Page 439 - TNFlipTest

Toronto Notes 2019 Other Conditions of the Large Intestine General Surgery and Thoracic Surgery GS37
■ surgical
◆ right colectomy + ileotransverse colonic anastomosis
• sigmoid
■ nonsurgical
◆ decompression by flexible sigmoidoscopy and insertion of rectal tube past obstruction
◆ subsequent elective surgery recommended (50-70% recurrence) ■ surgical
◆ surgical resection with or without primary anastomosis
◆ indications: strangulation, perforation, or unsuccessful endoscopic decompression
Toxic Megacolon
Pathogenesis
• extensionofinflammationintosmoothmusclelayercausingparalysis
• damagetomyentericplexusandelectrolyteabnormalitiesarenotconsistentlyfound
Etiology
• inflammatoryboweldisease(ulcerativecolitis>Crohn’sdisease)
• infectiouscolitis:bacterial(C.difficile,Salmonella,Shigella,andCampylobacter),viral
(cytomegalovirus), and parasitic (E. histolytica)
Clinical Features
• infectiouscolitisusuallypresentsfor>1wkbeforecolonicdilatation
• diarrhea±blood(suddenimprovementofdiarrheamaysignifyonsetofmegacolon)
• abdominaldistention,tenderness,±local/generalperitonealsigns(suggestsperforation)
• triggers:hypokalemia,constipatingagents(opioids,antidepressants,loperamide,andanticholinergics),
barium enema, and colonoscopy
Diagnostic Criteria
• musthavebothcolitisandsystemicmanifestationsfordiagnosis
• radiologicevidenceofdilatedcolon
• threeof:fever,HR>120,WBC>10.5,andanemia
• oneof:fluidandelectrolytedisturbances,hypotension,oralteredLOC
Investigations
• CBC(leukocytosiswithleftshift,andanemiafrombloodydiarrhea),electrolytes,elevatedCRP,and ESR
• metabolicalkalosis(volumecontractionandhypokalemia)andhypoalbuminemiaarelatefindings
• AXR:dilatedcolon>6cm(right>transverse>left),lossofhaustra
• CT:usefultoassessunderlyingdisease
Treatment
• NPO,NGT,stopconstipatingagents,correctfluidandelectrolyteabnormalities,andtransfusion • serial AXRs
• broad-spectrumantibiotics(reducesepsis,andanticipateperforation)
• aggressivetreatmentofunderlyingdisease(e.g.steroidsinIBD,andmetronidazoleforC.difficile) • indications for surgery (50% improve on medical management)
■ worsening or persisting toxicity or dilation after 48-72 h ■ severe hemorrhage, perforation
■ high lactate and WBC, especially for C. difficile
• procedure:subtotalcolectomy+endileostomy(maybetemporary,withsecondoperationfor re-anastomosis later)
Prognosis
• 25-30%mortality
Fistula
Definition
• abnormalcommunicationbetweentwoepithelializedsurfaces(e.g.enterocutaneous,colovesical, aortoenteric, and entero-enteric)
Etiology
• foreignobjecterosion(e.g.gallstone,graft)
• inflammatorystates(e.g.infection,IBD[Crohn’s>UC],anddiverticulardisease) • iatrogenic/surgery(e.g.post-operativeanastomoticleak,andradiation)
• congenital, trauma
• neoplastic
Use caution when giving antidiarrheal agents, especially with bloody diarrhea
Why Fistulae Stay Open
FRIENDO
Foreign body
Radiation
Infection
Epithelialization
Neoplasm
Distal obstruction (most common)
Others: increased flow; steroids (may inhibit closure, usually will not maintain fistula)