Increased Intracranial Pressure.ppt

IncreasedIntracranialPressure ICP Dr BelalHijji RN PhDFebruary20 22 2012 2 LearningOutcomes Bytheendofthislecture studentswillbeableto DefineICPandrecognisethecausesofincreasedICPanditsconsequencesDiscussthepathophysiologyofincreasedICPanditsclinicalmanifestationsDescribetheassessmentanddiagnosticfindingsofincreasedICPRecognisethemedicalandnursingmanagementofapatientwithincreasedICP 3 Introduction Thecraniumcontainsbraintissue 1 400g blood 75mL andCSF 75mL ThevolumeandpressureofthesethreecomponentsareusuallyinastateofequilibriumandproducetheICP whichis10to20mmHgandrepresentsthepressurewithintherigidskull CausesofincreasedICPincludeariseincerebrospinalfluidpressure increasedpressurewithinthebrainmatter bleedingintothebrainorfluidaroundthebrain orswellingwithinthebrainmatteritself Anincreaseinintracranialpressureisaseriousmedicalproblem Thepressureitselfcandamagethebrainorspinalcordbypressingonimportantbrainstructuresandbyrestrictingbloodflowintothebrain 4 Subduralhematomadevelopswhenbloodvesselsthatarelocatedbetweenthemembranescoveringthebrain themeninges leakbloodafteraninjurytothehead Thisisaseriousconditionsincetheincreaseinintracranialpressurecancausedamagetobraintissueandlossofbrainfunction 5 Pathophysiology IncreasedICPisasyndromethataffectsmanypatientswithacuteneurologicconditions AnelevatedICPismostcommonlyassociatedwithheadinjury secondaryeffectinotherconditions suchasbraintumors subarachnoidhemorrhage andtoxicandviralencephalopathies IncreasedICPfromanycausedecreasescerebralperfusion stimulatesfurtherswelling edema andshiftsbraintissuethroughopeningsintherigiddura resultinginbrainherniation nextslide afrequentlyfatalevent 6 7 ClinicalManifestations WhenICPincreasestothepointatwhichthebrain sabilitytoadjusthasreacheditslimits neuralfunctionisimpaired thismaybemanifestedbyclinicalchangesfirstinLOCandlaterbyabnormalrespiratoryandvasomotorresponses Slowingofspeechanddelayinresponsetoverbalsuggestionsareotherearlyindicators Restlessness withoutapparentcause confusion orincreasingdrowsiness hasneurologicsignificance Thesesignsmayresultfromcompressionofthebrainduetoswellingfromhemorrhageoredema anexpandingintracraniallesion hematomaortumor oracombinationofboth Continued 8 AsICPincreases thepatientbecomesstuporous reactingonlytoloudauditoryorpainfulstimuli Atthisstage seriousimpairmentofbraincirculationisprobablytakingplace andimmediateinterventionisrequired Asneurologicfunctiondeterioratesfurther thepatientbecomescomatoseandexhibitsabnormalmotorresponsesintheformofdecorticateordecerebrateposture seenextslide Whenthecomaisprofound withthepupilsdilatedandfixedandrespirationsimpaired deathisusuallyinevitable 9 10 AssessmentandDiagnosticFindings Thepatientmayundergocerebralangiography computedtomography CT scanning ormagneticresonanceimaging MRI TranscranialDopplerstudiesprovideinformationaboutcerebralbloodflow ThepatientwithincreasedICPmayalsoundergoelectrophysiologicmonitoringtomonitorthepressure nextslide LumbarpunctureisavoidedinpatientswithincreasedICPbecausethesuddenreleaseofpressurecancausethebraintoherniate 11 Intracranialpressuremonitoringisperformedbyinsertingacatheterintotheheadwithasensingdevicetomonitorthepressurearoundthebrain 12 MedicalManagement IncreasedICPisatrueemergencyandmustbetreatedimmediatelythrough InvasivemonitoringofICPtoidentifyincreasedpressureearlyinitscourse beforecerebraldamageoccurs toquantifythedegreeofelevation toinitiateappropriatetreatment toprovideaccesstoCSFforsamplinganddrainage andtoevaluatetheeffectivenessoftreatment Decreasingcerebraledema Osmoticdiuretics mannitol maybegiventodehydratethebraintissueandreducecerebraledema Theyreducethevolumeofbrainandextracellularfluid Corticosteroids eg dexamethasone helpreducecerebraledemawhenabraintumoristhecauseofincreasedICP 13 Maintainingcerebralperfusion Thecardiacoutputmaybemanipulatedtoprovideadequateperfusiontothebrain Inotropicagentssuchasdobutaminehydrochlorideareused Theeffectivenessofthecardiacoutputisreflectedinthecerebralperfusionpressure whichismaintainedatgreaterthan70mmHg Alowercerebralperfusionpressureindicatesthatthecardiacoutputisinsufficienttomaintainadequatecerebralperfusion Cerebralperfusionpressure CPP isdefinedasthedifferencebetweenmeanarterialandintracranialpressures Meanarterialpressureisthediastolicpressureplusonethirdofthepulsepressure differencebetweenthesystolicanddiastolic MAPisthusbetweensystolicanddiastolicpressures CPP MAP ICPNormalcerebralperfusionpressureis80mmHg nearerdiastolic 14 LoweringthevolumeofCSFandcerebralblood CSFdrainageisfrequentlyperformedbecausetheremovalofCSFwithaventriculostomydrainmaydramaticallyreduceICPandrestorecerebralperfusionpressure Controllingfever Preventingatemperatureelevationiscriticalbecausefeverincreasescerebralmetabolismandtherateatwhichcerebraledemaforms Maintainingoxygenation Arterialbloodgasesmustbemonitoredtoensurethatsystemicoxygenationremainsoptimal Hemoglobinsaturationcanalsobeoptimizedtoprovideoxygenmoreefficientlyatthecellularlevel 15 Reducingmetabolicdemands Cellularmetabolicdemandsmaybereducedthroughtheadministrationofhighdosesofbarbiturateswhenthepatientisunresponsivetoconventionaltreatment Anothermethodistheadministrationofpharmacologicparalyzingagents Becausethepatientwhoreceivestheseagentscannotrespondorreportpain sedationandanalgesiamustbeprovided 16 NursingProcess ThePatientWithIncreasedICP Assessment Obtainahistoryofeventsleadingtothepresentillness itmaybenecessarytoobtainthisinformationfromsignificantothers Theneurologicexaminationshouldincludeanevaluationofmentalstatus levelofconsciousness LOC cranialnervefunction cerebellarfunction balanceandcoordination reflexes andmotorandsensoryfunction AssessmentofLOCincludeseyeopening verbalandmotorresponses pupils size equality reactiontolight Becausethepatientiscriticallyill ongoingassessmentwillbemorefocused includingpupilchecks assessmentofselectedcranialnerves frequentmeasurementsofvitalsignsandintracranialpressure anduseoftheGlasgowComaScale nextslide whichisatoolforassessingapatient sLOC Scoresrangefrom3 deepcoma to15 normal 17 GlasgowComaScale EyeopeningresponseSpontaneous4Tovoice3Topain2None1BestverbalresponseOriented5Confused4Inappropriatewords3Incomprehensiblesounds2None1BestmotorresponseObeyscommand6Localizespain5Withdraws4Flexion decorticate 3Extension decerebrate 2None1Total3to15 18 Nursingdiagnoses Ineffectiveairwayclearancerelatedtodiminishedprotectivereflexes cough gag Ineffectivebreathingpatternsrelatedtoneurologicdysfunction brainstemcompression structuraldisplacement IneffectivecerebraltissueperfusionrelatedtotheeffectsofincreasedICP 19 PlanningandgoalsMaintenanceofapatentairwayNormalizationofrespirationAdequatecerebraltissueperfusionthroughreductioninICP 20 NursingInterventions Maintainingpatentairway Assessthepatencyoftheairway Suctionwithcarethesecretionsobstructingtheairway becausetransientelevationsofICPoccurwithsuctioning Thepatientishyperoxygenatedbeforeandaftersuctioningtomaintainadequateoxygenation DiscouragecoughingbecauseitincreasesICP Auscultatethelungfieldsatleastevery8hourstodeterminethepresenceofabnormalbreathsounds Elevatetheheadofthebedmayaidinclearingsecretionsaswellasimprovingvenousdrainageofthebrain Continued 21 AchievinganadequatebreathingpatternMonitorthepatientconstantlyforrespiratoryirregularities ThisincludesCheyne Stokesrespirations alternatingperiodsofhyperpneaandapnea Seepicturebelow andhyperventilation increasedrateanddepthofbreathing Nextslide ContinuedonSlide23 22 Hyperventilation 23 MonitorPaCO2 normalrange35to45mmHg ifhyperventilationtherapyhasbeendecidedtoreduceICP bycausingcerebralvasoconstrictionandadecreaseincerebralbloodvolume Maintainaneurologicobservationrecord Repeatedassessmentsofthepatientaremadefrequentlytoimmediatelynoteimprovementordeterioration Prepareforsurgicalinterventionincaseofdeterioration 24 OptimisingcerebraltissueperfusionMaintainheadalignmentandelevateheadofbed30degrees Therationaleisthathyperextension rotation orhyperflexionoftheneckcausesdecreasedvenousreturn Avoidextremehipflexionasthisincreasesintra abdominalandintrathoracicpressures leadingtoriseinICP AvoidtheValsalvamaneuver strainingatstool asitraisesICP Administerstoolsoftenersasprescribed Ifappropriate providehighfiberdiet No