RevBrasAnestesiol.2016;66(2):212---214
REVISTA
BRASILEIRA
DE
ANESTESIOLOGIA
OfficialPublicationoftheBrazilianSocietyofAnesthesiologywww.sba.com.br
CLINICAL
INFORMATION
Sedation
with
dexmedetomidine
for
conducting
electroencephalogram
in
a
patient
with
Angelman
syndrome:
a
case
report
Magda
Lourenc
¸o
Fernandes
∗,
Maria
do
Carmo
Santos,
Renato
Santiago
Gomez
SantaCasadeBeloHorizonte,BeloHorizonte,MG,Brazil
Received24February2013;accepted10June2013 Availableonline31March2014
KEYWORDS
Angelmansyndrome; EEG;
Deepsedation; Dexmedetomidine
Abstract
Introduction:Angelmansyndromeischaracterizedby severementalretardationandspeech andseizuredisorders.ThisraregeneticconditionisassociatedwithchangesinGABAAreceptor.
PatientswithAngelmansyndromeneedtobesedatedduringanelectroencephalogramordered fordiagnosticpurposesorevolutionarycontrol.Dexmedetomidine,whoseactionis indepen-dentofGABAreceptor,promotesasleepsimilartophysiologicalsleepandcanfacilitatethe performingofthisexaminationinpatientswithAngelmansyndrome.
Casereport: Femalepatient,14 yearsold,withAngelmansyndrome;electroencephalogram doneundersedationwithdexmedetomidine.Theprocedurewasuneventfulandbradycardia orrespiratorydepressionwasnotrecorded.Theexaminationwassuccessfullyinterpretedand epileptiformactivitywasnotobserved.
Conclusion:Dexmedetomidinepromotedsatisfactorysedation,waswelltoleratedandenabled the interpretation of the electroencephalogramin a patient with Angelman syndromeand seizuredisorder.
©2014SociedadeBrasileiradeAnestesiologia.PublishedbyElsevier EditoraLtda.Allrights reserved.
PALAVRAS-CHAVE
Síndromede Angelman;
Eletroencefalograma; Sedac¸ãoprofunda; Dexmedetomidina
Sedac¸ãocomdexmedetomidinapararealizac¸ãodeeletroencefalogramaempaciente
portadoradesíndromedeAngelmann:relatodecaso
Resumo
Introduc¸ão:A síndrome de Angelman (SA) é caracterizada por retardo mental grave, dis-túrbio da fala e desordem convulsiva. Essa condic¸ão genética rara está associada a alterc¸ões do receptor GABAA. Pacientes portadores de SA necessitam ser sedados durante
a feitura de eletroencefalograma (EEG), indicado para fins diagnósticos ou controle
∗Correspondingauthor.
E-mail:fernandesmagda@yahoo.com.br(M.L.Fernandes).
0104-0014/$–seefrontmatter©2014SociedadeBrasileiradeAnestesiologia.PublishedbyElsevierEditoraLtda.Allrightsreserved.
DexmedetomidineinapatientwithAngelmansyndrome 213
evolutivo.Adexmedetomidina,cujaac¸ãoindependedoreceptorGABA,promovesono semel-hanteaofisiológicoepodeviabilizarafeituradesseexameempacientescomSA.
Relatodecaso: Paciente feminina, 14 anos, portadora de SA, fez EEG sob sedac¸ão com dexmedetomidina. O procedimento transcorreu sem intercorrências e não foi registrada bradicardiaoudepressãorespiratória.Oexamefoiinterpretadocomsucessoeatividade epilep-tiformenãofoiobservada.
Conclusão:Adexmedetomidinapromoveusedac¸ãosatisfatória,foibemtoleradaepossibilitou ainterpretac¸ãodoEEGempacientecomSAedesordemconvulsiva.
©2014SociedadeBrasileira deAnestesiologia.PublicadoporElsevierEditoraLtda.Todosos direitosreservados.
Introduction
Patients with genetic disorders, common or not, with or without congenital abnormalities, present unique chal-lenges for the professional responsible for administering sedation or anaesthesia during surgical or technical procedures.Angelmansyndrome(AS)isaclearexampleof this situation,which requires specialcare because of the increased risk of complications.1 Patients withAS exhibit
convulsivedisorder,makeregularuseofanticonvulsantsand dependonelectroencephalogram(EEG)studiesfordiagnosis orevolutionarycontrol.However,becauseofthechanging behaviour,commontomanyotherneurologicalconditions, the sedation during EEG is often necessary. This is pecu-liarbecausethesedativesandhypnoticscommonlyusedin anaesthesiainterferewithEEGbasalpatterns,2wreckingits
useduringtheexamination.Inaddition,inASpatientssome geneticcharacteristicsrelatedtoacidgamma-aminobutyric acidtypeA(GABAA)areobserved,3 andGABAA isa target
forsomesedativesandhypnotics.Theaimofthisreportis todiscusstheuseofdexmedetomidineforsedationduring EEG,focusingontheuniqueaspectsofAS.
Case
report
The case is of a female patient, 14 years old, 43kg, diagnosedwithAS, withseizures, inregularuseof pheno-barbital,reportingbronchialasthmaandkyphoscoliosisand using thoracocervical vest. Laboratory tests and preoper-ative electrocardiogram were normal.In the examination room,thepatientwasmonitoredwithECG,pulseoximetry andnon-invasivemeasurementofbloodpressure.Peripheral intravenous access was obtained to allow dexmedeto-midine infusion (bolus of 1gkg---1 and maintained with 0.05---0.2gkgh---1).Thepatientremainedrelativelystable during the procedure. There wasa moderate decreasein meanarterialpressure (MAP)duringinfusion oftheinitial dose,whenthisparameterrangedfrom59to40mmHg.The heart rate ranged from80 to85bpm and nobradycardia wasobserved.Thispatienthadanepisodeofupperairway obstruction,correctedwithanoropharyngealcannula;but theoxygensaturationremainedabove92%without supple-mentaloxygen.Thedexmedetomidinedoseswereadjusted accordingtothelevelofsedationandhaemodynamiceffects and there was no spontaneous movement during the 20-minrecordingoftheEEG.Thepatientawokespontaneously 20minaftertheendofthetestandwasreleasedfromthe
unit after 90min. The analysis of EEG wasperformed by aneurologistwhofoundstages IandII ofNREM sleepand absenceofepileptiformpotentials.
Discussion
Ofrareincidence,estimatedat1/10,000---1/40,000,4ASwas
first described by Harry Angelman in 1965.5 This clinical
syndromeincludesaneurodevelopmental disorder charac-terizedbyseverelearningdifficulties,ataxia,seizures,and dysmorphicfacialfeatures.The sociable andhappy facial expression motivated the initial designation of ‘‘puppet child’’.Mostchildrenhavedevelopmentaldelayandgrowth retardationoftheheadduringthefirstyearoflife.Speech doesnotdevelopinmostpatients.ASiscausedbyavariety ofgeneticabnormalities that includechromosomalregion 15q11-13,asegmentresponsible for encodingthe gamma subunitofGABAAreceptor.6
Somerelevantpointsareworthmentioninginrelationto theparticularitiesofsedationforEEGinpatientswithAS. Thefirst oneincludes commonanaesthetic problemssuch asthosearisingfromanatomicalchangesorhaemodynamic responses. Craniofacial abnormalities, including micro-cephaly, deep-set eyes, high arched palate and tongue protrusion,3mayposeproblemsinthemanagementof
air-wayandintrachealintubation.Inthispatient,upperairway obstructionassociatedwithmacroglossiawascorrectedwith anoropharyngealairway,butrespiratorydepressionwasnot foundand noteven ventilationunder mask wasrequired. Regardless, all supportfor difficult airways approach was available, because asthma, kyphoscoliosis and the use of a thoracocervical vest represent aggravating factors for complications, ifa more invasive approach tothe airway wasneeded. Bradycardia related to vagal predominance, emphasized in other previous reports,7 was not reported
duringtheinfusionofdexmedetomidine.Incontrast, moder-atehypotensionwasobserved,butwithoutneedofspecific intervention.
The second point referstochangesin GABAA receptor,
given its importanceas a target of action of drugs com-monlyusedforsedationandanaesthesia,3suchaspropofol.
214 M.L.Fernandesetal.
beagoodstrategyforsedationand/orgeneralanaesthesia.7
Therefore,dexmedetomidine,whosetargetofactionisthe
˛2 receptor,wouldrepresent anoption, notonly asa
sin-gleagent,butalsoasanadjuncttogeneralanaesthesiaor sedation.
The last relevant aspect is the interpretation of EEG, consideringthepossibleinterferencesinitsbasalpattern, resulting from the administration of various anaesthet-icsandsedatives,includingpropofol,benzodiazepinesand inhaledanaesthetics.Even chloralhydrate,whichis tradi-tionallyusedforthispurpose,2caninterferewiththeEEG
pattern,8besidesshowingsedationfailurein27%ofpatients
with behaviour change.9 In the present report, although
theelectroencephalographicchangescommonlyseeninAS4
have notbeen observed, the analysisof this examination wassuccessfullydoneandfavouredtheclinicalcontrol.
Forallthereasonscited,dexmedetomidineemergesas apromisingresourceforpatientswithAS,especiallythose candidateswhoundergoEEGundersedation.Beingahighly selective˛2adrenergicagonist,thisdrughasamechanism
ofaction independentof GABAreceptor, promoting seda-tionvery similarto the physiological sleep,with minimal respiratorydepression.Italsohasantipruritic,antiemetic, analgesicand sympatholyticproperties.Dexmedetomidine operatesinseverallocationsinthecentralnervoussystem, but itssedative and anxiolyticeffects result mainly from itsactivity inthelocuscoeruleus ofthebrainstem.Inthe dorsalhornofthespinalcord,itmodulates thereleaseof substancePandproducesitsanalgesiceffects.Thesedation isaccompaniedbyminimaleffectsonrespiratoryfunction.10
Inadult volunteers, no interference at EEGbasal pattern wasobserved,andthesleepinducedbydexmedetomidine comparedwiththenaturalsleep.11 Consideringthatthese
resultsalsoapplytopatients withepilepsyandbehaviour changes,thisdrugtendstosetitselfupasagoodchoicefor sedationduringEEG.Someretrospectivestudiespointtothe efficacyandsafetyofthisdrugforsedationforfurther exam-inations,includingEEG,12,13althoughnoprospectivestudies
havebeenpublishedevaluatingthepossibleinterferenceof dexmedetomidineonEEGinspecialpatients.
Therefore, despite all limitations, this report high-lightsthegoodtoleranceandadequatesedationpromoted by dexmedetomidine, which enabled the recording and interpretation of EEG in our patient. Despite the little evidence,this drug mayrepresent an option for sedation
during this diagnostic procedure in patients with chronic neurological disordersandbehaviour modification, includ-ingthosepatientswithAS.However,prospectivecontrolled trialsthatspecificallyemphasizetheeffectsofthedrugon EEGareneededtoconfirmthesebenefits.
Conflicts
of
interest
Theauthorsdeclarenoconflictsofinterest.
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