Ultrasound-guided pectoral nerve block for pain control after breast augmentation: A randomized clinical study

CLINICAL

RESEARCH

Ultrasound-guided

pectoral

nerve

block

for

pain

control

after

breast

augmentation:

a

randomized

clinical

study

Bahadır

Ciftci

_,

_Mursel

_Ekinci

_,

_Erkan

_Cem

_Celik

_,

_Pelin

_Karaaslan

_,

˙Ismail

Cem

Tukac

a_{IstanbulMedipolUniversity,DepartmentofAnesthesiologyandReanimation,Istanbul,Turkey}

b_{ErzurumRegionalTrainingandResearchHospital,DepartmentofAnesthesiologyandReanimation,Erzurum,Turkey}

Received15April2019;accepted3October2020 Availableonline25December2020

KEYWORDS Breastaugmentation surgery;

Regionalanalgesia; Pectoralnerveblock type-1

Abstract

Backgroundandobjective: PectoralnNerve(PECS)blocktype-1isanUltrasound(US)-guided interfacialblockthatcanbeperformedforpostoperativeanalgesiamanagementafterbreast surgery. In the procedure, a local anesthetic solution is injected into the interfacial area betweenthePectoralisMajormuscles(PMm)andPectoralisminormuscles(Pmm).Thepresent studycomparedPECSblocktype-1administeredpreoperativelyorpostoperativelyfor postop-erativeanalgesiaafterbreastaugmentationsurgery.

Methods: Thepatientswererandomlydividedintothreegroups(n=30ineach):a preoper-ative PECSblockgroup(Pregroup), postoperativePECSblockgroup(Postgroup),andcontrol group(GroupC).OpioidconsumptionandVisualAnalogueScale(VAS)scoreswereevaluatedat postoperativeperiod.

Results: Thepains scoresinthePregroupwere significantlylowerthanthoseinthecontrol group.AlthoughtherewasnosignificantlydifferenceintheVASscoresofthePostgroupand controlgroupatpostoperative1hour,thescoresinthePostgroupweresignificantlylowerthan thoseinthecontrolgroupatalltheotherevaluatedtimes(p<0.05).TheVASscoresinthe PregroupweresignificantlylowerthanthoseinthePostgroup8hoursafterthesurgery.Opioid consumptionwassignificantlylowerinthePregroupascomparedwiththatintheothertwo groups(p<0.05).TheuseofrescueanalgesiainthePregroupwassignificantlylowerthanthat intheothergroups(p<0.05).

Conclusion: PerformingPECSblocktype-1preoperativelyreducedVASscoresandopioid con-sumptionafterbreastaugmentation.

© 2020 Sociedade Brasileira de Anestesiologia. Published by Elsevier Editora Ltda. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/ licenses/by-nc-nd/4.0/).

∗_{Correspondingauthor.}

E-mail:bciftci@medipol.edu.tr(B.Ciftci).

https://doi.org/10.1016/j.bjane.2020.12.004

©2020SociedadeBrasileiradeAnestesiologia.PublishedbyElsevierEditoraLtda.ThisisanopenaccessarticleundertheCCBY-NC-ND

Introduction

Aesthetic breastaugmentation is a commonprocedure in plastic surgery for cosmetic reasons. It may also be per-formed after breast cancer surgery.1 _{Moderate-to-severe}

painmayoccurduringthepostoperativeperiodduetothe

insertionofsubpectoralprosthesesintothebreasttissueand

surgicaldissectionofthetissues.2_{Althoughopioiddrugsare}

generallyusedforpostoperativepainmanagement,

Opioid-RelatedAdverse Events (ORAEs) mayoccur. These include

nausea,vomiting,sedation,itching,urinaryretention,and

extendedhospitalstays.3_{Noveltechniqueshavebeen}

inves-tigated for reducing ORAEs and providing more effective

analgesia.4

PectoralNerve(PECS)blocktype-1maybeusedfor

post-operative paintreatment following breast surgery. It is a

novelinterfacialblock,whichwasfirstdescribedbyBlanco

in2011,5_{andiseasytoperformunderUltrasound(US)}

guid-ance.InPECSblocktype-1,theinterfascialregionbetween

the pectoral muscles (Pectoralis Major [PMm] and Minor

[Pmm])isinjectedwithalocalanesthetic.Apreviousstudy

reportedthatthisblockmayprovideeffectivepostoperative

analgesiaaftersubpectoralbreastaugmentation.5

Several studieshave addressed postoperativeanalgesia

managementfollowingbreastaugmentation.6---9_Anumberof

studieshavealsoinvestigatedtheefficacyofPECSblockfor

postoperative paintreatment following different types of

breastsurgery,suchascarcinoma,reconstructive,and

cos-meticsurgeries.10---14_{However,tothebestofourknowledge,}

thereisnostudythatevaluatesthetiming(preoperatively

orpostoperatively)ofthePECSblockintheliterature.

The aim of this study was to evaluate the efficacy of

PECSblocktype-1administeredatdifferenttimes(pre-or

postoperative)forpostoperativepainmanagement

follow-ingbreastaugmentation.The primaryoutcomewasopioid

consumptionduringthefirstpostoperative24hoursperiod.

The secondary outcomes were pain scores (Visual Analog

Scale --- VAS), rescue analgesic consumption, and adverse

effects.

Patients

and

methods

Thisstudyincluded90femalepatients(agedbetween18and 65 years)whowereAmerican Societyof Anesthesiologists (ASA)statusI---IIandunderwentsubpectoralbreast augmen-tationundergeneralanesthesia.Patientswhohadahistory ofbleedingdiathesis;anticoagulanttreatment;skin infec-tions at the procedure region; majorcardiac, pulmonary, renal,orliverdysfunction;thoracalabnormalities;orknown allergiestolocal anestheticdrugs andopioidagents were excluded.Lactationorpregnancyandunwillingnessto par-ticipatewereadditionalexclusioncriteria.

Priortotheirarrivalintheoperationroom,thepatients wererandomlydividedintothefollowingthreegroupsusing a computer program, with 30 patients in each group: a preoperative PECSgroup(Pregroup),a postoperativePECS group(Postgroup),andacontrolgroup(GroupC).

This study was approved by the Istanbul Medipol Uni-versity ethics committee. Written informed consent was obtainedfromallthepatients.

Generalanesthesia

The patients were monitored as normal (electrocar-diography, noninvasive blood pressure and peripheral oxygen saturation). A dose of 1---2 mg of midazolam was administered intravenously (IV) for premedication. Gen-eral anesthesia was induced by the administration of 2---2.5mg.kg-1_{ofpropofol,1---1.5mcg.kg}-1_{offentanyl,and}

0.6mg.kg-1_{ofrocuroniumIV,followedbyorotracheal}

intu-bation. Mechanical ventilation was initiated with a tidal volume of 6---8 mL.kg-1_{, fresh gas flow rate of 2 L.min}-1_,

end-tidalCO230---35mmHg,andpeakairwaypressureof30

cmH2O.Anesthesia wasmaintainedusing sevofluranein a

mixtureofoxygenandfreshair,andaremifentanilinfusion IV(0.25 mcg.kg-1_{. min}-1_{)wasbegun. The patients’ heart}

rates,respiratoryrates,peripheraloxygensaturation, non-invasivearterial pressures, and end-tidal CO2 levelswere

recorded at 5-minute intervals during the surgery. Addi-tional analgesia intraoperatively wasprovided with a 0.5 mcg.kg-1 _{bolus ofremifentanylanda 50%increase inthe}

concentrationofsevofluraneifthepatient’sheartrateand meanarterialpressureexceeded20%ofthebaseline.Inall cases,breastaugmentationwasperformedusinga subpec-toralprosthesis,andthesamesurgicalteamperformedall theprocedures.

Adoseof0.5mg.kg-1_{oftramadolIVwasadministeredto}

allthepatients20minutesbeforetheendoftheoperation. Attheendofthesurgery,theneuromuscularblockadewas antagonizedusingatropine(0.01mg.kg-1_{)andneostigmine}

(0.02mg.kg-1_{)administeredIV.Thepatientswereextubated}

aftersufficientspontaneousrespirationwasobserved.They werethentransferredtothepostanesthesiacare unitand transferredtothewardwhentheyscored12pointsonthe Aldretescoring system.PECS blockwasnotperformed for controlgroup.A1-gdoseofparacetamolwasadministered routinely every 8 hours in control group and a fentanyl patient-controlled analgesiadevice wasattachedtothem for24hoursinthepostoperativeperiod.

PECSblockprocedure

BilateralUS-guidedPECSblocktype-1wasadministratedto patientsinthepre-andpost- groups.InthePregroup,the blockprocedurewasperformedfollowinganesthesia induc-tionandintubationbeforethebeginningofthesurgery.In thePostgroup,theprocedure wasperformed before extu-bation.

Theblockprocedurewasperformedunderaseptic condi-tionsusingaVividqUSsystem(GEHealthcare,Wauwatosa, WI,USA).A 12MHzlinearUSprobewaspositionedinthe sagittal plane between the terminal end of the clavicle and the acromioclavicular joint in the first costae level. Aftervisualizingthepectoralbranchofthethoraco-acromial arterybetweenthePMmandPmmabovethefirstrib(Fig.1),

a 22-gauge 50-mm block needle (Stimuplex Ultra 360; B.

Braun,Melsungen,Germany)wasinsertedintothe

interfas-cialarea(Fig.2).5_{Oncetheneedletipwasplacedwithinthe}

interfacialplane,2mLofsalinewereinjectedtoconfirmthe

injectionsite.A0.4mL.kg-1_{doseof0.25%bupivacainewas}

Figure 1 Sonographicanatomy ofPECS type-1 block. A.a. indicatesaxillaryartery.

Figure2 Ultrasoundimageofneedledirectionbetweenthe muscles(PMm,Pectoralismajor;Pmm,Pectoralisminor mus-cle).

Figure3 Spreadoflocalanestheticattheplane.LAindicates localanesthetic.

Postoperativeanalgesiamanagement

For postoperative analgesia, a 1 g dose of paracetamol wasadministeredroutinelyevery 8hours.Allthepatients receivedfentanylviaapatient-controlledanalgesiadevice using the following protocol: a 1 mL (10 ␮g.mL-1_{) bolus}

withoutaninfusiondoseanda10-minutelockouttime.An anesthetist blindedto thestudy performed the postoper-ativeevaluationusingtheVAS(0=nopain,10=themost severepain).TheVASscores(right/leftsides)wererecorded inthepostoperativeperiod(1,2,4,8,16,and24hours).

A dose of 0.5 mg.kg-1 _{of meperidine wasadministered}

whentheVASscorewas≥4. Asedationscale (0=awake and eyes open, 1 = sleepy but responds toverbal stimu-lus,2=sleepyandhardtowakeup,and3=sleepyandnot arousedbyshaking)wasusedtoevaluatethesedationlevel. Postoperativeopioidconsumptionandsideeffects (breath-ingdepression,sedation/confusion, nausea,vomiting,and pruritus)werealsorecorded.

Statisticalanalysis

Apoweranalysiswasperformedaccordingtothetotal opi-oid consumption variable. According to the analysis, the effectsize was0.59 at the 95% Confidence Interval,and thepowerwas0.99atthesignificancelevel.11,14_Thus,the

studysamplesizewassufficient.IBMSPSS20.0softwarewas

usedtoanalyzethe statisticaldata. Thedata distribution

wasanalyzedusingtheKolmogorov-Smirnovtest.Pearson’s

chi-squaretest wasusedtocomparethe categoricaldata

betweenthegroups.Aone-wayanalysisofvariancewasused

tocheckdifferencesamongthegroupsfollowedbyTukey’s

tests,atasignificancelevelof5%fornormallydistributed

continuousvariables.Descriptivestatisticswereexpressed

asthemean±SD.

Results

Thepresentstudyconsistedof90femalepatients,with30 patientsineach group.Therewere nostatistically signifi-cantintergroupdifferenceswithrespecttothedemographic data(p >0.05 for each groups)(Table 1).The results are

showninaConsolidatedStandardsof ReportingTrialsflow

diagram(Fig.4).

TheVASscores(right/leftsites)1,2,4,8,16,and24h

postoperatively were significantly lower in the Pregroup

thanin thecontrolgroup.The VASscores in thePregroup

weresignificantlylowerthanthoseinthePostgroup1,2,4,

and8hourspostoperatively.Therewasnosignificant

differ-enceintheVASscoresinthePostgroupversusthoseinthe

controlgroupinthepostoperativefirsthour.However,the

VASscores2,4,8,16,and24hourspostoperativelyinthe

Postgroupweresignificantlylowerthanthoseinthecontrol

group(p<0.05)(Table2).

Opioidconsumption1,2,4,8,16,and24hours

postoper-ativelywassignificantlylowerinthePregroupascompared

withthatintheothergroups(p < 0.05)(Table3).Rescue

analgesicuseinthePregroupwasalsolowerthanthatinthe

othergroups(p< 0.05)(Table3).

Otherthantheincidenceofvomiting,whichwashigher

Table1 DemographicdataandcomparisonofoperativeproceduresbetweenGroupC,PregroupandPostgroup. GroupC (n=30) Pregroup (n=30) Postgroup (n=30) p

Age(years) 39.10±7.26 35.60±10.43 38.70±7.51 0.226a

Weight(kg) 74.30±8.49 70.43±10.30 74.13±8.61 0.188a

Height(cm) 163.20_±6.94 163.27_±5.43 163.30_±6.93 0.998a

ASA(I/II) 21/9 26/4 20/10 0.164b

Operation(reduction/augmentation) 18/12 13/17 20/10 0.171b

Valuesareexpressedmean±standarddeviationornumber.Kg,kilogram;cm,centimeter;ASA,AmericanSocietyofAnesthesiologists. a _{p> 0.05One-WayANOVAbetweengroups.}

b _{p> 0.05Chi-squaretestbetweengroups.}

Figure4 CONSORTflowdiagramofthestudy. Table2 ComparisonofVASvaluesbetweenGroupC,PregroupandPostgroup.

GroupC (n=30) Pregroup (n=30) Postgroup (n=30) p

VASright1st_{hour 5.73±1.50 3.27±1.31}a,b _{5.50±1.61 <0.001}

VASright2nd_{hour 5.50±1.19 2.47±1.30}a,b _4.03±1.65a _<0.001

VASright4th_{hour 5.03±1.12 2.00±1.17}a,c _3.17±1.28a _<0.001

VASright8th_{hour 4.63±0.99 1.57±1.07}a,b _3.03±0.99a _<0.001

VASright16th_{hour 3.87±0.97 1.47±1.07}a _1.77±1.33a _<0.001

VASright24th_{hour 3.27±0.82 0.97±0.76}a _1.33±1.06a _<0.001

VASleft1st_{hour 5.73±1.50 3.53±1.30}a,b _{5.63±1.71 <0.001}

VASleft2nd_{hour 5.47±1.16 2.70±1.23}a,c _3.93±1.55a _<0.001

VASleft4th_{hour 5.07±0.98 1.90±1.12}a,c _2.83±1.59a _<0.001

VASleft8th_{hour 4.63±0.99 1.47±1.04}a,c _2.23±1.43a _<0.001

VASleft16th_{hour 3.87±0.97 1.27±1.04}a _1.77±1.30a _<0.001

VASleft24th_{hour 3.27±0.82 0.90±0.80}a _1.20±0.96a _<0.001

Valuesareexpressedmean_±standarddeviation.VAS,VisualAnalogPainScale. a _{p<0.001OneWayANOVAcomparedwithGroupC.}

b _{p< 0.001OneWayANOVAcomparedwithPostgroup.} c _{p< 0.05OneWayANOVAcomparedwithPostgroup.}

Table3 ComparisonofopioidconsumptionandrescueanalgesiabetweenGroupC,PregroupandPostgroup. GroupC (n=30) Pregroup (n=30) Postgroup (n=30) p 1st_{hour 108.66±30.48 46.66±22.48}˛,ˇ _64.00±21.27˛ _<0.001 2st_{hour 148.66±31.81 70.33±32.00}˛,ˇ _{108.00±31.77}˛ _<0.001 4st_{hour 174.00±36.44 97.66±51.03}˛,ı _{146.66±43.41} _<0.001 8st_{hour 207.33±39.82 117.66±61.90}˛,ı _{180.66±62.25 <0.001} 16st_{hour 231.33±43.21 137.66±74.91˛,ı 211.33±76.05 <0.001} 24st_{hour 265.33±44.85 153.00±93.03}˛,ı _{236.00±91.18 <0.001}

Rescueanalgesia(Y/N) 30/0 16/14a,b _25/5aa _<0.001

Valuesareexpressedmean±standarddeviationornumbers. ␣ _{p< 0.001OneWayANOVAcomparedwithGroupC.} ␤ _{p< 0.05OneWayANOVAcomparedwithPostgroup.} ␥ _{p< 0.05OneWayANOVAcomparedwithGroupC.} ␦ _{p< 0.001OneWayANOVAcomparedwithPostgroup.} a _{p< 0.05Chi-squaretestcomparedwithGroupC.} b _{p<0.05Chi-squaretestcomparedwithgroupPostgroup.}

Table4 ComparisonofincidenceofsideeffectsbetweenGroupC,PregroupandPostgroup. GroupC (n=30) Pregroup (n=30) Postgroup (n=30) p Breathingdepression 0 0 0 1.000a Sedation/Confusion 0 0 0 1.000a Nausea(Y/N) 9 3 8 0.136a Vomiting(Y/N) 14 3b ₇b _0.005 Pruritis 2 1 2 0.809a

Valuesareexpressedasanumber.Y,Yes;N,No. a _{p> 0.05Chi-squaretestbetweengroups.} b _{p< 0.05Chi-squaretestcomparedwithGroupC.}

groups,therewerenodifferencesinadverseeffectsamong thegroups(Table4).

Discussion

This study showed that PECS block type-1 adminis-tered preoperatively decreased VAS scores and opioid consumptionfollowingbreastaugmentationsurgery. Admin-istering the block postoperatively resulted in higher VAS scores in the first hour in the postoperative period.

Varioustechniques,suchasintravenousanalgesics, tho-racic epidural analgesia, thoracic paravertebral block, intercostal blockade, and PECS blocks, may be used for postoperative pain treatment following breast augmenta-tionsurgery.6---9,14_{PECSblocktype-1iscommonlyusedunder}

US guidance because it is a superfascial block, easy to

administer,andhasrelatively lowcomplicationrates.The

mechanismofactionofPECSblocktype-1isrelatedtothe

neural anatomy of the chest wall, which contains three

groups of nerves.10 _{The medial pectoral and lateral}

pec-toral nerves form the first group. Medial pectoral nerve

rises from the medial cord of the brachial plexus and

is composed of (C8---T1) and lateral pectoral nerve rises

from the lateral cord of the brachial plexus and is

com-posedof(C5---C7).Themedialpectoralnervesarelocalized

underthePmm,andthelateralpectoralnervesarelocated

between the PMm and Pmm. These nerves innervate the

PMm andPmm.Thespinal nerves(T2---6)formthesecond

group. These are localized between the intercostal

mus-cles and support the chest wall via lateral and anterior

branches.Thefinalgroupcontainstheserratusanterior

mus-cle. The latter is innervated by the long thoracic nerve

(C5---7), and the latissimus dorsi muscle is innervated by

thethoracodorsalnerve.PECSblocktype-1targetsthefirst

neuronal group.5 _{In breast augmentation surgery,}

dissec-tionof the PMm and Pmm tofacilitate the placementof

the subpectoralprosthesis may giverise topostoperative

pain.

Althoughopioidsarecommonlypreferredforacutepain

management,ORAEsareaproblem.Anotherdisadvantage

of opioids is that they do not block the inflammatory

process.15,16 _{Thus,otheranalgesicmethods,suchas}

multi-modalorregionalanesthesia,areusedforpainmanagement

withopioids. The aimofMultimodal Analgesia(MA)

treat-ment is to provide effective analgesia and reduce the

incidence of ORAEs based on the additive or synergistic

effectsbetweendifferentanalgesics.17_{Regionalanesthesia}

techniquescanbeusedinconjunctionwithMAtodecrease

ORAEs.Anumberofpreviousstudiespointedtothesuccess

ofPECSblockforpainmanagementafterbreast

augmenta-tionsurgery.12,14_{Accordingtoourresults,PECSblocktype-1}

maybeusedeffectivelyaspartofMAfollowingbreast

aug-mentationsurgery.

Accordingtopreviousresearch,PECSblockdidnotaffect

postoperativenauseaandvomitingrates.12,13_Inthepresent

study,theincidenceofvomitingwaslowerinthePECSblock

reduceduse opioids. Crosetal. reportedthatPECS block

type-1didnotprovideanalgesia.18 _{However,intheirstudy,}

axillary lymph node dissection was performed during the

surgery,in additiontoamastectomy.Duetotheneuronal

supply of the chest wall,10 _{performingPECS block type-1}

maynotprovideanalgesiafollowingaxillarydissection.5_The

resultsofthepresentstudysupporttheideathatPECSblock

type-1isanidealanalgesictechniquefollowingbreast

aug-mentation.

The aimofpreemptiveanalgesiaistotreatpainbefore

thebeginningofapainfulstimulus.19_{Preemptiveanalgesia}

isadministeredbeforetissuedamagetopreventperipheral

andcentralsensitizationmechanisms.20_{Ifpaintransmission}

isblockedbeforeasurgicalincision,postoperative

hyperal-gesiacanbeprevented.21 _{Inthepresentstudy,PECSblock}

type-1wasperformedpreoperativelyandpostoperativelyto

determinetheoptimumtimingofthenerveblock.

Accord-ingtoour results,opioid consumption,and painscores in

thegroupinwhichtheblockwasperformedpreoperatively

werelowerthanthoseinthePostgroup.Furthermore,the

VAS scoresin thepreoperative nerve blockadministration

group werelower thanthose inthe postop group 8hours

after surgery. These results support the hypothesis that

decreasingthenumberofstimulireachingthecentral

ner-voussystemfromthenociceptorsviatheadministrationof

localanestheticagentspreoperativelypreventsthe

devel-opmentofpain.21 _{Ontheotherhand,1houraftersurgery,}

the VASscores in thegroup inwhich thenerve blockwas

administeredpostoperativelywerehigherthanthoseinthe

groupinwhichitwasadministeredpreoperatively.A

suffi-cienttimeintervalisrequiredforlocalanestheticstostart

acting.21_{Reducedpainscoresintheearlyhoursaftersurgery}

enableearliermobilizationandamelioratepatientanxiety

duetopain.

Thisstudyhassomelimitations.First,painwasevaluated

onlyduringthefirst24hoursaftersurgery,andchronicpain,

which may have long-term consequences, was not

moni-tored.Second,thestudiesinvolvingadministrateddifferent

volumesanddosesoflocalanestheticsmaybeperformed.

Third,nosensorytestingwasperformedtodemonstratethe

block.Furtherstudiesareneeded.

Conclusion

In summary, performing PECS block type-1 preoperatively reducedopioidconsumptionandprovidedlowVASscoresin patientsunderwentbreastaugmentationsurgery.

The authorsreportnoconflictsofinterest.Theauthors alone are responsible for the content and writing of the paper.

Thereisnofundingfortheresearch.

Conflicts

of

interest

Theauthorsdeclarenoconflictsofinterest.

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