Rev. Bras. Anestesiol. vol.66 número4

REVISTA

BRASILEIRA

DE

ANESTESIOLOGIA

www.sba.com.br

SCIENTIFIC

ARTICLE

Comparing

insertion

characteristics

on

nasogastric

tube

placement

by

using

GlideScope

TM

visualization

vs.

MacIntosh

laryngoscope

assistance

in

anaesthetized

and

intubated

patients

Wan

Hafsah

Wan

Ibadullah

_,

_Nurlia

_Yahya

,

Siti

Salmah

Ghazali

,

Esa

Kamaruzaman

_,

_Liu

_Chian

_Yong

_,

_Adnan

_Dan

_,

_Jaafar

_Md

_Zain

a_{DepartmentofAnaesthesiologyandIntensiveCare,UniversitiKebangsaanMalaysiaMedicalCentre,KualaLumpur,Malaysia}

b_{DepartmentofAnaesthesiologyandIntensiveCare,HospitalKualaLumpur,KualaLumpur,Malaysia}

Received10July2014;accepted11November2014 Availableonline20October2015

KEYWORDS

Nasogastrictube; Videolaryngoscope; Directlaryngoscope; Complications

Abstract

Backgroundandobjective: Thiswasaprospective,randomizedclinicalstudytocomparethe success rateof nasogastrictube insertionby using GlideScopeTM _{visualizationversus direct} MacIntoshlaryngoscopeassistanceinanesthetizedandintubatedpatients.

Methods:Ninety-sixASAIorIIpatients,aged18---70yearswererecruitedandrandomizedinto twogroupsusingeithertechnique.Thetimetakenfrominsertionofthenasogastrictubefrom thenostriluntilthecalculatedlengthoftubehadbeeninsertedwasrecorded.Thesuccessrate ofnasogastrictubeinsertionwasevaluatedintermsofsuccessfulinsertioninthefirstattempt. Complicationsassociatedwiththeinsertiontechniqueswererecorded.

Results:Theresultsshowedsuccessratesof74.5%intheGlideScopeTM_{Groupascomparedto} 58.3%intheMacIntoshGroup(p=0.10).Forthefailedattempts,thenasogastrictubewas suc-cessfullyinsertedinallcasesusingrescuetechniques.Thedurationtakeninthefirstattemptfor bothtechniqueswasnotstatisticallysignificant;GroupAwas17.2±9.3sascomparedtoGroup B,withadurationof18.9±13.0s(p=0.57).Atotalof33patientsdevelopedcomplications dur-inginsertionofthenasogastrictube,39.4%inGroupAand60.6%inGroupB(p=0.15).Themost commoncomplications,whichoccurred,werecoiling,followedbybleedingandkinking.

Conclusion: ThisstudyshowedthatusingtheGlideScopeTM_{tofacilitatenasogastrictube} inser-tionwascomparabletotheuseoftheMacIntoshlaryngoscopeintermsofsuccessfulrateof insertionandcomplications.

©2015SociedadeBrasileiradeAnestesiologia.Publishedby ElsevierEditoraLtda.Thisisan openaccessarticleundertheCCBY-NC-NDlicense( http://creativecommons.org/licenses/by-nc-nd/4.0/).

∗_{Correspondingauthor.}

E-mail:nurlia@ppukm.ukm.edu.my(N.Yahya).

http://dx.doi.org/10.1016/j.bjane.2014.11.013

PALAVRAS-CHAVE

Sondanasogástrica; Videolaringoscópio; Laringoscopiadireta; Complicac¸ões

Comparac¸ãodascaracterísticasdeinserc¸ãodesondanasogástrica,usando

visibilizac¸ãopelolaringoscópioGlideScope®_{vs.guiadapelolaringoscópioMacIntosh}

empacientesanestesiadoseintubados

Resumo

Justificativaeobjetivo:Estefoiumestudoclínicoprospectivoerandômicoparacomparara taxadesucessodainserc¸ãodesondanasogástrica(NG)usandoastécnicasdevisibilizac¸ãopelo GlideScope®_{versusguiadapelolaringoscópioMacIntoshempacientesanestesiadoseintubados.}

Métodos: Foramrecrutados96pacientes,ASAIouII,entre18-70anos,edivididos randomi-camente em dois grupos, com uma ou outra técnica. Foi calculado o tempo transcorrido desde a inserc¸ão da sonda NG, da narina até a inserc¸ão do comprimento calculado da sonda. A taxa de sucesso de inserc¸ão da sonda NG foi avaliada quanto à inserc¸ão bem-sucedida na primeira tentativa. As complicac¸ões associadas às técnicas de inserc¸ão foram registradas.

Resultados: Osresultadosmostraramtaxasdesucessode74,5%paraogrupoGlideScope®_,me comparac¸ãocom58,3%paraogrupoMacIntosh(p=0,10).Paraastentativasquefalharam,a sondaNGfoiinseridacomsucessoemtodososcasos,usandoastécnicasderesgate.Adurac¸ão daprimeiratentativaparaambasastécnicasnãofoiestatisticamentesignificativa:17,2±9,3 segundosnoGrupo Ae18,9±13,0segundosnoGrupoB(p=0,57).Nototal,33pacientes desenvolveramcomplicac¸õesduranteainserc¸ãodasondaNG:39,4% noGrupo Ae60,6%no GrupoB (p =0,15). Ascomplicac¸ões maiscomunsocorridasforamenrolamento,seguidode sangramentoedobradura.

Conclusão:EsteestudomostrouqueousodoGlideScope® _{parafacilitarainserc¸ãodesonda} nasogástrica foicomparávelao usodolaringoscópioMacIntosh quantoàtaxadesucesso de inserc¸ãoecomplicac¸ões.

©2015SociedadeBrasileiradeAnestesiologia.PublicadoporElsevierEditoraLtda.Este ´eum artigoOpen Accesssobumalicenc¸aCCBY-NC-ND( http://creativecommons.org/licenses/by-nc-nd/4.0/).

Introduction

Evenforthemostexperiencedanesthesiologist,the inser-tion of a nasogastric (NG) tube in anesthetized and tracheallyintubatedpatientscanbeverychallenging.1_The

usual methodof insertion is by ‘blindly’inserting the NG tubewiththepatient’sheadinaneutralposition,whereby success rates have been reported to vary from 40% to 58%.2---4_{Varioustechniquesof NGtube insertionhave been}

described, emphasizing the fact that as yet, there is no easy,simpleand safemethod.5_{Common methods usedto}

facilitateNGtubeinsertionincludetheuseofa‘slit’ endo-tracheal tube as an introducer, forward displacement of thelarynx, useof a ureteralguide wire asastylet, head flexion, lateral neck pressure, placing the patient’s head inthelateralposition,freezingtheNGtube withdistilled water and the use of a gloved finger to steer the NG tube after impaction.2---4,6 _{It alsohas been suggested that}

deflating the endotracheal tube (ETT) cuff will decrease esophageal compression and therefore facilitate insertion oftheNGtube.1_{However,none ofthesetechniques have}

beenreportedtobeuniversallysuccessful.

Inadditiontothesemaneuvers,theuseof visualization-aidedmodalitieshasalsobeen advocatedtofacilitate NG tube insertion. The GlideScopeTM _{videolaryngoscope is a}

reusable device that consists of a handle and a blade. Althoughthehandleissimilartothatofastandard laryngo-scope,theblade isdifferentbecauseitisnotdetachable,

hasamaximumwidthof26mmatanypoint,andhasa60◦

curvature in the midline. It includes an integrated CMOS camera;anLEDlightsource,apatentedantifogging mech-anismandreusable,medical-graderobustplasticshell.The image capturedby thecamerais displayedona7-in. liq-uidcrystaldisplaycolormonitor.Althoughacknowledgedas an effective device used for tracheal intubation,7,8 _there

are few studies done to assess the effectiveness of the GlideScopeTM _{in facilitating NG tube insertion and only a}

fewreportsmentioning itsusefulnessindoingso.5,9,10 _The

GlideScopeTM_{alsohasbeenreportedtoaidintheinsertion}

ofatransesophagealechocardiographyprobewhenallother placementmethodshavefailed.11

Studies have shown that the GlideScopeTM _provides

an improved view of the larynx as compared to direct laryngoscopy.7,8_{Oesophagealopeningvisualizationbyusing}

theMacIntoshlaryngoscopeisalsonotoptimumascompared totheuseoftheGlideScopeTM_{.Hence,insertionoftheNG}

tubeunderdirectvisionusingavideolaryngoscopemay pro-videreal-timeview,shouldhelpimprovespeedofinsertion andpotentiallyreducecomplications.

AstudybyMohararietal.1_{showedthattheGlideScope}TM

could be a safe and effective aid for NG tube insertion in anesthetized and intubated patients by improving the easeofinsertionwithasuccess rateof85%.However,the study comparedtheconventional ‘blindtechnique’versus GlideScopeTM_{assistance,whichprovidesadirectview}

NasogastrictubeinsertionusingGlideScope vs.MacIntoshlaryngoscopy 365

insertioncharacteristicsonnasogastrictube placementby usingGlideScopeTM _{visualization versusMacIntosh}

laryngo-scope assistance withregards tofirst successful attempt, rescueattemptsandcomplicationsinanesthetizedand intu-batedpatients.

Materials

and

methods

Thisprospective,randomized,single-blindedclinicalstudy wasconductedafterobtaininginstitutionalethicsapproval fromtheMedicalResearchand EthicsCommittee, Univer-siti KebangsaanMalaysiaMedicalCentre(UKMMC) (Project code: FF-199-2012) and the Clinical Research Committee ofMinistryofHealthMalaysia(NMRR-12-1010-12540).After obtaining written informed consent,a total of 96 Ameri-canSociety ofAnesthesiologists(ASA)IorII patientsaged between18and70years,scheduledforsurgeryunder gen-eralanesthesiarequiring trachealintubation andNGtube insertion were recruited into this study. Those excluded fromthestudywerepatientswithknownbasalskull frac-ture, hemorrhagic disorders, esophageal diseases such as stricture,varicesorstenosis,historyofradiotherapytothe headandneckandobesitywithabodymassindex(BMI)of morethan35kg/m2_{.Preoperatively,patientswere}

random-ized using computer-generated randomized numbers into twogroups.Themorepatentnostrilwasselectedbasedon twocriteria, theamount of foggingproduced on a metal tonguedepressorduringexhalationandtherelativesizeof thenostril.Thenostrilthatwasbiggerandproducedmore fogwaschosen. Allpatientswerepremedicatedwithoral midazolam7.5mgonthenightbeforesurgery.

Intravenousaccess(IV)wasestablishedintheoperating theater. Standard monitoring with continuous electrocar-diography, non-invasive blood pressure monitoring, pulse oximetry and capnographwere usedfor all patients. Fol-lowingpreoxygenation,inductionofanesthesiawascarried outusingIVpropofol2mg/kg,IVfentanyl2mcg/kgandIV rocuronium 0.9mg/kg. Patients were given assisted ven-tilation via facemask for 3min following which direct laryngoscopyperformed.Thepatientswereintubatedwith a size 7.5mm (for female) or 8.0mm (for male) internal diameter,polyvinylchlorideendotracheal tube(ETT).The ETTcuffwasinflatedandthepressurekeptbetween15and 25cm H2O using apressure gauge manometer. Anesthesia

wasmaintainedbyoxygen/air(50%/50%)andsevofluraneat aminimumalveolarconcentrationof1.

Multiple operators consisting of anesthesia medical officers, who were proficient in both techniques, were responsiblefortheNGtubeinsertions.InGroupApatients, thebladeoftheGlideScopeTM_{wasinsertedintothepatient’s}

mouth, the tracheal tube and tongue were lifted to pro-videtheanesthetistwiththebestviewofthelaryngealarea whichwasvisualizedonthedisplaycolormonitor andthe NGtube wasadvanced.In Group Bpatients,the bladeof theMacIntoshlaryngoscopewasinsertedintothepatient’s mouth, the tracheal tube and tongue were lifted to pro-vide the anesthetist with the best view of the laryngeal area,visualized orally and theNG tube wasadvanced. In bothgroups,thepatient’sheadwasmaintainedinthe neu-tralpositionand thebladeswere liftedgently toprevent excessiveextensionoftheneck.

Inallpatientgroups,a14Frenchgauge(FG),125cmNG tube(ForesightIndustriesSdnBhd,Selangor,Malaysia)with leadwasused.The length ofNGtube necessary to reach thestomachwasassessedbeforeinsertionandmeasuredby placingthetipoftheNGtubeonthepatient’sxiphoid pro-cessandextendingittothetipofhis/hernoseandoverthe earlobe.Immediatelybeforeinsertion,KYjellywasapplied ontheselectedpatient’snostril.Ineachgroup,theNGtube waspassed via the patient’s nostril posteriorly along the floorofthenoseandtubewasadvancedtoreachthe mea-suredlength.AsuccessfulNGtubeinsertionwasdefinedas thesuccessfulpassageoftheNGtubeinthefirstattempt andconfirmed whenthe tubepassed smoothly anda gur-glingsoundwasheardonauscultationovertheepigastrium wheninjecting10mLofairthroughtheNGtube.Inthefirst attempt,noassistingdevicewasusedinbothgroups.Ifthe NGtubewasnotsuccessfullyinserted,itwasdeemedasa proceduralfailureandrecordedasafailedattempt.TheNG tube waswithdrawn fully and cleaned. Subsequently res-cue techniques were implemented to insert the NG tube untilitwassuccessfullyinserted. Rescuetechniques com-prisedof second attempt andswitch-over technique. The sameNGtube wasusedin thesecond attempt, this time withtheassistanceofaMagill’sforceps.Ifthattoofailed, theNGtubewasreinsertedswitchingoverthe2techniques whileusingtheassistanceofaMagill’sforceps.InGroupA, theMacIntoshlaryngoscope wasusedandinGroup B,the GlideScopeTM_{wasusedinsteadtoinserttheNGtube(refer}

toFig.1forthestudyflowchart).

No assisting device

Success xx

Fail Success

Success

Fail

Fail Fail

Group A Use GlideScopeTM

Group B

Use macintosh laryngoscope Randomization

No assisting device

Success

Use magill forcep

Use macintosh laryngoscope

Use magill forcep

Success Fail Success Fail

Failed use rescue technique

Switch-over technique

Inclusion

Use GlideScopeTM

Thedurationrequiredforplacementwastakenfromthe timewhenthetubewasadvancedintothenostriluntilthe measuredlengthofthetubehadbeeninserted.Ageneral anesthesiaassistant measured the timetaken using stop-watch.The occurrenceof complicationssuchasbleeding, kinking and coiling during the procedure was noted. The rateofsuccessfulNGtubeinsertionandthedurationneeded forsuccessfulinsertiononthefirstattemptwascompared betweenthe2groups.

All data were recorded and analyzed using SPSS ver-sion 21.0 software. Normal distribution of continuous data was tested by the Kolmogorov---Smirnov test. Non-parametricdata(gender,race,ASA,intubationattemptand complications) were analyzed using the Chi-square test. Independent T-test was used to analyze parametric data (age,height, weight,BMIand durationof insertion).A p -value of less than 0.05 was considered to bestatistically significant.

Results

Atotal of 96 patients were enrolledbut only 95 patients wereincluded,asonepatientfromGroup A,whoinitially consented to participatein the study, refused surgery on thedayofoperation.Forty-sevenpatientswereenrolledin GroupAand48patientsinGroupB.Thedemographicdata isshowninTable1.Thedemographicdatawascomparable betweenbothgroups.

Table2showssuccessfulinsertionsoftheNGtubeduring thefirstattemptandrescuetechniques.The NGtube was ultimatelyinsertedinallpatients.

The mean time for duration of insertion in the first attempt for Group A was 17.2±9.3s and for Group B

Table1 Demographicdata,valuesexpressedasmean±SD

ornumbern(%)whereappropriate. GroupA (n=47)

GroupB (n=48)

p-Value

Age(years) 51.7±13.3 47.0±14.2 0.11

Gender 0.35

Male 18(38.3) 14(29.2) Female 29(61.7) 34(70.8)

ASA 0.47

I 20(42.6) 25(52.1)

II 27(57.4) 23(47.9)

Weight(kg) 65.1±9.7 63.3±13.9 0.47 Height(m) 1.6±0.7 1.6±0.8 0.76 BMI(kg/m2_{) 25.4±3.6 24.9±4.6 0.54}

Table 2 Success rates of NG tube insertion, values

expressedasnumbern(%). Attempts GroupA

(n=47)

GroupB (n=48)

p-Value

1stattempt 35(74.5) 28(58.3) 0.10 Secondattempt 11(23.4) 18(37.5) 0.55 Switch-over 1(2.1) 2(4.2) 1.00

was18.9±13.0s(p=0.57).Thirty-threepatientsdeveloped complicationsduringinsertionoftheNGtube, 13patients (39.4%) in Group A and 20 patients (60.6%) in Group B (p=0.15).

The complications werefurther categorizedtocoiling, kinkingandbleeding.Elevenpatients(23.4%)inGroupAand 17patients(35.4%)inGroupBdevelopedcoiling(p=1.00). Bleeding occurred in 4 patients (8.5%) in Group A and 5 patients (10.4%)in GroupB(p=1.00). Kinkingoccurred in 2patients(4.3%)inGroupAand1patient(2.1%)inGroupB (p=0.55).OnepatientinGroupAhadaccidentalmalposition oftheNGtubeintothetrachea.Percentageofcomplications thatwascalculatedreflectstheoccurrenceofcomplications inallattemptscollectively.Onepatientmayalsohavehad morethanonecomplicationoccurringduringtheinsertion procedure.

Discussion

Ourstudywasdesignedtocomparedirectvisualization tech-niques using two different intubation devices to assist in nasogastric tube insertion. Wefound that thereappeared tobeahighersuccessrateinGroupAcomparedtoGroup B,74.5%vs.58.3%,althoughthiswasnotstatistically signif-icant.Alargersamplesizewouldmostprobablyberequired tolookforasignificantstatisticaldifferenceinthesuccess rateofinsertion.

Ourstudyshowedthattherewasnosignificantdifference inthedurationofinsertionbetweenthese2groups.Astudy donebyMohararietal.1_{showedashorterdurationof}

inser-tionintheGlideScopeTM_group(10.9

±9.0s)ascomparedto the‘blind’insertiontechniquegroup(38.6±29.0s).Afew previous studies comparing the conventional‘blind’ tech-niqueandvariousothertechniquesofinsertionshowedthat thedurationofNGtubeinsertionusingthe‘blind’technique tookbetween39.5sand124sforsuccessfulinsertion.2,4,12

Hence,directvisualizationtechniquesmayimproveNGtube insertionspeed.Infuturestudieshowever,itwouldperhaps bebettertoincludea‘blind’techniquegrouptoallow bet-tercomparison betweennewtechniques of insertionwith theconventionalmethod,toassessspeedofNGtube inser-tion.

However,in the rescue second attempt, there were a higherpercentageofpatientsinGroupBwhohadsuccessful insertionoftheNGtubealthoughthiswasnotstatistically significant.Thiscanbeexplainedbythedifficultyin manip-ulatingtheMagill’sforcepsinGroup Apatientsduetothe bulkinessoftheGlideScopeTM_{bladeallowinglimitedspace}

tomovetheMagill’sforcepsorallyascomparedtotheuse oftheMacIntoshblade.

Themostcommoncomplicationinthisstudywascoiling. Elevenpatients(23.4%)inGroupAand17patients(35.4%) inGroupBdevelopedcoiling.Thepiriformsinusesandthe arytenoidcartilagesarethemostcommonsitesofimpaction ofaNGtube duringinsertion.2_{Ithasbeen suggestedthat}

compressionoftheipsilateralneckatthelevelandlateral border of the thyrohyoid membrane canbe performed to collapsetheipsilateralpiriformfossaandslightlymovethe arytenoids cartilagesothat NGtube canpass throughvia thelateralorposteriorhypopharynx.13_Other

NasogastrictubeinsertionusingGlideScope vs.MacIntoshlaryngoscopy 367

flexionwithlateralpressure (82%success rate inthe first attempt),2_{usingneckflexion(80%successrateinthefirst}

attempt),3_{headturnedtothelateralposition(80%success}

rateinthefirstattempt),5_{andliftingthethyroidcartilage}

(68.8% success rate in the first attempt).14 _{However, for}

patients withcervicalinstability, these techniques cannot beused.Agroetal.15_{demonstratedthattheGlideScope}TM

provided a better vision of the glottis compared to the MacIntoshlaryngoscopeincervicalspineimmobilization.In anotherstudy,Maliketal.12 _{alsoshowedthatalthoughthe}

GlideScopeTM_{requiredmoretimefortrachealintubation,it}

reducedintubationdifficultyandimprovedglotticviewover theMacIntoshlaryngoscopeinpatientswithcervicalspine immobilization. Thus using the GlideScopeTM _{for NG tube}

insertionwouldalsobebeneficialincaseswhere manipula-tionoftheneckislimited.

Another complication observed was bleeding from mucosalsurface. However,therewasnostatistical differ-enceinbothgroups.Noneofthesepatientsneededfurther medicaltreatment. Itwasobserved thatthebleedingwas mostly fromthe nostril and nasopharynx areaand proba-blyoccurredduetotraumafromthetipofNGtubeduring insertionratherthantraumacausedfromthevarious tech-niquesitself.Inordertolessentheoccurrenceofbleeding, some studies preparedthe patient’s nostril with vasocon-strictors(suchasphenylephrineoroxymetazoline)priorto NGtubeinsertion.1,3_{Inourstudy,wedidnotuseany}

vaso-constrictorstopreparethepatient’snostril.Appukuttyand Shroff2_{usedaslitETTorallytoassistininsertionoftheNG}

tubeandreportedahighsuccessrateinthefirstinsertion attemptusingthistechnique.However,therewasincreased risk ofbleeding(22%) withthis techniqueascomparedto othertechniquesusedinthestudy.

AlthoughNGtubeinsertionisconsideredacommon clini-calprocedure,itcanproduceunexpectedcomplications.In ourstudy,therewasaninadvertent,accidentalplacement oftheNGtubeintothetracheaofonepatientinGroupA. This wasevidenced by bubblingof waterwhen the proxi-maltipoftheNGtubewasimmersedinagallipotofwater. The NGtube washowever,successfully inserted usingthe rescuetechnique.Rassias etal.16 _{reporteda 2%incidence}

oftracheopulmonarycomplicationssuchaspneumothorax, hydrothoraxor hemorrhageamong740NGtube insertions whereby 0.3% of patients died from thesecomplications. Pillaietal.17_{suggestedthatthepresenceoftheETTmight}

actuallyincreasetheriskofpulmonaryentryoftheNGtube duetopreventionofglotticclosure.ApreexistingETTmay distort the anatomy of the laryngeal opening due to the presenceoftheETTcuffexpandingtheglotticopening lead-ingtoanincreasedriskofnasoenteraltubemalpositionand complications.17_{ThetechniqueofdeflatingETTcuffbefore}

insertionoftheNGtubewouldbehelpfulinincreasingthe success rate of insertion asshown in studies by Moharari etal.1_andLaietal.5_{althoughbydoingso,mayleadtothe}

potentialrisk ofaspirationwhenthe ETTcuffis deflated. However,none ofthesestudiesreportedaspirationasone ofthecomplications.

TheuseoftheMacIntoshlaryngoscopewithassistanceof theMagill forcepsis theconventional rescuetechniquein theinstitutionwherethisstudywascarriedout.This tech-niquealsohasbeenusedastherescuetechniqueinmostof thestudies involvingNGtube insertion.1---3,14 _However,the

GlideScopeTM_{assistancetechniquemaybeusedasthe}

res-cuetechniqueofchoicewhenothermethodshavefailedas evidenced by the high success rate of insertion usingthe GlideScopeTM_{asshowninthestudybyMohararietal.}1_and

otherpreviouscasereports.5,9,10

There werea few limitations in thisstudy. Firstly,the potential for investigator bias exist asit is impossible to blind the anesthetists tothe device being used. Further-more,multipleoperatorswereinvolvedininsertingNGtube. Therefore,therewillalsobeskillbiasinthisstudy.Astudy byMatheison18_{whichincludedattendinganesthesiologists,}

anesthesiologistfellowsand respiratorytherapistsshowed thatafter30 intubationattempts usingthe GlideScopeTM_,

success rates of intubation were high (94.2%).Therefore, to reduce skill bias in future studies; it can be recom-mendedthatatleast30previous NGtubeinsertionsusing theGlideScopeTM_{bytheinvestigatorswouldberequiredto}

gainexpertisewithitsuse.

TheGlideScopeTM_{hasbeenusedwidelyindifficult}

intu-bationcases.Howeverforethicalreasons,casesofdifficult NGtubeinsertionduetodifficultairwaysandobesepatients were excluded from this study. Therefore, results in our study would not reflect the outcome in these groups of patients.TheadvantageofusingtheGlideScopeTM_compared

tousingtheMacIntoshbladeisthatitdoesnotrequirea line-of-sightviewfromtheoperatortotheesophagealopening. As it has been shown to beadvantageous in difficult air-waysituations,furtherstudiesusingtheGlideScopeTM_may

berecommended tofacilitate NGtube insertionin obese patientsandthosewithpotentialdifficultairwaysand cer-vicalinstability.Inconclusion,thisstudyshowedthatusing theGlideScopeTM_{tofacilitatenasogastrictubeinsertionwas}

comparable to the use of the MacIntosh laryngoscope in termsofsuccessfulrateofinsertionandcomplications.

Conflicts

of

interest

Theauthorsdeclarenoconflictsofinterest.

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