Delirium: Practice Essentials, Background, Pathophysiology

Delirium is defined as a transient, usually reversible, cause of mental dysfunction and manifests clinically with a wide range of ... ForYou News&Perspective Drugs&Diseases CME&Education Academy Video DecisionPoint Edition: ENGLISH DEUTSCH ESPAÑOL FRANÇAIS PORTUGUÊS LogIn SignUpIt'sFree! Edition: ENGLISH DEUTSCH ESPAÑOL FRANÇAIS PORTUGUÊS Register LogIn NoResults NoResults ForYou News&Perspective Drugs&Diseases CME&Education Academy Video DecisionPoint close PleaseconfirmthatyouwouldliketologoutofMedscape. Ifyoulogout,youwillberequiredtoenteryourusernameandpasswordthenexttimeyouvisit. Logout Cancel https://profreg.medscape.com/px/getpracticeprofile.do?method=getProfessionalProfile&urlCache=aHR0cHM6Ly9lbWVkaWNpbmUubWVkc2NhcGUuY29tL2FydGljbGUvMjg4ODkwLW92ZXJ2aWV3 processing.... Drugs&Diseases > Psychiatry Delirium Updated:Apr25,2019 Author:KannayiramAlagiakrishnan,MD,MBBS,MPH,MHA;ChiefEditor:GlenLXiong,MD more... Share Email Print Feedback Close Facebook Twitter LinkedIn WhatsApp Sections Delirium Sections Delirium Overview PracticeEssentials Background Pathophysiology Mortality/Morbidity Epidemiology ShowAll Presentation History Physical Causes ShowAll DDx Workup LaboratoryStudies ImagingStudies OtherTests ShowAll Treatment MedicalCare Consultations ShowAll Guidelines Medication MedicationSummary Antipsychotics Benzodiazepines Vitamins Hypnotic,Miscellaneous ShowAll Follow-up FurtherOutpatientCare FurtherInpatientCare Deterrence/Prevention Complications Prognosis PatientEducation ShowAll Questions&Answers Tables References Overview PracticeEssentials Deliriumisdefinedasatransient,usuallyreversible,causeofmentaldysfunctionandmanifestsclinicallywithawiderangeofneuropsychiatricabnormalities.Itcanoccuratanyage,butitoccursmorecommonlyinpatientswhoareelderlyandhaveapreviouslycompromisedmentalstatus. Signsandsymptoms Theclinicalhallmarksofdeliriumaredecreasedattentionorawarenessandachangeinbaselinecognition.Deliriumoftenmanifestsasawaxingandwaningtypeofconfusion.Symptomsincludethefollowing: Cloudingofconsciousness Difficultymaintainingorshiftingattention Disorientation Illusions Hallucinations Fluctuatinglevelsofconsciousness Dysphasia Dysarthria Tremor Asterixisinhepaticencephalopathyanduremia Motorabnormalities SeeClinicalPresentationformoredetail. Diagnosis Thediagnosisofdeliriumisclinical.Nolaboratorytestcandiagnosedelirium. Diagnosticcriteria TheDiagnosticandStatisticalManualofMentalDisorders,FifthEdition(DSM-5)diagnosticcriteriafordeliriumisasfollows [1]: Disturbanceinattention(ie,reducedabilitytodirect,focus,sustain,andshiftattention)andawareness. Changeincognition(eg,memorydeficit,disorientation,languagedisturbance,perceptualdisturbance)thatisnotbetteraccountedforbyapreexisting,established,orevolvingdementia. Thedisturbancedevelopsoverashortperiod(usuallyhourstodays)andtendstofluctuateduringthecourseoftheday. Thereisevidencefromthehistory,physicalexamination,orlaboratoryfindingsthatthedisturbanceiscausedbyadirectphysiologicconsequenceofageneralmedicalcondition,anintoxicatingsubstance,medicationuse,ormorethanonecause. Assessmentinstruments Someofthemeasuresusedtoidentifydeliriumincludethefollowing: ConfusionAssessmentMethod(CAM) DeliriumSymptomInterview(DSI) ConfusionAssessmentMethodfortheIntensiveCareUnit(CAM-ICU) IntensiveCareDeliriumScreeningChecklist(ICDSC) DeliriumsymptomseveritycanbeassessedbytheDeliriumDetectionScale(DDS)andtheMemorialDeliriumAssessmentScale(MDAS). SeeWorkupformoredetail. Management Thegoaloftreatmentistodeterminethecauseofthedeliriumandstoporreverseit.Componentsofdeliriummanagementincludesupportivetherapyandpharmacologicmanagement. Fluidandnutritionshouldbegivencarefullybecausethepatientmaybeunwillingorphysicallyunabletomaintainabalancedintake.Forthepatientsuspectedofhavingalcoholtoxicityoralcoholwithdrawal,managementshouldincludemultivitamins,especiallythiamine. Reorientationtechniquesormemorycuessuchasacalendar,clocks,andfamilyphotosmaybehelpful.Theenvironmentshouldbestable,quiet,andwell-lighted. Deliriumthatcausesinjurytothepatientorothersshouldbetreatedwithmedications.Themostcommonmedicationsusedareantipsychoticmedications.Benzodiazepinesoftenareusedforwithdrawalstates. SeeTreatmentandMedicationformoredetail. Next: Background Deliriumisatransientglobaldisorderofcognition.Theconditionisamedicalemergencyassociatedwithincreasedmorbidityandmortalityrates.Earlydiagnosisandresolutionofsymptomsarecorrelatedwiththemostfavorableoutcomes.  Deliriumisnotadiseasebutasyndromewithmultiplecausesthatresultinasimilarconstellationofsignsandsymptoms.Deliriumisdefinedasatransient,usuallyreversible,causeofmentaldysfunctionandmanifestsclinicallywithawiderangeofneuropsychiatricabnormalities.Theclinicalhallmarksaredecreasedawarenessandattentionspanandawaxingandwaningtypeofconfusion. Deliriumisoftenunrecognizedormisdiagnosedasdementia,depression,mania,psychoticdisorders,oratypicalresponseoftheagingbraintohospitalization.  Previous Next: Pathophysiology Basedonthelevelofpsychomotoractivity,deliriumcanbedescribedashyperactive,hypoactive,ormixed.Hyperactivedeliriumisobservedinpatientsinastateofalcoholwithdrawalorintoxicationwithphencyclidine(PCP),amphetamine,andlysergicaciddiethylamide(LSD).Thesepatientsoftenexhibitagitation,restlessness,hallucinations,ordelusions. Hypoactivedeliriumisobservedinpatientsinstatesofhepaticencephalopathyandhypercapniaandmaybemorecommoninolderadults. Hypoactivedeliriumpresentswithlethargy,drowsiness,apathy,decreasedresponsiveness,orslowedmotorskills. Inmixeddelirium,individualsdisplayeitherrelativelynormallevelsofpsychomotoractivityorrapidlyfluctuatinglevelsofactivity. [1,2] Themechanismofdeliriumstillisnotfullyunderstood.Deliriumresultsfromawidevarietyofstructuralorphysiologicalinsults.Theneuropathogenesisofdeliriumhasbeenstudiedinpatientswithhepaticencephalopathyandalcoholwithdrawal.Researchintheseareasstillislimited.Themainhypothesisisreversibleimpairmentofcerebraloxidativemetabolismandmultipleneurotransmitterabnormalities.Thefollowingobservationssupportthehypothesisofmultipleneurotransmitterabnormalities. [3] Acetylcholine Datafromanimalandclinicalstudiessupportthehypothesisthatacetylcholineisoneofthecriticalneurotransmittersinthepathogenesisofdelirium. [4]Asmallprospectivestudyamongpatientswhohaveundergoneelectivehipreplacementsurgeryshowedreducedpreoperativeplasmacholinesteraseactivityinasmanyasonequarterofpatients.Inaddition,reducedpreoperativecholinesteraselevelsweresignificantlycorrelatedwithpostoperativedelirium. [5] Clinically,goodreasonssupportthishypothesis.Anticholinergicmedicationsareawell-knowncauseofacuteconfusionalstates,andpatientswithimpairedcholinergictransmission,suchthosewithAlzheimerdisease,areparticularlysusceptible.Inpatientswithpostoperativedelirium,serumanticholinergicactivitymaybeincreased. [6] Dopamine Inthebrain,areciprocalrelationshipexistsbetweencholinergicanddopaminergicactivities.Indelirium,anexcessofdopaminergicactivityoccurs.Symptomaticreliefoccurswithantipsychoticmedicationssuchashaloperidolandotherneurolepticdopamineblockers. Otherneurotransmitters Serotonin:Humanandanimalstudieshavefoundthatserotoninisincreasedinpatientswithhepaticencephalopathyandsepticdelirium.HallucinogenssuchasLSDactasagonistsatthesiteofserotoninreceptors.Serotonergicagentsalsocancausedelirium. Gamma-aminobutyricacid(GABA):Inpatientswithhepaticencephalopathy,increasedinhibitoryGABAlevelsalsoareobserved.Anincreaseinammonialevelsoccursinpatientswithhepaticencephalopathy,whichcausesanincreaseintheaminoacidsglutamateandglutamine,whichareprecursorstoGABA.DecreasesinCNSGABAlevelsareobservedinpatientswithdeliriumresultingfrombenzodiazepineandalcoholwithdrawal. Cortisolandbeta-endorphins:Deliriumhasbeenassociatedwiththedisruptionofcortisolandbeta-endorphincircadianrhythms.Thismechanismhasbeensuggestedasapossibleexplanationfordeliriumcausedbyexogenousglucocorticoids. Disturbedmelatonindisturbancehasbeenassociatedwithsleepdisturbancesindelirium. [7] Inflammatorymechanism Recentstudieshavesuggestedaroleforcytokines,suchasinterleukin-1andinterleukin-6,inthepathogenesisofdelirium.Followingawiderangeofinfectious,inflammatory,andtoxicinsults,endogenouspyrogen,suchasinterleukin-1,isreleasedfromthecells.Headtraumaandischemia,whichfrequentlyareassociatedwithdelirium,arecharacterizedbybrainresponsesthataremediatedbyinterleukin-1andinterleukin-6. [8,9] Stressreactionmechanism Studiesindicatepsychosocialstressandsleepdeprivationfacilitatetheonsetofdelirium. Structuralmechanism Thespecificneuronalpathwaysthatcausedeliriumareunknown.Imagingstudiesofmetabolic(eg,hepaticencephalopathy)andstructural(eg,traumaticbraininjury,stroke)factorssupportthehypothesisthatcertainanatomicalpathwaysmayplayamoreimportantrolethanothers.Thereticularformationanditsconnectionsarethemainsitesofarousalandattention.Thedorsaltegmentalpathwayprojectingfromthemesencephalicreticularformationtothetectumandthethalamusisinvolvedindelirium. Disruptedblood-brainbarriercanallowneurotoxicagentsandinflammatorycytokinestoenterthebrainandmaycausedelirium.Contrast-enhancedMRIcanbeusedtoassesstheblood-brainbarrier. [10,11] Visuoperceptualdeficitsindeliriumsuchashallucinationsanddelusionsarenotduetotheunderlyingcognitiveimpairment. [12]Visualhallucinationsduringalcohol-withdrawaldeliriumareseeninsubjectswithpolymorphismsofgenescodingfordopaminetransporterandcatechol-O-methyltransferase(COMT). [13] Previous Next: Mortality/Morbidity Inpatientswhoareadmittedwithdelirium,mortalityratesare10-26%. [14] Patientswhodevelopdeliriumduringhospitalizationhaveamortalityrateof22-76%andahighrateofdeathduringthemonthsfollowingdischarge. [15]. Inareviewof28studiesofcriticallyillpatientstherateofdeathforpatientswithdeliriumwasmorethandoubled. [16] Inpatientswhoareelderlyandpatientsinthepostoperativeperiod,deliriummayresultinaprolongedhospitalstay,increasedcomplications,increasedcost,andlong-termdisability. [17] Accordingtoonestudy, deliriumisassociatedwithworsesurvivalandgreaterresourceconsumptioninthosewithcardiaccriticalillness.Among590patientsincluded,theprevalenceofcardiac(C)ICUdeliriumwas20.3%.Deliriouspatientswereolder,hadgreaterdiseaseseverity,requiredlongerICUstays(5vs2days;P<.001 previous next: epidemiology frequency deliriumiscommonintheunitedstates.inasystematicreviewof42cohortsin40studies forpatientsin prevalenceofpostoperativedeliriumfollowinggeneralsurgeryis5 age deliriumcanoccuratanyage clinicalpresentation references americanpsychiatricassociation.diagnosticandstatisticalmanualofmentaldisorders kalabalikj maldonadojr.neuropathogenesisofdelirium:reviewofcurrentetiologictheoriesandcommonpathways.amjgeriatr psychiatry.2013dec.21 whites.theneuropathogenesisofdelirium.revclingerontol.2002.12:62-67. cerejeiraj robinsontn shigetah derooijse rudolphjl ebersoldtm bankswh.theagedblood-brainbarrier:asubstrateforcnsdisease.facts brownlj limosinf mccuskerj americanpsychiatricassociation.practiceguidelineforthetreatmentofpatientswithdelirium.amjpsychiatry. salluhji marcantonioer pauleye siddiqin folsteinmf yesavageja mcavaygj farrellkr colem ouimets inouyesk alagiakrishnank netoas brooksm.newscoringtoolgaugesseverityofdelirium.medscapemedicalnews.april15 perrysw.organicmentaldisorderscausedbyhiv:updateonearlydiagnosisandtreatment.amjpsychiatry.1990jun.1 vanmusterbc vanrompaeyb martinezf kishit neufeldkj overshottr vaneijkmm tampirr mundiglerg alagiakrishnank.melatoninbasedtherapiesfordeliriumanddementia.discovmed.may2016.21 andersoncp maclullichamj alsopdc bergeronn chand dayjj elyew hendersond.delirium:commontreatmentnobetterthanplacebo.medscapemedicalnews.availableathttp: hungol inouyesk.thedilemmaofdelirium:clinicalandresearchcontroversiesregardingdiagnosisandevaluationofdelir iuminhospitalizedelderlymedicalpatients.amjmed.1994sep.97 jonesrn lesliedl lipowskizj.delirium lipowskizj.deliriumintheelderlypatient.nengljmed.1989mar2.320 liptzinb o obrechtr otterh pagevj sipahimalania teslyarp trzepaczpt.delirium.advancesindiagnosis matthewsfe davisd mediagallery of tables table1.differentiatingfeaturesofdeliriumanddementia features delirium dementia onset acute insidious course fluctuating progressive duration daystoweeks monthstoyears consciousness altered clear attention impaired normal psychomotorchanges increasedordecreased oftennormal reversibility usually rarely backtolist contributorinformationanddisclosures author kannayiramalagiakrishnan specialtyeditorboard franciscotalavera chiefeditor glenlxiong additionalcontributors mohammedamemon acknowledgements patriciablanchette disclosure:nothingtodisclose. close whatwouldyouliketoprint printthissection printtheentirecontentsof printtheentirecontentsofarticle sections overview practiceessentials background pathophysiology mortality showall presentation history physical causes ddx workup laboratorystudies imagingstudies othertests treatment medicalcare consultations guidelines medication medicationsummary antipsychotics benzodiazepines vitamins hypnotic follow-up furtheroutpatientcare furtherinpatientcare deterrence complications prognosis patienteducation questions finduson about aboutmedscape privacypolicy editorialpolicy cookies donotsellmypersonalinformation termsofuse advertisingpolicy helpcenter membership becomeamember aboutyou professionalinformation newsletters apps medscape cme webmdnetwork medscapeliveevents webmd medicinenet emedicinehealth rxlist webmdcorporate editions english deutsch espa fran portugu allmaterialonthiswebsiteisprotectedbycopyright encodedsearchterm whattoreadnextonmedscape relatedconditionsanddiseases alzheimerdisease alzheimerdiseaseimaging alzheimerdiseaseandapoee4 alzheimerdiseaseindownsyndrome dementiapathology fastfivequiz:alzheimerdiseasemanagement fastfivequiz:alzheimer medscapeconsult news alopeciatiedtoathreefoldincreasedriskfordementia studycautionsagainstuseofmirtazapinetotreatagitationindementiapatients tools druginteractionchecker pillidentifier calculators formulary slideshow alzheimerdisease:diagnosticchallenges mostpopulararticles accordingtoneurologists anonverbal33-year-oldwomanwithintellectualimpairment asexuallyactive23-year-oldwithseizuresandtonguepain viewmore recommended diseases howearlyistooearlyforthediagnosisofalzheimerdisease youarebeingredirectedto medscapeeducation yes alzheimer needacurbsideconsult sharecasesandquestionswithphysiciansonmedscapeconsult. share acase>