资源描述
Intracranial HypertensionGeneY.Sung,M.D.,M.P.H.Director,NeurocriticalCareandStrokeDivisionUniversity of Southern CaliforniaIntracranial Pressure PhysiologyMonro-Kellie Doctrine(1783/1824)1.Rigid container2.Liquid contents are incompressible3.Mass must be displacedIntracranial Pressure PhysiologyCranial ContentsTotal Volume 1300-1500 ccBrain 80%gray matter/white matterCSF 10%Intraventricular 50%75 ccSubarachnoid 50%75 ccBlood 10%Arterial 30%45ccVenous 70%105ccIntracranial Pressure PathophysiologyBlood epidural,subdural,subarachnoid,intracerebral,intraventricular,intravascularTumorAbscess/InfectionForeign ObjectsAir pneumocephalusCranial RestrictionPagets disease,craniosynostosisHydrocephalus,Cysts,HygromaEdemaInterstitial e.g.CNS lymph system,brain as a spongeCytotoxic dead/dying cellsVasogenic altered BBB,capillary breakdown,abscessIntracranial Pressure PathophysiologyMass DisplacementCSF Blood BrainICP/CPP 150125100755025002550Cerebral Perfusion Pressure(mm Hg)Cerebral Blood Flow(ml/100 g/min)ZoneofNormalAutoregulationMaximumConstrictionMaximumDilatationPassiveCollapse02550ICP(mm Hg)Vasodilatory Cascade ZoneAutoregulation Breakthrough ZoneStephan A.Mayer,MDIntracranial Pressure PhysiologyIntracranial Pressure PathophysiologyHerniation TypesStructureBarrierVesselSubfalcine cingulate g.falxACAUncal uncustentoriumPCATonsillarcerebellum foramen m.vert/bUpwardcerebellum tentoriumTranscalvarialcortexskullsurfaceIntracranial Pressure PathophysiologyHerniation Types1.Subfalcine2.Uncal3.tonsillarIntracranial Pressure PathophysiologyElevated ICP Clinical SymptomsHeadache-Aggravated by bending and stooping.Caused bydistortionorirritationofpainsensitiveareasintheduralcoveringsandbloodvessels.Vomiting-Causedbycompressionorischemiaofbrainstem.Usuallyoccurswithlesionsoftheposteriorfossa.Thisisusuallytheresultofhydrocephalusand4thventricledilationcausingstimulationofthenucleusofvagusnerve.Personality and behavior changes-A depression in motor andthoughtprocessesthatcanleadtosomnolence,anddecreasedlevelofconsciousnessandcoma.Causedbycompressiononthereticularsubstanceofupperbrainstemandthalamuscausesthisphenomenon.Papilledema-thisisusuallytheresultofincreasedCSFpressureintheopticnervesheathimpedingvenousdrainageandaxoplasmicflowinopticneurons.PapilledemaElevated ICP Clinical SymptomsCranial NeuropathyCN III or VICushings TriadHypertension/Increased Pulse PressureBradycardiaIrregular RespirationElevated ICP Clinical SymptomsICP MeasurementRadiographicNot particularly accurateOther Non-invasiveUnproven:infra-red,laser,TCD(Pulsatility Index)InvasiveLumbar punctureOtherICP Measurement ICP TreatmentHead of Bed 30 degreesImproves venous drainageLasixDiuretic decreases intravascular volumeMannitol (older agents glycerol,urea)Osmotic diureticDiuretic decreases intravascular volumeOsmotic agent removes free water by osmosisViscosity improves micro-circulation ICP TreatmentSedation/AgitationDecrease unnecessarily elevated blood pressure and intravascular volumeIntubation/HyperventilationDecrease pCO2(25-30 torr),change H+gradient at blood vessel causing vasoconstriction,leading to decreased intravascular volumeFevercontrolHyperthermialeadstoincreasedcerebralbloodflowandincreasedbloodvolumeICP TreatmentBarbiturate ComaDecrease cerebral metabolic demandHypothermiaDecrease cerebral metabolic demandHypertonic SalineOsmotic gradientsSurgeryElevated ICP TreatmentElevated ICP TreatmentI USED TO HAVE AN OPEN MIND BUT MY BRAINS KEPT FALLING OUT George CarlinHemicraniectomy TrialsDECIMAL-FranceDESTINY-GermanyHAMLET-NetherlandsCombined AnalysisNIHSS 15MCA strokeWithin 45 hoursCombined AnalysisSevere disability or death 12 monthsARR 51.2%,p0.0001Death 12 monthsARR 50.3%,p0.0001Elevated ICP TreatmentHemicraniectomyNovel Approaches to ICH/IVH Mass EffectAspiration+/-thrombolysis.This makes intuitive sense.Does it work?
展开阅读全文