻醉药增强长时效非去极化肌松药如氯筒箭毒碱、泮库溴铵和哌库溴铵的作用比较明显，1/2-1/3,吸入麻醉药对中时效非去极化肌松药如维库溴铵和阿曲库铵的增强作用较弱，仅减少其药量的1/4吸入全麻药对去极化肌松药的影响相对较弱，其中以异氟烷的作用最强恩氟烷和异氟烷可促使琥珀胆碱较早演变为II相阻滞,局麻药大剂量局麻药本身就可阻滞神经肌肉接头较小剂量的局麻药能增强非去极化肌松药和去极化肌松药作用,机制局麻药作用于接头前膜，减少乙酞胆碱囊胞的含量直接作用于接头后膜阻断钠通道，从而降低接头后膜对乙酞胆碱的敏感性可直接作用于肌纤维膜的离子通道，降低肌肉的收缩能力抑制血浆假性胆碱酯酶的活性，使琥珀胆碱和米库氯铵的分解减慢，时效延长,抗心律失常药奎尼丁具有局部麻醉作用，可与非去极化肌松药和去极化肌松药产生协同作用，增强肌松药的强度和作用时效-受体阻滞药、钙通道阻滞药有可能影响神经肌肉接头的离子传导而增强肌松药作用,抗生素多粘菌素的神经肌肉接头阻滞作用是所有抗生素中最强者，其效应逆转困难，钙离子和新斯的明对其拮抗的效应均很差氨基甙类抗生素中以新霉素和链霉素抑制神经肌肉传递的功能最强，还有妥布霉素、庆大霉素，丁胺卡那霉素，均可增强非去极化肌松药和去极化肌松药作用,机制有接头前和接头后双重效应。作用于接头前膜有类似镁离子作用，影响乙酞胆碱的释放。作用于接头后有膜稳定作用。该类药物的神经肌肉接头阻滞作用可被钙离子和抗胆碱酯酶药部分拮抗林可霉素和氯霉素增强非去极化肌松药的效应，而对去极化肌松药的效应影响很小。其作用机制同样涉及接头前和接头后双重作用，并可部分被钙和新斯的明拮抗,抗惊厥药及精神药苯妥英钠与泮库溴铵、氯二甲箭毒和维库溴铵合用时，可影响后者的肌肉松弛效应，但对氯筒箭毒碱及阿曲库按无影响锂离子可取代体内的钾离子和钠离子，产生低钾血症和增强非去极化阻滞。对用锂治疗的躁狂抑郁症病人，泮库溴铵和琥珀胆碱的效应增强,肌松药的拮抗,机制使乙酰胆碱在神经肌肉接头部位的浓度相对提高，使更多的胆碱受体从与肌松药结合状态中解离出来而使神经肌肉接头恢复正常增加乙酰胆碱浓度或延长乙酰胆碱作用时间，均能拮抗非去极化肌松药的作用,抗胆碱酯酶药新斯的明、吡啶斯的明和依酚氯铵使较多的乙酰胆碱在神经肌肉接头部位积聚，与非去极化肌松药竞争受体。新斯的明还可作用于接头前膜增加乙酰胆碱释放量，且可直接兴奋胆碱受体钾通道阻滞剂4-氨基吡啶延长突触前神经的去极化作用，增加神经内Ca2+，从而增加乙酰胆碱释放量和延长乙酰胆碱释放时间为消除抗胆碱酯酶药所引起的毒蕈碱样不良反应，常需伍用抗胆碱药，如阿托品或格隆溴铵,时机肌松药应用达其维持效果后有微弱呼吸动作TOFratiotomorethan0.7单次肌颤搐刺激恢复25%以上,剂量neostigmine0.02mg/kg-0.04mg/kg阿托品0.01mg/kg-0.02mg/kg格隆溴铵7g/kg与新斯的明0.0350.07mg/kg合用可减少心率变化所引起的危险，这适用于心肌缺血和心脏瓣膜疾病病人,影响抗胆碱酯酶药的作用酸碱和电解质失衡呼吸性酸中毒不仅加强非去极化肌松药的阻滞作用，且影响抗胆碱酯酶药的作用。当动脉血二氧化碳分压（PaCO2）超过50mmHg时，抗胆碱酯酶药几乎不可能拮抗残余肌松代谢性碱中毒、低钾血症和高镁血症时，残余肌松也同样难以为抗胆碱酯酶药所逆转,低温肌松药难以从神经肌肉接头部移出抗胆碱酯酶药也难以进人神经肌肉接头老年人应用抗胆碱酯酶药应谨慎，尤其是对应用了心血管系统药物的病人，如洋地黄、-受体阻滞药和三环类抗抑郁药的病人，抗胆碱酯酶药易引起心动过缓和心律紊乱,神经肌肉传递功能监测,监测肌松药的起效、维持和消退科学合理正确地使用