RevBrasAnestesiol.2015;65(4):302---305
REVISTA
BRASILEIRA
DE
ANESTESIOLOGIA
OfficialPublicationoftheBrazilianSocietyofAnesthesiology www.sba.com.brCLINICAL
INFORMATION
Ultrasound-guided
paravertebral
block
for
pyloromyotomy
in
3
neonates
with
congenital
hypertrophic
pyloric
stenosis
Javier
Mata-Gómez,
Rosana
Guerrero-Domínguez
∗,
Marta
García-Santigosa,
Antonio
Ontanilla
DepartamentodeAnestesiologíayReanimación,HospitalUniversitarioVirgendelRocío,Sevilla,Spain
Received9January2014;accepted13March2014 Availableonline28April2015
KEYWORDS
Pyloromyotomy; Paravertebralblock; Hypertrophicpyloric stenosis;
Regionalanesthesia; Pediatrics
Abstract
Backgroundandobjectives: Hypertrophicpyloricstenosisisarelativelycommonaffectionof gastrointestinaltractinchildhoodthatresultsinsymptoms,such asprojectilevomitingand metabolicdisordersthatimplyahighriskofaspirationduringanestheticinduction.Inthisway, thecarryingoutofatechniquewithgeneralanesthesiaandintravenousrapidsequence induc-tion,preoxygenationandcricoidpressurearerecommended.Afterthecorrectionofsystemic metabolicalkalosisandpHnormalization,cerebrospinalfluidcankeepastateofmetabolic alka-losis.Thiscircumstance,inadditiontotheresidualeffectofneuromuscularblockingagents, inhalantanestheticsandopioidscouldincreasetheriskofpostoperativeapneaafterageneral anesthesia.
Casereport: Wepresentthesuccessfulmanagementin3neonatesinthoseapyloromyotomy wascarriedoutbecausetheyhadpresentedcongenitalhypertrophicpyloricstenosis.This pro-cedure was doneundergeneral anesthesiawith orotrachealintubation andrapid sequence induction.Then,ultrasound-guidedparavertebral blockwas performedasanalgesic method withouttheneedforadministratingopioidswithinintraoperativeperiodandkeepingan appro-priateanalgesiclevel.
Conclusions:Localanesthesiahasdemonstratedtobesafeandeffectiveinpediatricpractice. Weconsidertheultrasound-guidedparavertebralblockwithonedoseasapossiblealternative forotherlocaltechniquesdescribed,avoidingtheuseofopioidsandneuromuscularblocking agentsduringgeneralanesthesia,andreducingtheriskofcentralapneawithinpostoperative period.
©2014SociedadeBrasileiradeAnestesiologia.PublishedbyElsevier EditoraLtda.Allrights reserved.
∗Correspondingauthor.
E-mail:[email protected](R.Guerrero-Domínguez). http://dx.doi.org/10.1016/j.bjane.2014.03.012
Ultrasound-guidedparavertebralblockforpyloromyotomyin3neonates 303
PALAVRAS-CHAVE
Piloromiotomia; Bloqueio paravertebral; Estenosehipertrófica depiloro;
Anestesiaregional; Pediátrica
Ultrasound-guidedparavertebralblockforpyloromyotomyin3neonateswith congenitalhypertrophicpyloricstenosis
Resumo
Justificativaeobjetivos: A estenose hipertrófica do piloro é uma condic¸ão relativamente comum do trato gastrintestinal na infância, que causa um quadro de vômitos em jato e alterac¸õesmetabólicasqueenvolvemumaltoriscodeaspirac¸ãoduranteainduc¸ãoda aneste-sia.Assim,recomenda-searealizac¸ãodeumatécnicasobanestesiageraleinduc¸ãointravenosa desequênciarápida,pré-oxigenac¸ãoepressãocricoide.Apósacorrec¸ãodaalcalosemetabólica sistêmicaenormalizac¸ãodopH,olíquidocerebrospinalpodemanterumestadodealcalose metabólica.Isto,juntamentecomosefeitosresiduaisdeagentesbloqueadores neuromuscu-lares,anestésicoseopioides,podeaumentaroriscodeapneiapós-operatóriaapósanestesia geral.
Casosclínicos:Apresentamosomanejobemsucedidoem3recém-nascidosqueforam submeti-dosapiloroplastiaporapresentarestenosehipertróficadopilorocongênita.Oprocedimento foi realizadosobanestesiageralcomintubac¸ãoorotraquealeinduc¸ãodesequênciarápida. Emseguida,realizou-seum bloqueioparavertebralguiadoporultrassonografiacomométodo analgésicosemanecessidadedeadministrac¸ãodeopioidesduranteoperíodointraoperatório emantendoonívelanalgésicoadequado.
Conclusões: Aanestesia regionalécomprovadamente segurae eficaznaprática pediátrica. Consideramosobloqueioparavertebralguiadoporultrassomcomdoseúnicacomoumapossível alternativaaoutrastécnicasregionaisdescritas,evitandoousodeopioidesebloqueadores neu-romuscularesduranteaanestesiageralereduzindooriscodeapneiacentralnopós-operatório. ©2014SociedadeBrasileira deAnestesiologia.PublicadoporElsevierEditoraLtda.Todosos direitosreservados.
Introduction
Hypertrophicpyloricstenosis(HPS)isagastrointestinal dis-order inherent to childhood, withan incidence of 0.9 to 5.1/1.000cases,1anaverageageofpresentationof5weeks
and an average weightof 4kg−1. The classic clinical
pic-tureis characterizedbyprojectile vomiting,malnutrition, dehydration and electrolyte and metabolic disturbances.1
Thetreatmentofthisconditionconsistsoftheperformance ofpyloromyotomyundergeneralanesthesiaandorotracheal intubation,2whichisachallengeforanesthesiologistsgiven
the risk of bronchopulmonary aspiration,3,4 and frequent
metabolicalterationsinthecontextofageneral anesthe-sia by hyperventilation3,4 or administrationof opioidsand
neuromuscular blockers may increase the risk of central apnea. An operation under general anesthesia combined withlocoregionaltechniquescouldreducetheriskofapnea andpostoperativecomplications.3,5
Case
reports
We report 3 infants undergoing pyloromyotomy due to HPS of 30, 34 and 42days of age and weights of 3500; 3200; and 4kg respectively. On arrival at the operating roomtheyweremonitoredbynoninvasiveblood pressure, electrocardiogram, and pulse oximetry with peripheral veinchannelingundersedationwithsevoflorane5%. Intra-venous atropine0.02mg/kg−1 wasgivenaspremedication
and intravenous propofol induction was performed at a dose of 4mg/kg−1 until reaching optimal conditions for
endotracheal intubation with rapid sequence induction andcricoidpressure,withsubsequentcheckingof correct placement of endotracheal tube by capnography and volumecontrolledmechanical ventilation. Anesthesia was maintainedwithsevofloraneat1CAM.
Theparavertebraltechniquewasperformedafter induc-tion of anesthesia in the left lateral decubitus position, keepingthe right side accessible for the procedure tobe carriedout.ThematerialusedconsistedofaToshibaNemio XG®ultrasounddevicewithtransducermodelPLM-1202Sand
a23Ghypodermicneedleof25mmoflength.T8levelwas identifiedby placingtheprobetransverselyandlateral to thespinous process at this level,with costalhyperechoic acousticshadowingbeinglocatedand,subsequently,being slightly shifted cranially until identifying the pleura as a hyperechoiclineintheintervertebralspacewithposterior echowithcomettailshape;aboveit,anisoechogenicimage correspondingtotheexternalandmedialintercostal mus-cle,andoutofthis,ahyperechoiclinethatservedtomark theboundariesoftheparavertebralspace.Havingidentified thesestructurestheneedle(Fig.1)wasintroducedunder sterileconditions,lateralandmedialtotheprobewiththe tipoftheprobebeinglocatedatalltimesuntilreachingthe paravertebralspaceinfiltratingitwith0.25mL/kg−1
bupiva-caine0.25%inasinglebolusandafterpriorsuctiontorule outintravascularinjection(Fig.2).
304 J.Mata-Gómezetal.
Figure 1 Performance of ultrasound-guided paravertebral blockinapatientwithHPS.
Figure2 UltrasoundviewofparavertebralspaceatT8level.
Noepisodesofapneaintheearlypostoperative24hwere detectedandnoneofthe3infantsrequiredanalgesiainthe first12h.
Discussion
TherecurrentvomitingassociatedwithHPScausesastate ofhypochloremicmetabolicalkalosis3 andincreasedpHof
cerebrospinalfluid. Cerebrospinalfluid alkalosis may per-sistafter correctionof systemicmetabolic alkalosis.3 The
pHofthecerebrospinalfluidisoneofthedeterminantsof respiratorystimulus.3Metabolicdisturbances,
hyperventila-tion,dehydrationandtheresidualeffectofneuromuscular blockingagents,inhalantsandopioidsusedprimarilyduring theanestheticprocedure3couldincreasetheriskofcentral
apnea,increasedinpreterminfantswhoconstitute12%of cases,3 leadingtorespiratory problems that require
long-termmaintenanceofmechanicalventilation.2
Neonates are especially sensitive to the respiratory depressant effects associated with opioid analgesia. This
sensitivityappearstoberelatedtoimmaturityofthe respi-ratory muscles and respiratory control centers.3 Although
respiratory complications and incidence of apnea breaks aremore frequent in the latter, postoperativeapnea was described in healthy neonates who underwent pyloro-plasty andreceivedopioidsin the intraoperatoryperiod,3
remainingintubatedandconnectedtomechanical ventila-tionduringthepostoperativeperiod.Forthisreason,some anesthetistsrecommendlimitingtheuse ofopioidsduring pyloromyotomy.3
HPS patients are considered with ‘‘full stomach’’,1,3,4
so that a general anesthetic technique is recommended withadequatepreoxygenationandrapidsequenceinduction withcricoidpressureandorotrachealintubation4toreduce
theriskofbronchopulmonaryaspiration.Upto5%of anes-thetists recommendawake intubation tolimit the risk of aspirationandpossibledesaturation.However,itis associ-atedwithothercomplications,suchassofttissuetrauma, bradycardia,laryngospasmandhypoxia.4Inhalational
induc-tionhasbeen recommendeddue toitssafetyin pediatric patients.2,4,6
Intheneonatalperiod,theregionalanalgesiaisindicated whenourgoalisan earlyextubation.Besidesprovidingan adequate level of intraoperative analgesia and its longer durationinthepostoperativeperiod,5itprovidesadegreeof
musclerelaxationtofacilitatethesurgicaltechnique.7The
need for postoperative ventilatory support is significantly reduced7 whenlocoregional analgesic techniques are
per-formed,comparedwiththeadministrationofintraoperative opioiddrugs,decreasingthedurationofmechanical venti-lationandminimizingrespiratorycomplications,whichthus reducesthemorbidityandmortality.7
For locoregional anesthetic technique performance, knowledge oftheexact locationofthesurgical incisionis needed.Pyloromyotomyrequiresarightsupraumbilical inci-sion,withanalgesiclevelbeingrequiredforthisT4surgery.1
Wepresentanovelanesthetictechniqueinpatientswith HPSundergoingpyloromyotomy,basedontheperformance ofanultrasound-guidedthoracicparavertebralblock(PVB) andadministrationofasingledoseoflocalanestheticunder generalanesthesiaandtrachealintubation.
Thoracic paravertebral space is a wedge-shaped area containing the thoracic nerves and sympathetic trunk.8,9
The posterior wall is formed by the upper costotrans-verseligament,themedialwallbythevertebralbodyand the intervertebral disk, and the anterolateral wall of the parietal pleura that goes with the intercostal space.8 In
PVB, the anterior branch of the spinal nerve roots, gray and white communicans rami and sympathetic chain9 are
blocked.To minimizethe riskof vascular puncture,nerve injury,and pneumothorax,ultrasound-guided technique is recommended.8,9
PVBisassociatedwithlessurinaryretention7compared
toothertechniques,lowerincidenceofpostoperative nau-sea andvomiting, andless episodesof hypotensionand a reduction of pulmonary complications. Furthermore, the administration of local anesthetics in the paravertebral spaceproducesaunilateralsomaticandsympatheticblock that is advantageous for unilateral surgical procedures of chestandabdomen.
Ultrasound-guidedparavertebralblockforpyloromyotomyin3neonates 305
Willschkeetal.1describeanultrasound-guidedthoracic
epiduraltechniqueundersedationasanalternativeto gen-eralanesthesiaforpyloromyotomy.
Atpresent,evidencesupportsthatPVBisaseffectiveas theepiduralblockforpostoperativepainmanagement,and hasabettersafetyprofilethanneuroaxialtechniques.5
Somrietal.3 suggestedthatspinal anesthesiawith
iso-baricbupivacaineataconcentrationof0.5%andadoseof 0.8mg/kg−1wasanalternativetogeneralanesthesia;
how-everspinalblockforpyloromyotomycancauseuncontrolled highblockwithconsequentrespiratory1failureandtheneed
forurgentendotrachealintubation.3
Moyao-Garciaetal.4showacaseseriesofpyloromyotomy
withperformance ofcaudalblock with0.25% bupivacaine andavolumeof1.6mL/kg−1.Despitetheuseofhighdoses
of local anesthetic,the analgesic level required could be insufficient,withaT4---T61levelbeingnecessary.Thedose
oflocalanestheticsadministeredincaudalblocktoachieve an adequate metameric level of analgesia exceeds rec-ommended maximum doses5, allowing the occurrence of
cardiovascular4andneurologicalcomplications,whichcould
evenbemaskedinthisstudy,giventhedegreeofsedation used.
Ontheotherhand,thesympatheticblockassociatedwith bothspinalblockandthecaudalanesthesia,couldleadto hemodynamicrepercussionsinhypovolemicanddehydrated patientsduetotheunderlyingmedicalcondition.
In these 3 aforementioned studies, the authors use locoregional techniques combined withdeep sedation, so thatthepatientrespondedonlytostrongstimuli.
Our opinion is that endotracheal intubation is a safer technique in controlling airway in patients undergoing pyloromyotomy, since sedation levels used to maintain patient’s immobility, as well as the variability of the responsetosedationinneonates,bothwiththeuseof mida-zolam and propofol, could compromise the safety of the airway,leadingtolossofreflexeswiththeresultingriskof bronchopulmonaryaspirationinpatientsathighrisk.
Therefore,fromourexperience,weconductedan intra-venousinduction withnoadministrationof neuromuscular blockersnoropioids,decreasing theincidenceofepisodes ofapneainthepostoperativeperiodduetoresidual phar-macological effect. With the completion of PVB, optimal conditionsofanalgesiaandmusclerelaxationwereobtained to facilitate surgical access and adequate postoperative analgesia in the 12h of postoperative with no need for supplementaryanalgesics,aperiodthatcoincideswiththe highestincidenceofapneainthesepatients.
Insummary,theultrasound-guidedPVBwithsinglebolus oflocalanestheticassociatedwithgeneralanesthesiawith endotrachealintubationwassuccessfullyusedin3casesof infantswithpyloromyotomyduetoHPS,withnoepisodesof apneain thefollowing 24h of postoperative.We consider this technique an attractive alternative to the adminis-tration of intravenous opioids during general anesthesia, optimizing an adequate level of analgesia and reducing respiratorycomplicationsassociatedwiththeresidualeffect ofopioidsandthereforetheriskofcentralapneaand allow-ingearlyextubation.3
Ontheotherhand,comparedtootherlocoregional tech-niquesdescribed,fromourexperience,paravertebralblock reducestheriskofrespiratoryfailureassociatedwith epidu-ralblock,isassociatedwithfewercomplicationsand,unlike thecaudalblock,ensuresasufficientanalgesiclevelforthis surgicaltechnique.1,5,7
Conflicts
of
interests
Theauthorsdeclarenoconflictsofinterest.
References
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