UC IrvineJournal of Education and Teaching in Emergency Medicine

TitleThe Halloween Lateral Canthotomy Model

Permalinkhttps://escholarship.org/uc/item/9hm782vj

JournalJournal of Education and Teaching in Emergency Medicine, 2(2)

ISSN2474-1949

AuthorsNadir, Nur-AinSattar, IfatAhmed, Ammar

Publication Date2017-01-01

LicenseCC BY 4.0 Peer reviewed

eScholarship.org Powered by the California Digital LibraryUniversity of California

INNOVATIONS

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TheHalloweenLateralCanthotomyModelNur-AinNadir,MD,MHPE*,IfatSattar,DO*andAmmarAhmed,MD**UniversityofIllinoisCollegeofMedicine–Peoria,DepartmentofEmergencyMedicine,Peoria,IL CorrespondenceshouldbeaddressedtoNur-AinNadir,MD,MHPEatnurainnadir@yahoo.comSubmitted:March2,2017;Accepted:March9,2017;ElectronicallyPublished:April15,2017;https://doi.org/10.21980/J8GW2N

Sectionbreak

ABSTRACT:Audience:TheHalloweenLateralCanthotomyModel”isdesignedtoinstructEmergencyMedicineresidentsPGY1-4,aswellasEmergencyMedicine-boundstudents.Introduction: Although uncommon, retrobulbar hemorrhage associatedwith facial trauma is a potentialcauseofpermanentvisionlossduetoorbitalcompartmentsyndrome.1Topreventvisionloss,treatmentwith lateral canthotomy is time-sensitiveand to perform thisprocedure inanemergent setting requiresproperlytrainedpractitioners.1Objectives:Thepurposeofthemodelistoteachresidentsandstudentshowtoperformlateralcanthotomyandtoachievecompetencyintheirskills.Methods:LateralcanthotomyisanimportantskilltobeproficientinforanyEmergencyMedicinePhysician,as it is an uncommon, sight-saving procedure. It is indicated in scenarios of facial trauma that cause aretrobulbarhemorrhage.Patientsareatriskforpermanentvisionlossduetoacuteorbitalcompartmentsyndrome if the procedure is not done expeditiously.1 A less likely cause of retrobulbar hemorrhage isspontaneoushemorrhage due toableedingdisorder oranticoagulant use.2 The featuresof retrobulbarhemorrhageincludeacutelossofvisualacuity,relativeafferentpupillarydefect,proptosiswithresistancetoretropulsion, increased intraocularpressure,and limitedextraocularmovement.3 Whilethediagnosis isclinical,itcanbeconfirmedbycomputedtomography(CT)andmeasurementofintraocularpressure.2Whenthe diagnosis is established, lateral canthotomy and cantholysis should be performed emergently.Cantholysis is contraindicated when a globe rupture is suspected or with an orbital blowout fracture.Potential complications of this procedure include iatrogenic injury to the globe or lateral rectusmuscle,damage to the elevator aponeurosis resulting in ptosis, injury to the lacrimal gland and lacrimal artery,bleedingandinfection.3Thistasktrainerusesaffordablematerialstoletlearnerspracticethisrare,visionsavingprocedure.Topics:Visualacuity,eyetrauma,retrobulbarhemorrhage,relativeafferentpupillarydefect.

USER GUIDE

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Linkedobjectives,methodsandresults:Learnersareexpectedtocometothissessionpreparedwithpre-readingontheprocedure.Facultysolicitindications,contraindicationsandcomplicationsofthisprocedurefromlearners(objective1)andthenproceedtoexplainanddemonstratetheperformanceoftheprocedure.Facultythendirectlyobservelearnersperformingtheprocedure(objective2)andproviderealtimefeedback.Recommendedpre-readingforinstructor:

• BallardSR,EnzenauerRW,O’DonnellT,etal.Emergencylateralcanthotomyandcantholysis:asimpleproceduretopreservevisionfromsightthreateningorbitalhemorrhage.JSpecOperMed.2009;9(3):26-32.https://www.jsomonline.org/Publications/2009326Ballard.pdf

• KnoopKJandDennisWR.OphthalmologicProcedures.In:RobertsJR,ed.RobertsandHedges'ClinicalProceduresinEmergencyMedicine.6thedition.Philadelphia,PA:Elsevier;2014.pp.1293-1295.

• http://www.foamem.com/?s=lateral+canthotomy

• www.lifeinthefastlane.com/ophthalmology-befuddler-033-203/01/2017

Learnerresponsiblecontent(LRC):

• BallardSR,EnzenauerRW,O’DonnellT,etal.Emergencylateralcanthotomyandcantholysis:asimpleproceduretopreservevisionfromsightthreateningorbitalhemorrhage.JSpecOperMed.2009;9(3):26-32.https://www.jsomonline.org/Publications/2009326Ballard.pdf

• KnoopKJandDennisWR.OphthalmologicProcedures.In:RobertsJR,ed.RobertsandHedges'ClinicalProceduresinEmergencyMedicine.6thedition.Philadelphia,PA:Elsevier;2014.pp.1293-1295.

• http://www.foamem.com/?s=lateral+canthotomy• www.lifeinthefastlane.com/ophthalmology-befuddler-

033-203/01/2017ImplementationMethods:

• Thismodelisbestutilizedinsmallgroupsessionswithfacultytostudentratiosof6:1to8:1.

• Facultyfacilitateeachsmallgroupsessionthroughinitialdiscussionoftheindications,contra-indicationsandcomplicationsoflateralcanthotomy.Theyfollowthisbyexplainingtheprocedureanddemonstratingitsperformanceonthetasktrainer.Subsequentlytheyobservelearnersperformingtheprocedureandproviderealtimefeedbackonitsperformanceusingachecklist.

Listofitemsrequiredtoreplicatethisinnovation:

1. CelebrityorPerson(notmonster)Halloweenmasks(availableAmazon.com:https://www.amazon.com/gp/product/B003C1APBS/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1)Tip:Tobecost-effective,planthisactivityimmediatelyafterHalloweenbecausemasksonAmazonaswellasvariouspartystoresgoonsaleandcanbepurchasedeconomically,hencethenameofthemodel.

2. Ping-pongEyeBalls(availableatAmazon.com:https://www.amazon.com/gp/product/B00EO94V08/ref=oh_aui_search_detailpage?ie=UTF8&psc=1)

3. WhiteHairTies0.3cmdiameter,preferablyflatnottubular,availableatClaire.com(oranysuperstore).

4. Styrofoammanikinhead(availableatAmazon:https://www.amazon.com/Hatop-Styrofoam-Mannequin-Manikin-Glasses/dp/B01N78EQQB/ref=sr_1_20_a_it?ie=UTF8&qid=1488479198&sr=8-20&keywords=white+flat+hair+rubber+band)

5. Scissors

LearnerAudience:EmergencyMedicine-boundMedicalStudents,EMInterns,JuniorResidents,andSeniorResidents,aswellasOpthalmologyResidents TimeRequiredforImplementation:Preparation:

• Eachmodeltakesabout10minutestoassemble.Didactics:

• Eachproceduretakes1minute.Eachlearnerhastheabilitytopracticeoncantholysingtheinferiorandsuperiorcrusofthelateralcanthalligament.

Learnersperinstructor:• 2learnerspermodel–oneforeacheyeandabout

6-8learnerspersmallgroupsession.Topics:Visualacuity,eyetrauma,retrobulbarhemorrhage,RAPD.Objectives:Bytheendofthisinstructionalsessionlearnersshould:

1. Discusstheindications,contraindicationsandcomplicationsassociatedwiththeprocedure.

2. Beabletoperformcantholysisvialateralcanthotomyonsimulatedmodels.

USER GUIDE

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6. Needleandthreadtosuture7. Thumbtacks8. BinderClips9. Lacerationrepairtray(forperformingprocedure)

Approximatecostofitemstocreatethisinnovation:$7-8*permodel(dependsonthepriceofthemasks,tip:searcharoundforthecheapestmasksavailableastheytendtofluctuateinprice).Detailedmethodstoconstructthisinnovation:

Step1:InverttheHalloweenmask.Findthelateralcornerofthemaskseye-holes.Step2:Stitchthewhitehairtietothelateralcornersinthefashiondepictedsoastosimulatebothsuperiorandinferiorcrusofthelateralcanthalligament.

Step3:Taketheping-pongballeyeandinsertitintothebackofthemask.Makesurethatthisissnug.

Step4:Applythemasktoamanikin–weusedStyrofoammanikinheads.Ensurethatthemaskisonfirmly.Youcanusethumbtacksandbinderclipstodrawittightlyacrossthemanikinface.

Supplies((

Halloween(Mask(

Halloween(Ping2pong((eye(balls(

Manikin(head(

White(Hair(Tie(Scissors(

Needle(with(thread(

Step%1%

•  Invert%the%mask%•  Cut%the%hair%3e%and%s3tch%it%lateral%corners%of%the%eye%hole%

Superior%crus%%lateral%canthal%ligament%

Inferior%Crus%lateral%canthal%%ligament%

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Step5:Repeatforothereye.

Step6:Proceedwithprocedureusingthesetupprovided.Holdthemanikinheadtopreventitfromrollingwhileperformingtheprocedure.

Resultsandtipsforsuccessfulimplementation:Thisexerciseisbestimplementedinsmallgroupsessionswithafacultytolearnerratioof6:1or8:1.Feedbackfrom36learnerswasoverwhelminglypositive.14of36learnerscompletedevaluationsand57%ofthemreportedpost-laboratorycomfortlevelsat4-5/5on5-pointLikertscale.Therestreportedcomfortlevelsat3/5ona5-pointLikertscale.Withrespecttosatisfactionwiththemodelitself,57%oflearnersratedthelateralcanthotomymodelata4/5ona5-pointLikertscale.Another35%oflearnersreportedthemodelata5/5.Feedbackfromcommentsshowedsomeinterestinpracticingmeasurementofintraocularpressureduringthislaboratory.Therefore,thisextracomponentwillbeaddedtofuturelaboratoriesbyincludingtonometryasaseparatedistinctstationwithintheprocedurelaboratory.Tip1:Foroptimalperformanceofprocedure,theStyrofoamheadsneedtobestabilized:therefore,pair2learnerstoonemodel.Asklearner1toholdthemodelandobserve,whilelearner2performstheprocedure.Subsequentlyswitcheyesandroles.Theproceduralskillisreinforcedthroughobservationofitsperformance.Tip2:Asavariationofthisbasicmodel,sliptheHalloweenLateralCanthotomyMaskontoahigh-fidelitymanikinsimulatorinsteadoftheStyrofoamheadtouseinasimulationcase.References/suggestionsforfurtherreading:1. BallardSR,EnzenauerRW,O’DonnellT,etal.Emergency

lateralcanthotomyandcantholysis:asimpleproceduretopreservevisionfromsightthreateningorbitalhemorrhage.JSpecOperMed.2009;9(3):26-32.

2. Nickson,C.(2016).Bashed,BlindandBulging[Blogpost].Retrievedfromwww.lifeinthefastlane.com/ophthalmology-befuddler-033-2Accessed03/01/2017.

3. KnoopKJandDennisWR.OphthalmologicProcedures.InRobertsJR,ed.RobertsandHedges'ClinicalProceduresinEmergencyMedicine.6thedition.Philadelphia,PA:Elsevier;2014.pp.1293-1295.

4. Sarwark,J(2014).TheLateralCanthotomy[BlogPost]Retrievedfromhttp://www.foamem.com/?s=lateral+canthotomy.Accessed03/01/2017.