w w w . j c o l . o r g . b r
Journal
of
Coloproctology
Original
Article
Safety
degree
assessment
of
drugs
used
in
conscious
sedation
for
colonoscopy
in
patients
that
develop
respiratory
depression
夽
Fernanda
Maraschin
Rech
a,∗,
Kaiser
de
Souza
Kock
b,
Amanda
Colpani
Bellei
aaUniversidadedoSuldeSantaCatarina(UNISUL),CursodeMedicina,Tubarão,SC,Brazil bUniversidadedoSuldeSantaCatarina(UNISUL),FaculdadedeMedicina,Tubarão,SC,Brazil
a
r
t
i
c
l
e
i
n
f
o
Articlehistory:
Received19September2016 Accepted20September2016 Availableonline11November2016
Keywords: Colonoscopy Conscioussedation Complication Sedation
Respiratorydepression
a
b
s
t
r
a
c
t
Objective:Toanalyzethesafetydegreeofdrugsusedincolonoscopyduringconscious seda-tioninpatientsdevelopingrespiratorydepression.
Methods:Cross-sectionalobservationalstudythatevaluated1120patientswhounderwent colonoscopybetweenFebruary2015andFebruary2016.Physicalcharacteristics,surgical historyandpreviouscolonoscopies,indicationandconditionsofthecurrentexamination, fentanylandmidazolamdosesandsubsequentcomplicationswereanalyzed.Levelof sig-nificance:p<0.05.Chi-squaretestwasusedforassociationofcategoricalvariables,whereas Student’sttestwasusedtocomparemeansandSpearman’scoefficientforcorrelation. Results:Therewere661female(59%)and459(41%)malepatients,withameanageof54.90 (20–87)yearsandBMIof27.00(14.5–45.4).Ofthe1120patients,only2(0.2%)hadrespiratory depression,reversedwithlanexat.Patientswhohadcomplicationswereofbothgenders, withabodymassindexof21.25and28.7.Therewasacorrelationbetweentherequired doseoffentanylandage(p<0.001to−0.121Spearman’scoefficient),aswellasmidazolam (p<0.001–Spearman’scoefficient−0.452)andincreasingagewasassociatedwithalower doseofthedrug.
Conclusion: Thenumberofpatientswithcomplicationswas0.17%.Theageofthepatient showedaninverseassociation,i.e.,theolderthepatient,thelowertherequireddoseof medication. Thedrugsusedincolonoscopyshowahighdegreeofsafety,corroborating theirfrequentuseforsuperficial/conscioussedationinthisprocedure.
©2016SociedadeBrasileiradeColoproctologia.PublishedbyElsevierEditoraLtda.This isanopenaccessarticleundertheCCBY-NC-NDlicense(http://creativecommons.org/ licenses/by-nc-nd/4.0/).
夽
StudycarriedoutattheServic¸odeEndoscopiaeColonoscopia,ClínicaPró-Vida,Tubarão,SC,Brazil.
∗ Correspondingauthor.
E-mail:fermrech@hotmail.com(F.M.Rech). http://dx.doi.org/10.1016/j.jcol.2016.09.003
Avaliac¸ão
do
grau
de
seguranc¸a
dos
fármacos
utilizados
na
sedac¸ão
superficial
na
colonoscopia
em
pacientes
que
desencadeiam
depressão
respiratória
Palavras-chave: Colonoscopia,Sedac¸ão consciente,Complicac¸ão, Sedac¸ão,Depressãorespiratória
r
e
s
u
m
o
Objetivo:Analisarograudeseguranc¸adosfármacosutilizadosnacolonoscopiasobsedac¸ão superficialempacientesquedesencadeiamdepressãorespiratória.
Métodos: Estudo observacionaltransversal, queavaliou1.120pacientesquerealizaram colonoscopiaentreFevereirode 2015eFevereirode 2016.Analisaram-secaracterísticas físicas,históricocirúrgicoecolonoscopiasprévias,indicac¸ãoecondic¸õesdoexameatual, dosedefentanilemidazolamecomplicac¸õesapresentadas.Níveldesignificânciaadotado: p<0,05.Utilizou-setesteQui-quadradoparaassociac¸ãodevariáveiscategóricas,testetde Studentparacomparac¸ãodemédiasecoeficientedeSpearmanparacorrelac¸ão.
Resultados: Foram661pacientesdosexofeminino(59%)e459(41%)dosexomasculino, commédiadeidadede54,90(20-87)anoseIMCde27,00(14,5-45,4).Dos1120pacientes, apenas2(0,2%)exibiramdepressãorespiratóriarevertidacomlanexate.Ospacientesque apresentaramcomplicac¸ãoeramdesexosdiferentes,comíndicesdemassacorpóreade 21,25e28,7.Houvecorrelac¸ãoentreadosenecessáriadefentanileaidade(p<0,001 -coefSpearmann-0.121),assimcomoademidazolam(p<0,001-coefSpearmann-0.452), sendoquecomoaumentodaidadesecorrelacionoucomumamenordoseutilizadade medicamento.
Conclusão: Onúmerode pacientesqueapresentaramalgumacomplicac¸ãofoi0,17%. A idadedopacientetemassociac¸ãoinversa,quantomaioraidadedopaciente,menoréa dosenecessáriademedicamentos.Verifica-sealtograudeseguranc¸adosmedicamentos utilizadosnacolonoscopia,corroborandosuautilizac¸ãofrequenteparaasedac¸ão superfi-cial/conscientenesteprocedimento.
©2016SociedadeBrasileiradeColoproctologia.PublicadoporElsevierEditoraLtda.Este ´eumartigoOpenAccesssobumalicenc¸aCCBY-NC-ND(http://creativecommons.org/ licenses/by-nc-nd/4.0/).
Introduction
Colonoscopyisa safeendoscopic examination,which pro-videsinformation thatcommon radiological tests may not beabletodisclose.Colonoscopyhastheadvantageofbeing usedbothforthediagnosisandtreatmentofsomecolorectal diseases.1
Despiteitsimportance,patientsundergoingcolonoscopy frequentlyhavemanyquestionsandconcernsaboutthe pro-cedure.Becauseitisaninvasiveprocedure,itmayhaveits performancehinderedbyfactorssuchaspatientanxietyand discomfort,whoinadditiontofearofpain,alsomustfacethe possibilityofdiagnosisofasevereillness.2
Severalfactorsareassociatedwithincreasedlikelihoodof feelingdiscomfortduringcolonoscopy,whichcanbe inher-ent or not to the patient. Being very young or of older age, female gender, low body mass index (BMI), previous abdominalor pelvicsurgery,inadequate colon preparation, inadequatesedation,kinking,highpressureoftheairblown forcolondistentionaresomeofthesefactors.3Anexperienced endoscopist,adequatecolonpreparation,patientcompliance andeffectiveanalgesiaandsedationarerequiredforan effec-tiveandgood-qualityexamination.2–4
The best type of sedation/analgesia for gastrointestinal endoscopicprocedureshasyettobedefined,5although,itis believed thatsedation administrationbeforethe procedure
is safer for the patient and the endoscopist.6,7 Both deep sedation andsuperficialsedationandanalgesia areoptions forcolonoscopies.Whendeepersedationisdesired,usually ananesthesiologistiscalledtofollowtheexamination. Con-scious sedationallowspatients togiveverbal responsesor respondtotactilestimulationandallowscontrolofrespiratory andcardiovascularfunctions.5
Therefore,themostadequatemedicationforsedation dur-ing colonoscopyisthat withanimmediate effectand that lasts onlyforthe duration ofthe examination,resultingin a rapidpatient recoveryand causefew orno sideeffects.8 Benzodiazepinesareroutinelyusedassociatedwithopioids. Midazolam isabenzodiazepinethatreducesanxietyandis usedinpatientsedation.Ithasanonsetofactionof1–2min after intravenous administration of 5mg and has a quick recovery. Fentanyl isa short-acting opioid, ofwhich effect takes place within2minafterthe intravenous administra-tionof1–2mg/kgandisresponsibleforanesthesiaandpain reductionduringtheexamination.9
mayexperiencecrampingorseverepain,resultingfromtube movementandcanalsofeeltheurgetoevacuate.
Thecolonoscopyshouldevaluatethemucosaofallcolon segments,bothattheintroductionandthewithdrawalofthe device.Somelandmarksareusedbytheendoscopisttobetter locatethecolonoscopeduringtheprocedure.Thebluishshade ofthespleen,seenbytransparency,identifiesthesplenic flex-ure.Thesecondshade,moreextensive,consistsoftheliver andidentifiesthehepaticflexure.Theappendicularostiumis locatedinthecenterofthetriangleformedbytheconvergence ofteniaecoli,inthececum.Theilealpapillacanbeidentified throughabilabiatefoldlocatedinthetransitionbetweenthe ascendingcolonandthececum.Theexaminationis consid-eredcomplete whentheexaminer canidentifythececum, ilealpapilla andappendicular ostium and the colonoscope mustbeintroducedintheilealpapillatoevaluatetheterminal ileum.2
Thecolonoscopyperformancemayleadtocomplications arisingfromthepreparation,sedationanddiagnosticand/or therapeuticprocedures. These events,which are relatively common,haveamorbidityrateofaround 1%and are usu-allytransientandunderreported.Amongthe complications related to the drugs used for sedation are local reactions, such as superficial phlebitis atthe site of benzodiazepine injectionand localizeditching duetouse ofopioids.5 Sys-temic reactions caused by the drugs are more significant and potentially moredangerous, with mostofthem being cardiorespiratory-related.Themostcommon are: hypoven-tilation, hypertension, hypotension, hypoxia, tachycardia, bradycardia.Somemaybepotentiatedbythepainand dis-comfortofpatients,requiringhigherdosesofsedatives.6
Theaimofthis studyistoanalyze thesafety degreeof thedrugsusedincolonoscopyproceduresinpatientsunder superficialsedation,identifypossiblecomplicationsresulting fromthedrugdoses,correlatingthemwiththepresenceof complications.
Methods
Thiswasanobservationalstudywithacross-sectionaldesign, whichwasapprovedbytheResearchEthicsCommitteeof Uni-versidadedoSuldeSantaCatarinaunderopinionn.875,131, CAAE49379915.5.0000.5369,accordingtothestandardsofthe NationalHealthCouncilforresearchinvolvinghuman sub-jects,resolution466/2012.
PatientstreatedonanoutpatientbasisbetweenFebruary 2015andFebruary2016wereevaluatedattheEndoscopyand ColonoscopyServiceatClínicaPróVida,inthemunicipality ofTubarão,stateofSantaCatarina,Brazil.Basedonthe num-berofmonthlyconsultationsattheservice,ofapproximately 100consultations/month,itwasestimatedasampleof1000 patients.
Thestudyincludedallpatientssubmittedtocolonoscopyat theEndoscopyandColonoscopyServiceatClínicaPróVidain Tubarão,SantaCatarina,fromFebruary2015toFebruary2016. Patientswhorequiredemergencyexaminationsorwhowere submittedtodeepsedationwereexcludedfromthisstudy.
Allpatients receivedadietwithoutresidues ontheday beforethe examination,followedbya12-h fasting.Onthe
dayofthecolonoscopy,colonpreparationwasperformedwith a balanced polyethylene glycol solution, 1000mL adminis-teredorally3hbeforetheexamination,associatedwiththe antiemeticdrugondansetron,8mgorally.
Midazolamatadoseof0.1mg/kgofweightandintravenous fentanyl,1mcg/kg,wereusedforpatientsedationand anal-gesia,immediatelybeforetheexamination.Inpatientsolder than70years,theinitialdoseofmidazolamwas0.05mg/kg. Drugswereadministeredsimultaneouslyandaseconddose ofmidazolamwasadministeredincaseswherethepatient expressedpain,usuallyhalfoftheinitialone,0.05mg/kg.
Monitoring of vital signs was carried out with pulse oximetryand,whennecessary,oxygensupplementationwas provided with a mask. The criterion used for respiratory depressionwasarespiratoryrate<8–10bpmordecreased oxy-gen saturation (SpO2)recorded in pulse oximetry. Patients
with oxygen saturation ≤70% were treated for respiratory depression.Sedationandmonitoringwereperformedbythe endoscopistsparticipatinginthestudy,allofwhichwere pro-fessionalswithmorethan10yearsofexperience.Thedevices usedforthecolonoscopywerePentax®EPK1000Series.
Data were collected througha MedicalRecord for Anal-ysis,containingage,gender,weight,height,BMI,indication (diagnosticortherapeutic)andreasonforcolonoscopy(which disease wastobeinvestigatedand/ortreatedorwhattype oftreatmentwasused),iftherewaspriorabdominaland/or pelvicsurgeryandpreviouscolonoscopyexaminations,time ofexamination,adequate or inadequatecolon preparation, complete or incompleteexamination, doseoffentanyl and midazolamusedandsubsequentcomplications,ifany.
The drugs used for sedation and analgesia during the examinationaretheonesroutinelyusedinproceduresatthe EndoscopyandColonoscopyServiceofClínicaPróVida,inall patientssubmittedtocolonoscopy.Thestudydidnotrequire thesigningofthefreeandinformedconsentformandused onlyajustificationfornotusingtheTermofInformedConsent incasesofresearchusingmedicalrecords.
Data were recordedinaspreadsheet usingthe EpiInfo® program,version3.5.4andanalyzedwiththeprogramSPSS, version 20.0.Thesignificancelevelwasset atless than5% (p<0.05).Thedescriptionofthevariableswasperformedusing meansandstandarddeviationsfornumericalvariables and relativefrequenciesforcategoricalvariables.Thechi-square testwasusedfortheassociationofcategoricalvariables,while Student’sttestwasusedforthecomparisonofmeans and thecorrelationofvariablesusedSpearman’scorrelation coef-ficient,withrho()between−1and+1.
Results
Ofthe1120patientsevaluated,661werefemales(59%)and459 (41%)males,withameanageof54.90(20–87)years.Themean BMIofthepatientswas27(14.5–45.4),withameanheightof 163cmandmeanweightof67.38kg.
Table1–Generalaspectsofpatientssubmittedto colonoscopyunderconscioussedationinaprivateclinic inTubarão(SC).
Characteristics Number(%)
Gender
Female 661(59.0%)
Male 459(41%)
Age(mean)
<54.87years 478(42.7%)
≥54.87years 642(57.3%)
BMI
<18.5 15(1.3%)
≥18.5<25.0 372(33.3%)
≥25.0<30.0 463(41.3%)
≥30.0 270(24.1%)
Previouscolonoscopy
Yes 252(22.5%)
No 868(77.5%)
Colonpreparation
Adequate 1102(98.4%)
Inadequate 18(1.6%)
Completeexamination
Yes 1077(96.2%)
No 43(3.8%)
BMI,bodymassindex.
Table2–Indicationsforcolonoscopyunderconscious sedationinaprivateclinicinTubarão(SC).
Indication Frequency(%)
Abdominalpain 316(28.2%)
Intestinalbleeding 229(20.5%)
Changeinbowelhabit 160(14.3%)
Familialscreening 150(13.4%)
Historyofcolorectalcancer/polyposis 49(4.4%)
Indicationnotmentioned 36(3.2%)
Anemia 33(3%)
Intestinalinflammatorydisease 40(3.6%)
Oncologicfollow-up 40(3.6%)
Follow-uppost-polypectomy 29(2.5%)
Weightloss 16(1.5%)
Proctalgia/tenesmus 12(1.1%)
Endometriosis 3(0.3%)
Pre/Postoperativeprocedure 3(0.3%)
CEAalevelalteration 2(0.2%)
Portalhypertension 1(0.1%)
Alteredrectaldigitalexamination 1(0.1%)
Total 1120(100%)
a Carcinoembryonicantigen.
complicationshadadequatecolonpreparationandacomplete examination.
Table2shows patients’ indicationsforthe colonoscopy. Ofthetotalnumberofpatients,1092(97.5%)hada diagnos-ticcolonoscopyindication and 28 (2.5%)had a therapeutic indication.Patientswithcomplicationshadanindicationfor diagnosticcolonoscopy,oneofthemduetoabdominalpain andanotherduetochangeinbowelhabits.
Table3–Listofdosesandmeansofdrugsinmgusedin colonoscopyunderconscioussedationinaprivateclinic inTubarão(SC).
Medication Total Minimum Maximum Mean
Fentanyldose 1120patients 0 0.25 0.05
Midazolamdose 1120patients 1 11 5.19
Themeannumberofpriorpelvicandabdominalsurgeries
was1.06perperson;508(45.35%)hadnotbeensubmittedto anytypeofsurgicalprocedure,while612(54.64%)had under-gonesometypeofsurgery.Ofthepatientswithcomplications, bothhadundergonesometypeofsurgicalintervention.
Regarding medications,210 patients received additional
dosesofmidazolam.Themeanmidazolamdoseadministered
to patients without complications was 5.19mg (minimum
doseof1mgandmaximumdoseof11mg),whilethemean
fentanyldosewas0.05mg(minimumdoseof0mgand
maxi-mumdoseof0.25mg).Themeandoseusedinthetwopatients
withcomplicationswas20mgofmidazolamand0.05mgof
fentanyl(Table3).
Therewasacorrelationbetweenthenecessarydoseof fen-tanyland age(p<0.001–Spearman’s coefficientof−0.121). ThenegativeSpearmancoefficientshowsaninverse associ-ation,with increasingagecorrelatingwith alower doseof fentanyl.Therewasalsoacorrelationbetweenthenecessary doseofmidazolamandage(p<0.001–Spearman’scoefficient of−0452).ThenegativeSpearmancoefficientshowsaninverse association,withincreasingagecorrelatingwithalowerdose ofmidazolam.Therewasnosignificantcorrelationbetween thedoseoffentanylandthedoseofmidazolamwithBMI.
Ofthe1120patients,1118(99.8%)didnothaveany com-plications,while2(0.2%)hadrespiratorydepressionreversed withlanexat.Patientswhohadcomplicationswereof differ-entgenders,withaBMIof21.25(malegender–1.68mand 60kg)and28.7(femalegender–1.56mand70kg).
Themeanweightinpatientswithoutcomplicationswas 73.39kg/BMI 26.51, and in cases with complications was 65kg/BMI24.97. The mean age in the cases of respiratory complicationswas72years,whereasinthosewithno com-plicationswas54.87years(Table4).
Accordingtotheanalysis,nosignificantassociationwas verifiedbetweenage,weight,BMI,doseoffentanyland mida-zolamwiththeobservedcomplications.Themeandurationof thecolonoscopyinthepatientswas7.47min.Itwasobserved that evenwith alonger colonoscope insertiontime, corre-spondingtothetimeelapsedsincetheunitwasintroduced untilitreachedthececum,itwasnotassociatedwith respira-torydepressionobservedintwopatients,inwhomthemean durationoftheexaminationwas9min.
Discussion
Table4–Correlationbetweencomplicationsandothervariablesobservedinpatientssubmittedtocolonoscopyunder conscioussedation.
Age(years) Weight(kg) BMI(kg/m2) Fentanyldose
(mg)
Midazolam dose(mg)
Withcomplication(2patients) 72 65 24.97 0.05 20.00
Nocomplications(1118patients) 54.87 73.39 26.51 0.05 5.19
pvalue 0.084 0.669 0.875 1 0.185
Total 54.9
1120
73.38 1120
27 1120
0.05 1120
5.21 1120
Thereareseveralindicationsforacolonoscopy. Contraindi-cationsareincreasinglyrestrictedandmostofthemareonly relativeones.Themostfrequentindicationsinthisstudywere abdominalpain (n=316;28.2%), intestinal bleeding(n=229; 20.5%)andchangeinbowelhabits(n=160;14.3%).According tothestudybySilvaetal.,10therearereportsofsimilar indi-cationssuchasdiarrhea,analbleedingandabdominalpain. Althoughitisaroutineexamination,ithasanon-negligible morbidity,whetherregardingthe preparation,sedation,the examinationorthetherapy.Theexaminationisoftenrequired intheelderlyand/orpatientswithcomorbidities,which con-tributestoincreasedmorbidity.
Mostscientificstudiesrelatedtocomplicationsinherentto colonoscopyaimtostudycomplicationssuchasperforation andbleeding.Thepresentstudyassessedthecomplications relatedtothedrugsusedincolonoscopy,emphasizing respira-torydepression.Itisnoteworthythat,eventhoughtherewas associatedmorbidity,colonpreparationinthisstudywas clas-sifiedasadequateinmostpatients(n=1102;98.4%).Afterall, asreportedinthestudyofHabr-Gamaetal.,11thisvariableisof utmostimportanceinthisexaminationandpossibleresulting complications.
The colonoscopies were performed under conscious sedationwithbenzodiazepinesandopioidanalgesics, admin-isteredconcomitantlytoenhancesedation.Midazolamhasa limitedeffectonthecardiovascularandrespiratorysystems, causinglittlechangeinbloodpressure(BP)andonlya tran-sientdepression.Itsmostprominentandeasilyquantifiable actionisthecentralnervoussystem(CNS)depression. Respi-ratory depression remains oneof the mostfeared adverse effectsduringanesthesiawithopioids.Itsincidenceinadults describedinthe literaturevaries widely,mainlyduetothe differentdefinitionsusedbytheauthors.2Commonly,studies considerarespiratoryratelowerthan8–10bpmordecreased oxygensaturation(SpO2)recordedinpulseoximetry.3Inthis
study,patientswithoxygensaturation≤70%weretreatedfor respiratorydepression.
Inaddition tothe sideeffects associatedtopreparation andsedation,theexaminationalsohasthepotentialtocause complications due to the air insufflation in the digestive tract,mesocolontractionandpainexperiencedbythepatient, triggering or worsening complications such as increase or decreaseinBP,bradycardia,asystoleorleadingtotheneedfor higherdosesofhypnoticsandhypoanalgesics.Meandosesof 5.19mgofmidazolamand0.05mgoffentanylwereused,with amaximumdoseofeachdrug,of11mgand0.25mg,anda minimumdoseof1mgand0mg,respectively.
Due to the sedation/examination, of1120 patients, two hadrespiratorydepressionasacomplication.Thisalteration
occurred ina minorityofpatients and waseasily resolved withtheuseoflanexat(flumazenil),withbothpatients receiv-ingoxygensupplementationthroughamask,withnoneed fororotrachealintubation.Thecriteria usedforrespiratory depressionincludedallpatientswithoxygensaturation≤70%, whorequiredintervention.Lanexatisindicatedinthe com-plete or partial reversal of the central sedative effects of benzodiazepines.Therefore,itisusedinanesthesiaand inten-sive care units. The drug aimsto counteract the sedative effectsofbenzodiazepinesforshort-durationdiagnosticand therapeuticprocedures,reestablishingspontaneous respira-tionand consciousnesstoavoidintubationandsubsequent extubation.
BP monitoring throughout the examination is crucial to prevent possible worsening of morbidities. The impor-tance of using pulse oximetry during the examination is well-established, aiming to diagnose and promptly correct decreased oxygen saturation, tachycardia or bradycardia, especiallyintheelderlyand/orinpatientswith comorbidi-ties.Thedepressedlevelofconsciousnessentailsareduction inoxygensaturation.
The present study demonstrated that regardless of all the factors that can contribute to complications during colonoscopy,ofthetotal1120patientsenrolledinthestudy, 1118(99.82%)toleratedtheexaminationverywell,withoutany complicationsordecompensationevents.
Regarding theincreasingage ofpatients undergoingthe examination and the complications, it was observed that withincreasingage,lowerdoseswererequiredforconscious sedation.12 Asmentionedintheliterature,it isnoteworthy thedirectassociationbetweenincreasedcardiovascularrisks andothercomplicationsaftercolonoscopyduetoincreased age.13 Themean weight inpatients without complications was73.39kg/BMI26.51,andincaseswithcomplicationswas 65kg/BMI24.97.Therewasnosignificantassociationbetween thedosesoffentanylandofmidazolamwithBMI.However, previousstudieswithalargernumberofcasesofpatientswith complicationsobservedthatthehighertheBMI,thehigherthe dosesusedinpatientsforconscioussedation.7
preparationand complications.Bothpatientshadadequate colonpreparationandacompleteexaminationwasattained. Asfortheassociationbetweengenderandcomplications, althoughitwasnotfoundinthisanalysis,therearearticles thatsuggestanincreasedriskofcomplicationsinwomendue togynecologicsurgeriesthatcontributetothelowertolerance ofwomentocolonoscopy.14Itisbelievedthatcolonoscopyis moredifficultinthesepatientsduetotheformationof adhe-sions,common inpatients withprevious abdominal-pelvic surgeries.
Veryoften,thetechnicaldifficultyisnotassociatedwith anypatient-relatedfactor,buttotheexaminer’sexperience. Itisknownthatmoreexperiencedendoscopistshavefewer technicaldifficultieswhenperformingcolonoscopy,14 there-fore,patients withriskfactorsforcomplicationsshould be examinedbythem,whilepatientswithaneasier examina-tion profileshould be examined byendoscopists withless experience.15Allendoscopistsparticipatinginthestudyhave morethan10yearsofexperience.
Colonoscopy can be performed without any analgesia; however, because it is an invasive procedure and many patients have anxiety and fear of pain, most endoscopy servicesuse some typeofconscioussedation, throughthe associationofbenzodiazepinesandopioids.
Midazolamisabenzodiazepinethatreducesanxietyand isusedinpatientsedationandfentanylisashort-acting opi-oid,responsible foranalgesia duringtheexamination.Both have an onset of action of approximately 2min after the intravenousadministrationandfastrecovery,16respectingthe principles of conscious sedation. Itwas observed that 210 patients received extra doses of midazolam in addition to theinitialone,butthemeanadministereddoseinpatients whohadcomplicationswasnotsignificantlyhigherthanthat administered to patients who did not receive them.Thus, the group that did not show alterations received a mean doseofmidazolam of5.19mgand the minoritywith com-plicationsreceivedadoseof20mg.Themeanfentanyldose was0.05mg,bothforpatients withand without complica-tions.
A third study, after comparing two groups of patients, one using only midazolam and the other using only fen-tanyl, showed that the group receiving fentanyl showed a higher level of satisfaction and shorter recovery time. In thisstudy,duringtheexamination,patientsinthefentanyl grouprequired fewerdecubitus changes,none had mental confusion and the duration of the procedure was signifi-cantlyshorter.15Thus,sedationandanalgesiashouldbemore customized, by previously researching the biophysical and psychologicalprofileofthepatient.Patientswithriskfactors suchasfemalegender,anxiouspatients,thosewithlowBMI couldreceiveamoreintensesedation.Respiratorydepression, regardlessoftheopioidadministrationroute,doesnotoccur abruptly.Itisacomplicationthatisalwaysaccompaniedby othercentralnervoussystemdepressionsigns,suchas seda-tion.Analgesia precedes sedation, whichin turn,precedes the respiratory depression. Still, the low rate of complica-tionsobservedinthestudydemonstratedthehighdegreeof safety ofthe drugsusedduring colonoscopy,corroborating theirfrequentuseforsuperficial/conscioussedationforthis procedure.
Conclusion
Colonoscopyis asafe examinationwhenperformed under conscioussedation,aseventhoughseveralfactorscontribute to the emergence of possible complications, in this study thenumberofpatientswithcomplicationswas0.17%,with respiratorydepression.Patientageshowedaninverse asso-ciation, i.e., the older the patient, the lower the required dose of medication. The low rate of complications in the study demonstrated the highdegree ofsafetyofthe drugs usedduringcolonoscopy,corroboratingtheirfrequentusefor superficial/conscioussedationforthisprocedure.
Conflicts
of
interest
Theauthorsdeclarenoconflictsofinterest.
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