-抗生素课件(英文)Antibiotic-Senior-Academic-Half-

AntibioticSeniorAcademicHalfDayMattRogers&JamesClaytonConsultantMicrobiologistsFebruary2011ObjectivesofthesessionBytheendofthesessionyouwillbeableto:DescribethefactorsthatneedtoconsideredwhenmakingthechoicetoprescribeanantibioticDevelopanunderstandingofkeypathogensandtheirsusceptibilitytoantibiotics.YouwillbeabletorelatethistotheantibioticpolicywithinyourTrustDefinewhatismeantbythetermAntibioticstewardshipBeawareofkeyDOHguidelines(Clostridiumdifficile)thatdirectthedevelopmentofantibioticpoliciesNametheantibioticsassociatedwithClostridiumdifficileStatetheminimumrequirementsofhowtoprescribeanantibioticNamethekeyissuesaroundrouteanddurationofantibioticsandhowthisaffectspatientsAntibioticstewardshipEnsurestheoptimisationofantibioticuseOnlyusewhennecessaryControlwhouseswhatControlrouteanddurationRespondtochangingneedsRespondtochangingEvidence/PoliciesRobustpolicing,reviewandstopstrategiesEprescribingAbitofbackground

ApottedhistoryofAntibioticsTheuseofantimicrobialsinthetreatmentofinfectionisoneofthetriumphsofmodernmedicine.

HistoryofAntibioticsBeforethediscoveryofthesulphurdrugsin1932,treatmentofinfectiousdiseasewaslimitedtomercury,arsenic,andquinine.Penicillinwasdiscoveredin1929.AlexanderFlemingHistoryofAntibioticsPenicillinwasnotmanufacturedonalargescalefornon-militaryuseuntil1949.

HistoryofAntibioticsDecadeAntibiotics1940s&1950sStreptomycinSyntheticpenicillinsCephalosporinsChloramphenicolTetracyclines.1960sQuinolones2000sOxazolidinone(Linezolid®)Glycylcycline(Tigecycline®)2010s??Longactingglycopeptides–phase3trialsResistancealwaysdevelopsExamplesStaphylococcusaureusPenicillinresistance1950/60sMRSA-Meticillinresistancesince1970sVRSA-Vancomycinresistancein2001EnterococciVRE:VancomycinResistantEnterococciColiformsQuinoloneresistanceESBLs:ExtendedSpectrumBeta-lactamasesMetalloBeta-lactamases

(NDM-1)AntimicrobialstewardshipAntimicrobialresistanceMultipleresistancegenesPlasmidsSpreadFactorsleadingtoresistance:InappropriateclinicaluseofABxPoorinfectioncontrolExcessiveABxuseinnonclinicalsettings:animalhusbandryshippingKeyantibioticchangesStopuseofcefuroximethroughouttheTrustUselowerriskaugmentin(butmonitorC.difficilerates)Reduceuseofciprofloxacin(considerpenicillinallergy)AntibioticpolicyavailableunderClinicalGuidelinesontheintranetAntibioticguidelinecreditcardsdistributedAntibioticstewardshipEnsurestheoptimisationofantibioticuseOnlyusewhennecessaryControlwhouseswhatControlrouteanddurationRespondtochangingneedsRespondtochangingEvidence/PoliciesRobustpolicing,reviewandstopstrategiesEprescribingAntibioticprescribing

What’simportant?WhenIsthereaninfection?HowTodiagnose.Whatspecimens?WhyWhatistheindication/Likelypathogens?WhatWhatantibiotic/route/durationWhen?DiagnosinginfectionisaCLINICALskillBasicsignsandsymptomsofinfectionPleaserememberapartfromsterilesites(urine/csf/bloodetc)mostareasyoucultureWILLgrowbacteriaWhennottoCSU-urinecloudy?ChestinfectionwithnoevidenceonCXRWoundwithserousexudateSloughyUlcersIsolatedspikesoftempTotreatahighWCCHow?HowtodiagnoseInfection???Whatspecimensdoyouneedtotake?Whatinvestigationsdoyouneedtoaskfor?Why?WhyarewegivingAntibioticsEmpirical/Prophylactic/TargetedKnowyourbasicMicrobiologyTheindication(UTI/LRTIetc)Thesetting(Pt+environment)HospitalvCommunity(feasibility)Thelikelypathogens(CRRS)ProphylaxisTherapygiventopreventaninfectionOftengivenaroundsurgeryGiventopatientspronetoparticularinfectionsContactsofNeisseriameningitidismeningitisGiventopatientswhoarespecificallyimmunocompromisedSplenectomyPCPprophylaxisinHIVSurgicalprophylaxisUsedtobegivenforseveraldaysEvidencenowsuggeststhatperi-operativeantibioticsadequateformost‘clean’operationsPrinciplesofantibioticprophylaxisTheuseofantibioticprophylaxisinvolvesadilemma;itishighlyeffectiveinpreventinginfection,butcanpromoteresistance.

Limittothoseindividualsinwhomtheriskofinfectionishigh.PrinciplesofantibioticprophylaxisWhichantibiotics?shouldbetargetedtothemostlikelypathogens.When?administrationasnearthetimeofincisionaspossible.Intravenousantibioticsshouldbegivenduringtheinductionofanaesthesiawithrepeatdosesforlongerprocedures.

Duration:keeptoaminimum(ofteneventoasingle-dose)toreducethechanceofresistancedeveloping.

Thebenefitsofpost-operativeprophylaxislastingmorethan12hhavenotbeenproven.IndicationsforantibioticprophylaxisContaminatedordirtyoperationspresenceofbowelcontents,pus,orinfectedforeignmaterialInsertionofgraftorprosthesiswheredevelopmentofinfectionwouldbeserious.ImmunocompromisedpatientsPatientswithcardiovascularabnormalities,mayrequirespecificantibioticprophylaxistoreducetheriskofendocarditis

(NICEguidelines,BSACguidelines)

RiskFactorsfor

SurgicalSiteInfectionPatient:ExtremesofagePoornutritionalstateObesityDiabetesmellitusSmokingCo-existinginfectionsatothersitesBacterialcolonisation(e.g.MRSA)ImmunosuppressionProlongedpostoperativestayOperationLengthofsurgicalscrubSkinantisepsisPreoperativeshavingPreoperativeskinprepLengthofoperationAntimicrobialprophylaxisOperatingtheatreventilationInadequateinstrumentsterilisationForeignmaterialinsurgicalsiteSurgicaldrainsSurgicaltechniqueincludinghaemostasis,poorclosure,tissuetraumaPostoperativehypothermiaSIGN:

ScottishIntercollegiateGuidelinesNetworkwww.sign.ac.uk

www.sign.ac.uk/guidelines/fulltext/104/index.html

SIGNqrg104.pdfEmpiricaltherapyTherapygivenwithoutknowingthecausativeorganismChoicebasedonpracticalexperienceandevidencebasedmedicine‘Bestguesstherapy’,unlikelytocoverallpossibilitiesTargetedtherapyTherapygivenwhentheinfectionandcausativeorganismisknownThisisthebestwayofeffectivetreatmentWeshouldknowtheactualsensitivityoftheoffendingpathogenWhat-ConsiderationsintherapyChoiceofagentincludes:RecentDOHguidance(Clostridiumdifficile)–HasalteredpoliciesRangeofpathogens(Why?)Infectionsite/drugpenetrationPatientfactors(allergy)TheaboveshouldbecoveredbyyourantibioticpolicyCombinationtherapy(synergy/antagonism)Dose/FrequencyRoute–IV/oralIV/oralswitchDuration(5-7daysformostinfection)PatientfactorsAllergyOthermedications(interactions)CantheytakePOToleranceComplianceInfectionsiteDrugpenetratione.g.Antibioticsaren’talwaystheanswerInfectionprostheses-SURGERYBone/SofttissueinfectionsSomedrugsliketheaminoglycosidesdonotpenetratewellMeningitisManydrugswillnotpenetrateCSFwellIVororalWhataretheconsiderationsDependsonsiteofinfectionOralbioavailabilityoftheantibioticClearaim/endpoint(treatment/suppression)LicencingMAUAudit

ZoeCampbellF2SHOOnlythosewithSeverepneumoniaaccordingtoCURBcriteriashouldreceiveIVantibiotics18outof25patientsreceivedIVantibiotics18patientswereclassifiedmild/mod(?Oralantibiotics)7patientswereclassifiedsevere(?IVantibiotics)I.V.Oral

Mild/ModerateSevereMAUAudit:IV/OralSwitchOnly2outof25(8%)patientshadanIVtooralswitch