ASGE指南急性结肠假性梗阻和结
AcuteColonicPseudo-Obstruction急性结肠假性梗阻
Etiologyandclinicalpresentation病因与临床表现
ACPO,synonymouswithOgilvie’ssyndrome,ischaracterizedbyanacutepresentationofmassivedilationofthelargeintestineintheabsenceofamechanicaletiology.Mostpatientsarehospitalizedatonset.Theexactpathogenesisremainstobeelucidated,butcurrentevidencesuggestsanalterationintheautonomicnervoussystemresultingincolonicatonyandpseudo-obstruction.SeveralriskfactorshavebeenidentifiedinthedevelopmentofACPO,includingcriticalillness,recentsurgicalprocedure,metabolicimbalance,andnonoperativetrauma.Althoughthetrueincidenceremainsunknown,inaretrospectivecohortstudyusinganationaladmissionsdatabase,theannualincidenceofACPOwasapproximatelycasesof,inpatientadmissionsperyear.
ACPO又称Ogilvie综合征，其特点是在没有机械病因的情况下，出现急性大肠显著扩张。大多数病人在发病时住院治疗。确切的发病机制尚待阐明，但目前证据表明，自主神经系统的改变导致了结肠无力和假性梗阻。在ACPO的发展过程中发现了一些危险因素，包括危重病、近期手术、代谢失衡和非手术创伤。虽然真实发病率仍然未知，一个回顾性队列研究使用一个国家住院数据库发现每年例住院病人中约有例ACPO患者。
Adverseevents不良事件
ThemostseriousadverseeventsofACPOareischemiaandperforation,withanincreasedriskfortheseadverseeventsinpatientswithcecaldiametersgreaterthan10to12cmandinthosewithdurationofdistentionexceeding6days.Atthetimeofcolonoscopy,approximately10%ofpatientshavesomedegreeofischemiaintheright-sidedcolon.Riskofspontaneousperforationisestimatedtobebetween3%and25%,withupto50%riskofmortalityintheeventofaperforation.
ACPO最严重的不良事件是缺血和穿孔，盲肠直径大于10-12cm和扩张时间超过6天的患者发生这些不良事件的风险增加。在结肠镜检查时，大约10%的患者在右侧结肠存在不同程度的缺血。自发性穿孔的风险估计在3%到25%之间，一旦穿孔，死亡率高达50%。
Imagingiscrucialinestablishingadiagnosisbecausemechanicalobstructionmustbeexcluded.Plain-filmabdominalradiographyisusuallysufficientinmakingadiagnosis,althoughitcannotalwaysreliablydistinguishmechanicalfromfunctionalcausesofobstruction.Water-solublecontrastenemaoftherectumanddistalcolonisanotherdiagnosticoption,althoughCThaslargelyreplacedcontrastenemastudies.Itisworthnotingthatmechanicalobstructionrarelyoccursinapatientadmittedforunrelatedillnesses(eg,pneumonia,electivenon-GIsurgery).
由于必须排除机械性梗阻，影像学检查对诊断至关重要。腹部平片通常足以作出诊断，尽管它不能总是可靠地区分机械性和功能性梗阻原因。尽管CT已经在很大程度上取代了造影剂灌肠，但是直肠和远端结肠的水溶性造影剂灌肠仍然是一种有效的诊断方法。值得注意的是，机械性梗阻很少发生在因无关疾病（如肺炎、择期非胃肠道手术）的入院患者身上。
保守治疗Conservativetherapy
Inpatientswithun
