REVISTA
BRASILEIRA
DE
ANESTESIOLOGIA
OfficialPublicationoftheBrazilianSocietyofAnesthesiologywww.sba.com.br
SCIENTIFIC
ARTICLE
Administration
of
paracetamol
versus
dipyrone
by
intravenous
patient-controlled
analgesia
for
postoperative
pain
relief
in
children
after
tonsillectomy
夽
Mesut
Sener
a,∗,
Aysu
Kocum
a,
Esra
Caliskan
a,
Ismail
Yilmaz
b,
Fatma
Caylakli
b,
Anis
Aribogan
aaDepartmentofAnaesthesiologyandReanimation,BaskentUniversityFacultyofMedicine,Ankara,Turkey
bDepartmentofOtorhinolaryngology,BaskentUniversityFacultyofMedicine,Ankara,Turkey
Received8August2013;accepted23September2013 Availableonline29October2013
KEYWORDS
Analgesia;
Patient-controlled; Pediatric;
Pain;
Postoperative; Tonsillectomy
Abstract
Backgroundandobjective: Wecomparedtheefficacyofintravenous(IV)paracetamol versus
dipyroneviapatient-controlledanalgesia(PCA)forpostoperativepainreliefinchildren.
Methods:Thestudywascomposedof120childrenwhohadundergoneelectivetonsillectomy
afterreceivinggeneralanesthesia.Patientsweredividedinto3groupsaccordingtothedosage
ofpostoperativeintravenous-patient-controlledanalgesia:paracetamol,dipyrone,orplacebo.
Painwasevaluatedusinga0-to100-mmvisualanalogscaleand1- to4-painreliefscoreat
30min, 1, 2, 4, 6, 12, and 24h postoperatively. Pethidine(0.25mgkg−1)was administered
intravenously topatients requiring rescueanalgesia. Pethidinerequirementswere recorded
duringthefirst24hpostoperatively,andtreatmentrelatedadverseeffectswerenoted.
Results:Postoperativevisual analog scale scores were significantlylower with paracetamol
groupcomparedwithplacebogroupat6h(p<0.05),dipyronegroupcomparedwithplacebo
groupat30minand6h(p<0.05).Nosignificantdifferencesregardingvisualanalogscalevalues
at1,2,4,12,and24hwerefound.Nosignificantdifferenceswerefoundbetweengroupswith
respecttopainreliefscore(p>0.05).Postoperativepethidinerequirementsweresignificantly
lowerwithparacetamolanddipyronegroupscompared withplacebogroup(62.5%,68.4% vs
90%,p<0.05).Nosignificantdifferenceswerefoundbetweengroupswithrespecttonausea,
vomitingandtheanyotheradverseeffectsofthedrugs(p>0.05).
Conclusions:Paracetamolanddipyronehavewelltolerability profileandeffective analgesic
propertieswhenadministeredIV-PCAforpostoperativeanalgesiainchildrenaftertonsillectomy.
©2013SociedadeBrasileiradeAnestesiologia.PublishedbyElsevier EditoraLtda.Allrights
reserved.
夽
Thispaperwaspresentedasaposteratthe45thCongressoftheTurkishAnesthesiologyandIntensiveCareSocietyonOctober26---30, 2011,Antalya,Turkey.Thepresentationalsoreportedinthepress‘‘TurkAnestReanDerDergisi2011;39(Suppl.1):p.106’’.
∗Correspondingauthor.
E-mail:[email protected](M.Sener).
PALAVRAS-CHAVE
Analgesia;
Controladapelo
paciente; Pediatria; Dor;
Pós-operatório; Tonsilectomia
Administrac¸ãodeparacetamolversusdipironaemanalgesiacontroladapelopaciente
porviaintravenosaparaalíviodadornopós-operatóriodecrianc¸asapós
tonsilectomia
Resumo
Justificativaeobjetivo: Comparamos a eficácia da administrac¸ão de paracetamol versus
dipironaemanalgesiacontroladapelopaciente(PCA)porviaintravenosa(IV)paraalívioda
dornoperíodopós-operatórioemcrianc¸as.
Métodos: Oestudofoi compostopor120crianc¸assubmetidasàtonsilectomia sobanestesia
geral.OspacientesforamdivididosemtrêsgruposdeacordocomadoseIVdeanalgesia
con-troladapelopacientenopós-operatório:paracetamol,dipironaouplacebo.Adorfoiavaliada
usandoumaescalavisualanalógicade0-100mmeescorede1-4paraalíviodadornostempos
de30minutos,1,2,4,6,12e24horasdepós-operatório.Petidina(0,25mgkg−1)foi
admin-istradaIVaospacientesqueprecisaramdeanalgesiaderesgate.Anecessidadedepetidinafoi
registradaduranteasprimeiras24hdepós-operatório,eosefeitosadversosrelacionadosao
tratamentoforamregistrados.
Resultados: Osescoresdaescalavisualanalógicanopós-operatórioforamsignificativamente
menoresnogrupoparacetamolemcomparac¸ãocomogrupoplaceboem6h(p<0,05),nogrupo
dipironaemcomparac¸ãocomogrupoplaceboem30mine6h(p<0,05).Nãohouvediferenc¸a
significativaemrelac¸ãoaosvaloresdaescalavisualanalógicanostemposavaliadosde1,2,4,
12e24horas.Nãohouvediferenc¸asignificativaentreosgruposquantoaoescoredealívioda
dor(p>0,05).Anecessidadedepetidinafoisignificativamentemenornosgruposparacetamol
edipironaemcomparac¸ãocomogrupoplacebo(62,5%,68,4%vs.90%,p<0,05).Nãohouve
diferenc¸a significativaentreos grupos em relac¸ão àincidênciade náusea, vômitoe outros
efeitosadversosdosmedicamentos(p>0,05).
Conclusões: Paracetamoledipironapossuemum perfildeboatolerabilidadeepropriedades
analgésicas eficazes quandoadministrados IV para ACP no pós-operatório de crianc¸as após
tonsilectomia.
©2013SociedadeBrasileira deAnestesiologia.PublicadoporElsevierEditoraLtda.Todosos
direitosreservados.
Introduction
Tonsillectomy can be considered as the most widely
practicedoneamongthechildhoodsurgicaloperations.
Suf-ficienttreatmentofpostoperativepaininchildrenisamain
concernforpatients,parentsandclinicians.1However,
suc-cessfultreatment of postoperativepainin childrenis still difficultdespiteofrecent progressincontroltechniqueof painandanalgesics.Insufficientpostoperativepaincontrol can result in impairment of the feature of life, recov-eryof patientsandsocial stressfor boththechildren and the parents.1 Analgesics such as opioids and non-opioids
are frequently used for postoperative pain management. The severity of side effects related witheffective opioid dosage may restrict their usage for sufficient postopera-tive pain control. Intravenous (IV) non-opioid analgesics are used extensively for the treatment of postoperative pain. Non-opioid analgesics have been shown to effec-tively decrease postoperative pain, opioid consumption and thus their adverse effects during the postoperative periodinchildren.2 Thereareonlyafewalternative
anal-gesicagents forIVnon-opioidanalgesiafor thetreatment of postoperative pain in pediatric patient.2 Paracetamol
(acetaminophen)2---6 and dipyrone (metamizol)7---9 are two
frequently usedIVnon-opioid analgesics.10,11 Paracetamol
is the most popular,effective andmost widely used non-opioid analgesic for acute pain.11 Dipyrone has potent
pain-relieving, antipyretic, spasmolytic properties, and is
also an effective non-opioid analgesic for acute pain.11
Paracetamol and dipyrone generally show similar clinical efficacy.5,12 On theother hand,administrationof
paracet-amol resulted in a significant reductionin the number of patients requiring opioid analgesics to achieve adequate postoperativepainreliefwhencomparedwithdipyrone.13
IV-PCA is an effective method for the treatment of post-operative pain both in adults and children.2 IV-PCA is an
effectiveand safemethodproviding appropriatelevelsof analgesiainchildrenover5yearsofage.14,15Theliterature
reviewrevealsthatthereareafewstudiesconductedwith non-opioidanalgesicsbyIV-PCAfortreatmentof postopera-tivepaininonlyadults.16---21Althoughnon-opioidanalgesics
(paracetamolanddipyrone)arewidelyusedinthepediatric agegroup, surprisinglywe have notseen anyreport con-cerningnon-opioidanalgesic(paracetamolordipyrone)use viaIV-PCAforpostoperativepaintreatmentinchildren.
In our study,we aimed to test the hypothesis that IV-PCAwithparacetamolfor treatmentofpostoperativepain inchildrenaftertonsillectomyissuperiorandanacceptable alternativefordipyronebyIV-PCAintermsofanadequate postoperativepain relief and reduction in the number of patientsrequiringopioidanalgesics.
Methods
Writteninformedparentalconsentandverbalchildassent were obtained from 143 ASA I patients (according tothe AmericanSocietyofAnesthesiologistsPhysicalStatus Classi-ficationsystem;aged7---15years)whohadbeenscheduled for elective tonsillectomy. The study was a prospective, randomized, placebo-controlled double-blind study. Patientswereinstructed howto usea PCA pump prior to surgeryandwereinformedabout thedatatobecollected postoperativelyusinga visual analog scale (VAS)and pain reliefscore (PRS).Exclusioncriteriaincluded ahistory of significant hepatic, pulmonary, renal, or cardiac disease; hypersensitivity to the study medications; any disorder contraindicating administration of non-opioid analgesics; pepticulcerdisease;asthma;ableedingdisorder; concomi-tant medication (anticonvulsants, corticosteroids, psycho tropics, or antihistamines); intolerance to non-opioids. Those unable to understand the instructions regarding the use of PCA were not included in the study. Patients were not allowed to receive any analgesics 24h prior to the operation. Patients were assigned randomly to 1 of 3 study groups, according to a pre-generated randomiza-tionscheme created by the web site Randomization.com
(http://www.randomization.com), to receive IV-PCA
treatment with paracetamol, dipyrone, or placebo (0.9% NaCl).
Theanalgesicsolution(500mL0.9%NaCl)wasprepared by one of the researchers (AK) blinded to the treatment protocol andnot involved in the intraoperative and post-operative patient treatment. Patients were blind to the treatment. Postoperative data were collected by another anesthesiologist(EC)blindedastowhichanalgesicwasused. The solutions contained either 2mgmL−1 paracetamol, 2mgmL−1 dipyrone, or 1mL normal saline. No premedi-cation wasgiven tothe children. General anesthesia was inducedwiththiopental(5---7mgkg−1),fentanyl(1
gkg−1),
and vecuronium (0.1mgkg−1). After tracheal intubation, mechanicalventilationwasinitiated,anda50%mixtureof N2O/O2wasadministeredthroughoutthesurgery. Anesthe-siawasmaintainedwithisoflurane1.2MAC.Residualmuscle relaxationwasreversed withneostigmineand atropineat the end of the operation. All patients were extubated in theoperatingroom.Patients wereassignedtoone ofthe following 3 groups with respect to the analgesic agent administeredviaIV-PCA(AbbottPainManagementProvider, AbbottLaboratories,AbbottPark,Ill,USA)intherecovery room:
Paracetamol:Loadingdoseof4.5mgkg−1IV,followedby 0.5mgkg−1h−1 basalinfusion,1mgkg−1bolusdose, lock-out time30min for 24h (totaldose of paracetamol was limitedto10mgkg−14h−1).
Dipyrone: Loading dose of 4.5mgkg−1 IV, followed by 0.5mgkg−1h−1 basalinfusion,1mgkg−1bolusdose, lock-outtime30minfor24h(totaldoseofdipyronewaslimited to10mgkg−14h−1).
Placebo: Loading dose of 2mLkg−1 IV, followed by 0.5mLkg−1h−1 basalinfusion,1mLkg−1bolusdose, lock-outtime30min.
Postoperativepainintensitywasevaluatedbythepatient accordingtoa0-to100-mmhorizontalVASat30min,1,2,4, 6,12,and24hpostoperatively.PRS(PainReliefScore)was
evaluatedbythepatientaccordingtoa0=none,1=little, 2=some,3=alot,and4=completereliefat30min,1,2,4, 6,12,and24hpostoperatively.Pethidine(0.25mgkg−1)was given IVtopatients whose VASscore was≥40mm and/or PRS was <2 and then recorded (total dose of pethidine waslimitedto1.5mgkg−16h−1).Adverse effectsincluding nausea,vomiting,bleedingatthesurgicalfield,dyspepsia, allergicreactions,anduseofantiemeticmedication (meto-clopramide HCl) also were recorded during the first 24h postoperatively.
Apoweranalysiswasperformedbasedonthetotal pethi-dinerequirement dataobtainedfromthefirst15 patients in the placebo group. The results of the first 15 patients in the placebo group showed that mean total pethidine requirement was 0.81±0.39mgkg−1 during the first 24h postoperatively.Ifwealsoassumedatwo-tailedtypeIerror of0.05andapower of0.80,approximately40patients in each groupwererequiredin ordertodetecta 30% reduc-tioninthedoseoftotalpethidinerequirementbetweenthe groups.Analysiswasperformed byPowerandPrecisionV4 TM (version 4.1.0,Biostat Inc.,Englewood, NJ) statistical program.
AllstatisticalcalculationswereperformedusingSPSSfor Windows software (Statistical Package for the Social Sci-ences,version11.0,SSPSInc,Chicago,IL,USA).Differences between the 3 groups were analyzed using an analysis of variance (ANOVA) test or its nonparametric counterpart, the Kruskal---Wallis test. Post hoc analysis was performed using the Bonferroni test. Homogeneity of variances was calculatedusingLevene’stestandLillieforssignificance cor-rection. Chi-square or Fisher’s exact tests were used to analyzecategorical variableswhereappropriate.Dataare expressedasmeans±SD.Differenceswereconsidered sta-tisticallysignificantatlevelsofp<0.05.
Results
Enrollment
Allocation
Follow-Up
Analysis Assessed for eligibility (n=143)
Excluded (n=23)
♦ Not meeting inclusion criteria (n=8) ♦ Declined to participate (n=9) ♦ Other reasons (n=6)
♦ Did not receive placebo (n=0) ♦ Received placebo (n=40) Placebo(n=40)
Discontinued dipyrone (n=0) Lost to follow-up (n=0)
Discontinued placebo (n=0) Lost to follow-up (n=0)
Discontinued paracetamol (n=0) Lost to follow-up (n=0)
Analysed (n=0) Analysed (n=0) Analysed (n=0) ♦ Did not receive dipyrone (n=0)
♦ Received dipyrone (n=40) Dipyrone (n=40)
Paracetamol (n=40)
♦ Received paracetamol (n=40)
♦ Did not receive paracetamol (n=0)
♦ Excluded from analysis (n=0) ♦ Excluded from analysis (n=0) ♦ Excluded from analysis (n=0) Randomized (n=120)
Figure1 Enrolmentprocess.
Table1 Demographicandbaselineclinicalcharacteristicsofthepatients.
Paracetamol(n=40) Dipyrone(n=40) Placebo(n=40)
Age(year) 9.4±2.2 8.8±2.2 9.2±2.3
Weight(kg) 33.2±12.9 30.6±11.1 32.2±12.3
Sex(male/female,n) 20/20 20/19 23/17
Durationofsurgery(min) 39.1±15.4 43.0±13.0 37.3±13.9
Valuesaremeans±SDornumbersofpatients,asappropriate.
Table2 Meanpainscores(VAS)foreachoftheindicatedtimes.
Paracetamol(n=40) Dipyrone(n=40) Placebo(n=40) p
VAS30min. 40.4±30.6 39.8±31.9a 56.6±27.2a 0.044a
VAS1h 16.8±18.8 21.8±11.1 24.1±25.5 0.340
VAS2h 16.4±15.0 28.1±26.2 23.5±25.3 0.173
VAS4h 18.3±15.9 26.1±28.5 26.1±25.3 0.645
VAS6h 17.5±15.8b 20.9±22.4a 30.1±23.3a,b 0.045a/0.013b
VAS12h 19.6±18.1 16.1±15.4 24.5±24.9 0.549
VAS24h 11.9±11.7 11.2±8.9 19.4±19.1 0.244
Dataaremean±SD.VAS,visualanalogscale(VASvaluesobtainedfromeachgroupwerecomparedwiththeothertreatmentsateach timepointusingananalysisofvariance).
4
3
2
1
0
30.min 1.h 2.h 4.h 6.h 12.h
P
ain relief score
Paracetamol Dipyrone Placebo
Figure2 Painreliefscoresofthepatientsinthegroupsduring postoperative24h.
The requirement for postoperative cumulative amounts of rescue analgesics for the paracet-amol (0.38±0.38mgkg−124h−1) and dipyrone (0.39±0.41mgkg−124h−1) groups was significantly lower thanthoseoftheplacebogroup(0.65±0.46mgkg−124h−1) (paracetamol vs plasebo, p=0.013; dipyrone vs placebo,
p=0.023, Fig. 3). Fifteen patients (37.5%) in the para-cetamol, 13 patients (32.5%) in the dipyrone, and 4 patients(10%)intheplacebogroupdidnotrequirerescue analgesics during the 24h after surgery. The amount of rescueanalgesicsfortheparacetamolanddipyronegroups was significantly lower than those of the placebo group (paracetamol vs plasebo, p=0.004; dipyrone vs placebo,
p=0.014,Fig.4).
Themostfrequentadverseeffectswerenausea(15.8%) and vomiting (29.2%) during the first 24h after surgery. Nosignificantdifferenceswerefoundbetweengroupswith respect to nausea, vomiting and antiemetic medication
0.9 1
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
30.min 1.h 2.h 4.h 6.h 12.h 24.h
Placebo Dipyrone Paracetamol
P
ethidine (mg/kg) *
*
€
£
€ €
Figure3 Totalopioidrequirementsofthepatientinthegroup during postoperative 24h. Values obtained from each group werecomparedwiththeothertreatmentsateachtimepointvia analysisofvariance.*P<0.05paracetamolanddipyroneversus placebo.£P<0.05dipyroneversusplacebo;DP<0.05
paraceta-molversusplacebo.
40
35
30
25
20
15
10
5
0
Paracetamol Dipyrone
Numbers of the resuce opioid analgesics
needed patients
Placebo
∗
Dipyrone Placebo Paracetamol
Figure4 Rescue analgesicsrequirementsofthepatientsin thegroupsduringpostoperative24h.
(p>0.05,Fig.5).Adverseeffectsincludingpersistent nau-seaandvomiting,bleedingatthesurgicalfield,dyspepsia, and allergic reactions were not recorded during the first 24h postoperatively. With respect to adverse effects, no significantdifferencewasfound amongthegroups studied (p>0.05).
40
30
20
10
0
Paracetamol Dipyrone Placebo
Nausea
Vomiting
Antiemetic
Numbers of patients (n)
Discussion
Ourstudyrevealedthattheadministrationofparacetamol anddipyronebyIV-PCAforthetreatmentofacute postop-erativepainresultedinawell tolerabilityandhadsimilar effective analgesic properties in children after tonsillec-tomy.The rescue opioidanalgesic requirementduring the first24haftersurgerywassignificantlylowerinthe paracet-amolanddipyronegroupswhencomparedwiththeplacebo group.
IV-PCA is an effective method used for the treatment of postoperative pain in adults and children, while regu-lating the dose according toindividualneeds, anditsuse hasexpandedtoevenyoungchildren.2,14,15 Insomeof the
studies,18---21 dipyrone was successfully used in adults by
IV-PCA for postoperative pain management. Although, IV paracetamolanddipyronearewidely usedinchildren,we havenotencounteredanyreportconcerningparacetamolor dipyroneusebyIV-PCAforpostoperativepaintreatmentfor thisgroupofage.Ourstudyisthefirstprospective, random-ized, double-blind, placebo-controlled study to compare IV-PCA with paracetamol and dipyrone for postoperative painmanagementinchildren.Furtherstudiesmaybe warr-antedwith variousdoses of paracetamol and dipyroneto definetheoptimumIV-PCAregimenforpostoperativepain managementinchildren.
Why do practitioners administer IV non-opioids inter-mittently by bolus injection with hand-held injector for acutepostoperativepaintreatmentinpatientsthatalready receives intra-operatively non-opioids intravenously and then continued every 6h for 24h? Markedly high andlow levelsofanalgesicdrugsmayresultassuboptimal manage-mentof postoperativepainwiththeintermittentIVbolus technique. We think that IV non-opioid analgesics should be administered by IV-PCA for acute postoperative pain treatmentwhenappropriate.Non-opioidanalgesics admin-isteredvia IV-PCA shouldhave well tolerability properties and low incidences of adverse effects. Paracetamol is a safe and well tolerated drug with minor adverse effects andprovenefficacywhenusedperioperatively.22---24IV
para-cetamolhassignificantlyincreasedtheuseofperioperative analgesic.22---24 IVformofparacetamolseemstoresultina
betteranalgesiceffectwhencomparedwithotherforms.6
Dipyrone is a widely used effective analgesic with low adverseeffects.2Inourstudy,adverseeffectsincluding
per-sistentnauseaandvomiting,bleedingatthesurgicalfield, dyspepsia,andallergicreactionswerenotencountered dur-ing the first 24h postoperatively. In addition tothis, the incidenceofnausea,vomitingandtheneedforantiemetic medicationweresimilarinstudydrugsandplacebogroups. Inourstudy,wearesurprisedthatthereisnodifferencein theincidenceofsideeffectsintheplacebo,paracetamol, anddipyronegroups.Sincetheplacebogroupconsumed sig-nificantlymorepethidinethantheothergroups.Wewould haveexpectedalowerincidenceofnauseaandvomitingin thetwoPCAgroupssincetheyconsumedlesspethidine.We thinkthattheincidenceofpostoperativenauseaand vomi-ting(PONV)isnotonlyrelatedtostudymedicationbutitis alsorelatedtothetypeofsurgery astonsillectomy. Para-cetamolanddipyronearerelatively well toleratedagents whencomparedwiththeother non-opioidanalgesicswith respecttopotentialsideeffects.25,26Wedidnotencounter
any complication related with paracetamol and dipyrone withoutPONV.IVdipyroneandparacetamolarecommonly usednon-opioidanalgesicsastheprimaryanalgesicor adju-vanttoopioidanalgesiaforpostoperativepainmanagement inchildhoodinourcountry.
IVparacetamolandtramadolhavesimilaranalgesic prop-ertiesafteradenotonsillectomyinchildren.3 Dipyroneand
tramadol can be considered as alternative analgesics for treatmentofpostoperativepainwhenadministeredby IV-PCA.20 IV dipyrone has been revealed to be an effective
analgesic6,18---21,27 andhas equivalentefficacytothat of IV
paracetamolfor postoperativepaintreatment5,12 Korkmaz
Dilmenetal.28demonstratedthatIVparacetamoland
dipy-roneprovideeffective analgesiaafterlumbardisksurgery whenadministratedasrescue analgesic withmorphineby PCA.On the other hand,Grundmann etal.25 showedthat
dipyroneis superior to paracetamol for acute postopera-tivepaintreatment.However,theirpostoperativefollowup periodwaslimitedto2handwasrelativelyshortwhen com-paredwithourstudy.Inourstudy,painscoresinparacetamol anddipyronegroupswerelowandsimilaroverthecourseof theassessmentperiodandthedifferencebetweenthetwo groups with respect torescue analgesic requirement was notsignificant. Ourresults suggest that administrationof paracetamolanddipyronebyIV-PCAarebotheffectiveand havesimilaranalgesicpropertiesforthetreatmentofacute postoperativepainfollowingtonsillectomyinchildren.
PONV are frequent postoperative problems following general anesthesia especially after tonsillectomy. Use of opioid analgesic is an important factor in increasing risk ofPONV.Therisk ofPONVdependsonmanyotherfactors suchasthe patient,technique of theanesthesia, typeof surgery,andmedicationsadministered.29Inadditiontothis,
swallowedbloodandoropharyngealirritationinduce vomi-ting after tonsillectomy in children.30 Adenotonsillectomy
hasthehighest rateof PONV (54%)amongthe most com-monlyperformed operationsin children.31 Brodner etal.5
demonstratedthat episodesof nausea andvomiting were notsignificantintheparacetamolanddipyronegroupwhen comparedwithplacebogroupafterminortointermediate surgery.Theyshowthattheincidenceofsideeffectswasnot significantamongthegroups;therangeofrelative frequen-ciesfornauseawasbetween30.6%and42.9%andtherange ofrelativefrequenciesforvomitingwasbetween18.4%and 24.5%.8Uysaletal.3 showedthatthefrequencyof nausea
andvomitingare22%and19%respectivelyinIV paraceta-molgroupafteradenotonsillectomyinchildren.Inourstudy, nauseadevelopedin15.8%patientsandvomitingin29.2%, butthoseweretheonlyadverseeffectsexperiencedbyour patients.Our results revealed findings similartothose of previousstudies,andwe thinkthattheincidenceofPONV isnotonlyrelatedtostudymedicationbutitisalsorelated tothetypeofsurgery.
Inconclusion,bothparacetamolanddipyronehavegood tolerabilityprofileandhaveeffective analgesicproperties when administered by IV-PCA for postoperative analgesia aftertonsillectomyinchildren.
Funding
Conflicts
of
interest
Theauthorsdeclarenoconflictsofinterest.
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