Epidural versus non-epidural or no analgesia in labour

123 Pages·2012·1.22 MB·English

Epidural versus non-epidural or no analgesia in labour
(Review)
Anim-Somuah M, Smyth RMD, Jones L
ThisisareprintofaCochranereview,preparedandmaintainedbyTheCochraneCollaborationandpublishedinTheCochraneLibrary
2011,Issue12
http://www.thecochranelibrary.com
Epiduralversusnon-epiduralornoanalgesiainlabour(Review)
Copyright©2011TheCochraneCollaboration.PublishedbyJohnWiley&Sons,Ltd.
TABLE OF CONTENTS
HEADER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
ABSTRACT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
PLAINLANGUAGESUMMARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
BACKGROUND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
OBJECTIVES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
METHODS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
RESULTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Figure1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Figure2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
DISCUSSION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
AUTHORS’CONCLUSIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
ACKNOWLEDGEMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
CHARACTERISTICSOFSTUDIES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
DATAANDANALYSES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
Analysis1.1.Comparison1Epiduralversusnon-epiduralanalgesiainlabour,Outcome1Woman’sperceptionofpainrelief
inlabour. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
Analysis1.2.Comparison1Epiduralversusnon-epiduralanalgesiainlabour,Outcome2Instrumentaldelivery. . . 85
Analysis1.3.Comparison1Epiduralversusnon-epiduralanalgesiainlabour,Outcome3Caesareansection. . . . 86
Analysis1.4.Comparison1Epiduralversusnon-epiduralanalgesiainlabour,Outcome4Apgarscorelessthan7at5
minutes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
Analysis1.5.Comparison1Epiduralversusnon-epiduralanalgesiainlabour,Outcome5Maternalsatisfactionwithpain
reliefinlabour-proportionratingexcellentorverygood. . . . . . . . . . . . . . . . . . . . 89
Analysis1.6.Comparison1Epiduralversusnon-epiduralanalgesiainlabour,Outcome6Long-termbackache. . . 90
Analysis1.7.Comparison1Epiduralversusnon-epiduralanalgesiainlabour,Outcome7Lengthoffirststageoflabour
(minutes). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
Analysis1.8.Comparison1Epiduralversusnon-epiduralanalgesiainlabour,Outcome8Lengthofsecondstageoflabour
(minutes). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
Analysis1.9.Comparison1Epiduralversusnon-epiduralanalgesiainlabour,Outcome9Oxytocinaugmentation. . 93
Analysis1.10.Comparison1Epiduralversusnon-epiduralanalgesiainlabour,Outcome10Caesareansectionforfetal
distress. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
Analysis1.11. Comparison 1Epiduralversusnon-epidural analgesia inlabour,Outcome11Caesareansectionfor
dystocia. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
Analysis1.12.Comparison1Epiduralversusnon-epiduralanalgesiainlabour,Outcome12Timeofadministrationofpain
relieftotimepainreliefwassatisfactory. . . . . . . . . . . . . . . . . . . . . . . . . . 96
Analysis1.13.Comparison1Epiduralversusnon-epiduralanalgesiainlabour,Outcome13Woman’sperceptionofpain
reliefduringfirststageoflabour. . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
Analysis1.14.Comparison1Epiduralversusnon-epiduralanalgesiainlabour,Outcome14Woman’sperceptionofpain
reliefduringthesecondstageoflabour. . . . . . . . . . . . . . . . . . . . . . . . . . 97
Analysis1.15.Comparison1Epiduralversusnon-epiduralanalgesiainlabour,Outcome15Maternalsatisfactionwith
childbirthexperience. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
Analysis1.16.Comparison1Epiduralversusnon-epiduralanalgesiainlabour,Outcome16Perceivedfeelingofpoor
controlinlabour. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
Analysis1.17.Comparison1Epiduralversusnon-epiduralanalgesiainlabour,Outcome17Needforadditionalmeansof
painrelief. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
Analysis1.18.Comparison1Epiduralversusnon-epiduralanalgesiainlabour,Outcome18Maternalsatisfactionwithpain
reliefinlabour-continuousdata. . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
Analysis1.19.Comparison1Epiduralversusnon-epiduralanalgesiainlabour,Outcome19Maternalhypotensionas
definedbytrialauthors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
Analysis1.20.Comparison1Epiduralversusnon-epiduralanalgesiainlabour,Outcome20Postnataldepression(authors
definition,onmedication,orself-reported). . . . . . . . . . . . . . . . . . . . . . . . 101
Epiduralversusnon-epiduralornoanalgesiainlabour(Review) i
Copyright©2011TheCochraneCollaboration.PublishedbyJohnWiley&Sons,Ltd.
Analysis1.21.Comparison1Epiduralversusnon-epiduralanalgesiainlabour,Outcome21Motorblockade. . . . 101
Analysis1.22.Comparison1Epiduralversusnon-epiduralanalgesiainlabour,Outcome22Respiratory depression
requiringoxygenadministration. . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
Analysis1.23.Comparison1Epiduralversusnon-epiduralanalgesiainlabour,Outcome23Headache. . . . . . 102
Analysis1.24.Comparison1Epiduralversusnon-epiduralanalgesiainlabour,Outcome24Perinealtraumarequiring
suturing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
Analysis1.25.Comparison1Epiduralversusnon-epiduralanalgesiainlabour,Outcome25Nauseaandvomiting. . 103
Analysis1.26.Comparison1Epiduralversusnon-epiduralanalgesiainlabour,Outcome26Itch. . . . . . . . 104
Analysis1.27.Comparison1Epiduralversusnon-epiduralanalgesiainlabour,Outcome27Fever>38degreesC. . 105
Analysis1.28.Comparison1Epiduralversusnon-epiduralanalgesiainlabour,Outcome28Shivering. . . . . . 105
Analysis1.29.Comparison1Epiduralversusnon-epiduralanalgesiainlabour,Outcome29Drowsiness. . . . . 106
Analysis1.30.Comparison1Epiduralversusnon-epiduralanalgesiainlabour,Outcome30Urinaryretention. . . 107
Analysis1.31.Comparison1Epiduralversusnon-epiduralanalgesiainlabour,Outcome31Cathetherisationduring
labour. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
Analysis1.32.Comparison1Epiduralversusnon-epiduralanalgesiainlabour,Outcome32Malposition. . . . . 108
Analysis1.33.Comparison1Epiduralversusnon-epiduralanalgesiainlabour,Outcome33Surgicalamniotomy. . 108
Analysis1.34.Comparison1Epiduralversusnon-epiduralanalgesiainlabour,Outcome34Neonatalintensivecareunit
admission. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
Analysis1.35.Comparison1Epiduralversusnon-epiduralanalgesiainlabour,Outcome35Acidosisdefinedbycord
arterialpH<7.2atdelivery. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
Analysis1.36.Comparison1Epiduralversusnon-epiduralanalgesiainlabour,Outcome36Acidosisdefinedbycord
arterialpH<7.15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
Analysis1.37.Comparison1Epiduralversusnon-epiduralanalgesiainlabour,Outcome37Naloxoneadministration. 112
Analysis1.38.Comparison 1Epiduralversusnon-epidural analgesiainlabour,Outcome38Meconiumstaining of
liquor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
Analysis6.1.Comparison6Sensitivityanalysisofprimaryoutcomesbasedonexclusionofstudieswithhighorunclear
riskofbiasforallocationconcealment,Outcome1Maternalsatisfactionwithpainreliefinlabour-proportionrating
excellentorverygood. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114
Analysis6.2.Comparison6Sensitivityanalysisofprimaryoutcomesbasedonexclusionofstudieswithhighorunclearrisk
ofbiasforallocationconcealment,Outcome2Needforadditionalmeansofpainrelief. . . . . . . . . 115
Analysis7.1.Comparison7Sensitivityanalysisofprimaryoutcomesbasedonexclusionofstudieswithhighorunclearrisk
ofbiasforincompleteoutcomedata,Outcome1Maternalsatisfactionwithpainreliefinlabour-proportionrating
excellentorverygood. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
Analysis7.2.Comparison7Sensitivityanalysisofprimaryoutcomesbasedonexclusionofstudieswithhighorunclearrisk
ofbiasforincompleteoutcomedata,Outcome2Needforadditionalmeansofpainrelief. . . . . . . . 117
FEEDBACK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117
WHAT’SNEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
HISTORY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
CONTRIBUTIONSOFAUTHORS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
DECLARATIONSOFINTEREST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
SOURCESOFSUPPORT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
DIFFERENCESBETWEENPROTOCOLANDREVIEW . . . . . . . . . . . . . . . . . . . . . 120
INDEXTERMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
Epiduralversusnon-epiduralornoanalgesiainlabour(Review) ii
Copyright©2011TheCochraneCollaboration.PublishedbyJohnWiley&Sons,Ltd.
[InterventionReview]
Epidural versus non-epidural or no analgesia in labour
MillicentAnim-Somuah1,RebeccaMDSmyth2,LeanneJones3
1TamesideHospitalNHSFoundationTrust,Ashton-under-Lyne,UK.2SchoolofNursing,MidwiferyandSocialWork,TheUniversity
ofManchester,Manchester,UK.3CochranePregnancyandChildbirthGroup,DepartmentofWomen’sandChildren’sHealth,The
UniversityofLiverpool,Liverpool,UK
Contact address: Millicent Anim-Somuah, Tameside Hospital NHS Foundation Trust, Fountain Street, Ashton-under-Lyne, OL6
9RW,[email protected].
Editorialgroup:CochranePregnancyandChildbirthGroup.
Publicationstatusanddate:Newsearchforstudiesandcontentupdated(nochangetoconclusions),publishedinIssue12,2011.
Reviewcontentassessedasup-to-date: 30September2011.
Citation: Anim-Somuah M, SmythRMD, JonesL. Epidural versusnon-epidural or no analgesia in labour. CochraneDatabase of
SystematicReviews2011,Issue12.Art.No.:CD000331.DOI:10.1002/14651858.CD000331.pub3.
Copyright©2011TheCochraneCollaboration.PublishedbyJohnWiley&Sons,Ltd.
ABSTRACT
Background
Epiduralanalgesiaisacentralnerveblocktechniqueachievedbyinjectionofalocalanaestheticclosetothenervesthattransmitpain
andiswidelyusedasaformofpainreliefinlabour.However,thereareconcernsregardingunintendedadverseeffectsonthemother
andinfant.
Objectives
Toassesstheeffectsofallmodalitiesofepiduralanalgesia(includingcombined-spinal-epidural) onthemotherandthebaby,when
comparedwithnon-epiduralornopainreliefduringlabour.
Searchmethods
WesearchedtheCochranePregnancyandChildbirthGroup’sTrialsRegister(31March2011).
Selectioncriteria
Randomisedcontrolledtrialscomparingallmodalitiesofepiduralwithanyformofpainreliefnotinvolvingregionalblockade,orno
painreliefinlabour.
Datacollectionandanalysis
Twoofthereviewauthorsindependentlyassessedtrialsforeligibility,methodologicalqualityandextractedalldata.Weentereddata
intoRevMananddoublecheckeditforaccuracy.Primaryanalysiswasbyintentiontotreat;weconductedsubgroupandsensitivity
analyseswheresubstantialheterogeneitywasevident.
Mainresults
Weincluded38studiesinvolving9658women;allbutfivestudiescomparedepiduralanalgesiawithopiates.Epiduralanalgesiawas
foundtoofferbetterpainrelief(meandifference(MD)-3.36,95%confidenceinterval(CI)-5.41to-1.31,threetrials,1166women);
areductionintheneedforadditionalpainrelief(riskratio(RR)0.05,95%CI0.02to0.17,15trials,6019women);areducedrisk
ofacidosis(RR0.80,95%CI0.68to0.94,seventrials,3643women);andareducedriskofnaloxoneadministration(RR0.15,95%
CI0.10to0.23,10trials,2645women).However,epiduralanalgesiawasassociatedwithanincreasedriskofassistedvaginalbirth
(RR1.42,95%CI1.28to1.57,23trials,7935women),maternalhypotension(RR18.23,95%CI5.09to65.35,eighttrials,2789
Epiduralversusnon-epiduralornoanalgesiainlabour(Review) 1
Copyright©2011TheCochraneCollaboration.PublishedbyJohnWiley&Sons,Ltd.
women),motor-blockade(RR31.67,95%CI4.33to231.51,threetrials,322women),maternalfever(RR3.34,95%CI2.63to
4.23,sixtrials,2741women),urinaryretention(RR17.05,95%CI4.82to60.39,threetrials,283women),longersecondstageof
labour(MD13.66minutes,95%CI6.67to20.66,13trials,4233women),oxytocinadministration(RR1.19,95%CI1.03to1.39,
13trials,5815women)andanincreasedriskofcaesareansectionforfetaldistress(RR1.43,95%CI1.03to1.97,11trials,4816
women).Therewasnoevidenceofasignificantdifferenceintheriskofcaesareansectionoverall(RR1.10,95%CI0.97to1.25,27
trials,8417women),long-termbackache(RR0.96,95%CI0.86to1.07,threetrials,1806women),Apgarscorelessthansevenatfive
minutes(RR0.80,95%CI0.54to1.20,18trials,6898women),andmaternalsatisfactionwithpainrelief(RR1.31,95%CI0.84
to2.05,seventrials,2929women).Wefoundsubstantialheterogeneityforthefollowingoutcomes:painrelief;maternalsatisfaction;
needforadditional meansofpainrelief;lengthofsecondstageoflabour;andoxytocinaugmentation. Thiscouldnotbeexplained
bysubgrouporsensitivityanalyses,wheredataallowedanalysis.Nostudiesreportedonrarebutpotentiallyseriousadverseeffectsof
epiduralanalgesia.
Authors’conclusions
Epidural analgesia appearstobeeffectiveinreducing painduring labour.However,women whouse thisformof painreliefare at
increased risk of having an instrumental delivery.Epidural analgesia hadno statistically significant impact on therisk of caesarean
section, maternalsatisfaction withpainreliefandlong-termbackache anddidnotappear tohaveanimmediateeffectonneonatal
statusasdeterminedbyApgarscores.Furtherresearchmaybehelpfultoevaluaterarebutpotentiallysevereadverseeffectsofepidural
analgesiaonwomeninlabourandlong-termneonataloutcomes.
PLAIN LANGUAGE SUMMARY
Epiduralsforpainreliefinlabour
Painreliefisimportantforwomeninlabour.Pharmacological methodsofpainreliefinclude inhalationofnitrousoxide, injection
ofopioids andregional analgesiawithanepiduralforacentralnerveblock.Epiduralsarewidelyusedforpainreliefinlabour and
involveaninjectionofalocalanaestheticintothelowerregionofthespineclosetothenervesthattransmitpain.Epiduralsolutionsare
givenbybolusinjection,continuousinfusionorusingapatient-controlledpump.Lowerconcentrationsoflocalanaestheticareneeded
whentheyaregiventogetherwithanopiate,allowingwomentomaintaintheabilitytomovearoundduringlabourandtobeardown.
Epiduralanalgesiamaysometimesgiveinadequateanalgesia,whichmaybeduetonon-uniformspreadoflocalanaesthetic.Combined
spinal-epiduralinvolvesasingleinjectionoflocalanaestheticoropiateintothecerebralspinalfluidforfastonsetofpainreliefaswell
asinsertionoftheepiduralcatheterforcontinuingpainrelief.Sideeffectssuchasitchiness,drowsiness,shiveringandfeverhavebeen
reportedandrarebutpotentiallysevereadverseeffectsofepiduralanalgesiadooccur.
Thereviewidentified38randomisedcontrolledstudiesinvolving9658women.Allbutfivestudiescomparedepiduralanalgesiawith
opiates.Epiduralsrelievedlabourpainbetterthanothertypesofpainmedicationbutledtomoreuseofinstrumentstoassistwith
thebirth.Caesareandeliveryratesdidnotdifferoverallandnorwerethereeffectsoftheepiduralonthebabysoonafterbirth;fewer
babies neededadrug(naloxone)tocounter opiate usebythemotherforpainrelief.Theriskof caesareansectionforfetaldistress
wasincreased.Womenwhousedepiduralsweremorelikelytohavealongerdelivery(secondstageoflabour),neededtheirlabour
contractionsstimulatedwithoxytocin,experiencedverylowbloodpressure,wereunabletomoveforaperiodoftimeafterthebirth
(motor blockage), had problems passing urine (fluid retention) and suffered fever. Long-term backache was no different. Further
researchonreducingtheadverseoutcomeswithepiduralswouldbehelpful.
BACKGROUND
(Neilson2011),andshareagenericprotocol(Jones2011).
ThisreviewisoneinaseriesofCochranereviewsexaminingpain
managementinlabour.Thesereviewscontributetoanoverview Painreliefisanimportantissueforwomeninlabour.Thelevelof
ofsystematicreviewsofpainmanagementforwomeninlabour painexperiencedandtheeffectivenessofpainreliefmayinfluence
Epiduralversusnon-epiduralornoanalgesiainlabour(Review) 2
Copyright©2011TheCochraneCollaboration.PublishedbyJohnWiley&Sons,Ltd.
a woman’s satisfaction with labour and delivery and may have ingofpainfulimpulsesfromthenervesastheycrosstheepidu-
immediate and long-term emotional and psychological effects( ralspaceresultsinanalgesiawhichshouldbeapparentwithin10
Christiansen 2002).The type of pain reliefused in labour may to 20 minutes of administration. The anaesthetic placed in the
impact on breastfeeding and mother-infant interaction (Walker epiduralspaceexertsaconcentration specificeffect,affectingall
1997). themodalitiesofsensation oftheblockednervestovaryingde-
grees, such thatadministration of alower-dose anaesthetic(e.g.
Womenexperiencevaryingdegreesofpaininlabourandexhibit
0.125% bupivacaine) partially selectively blocks painful stimuli
anequallyvaryingrangeofresponsestoit.Anindividual’sreaction
whilepreservingmotorfunction,whereashigherdosesofanaes-
tothepainoflabourmaybeinfluencedbythecircumstancesof
theticaffordcompletesensoryandmotorblockadelimitingmo-
herlabour,theenvironment,herculturalbackground,preparation
bilityinlabour.Blockingofsympatheticnervesoccursatvarying
towardsherlabourandthesupportavailabletoher(Brownridge
concentrationsandmanifestsasvasodilatationandhypotension.
1991; McCrea 2000; Rowlands 1998). Need for pain relief in
labourisalsoinfluencedbythetypeofonsetoflabour (sponta- Epiduralanalgesiaisconsideredtobeeffectiveforreducingpainin
neousorinduced)andmedicalinterventionssuchasinstrumental labour(Brownridge1991;Howell2001).Thechoiceofdrugsand
vaginaldeliveryandepisiotomy.Severalmethodsofrelievingpain
dosagevariesfrominstitutiontoinstitution.Protocolsregarding
inlabourandvariouscopingstrategieshavebeenadvocated,rang-
thecareofwomenusingepiduralanalgesiaalsovaryamonghos-
ingfromlimitedinterventionsuchasbreathingexercisestomed-
pitals.Epiduralsolutionsareadministeredeitherbybolus,contin-
icaltechniqueslikeepiduralanalgesia.Regardlessoftheintensity
uousinfusionorpatient-controlledpump.Anintermittenttech-
of the pain experiencedand response generated, itis important
nique involvesinjections of local anaestheticthrough acatheter
thatwhatevermethodisusedtoamelioratematernaldiscomfort,
positionedintheepiduralspace.Bolusesofhigherconcentrations,
itisbotheffectiveandsafeforthemotherandbaby.
as used in the earlier years, have been associated with a dense
Relaxationtherapies,distractiontechniquesandcontinuoussup- motorblockresultinginreducedmobility,decreasedpelvictone
portare believedtohelpwomen in labour to use their own re- and impairment of the bearing down effortin thesecond stage
sourcestocopewithpain.Othernon-pharmacological methods oflabour(Thornton2001).Morerecentlytherehasbeenatrend
usedforrelievingpainincludeacupressure, acupuncture, reflex- tousealowerconcentrationoflocalanaestheticincombination
withavarietyofopiates;thesecombinationsprovideanalgesicef-
ology,aromatherapy,transcutaneous electricalnervestimulation
andintradermalinjectionofsterilewater(Martensson1999).Re- fectwhileallowingthewomantomaintainsomemotorfunction,
portedeffectivenessofthesemethodsvary(Dowswell2009;Ranta suchastheabilitytomoveduringherlabourandretainherability
1994;Smith2011a;Smith2011b).Therearedatatoshowthat tobeardown(COMET2001;Russell2000).Combinedspinal-
womenwhohavecontinuousintrapartumsupportarelesslikely epidural(CSE)involvesasingleinjectionoflocalanaestheticand/
tohavepainreliefinlabour(Hodnett2011)andmeasures,such oropiateintothecerebralspinalfluidaswellasinsertionofthe
epiduralcatheter.CSEcombinestheadvantagesofspinalanalge-
aslabouringinwater,massage,acupunctureandhypnosismaybe
sia (faster onset of pain relief, more reliable analgesia) with the
helpfultherapiesfor pain management inlabour (Chang 2002;
Cluett2009;Cyna2004).Efficacyofothermethodssuchasau- advantages of epidural analgesia such as continuing pain relief,
dioanalgesia and music therapy remains to be assessed (Cluett potentiallymaintainedthroughouttheentiredurationoflabour
2009).Pharmacologicalmethodslikeinhalationofnitrousoxide, (Hughes2003).Epiduralanalgesiaallowsthewomantoremain
parenteralinjectionofopioidsandregionalanalgesiaintheform alertduringlabour.Theregionaladministrationofepiduraldrugs
mayhelpavoidsomesystemicsideeffectsofanalgesicmedication
ofepiduralandcombinedspinalepiduralarealsocommonlyused
torelievepaininlabour. onthebaby,suchasopioid-inducedneonatalrespiratorydepres-
sion.Afunctioningepiduralallowstheoptionofregionalanaes-
Epiduralanalgesiawasfirstusedinobstetricpracticein1946and thesia for interventions such as caesarean section or manual re-
itsuseinlabourhassteadilyincreaseduntilthelastdecade(DOH movalofretainedplacenta,therebyavoidingtherisksassociated
2005).Approximately20% ofwomenintheUK(DOH2005; withgeneralanaesthesia(Hibbard1996).However,spinalanaes-
Khor2000)and58%ofwomenintheUSA(Declercq2002)use thesiacanalsobeusedforthispurpose.
thisformofpainrelief.However,thereisconsiderablevariation
intheavailabilityanduseofepiduralanalgesiabetweenhospitals Although epidural analgesia may provide effectivepain reliefin
in the same country (DOH 2005). Epidural analgesia is a cen- labour,itmaysometimesgiveinadequateanalgesiawhichmaybe
tralnerveblockade technique,which involvestheinjectionof a duetonon-uniformspreadoflocalanaesthetic.Reportedmater-
local anaesthetic into the lower region of the spine close to the nalcomplicationsincludehypotension-areductioninmaternal
nervesthattransmitpainfulstimulifromthecontracting uterus bloodpressure(BP).Severesuddenhypotension(morethan20%
and birth canal. The anaesthetic inhibits nerve conduction by decreaseinbaselineBP)mayresultinaclinicallysignificantde-
blockingsodiumchannelsinnervemembranes,therebyprevent- creaseinutero-placentalbloodflow,whichcouldpotentiallyaffect
ingthepropagationofnerveimpulsesalongthesefibres.Block- deliveryofoxygentothebaby.Thismayespeciallycompromise
Epiduralversusnon-epiduralornoanalgesiainlabour(Review) 3
Copyright©2011TheCochraneCollaboration.PublishedbyJohnWiley&Sons,Ltd.
ababywithinadequatereserves(Vincent1998).Forthisreason WeincludedabstractsofunpublishedmanuscriptsofRCTs,and
intravenousfluidsmaybegivenbeforeadministeringtheepidu- excludedquasi-randomisedtrials.
raldrugs(fluidpreload)toattenuatethedecreaseinmaternalBP.
Sideeffectssuchasitchiness,drowsiness,shiveringandfeverhave
alsobeenreported(Buggy1995;Eberle1996).Womenmayde- Typesofparticipants
velopurinaryretentionwhileusingepiduralanalgesia.Thismay Pregnant women requesting pain relief in labour, regardless of
necessitate theinsertion of acatheter todrain the bladder. Uri- parityandwhetherlabourwasspontaneousorinduced.
nary retention in the postpartum period has been attributed to
longlaboursinwomenusingepiduralanalgesia(Liang2002).Less
commonsideeffectsreportedareaccidentalpunctureofthedura, Typesofinterventions
whichcansometimescausesevereheadache-post-duralpuncture We considered all forms of epidural administration, compared
headache(1%)(Stride1993).Thisresolvesspontaneouslyinsome withanyformofpainreliefnotinvolving regional blockade,or
women;however,abloodpatchmaybeneededwhentheheadache nopainrelief.Trialscomparing differenttechniquesof epidural
ispersistent.Thisinvolvesasterileinjectionof15mlto20mlof arethesubjectofanotherreview(Hughes2003).
thewoman’sfreshbloodintotheepiduralspace(Bromage1999;
ThisreviewisoneinaseriesofCochranereviewsexaminingpain
Vincent1998).Thisresolvestheheadachefor60%ofwomen.
managementinlabour.Thesereviewscontributetoanoverviewof
systematicreviewsofinterventionsforpainmanagementinlabour,
Epiduralanalgesiamayinfluencethecourseoflabour.Therehave
andshareagenericprotocol.Toavoidduplication,thedifferent
beensuggested associations with malpositions of thefetalhead,
methodsofpainmanagementhavebeenlistedinaspecificorder,
prolongedlabour,increaseduseofoxytocinandofinstrumental
fromoneto15. Individual reviewsfocusingonparticularinter-
deliveries(Eberle1996);possibleeffectsontheriskofcaesarean
ventionsincludecomparisonswithonlytheinterventionaboveit
sectioncontinuetobedebated(Lieberman2002).Effectsofepidu-
onthelist.Methodsofpainmanagementidentifiedinthefuture
ralanalgesiaontheneonatemaybemixed.HighercordpHvalues
willbeaddedtotheendofthelist.Thecurrentlistisasfollows.
andlessnaloxoneuseatbirthhavebeenreported(Halpern1998),
1. Placebo/notreatment
ashasagreaterneedforneonatalresuscitation(COMET2001).
2. Hypnosis(Madden2011)
Ithasbeensuggestedthatbabiesofwomenwhouseepiduralanal-
3. Biofeedback(Barragán2011)
gesiamaybemorepronetolowbloodsugarinthefirsthoursafter
4. Intracutaneousorsubcutaneoussterilewaterinjection
birth(Swanstrom1981b).
(Derry2011)
The aim of this review is to assess the effectivenessof analgesia 5. Immersioninwater(Cluett2009)
andbenefitsaffordedbyepidural,andtheriskofpotentialadverse 6. Aromatherapy(Smith2011a)
effects when compared with non-epidural methods of relieving 7. Relaxationtechniques(yoga,music,audio)
paininlabourornopainrelief. 8. Acupunctureoracupressure(Smith2011b)
9. Manualmethods(massage,reflexology)(Smith2011c)
10. Transcutaneouselectricalnervestimulation(TENS)
OBJECTIVES (Dowswell2009)
11. Inhaledanalgesia(Klomp2011)
Toassesstheeffectsandsafetyofallmodalitiesofepiduralanal- 12. Opioids(Ullman2010)
gesia(includingcombined-spinalepidural),duringlabouronthe 13. Non-opioiddrugs(Othman2011)
womanandthebaby,whencomparedwithotherformsofpain 14. Localanaestheticnerveblocks(Novikova2011)
reliefornopainrelief. 15. Epidural(includingcombinedspinalepidural)(Simmons
2007)
Accordingly, this review includes comparisons of any form of
METHODS epiduraladministration,comparedwith:1.placebo/notreatment;
2. hypnosis; 3. biofeedback; 4. intracutaneous or subcutaneous
sterilewaterinjection;5.immersioninwater;6.aromatherapy;7.
relaxationtechniques(yoga,music,audio);8.acupunctureoracu-
Criteriaforconsideringstudiesforthisreview
pressure; 9. manual methods(massage, reflexology);10. TENS;
11.inhaledanalgesia;12.opioids;13.non-opioiddrugs;and14.
localanaestheticnerveblocks.
Typesofstudies
Randomisedcontrolledtrials(RCTs)comparingepiduralanalge-
Typesofoutcomemeasures
siawithalternativeformsofpainreliefornopainreliefinlabour.
Epiduralversusnon-epiduralornoanalgesiainlabour(Review) 4
Copyright©2011TheCochraneCollaboration.PublishedbyJohnWiley&Sons,Ltd.
Primaryoutcomes Otheroutcomes
Cost(asdefinedbytrialists)
Effectsofinterventions
Painintensity(asdefinedbytrialists) Secondaryoutcomes
Satisfactionwithpainrelief(asdefinedbytrialists)
Lengthoffirststageoflabour
Senseofcontrolinlabour(asdefinedbytrialists)
Lengthofsecondstageoflabour
Satisfactionwithchildbirthexperience(asdefinedbytrialists)
Oxytocinaugmentation
Needforothermeansofpainrelief
Caesareansectionforfetaldistress
Caesareansectionfordystocia
Safetyofinterventions
Effect(negative)onmother/babyinteraction
Searchmethodsforidentificationofstudies
Breastfeeding(atspecifiedtimepoints)
Assistedvaginalbirth
Caesareansection
Sideeffects(formother) Electronicsearches
• Long-termbackache(asdefinedbytrialauthors) WesearchedtheCochranePregnancyandChildbirthGroupTrials
• Maternalhypotension(asdefinedbyauthors) RegisterbycontactingtheTrialsSearchCo-ordinator(31March
• Postnataldepression(authors’definition,treatmentfor 2011).
depressionorselfreported) TheCochranePregnancyandChildbirthGroup’sTrialsRegister
• Motorblockade ismaintainedbytheTrialsSearchCo-ordinatorandcontainstrials
• Respiratorydepressionrequiringoxygenadministration identifiedfrom:
• Uterinerupture 1. quarterlysearchesoftheCochraneCentralRegisterof
• Headache ControlledTrials(CENTRAL);
• Headacherequiringbloodpatch 2. weeklysearchesofMEDLINE;
• Venousthromboembolicevents 3. weeklysearchesofEMBASE;
• Perinealtraumarequiringsuturing 4. handsearchesof30journalsandtheproceedingsofmajor
• Nauseaand/orvomiting conferences;
• Itching 5. weeklycurrentawarenessalertsforafurther44journals
• Fever plusmonthlyBioMedCentralemailalerts.
• Shivers DetailsofthesearchstrategiesforCENTRAL, MEDLINE and
• Drowsiness EMBASE,thelistofhandsearchedjournalsandconferencepro-
• Urinaryretention ceedings,andthelistofjournalsreviewedviathecurrentaware-
• Catheterisationduringlabour ness service can be found in the ‘Specialized Register’ section
• Othermorbidity(e.g.impairedconsciousness,meningitis, withintheeditorialinformationabouttheCochranePregnancy
intensivecareunitadmission,paralysis) andChildbirthGroup.
• Malposition(asdefinedbytrialauthors) Trialsidentifiedthroughthesearchingactivitiesdescribedabove
• Surgicalamniotomy areeachassignedtoareviewtopic(ortopics).TheTrialsSearch
Sideeffects(forbaby) Co-ordinatorsearchestheRegisterforeachreviewusingthetopic
• AcidosisasdefinedbycordbloodarterialpHlessthan7.2 listratherthankeywords.
• AcidosisasdefinedbycordbloodarterialpHlessthan7.15 Wedidnotapplyanylanguagerestrictions.
• Naloxoneadministration
• Neonatalhypoglycaemia(lessthanorequalto1.67mmol/l)
• Birthtrauma Datacollectionandanalysis
• Long-termneonatalcomplication
Weusedthefollowingmethodswhenassessinganyreportsiden-
• Meconiumstainingofliquor
tifiedbythesearch.
Admissiontospecialcarebabyunit/neonatal intensive careunit
(asdefinedbytrialists)
Selectionofstudies
Apgarscorelessthansevenatfiveminutes
Poorinfantoutcomesatlong-termfollow-up(asdefinedbytrialists Threereviewauthors(MillicentAnim-Somuah(MA),RSmyth
-e.g.seizures,disabilityinchildhood) (RS), L Jones (LJ)) independently assessed for inclusion all the
Epiduralversusnon-epiduralornoanalgesiainlabour(Review) 5
Copyright©2011TheCochraneCollaboration.PublishedbyJohnWiley&Sons,Ltd.
potentialstudiesweidentifiedasaresultofthesearchstrategy.We (3.1)Blindingofparticipantsandpersonnel(checkingfor
resolvedanydisagreementthroughdiscussion. possibleperformancebias)
Wedescribedforeachincludedstudythemethodsused,ifany,to
blindstudyparticipantsandpersonnelfromknowledgeofwhich
interventionaparticipantreceived.Weconsideredthatstudiesare
Dataextractionandmanagement
atlowriskofbiasiftheywereblinded,orifjudgedthatthelackof
We designed a form to extract data. For eligible studies, three blindingwouldbeunlikelytoaffectresults.Weassessedblinding
reviewauthors(MA,RS,LJ)extractedthedatausingtheagreed separatelyfordifferentoutcomesorclassesofoutcomes.
form.Weresolveddiscrepanciesthroughdiscussion.Weentered Weassessedthemethodsas:
dataintoReviewManagersoftware(RevMan2011)andchecked • low,highorunclearriskofbiasforparticipants;
foraccuracy. • low,highorunclearriskofbiasforpersonnel.
When information regarding any of the above was unclear, we
attempted to contact authors of the original reports to provide
(3.2)Blindingofoutcomeassessment(checkingforpossible
furtherdetails.
detectionbias)
Wedescribedforeachincludedstudythemethodsused,ifany,to
blindoutcomeassessorsfromknowledgeofwhichinterventiona
Assessmentofriskofbiasinincludedstudies participantreceived. Weassessedblindingseparatelyfordifferent
outcomesorclassesofoutcomes.
Two review authors independently assessedrisk of bias foreach
Weassessedmethodsusedtoblindoutcomeassessmentas:
study using the criteria outlined in the Cochrane Handbook for
• low,highorunclearriskofbias.
Systematic Reviews of Interventions (Higgins 2011). We resolved
any disagreement by discussion or by involving a third assessor
(LJ).
(4)Incompleteoutcomedata(checkingforpossibleattrition
biasduetotheamount,natureandhandlingofincomplete
outcomedata)
(1)Randomsequencegeneration(checkingforpossible Wedescribedforeachincludedstudy, andfor eachoutcome or
selectionbias) classofoutcomes,thecompletenessofdataincludingattritionand
exclusionsfromtheanalysis.Westatedwhetherattritionandex-
Wedescribedforeachincludedstudythemethodusedtogenerate
clusionswerereportedandthenumbersincludedintheanalysisat
theallocationsequenceinsufficientdetailtoallowanassessment
eachstage(comparedwiththetotalrandomisedparticipants),rea-
ofwhetheritshouldproducecomparablegroups.
sonsforattritionorexclusionwherereported,andwhethermiss-
Weassessedthemethodas:
ingdatawerebalancedacrossgroupsorwererelatedtooutcomes.
• lowriskofbias(anytrulyrandomprocess,e.g.random
Wheresufficientinformation isreported,orcanbe suppliedby
numbertable;computerrandomnumbergenerator);
thetrialauthors,wewillre-includemissing dataintheanalyses
• highriskofbias(anynon-randomprocess,e.g.oddoreven
whichweundertake.
dateofbirth;hospitalorclinicrecordnumber);or
Weassessedmethodsas:
• unclearriskofbias. • lowriskofbias(e.g.nomissingoutcomedata;missing
outcomedatabalancedacrossgroups,lessthan20%loss);
• highriskofbias(e.g.numbersorreasonsformissingdata
imbalancedacrossgroups;‘astreated”analysisdonewith
(2)Allocationconcealment(checkingforpossibleselection
substantialdepartureofinterventionreceivedfromthatassigned
bias)
atrandomisation);
We described for each included study the methodused tocon- • unclearriskofbias.
cealallocationtointerventionspriortoassignmentandassessed
whetherintervention allocationcouldhavebeenforeseeninad-
vanceof,orduringrecruitment,orchangedafterassignment. (5)Selectivereporting(checkingforreportingbias)
Weassessedthemethodsas: We described for each included study how we investigated the
• lowriskofbias(e.g.telephoneorcentralrandomisation; possibilityofselectiveoutcomereportingbiasandwhatwefound.
consecutivelynumberedsealedopaqueenvelopes); Weassessedthemethodsas:
• highriskofbias(openrandomallocation;unsealedornon- • lowriskofbias(whereitisclearthatallofthestudy’spre-
opaqueenvelopes,alternation;dateofbirth); specifiedoutcomesandallexpectedoutcomesofinteresttothe
• unclearriskofbias. reviewhavebeenreported);
Epiduralversusnon-epiduralornoanalgesiainlabour(Review) 6
Copyright©2011TheCochraneCollaboration.PublishedbyJohnWiley&Sons,Ltd.
• highriskofbias(wherenotallthestudy’spre-specified Unitofanalysisissues
outcomeshavebeenreported;oneormorereportedprimary
outcomeswerenotpre-specified;outcomesofinterestare
reportedincompletelyandsocannotbeused;studyfailsto Cluster-randomisedtrials
includeresultsofakeyoutcomethatwouldhavebeenexpected
Wewouldincludecluster-randomisedtrialsintheanalysesalong
tohavebeenreported);
withindividuallyrandomisedtrials,andadjusttheirsamplesizes
• unclearriskofbias.
orstandarderrorsusingthemethodsdescribedintheHandbook
usinganestimateoftheintra-clustercorrelationco-efficient(ICC)
derivedfromthetrial(ifpossible),fromasimilartrialorfroma
(6)Otherbias(checkingforbiasduetoproblemsnot
studyofasimilarpopulation.IfweusedICCsfromothersources,
coveredby(1)to(5)above)
wewouldreportthisandconductsensitivityanalysestoinvestigate
Wedescribedforeachincludedstudyanyimportantconcernswe
theeffectofvariation intheICC.Ifweidentifiedboth cluster-
hadaboutotherpossiblesourcesofbias.
randomisedtrialsandindividually-randomisedtrials,weplanned
Weassessedwhethereachstudywasfreeofotherproblemsthat
tosynthesisetherelevantinformation.Weconsidereditreasonable
couldputitatriskofbias:
tocombinetheresultsfrombothiftherewaslittleheterogeneity
• lowriskofotherbias;
betweenthestudydesignsandtheinteractionbetweentheeffectof
• highriskofotherbias;
interventionandthechoiceofrandomisationunitwasconsidered
• unclearwhetherthereisriskofotherbias.
tobeunlikely.
Wewouldalsoacknowledgeheterogeneityintherandomisation
(7)Overallriskofbias unitandperformasensitivityanalysistoinvestigatetheeffectsof
therandomisationunit.
Wemadeexplicitjudgementsaboutwhetherstudieswereathigh
risk of bias, according to the criteria given in the Handbook (
Higgins 2011). With reference to (1) to (6) above, we assessed
Dealingwithmissingdata
the likely magnitude and direction of the bias and whether we
Forincludedstudies,wenotedlevelsofattrition.Weexploredthe
considereditlikelytoimpactonthefindings. Weexploredthe
impactofincludingstudieswithhighlevelsofmissingdatainthe
impactofthelevelofbiasthroughundertakingsensitivityanalyses
overallassessmentoftreatmenteffectbyusingsensitivityanalysis.
-seeSensitivityanalysis.
For all outcomes, we carried out analyses, as far as possible, on
an intention-to-treat basis, i.e. we attempted toinclude all par-
Measuresoftreatmenteffect ticipantsrandomised toeachgroupintheanalyses, andallpar-
ticipantsanalysedinthegrouptowhichtheywereallocated,re-
gardlessofwhetherornottheyreceivedtheallocatedintervention.
Dichotomousdata Thedenominatorforeachoutcomeineachtrialwasthenumber
Fordichotomousdata,wepresentedresultsassummaryriskratio randomised minus any participants whose outcomes are known
with95%confidenceintervals. tobemissing.
Continuousdata Assessmentofheterogeneity
For continuous data, we used the mean difference if outcomes We assessedstatistical heterogeneityineachmeta-analysis using
weremeasuredinthesamewaybetweentrials.Weusedthestan- theT²,I²andChi²statistics.Weregardedheterogeneityassub-
dardisedmeandifferencetocombinetrialsthatmeasuredthesame stantialifT²wasgreaterthanzeroandeitherI²wasgreaterthan
outcome,butusedifferentmethods. 30%ortherewasalowPvalue(lessthan0.10)intheChi²test
forheterogeneity.
Ordinaldata
Forordinaldatameasuredonscales(e.g.painmeasuredonvisual Assessmentofreportingbiases
analogue scales) we analysed as continuous data and the inter- Iftherewere10ormorestudiesinthemeta-analysisweplannedto
ventioneffectwasexpressedasadifferenceinmeans.Forordinal investigatereportingbiases(suchaspublicationbias)usingfunnel
data (e.g.satisfactionwithpainrelief)measuredonshorterordi- plots.Wewouldassessfunnelplotasymmetryvisually,andwould
nalscalese.g.(excellent,verygood,good)weanalysedasdichoto- useformaltestsforfunnelplotasymmetry.Forcontinuous out-
mousdatabycombiningcategories(e.g.excellentandverygood) comeswewouldusethetestproposedbyEgger1997,andfordi-
andtheinterventioneffectwasexpressedusingriskratios. chotomousoutcomeswewouldusethetestproposedbyHarbord
Epiduralversusnon-epiduralornoanalgesiainlabour(Review) 7
Copyright©2011TheCochraneCollaboration.PublishedbyJohnWiley&Sons,Ltd.