REVISTA
BRASILEIRA
DE
ANESTESIOLOGIA
OfficialPublicationoftheBrazilianSocietyofAnesthesiologywww.sba.com.br
SCIENTIFIC
ARTICLE
Ultrasound
and
nerve
stimulator
guided
continuous
femoral
nerve
block
analgesia
after
total
knee
arthroplasty:
a
multicenter
randomized
controlled
study
Fen
Wang
a,
Li-Wei
Liu
a,
Zhen
Hu
a,
Yong
Peng
a,
Xiao-Qing
Zhang
b,
Quan
Li
a,∗aDepartmentofAnesthesiology,ShanghaiTenthPeople’sHospital,TongjiUniversitySchoolofMedicine,Shanghai,China bDepartmentofAnesthesiology,TongjiHospital,TongjiUniversitySchoolofMedicine,Shanghai,China
Received23May2013;accepted9July2013 Availableonline29October2013
KEYWORDS Arthroplasty; Replacement; Knee; Ultrasound; Nervestimulator; Continuousfemoral nerveblock
Abstract
Backgroundandobjectives: Postoperativeanalgesiaiscrucialforearlyfunctionalexciseafter totalkneearthroplasty.Toinvestigatetheclinicalefficacyofultrasoundandnervestimulator guidedcontinuousfemoralnerveblockanalgesiaaftertotalkneearthroplasty.
Methods:46 patients with ASA grade I---IIIwho underwent total knee arthroplasty received postoperative analgesiafromOctober2012toJanuary 2013. In 22patients, ultrasoundand nervestimulatorguidedcontinuousfemoralnerveblockwereperformedforanalgesia(CFNB group);in24patients,epiduralanalgesiawasdone(PCEAgroup).Theanalgesiceffects,side effects,articularrecoveryandcomplicationswerecomparedbetweentwogroups.
Results:At6hand12haftersurgery,thekneepainscore(VASscore)duringfunctionaltests afteractiveexerciseandafterpassiveexciseinCFNBweresignificantlyreducedwhencompared withPCEAgroup.TheamountofparecoxibusedinCFNBpatientswassignificantlyreducedwhen comparedwithPCEAgroup.At48haftersurgery,themusclestrengthgradeinCFNBgroupwas significantlyhigher,andthetimetoambulatoryactivitywasshorterthanthoseinPCEAgroup. TheincidenceofnauseaandvomitinginCFNBpatientswassignificantlyreducedwhencompared withPCEAgroup.
Conclusion:Ultrasoundandnervestimulator guidedcontinuous femoralnerveblockprovide betteranalgesiaat6hand12h,demonstratedbyRVASandPVAS.Theamountofparecoxibalso reduces,theincidenceofnauseaandvomitingdecreased,theinfluenceonmusclestrengthis compromisedandpatientscanperformambulatoryactivityunderthiscondition.
©2013SociedadeBrasileiradeAnestesiologia.PublishedbyElsevier EditoraLtda.Allrights reserved.
∗Correspondingauthor.
E-mail:[email protected](Q.Li).
PALAVRAS-CHAVE Artroplastia; Substituic¸ão; Joelho; Ultrassom;
Estimuladordenervo; Bloqueiofemoral contínuo
Bloqueiocontínuodonervofemoralguiadoporultrassomeestimuladordenervo paraanalgesiaapósartroplastiatotaldejoelho:estudomulticêntrico,randomizadoe controlado
Resumo
Justificativaeobjetivos: Analgesiapós-operatória éfundamentalpara oexercício funcional precocelogoapósaartroplastiatotaldejoelho.Oobjetivofoiinvestigaraeficáciaclínicado bloqueiocontínuodonervofemoralguiadoporultrassomeestimuladordenervoemanalgesia apósartroplastiatotaldojoelho.
Métodos: 46pacientes,estadofísicoASAI-III,submetidosàartroplastiatotaldejoelho, rece-beram analgesiapós-operatória de outubrode2012a janeirode2013. Em 22 pacientes, o bloqueiofemoralcontínuofoiguiadoporultrassomeestimuladordenervoparaanalgesia(grupo BFC);em24pacientes,analgesiafoiadministradaporviaepidural(grupoACP).Osefeitos anal-gésicos,efeitoscolaterais,recuperac¸ãoarticularecomplicac¸õesforamcomparadosentreos doisgrupos.
Resultados: Às6e12horasapósacirurgia,osescoresdedornojoelho(escoreEVA)duranteos testesfuncionaisapósexercícioativoepassivoforamsignificativamentemenoresnogrupoBFC quenogrupoACP.AquantidadeusadadeparecoxibnospacientesdogrupoBFCfoi significativa-mentemenoremcomparac¸ãocomogrupoACP.Quarentaeoitohorasapósacirurgia,ograude forc¸amuscularnogrupoBFCfoisignificativamentemaioreotempodeatividadeambulatória foimenorquenogrupoACP.AincidênciadenáuseaevômitoempacientesdogrupoBFCfoi significativamentemenoremcomparac¸ãoaogrupoACP.
Conclusão:Obloqueiofemoralcontínuoguiadoporultrassomeestimuladordonervo propor-cionarammelhoranalgesiaàs6e12horas,demonstradaporEVA-ReEVA-P.Aquantidadede parecoxibtambémfoimenor,aincidênciadenáuseaevômitodiminuiu,ainfluênciasobrea forc¸amuscularécomprometidaeospacientespodemrealizaratividadeambulatorialsobessa condic¸ão.
©2013SociedadeBrasileira deAnestesiologia.PublicadoporElsevierEditoraLtda.Todosos direitosreservados.
Introduction
After total knee arthroplasty (TKA), some patients usu-allydevelop moderatetosevere jointpain.Postoperative analgesia is crucial for early functional excise after TKA. Although a lot of strategies have been developed for analgesia,1,2theclinicalefficacyofthesestrategiesisstill
poorortheirsideeffectsmayinfluencethepost-operative articularrecovery.Continuous femoralnerveblock(CFNB) hasbeen successfullyappliedin theanalgesiaafter TKA.3
Accurate puncture and catheterization may increase the efficacyofblock.Inthisstudy,wesummarized theresults ofultrasoundandnervestimulatorguidedCFNBandpatient control epidural analgesia (PCEA) which were performed afterTKAfromOctober2012toMarch2013inthree hospi-talsinShanghai(TenthPeople’sHospital,TongjiHospitaland ChangzhengHospital).Thiswasaprospective,randomized, controlledstudyaimingtocomparetheanalgesiceffectof CFNBandPCEA,whichmayhelpustoidentifyabettertool foranalgesia.
Materials
and
methods
Generalinformation
ThisstudywasapprovedbytheInstitutionalReviewBoard (IRB)ofeachhospital.PatientsreceivingTKAwererecruited
intothisstudyfromOctober2012toMarch2013.Exclusion criteriaincluded:patientswereunabletosigntheinformed consentduetoproblemsinlanguageorcognition,patients receivedepiduralblock(includingpatientswhorefusedto participate,withplatelet countof<100×109/Lor coagu-lationdysfunction)andthosehad contradictionsfor CFNB (such as infection at puncture site, a history of femoral poplitealbypasssurgery)oradministrationofdrugsusedin thisstudy.Atotalof 45patients withASA gradeI---III who receivedunilateral TKAwere recruitedintopresent study (n=25inTenthPeople’sHospital;n=10inTongjiHospital;
n=10 in Changzheng Hospital). These patients were ran-domlyassignedintotwogroupsandreceivedultrasoundand nervestimulatorguidedCFNBandPCEA,respectively.There werenomarked differencesinthe demographicsofthese patientsbetweentwogroups(p>0.05)(Table1).
Methods
Table1 Demographicsofpatientsintwogroups.
Age(years) Male/female BMI(kg/m2) Timeofoperation(min)
Male Female
CFNB(n=23) 68.08±7.0 8 15 23.7±2.7 86.4±16.8
PCEA(n=22) 66.91±8.6 9 13 23.9±3.0 85.7±17.5
t(x2) t=0.52 x2=0.006 t=−0.76 t=0.64
p 0.98 0.94 0.48 0.57
HFL38x/13-6MHz Transducer) was placed at the middle pointofinguinal ligament.The pulsatileannularstructure withoutechowasthefemoralartery.Theprobemoved out-wardtoidentifyfemoralnervewhichwasovalortriangular inshape andhyperechoic. Afterlocalizing femoralnerve, puncturewasdone toward femoralnervewithcontinuous plexusblockkit(ContiplexD18G*3′′,B.Braun,Germany)and theanglebetweenneedleandskinwas30.Thestimulation currentwas1mA,wavewidthwas0.3msandfrequencywas 2Hz.Theneedlewasmodifiedslightlyuntilthequadriceps contracted obviously and/or the patella moved upward. Then,thestimulationcurrent reducedto0.3---0.5mA.The presence of contraction of quadriceps suggested that the needle was at the correct site. Before catheterization, 2% lidocaine (4mL) was injected, and the catheter was 5---7cm inward. Then,the catheter wasfixed when there wasnobloodduringwithdrawing. InPCEAgroup, epidural puncture wasdone at L2---3 intervertebral space, followed
bycatheterization.After fixing the catheter,2% lidocaine (4mL) was injected. Five minutes later, the anesthetic effectwas detected at the affected knee. After surgery, 0.2% ropivacaine (20mL) was injected via the catheter for analgesia. Then, an analgesia pump was connected (ShanghaiChengyiIndustrialCo.Ltd).InCFNBgroup,0.2% ropivacaine was injected at a rate of 8mL/h, the pulse dose of 5mLand lock-out timeof 30min. In PCEAgroup, 0.2% ropivacainewas injected at a rate of 5mL/h, pulse dose of2mLand lock-out timeof 30min. At 0.5h before surgery, intramuscular injection was done with 10mg of metoclopramide and 2.5mg of droperidol for prevention ofpost-operativevomitingandnausea.Generalanesthesia wasdone via thelaryngealmask andinduction anesthesia wasperformed with midazolam at 0.02---0.04mg/kg, fen-tanyl at 1g/kg, propofolat 1---2mg/kg and sulfonicacid cis-atracurium at 0.15mg/kg sequentially. Anesthesia was maintainedwith sevoflurane during surgery. Fentanyl and sulfonicacidcis-atracuriumwereadministeredifitwas nec-essary.Aftersurgery,patientswereroutinely treatedwith celecoxib(Pfizer,USA).Forpatientswithseverepain, pare-coxib(40mg;Pfizer, USA)wasadministeredintravenously. If non-responsive, morphine was intravenously transfused (Figs.1---4).
Observations
TheoperationtimeinCFNBgroupwasrecorded.The oper-ationtimereferredtotheintervalfromsterilizationtothe fixationof catheter.In both groups, theanesthetic effect wasevaluatedaccordingtotheresponseofaffectedknee
Femoral nerve Femoral vein
Femoral artery
Figure1 Beforepuncture.
Needle Femoral nerve
Femoral artery
Figure2 Aftersuccessfulpuncture.
Catheter
Femoral nerve
Catheter Femoral nerve
Anesthetic Anesthetic
Figure4 Injectionofdrugs.
andintactkneetostimulationat 5min afterinitial injec-tionof2%lidocaine:whencomparedwithintactkneewith obviouspain,absenceofpainsuggestsfavorableanesthesia, reducedpainindicates moderateanesthesiaand compara-blepainshowspooranesthesia.Visualanalogscore(VAS)was usedfor evaluation.At1h,6h,12h,24hand48h,VASof affectedlowerlimbatrest(RVAS),afteractiveexcise(IVAS) andcontinuouspassiveexcise(PVAS),themaximalrangeof motion(ROM),degreeofsedation,additionaldoseof pare-coxib and morphine,sleeping condition, muscle strength, sideeffects(nausea,vomiting,hypotension,chillsandlimb numbness),timetoambulatory activity,andintervalfrom surgerytodischargingweredetermined.Followupwasdone byaphysicianwhowasblindtothisstudy.
Statisticalanalysis
Statistical analysis was done according to SPSS version 20.Quantitative dataunderwenthomogeneity of variance test. Data with homogeneity of variance were expressed asmean±standarddeviation(¯X±s).Comparisonsbetween twogroupswere donewithindependentttest.Datawith heterogeneityofvariancewereexpressedasmedian (max-imum, minimum). Comparisonsbetween twogroups were performed with Mann---Whitney U test. Qualitative data werecomparedwithPersonChi-Squaretest.Theanesthetic effectwascomparedwithMann---WhitneyUtest.Avalueof
p<0.05wasconsideredstatisticallysignificant.
Results
VASandrecovery
InCFNBgroup,themeanoperationtimewas8.3±2.2min. Afterinjectionof2%lidocaine(4mL),theanestheticeffect was comparable (p>0.05). In CFNB group, good anesthe-siawasfoundin2patientsandmoderateanesthesiain21. InPCEAgroup,goodanesthesiawasfoundin1patientand moderateanesthesiain21.Theinjectionrateofropivacaine was8.1mL/hinCFNBgroup,and5.23mL/hinPCEAgroup. InCFNB group,at 6h and12hafter surgery,the IVASand PVASwerebetterthanthoseinPCEAgroup.Inaddition,in CFNBgroup,at48haftersurgery,themusclestrengthscore (4.05±0.84)wassignificantlyhigherthanthatinPCEAgroup
5
4
3
2
1
0
1h 6h 12h 24h 48h
P=0.782
F 1.91±1.76 F 2.26±1.36 F 1.78±1.20 F 2.09±1.72 F 1.59±1.40 E 1.72±2.12 E 3.55±2.11 E 3.65±1.44 E 3.22±1.83 E 1.83±1.65
P=0.01 P=0.001
P=0.353
P=0.868
CFNB PCEA
Figure5 IVASintwogroups.At6hand12haftersurgery,the IVASinCFNBgroupwas significantlylowerthanthatinPCEA group.CFNB: continuous femoral nerve block; PCEA:patient controlepiduralanalgesia.
(3.50±0.62, p=0.028).Moreover,the timetoambulatory activityin CFNBgroup wasalsoshorterthan thatinPCEA group(40.93±16.04hvs.60.55±22.91h,p<0.05)(Fig.5).
Additionaldoseofanalgesics
Theadditionaldoseofparecoxibwas640±100mginCFNB group,and 1000±240mg in PCEAgroup, showingmarked difference(X2=4.4, p=0.036). Inaddition, the additional dose of morphine, the maximal ROM, extent of sedation andsleeping state were comparable between two groups (p>0.05)(Table2).
Sideeffects
In PCEA group, side effects were evident, and the inci-denceofnauseaandvomitingwashigherthanthatinCFNB group.However,theincidencesofhypertension,chills,and lowerlimbnumbnesswerecomparablebetweentwogroups (Table2).
Discussion
Rehabilitation after TKA is an important determinant of post-operative functional reconstruction of knee. The severe pain during excise is mainly caused by quadriceps spasm.Femoralnerveinnervatestheskin infrontofknee and the quadriceps. Complete femoral nerve block may significantlyattenuatethe kneepainafterTKA, makethe quadricepsinarelaxstatusandrelievetheexciseinduced painofaffectedlimbsafterTKA.Continuousfemoralnerve blockhasspecialadvantageintheanalgesiaafterTKA.
Table2 Analgesics,sideeffectsandarticularrecoveryintwogroups.
CFNB(n=23) PCEA(n=22) p
Meaninfusionrate(mL/h) 8.1 5.23
Parecoxib(mg) 640±100 1000±240 0.036
Morphine(mg) 20±9.5 25±10.0 0.65
Nauseaandvomiting(n) 5 14 0.004
Hypotension(n) 1 4 0.141
Chill(n) 2 2 0.963
Footnumbness(n) 1 3 0.274
ROM(◦) 40.75±14.52 35.25±18.50 0.351
Musclepowerat48h 4.05±0.84 3.50±0.62 0.028
Timegettingoutofthebed(h) 40.93±16.04 60.55±22.91 0.002
Timestayinhospital(days) 12.87±1.96 13.95±1.99 0.08
ROM,rangeofmotion.
guided peripheral nerve block has very high efficiency. Fanellietal.4andFrancoetal.5independentlyperformed
prospectivestudieswithalargesamplesize,andthe effec-tive rate was as high as 94% and 98.8%, respectively. However,the efficacyof nervestimulatorisstillnot opti-mal,andmightcauseunpredictabledamagetothenerve.6
Inrecentyears,thetechniqueofultrasoundguidedfemoral nerveblockisimprovedsignificantly.When comparedwith nervestimulator,ultrasoundcandisplaythenervesand sur-roundingstructures,theanatomicvariations,thelocationof needleandthediffusionandanesthetics.7Ameta-analysis
showedthatguidednervelocationhashighersuccessrate ascompared tonerve stimulator.8 Inaddition,this
proce-dureistime-consuming,thenerveblockisrapidlyacquired andtheblockislong-lasting.9Studies alsorevealthatthis
procedurehasbetterblockefficiency,reducesthedoseof localanesthetics usedand decreases the risk for damage toblood vessels.10,11 Ina systemicallyretrospective study,
the anesthetic effect was compared between ultrasound guidednerveblockandtraditionalnervestimulatorguided nerveblock.Resultsshowedthattheanestheticeffectwas comparablewhen theseprocedures weredone by experi-enced physicians.12 Liu etal.13 found that there were no
markeddifferencesinthe failurerate ofnerveblock,the degree of satisfaction and the severity of post-operative neurological symptoms after ultrasound and nerve stimu-latorguided nerveblock. This might be attributedtothe highsuccess rateof both proceduresconducedby experi-encedphysicians,andthereislittlespaceforimprovement of success rate. Currently,few studies arecarried out to investigateultrasoundandnervestimulatorguidedfemoral nerveblock.Inthepresentstudy,ultrasoundandnerve sti-mulatorguidedfemoralnerveblockwereperformedafter TKA,aimingtoidentifyanidealanalgesicmethodafterTKA. Continuous epidural analgesia has definite effective-ness, and few systemic side effects. It has been widely appliedin clinical practice. However, this procedure still causes hypotension, intestinal obstruction, urinary reten-tion, motor block, and walk limitation.14 To prevent
peri-operative deep vein thrombosis in patients receiv-ing TKA, anti-coagulation therapy (such as rivaroxaban) is usually performed at the second day after surgery. Rivaroxaban is an oral medication and specifically, selec-tivelyanddirectly inhibitXafactor,whichthensuppresses
the transformation of prothrombin intothrombin preven-ting thrombosis.15 After treatment with rivaroxaban, the
incidences of total venous thrombosis and major venous thrombosis are lower than those after treatment with enoxaparin.16,17 However, meta analysis showed that the
mean incidence of bleeding was 7% after rivaroxaban treatment, which was higher than that after enoxaparin treatment.16,17delaFuenteetal.18 foundthattherewere
no thrombosis related complications and death within 30 days after surgery, but the markers of hypercoagulable statereducedtodifferentextentsafterepiduralanalgesia. Rivaroxabantreatmentincreasesthepossibilityofepidural hematoma,14whichsignificantlylimitsthewideapplication
ofepiduralanalgesia.
Inthepresentstudy,theanalgesiceffectwascompared betweenpatientsreceivedultrasoundandnervestimulator guided continuous femoral nerve analgesia and epidural analgesia after TKA. Results showed the VAS was compa-rable at 1h after surgery. This may be attributed to the incompletedisappearanceof analgesiainduced bygeneral anesthetics, and the analgesic effect of 0.2% ropivacaine reaching a peak. In CFNB group, the VASs during active exciseandpassiveexciseat6hand12haftersurgerywere markedlylowerthanthoseinPCEAgroup,suggesting that CFNB has better analgesia, especially in relieving motor pain.Underthe CFNB,thenerveand needlecanbe iden-tified,andthecathetercanaccuratelyplaceonthesurface offemoralnerve,whichassuresthat thelocalanesthetics diffusearoundthefemoralnerve.19Thismaysimultaneously
block femoralnerve,lateralfemoralcutaneous nerveand obturator nerve,16 which significantly attenuates the rest
pain and motion pain of affected limbs. Ultrasound and nervestimulatorhavecomplementaryadvantagesfor local-ization. Nerve puncturewasdone undervisualization and nervestimulatorwasusedtoinducequadricepscontraction andelevationofthepatella,whichassurethesuccessrateof punctureandsignificantlyshortenthetimeforpuncture.20
Inourstudy,theoperationtimewas8.3±2.2min,whichwas markedlyshorterthanthatundertheguidancewithnerve stimulatoralone20(11.5
isbeneficialfor thepreventionofdeepveinthrombosis.21
Thus,thisprocedureis especiallysuitablefor oldpatients whoareusuallybedriddenandhavepoorgeneralcondition. Generally, 0.2% ropivacaineis used in continuous femoral nerveblock,andthemaximaldoseisnomorethan800mg within24h.22Scottetal.23foundthatthemotornerveblock
ofropivacainewaspositivelyrelatedtoitsconcentration, and 0.2% ropivacaine couldachieve the balancebetween optimalanalgesiaandminimalmotionblock.Incontinuous femoralnerveblock,ropivacaineatalowconcentrationis usuallyused,whichhasdefiniteanalgesic effectandlittle influence on muscle strength. In CFNB group, the muscle strengthscoreat48haftersurgerywassignificantlyhigher thanthatinPCEAgroup,andthetimetoambulatory activ-ity was also shortened, which reduces the complications relatedtoprolongedbedrest.AfterTKA,favorablefemoral nerve block may provide similar or even better analge-sia than epidural analgesia, and have lower incidence of complications.24,25 When compared with PCEA group, the
favorable femoral nerve block induced analgesia reduced therequireddoseofparecoxib,which,ononehand,reduce thesideeffectsofanalgesics,andontheotherhand, atten-uatetheeconomicburdenofpatients.
InCFNBgroup,theincidenceofnauseaandvomitingwas significantlylowerthanthatin patientsreceivingepidural analgesia,26 which might be attributed to increased dose
of morphinein PCEAgroup.In addition,bleedingwasnot observedintwogroups, butpatientstreatedwith rivarox-aban paid more attention to the epidural analgesia. One patientinCFNBgroupand3patientsinPCEAgroup devel-oped foot numbness on the first day of surgery, which resolvedspontaneously,butevidentdamagetonerveswas notobserved.Studieswithlarge samplesizeshowed, dur-ingtheultrasoundandnervestimulatorguidedlocalization forperipheralnerveblock,theincidenceoftoxiceventsof local anesthetics was0/9069, and theincidence of nerve injurypersistent formore than1year wasveryrare.27 Of
note,theultrasonographyishighlydependentontheskillof operators,28 andultrasoundcannotcompletelyabolish the
possibilityofdamagetonerves.29Thus,physiciansstillpay
attentiontothesideeffectsofthisprocedure.
At 6hand12hafterTKA,theVASin patientsreceiving ultrasoundandnervestimulatorguidedcontinuousfemoral nerveblock(CFNB)foranalgesiawassignificantlylowerthan thatinpatientsreceivingepiduralanalgesia,andrequired smaller amount of parecoxib. In addition, CFNB had less influence onmuscle strengthand patients receivingCFNB hadshortertimetoambulatoryactivityandlowerincidence ofnauseaandvomiting.Thus,CFNBisanidealmethodfor analgesiaafterTKA.
However, the duration of this study was still short, andthe long-term effectofanalgesia indifferent waysis requiredtobecloselymonitored.WhetherCFNBcanreduce thedamagetonerveisrequiredtobedeterminedinfuture studies.
Funding
This studywassupported financiallyby theShanghai Edu-cationCommitteeKeyProject(13ZZ024)andPh.D.Mentor CultureProject(12HBBD109).
Conflicts
of
interest
Theauthorsdeclarenoconflictsofinterest.
Acknowledgements
Wearegratefultoallauthorsofthepublicationsincluded inthisstudyforcontributinginformation,asrequired.The authorsdeclarethatthereisnoconflictofinterest.
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