ARTICLE IN PRESS+ModelBJANE-209; No. of Pages 3

Rev Bras Anestesiol. 2014;xxx(xx):xxx.e1---xxx.e3

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CLINICAL INFORMATION

Sedation with dexmedetomidine for conductingelectroencephalogram in a patient with Angelman syndrome:a case report

Magda Lourenco Fernandes ∗, Maria do Carmo Santos, Renato Santiago Gomez

Santa Casa de Belo Horizonte, Belo Horizonte, MG, Brazil

Received 24 February 2013; accepted 10 June 2013

KEYWORDSAngelman syndrome;EEG;Deep sedation;Dexmedetomidine

AbstractIntroduction: Angelman syndrome is characterized by severe mental retardation and speechand seizure disorders. This rare genetic condition is associated with changes in GABAA receptor.Patients with Angelman syndrome need to be sedated during an electroencephalogram orderedfor diagnostic purposes or evolutionary control. Dexmedetomidine, whose action is indepen-dent of GABA receptor, promotes a sleep similar to physiological sleep and can facilitate theperforming of this examination in patients with Angelman syndrome.Case report: female patient, 14 years old, with Angelman syndrome; electroencephalogramdone under sedation with dexmedetomidine. The procedure was uneventful and bradycardiaor respiratory depression was not recorded. The examination was successfully interpreted andepileptiform activity was not observed.Conclusion: dexmedetomidine promoted satisfactory sedation, was well tolerated and enabledthe interpretation of the electroencephalogram in a patient with Angelman syndrome and

seizure disorder.© 2014 Sociedade Brasileira de Anestesiologia. Published by Elsevier Editora Ltda. All rightsreserved.

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Introduction

Patients with genetic disorders, common or not, with or

Please cite this article in press as: Fernandes ML, eing electroencephalogram in a patient with Angelman shttp://dx.doi.org/10.1016/j.bjane.2013.06.020

without congenital abnormalities, present unique chal-lenges for the professional responsible for administeringsedation or anaesthesia during surgical or technical

∗ Corresponding author.E-mail: fernandesmagda@yahoo.com.br (M.L. Fernandes).

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0104-0014/$ – see front matter © 2014 Sociedade Brasileira de Anestesiohttp://dx.doi.org/10.1016/j.bjane.2013.06.020

rocedures. Angelman syndrome (AS) is a clear example ofhis situation, which requires special care because of thencreased risk of complications.1 Patients with AS exhibitonvulsive disorder, make regular use of anticonvulsants andepend on electroencephalogram (EEG) studies for diagnosisr evolutionary control. However, because of the changingehaviour, common to many other neurological conditions,

t al. Sedation with dexmedetomidine for conduct-yndrome: a case report. Rev Bras Anestesiol. 2014.

he sedation during EEG is often necessary. This is pecu-iar because the sedatives and hypnotics commonly used innaesthesia interfere with EEG basal patterns,2 wrecking itsse during the examination. In addition, in AS patients some

logia. Published by Elsevier Editora Ltda. All rights reserved.

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enetic characteristics related to acid gamma-aminobutyriccid type A (GABAA) are observed,3 and GABAA is a targetor some sedatives and hypnotics. The aim of this report iso discuss the use of dexmedetomidine for sedation duringEG, focusing on the unique aspects of AS.

ase report

he case is of a female patient, 14 years old, 43 kg,iagnosed with AS, with seizures, in regular use of pheno-arbital, reporting bronchial asthma and kyphoscoliosis andsing thoracocervical vest. Laboratory tests and preoper-tive electrocardiogram were normal. In the examinationoom, the patient was monitored with ECG, pulse oximetrynd non-invasive measurement of blood pressure. Peripheralntravenous access was obtained to allow dexmedeto-idine infusion (bolus of 1 �g kg---1 and maintained with

.05---0.2 �g kg h---1). The patient remained relatively stableuring the procedure. There was a moderate decrease inean arterial pressure (MAP) during infusion of the initialose, when this parameter ranged from 59 to 40 mmHg. Theeart rate ranged from 80 to 85 bpm and no bradycardiaas observed. This patient had an episode of upper airwaybstruction, corrected with an oropharyngeal cannula; buthe oxygen saturation remained above 92% without supple-ental oxygen. The dexmedetomidine doses were adjusted

ccording to the level of sedation and haemodynamic effectsnd there was no spontaneous movement during the 20-in recording of the EEG. The patient awoke spontaneously

0 min after the end of the test and was released from thenit after 90 min. The analysis of EEG was performed by

neurologist who found stages I and II of NREM sleep andbsence of epileptiform potentials.

iscussion

f rare incidence, estimated at 1/10,000---1/40,000,4 AS wasrst described by Harry Angelman in 1965.5 This clinicalyndrome includes a neurodevelopmental disorder charac-erized by severe learning difficulties, ataxia, seizures, andysmorphic facial features. The sociable and happy facialxpression motivated the initial designation of ‘‘puppethild’’. Most children have developmental delay and growthetardation of the head during the first year of life. Speechoes not develop in most patients. AS is caused by a varietyf genetic abnormalities that include chromosomal region5q11-13, a segment responsible for encoding the gammaubunit of GABAA receptor.6

Some relevant points are worth mentioning in relation tohe particularities of sedation for EEG in patients with AS.he first one includes common anaesthetic problems suchs those arising from anatomical changes or haemodynamicesponses. Craniofacial abnormalities, including micro-ephaly, deep-set eyes, high arched palate and tonguerotrusion,3 may pose problems in the management of air-ay and in tracheal intubation. In this patient, upper airwaybstruction associated with macroglossia was corrected with

Please cite this article in press as: Fernandes ML, eing electroencephalogram in a patient with Angelman shttp://dx.doi.org/10.1016/j.bjane.2013.06.020

n oropharyngeal airway, but respiratory depression was notound and not even ventilation under mask was required.egardless, all support for difficult airways approach wasvailable, because asthma, kyphoscoliosis and the use of

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thoracocervical vest represent aggravating factors foromplications, if a more invasive approach to the airwayas needed. Bradycardia related to vagal predominance,mphasized in other previous reports,7 was not reporteduring the infusion of dexmedetomidine. In contrast, moder-te hypotension was observed, but without need of specificntervention.

The second point refers to changes in GABAA receptor,iven its importance as a target of action of drugs com-only used for sedation and anaesthesia,3 such as propofol.espite the relevance of this aspect, clinical information onhe effects of such drugs in this special group of patients iscarce and not fully understood. It is estimated that a vari-tion in clinical response or even a resistance to such drugsccurs, which is why some authors suggest that their asso-iation with other drugs acting on different pathways woulde a good strategy for sedation and/or general anaesthesia.7

herefore, dexmedetomidine, whose target of action is the2 receptor, would represent an option, not only as a sin-le agent, but also as an adjunct to general anaesthesia oredation.

The last relevant aspect is the interpretation of EEG,onsidering the possible interferences in its basal pattern,esulting from the administration of various anaesthet-cs and sedatives, including propofol, benzodiazepines andnhaled anaesthetics. Even chloral hydrate, which is tradi-ionally used for this purpose,2 can interfere with the EEGattern,8 besides showing sedation failure in 27% of patientsith behaviour change.9 In the present report, although

he electroencephalographic changes commonly seen in AS4

ave not been observed, the analysis of this examinationas successfully done and favoured the clinical control.

For all the reasons cited, dexmedetomidine emerges as promising resource for patients with AS, especially thoseandidates who undergo EEG under sedation. Being a highlyelective ˛2 adrenergic agonist, this drug has a mechanismf action independent of GABA receptor, promoting seda-ion very similar to the physiological sleep, with minimalespiratory depression. It also has antipruritic, antiemetic,nalgesic and sympatholytic properties. Dexmedetomidineperates in several locations in the central nervous system,ut its sedative and anxiolytic effects result mainly fromts activity in the locus coeruleus of the brainstem. In theorsal horn of the spinal cord, it modulates the release ofubstance P and produces its analgesic effects. The sedations accompanied by minimal effects on respiratory function.10

n adult volunteers, no interference at EEG basal patternas observed, and the sleep induced by dexmedetomidineompared with the natural sleep.11 Considering that theseesults also apply to patients with epilepsy and behaviourhanges, this drug tends to set itself up as a good choice foredation during EEG. Some retrospective studies point to thefficacy and safety of this drug for sedation for further exam-nations, including EEG,12,13 although no prospective studiesave been published evaluating the possible interference ofexmedetomidine on EEG in special patients.

Therefore, despite all limitations, this report high-ights the good tolerance and adequate sedation promoted

t al. Sedation with dexmedetomidine for conduct-yndrome: a case report. Rev Bras Anestesiol. 2014.

y dexmedetomidine, which enabled the recording andnterpretation of EEG in our patient. Despite the littlevidence, this drug may represent an option for sedationuring this diagnostic procedure in patients with chronic

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ARTICLEBJANE-209; No. of Pages 3

Dexmedetomidine in a patient with Angelman syndrome

neurological disorders and behaviour modification, includ-ing those patients with AS. However, prospective controlledtrials that specifically emphasize the effects of the drug onEEG are needed to confirm these benefits.

Conflicts of interest

The authors declare no conflicts of interest.

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4. Laan LA, Vein AA. Angelman syndrome: is there a characteristicEEG? Brain Dev. 2005;27:80---7.

5. Angelman H. ‘‘Puppet’’ children. A report on three cases. DevMed Child Neurol. 1965;7:681---8.

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t al. Sedation with dexmedetomidine for conduct-yndrome: a case report. Rev Bras Anestesiol. 2014.

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