2022年醫(yī)學(xué)專題-缺血性腸病

IschemicColitisRi陳宏彰第一頁(yè)，共三十頁(yè)。ReferencebooksHarrison’sonline15thMarx:Rosen'sEmergencyMedicine:ConceptsandClinicalPractice,5thed.,Copyright?2002Mosby,Inc第二頁(yè)，共三十頁(yè)。IschemicColitisIschemiaofthecolonmostoftenaffectstheelderly

(90%ofpatients>60y/o).Ischemiccolitisisalmostalways

nonocclusive.

(emboliarethemostcommoncauseofacutemesentericischemia)Shuntingofbloodawayfromthemucosa

maycontributetothiscondition,butthe

mechanismisunknown.第三頁(yè)，共三十頁(yè)。IschemicColitisMostpatientsischemiaoccurssecondarytoarteriolarshunting,

spasm,orpoorperfusionofmucosalvessels.Mostcasesinvolvethesplenicflexure,whichissuppliedbyend-arteries.Therectumisusuallyspared,becauseitsbloodsupplyisdifferentfromtherestofthecolonandlessdependent

ontheinferiormesentericartery.Marx:Rosen'sEmergencyMedicine:ConceptsandClinicalPractice,5thed

第四頁(yè)，共三十頁(yè)。TypesofIschemicColitisAcutefulminantischemiccolitis

Subacuteischemiccolitis

HARRISON’SONLINE15TH

第五頁(yè)，共三十頁(yè)。TypesofIschemicColitisGangrenousischemiccolitis

acompletelossofarterialflowcausesbowelwallinfarctionandgangrene,whichcanprogresstoperforation,peritonitis,anddeath.Stricturingischemiccolitis

agrossimpairmentofthearterialsupply,leadingtohemorrhagicinfarctionofthemucosa,whichulcerates,healsbyfibrosis,andfinallyleadstostenosis.Transientischemiccolitis

atransient,reversibleimpairmentofthearterialsupply,whichcausesapartialmucosalsloughthathealsbymucosalregenerationinafewdays.themostcommon

Marx:Rosen'sEmergencyMedicine:ConceptsandClinicalPractice,5thed

第六頁(yè)，共三十頁(yè)。Acutefulminantischemiccolitismanifestations

Theonsetischaracteristicallyacute,withgeneralizedlowerabdominalpain,usuallyintheleftlowerquadrant,followedwithin24hoursbybloodydiarrheaorrectalbleeding.Dilationofthecolonandphysicalsignsofperitonitisareseeninseverecases.Withthegangrenoustype,bothsymptomsandsignsprogressrapidly.

第七頁(yè)，共三十頁(yè)。AcutefulminantischemiccolitisDiagnosticStrategyNospecificserummarkersproveninthediagnosisofintestinalischemia.

Abdominalfilmsmayreveal

thumbprintingfromsubmucosalhemorrhageandedema.*(bariumenemaiscontraindicatedincasesofgangrenousischemic

colitis

becauseoftheriskofperforation)第八頁(yè)，共三十頁(yè)。thumbprinting

第九頁(yè)，共三十頁(yè)。AcutefulminantischemiccolitisDiagnosticStrategySigmoidoscopyorcolonoscopymaydetectulcerations,friability,andbulgingfoldsfromsubmucosalhemorrhage.(Colonoscopyispreferredoversigmoidoscopy

)Thesegmentaldistributionandrectalsparingofthediseaseprocessaresuggestivebutarenotdiagnostic.第十頁(yè)，共三十頁(yè)。Colonoscopicviewshowingmarkederythemaandexudateinsigmoidcolon

第十一頁(yè)，共三十頁(yè)。Endoscopicviewofmucosaledema,exudates,andulcerationsinsigmoidcolon

第十二頁(yè)，共三十頁(yè)。Endoscopicimageofdescendingcolonshowingseverecolitiswithpneumatosisintestinalis.

第十三頁(yè)，共三十頁(yè)。AcutefulminantischemiccolitisDiagnosticStrategyAngiographyisnothelpfulinthemanagementofpatientswithpresumedischemiccolitisbecausearemediableocclusivelesionisveryrarelyfound.

CTscanisnormalinearlystagesofbowelinfarction,althoughitmayshownonspecificfindingssuchasbowelwallthickeningandpneumatosis.

第十四頁(yè)，共三十頁(yè)。CTshowingleftsidedcolonicthickening.第十五頁(yè)，共三十頁(yè)。PneumatosisIntestinalis第十六頁(yè)，共三十頁(yè)。PneumatosisIntestinalis第十七頁(yè)，共三十頁(yè)。AcutefulminantischemiccolitismanagementWhenischemiccolitisissuspected,asurgeonshouldbeconsulted.Gangrenousischemiccolitisorevidenceofperforationrequiresimmediatesurgeryassoonasthepatientisstabilized.

第十八頁(yè)，共三十頁(yè)。managementVasopressorsshouldbeavoided,ifpossible.Lowblood-flowstates(hypotension)shouldbeaggressivelyreversed.第十九頁(yè)，共三十頁(yè)。TypesofIschemicColitisAcutefulminantischemiccolitis

Subacuteischemiccolitis

第二十頁(yè)，共三十頁(yè)。Subacuteischemiccolitis

manifestations

Itproduceslesserdegreesofpainandbleeding,oftenoccurringoverseveraldaysorweeks.

Theleftcolonmaybeinvolved,buttherectumisusuallysparedbecauseofthecollateralbloodsupply.第二十一頁(yè)，共三十頁(yè)。Subacuteischemiccolitis

managementSubacute

Ischemic

colitiswithoutevidenceofperitonitisorperforationisgenerallyself-limitedandrequiresonlyconservativemanagement,includingbowelrest,parenteralfluids,andantibiotics.第二十二頁(yè)，共三十頁(yè)。Subacuteischemiccolitis

management

Mostcasesofnonocclusiveischemiccolitisresolvein2to4weeksanddonotrecur.Surgeryisnotrequiredexceptforobstructionsecondarytopostischemicstricture.

第二十三頁(yè)，共三十頁(yè)。DifferentialConsiderationsIschemic

colitisoftenmimicsinfectiouscolitis,inflammatoryboweldisease,orevencoloncarcinoma.ManycasesofcolitisintheelderlyonceconsideredtobeCrohn’sdiseaseorulcerativecolitisinretrospectwerereallycolonicischemia.

第二十四頁(yè)，共三十頁(yè)。DifferentialConsiderationsThefeaturesconsideredatypicalininflammatoryboweldiseases,suchas1.segmentaldistributionofthedisease,infrequentrectalinvolvement,2.highrateofspontaneousrecovery,lowrateofrecurrence,3.lackofadequateresponsetousualinflammatoryboweldiseasetherapy,4.frequentprogressiontofibroticstenosiswithdelayedobstructionThefeaturesabovearenowrecognizedascharacteristicofcolonicischemia.

第二十五頁(yè)，共三十頁(yè)。DifferentialConsiderationsAlwaysconsiderthediagnosisofischemic

colitiswhenevercontemplatingthediagnosisofinflammatoryboweldiseaseinanelderlypatient.

第二十六頁(yè)，共三十頁(yè)。DifferentialDiagnosisClinical

Radiologic

UlcerativecolitisBloodydiarrheaExtendsproximallyfromrectum;finemucosalulcerationCrohn’scolitisPerianallesionscommon;frankbleedinglessfrequentthaninulcerativecolitisSegmentaldisease;rectalsparing;strictures,fi