SurgicalInfection(外科感染.ppt

SurgicalInfection DingYuedingyue36 DepartmentofOrthopaedicSurgerySecondAffiliatedHospitalofSunYat senUniversity Paronychia Erysipelas Gasgangrene Definition Presenceofinfectionthatmustberesolvedbysurgicalprocedureincludingtheinfectioncomplicatedwithtrauma operation burnoretal Thepathogenscausingsurgicalinfectionsarefrequentlymixed andusuallyoriginatefromthepatient sownendogenousflora Thesepathogensareopportunistic oftendependingonanacquiredepithelialdefecttocauseinfection Classification Accordingtopathogens NonspecificinfectionSpecificinfection Accordingtocourse Acuteinfection2M Accordingtooriginationofpathogens Endogenousinfection viscus Exogenousinfection Otherclassification PrimaryinfectionSecondaryinfection OpportunisticinfectionSurperinfectionNosocomialinfection fromhospital BacterialFactors Thedepositionandgrowthofbacteriawithinwoundsareaprerequisiteforthedevelopmentofinfection Thekindandnumberofbacteriacontributetotheestablishmentofinfection Studiesoftraumaticwoundsinhealthysubjectshaveshownthatbacterialcontaminationwithmorethan105organismsfrequentlycausesinfection Thedevelopmentofinfectionisalsoaffectedbythetoxinsproducedbytheorganismandtheorganismsabilitytoresistphagocytosisandintracellulardestruction Gram negativebacteriahavesurfacecomponents endotoxinorlipopolysaccharide thataretoxic Gram positivebacteriaproducepowerfulexotoxins Syndromesoftheinflammatoryresponse Systemicinflammatoryresponsesyndrome SIRS SepticaemiaSepsisSepticshock SIRS Theessentialclinicalfindingswereanabnormalbodytemperature tachycardia tachypnea andanaberrantwhitebloodcellcount Sepsis isthecircumstanceofapatientwithfindingsconsistentofSIRSandadocumentedinfection Severesepsis isdefinedasoccurringwhenapatientwithsepsishascriticalorgandysfunctionandhypo perfusionincludinghypotension Septicshock isthemostseriousclinicalproblemandexistsifapatienthasseveresepsis isresuscitatedappropriatelywithintravenousfluidinfusion andremainsinshock Deathrate SIRS7 Sepsis16 Severesepsis20 Septicshock46 Sepsis severesepsis andsepticshockcanbefurtherdividedintosubsetsofconfirmedinfectionandsuspectedinfectionsunconfirmedbypositiveculture Subclassification Systemicinflammatoryresponsesyndrome Pathophysiology Thepathophysiologyiscomplexandinvolvesallofthemultipleinterlacingandinteractingsystemsthatareinvolvedininflammationandtheresponsetoanimmuneorperfusionchallenge Thesesystemsinclude butarenotlimitedto complement cytokinecascades arachidonicacidmetabolites cell mediatedimmunity theclottingcascade andhormonalimmunemechanisms DiagnosisofSIRS Sepsis Causes Suspectintravenous IV lineinfectionswhenothersourcesofsepsisareeliminatedandtheIVlinehasbeeninfor usually morethanaweek CentralIVlinesarethelinesmostcommonlyassociatedwithbacteremiaorsepsis Patientswithanintra abdominalorpelvicsourceofinfectionusuallyhaveahistoryofantecedentconditionspredisposingtoperforationorabscess Theurinarytractsourceissuggestedbyanantecedenthistoryofpyelonephritis stonedisease congenitalabnormalcollectingsystem prostateenlargement andpreviousprostateorrenalsurgery Patientswithdiabetes systemiclupuserythematosus SLE alcoholism orwhoaretakingsteroidsalsoareatincreasedriskforbacteremia Patientswhoarehypothermicattheonsetofsepsisorsepticshockhadapoorprognosis Patientswithacorebodytemperaturebelow35 5hadahigherdeathrate 62 thanpatientswithsepsissyndromewhosebodytemperaturewasnormalorelevated 23 Organfailuredevelopamongpatientswhoexperienceprogressivedeteriorationinorganfunctionthatbeginswithinhoursofsuccessfulreversaloftheinitialevent Afteranepisodeofacutedisruptionofhomeostasis dysfunctionandfailureofoneormoreofthefollowingorgansystemsoccurs respiratory renal hepatic cardiovascular hematologic neurologic orGI Treatment Treatmentoftheinfection Thetreatmentofsepsis septicshockbeginswithprompttreatmentoftheinfectionsite Tobeeffective theproperantibioticsmustbeadministeredinadequatedosestoachievecytotoxiclevelsforinvadingorganisms Medicalcare Offersupportivetherapyaimedatmaintainingorganperfusion Providerespiratorysupport whennecessary Fungalinfection PathogensfromtheCandidagenus maybeseenfrequentlyasanopportunisticinvaderinpatientswithserioussurgicalinfectionswhohavereceivedbroad spectrumantibiotictreatmentsuppressingnormalendogenousflora Theseinfectionsarebestavoidedthroughjudicioususeofsystemicbroad spectrumantibioticsandthroughprophylaxiswithoralnystatinorketoconazolewhenbroad spectrumantibacterialtherapyisrequired Treatment Surgicalpatientswithfungalcolonizationofmultiplesitesorwithfungiinwell drainedabscesseshavebeenmanagedsuccessfullywithtotaldosesofAmphotericinrangingfrom3to5mgperkgadministeredover10to14daysforatotaldoseof300to500mg Tetanus Conception Adiseasecausedbytetanospasmin apowerfulproteintoxinproducedbyClostridiumTetani Tetanususuallyoccursafteranacuteinjury suchasapuncturewoundorlaceration EtiologyandPathophysiology TetanusresultsfrominfectionwithCtetani amobile spore forming anaerobic gram positivebacillus Thisbacillusisfoundinoronsoil manure dust clothing skin and10 25 ofhumanGItracts Thesporesneedtissuewiththeproperanaerobicconditionstogerminate theidealmediumiswoundswithtissuenecrosis Underanaerobicconditions thesporesgerminateandproduce2toxins Tetanolysin ahemolysinwithnorecognizedpathologicactivity andTetanospasmin Theactionofthelatterhelpsexplaintheclinicalmanifestationsofthedisease Tetanospasminissynthesizedasasinglechainandiscleavedtogeneratetoxinswith2chainsjoinedbyasingledisulfidebond Theheavychainisresponsibleforspecificbindingtoneuronalcellsandforproteintransport Thelightchainblocksthereleaseofneurotransmitters Thetoxinbindingmaybeirreversible recoverydependsonthesproutingofnewaxonalterminals Oncethetoxinissynthesized itmovesfromthecontaminatedsitetothespinalcordin2 14days Whenthetoxinreachesthespinalcord localizedorcephalictetanusmayoccurinitially followedbygeneralizedtetanus History Mostcasesoccurinpatientswithahistoryofonlypartialimmunization Personswhoinjectdrugsalsoconstituteahigh riskgroup Symptom Symptomsusuallybegin8daysaftertheinfection butonsetmayrangefrom3daysto3weeks Patientsmayreportasorethroatwithdysphagia earlysign Localizedtetanuscausesmusclerigidityatthesiteofsporeinoculation Theinitialmanifestationmaybelocaltetanus inwhichtherigidityaffectsonly1limborareaofthebodywheretheclostridium containingwoundislocated Physicalexamination Commonfirstsignsoftetanusareheadacheandmuscularstiffnessinthejaw ie lockjaw followedbyneckstiffness difficultyswallowing rigidityofabdominalmuscles spasms andsweating Patientsoftenareafebrile Severetetanusresultsinopisthotonos flexionofthearms extensionofthelegs periodsofapnearesultingfromspasmoftheintercostalmusclesanddiaphragm andrigidityoftheabdominalwall Lateinthedisease autonomicdysfunctiondevelops withhypertensionandtachycardiaalternatingwithhypotensionandbradycardia Opisthotonos Diagnosis Dependonclinicalfindings Laboratoryfindingsarenotdiagnosticallyvaluable Differentiation TardiveDystoniaStrychninepoisoningDentalinfections LocalinfectionsHysteriaNeoplasmsEncephalitis Complications Spasmofthevocalcordsand orspasmsoftherespiratorymusclesthatcauseinterferencewithbreathing Fracturesofthespineorlongbones HypertensionAbnormalheartbeatsComa GeneralizedinfectionPneumoniaDeath Treatment Passiveimmunizationwithhumantetanusimmuneglobulin TAT shortensthecourseoftetanusandmaylessenitsseverity Adoseof1500Uappearsaseffectiveaslargerdoses Thegoalsofpharmacotherapyaretopreventcomplicationsandtoreducemorbidity Gasgangrene Conception Aclostridialinfectiontypicallyinvolvesunderlyingmuscle isalsotermedclostridialmyonecrosis Ananaerobic gram positive spore formingbacillusofthegenusClostridiumcausesgasgangrene ThemostcommonorganismsareC perfringens C novyi andC septicum Etiologyandpathophysiology Theseorganismsareinsoil dust andisolatedfromtheGItractandthefemalegenitaltract Clostridiaareobligateanaerobes butsomespeciesarerelativelyaerotolerant Otherbacteriacapableofproducinggas andnonclostridialorganismshavebeenisolatedin60 85 casesofgasgangrene Cperfringensproducesatleast20exotoxins Theimportantexotoxinsandtheirbiologiceffectsareasfollows Alphatoxin Lethal lecithinase necrotizing hemolytic cardiotoxicBetatoxin Lethal necrotizingEpsilontoxin Lethal permeaseIotatoxin Lethal necrotizing Deltatoxin Lethal hemolysinPhitoxin Hemolysin cytolysinKappatoxin Lethal collagenase gelatinase necrotizingLambdatoxin Protease Mutoxin HyaluronidaseNutoxin Lethal deoxyribonuclease hemolytic necrotizing Lethalastestedbyinjectioninmice Anatomically theseinfectionsaremarkedbyalayerofnecrotictissue whichisnotwalledoffbyasurroundinginflammatoryreactionandthusdoesnotpresentaclearboundary Symptom Suddenonsetofpainisusuallythefirstsymptom Thepaingraduallyincreasesinseveritybutspreadsonlyastheunderlyinginfectionspreads Patientssometimesreportafeelingofheavinessintheaffectedextremity Alow gradefeverandapatheticmentalstatusmaydevelop Theseinfectionsaremarkedbytheabsenceofclearlocalboundariesorpalpablelimits Thislackofclearboundariesaccountsbothfortheseverityoftheinfectionandforthefrequentdelayinrecognizingitssurgicalnature Physicalexamination Inaddition theoverlyingskinhasarelativelynormalappearanceintheearlystagesofinfection andthevisibledegreeofinvolvementissubstantiallylessthanthatoftheunderlyingtissues Rapidprogressionofasofttissueinfection afailuretorespondtoconventionalnonoperativetherapymaybetheearliestsignsofanecrotizingsofttissueinfection Tachycardiadisproportionatetobodytemperatureiscommon andthepatientmayreportafeelingofimpendingdoom Latesignsincludehypotension renalfailure andaparadoxicalheighteningofmentalacuity Insummary thetypicalsignsandsymptomsofgasgangreneareseverepainandtenderness localswellingtomassiveedema skindiscolorationwithhemorrhagicblebsandbullae crepitus fever relativetachycardia andalteredmentalstatus Diagnosis ClinicalfindingsAGramstainoftheexudateorinfectedtissuesrevealslargegram positivebacilliwithoutneutrophils Differentials NecrotizingfascitisNonclostridialcrepitantcellulitis mycosisClostridialnecrotizingfascitis Complications MassivehemolysisDisseminatedintravascularcoagulation DIC AcuterenalfailureAcuterespiratorydistresssyndromeShock Treatment Thecombinationofaggressivesurgicaldebridementandeffectiveantibiotictherapyisthedeterminingfactorforsuccessfultreatmentofthislife threateninginfection Surgicalcare Fasciotomyforcompartmentsyndromemaybenecessaryimmediatelyandshouldnotbedelayedinpatientswithextremityinvolvement Performdailydebridementasneededtoremoveallnecrotictissue Amputationoftheextremitymaybenecessaryandlife saving Abdominalinvolvementrequiresexcisionofthebodywallmusculature Uterinegasgangrenefollowingsepticabortionusuallynecessitateshysterectomy AcquiredImmunodeficiencySyndrome AIDS AIDScontinuedtoincreaseasaresultofunsafesexualpracticesandinrecipientsofbloodproducts ClassificationsofAIDS Theinitialclinicalpresentationmayincludefever perspiration malaise myalgia arthralgia headache andsorethroat Gastrointestinalsymptoms lowabdominalcramping weightloss diarrhea tenesmus proctalgia andthebleeding Abnormalliverfunction OpportunisticinfectionincludePneumocystiscainii toxoplasmosis cryptosporidiosis isoporiasis andthefungalinfection Cytomegalovirus CMV infection Malignancy suchasKaposissarcomaandnon Hodgkin slymphoma GeneralPrinciplesOfTreatment Antibiotics PenicillinsCephalosporinsMonobactamsCarbapenemsQuinolonesAminoglycosides AntianaerobesMacrolidesTetracyclinesGlycopeptidesStreptograminsOxazolidinones Prophylacticsystemicantibioticsreduceinfectionwithclinicalbenefitinthefollowingcircumstances Prophylacticsystemicantibiotics High riskgastroduodenalproceduresHigh riskbiliaryproceduresResectionandanastomosisofthecolonorsmallintestine Cardiacproceduresthroughamediansternotomy Vascularsurgeryofthelowerextremitiesorabdominalaorta Amputationofanextremitywithimpairedbloodsupply particularlyinthepresenceofacurrentorrecentischemiculcer Vaginalorabdominalhysterectomy Primarycesareansection Operationsenteringtheoralpharyngealcavityincontinuitywithneckdissections Craniotomy Theimplantationofanypermanentprostheticmaterial Anywoundwithknowngrossbacterialcontamination Accidentalwoundswithheavycontaminationandtissuedamage Injuriespronetoclostridialinfection Inthepresenceofpreexistingvalvularheartdamage Useofantibiotic Formildinfections includingmostthatcanbehandledonanoutpatientbasis thismaybeachievablewithoralantibioticswhenappropriatechoicesareavailable Forseveresurgicalinfections however thesystemicresponsetoinfectionmaymakegastrointestinalabsorptionofantibioticsunpredictable Inaddition forintra abdominalinfections gastro intestinalfunctionisoftendirectlyimpaired Forthesereasons mostinitialantibiotictherapyforsurgicalinfectionsisbegunintravenously Ifobviousimprovementisnotseenwithin2to3days oneoftenhearsthequestion Whichantibioticshouldweadd switchto Followingquestionshouldbeaddressed Theinitialoperativeprocedurewasnotadequate Theinitialprocedurewasadequatebutacomplicationhasoccurred Asuperinfectionhasdevelopedatanewsite Thedrugchoiceiscorrect butnotenoughisbeinggiven Anotheroradifferentdrugisneeded Whentostopantibiotictherapy Areliableguidelineistocontinueantibioticsuntilthepatienthasshownanobviousclinicalimprovementbasedonclinicalexaminationandhashadanormaltemperaturefor48hoursormore Signsofimprovementincludeimprovedmentalstatus return