Ischemic and Infectious Colitis

Emily Finlayson, MD, MSUCSF Post Graduate Course in

General SurgeryMarch 23, 2011

Ischemic Colitis• Most common form of intestinal

ischemia– Lowest blood flow in GI tract– Relies on collateral flow– Does not autoregulate well

• Often occurs in hospitalized patients

• High index of suspicion

ELDER K et al. Cleveland Clinic Journal of Medicine, 2009.

Etiology• Idiopathic• Vascular occlusion

– Embolus, thrombosis– Hypercoagulable state– Surgery

• Systemic vascular disorders• Low flow (CHF, sepsis, hypovolemia)• Obstruction, impaction, volvulus• Medications

– Diurestics, beta-blockers, cocaine

Classification

Non-gangrenous (80%-85%)

Gangenous (15%-20%)

Chronic, nonreversible

Transient, reversible

Chronic colitis (20%-25%)

Stricture (10%-15%)

Presentation• Most patient over 60• Non-gangrenous

– Abdominal pain, diarrhea, hematochezia– Low grade fever– Heme + stool– Moderate WBC elevation with left shift

• Full thickness gangrene– Sepsis and shock

Diagnosis• Abdominal XR

– Free air, air in bowel wall, portal venous gas

• CT– Often non-specific thickening

Diagnosis• Abdominal XR

– Free air, air in bowel wall, portal venous gas

• CT– Often non-specific thickening

• NO barium enema!!

Diagnosis• Endoscopy

– Low pressure– Helpful in evaluating severity

Mild active colitis

Ulcer

Hemorrhagic Nodules

Diagnosis• Endoscopy

– Low pressure– Helpful in evaluating severity

• Angiography NOT helpful

Management

ELDER K et al. Cleveland Clinic Journal of Medicine, 2009.

Infectious Colitis• Pseudomembranous colitis

– Associated with virtually all antibiotics• Higher incidence

– Cephalosporins– Penicillins– Clindamycin

• Lower incidence– Aminoglycosides– Quinolones

• You only need one dose• Yes…even Flagyl

Pseudomembranous Colitis• Asymptomatic carriers

– 1%-3% general population– 20%-40% hospitalized adults– 50% long term care facilities

• Spores can survive weeks to month• On your stethoscope, for example

Pseudomembranous Colitis• Pathophysiology

– Toxins (A&B) bind to intestinal receptors– Inflammation and diarrhea

• New virulent strain• NAP1/BI/07• Previously uncommon, now epidemic• Severe disease in low risk patients

Pseudomembranous Colitis• High risk groups

– Drugs• Antibiotics• PPI• Valacyclovir

– IBD – Serious acute illness– GI procedures– Advanced age– Immunosuppressed– Post-partum (91% received antibiotic)

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Pseudomembranous Colitis• Other risk factors

– Drugs• Antibiotics• PPI (RR 4.17)• Valacyclovir

– Prolonged hospital stay– Hypoalbuminemia– Low levels of anti-toxin and B antibodies

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Differential Diagnosis• Ulcerative colitis

– History, endoscopy• Crohn’s disease

– History, endoscopy• Ischemic colitis

– More bleeding, risk factors, endoscopy• Amebic dysentery

– Bloody diarrhea, travel history, stool micro

Diagnosis• History

• Enzyme immunoassay for toxin A&B– 73% sensitivity, 98% specificity

• Endoscopy?– Assay negative but high suspicion– Need diagnosis before assay done– Failure of initial medical therapy

Initial Medical TherapyStool C Diff x 3 for Toxin A, B

Observe if mild symptoms Begin therapy prior to results if disease mod/severe

C Diff +

Endoscopy for diagnosis Continue therapy

C Diff -

Initial Medical TherapyAssess disease severity

Mild/moderate Severe

Vancomycin 125 mg QID + Flagyl

Flagyl 5oo mg TID for 10-14 days or vancomycin if epidemic

What is Severe Disease?• Organ failure• WBC > 15K• Cr > 2.3 mg/L• Hypoalbuminemia• Pancolitis on imaging• Megacolon• Risk groups

– Elderly, multimorbid, immunocompromised

Start Heading to the OR• WBC >= 20• Lactate >=5• Age >=75• Immunosuppression• Shock, vasopressors• Toxic megacolon• MOSF

Surgical Therapy• 3%-20% of cases become toxic

• 25-67% mortality– Delay in diagnosis and treatment

• Subtotal colectomy with ileostomy