缺血性肠病.ppt

IschemicColitisRi陳宏彰第一页，共三十页。ReferencebookslHarrisons online 15thlMarx:Rosens Emergency Medicine:Concepts and Clinical Practice,5th ed.,Copyright2002Mosby,Inc第二页，共三十页。IschemicColitislIschemiaofthecolonmostoftenaffectstheelderly(90%ofpatients60y/o).lIschemiccolitisisalmostalways nonocclusive.(emboli are the most common cause of acute mesenteric ischemia)lShunting of blood away from the mucosa maycontributetothiscondition,butthe mechanismisunknown.第三页，共三十页。IschemicColitislMostpatientsischemiaoccurssecondarytoarteriolar shunting,spasm,orpoor perfusionofmucosalvessels.lMostcasesinvolvethesplenic flexure,whichissuppliedbyend-arteries.lTherectum is usually spared,becauseitsbloodsupplyisdifferentfromtherestofthecolonandlessdependentontheinferiormesentericartery.Marx:RosensEmergencyMedicine:ConceptsandClinicalPractice,5thed第四页，共三十页。TypesofIschemicColitis1.Acute fulminant ischemic colitis2.Subacute ischemic colitisHARRISONSONLINE15TH第五页，共三十页。TypesofIschemicColitisGangrenous ischemic colitis a complete loss of arterial flow causes bowel wall infarction and gangrene,which can progress to perforation,peritonitis,and death.Stricturing ischemic colitis a gross impairment of the arterial supply,leading to hemorrhagic infarction of the mucosa,which ulcerates,heals by fibrosis,and finally leads to stenosis.Transient ischemic colitis a transient,reversible impairment of the arterial supply,which causes a partial mucosal slough that heals by mucosal regeneration in a few days.the most commonMarx:RosensEmergencyMedicine:ConceptsandClinicalPractice,5thed第六页，共三十页。Acute fulminant ischemic colitis manifestations 1.Theonsetischaracteristicallyacute,withgeneralized lower abdominal pain,usuallyintheleft lower quadrant,followedwithin24hoursbybloody diarrhea or rectal bleeding.2.Dilationofthecolonandphysicalsignsofperitonitisareseeninseverecases.3.Withthegangrenoustype,bothsymptomsandsignsprogressrapidly.第七页，共三十页。Acute fulminant ischemic colitis Diagnostic StrategylNospecificserummarkersproveninthediagnosisofintestinalischemia.lAbdominal filmsmayreveal thumbprintingfromsubmucosalhemorrhageandedema.*(bariumenemaiscontraindicatedincasesofgangrenousischemiccolitisbecauseoftheriskofperforation)第八页，共三十页。thumbprinting第九页，共三十页。Acute fulminant ischemic colitis Diagnostic StrategylSigmoidoscopyorcolonoscopymaydetectulcerations,friability,andbulgingfoldsfromsubmucosalhemorrhage.(Colonoscopyispreferredoversigmoidoscopy)lThesegmental distributionandrectal sparingofthediseaseprocessaresuggestivebutarenotdiagnostic.第十页，共三十页。Colonoscopicviewshowingmarkederythemaandexudateinsigmoidcolon第十一页，共三十页。Endoscopicviewofmucosaledema,exudates,andulcerationsinsigmoidcolon第十二页，共三十页。Endoscopicimageofdescendingcolonshowingseverecolitiswithpneumatosisintestinalis.第十三页，共三十页。Acute fulminant ischemic colitis Diagnostic StrategylAngiographyisnothelpfulinthemanagementofpatientswithpresumedischemiccolitisbecausearemediableocclusivelesionisveryrarelyfound.lCT scanisnormalinearlystagesofbowelinfarction,althoughitmayshownonspecificfindingssuchasbowelwallthickeningandpneumatosis.第十四页，共三十页。CTshowingleftsidedcolonicthickening.第十五页，共三十页。PneumatosisIntestinalis第十六页，共三十页。PneumatosisIntestinalis第十七页，共三十页。Acute fulminant ischemic colitis managementlWhenischemiccolitisissuspected,asurgeonshouldbeconsulted.lGangrenousischemiccolitisorevidenceofperforationrequiresimmediatesurgeryassoonasthepatientisstabilized.第十八页，共三十页。managementlVasopressorsshouldbeavoided,ifpossible.lLow blood-flow states(hypotension)shouldbeaggressivelyreversed.第十九页，共三十页。TypesofIschemicColitis1.Acute fulminant ischemic colitis2.Subacute ischemic colitis第二十页，共三十页。Subacute ischemic colitismanifestationslItproduceslesserdegreesofpainandbleeding,oftenoccurringoverseveraldaysorweeks.lTheleftcolonmaybeinvolved,buttherectumisusuallysparedbecauseofthecollateralbloodsupply.第二十一页，共三十页。Subacute ischemic colitismanagementlSubacute Ischemiccolitiswithoutevidenceofperitonitisorperforationisgenerallyself-limitedandrequiresonlyconservative management,includingbowelrest,parenteralfluids,andantibiotics.第二十二页，共三十页。Subacute ischemic colitismanagement lMostcasesofnonocclusiveischemiccolitisresolvein2to4weeksanddonotrecur.lSurgeryisnotrequiredexceptforobstructionsecondarytopostischemicstricture.第二十三页，共三十页。Differential ConsiderationslIschemiccolitisoftenmimicsinfectious colitis,inflammatory bowel disease,orevencoloncarcinoma.lManycasesofcolitisintheelderlyonceconsideredtobeCrohnsdiseaseorulcerativecolitisinretrospectwerereallycolonicischemia.第二十四页，共三十页。Differential ConsiderationslThefeaturesconsideredatypicalininflammatoryboweldiseases,suchas1.segmentaldistributionofthedisease,infrequentrectalinvolvement,2.highrateofspontaneousrecovery,lowrateofrecurrence,3.lackofadequateresponsetousualinflammatoryboweldiseasetherapy,4.frequentprogressiontofibroticstenosiswithdelayedobstructionlThefeaturesabovearenowrecognizedascharacteristicofcolonicischemia.第二十五页，共三十页。Differential ConsiderationslAlwaysconsiderthediagnosisofischemiccolitiswhenevercontemplatingthediagnosisofinflammatoryboweldiseaseinanelderlypatient.第二十六页，共三十页。DifferentialDiagnosisClinicalRadiologicUlcerativecolitisBloody diarrhea Extends proximally from rectum;fine mucosal ulceration CrohnscolitisPerianal lesions common;frank bleeding less frequent than in ulcerative colitisSegmental disease;rectal sparing;strictures,fissures,ulcers,fistulas;small bowel involvement IschemiccolitisOlder age groups;vascular disease;sudden onset,often painful Splenic flexure;“thumb printing”;rectal involvement rare 第二十七页，共三十页。ConclusionslAlwaysconsiderthediagnosisofischemiccolitiswhenevercontemplatingthediagnosisofinflammatoryboweldiseaseintheelderly.lThumbprintingofthecolononplainabdominalradiographssuggestsischemiccolitis.lSurgicalconsultationiswarrantedinallcasesofsuspectedischemiccolitis.第二十八页，共三十页。Thanxforyourattention第二十九页，共三十页。内容(nirng)总结Ischemic Colitis。Harrisons online 15th。HARRISONS ONLINE 15TH。Conclusions第三十页，共三十页。