Rev. Bras. Anestesiol. vol.66 número1

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REVISTA

BRASILEIRA

DE

ANESTESIOLOGIA

OfficialPublicationoftheBrazilianSocietyofAnesthesiology

www.sba.com.br

SCIENTIFIC

ARTICLE

Teaching

practices

of

thoracic

epidural

catheterizations

in

different

grade

of

anesthesia

residents

夽

Ali

Alagoz

a,∗

,

Hilal

Sazak

a

,

Mehtap

Tunc

a

,

Fatma

Ulus

a

,

Serdar

Kokulu

b

,

Polat

Pehlivanoglu

a

_,

_Saziye

_Sahin

c

a_Department_of_{Anesthesiology}_and_Reanimation,_Ataturk_Chest_Disease_and_Thoracic_Surgery_Training_and_Research_Hospital,

Ankara,Turkey

b_Department_of_{Anesthesiology}_and_Reanimation,_Faculty_of_Medicine,_Afyon_Kocatepe_University,_{Afyonkarahisar,}_Turkey

c_Department_of_{Anesthesiology,}_Faculty_of_Dentistry,_Gazi_University,_Ankara,_Turkey

Received3July2014;accepted28July2014 Availableonline27October2014

KEYWORDS Residencytraining; Thoracicepidural catheterization; Failurerate; Complications

Abstract

Backgroundandobjectives: In this study,we aimed to clarify the importance ofresidency grade andotherfactorswhich influence thesuccessofthoracicepidural catheterization in thoracotomypatients.

Methods:Aftertheethicalcommitteeapproval,datawererecordedretrospectivelyfromthe chartsof415patients.Allpatientshadgivenwritteninformedconsent.Thethoracic epidu-ralcatheterizationattemptsweredividedintotwogroupsassecond---thirdyear(GroupI)and fourthyear(GroupII)accordingtoresidencygrade.Weretrospectivelycollecteddemographic data, characteristics ofthoracic epidural catheterization attempts, and all difficulties and complicationsduringthoracicepiduralcatheterization.

Results:Overall success rate ofthoracic epidural catheterization was similar between the groups.Levelsofcatheterplacement,numberanddurationofthoracicepiduralcatheterization attempts werenotdifferentbetweenthegroups(p>0.05).Changeofneedleinsertionlevel was statistically higherin Group II (p=0.008),whereas paresthesia was significantly higher inGroupI(p=0.007).Duralpunctureandpostdural punctureheadacherateswerehigherin Group I. Higherbody massindexandleveloftheinsertion sitewere significantfactorsfor thoracicepiduralcatheterizationfailureandpostoperativecomplicationrateandthosewere independencefromresidents’experience(p<0.001,0.005).

夽 _This_study_was_presented_as_a_poster_World_Institute_of_Pain_6th_World_Congress_of_World_Institute_of_Pain._February_4---6,_2012,_Miami

Beach,Florida,US.

∗_{Corresponding}_author.

E-mail:mdalagoz@gmail.com(A.Alagoz).

http://dx.doi.org/10.1016/j.bjane.2014.07.010

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Conclusion:Bodymassindexandlevelofinsertionsiteweresignificantonthoracicepidural catheterizationfailureandpostoperativecomplicationrate.Wethinkthatresidents’gradeis notasignificantfactorintermsoverallsuccessrateofthoracicepiduralcatheterization,but itisimportantforoutcomeoftheseprocedures.

PALAVRAS-CHAVE Treinamentoem residência;

Cateterismoepidural torácico;

Taxadefalha; Complicac¸ões

Ensinodapráticadecateterismoepiduraltorácicoemdiferentesanosderesidência emanestesia

Resumo

Justificativaeobjetivos: Neste estudo o objetivo foi esclarecer a importância do ano de residênciaeoutrosfatoresqueinfluenciamosucessodocateterismoepiduraltorácico(CET) empacientessubmetidosàtoracotomia.

Métodos: Apósaaprovac¸ãodoComitêdeÉtica,osdadosforamretrospectivamenteanalisados apartirdosprontuáriosde415pacientes.Todosospacientesassinaramostermosde consen-timentoinformado.AstentativasdeCETforamdivididasemdoisgrupos:segundo-terceiroano (GrupoI)equartoano(GrupoII),deacordocomoanoderesidência.Dadosdemográficos, car-acterísticasdastentativasdeCETetodasasdificuldadesecomplicac¸õesduranteoCETforam registradosretrospectivamente.

Resultados: A taxade sucesso global de CETfoi semelhante entre osgrupos. Os níveis de colocaçãodocateter,onúmeroeaduraçãodastentativasnãoforamdiferentesentreosgrupos (p>0,05).A alteraçãodoníveldeinserçãodaagulhafoiestatisticamentemaiornoGrupoII (p=0,008),enquantoqueaparestesiafoisignificativamentemaiornoGrupoI(p=0,007).As taxasdecefaléiaduranteeapóspunçãoduralforammaioresnoGrupoI.Umíndicedemassa corporal(IMC)maioreoníveldolocaldeinserçãoforamfatoressignificativosparaofracasso doCETeparaastaxasdecomplicaçõesnopós-operatório,masindependentesdaexperiência dosresidentes(p<0,001,0,005).

Conclusão:OIMCeoníveldolocaldeinserc¸ãoforamsignificativosparaofracassodoCETe paraastaxasdecomplicac¸õesnopós-operatório.Pensamosqueoanoderesidêncianãoéum fatorsignificativoemtermosdetaxadesucessoglobalparaoCET,maséimportanteparao resultadodessesprocedimentos.

Introduction

Asamethodofchoiceforanalgesicmanagementofthoracic and upperabdominal surgery, thoracic epidural catheter-ization (TEC) is one of the most difficult procedures in anesthesiapractice.1 _Although _TEC _is _a _gold _standard _for

thoracotomypain,itisrelatedtospecificcomplicationsand contraindicationswhichmaylimitits’usage.1---4 _The

estab-lishmentofbalancebetweenanesthesiaresidencytraining and safety of patients is ongoing dilemma in anesthesia interventions,especiallyinTEC.5,6_The_TEC_may_also_become

complicated due to anatomical difficulty and variations. Residencygradeand previous experiencemight be impor-tantfactorsinachievingsuccessfulTECattempt, whereas noexactcriteriahave been mentioned asregardsto tim-ingforinitiationof TECtraining.7---9_In _general,_anesthesia

residents have sufficient experience on spinal anesthesia andlumbarepiduralcatheterizationbeforetheTEC train-ing, but learning curve of TEC attempts is uncertain.8---11

WhetherresidentseducatedlumbarepiduralbeforeTECor notwasnotanimportantfactorforexperience.12_TEC_is_also

secureandeasytoteachwithaverylowincidenceofserious complications.12 _To_the_best_of_our_knowledge,_the_articles

evaluating regionalanesthesiatraining of anesthesia resi-dents,inparticularfocusingonTEC,havebeenlimited.In thisstudy,weaimedtoclarifytheimportanceofresidency gradeandotherfactorswhichinfluencethesuccessofTEC inthoracotomypatients.

Methods

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Table1 Demographicdata andAmericanSociety ofAnesthesiology (ASA)physicalstatusofpatients intermsofresidency grade.

Variables Group1(n=203)(mean±SD) Group2(n=212)(mean±SD) p

Age(year) 49.2±15.7 52.6±14.5 0.020a

Gender 0.436

Male 157(77.3%) 157(74.1%)

Female 46(22.7%) 55(25.9%)

BMI(kg/m2₎ _25.4_±_4.0 _25.3_±_4.3 _0.899

DistributionbyBMI(kg/m2₎ _0.546

18.5 7(3.4%) 7(3.3%)

18.5---25 92(45.3%) 103(48.6%)

25---30 76(37.4%) 66(31.1%)

>30kg 28(13.8%) 36(17.0%)

ASA 0.560

I 3(1.5%) 1(0.5%)

II 106(52.2%) 113(53.3%)

III 94(46.3%) 98(46.2%)

GroupI,2nd---3rdyearresidents;GroupII,4thyearresidents;BMI,bodymassindex;ASA,AmericanSocietyofAnesthesiology.Demographic

datawerepresentedasmean±SDanddistributionofBMI,gender,andASAwerepresentedasnumericalvaluesandpercentage.

a _p_<_0.05,_comparison_between_groups.

weredividedintotwogroupsassecond---thirdyear(GroupI) andfourthyearresidencygrade(GroupII).

All interventions, including TEC, which performed by theresidentshavebeen achievedunderthesupervisionof staff anesthesiologists.The failed process wasdefined as 3sequentialunsuccessfulattemptsorinterventionslasting morethan15min,Touhyneedlerelatedduralpuncture,and persistentbleedingfromcatheterorneedle.IncaseofTEC failure,thestaff anesthesiologistperformed thoracic par-avertebralblock at the endof surgery, and postoperative analgesia was provided with multimodal analgesia tech-niques.

We retrospectivelycollecteddemographicdata, Ameri-canSocietyofAnesthesiology(ASA)physicalstatus,thelevel andanychangeoftheinsertionlevel,durationandnumber

of TEC attempts, and all difficulties during TEC. We also reviewedpaincharts for thesatisfaction ofpain manage-ment,TECrelatedpostoperativecomplicationswhichwere includedkinking,obstructionanddislodgementofthe tho-racic epidural catheter, hypotension, post dural puncture headache(PDPH),hyperemiaatthecatheterinsertionsite, andipsilateralshoulderpain.

Statistical analysis was performed using SPSS 11.5 for Windows. Descriptive statistic was expressed as mean±standard deviation,andcategoricalvariableswere expressed as case number and percentage. Student-t

test was performed to compare mean values in groups. Pearson’s chi-square, Fisher’s exact test, chi-square or likelihoodratiowereperformedtoevaluatethecategorical variables. The effect of residents’ experience, patients’

Table2 Characteristicsofthoracicepiduralcatheterization(TEC).

Variables GroupI(n=203) GroupII(n=212) p

Touhyneedleinsertionlevel 0.257

Thoracic4---5 55(27.1%) 53(25.0%)

Thoracic5---6 50(24.6%) 42(19.8%)

Thoracic6---7 42(20.7%) 61(28.8%)

Thoracic7---8 56(27.6%) 56(26.4%)

Numberofattempts 0.320

1 93(45.8%) 91(42.9%)

2 48(23.6%) 42(19.8%)

3 62(30.5%) 79(37.3%)

a_Duration_of_TEC_attempts_(min) _0.715

0---5 101(49.8%) 99(46.7%)

5---10 66(32.5%) 77(36.3%)

10---15 36(17.7%) 36(17.0%)

GroupI,2nd---3rdyearresidents;GroupII,4thyearresidents.

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Table3 Patients’satisfactionanddifficultiesrelatedtothoracicepiduralcatheterization.

Variables GroupI(n=203) GroupII(n=212) p

Numberofinsertionlevelchange 46(23.0%) 72(35.0%) 0.008a

Bleedingb ₁₆_(8.0%) ₁₅_(7.3%) _0.785

Duralpuncture 3(1.5%) 1(0.5%) 0.366

Difficultyofcatheteradvance 4(2.0%) 7(3.4%) 0.386

Paresthesia 7(3.5%) --- 0.007a

ComplicationsduringTEC 25(12.5%) 20(9.7%) 0.370

TECfailurerate 18(8.9%) 19(9.0%) 0.973

Patients’satisfaction 0.857

Excellent 103(50.7%) 102(48.1%)

Good 61(30.0%) 66(31.1%)

Moderate 36(17.8%) 42(19.8%)

Bad 3(0.15%) 2(0.1%)

TEC,thoracicepiduralcatheterization;Datawerepresentedaspatients’numberandpercentage.GroupI,2nd---3rdyearresidents;

GroupII,4thyearresidents.

a_p_<_0.05,_comparison_between_groups.

b _Bleeding_through_epidural_catheter_or_Touhy_needle.

age, body mass index (BMI), and level of insertion site on complication during TEC, procedure failure, and TEC relatedpostoperativecomplicationswereanalyzedbyusing Univariate Logistic Regression analyses. The effect of all probableriskfactorsoncomplicationduringTEC,procedure failure,andTECrelatedpostoperativecomplicationswere analyzed byMultivariate Logistic Regression analysis.Odd ratio(OR)and95%confidenceinterval(CI)werecalculated foreachvariables.Statisticallysignificantdifferenceswere acceptedasp<0.05.

Results

Average age of patients was slightly higher in Group II (p<0.020). There was no significant difference in

terms of gender, BMI, and ASA physical status (p>0.05) (Table1).

Differences in the Touhy needle insertion level, num-ber and duration of TEC attempts were not significant betweenthegroups(p>0.05)(Table2).Thenumberof nee-dleinsertionlevelchangewasstatisticallyhigherinGroupII (p=0.008).Paresthesiafrequencywassignificantlyhigherin GroupI(p=0.007).Therewerenostatisticallydifferencein termsofbleedingthroughepiduralcatheter,difficultyofthe catheteradvance,andfailurerate(p>0.05).Patients’ sat-isfactionswerenotdifferentbetweenthegroups(p>0.05) (Table3).Distribution ofpostoperativecomplications rate wasnotstatisticallydifferentbetweenthegroups(p>0.05). TheBMIand levelof theinsertionsiteweresignificant factorsonTECfailureandpostoperativecomplicationrate, and there were independent from residents’ experience. Postoperative complicationrate was3.196times higherin

Table4 Thecorrelation betweenresidency grade,body massindex(BMI),andthe levelofneedleinsertionandthoracic epiduralcatheterization(TEC)relatedcomplicationsandprocedurefailurerate.

ComplicationsduringTEC Procedurefailure PostoperativeComplications

OR(95%CI) p OR(95%CI) p OR(95%CI) p

Experience

4thyear 1.000 --- 1.000 --- 1.000

---2nd---3rdyear 1.329(0.712---2.478) 0.953 1.022(0.499---2.095) 0.953 0.947(0.464---1.933) 0.882

BMI(kg/m2₎

<18.5 1.000 1.000 1.000

18.5---25 1.630(0.338---7.861) 0.543 1.535(0.172---13.718) 0.701 0.857(0.100---7.318) 0.888 25---30 1.770(0.904---3.465) 0.096 2.985(1.172---7.150) 0.021a _0.905_{(0.373---2.194)} _0.825

>30 0.686(0.223---2.111) 0.511 5.673(2.186---14.728) <0.001a _3.196_{(1.372---7.447)} _0.007a

Insertionlevel

T7---8 1.000 1.000 1.000

T4---5 2.099(0.891---4.943) 0.090 2.025(0.559---7.334) 0.282 0.660(0.209---2.088) 0.480 T5---6 1.528(0.604---3.867) 0.371 3.420(1.008---11.601) 0.049a _2.904_{(1.190---7.088)} _0.019a

T6---7 0.977(0.362---2.639) 0.963 5.204(1.647---16.449) 0.005a _0.704_{(0.237---2.094)} _0.528

OR,oddsratio;CI,confidenceinterval;TEC,thoracicepiduralcatheterization;BMI,bodymassindex.

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obesepatientsaccordingtonormalweightpatients(95%CI: 1.372---7.447;p=0.007).

PostoperativecomplicationratewasalsohigherinT5---6 groupwhencomparedtheT7---8group(OR,2.904;95%CI: 1.190---7.088;p=0.019)(Table4).TheTECfailureratewas significantly higherin overweight patient(OR, 2.985;95% CI:1.172---7.150),(p=0.021)andobesepatients(OR,5.673; 95%CI: 2.186---14.728),(p<0.001) whencomparedto nor-malweightpatients.FailureratewasalsoincreasedinT5---6 level(OR,3.420;95%CI:1.008---11.601;p=0.049)andT6---7 (OR,5.204;95%CI:1.647---16.449; p=0.005),accordingto T7---8 level (Table 4). There was no correlation between complicationduringTECandresidentsexperience,patients’ age,BMI,andlevelofinsertionsite(p>0.05)(Table4).

Conclusion

Inpresentstudy,retrospectiveanalysisof415TECattempts showed that BMI and level of insertion site were con-siderable factors for procedure failure and postoperative complicationrate.Althoughabsenceofseriousneurological complications, paresthesia wasmore frequent in 2nd---3rd residents.DuralpunctureandPDPHrateswerealsohigher inthisgroup.

Various reports have been published to determine the sufficientepiduralcatheterattemptsforresidencytraining, butnumberofattemptstoachieveadequateexperienceis still unclear.5,8,9,12 _According _to _the _{Accreditation} _Council

forGraduateMedicalEducation,residentsshouldperform50 epiduralcatheterizationsduringtraininginanesthesiology.13

On the other hand, at least 20---25 epidural blocks are necessary to achieve consistency in residency training in anesthesiology.9_Recommended_minimum_number_of_lumbar

epiduralcatheterizationpriortoTECtraininginliteratures islimited.Inourdepartmentallresidentsperformatleast 20lumbarepiduralcatheterinsertionsbeforetheTEC train-ing. All attempts are performed under the supervision of staffanesthesiologist.

Midlineor paramediantechniques maybepreferredfor TEC.Approximatelyfiftypercentofanesthesiologyprograms teachesbothmidlineandparamedianapproachesinUnited States.12 _Midline _approach _had _a _higher _success _rate _and

required fewerattempts thanthe paramedian approach.9

Inanotherstudy,researchersdidnotfoundanydifferences in success ofthe firstattempt or numberof attempts for eithertypeof block,regardlessofthe approach.14

Advan-tagesordisadvantagesofmidlineorparamedianapproach during TEC have been mentioned by the authors.12,15 _We

preferredmidlineapproachandourresidentswere comfort-ablewhileusingthisapproachandhanging-droptechnique forTEC.Lossofresistantandhanging droptechniquesare usedtodetectepiduralspace.Hangingdroptechniquewas safe andcomfortable onsitting positiondue tohigh neg-ative pressure at thoracic level.16 _We _also _performed _all

catheterizations in sitting position by using hanging-drop technique.

No exact criteria have been mentioned in the articles intermsofdurationandnumberofTECattempttodefine theprocedurefailure.Twounsuccessfulattemptsorsingle attemptrequiredmorethan10minwasdeterminedas pro-cedure failurein alarge numberlumbar andlow-thoracic

epiduralcatheterization study.17 _In _the _present _study, _we

definedthefailureas3unsuccessfulattemptsorthe proce-durelastingformorethan15min.Ourcriteriaforprocedure failureweremoreflexiblethanthisstudyduetotechnical difficultiesofmid-thoracicTEC.17

TheBMIisoneofthemostimportantfactorsfor epidu-ralcatheterization.Correctidentificationoftheanatomical landmarksinTEC is thefirststep forsuccessful catheter-ization without severe complications. Main challenges in performing regional anesthesia in obese patients are the appropriate landmark identification, the correct patient positioning,and the useof appropriate equipment.18 _The

lack ofthese issuesmay increase thefailure ratein neu-roaxialblockade.Ourstudyindicatedthatthesuccessrate of TEC was converselycorrelated in overweight or obese individuals,anditwasindependentfromresidencygrade. We thinkthat subcutaneous fat tissuemight affect nega-tivelytheidentificationoflandmarkinobeseandoverweight patients.

Mid-thoracicepidural catheterinsertionis adequate to provideanesthesiaandpostoperativeanalgesiaforthoracic surgery.14 _Extreme _upward _{angulations’}_of_the _Touhy

nee-dlemakes insertion more difficult particularly in the mid andhigh thoracicregions.18 _To _the_best_of _our_knowledge

norecommendation about success rate of TEC related to level of insertion site in mid-thoracic region in articles. Weperformed allTEC placements at mid thoracic levels, andwefound significant differenceswithrespecttolevel ofinsertionsite.ComparedtoT7---8level,failureratewas morefrequentinuppermid-thoracicregions.Itcouldreflect thedifficulty of procedure at higher mid-thoracic region. Advancedresearchesmaybehelpfultoidentifytheoptimal levelforinsertionincludedthisarea.

The TEC related complications is in a wide range, but neurological injuries are the most crucial complica-tionin anesthesia practice.Due topotential neurological sequel,the risk-benefit ratio of thoracic epidural analge-sia is controversial.3 _Our _results _showed _that _the _rate _of

neurologicalcomplicationswasquite low.Paresthesia was observed only 7 patients included in 2nd---3rd year resi-dents group. Dural puncture and PDPH were also higher in this group. Even if success rate of TEC is similar in groups, the high frequency of paresthesia and PDHD couldexplaintheimportanceofexperienceandresidency grade.

Untilnow,theassociationsbetweenthenumberofTEC attempts and operator experience have been studied by the investigators, but no definitive information was pro-vided.Inonestudy,first-yearresidentssuccessfullylocated the epidural space in 76% of cases.9 _An _another _study

either did not find a significant association between the level of training and first-level success.14 _We _found _that

thenumber of TEC attempts washigher in 4thyear resi-dentsgroup.Consideringsafetyandtraumaduringepidural attemptsmightbehelpfultoeliminatethecomplications. Less traumatic procedure may be related to operator’s experience.19 _We _think _that _the _number _of _attempts

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In conclusion, TEA is one of the major components ofthoracicand thoraco-abdominalanesthesiaand postop-erative pain management. In our study, BMI and level of insertionsiteweresignificant factorsonprocedure failure and postoperative complication rate. These factors were independentfromresidents’grade.Previouslumbar epidu-ral and spinal block experience couldbe helpful for high success rate on TEC. The incidence of technical difficul-ties, procedure-related complications, and postoperative complications were quite low during TEC. Although suc-cess rate of TEC was similarin both groups, TEC related complications rate was higher in 2nd---3rd year group. It shouldberelatedtoexperienceandresidents’grade.

Conflicts

of

interest

Theauthorsdeclarenoconflictsofinterest.

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