医学专业英语课件_3

CaseDiscussionHuangHonghuiDepartmentofHematologyRenJiHospitalCaseSummary26year-old,femalepatientpersistentnasalbleedingforoneday,haveanupperrespi-ratoryinfection2weekspreviously.Nofever,chills,nausea,vomiting,abdominalpain,orjointpain.PE:multiplel-mmreddishspotsonherlowerextremities.Nolymphadenopathyorhepatosplenomegaly.Noexcessivebleedingwithmenses,childbirth,priorepistaxis,easybruisability,orbleedingintoherjoints.Nofamilyhistoryofabnormalbleeding.Nottakeanymedication.ObjectsofAnalysisLearntheclinicalapproachtobleedingdisorders,specificlyplateletsdisordersversuscoagulationdisorders.Learnaboutthedifferentialdiagnosisofthrombocytopenia,specificallythrombocytopenicpurpuraversusotherplateletdisorders,suchasthromboticthrombocytopenicpurpura(TTP),hemolyticuremicsyndrome(HUS),ordisseminatedintravascularcoagulation(DIC).LearnaboutthetreatmentofITP.Considerationsuperficialpetechiaeandmucosalbleedingdisorderedprimarymaryhemostasislaboratorytesting•completebloodcount•prothrombintime(PT)screening•partialthromboplastintime(PTT)•BonemarrowsmearAPPROACHTOSUSPECTEDTHROMBOCYTOPENIAHISTORYLiverdisease,uremia,malignancy,systemiclupuserythematousMedications:over-the-counterproducts(aspirin)FamilyhistoryofabnormalbleedingHistoryofepistaxis,menorrhagia,excessiveprolongedbleedingfromminorcuts,bruising,prolongedorprofusebleedingafterdentalextraction,excessivebleedingaftermajorsurgeryorobstetricdelivery,traumafollowedbybleedingconsideredexcessiverelativetotheinjuryTimingofBleedingIfbleedingfollowingdentalextractionisimmediateandlastsforlongerthan24hours,aproblemwithprimaryhemostaticplugformationmaybepresent.Therefore,thismaysuggestaplateletdisorder.Ifinitialhemostasisseemednormalbutprolongedbleedingdeveloped2-3dayslater,aprobleminthecoagulationphaseissuspected.TypeofBleedingSpontaneousmucusmembranebleeding,suchasgumbleeding,nosebleeding,andpetechiaearesuggestiveofavasculardisorder,thrombocytopenia,orabnormalplateletfunction.Hemarthrosis,deephematoma,andretroperitonealbleedingaremorelikelytoreflectaseverecoagulationabnormality,•suchashemophilia,ifproblemshavebeenlifelong•spontaneousinhibitoroffactorVIII,ifproblemsappearlateriniife.VascularDisordersVascularpurpura•presentwithbleedingfrommucusmembranesandtheappearanceofpetechiae•butusuallytheplateletcountandthecoagulationprofile(PTandPTT)arenormalHereditaryhemorrhagictelangiectasias•inheritedasanautosomaltraitofhighpenetrance.•themostcommonhereditaryvasculardisorder•Thephysicalexamwillshowthepresenceoftelangiectasias.Causesofthrombocytopeniadecreasedplateletproductiondecreasedplateletsurvivalsequestration(hypersplenism)dilutionalSpuriousThrombocytopeniaAutomatedcellcountersreportsspuriousthrombocytopeniainapproximately0.l%ofpatients.Thisisgenerallyaresultofplateletdumpingafterdrawingbloodintotheanticoagulantethylenediaminetetraacetate(EDTA).Confirmation•Identifyingplateletaggregatesonperipheralbloodsmear•UsingcitrateorheparinasananticoagulantImpairedplateletproductionInfiltrationcausedbymalignancyormyelofibrosisMarrowhypoplasia•Chemicals•Drugs•Radiation•VirusesDecreaseplateletsurvivalimmunethrombocytopeniapurpua(causedbyIgGantibodyagainsttheplatelets),drug-inducedthrombocytopenicpurpurasecondaryimmunologicpurpura(asinlymphoma,lupus,infectionwithhumanimmunodeficiencyvirustype1)posttransfusionpurpura.DisseminatedintravascularcoagulationhemolyticuremicsyndromecavernoushemangiomaacuteinfectionsITPAcuteITP•earlychildhood•antecedentupperrespiratoryinfection•self-limiting,usuallyresolvesspontaneouslywithin3-6months.ChronicITP•inadults,mostlikelytooccurinwomenages20-40years•aninsidiousorsubacutepresent.•persistformonthstoYears,withuncommonspontaneousremission.SeveralimmunologicdisordersmaymimictrueITPdruginducedthrombocytopenicpurpura•Discontinuationofthemedicationshouldleadtoimprovementintheplateletcountwithinatimeframeconsistentwiththedrug’smetabolism.•Manydrugsareblowntocausethrombocytopenicpurpura,suchasquinidineandquinine,Sulfonamide,heparin,andgoldcompounds.SLELymphoma•Lymphadenopathy•splenomegalyHIV-1infectionPosttransfusionpurpuraNonimmunologicdisordersmaymimictrueITPDICTTPDICETIOLOGY•Secondarytosomeotherprocess:sepsis,trauma,metastaticmalignancy,obstetriccausesCLINICALCOURSE•canberelativelymildindolentcourse,orseverellfe-threateningprocess;•ongoingcoagulationandfibrinolysis;•cancausethrombosisorhemorrhage;•consumptionofcoagulationfactorsisseenasprolongedPTandPTTDICTREATMENT•Treatmentaimedatunderlyingcause.•Noprovenspecifictreatmentforthecoagulationproblem.•Ifclotting,consideranticoagulatewithheparin.•Ifbleeding,replacefactorsandfibrinogenwithfreshfrozenplasmaorcryoprecipitate.TTPETIOLOGY•Multiplecauses,manyseeminglytrivialdrugs/infectionleadtoendothelialinjuryandreleaseofvonWillebrandfactor,triggeringformationofmlcrovascularthrombi.CLINICALCOURSE•fever•alteredmentalstates•thrombocytopenia•Microangiopathichemolyticanemia•RenalfailureTTPTREATMENT•Plasmapheresis(removaloftheexcess/abnormalvWF),mostpatientsrecover•corticosteroidsITPE