Anesthesia and the Cardiac Patient麻醉和心脏病患者

PharmacologicConsiderationsintheCardiacPatientWayneE.Ellis,Ph.D.,CRNA5/29/2024TreatmentofIschemia(primary)ASA325mgimmediatelyThrombolytics(Retevase)>flowratethanTPA2doses@30minintervalslyseclotsthroughtheactivationofplasminogen5/29/2024PrimaryTreatmentAntiplateletagents(abciximab,eptifibatide,tirofiban,integullin)GPIIb-IIIaantagonistsinhibitplateletfunctionbyblockingtheGPIIb-IIIareceptor,thefinalpathwayofplateletaggregationtherebydecreasingthrombidevelopmentandpreventsarterialvesselocclusion5/29/2024PercutaneousCoronaryInterventionAdvantagesinclude:higherrecanulazationratesimprovedbloodflowthroughtheinfarct-relatedvesselimprovedLVfunctionlowerin-hospitalmortalityratesAnestheticTechniqueGoalsofAnesthesialossofconsciousnessamnesiaanalgesiasuppressionofreflexes(endocrineandautonomic)musclerelaxationPreoperativePreparationAnginaMedicationstocontrolitBloodpressurecontrolledDiastolic<95torrCongestiveheartfailuretreatedDiureticsAfterloadreductionBedrestifindicatedControldiabetesPreoperativeMedicationsSedationPreventtachycardiaHypertensionPreparedforhypoxiaSupplementaloxygenCalciumchannelblockersnotprotectiveofperioperativeischemiaAntihypertensivescontinueondayofsurgeryStopDiuretics5/29/2024LowMolecularWeightHeparinEnoxaparin,DalteparinAnticoagulantactivitybybindingtoantithrombinIII,whichfurtherbindsandinactivatesthecoagulationfactorsIIa(thrombin)andXaAdvantagesincludedosedperbodywt.Givenq12subq.Lesstrombocytopeniaandbleeding5/29/2024OpioidsAdvantagerelatestotherelativelackofmyocardialdepressionExceptionSufenta,Carfentanil,andhighdosefentanylTheymaintainstablehemodynamicsandreduceheartrateAprimaryopioidtechniquemaybeofvalueinthepatientwithseveremyocardialdysfunctionOpioidsAdvantagesExcellentanalgesiaHemodynamicstabilityBluntreflexesCanuse100%oxygenOpioidsDisadvantagesMaynotblockhemodynamicandhormonalresponsesinpatientswithgoodLVfunctionDonotensureamnesiaChestwallrigidityRespiratorydepression5/29/2024Vasoconstrictorsareusefulinthepreventionandtreatmentofischemiar/ttheabilitytoincreasesystemicBPPhenylephrineimprovescoronaryperfusionpressure,attheexpenseofincreasingafterloadandMv025/29/2024VasoconstrictorsAtthesametime,phenylephrinecausesvenoconstriction,increasingvenousreturnandleftventricularpreload.TheincreaseinCPPmorethanoffsetstheincreaseinwalltensionInhalationAgentsAdvantagesMyocardialoxygenbalancealteredfavorablybyreductionsincontractilityandafterloadEasilytitratableCanbeadministeredviaCPBmachineRapidlyeliminated5/29/2024InhalationalAgentsDisadvantagesincludemyocardialdepressionsystemichypotensionwithpossibletachycardialackofpostoperativeanalgesiaInhalationAgentsDisadvantagesSignificanthemodynamicvariabilityMaycausetachycardiaoraltersinusnodefunctionPossibilityof“coronarystealsyndrome”InhalationAgentsPotentialforcoronarystealAlterscoronaryautoregulationAltersregionalbloodflowLittleinfluenceonoutcomeCoronaryStealArteriolardilationofnormalvesselsdivertsbloodawayfromstenoticareasCommonlyassociatedwithadenosine,dipyridamole,andSNPForanecausesstealandnewST-TsegmentdepressionMaynotbeimportantsinceForanereducesSVR,depressesthemyocardiumyetmaintainsCO5/29/2024WEEllis20AntianginalmedicationsBeta-blockersCalciumChannelBlockersNitratesNitropastemorningofsurgery5/29/2024NitratesNitroglycerin=venodialator,reducesvenousreturn,decreaseswalltension(Mv02)alsoacoronaryarterialdialator.DrugofchoiceforcoronaryvasospasmAlthoughprimarilyisasystemicvenodialator,athighdosescausesarterialdilatationandsystemichypotensionCardioactivedrugsNitroglycerinLowerLVEDPVasodilatorPoorventricularfunction5/29/2024BetaBlockersBetablockersreducemyocardialworkload(Mv02),andoxygenconsumption(V02)byreducingHR,BP,andcontractility,andtheyincreasethethresholdforventricularfibrillation.Indicationsforbetablockersinclude:sinustachycardia,supraventriculardysrhythmiasandhyperdynamicstatesBetaBlockersNegativeinotropiceffectsWithdrawalfollowingstoppageofbetablockerUnstableanginaMyocardialinfarction5/29/2024BetaBlockersPropranolol(non-selective)t1/2=4-6hoursMetoprolol(B1selective)t1/2=4-6hoursLabatelol(1:7ratio)t1/2=2-4hoursEsmolol(Beta1selective)t1/2=9.5minutesEsmololControlheartrateandbloodpressureInductionEmergenceLabetalolMixedalphaandbetaControlhypertensionHeartratemanagement5/29/2024CaChannelBlockersEvidenceforbeneficialeffectspostmiislesscompellingNifedipinetreatmentisassociatedwithatrendtowardsincreasedmortalityandreinfarctionVerapamildoesnotreducemortalityorreinfarctionVerapamil-usefulforslowingtheventricularresponseinatrialfibrillation/flutter5/29/2024CaChannelBlockersCardizem-inpt’swithnon-Qwaveinfarctionseemstoreducethereinfarctionrateduringthe1st6monthsaftertheinfarction,butincidenceoflateinfarctionwassimilartoaplacebo.Cardizemincreasescardiaceventsinpt’swithLVEF<40%,butdecreasestheirincidenceinpt’swithpreservedLVfunction5/29/2024CaChannelBlockersAllCablockersdepresscontractility,reducecoronaryandsystemictone,decreasesino-atrialnodefiring,andimpedeatrioventricularconduction.ThenegativeinatropiceffectisgreatestwithverapamilNifedipine+CardizemareusedinthepreventionofcoronaryvasospasmNifedipineControllinghypertensionManagecoronaryarteryspasm5/29/2024ACEInhibitorsAreeffectiveinreducingischemiceffectsafterMITreatmentshouldbeinstitutedwithinthe1st24hoursofallpt’swithacutemicomplicatedbysymptomaticorasymptomaticleftventriculardysfunction5/29/2024ACEInhibitorsContraindicatedinpt’swithhypotension,bilateralrenalarterystenosis,historyofacoughorangio-edemawithaceinhibitors5/29/2024AspirinASAbenefitwellestablishedasasecondarypreventionAntiplatelettherapeuticdose(75-325mg/day)otherantiplateletagentssuchasdipyridamolearenotsupportedintheliteratureexceptinpt’swithallergiestoASAwhoarepoorcandidatestooralanticoagulants5/29/2024AnticoagulantsStudiesofanticoagulanttreatmentaftermishowreductionindeath,recurrentMI,andthromboemboliticcomplicationsHowever,trialscomparingwarafintoASAforsecondarypreventionshownodifferenceinrecurrentinfarctionordeath5/29/2024AnticoagulantsAreindicatedforpt’swithASAintoleranceandforthoseatriskofembolisationfromleftventricularoratrialclot(i.e.persistentatrialfib)5/29/2024LipidLoweringAgentsmetaanalysisofclinicaltrialsshowthatlipidloweringagentsproduceareductioninfatalandnon-fatalMI’sandcardiovasculardeathsShouldbegiventopt’swithLDLconcentration>3.37mmol/1ClonidineLesshypertensionDecreasedanesthesiarequirementsAnestheticManagementRegionalvs.generalAnestheticmanagementskillsmoreimportantthantechniqueSafesttechniqueistheonethepractitionerdoesbestRegionalAnesthesiaMonitorpatientmoreaccuratelyControlsympatheticresponsesFluidsEsmololGeneralanesthesiaAvoidssympathectomyRiskswithintubationSympatheticstimulationHypoxiaIncreasedcatecholaminesLossofsubjectivemonitorChestpainIschemiaGeneralAnesthesiarequiredNarcoticsEffectivecontrolofcatecholaminesRespiratorydepressionProlongedventilationLidocaineBlunteffectsofintubation1.5mg/kg4-6minutespriortointubationNitrousOxideRarelyuseddueto:increasedPVRdepressionofmyocardialcontractilitymildincreaseinSVRairexpansionInductionDrugsBarbituratesBenzodiazepinesKetamineEtomidateAvoidKetamineHypertensionTachycardiaUseintraumaEtomidatePainfultoinjectMoreCVstabilityBarbiturateDirectdepressantExtendeddurationofactivitySmallerdoses1-2mg/kgAddbenzodiazepinesandnarcoticBenzodiazepinesQuellanxietyHemodynamicstabilityExtendeddurationofactionPotentialforhypoxiaLidocaineEsmololMuscleRelaxantsUsedto:facilitateintubationpreventshiveringattenuateskeletalmusclecontractionduringdefibrillationMuscleRelaxantsAvoidpancuroniumTachycardiaSTsegmentchangesconsistentwithischemiaDoxacuriumDurationsimilartopancuroniumNocardiovasculareffectsAvoidHistaminereleasingdrugsCurareAtracuriumMivacurium<15mcg/kgHypotensionTachycardiaNitrousOxideConstrictscoronaryarteriesAggravatesm