颅脑损伤(英文版)

“Boy,doIhaveanExcedrinheadache!!”managingtheheadinjuredpatientLeaugeayWebreBS,CCEMT-P,NREMT-PScenario•WhiledescendingMtHoodinOregon,Bobtumbledheadoverheels,andcametoastopdanglingoffaprecipicebyhisTelemarkskiat11,000ft.OnarrivaltheskipatrolparamedicsBob’sbreathingwassonorousandshallow,andhehadaGCSof3-4.Theonlyobviousinjuriesweretohishead.HisBPwas87/55,HR100andRR16•Howshouldtheparamedicstreatthispatient?•Shouldhebeintubated?•Shouldhebefluidresuscitated?•Commonmajortrauma•4millionpeopleexperienceheadtraumaannually–Severeheadinjuryismostfrequentcauseoftraumadeath•GSWtocranium:75-80%mortality•AtRiskpopulation–Males15-24–Infants–YoungChildren–ElderlyIntroductiontoHead,Facial,&NeckInjuries•TIMEISCRITICAL–IntracranialHemorrhage–ProgressingEdema•IncreasedICP•CerebralHypoxia•PermanentDamage•Severityisdifficulttorecognize–Subtlesigns–Improvedifferentialdiagnosis•ImprovessurvivabilityIntroductiontoHead,Facial,&NeckInjuries•Scalp–StrongFlexiblemassof•Skin•Fascia•MuscularTissue–HighlyVascular–HairprovidesInsulation–StructuresBeneath•GaleaAponeurotica–Betweenscalpandskull–Fibrousconnectivesheath•Subaponeurotica(Areolar)Tissue–Permitsvenousbloodflowfromtheduralsinusestothevenousvesselsofscalp•EmissaryVeins:PotentialrouteforInfectionAnatomy&PhysiologyoftheHeadParietalSutureLineFrontalTemporalOrbitsMaxillaeMandibleTemporalMandibularJointOcciptalNasalBonesZygomaticArchSphenoidForamenMagnum(HoleinBase)•Brain–Occupies80%ofcranium–Comprisedof3MajorStructures•Cerebrum•Cerebellum•Brainstem–Highmetabolicrate•Receives15%ofcardiacoutput•Consumes20%ofbody’soxygen•Requiresconstantcirculation–IFBloodsupplystops•Unconsciouswithin10seconds•Deathin4-6minutesAnatomy&PhysiologyoftheHead•CerebralPerfusionPressure–Pressurewithincranium(ICP)resistsbloodflowandgoodperfusiontotheCNS•Pressureusuallylessthan10mmHg–MeanArterialPressure(MAP)•Mustbeatleast50mmHgtoensureadequateperfusion•MAP=DBP+1/3PulsePressure–CerebralPerfusionPressure(CPP)•Pressuremovingbloodthroughthecranium•CPP=MAP-ICPAnatomy&PhysiologyoftheHead•CalculatingMAP(meanarterialpressure)–DBP+1/3PP–PP(pulsepressure)=SBP-DBP–SBP+2(DBP)3•CalculatingCPP(cerebralperfusionpressure)–MAP–ICP–ICPnormally10Anatomy&PhysiologyoftheHead8010-90CPPICP-MAPCPP10ICP&90MAP•CerebralPerfusionPressure–Autoregulation•ChangesinICPresultincompensation•IncreasedICP=IncreasedBP–ThiscausesICPtorisehigherandBPtorise•Braininjuryanddeathbecomeimminent–Expandingmassinsidecranialvault•DisplacesCSF•Ifpressureincreases,braintissueisdisplacedAnatomy&PhysiologyoftheHeadFaceMusclesMChewingmusclesMPosteriorpalateandpharynxMFaceMusclesMSightSOpticIIPupilConst,Rectus&ObliquesMOculomotorIIIOpthalmic(FH),Maxillary(cheek)Mandible(chin)STrigeminalVLateralrectusmuscleMAbducensVITastetoposteriortongueSVagusXTongueMHypoglossalXIITrapezius&Sternocleido.MusclesMAccessoryXIHearingbalanceSAcousticVIIISuperiorObliquesMTrochlearIVTongueSFacialVIIPosteriorpharynx,tastetoanteriortongueSGlossopharyn-gealIXSmellSOlfactoryIInnervationFNameCNTypesofTrauma•Softtissue•Skullfracture•Primarybraininjuries•Secondarybraininjuries•Thepatientpresentedtotheemergencydepartmentwiththegolfcubinhishead,whichwasremovedintheoperatingroomLateralskullx-rayofapatientwhopresentedwithasevereintracranialinjuryproducedbyagolfclubScalpInjury•Contusions•Lacerations•Avulsions•SignificantHemorrhageALWAYSReconsiderMOIforsevereunderlyingproblemsBrainInjury•AsdefinedbytheNationalHeadInjuryFoundation–“atraumaticinsulttothebraincapableofproducingphysical,intellectual,emotional,socialandvocationalchanges.”–Classification•Direct–Primaryinjurycausedbyforcesoftrauma•Indirect–SecondaryinjurycausedbyfactorsresultingfromtheprimaryinjuryDirectBrainInjuryTypes•Coup–Injuryatsiteofimpact•Contrecoup–InjuryonoppositesidefromimpactIntracranialPerfusion•Review–Cranialvolumefixed•80%=Cerebrum,cerebellum&brainstem•12%=Bloodvessels&blood•8%=CSF–Increaseinsizeofonecomponentdiminishessizeofanother•Inabilitytoadjust=increasedICPIntracranialPerfusion•CompensatingforPressure–Compressvenousbloodvessels–ReductioninfreeCSF•Pushedintospinalcord•DecompensatingforPressure–IncreaseinICP–RiseinsystemicBPtoperfusebrain•FurtherincreaseofICP–DangerouscycleICPBPIntracranialPressure•RoleofCarbonDioxide–IncreaseofCO2inCSF•CerebralVasodilation–Encouragebloodflow–Reducehypercarbia–Reducehypoxia–ContributestoICP–Causesclassic•Hyperventilation&Hypertension–ReducedlevelsofCO2inCSF•Cerebralvasoconstriction–ResultsincerebralanoxiaFactorsAffectingICP•VasculatureConstriction•CerebralEdema•SystolicBloodPressure–LowBP=PoorCerebralPerfusion–HighBP=IncreasedICP•CarbonDioxide•Reducedrespiratoryefficiency•Increasedpressure–Compressesbraintissue•Against&around–FalxCerebri–TentoriumCerebelli–Herniatesbrainstem•Compromisesbloodsupply•Signs&Symptoms–UpperBrainstem•Vomiting•Alteredmentalstatus•Pupillarydilation–MedullaOblongata•Respiratory•Cardiovascular•BloodPressuredisturbancesPressure&StructuralDisplacement•AlteredMentalStatus–Alteredorientation–Alterationinpersonality–Amnesia•Retrograde•Antegrade•Cushing’sReflex–Increased