THE RED SECTION 1

see related editorial on page x

Beyond Low Flow: How I Manage Ischemic

Lawrence J. Brandt , MD, AGA-F, FASGE, MACG1 and Paul Feuerstadt , MD, FACG 2 , 3

Am J Gastroenterol advance online publication, 11 October 2016; doi: 10.1038/ajg.2016.456

THE BIG PICTURE WHAT ELSE COULD IT BE? Colon (CI) is a common disease diagnosed in 16–24% Patient history, serologic testing, imaging, and are of patients presenting to the hospital with acute lower gastrointes- used to diff erentiate CI from other diseases with similar pres- HOW I APPROACH IT tinal (1 ) and accounting for ~16–18 per 100,000 hospital entations. New-onset Crohn’s disease and are admissions ( 2,3 ). Indeed, it is the most common ischemic disorder unusual in the elderly and typically present with more chronic of the GI tract, and it and infectious colitis are the most common symptoms, weight loss, distal colon involvement, and colonic colitides seen in patients older than 65 years of age. Th erefore, CI that show signs of acute and chronic infl ammation. is important to keep in mind whenever you are consulted on an Infectious colitis is diff erentiated by history of recent travel or older person with bloody , diarrhea, rectal bleeding, or food intake that placed the patient at risk with stool culture and . We prefer the umbrella term “colon ischemia” examination for parasites potentially confi rming etiology. Escher- instead of “ischemic colitis” since an infl ammatory phase of CI is ichia coli O157:H7 should be tested for in patients with rectal not documented in all patients, and thus, CI is a more accurate bleeding, and is an infectious cause of CI. Colonic adenocarci- term. Th e main questions we ask ourselves when approaching noma and other potential obstructions, e.g., may a patient with possible CI are: i) What are the symptoms; ii) What provoke proximal CI and need to be excluded. Radiation else could it be; iii) Should computed tomography (CT) and/or should be suspected by history and has a characteristic spiraling colonoscopy be performed; iv) How sick is the patient; v) Are telangiectasia appearance. needed; vi) Does the patient need a surgeon?

SHOULD CT OR COLONOSCOPY BE PERFORMED? WHAT ARE THE SYMPTOMS? Distinguishing CI from other causes of pain, rectal bleeding, and It was classically taught that CI presents with mild-to-moderate diarrhea can be challenging. CT scan with intravenous contrast is abdominal pain, followed by rectal bleeding or bloody diarrhea. the best modality to detail the distribution and phase of disease Now, we know the presentation and behavior of CI depends on and provides important insight into its severity: portal venous gas the site of involvement and with ischemia isolated to the right side ( Figure 1 ), pneumatosis linearis (Figure 2), and indi- of the colon (IRCI), pain may be quite severe and predominate cate severely diseased colon. over rectal bleeding. In fact, patients with IRCI may not bleed at When the CT scan and clinical presentation leave the diagno- all. Th is is important because IRCI has a worse prognosis than sis in doubt, colonoscopy is performed. We prefer to insuffl ate the CI aff ecting any other segment of colon and demands close colon with carbon dioxide rather than room air to minimize the monitoring, exclusion of occlusive disease of the superior mes- reduction in colonic blood fl ow that results from elevation in intra- enteric artery (SMA), and, oft entimes, surgical therapy. When CI luminal pressure ( 5 ). Colonoscopy is the most useful test to diag- has any other distribution, even when the right side is part of a nose CI by providing direct observation of the mucosa, detailing multi-segment pattern, the clinical presentation is characterized disease distribution and enabling confi rmation (4 ). CI has a by bleeding overshadowing abdominal pain and usually has a range of fi ndings including erythema, ulceration, and subepithelial good prognosis. Th erefore, in all patients with severe right-sided hemorrhage ( 6 ), but and the “Single Stripe Sign,” a linear abdominal pain, IRCI should be included in the diff erential diag- ulceration along the longitudinal axis of the left colon, are the nosis. Bleeding with CI tends not to be severe and uncommonly only colonoscopic fi ndings that reliably diff erentiate CI from other has hemodynamic signifi cance or requires transfusion ( 4). diseases (Figures 3 and 4) (7 ).

1 Division of , Albert Einstein College of Medicine / Montefi ore Medical Center, Bronx , New York , USA ; 2 Gastroenterology Center of Connecticut, Hamden , Connecticut , USA ; 3 Division of Digestive Disease, Yale University School of Medicine, New Haven, Connecticut , USA . Correspondence: Lawrence J. Brandt, MD, AGA-F, FASGE, MACG, Montefi ore Medical Center, 111 East 210 Street , Bronx , New York 10467 , USA. E-mail: lbrandt@montefi ore.org

© 2016 by the American College of Gastroenterology The American Journal of GASTROENTEROLOGY HOW I APPROACH IT 2 Figure2 The major consideration segmental distribution isthe of ischemic the cellcountblood ( are severity to assess used 6 ). As noted above, a aciddehydrogenase,hemoglobin, lactic and sodium, white serum raise concern for poor-outcome. urea nitrogen, Blood severity,disease but to guidemanagement ( 6 ). or serology, imaging, and colonoscopy not only to determine When suspicion for physical we use CIis high, examination, HOWSICKISTHEPATIENT? Figure1 THE and smallboweldilationinapatientwithSMAobstruction. with severecolonischemia. American Journal American RED . . CTscanshowingpneumatosislinearisoftheascendingcolon CTscanshowingportalvenousgasinapatientwhopresented SECTION of

GASTROENTEROLOGY megacolon are at greatest for risk mortality ( 6 ). fulminant colitis, venous portal gas,pneumatosis or linearis, ( 9 ). Patients with an “acute” abdomen or fi CTscan compromise of would which mandate immediate intervention raphy (MRA),or mesenteric angiography SMA to assess patency, recommend CT-angiography (CTA), magneticresonance angiog- chemia ( 9 ). In of allcases IRCI we original the review CTand colon ( 8 may). IRCI also associated with be acute mesenteric is and/or colectomy than CIinvolving any other region of the process. Patients with IRCI are at greater for risk 30-day mortality tion alongthelongitudinalaxisofcolon. Figure3 associated with poor-outcome); moderate CI (e.g., suspected mild (e.g., typical symptoms of CIwith none of factors risk the guidesour management: severity CIas Disease we classify AREANTIBIOTICSNECESSARY? in apatientwithseverecolonischemiaafteraorticaneurysmsurgery. Figure4 . . Colonoscopicimageofthe“SingleStripeSign,”alinearulcera- Colonoscopicimageshowingmucosalnecrosis(e.g.,gangrene) www.nature.com/ajg nig of ndings sporin). (e.g., fl (e.g., metronidazole or clindamycin) with Gram negative coverage ate acombination we or use severe disease, of an anti-anaerobe bacteremia and improve outcome. In allpatients with moder- ofmodels acute occlusion vascular that show antibiotics minimize of CIand justifi are nostudies inhumans addressing antibiotics for treatment the “surgical abdomen”, we practice conservative management. Th distribution isother than IRCI, and patient the not does have a a combination of ischemia and . If disease the fl of hasresolved non-IRCI, and ischemic period the colon blood CI. Th colonicthe vasculature inpatients with an indexpresentation of mesenteric ischemia (AMI)are our only two reasons to image IRCI and failure to able be to clinically diff graphy, latter the having also therapeutic potential. Th branches; can done this be by CTA, MRA, or traditional angio- exclude potentially causative lesions obstructive of SMA the or its and image mesenteric the vasculaturewith surgical the service to are more aggressive with our therapy. If there isIRCI, we consult consultation, and image splanchnic the vasculature as assoon patientsthese to intensive the care unit, obtain immediate surgical tion with our interventional and surgical colleagues. We transfer above,measures described antimicrobial therapy, and consulta- Patients with “severe” DOESTHEPATIENT require disease same the conservative NEEDASURGEON? but weaft doso ofepisode CI,we donot typically evaluate for hypercoagulability, cations, immunomodulators, and illicit ( drugs) 6 ). Aft tinuing any associated with CI(e.g., -inducing medi- ofa key part our assessment and consideration ismadefor discon- causes are addressed. Comprehensive of review allmedications is trolytes, and optimizing cardiac status; any underlying possible measures including or CT).If patients have “mild” we treat disease, with conservative copy, or pan-colonic or distribution IRCI disease on colonoscopy matosis venous or linearis, portal gason CT, gangrene on colonos- >3 of factors risk the for peritoneal moderate signs, pneu- disease, sodium<136 mmol/l, cells>15×10 white blood >20 mg/dl, Hgb<12 g/dl, lactate dehydrogenase >350 U/l, serum dia, abdominal pain without bleeding, rectal urea blood nitrogen with © 2016by theAmericanCollege ofGastroenterology ow hasalready normalized. Clinic When apatient isclassifi is is because by isbecause timeof the clinical presentation incases 1 uoroquinolone, aminoglycoside, third generation cephalo- – 3 of following: the malegender, hypotension, tachycar- er multiple episodes. cation for isextrapolated use their from mouse nil peros ed ashaving “moderate” we disease, , intravenous fl al expression of CIrepresents erentiate CIfrom acute uids, balancing elec- 9 /l); or severe (e.g., epresence of erasingle ere REFERENCES Potential competing interests: Financial support paper. Brandt, Paul Feuerstadt. authors Both have read and approved the Specifi Guarantor of thearticle CONFLICTOFINTEREST and surgical consultation. warrantswho more aggressive intervention, including antibiotics we can should determine who receive conservative therapy and poor-outcome. By triaging patients according tovariables, these data,tory CT, and colonoscopic fi of process. the Attention to site the of involvement, basiclabora- is related to segment the of colon involved aswell severity asthe CI isacommon and usually b SUMMARY increases signifi in recognition of severe process, this of likelihood the mortality recognition important. isvery of If severe disease there isalag process Timelying iscrucial. prompt disease isof so essence, the possible. Identifi R patients of n outcomes a and Features m LJ . i Brandt r O , r Aroniadis P e , Feuerstadt M , C 9. h s a charac- k patient a patterns, r Anatomic P MC . Blaszka P , , Feuerstadt G LJ , Brandt n a m 8. r e k c u Z . 7 guideline: clinical ACG SJ . Boley GF , Longstreth P , Feuerstadt LJ , Brandt 6. E s i k a z t i a l a K , S n o s s d JS n Choi u KH, m Kahler u DC , Suh G , P 2. J n o s s n i e r H . 1 . Bad L oe S amrao Cro doie n ro air room and dioxide Carbon . R Sammartano SJ , Boley LJ , Brandt 5. MA Montoro 4. factors, high-risk features, clinical Epidemiology, JF . Yao GF , Longstreth 3. 2015;13:1962–8. or followed by acute mesenteric ischemia . Clin Gastroenterol Hepatol with ischemia isolated to right the sideof colon the accompanied when 2010;105:2245–52. Gastroenterol J Am histology . by supported teristics, and clinical outcomes inischemic colitis: astudy of 313cases 2003;98:2018–22. Gastroenterol J Am colitis . ischemic to relationship its 2015; 110:18–44. Gastroenterol J Am (CI). ischemia colon of ment epidemiology, factors, risk patterns of presentation, diagnosis,and manage- 1986;32:324–9. Endosc Gastrointest dog. the in pressure Th constipation have an for risk increased ischaemic colitis . Aliment Pharmacol 2013;25:37–43. Hepatol Gastroenterol J Eur bleeding: incidence, etiology, and outcomes inapopulation-based setting . insuffl 2011;46:236–. Gastroenterol J Scand study) . (CIE results of Working the Group for Study the of Ischaemic Colitis inSpain e1–2. 2009;7:1075–80, and outcome of acute large bowel ischemia . Clin Gastroenterol Hepatol er 2007 ; 25 : 681 – 92 . 2007;25:681–92. er c author contributions ation of colon. the Eff et al. cantly. cation and treatment of any contributing under- : None. : Clinical patterns and outcomes of ischaemic colitis: The : L.J. Brandt, MD, AGA-F, FASGE, MACG. ects onects colonic fl blood American Journal American et al. : Concept and writing: Lawrence J. None. Patients with or enign disease, althoughenign disease, prognosis ndings for risk minimizesthe et al. et al. Th THE ecolon single-stripesignand of Lwr gastrointestinal Lower

GASTROENTEROLOGY ow and intraluminal RED SECTION 3 HOW I APPROACH IT