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1、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. (em
2、boli 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.lMostcasesinvolvethespl
3、enic flexure,whichissuppliedbyend-arteries.lTherectum is usually spared,becauseitsbloodsupplyisdifferentfromtherestofthecolonandlessdependentontheinferiormesentericartery.Marx:RosensEmergencyMedicine:ConceptsandClinicalPractice,5thed第四页，共三十页。TypesofIschemicColitis1.Acute fulminant ischemic colitis2.
4、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 arteria
5、l 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.
6、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.D
7、ilationofthecolonandphysicalsignsofperitonitisareseeninseverecases.3.Withthegangrenoustype,bothsymptomsandsignsprogressrapidly.第七页，共三十页。Acute fulminant ischemic colitis Diagnostic StrategylNospecificserummarkersproveninthediagnosisofintestinalischemia.lAbdominal filmsmayreveal thumbprintingfromsubmu
8、cosalhemorrhageandedema.*(bariumenemaiscontraindicatedincasesofgangrenousischemiccolitisbecauseoftheriskofperforation)第八页，共三十页。thumbprinting第九页，共三十页。Acute fulminant ischemic colitis Diagnostic StrategylSigmoidoscopyorcolonoscopymaydetectulcerations,friability,andbulgingfoldsfromsubmucosalhemorrhage.
9、(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。Endoscop
10、icimageofdescendingcolonshowingseverecolitiswithpneumatosisintestinalis.第十三页，共三十页。Acute fulminant ischemic colitis Diagnostic StrategylAngiographyisnothelpfulinthemanagementofpatientswithpresumedischemiccolitisbecausearemediableocclusivelesionisveryrarelyfound.lCT scanisnormalinearlystagesofbowelinf
11、arction,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,asurgeonshouldbecon
12、sulted.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 colit
13、is2.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
14、 Ischemiccolitiswithoutevidenceofperitonitisorperforationisgenerallyself-limitedandrequiresonlyconservative management,includingbowelrest,parenteralfluids,andantibiotics.第二十二页，共三十页。Subacute ischemic colitismanagement lMostcasesofnonocclusiveischemiccolitisresolvein2to4weeksanddonotrecur.lSurgeryisno
15、trequiredexceptforobstructionsecondarytopostischemicstricture.第二十三页，共三十页。Differential ConsiderationslIschemiccolitisoftenmimicsinfectious colitis, inflammatory bowel disease,orevencoloncarcinoma.lManycasesofcolitisintheelderlyonceconsideredtobeCrohnsdiseaseorulcerativecolitisinretrospectwerereallyco
16、lonicischemia.第二十四页，共三十页。Differential ConsiderationslThefeaturesconsideredatypicalininflammatoryboweldiseases,suchas1.segmentaldistributionofthedisease,infrequentrectalinvolvement,2.highrateofspontaneousrecovery,lowrateofrecurrence,3.lackofadequateresponsetousualinflammatoryboweldiseasetherapy,4.fre
17、quentprogressiontofibroticstenosiswithdelayedobstructionlThefeaturesabovearenowrecognizedascharacteristicofcolonicischemia.第二十五页，共三十页。Differential ConsiderationslAlwaysconsiderthediagnosisofischemiccolitiswhenevercontemplatingthediagnosisofinflammatoryboweldiseaseinanelderlypatient.第二十六页，共三十页。Differ
18、entialDiagnosisClinicalRadiologicUlcerativecolitisBloody 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 bowe
19、l 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。
