Rev. bras. ortop. vol.50 número6

w w w . r b o . o r g . b r

Original

Article

Length

of

preoperative

hospital

stay:

a

risk

factor

for

reducing

surgical

infection

in

femoral

fracture

cases

Hoberdan

Oliveira

Pereira

_,

_Edna

_Maria

_Rezende

_,

Bráulio

Roberto

Gonc¸alves

Marinho

Couto

a_{DepartmentofNursing,FederalUniversityofMinasGerais(UFMG),BeloHorizonte,MG,Brazil}

b_{InstituteofEngineeringandTechnology,UniversityCenterofBeloHorizonte(UNIBH),BeloHorizonte,MG,Brazil}

a

r

t

i

c

l

e

i

n

f

o

Articlehistory:

Received23September2014 Accepted14November2014 Availableonline23October2015

Keywords:

Infectionoftheoperativewound Femoralfractures

Riskfactors

a

b

s

t

r

a

c

t

Objective:Toanalyzeinfectionsofthesurgicalsiteamongpatientsundergoingclean-wound surgeryforcorrectionoffemoralfractures.

Methods:Thiswasahistoricalcohortstudydevelopedinalarge-sizedhospitalinBelo Hor-izonte.DatacoveringtheperiodfromJuly2007toJuly2009weregatheredfromtherecords inelectronicmedicalfiles,relatingtothecharacteristicsofthepatients,surgicalprocedures andsurgicalinfections.Theriskfactorsforinfectionwereidentifiedbymeansofstatistical testsonbilateralhypotheses,takingthesignificanceleveltobe5%.Continuousvariables wereevaluatedusingStudent’sttest.Categoricalvariableswereevaluatedusingthe chi-squaretest,orFisher’sexacttest,whennecessary.Foreachfactorunderanalysis,apoint estimateandthe95%confidenceintervalfortherelativeriskwereobtained.Inthefinal stageofthestudy,multivariatelogisticregressionanalysiswasperformed.

Results:432patientswhounderwentclean-woundsurgeryforcorrectingfemoralfractures wereincludedinthisstudy.Therateofincidenceofsurgicalsiteinfectionswas4.9%and theriskfactorsidentifiedwerethepresenceofstroke(oddsratio,OR=5.0)andlengthof preoperativehospitalstaygreaterthanfourdays(OR=3.3).

Conclusion:Topreventsurgicalsiteinfectionsinoperationsfortreatingfemoralfractures, measuresinvolvingassessmentofpatients’clinicalconditionsbyamultiprofessionalteam, reductionofthelengthofpreoperativehospitalstayandpreventionofcomplications result-ingfrominfectionswillbenecessary.

©2015SociedadeBrasileiradeOrtopediaeTraumatologia.PublishedbyElsevierEditora Ltda.Allrightsreserved.

∗ _{Correspondingauthor.}

E-mail:hoberdanoliveira2013@gmail.com(H.O.Pereira). http://dx.doi.org/10.1016/j.rboe.2015.09.006

Tempo

de

internac¸ão

pré-operatório:

um

fator

de

risco

para

reduzir

a

infecc¸ão

cirúrgica

em

fraturas

de

fêmur

Palavras-chave:

Infecc¸ãodaferidaoperatória Fraturasdofêmur

Fatoresderisco

r

e

s

u

m

o

Objetivo:Analisarasinfecc¸õesdesítiocirúrgicoempacientessubmetidosacirurgiaslimpas paracorrec¸ãodefraturasdefêmur.

Métodos: EstudotipocoortehistóricadesenvolvidoemumhospitaldegrandeportedeBelo Horizonte.Acoletadosdadosfoifeitanosregistrosdosprontuárioseletrônicos,dejulho de2007ajulhode2009.Foramcoletadosdadosreferentesàscaracterísticasdospacientes, dosprocedimentoscirúrgicosedasinfecc¸õescirúrgicas.Osfatoresderiscoparainfecc¸ão foramidentificadospormeiodetestesestatísticosdehipótesesbilaterais,considerando níveldesignificânciade5%.AsvariáveiscontínuasforamavaliadasportestetdeStudent. Asvariáveiscategóricasforamanalisadaspormeiodetestedequi-quadradoouexatode Fisher,quandonecessário.Paracadafatorsobanálise,foiobtidaumaestimativapontual eporintervalosdeconfianc¸ade95%paraoriscorelativo.Naúltimaetapadotrabalho,foi feitaumaanálisemultivariada(regressãologística).

Resultados: Foramincluídosnesteestudo432pacientessubmetidosacirurgiaslimpasde correc¸ãodefraturadefêmur.AtaxadeincidênciadeISCfoide4,9%eosfatoresderisco identificadosforamapresenc¸adeacidentevascularcerebral(razãodaschances–OR=5)e períododeinternac¸ãoatéacirurgiaacimadequatrodias(OR=3,3).

Conclusão:Paraaprevenc¸ãodasinfecc¸õesdesítiocirúrgico(ISC)dascirurgiasdefraturasde fêmurserãonecessáriasmedidasqueenvolvamaequipemultiprofissionalnaavaliac¸ãodas condic¸õesclínicasdospacientes,reduc¸ãodotempodeinternac¸ãoatéacirurgiaeprevenc¸ão dascomplicac¸õesdecorrentesdasinfecc¸ões.

©2015SociedadeBrasileiradeOrtopediaeTraumatologia.PublicadoporElsevier EditoraLtda.Todososdireitosreservados.

Introduction

Surgicalsiteinfection(SSI)isadisastrousadverseeventfor bothpatients andsurgeons, especiallyin clean surgeryfor open reductionoffractures ofthe femurand hip. InLatin America,thefinancialcostsinvolvedinfracturesofthe prox-imalfemurwereassessedbetween1980and2003andwere foundtorangefromUS$4500toUS$6000perpatient.InBrazil, theseamountsmayreachUS$5500perpatient.1_Everyyear,

theBrazilianNationalHealthSystem(SistemaÚnicodeSaúde, SUS)undertakesgreaternumbersoftreatmentsonfemoral fractures in elderly patients. In 2009, the expenditure was approximatelyR$57.61milliononadmissionsversusR$24.77 milliononmedicationsfortreatingosteoporosis,whichisan importantcauseoffemoralfractures.In2006,these expendi-tureshadbeenR$49millionandR$20million,respectively. Hannanetal.,2 _{statedthatthesocialandeconomiccostof}

femoralfracturesbecomesevengreaterbecauseafteraperiod of hospitalization, elderly patients need intensive medical careandlongperiodsofrehabilitation,andalsopresentahigh mortalityrate.Thetreatmentformostfemoralfracturesis sur-gical.Inusingnewmaterialsforreplacingprostheses,lower complicationratesthroughbettertechnologyanddesignare sought.Accordingtothepotentialofsurgicalproceduresfor woundcontamination,theycanbeclassifiedasclean, poten-tiallycontaminated,contaminatedorinfected.Arrowsmith3

notedthatcleansurgicalproceduresoughttohavelower inci-denceofsurgicalsiteinfection(SSI)becausetheypresented

lowerriskofcontaminationthanothercategories.Such pro-ceduresareconsideredtobemarkersofservicequalityand presentbetterexecution(elective,non-traumatic,tissuesthat areeasilydecontaminatedandintactskin).Therateof inci-denceofSSIshouldbelessthan2%.

Several risk factors relating to the patient and to the surgicalprocedure havebeen correlatedwiththeincidence ofSSIinfemoralfractures.Theintrinsicfactors relatingto elderlypatientscompriseinadequatenutritionalstatus, dia-betes mellitus (DM), use of tobacco, obesity, surgical site infection,colonizationoftheskin,immuneresponseand pro-longedperiodofpreoperativehospitalization.1_Theextrinsic

factors associatedwiththeoperationandthe patient com-priseskinpreparation,appropriateclothes,preparationofthe surgicalteam’shands,durationoftheoperation,surgical tech-nique,processingofmaterialsandarticles,preparationofthe antibioticand preparationofthesurgicalsite. Controlover thesefactorsisessentialforminimizingthecontamination ofthesurgicalsite.4_{Studieshaveemphasizedtheneedto}

pri-oritizecareforpatientswithfemoralfractures,especiallyin relationtothetimethatelapsedbetweenthefractureandthe surgicalprocedure.5

increasethepatient’sriskofdeathafterthesurgery?(4)Does SSIincreasethepatient’slengthofhospitalstay?and(5)What aretheriskfactorsassociatedwithSSIafteropenreductionof femoralfractures?

Materials

and

methods

ThiswasaprospectivecohortstudyconductedtoanalyzeSSI andits riskfactorsamongpatientswho underwent correc-tionoffracturesofthehipandfemur,betweenJuly2007and July2009.Thestudy wasconductedinalarge-sized hospi-tal,withacapacityforaround350beds,whichisareferral centerforaccidentsandemergenciesinthestateofMinas Gerais, Brazil. The sample was composed of 432 patients whounderwentelectivesurgerytocorrectfemoralfractures. Theresponsevariablescomprisedsurgicalsiteinfectionand hospitaldeath. Thepreoperativeand operativeparameters weredividedintocategoricalandcontinuousvariables.The continuous variables studied were age, duration of preop-erative hospitalization and duration of the operation. The categoricalvariableswere sex,typeofsurgery, shiftduring whichtheoperationwasperformed(morning,afternoonor night),typeofanesthesia,preoperativeassessmentscoreof the American Societyof Anesthesiology(ASA),Nosocomial InfectionSurveillance index, fracture classification, typeof injury, typeofosteosynthesis and typeofsurgery (elective oremergency).Thecomorbiditiesstudiedwerediabetes mel-litus(DM), congestive heart failure (CHF), systemic arterial hypertension(SAH), chronicobstructive pulmonarydisease (COPD),heartdiseases,hypercholesterolemia,alcoholabuse, psychiatricdisorders,cancerofmetabolicdisease,strokeand anemia.Thetypeofanesthesiawasclassifiedaccordingtothe combinationoftwoormoreprocedureswithorwithout seda-tion.Hospitalizationbeforesurgerywasdefinedasuptofour daysbeforeitormorethanfourdaysbeforeit.6_Theduration

ofthesurgerywasstratifiedaslessthanorequalto138minof morethanthisduration.TheASAscorewascategorizedinto levelsI_,II_,III_andIV_:ASAI_{forhealthypatients;}II_forpatients withmoderatesystemicdisease;IIIforpatientswithsevere preexistingsystemicdiseases thatwere notincapacitating; andIVforpatientswithlife-threateningsystemicdisease. Cat-egoryV_{-5,forindividualswithlifeexpectancyofamaximum} of24h,wasnotidentifiedinanyofthepatientsofthisstudy. Fortheindexofsurgicalriskofinfection,thescorezerowas usedandthegroupedscoreof1or2wasusedonlyforclean surgery.Theprophylacticantibioticwastestedforusebefore orduringthesurgery.

Theclassificationoffemoralfractureswasbasedonregions of the femur: fractures of the femoral neck,7 _trochanteric

fractures8 _{orsubtrochantericfractures.}9 _{Forfracturesofthe}

diaphysis,theAOclassificationwasused.10_Forsome

opera-tions,theclassificationwasnotshown.WeusedtheICD-10 tocodeandgroupthisvariable.11_{Fivetypesofosteosynthesis}

wereused:plate,nail,screw,cementandothers.Thepatients includedwerehospitalizedandunderwentcleansurgical cor-rectionoffemoralfracturesbetweenJuly2007andJuly2009.

Riskfactorsandprotectivefactorsforinfectionwere iden-tified bymeans ofstatistical testson bilateral hypotheses, inwhichthesignificancelevelwastakentobe5%(˛=0.05).

ContinuousvariableswereevaluatedusingStudent’sttestor anonparametrictest,andcategoricalvariableswereanalyzed using thechi-square orFisherexact test(whennecessary). Foreachfactorunderanalysis,apointanalysisand95% con-fidenceinterval(95%CI)fortherelativeriskwereobtained. Inthelastphaseofthestudy,multivariateanalysiswas con-ductedusinglogisticregression.Thevariablestestedinthe logisticmodelwereselectedwhentheunivariateanalysis gen-eratedavalueofp≤0.25.

Thisstudywasapprovedbythehospitalinvolved,under report no.18 and bythe researchethics committee,under CAEEreportno.0108.0.203.000-11,whichwasapprovedonMay 5,2011,inconformitywithresolution196/96.

Results

Thisstudyincluded432patientswhounderwentopen reduc-tion offemoral fractures between July 2007and July 2009. Fallingfromastandingposition,fallingfromabedandfalling from a staircase were the most frequent types of trauma amongthepatientswithfemoralfractureswhowere evalu-ated.Thesepatientsaccountedfor59%ofthecasesandwere followed bythose involvedinmotorcycleaccidents(15.5%). Thepatients’lengthofhospitalstayrangedfromoneto139 days,withamedianofeightdays.Themeantimespentin hos-pitalbeforethesurgerywasfivedaysand43%ofthepatients wereinhospitalforuptofourdays.Thepatients’meanlength ofstayinthesurgicalcenterwassixhours.Themean dura-tionoftheoperationwasonehourand50minandmorethan 70%oftheoperationslastedfornotmorethan138min.Most ofthepatientswereovertheageof60years;36%cametothe hospitalviaanemergencyunit;and5%presentedmorethan twodiagnosesatthetimeofhospitaladmission(Tables1–3).

Amongthe432patientswhounderwentcorrectionofclean fracturesofthefemur,21patientswererecordedaspresenting SSI.Theriskofinfectionwas4.9%.

Strokeandlengthofstaygreaterthanfourdayspresented statisticallysignificantassociationswithSSI(Table4).

Itwasfoundthatforthepatientswithstrokewhoremained inhospitalformorethanfourdays,theexpectedriskof acquir-ing infection was almost threetimes greater than the risk amongthosewhohadthisdiseasebutwereinhospitalfornot morethanfourdays.Strokeandlengthofhospitalstayuntil thesurgerywerethevariablesassociatedwithSSI(Table5).

Regardinghospitalmortalityaftersurgicalcorrectionofthe femoralfracture,SSIwasnotassociatedwiththechanceof death(p=0.125)(Table6).

In10ofthe21casesofinfectionregistered,theetiological agentremainedunidentified.Staphylococcusaureusand Acine-tobacterbaumanniiwerethemicroorganismsmostfrequently identified.Only2%ofthe432patientspresentedpreoperative colonization,whichwasmostlydetectedbymeansofnasal andaxillaryswabs(Table7).

Discussion

Table1–Opensurgeryforcorrectingfemoralfracturesinatertiary-levelhospital:patients’characteristicsandsurgical characteristics(July2007–July2009).

Variable Frequency % Mean Median Minimum Maximum SD

Sex

Female 208 48.1

Male 224 51.9

Age(years) 57 66 4 102 27.3

Age(years)

<20 55 12.7

20–39 80 18.5

40–59 55 12.7

60–79 122 28.2

≥80 120 27.8

Lengthofhospitalstay(days) 14 8 1 139 19.4

Lengthofhospitalstaybeforesurgery(days) 8 5 0 234 14.1

Lengthofhospitalstaybeforesurgery(days)

Upto4 185 42.8

Morethan4 247 57.2

Durationofsurgery(h) 1:50 1:40 0:10 8:20 1:01

Durationofsurgery(min)

Upto138 320 74.1

Morethan138 112 25.9

ASA–AmericanSocietyofAnesthesiology(score)

I _{174 42.8}

II _{156 38.3}

III _{70 17.2}

IV _{7 1.7}

Typeofsurgery

Elective 373 86.3

Emergency 59 13.7

Timeofdayofthesurgery

Morning 216 50

Afternoon 195 45.1

Night 21 4.9

Typeofosteosynthesis

Plate 224 52.2

Nail 105 24.5

Screw 51 11.9

Other 27 6.3

Cement 22 5.1

SD,standarddeviation.

emphasizingthattherateofSSIincleansurgeryinthis hos-pitaloverthesameperiodofJuly2007toJuly2009,takinginto accountallbodyareasandspecialties,suchasorthopedics, plasticsurgery,generalsurgeryandneurosurgery,was approx-imately2.2%.ItisnecessarytoinvestigatetheratesofSSIper surgeonandtomonitortheriskfactorsrelatingtopatientsand tothe surgicalprocedure.Efficientmonitoringsystemsand informationforsurgeonsregardingtheirinfectionrateshave demonstratedbetterpreventionofSSI.Theinfectionratescan bereducedbymorethanonethirdthroughprogramsand per-sonnelwhoaretrainedinmonitoringandinfectioncontrol.13

Thestudypopulationwascomposedofpatientswhowere mostlymale,includingadolescents,youngadultsandelderly individualsovertheageof60years,perhapsbecausethisisa referralhospitalforattendingtoemergencies.However,many authorsconsiderthatwomenarethegroupmostsubjectto femoralfractures,1_{andthatstudyshowedagreaterriskofSSI.}

Pereira14_{studiedgroupsofelderlypeopleandfoundthatthe}

rateofincidenceofhipfracturesamongwomenwas72.76%. The classification for the femoral fractures was estab-lishedinaccordancewiththeregionaffected:femoralneck, trochanterorsubtrochantericdiaphysis.Munizetal.15_showed

thatthemaintypesoffractureweretranstrochanteric(58.73%) and femoralneck(38.20%),whichare consideredtobedue to low-energy trauma. In the present study, trochanteric fractureshadhigherfrequency,butdiaphysealfractures pre-sentedhigherriskofSSI,albeitwithoutstatisticalsignificance. The length of hospital stay after the operation (four days)wasstatisticallysignificant inourunivariateanalysis (p=0.018).Thisassociationwasmaintainedinthe multivari-ateanalysis,thusconfirmingthepresenceofthisriskfactorfor SSI.Prolongedpreoperativehospitalstayhasbeencorrelated withariskofSSI.6_{Thedurationoftheoperationwasassessed}

Table2–Univariateanalysisonthecategoricalvariables:lengthofpreoperativehospitalstaygreaterthanfourdaysand strokewereriskfactorsforSSI,aftersurgerytocorrectfemoralfractures,atthe5%significancelevel(p<0.05)(July 2007–July2009).

Variable Totalnumber ofpatients

Totalnumberof caseswithSSI

RiskofSSI(%) Relativerisk 95%CI pvalue

Lengthofhospitalstaybeforesurgery(days)

Upto4 185 4 2.2

Morethan4 247 17 6.9 3.2 [1.09–9.30] 0.018

Stroke

Yes 22 4 18.2 4.4 [1.61–11.93] 0.017

No 410 17 4.1

Sex

Female 208 14 6.7 2.2 [0.89–5.23] 0.064

Male 224 7 3.1

Typeoftrauma(ICD-10)

V87 29 2 6.9 1 – 0.734

W01 230 12 5.2 0.8 [0.31–5.61]

W06.0 14 1 7.1 1 [0.10–9.77]

W10 11 0 0.0 0. –

Y30 20 2 10.0 1.5 [0.11–4.50]

V23 67 3 4.5 0.6 [0.27–8.73]

Other 61 1 1.6 0.2 [0.40–44.53]

Fractureclassification

Tronzo 150 4 2.7 1 – 0.475

Garden 105 7 6.7 2.5 [0.12–1.33]

AO 100 7 7 2.6 [0.11–1.27]

Seinsheimer 32 1 3.1 1.2 [0.10–7.38]

Other 45 2 4.4 1.7 [0.11–3.17]

Durationoftheoperation(min)

Upto138 320 13 4.1 0.6 [0.24–1.34] 0.147

Morethan138 112 8 7.1

ASA

I _{174 6 3.4 1 – 0.169}

II _{156 12 7.7 2.2 [0.17–1.17]}

III _{70 2 2.9 0.8 [0.25–5.84]}

IV _{7 1 14.3 4.1 [0.03–1.74]}

Typeofsurgery

Elective 373 20 5.4 3.2 [0.43–23.13] 0.191

Emergency 59 1 1.7

Timeofdayofthesurgery

Morning 216 9 4.2 1 – 0.367

Afternoon 195 12 6.2 1.5 [0.29–1.57]

Night 21 0 0 0 –

Diabetesmellitus(DM)

Yes 26 2 7.7 1.6 [0.40–6.68] 0.365

No 406 19 4.7

Congestiveheartfailure

Yes 9 0 0 0 – 0.635

No 423 21 5

Cardiopathy

Yes 16 0 0 0 – 0.444

No 416 21 5

Hypertension

Yes 148 9 6.1 1.4 [0.62–3.34] 0.264

No 284 12 4.2

Chronicobstructivepulmonarydisease(COPD)

Table2–(Continued)

Variable Totalnumber ofpatients

Totalnumberof caseswithSSI

RiskofSSI(%) Relativerisk 95%CI pvalue

No 424 21 5

Hypercholesterolemia

Yes 3 0 0 0 – 0.860

No 429 21 4.9

Alcoholabuse

Yes 19 1 5.3 1.1 [0.15–7.68] 0.620

No 413 20 4.8

Psychiatricdisorders

Yes 18 1 5.6 1.2 [0.16–8.10] 0.599

No 414 20 4.8

Metabolicdisorders

Yes 9 0 0 0 – 0.635

No 423 21 5

Cancer

Yes 12 0 0 0 – 0.545

No 420 21 5

Typeofosteosynthesis

Plate 224 15 6.7 1 – 0.246

Nail 105 2 1.9 0.3 [0.82–15.09]

Screw 51 1 2 0.3 [0.46–25.27]

Other 27 1 3.7 0.6 [0.03–8.14]

Cement 22 2 9.1 1.4 [0.04–4.20]

Anesthesia:spinalanesthesiawithsedation

Yes 224 14 6.3 1.9 [0.76–4.71] 0.120

No 208 7 3.4

Surgicalinfectionriskindex

Score0 246 11 4.5 0.7 [0.31–1.66] 0.585

Scoreupto2 161 10 6.2

Anemia

Yes 178 10 5.6 1.4 [0.59–3.43] 0.288

No 228 9 3.9

Hematocritlessthan36mg/dL

Yes 259 15 5.8 2.1 [0.72–6.29] 0.120

No 147 4 2.7

Skincolonization

Yes 17 1 5.9 1.2 [0.17–8.57] 0.578

No 415 20 4.8

Generalanesthesia

Yes 41 2 4.9 1 [0.24–4.16] 0.620

No 391 19 4.9

ASA,AmericanSocietyofAnesthesiology;95%CI,95%confidenceinterval;SSI,surgicalsiteinfection;RR,relativerisk;ICD-10,international classificationofdiseases.

whichthenumberofminutesdefinedforthistypeofoperation was138.Althoughthisisavariableclassicallyassociatedwith SSI,itwasnotassociatedwithsurgicalinfectioninthepresent study.Longdurationofanoperationinacontaminated envi-ronment favors surgical contamination and, consequently, developmentofinfection.17

TheASAvariable,whichassessesthepatient’s preopera-tiveclinicalstatewasnotconsideredtobeariskfactorfor SSI in the present study. Although the patients were pre-dominantly gradedas ASAI, those withASA IVpresented ariskofSSIthatwasfourtimeshigher.Manyauthorshave considered that the ASAscore isa risk factor forSSI that

relatesdirectlytotheseverityofthepatient’sconditionand the risk of infection.18 _{Plates were the synthesis material}

mostused,in224cases(51%).Sakakietal.,1 _{statedthatthe}

treatment forthe majority of femoral fractures should be surgical.Conservativetreatmentshouldbereservedonlyfor someincompleteornon-displacedfractures.Theaimofthe surgeryistoreducethefractureandfixitinastablemanner, using avarietyofosteosynthesis methods.Spinal anesthe-siawithsedationistheanestheticproceduremostusedand theriskofinfectioninrelationtopatientsforwhomthiswas not usedhasbeen found tobe1.9%. Ercoleand Chianca19

Table3–Univariateanalysisonthecontinuousvariables:onlythelengthofhospitalstaybeforetheoperation(days)was associatedwithSSIaftertheoperationtocorrectfemoralfractures(July2007–July2009).

Variable SSI Numberofpatients Mean Median Standarddeviation pvalue

Lengthofhospitalstaybeforeoperation(days) Yes 9 31 21 24.9 0.008

No 193 13 8 18.8

Age(years) Yes 21 63 73 27.5 0.329

No 411 57 66 27.3

Durationofoperation(h) Yes 21 2:14 1:44 0.1 0.365

No 411 1:49 1:39 0

Hemoglobin Yes 19 11.0 10.6 1.2 0.298

No 387 11.4 11.3 2

Hematocrit Yes 19 33.0 32.5 4.1 0.323

No 387 34.3 33.9 6

Glycemia Yes 11 122.2 106.0 34.7 0.913

No 167 126.9 114.0 62

SSI,surgicalsiteinfection.

Table4–Analysisofvariance:inthefinalmodel,thelengthofhospitalstaybeforetheoperationandstrokewere independentlyassociatedwithsurgicalsiteinfectionaftertheoperationtocorrectfemoralfractures.Preoperativelength ofhospitalstaygreaterthanfourdaysincreasedthechancethatapatientwouldbeinfectedalmostthreefold(OR=3.3; p=0.037)(July2007–July2009).

Variable Regressioncoefficient Standarderrorofthe regressioncoefficient

Oddsratio pvalue

Preoperativelengthofhospital staygreaterthan4days

1.19 0.57 3.3 0.037

Stroke 1.60 0.62 5 0.009

Constant −3.96 0.52

Table5–SimulationofriskofSSI:lengthofhospitalstaybeforethesurgeryandstroke.

Typeofpatient Expectedrisk

ofSSI(%)

Numberof patients

ObservedSSI Observedrisk ofSSI(%)

Nostrokeandlengthofstayupto4days 1.9 177 2 1.1

Nostrokeandlengthofstaymorethan4days 5.9 233 15 6.4

Previousstrokeandlengthofstayuptofourdaysa _{8.6 8 – –}

Previousstrokeandlengthofstaymorethanfourdaysa _{23.6 14 – –}

a _{Smallsamplesize.}

Table6–Hospitalmortalityaftersurgerytocorrectfemoralfractures:surgicalsiteinfectionwasnotassociatedwiththe chanceofdeath(p=0.125)(July2007–July2009).

SSI Numberofpatients Hospitalmortality Riskofhospitaldeath(%) Relativerisk 95%confidenceinterval pvalue

Yes 21 3 14.3 2.6 [0.83–7.83] 0.125

No 411 23 5.6

Total 432 26 6

presented3.4timesgreaterriskofinfectionthanthosewho underwentblocking.Thedatafrom thepresent studywere insufficienttocharacterizeantibioticasaprotectionfactor, althoughthesedatasignaledthat therewere patientswho receivedcefazolinandwhopresentedariskofSSIthatwas aroundfourtimeslower.Inameta-analysis,itwasobserved thatinsurgerytofixclosedfractures,prophylaxiswitha sin-gledoseofantibioticsreduced theseverityofdeep-wound, surface-wound,urinary-tractandrespiratory-tractinfections. That analysis alsoshowed multiple-doseprevention had a similar effecton the size ofdeep-wound infection,but no significant effect on urinary or respiratory infections was confirmed.20

TheetiologicalagentsidentifiedinSSIcaseswere Staphylo-coccusaureus,AcinetobacterbaumanniiandEnterococcussp.In some cases, more than one microorganism was identified fromcultures.Itshouldbenotedthatetiologicalagentswere onlyidentifiedin11ofthe21casesthatpresentedSSI.Thislow proportionoffindingsfromtheculturesperformedexplains theabsenceoftreatmentsguidedbylaboratoryresults.

Themultivariateanalysisconfirmedthatstrokebeforethe cleansurgicalcorrectionoffemoralfractureswas character-izedasariskfactorforSSI.Inacohortstudyinvolving1379 victimsofproximalfemoralfractures,Fengetal.21_reported

Table7–Opensurgerytocorrectfemoralfracturesina tertiary-levelhospital:skincolonizationandetiological agentsofthesurgicalsiteinfection(July2007–July2009).

Variable Frequency %

EtiologicalagentidentifiedforSSI

Yes 11 52

No 10 48

Total 21 100

EtiologicalagentforSSI

Acinetobacterbaumannii 2 18

Staphylococcusaureus 2 18

Enterobactercloacae+Acinetobacter baumannii

1 9

Enterococcussp. 1 9

Escherichiacoli+Acinetobacterbaumannii 1 9

Escherichiacoli+Enterococcussp. (ESBL-producing)

1 9

Proteusmirabilis 1 9

Proteusmirabilis+MRSA 1 9

Staphylococcusaureus+Enterococcussp. 1 9

Total 11 100

Skincolonization?

Yes 9 2

No 423 98

Total 432 100

Skinmicroorganismsidentified

Staphylococcusaureus 5 55.0

Staphylococcusaureus+Enterobactersp. 2 22.0

Proteusmirabilis 1 11.0

Staphylococcusaureus+Streptococcus pyogenes

1 11.0

Total 9 100.0

ESBL, extended-spectrum beta lactamase; MRSA, methicillin-resistantStaphylococcusaureus;SSI,surgicalsiteinfection.

ormorecomorbidities,lowercognitivecapacity,weaker pre-fracture outpatient status, longer hospital stay and higher mortalityrate.

Inthe present study,patients with previousstroke pre-sentedfourtimesgreaterriskofdevelopingSSI.Aprospective studyforevaluatingtheeffectoftheanteriorpassageafter occurrences of femoral neck or intertrochanteric fractures showedthatpatientswithhistoriesofstrokeweremorelikely tobe male, haveASA gradesIIIor IV, havethree or more comorbidities,belimitedtomovingaroundathomeandbe dependentinactivitiesofdailyliving(ADLs)and instrumen-talactivities, beforethetimeofthe fracture.Thelengthof hospitalstaywassignificantlygreaterforthesepatients.22

Thelimitationofthepresentstudywasthatitwas retro-spective,withlackofinformationonthepatients’evolution overthecourseofadministrationoftheprophylactic antibi-oticsand lack ofdefinition and adherence criteria for the clinicalevaluationanddetailedhistory-taking.

Conclusion

TheriskfactorsforSSIincasesofcorrectionoffemoral frac-turesthroughcleansurgerythatwereidentifiedinthepresent study were the presence of stroke before the surgery and lengthofhospitalstaybeforetheoperationofmorethanfour

days.Thecombinedactionofthesetwofactorscontributed towardraisingtherateofSSIamongthepatientswho under-went surgerytothreetimestheexpectedrisk.Controlover the risk factors and thetime that elapses untilthe opera-tion ishighlydesirableforreducing theriskofinfectionin thesepatients.TheincidenceofSSIidentifiedincasesofclean surgery on femoralfractures presentedlevels greater than theinfectionraterecordedinthehospital.Cleansurgery per-formedon thefemurshouldbemonitoredand keptunder surveillancebecausethisisamarkerforinfectionassociated withqualitycontrolinhealthcareservices.

Conflicts

of

interest

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