75心律失常

心律失常•Cardiacarrest–ventricularfibrillation(VF)–pulselessventriculartachycardia(VT)–pulselesselectricactivity(PEA)–ventricularasystole•Cardiacarrest–ForvictimsofwitnessedVFarrest,earlyCPRandrapiddefibrillationcansignificantlyincreasethechanceforsurvivaltohospitaldischarge.•Cardiacarrest–Inadditiontohigh-qualityCPR,theonlyrhythm-specifictherapyproventoincreasesurvivaltohospitaldischargeisdefibrillationofVF/pulselessVT.•Rhythm-BasedManagementofCardiacArrest–VF/PulselessVT•resumeCPR•chargesthedefibrillator•“clear”thepatient•givesasingleshockasquicklyaspossible•resumesCPRimmediatelyfor2minutes•rhythmcheck•Rhythm-BasedManagementofCardiacArrest–DefibrillationStrategies•biphasicdefibrillator–manufacturer'srecommendedinitialdose(120to200J)–subsequentenergyshouldbeequivalent,andhigherifavailable•monophasicdefibrillator–initialshockof360J–use360Jforallsubsequentshocks•Rhythm-BasedManagementofCardiacArrest–DrugTherapyinVF/PulselessVT•atleast1shockanda2-minuteCPRperiod•vasopressor–primarygoalofincreasingmyocardialbloodflow–intravenous(IV)/intraosseous(IO)•Rhythm-BasedManagementofCardiacArrest–DrugTherapyinVF/PulselessVT•Amiodarone–IfVF/VTisunresponsivetoCPR,defibrillation,andvasopressor•lidocaine–Ifamiodaroneisunavailable•Magnesiumsulfate–onlyfortorsadesdepointesassociatedwithalongQTinterval•Rhythm-BasedManagementofCardiacArrest–TreatingPotentiallyReversibleCausesofVF/PulselessVT•PEA/Asystole–DrugTherapyforPEA/Asystole•vasopressor–theprimarygoalofincreasingmyocardialandcerebralbloodflow•atropine–unlikelytohaveatherapeuticbenefit•PEA/Asystole–TreatingPotentiallyReversibleCausesofPEA/Asystole•PEA–advancedairway–crystalloid–bloodtransfusion–empiricalfibrinolytictherapy–needledecompression–echocardiography•PEA/Asystole–TreatingPotentiallyReversibleCausesofPEA/Asystole•Asystole•AccessforParenteralMedicationsDuringCardiacArrest–Timing•high-qualityCPRandrapiddefibrillation–primaryimportance•drugadministration–secondaryimportance•AccessforParenteralMedicationsDuringCardiacArrest–PeripheralIVDrugDelivery•bolusinjectionandfollowedwitha20-mLbolusofIVfluid•elevatingtheextremity•MedicationsforArrestRhythms–Vasopressors•Epinephrine,Vasopressin,Other–Antiarrhythmics•Amiodarone,Lidocaine,MagnesiumSulfate,•Epinephrine–α-adrenergicreceptor-stimulating(ie,vasoconstrictor)properties–β-adrenergiceffects–1mgdoseofIV/IOepinephrineevery3to5minutes–2.5mgbegivenendotracheally•Vasopressin–nonadrenergicperipheralvasoconstrictor–1doseofvasopressin40unitsIV/IO•OtherVasopressors–noalternative•Amiodarone–IVamiodarone•affectssodium,potassium,andcalciumchannelsandhasα-andβ-adrenergicblockingproperties•VForpulselessVTunresponsivetoshockdelivery,CPR,andavasopressor•initialdoseof300mgIV/IOfollowedby1doseof150mgIV/IO•Lidocaine–initialdoseis1to1.5mg/kgIV–additionaldosesof0.5to0.75mg/kgIVpushmaybeadministeredat5-to10-minuteintervalstoamaximumdoseof3mg/kg•MagnesiumSulfate–facilitateterminationoftorsadesdepointes–1to2gdilutedin10mLD5W•InterventionsNotRecommendedforRoutineUseDuringCardiacArrest–Atropine–SodiumBicarbonate–Calcium–Fibrinolysis–IVFluids–Pacing–PrecordialThump•Therapy–Atropine–Pacing–AlternativeDrugstoConsider•DopamineEpinephrineIsoproterenolNarrow–QRS-complex(SVT)tachycardias(QRS0.12second)•inorderoffrequency–Sinustachycardia–Atrialfibrillation–Atrialflutter–AVnodalreentry–Accessorypathway–mediatedtachycardia–Atrialtachycardia–Multifocalatrialtachycardia(MAT)Wide–QRS-complextachycardias(QRS≥0.12second)•inorderoffrequency–Ventriculartachycardia(VT)andventricularfibrillation(VF)–SVTwithaberrancy–Pre-excitedtachycardias(Wolff-Parkinson-White[WPW]syndrome)–Ventricularpacedrhythms