Ischemic Colitis


Clinical

  • History of stroke, hypotension, heart failure, diabetes, or abdominal radiation exposure.
  • Vomiting, and fever.
  • Elderly pt with Hx of Arrhythmia
  • hematochezia/melena (bloody diarrhea)
  • Diarrhea
  • abdominal tenderness
  • weight loss
  • abdominal bruit
  • vasculitis
  • light headedness, pallor, dyspnea
  • food fear (sitophobia)

Diagnostic Test

Test Finding
CBC eukocytosis, anemia, evidence of hemoconcentration
CMP Acidosis, uremia, elevated creatinine, amylasemia
arterial blood gas/lactate level acidosis, elevated lactate
ECG atrial fibrillation, arrhythmia, acute myocardial infarction
erect CXR free air if perforation present
abdominal x-rays air-fluid levels, bowel dilation, pneumatosis, bowel wall thickening with thumbprinting sign suggestive of submucosal edema or hemorrhage
sigmoidoscopy or colonoscopy mucosal sloughing or friability; mucosal petechiae; submucosal hemorrhagic nodules, erosions or ulcerations; submucosal edema; luminal narrowing; necrosis; gangrene
mesenteric angiography proximal defect of a mesenteric vessel or vasoconstriction of all mesenteric arcades
CT scan with contrast/CT angiogram bowel wall thickening, bowel dilation, pneumatosis intestinalis, portal venous gas, occlusion of the mesenteric vasculature, bowel wall thickening with thumbprinting sign suggestive of submucosal edema or hemorrhage
barium enema thumbprinting, edema, cobblestoning, stricture
mesenteric duplex ultrasound reduced or lack of blood flow through proximal mesenteric vessels
magnetic resonance angiograph (MRA) narrowing or obstruction of mesenteric vasculature; decreased bowel wall enhancement

Differential

Disease/Condition Differentiating Signs/Symptoms Differentiating Tests
Infectious colitis May have similar clinical features. -Colonoscopy will demonstrate if ischemia is present.
-Stool cultures may reveal causative organism.
-CT may show marked thickening of colon with Clostridium difficile.
Ulcerative colitis Form of inflammatory bowel disease that affects the rectum and extends proximally. Characterized by diffuse inflammation of the colonic mucosa and a relapsing, remitting course.

Patients commonly experience bloody diarrhea, chronic diarrhea (or both), lower abdominal pain, fecal urgency, and extraintestinal manifestations, particularly those related to activity of the colitis.

Diagnosis requires endoscopy with biopsy and negative stool culture.
Crohn disease Inflammatory bowel disease that may involve the entire gastrointestinal tract..

 Common presenting symptoms include chronic diarrhea, weight loss, and right lower quadrant abdominal pain mimicking acute appendicitis.
Diagnosis confirmed by colonoscopy with ileoscopy and tissue biopsy.
Diverticular disease Symptomatic disease may have similar clinical features to ischemic bowel disease. Fever common in diverticulitis; diarrhea common, usually no hematochezia. CT may demonstrate focal colonic thickening and evidence of diverticulosis and diverticulitis.
Large bowel obstruction Obstipation may be a symptom. In most instances, CT will demonstrate cause of obstruction, such as tumor, internal hernia or volvulus..
Peptic ulcer disease Pain is generally epigastric and less severe, but may be generalized abdominal discomfort. Nausea and vomiting are common. Usually symptoms are less acute. Esophagogastroduodenoscopy will demonstrate gastritis and ulcers.
Small bowel obstruction Often have a history of previous abdominal surgery. Nausea, vomiting, and abdominal distension are the predominant features. X-ray studies will show air-fluid levels and dilated small bowel. CT will show dilated proximal small bowel with distal decompression, with a possible transition point.
Acute pancreatitis May provide a history of gallstones or recent alcohol use. Pain usually focal at epigastrium and radiates to back. Usually no diarrhea or hematochezia. Elevated serum amylase and lipase (usually much higher than in bowel ischemia). Abdominal ultrasound and CT demonstrate pancreatic inflammation and may show related gall bladder pathology.
Gastroenteritis May have similar clinical features. Possible history of sick contacts. May have a significant component of nausea and vomiting. Pain is often less profound than in patients with ischemia. CT may demonstrate thickened loops of small bowel or mesenteric lymphadenopathy without evidence of ischemia or infarcti
 

Treatment

Patient Group Tx Line Treatment
evidence of infarction, perforation, or peritonitis 1st Resuscitation and supportive measures:
  • Initial measures include supplemental oxygen via a mask, correction of hypotension with fluids and inotropic support if required, assigning NPO status, inserting a nasogastric tube for decompression, and correction of any heart arrhythmias.
  • Monitoring should be appropriate for the clinical condition of the patient, which may include invasive monitoring
plus Empiric antibiotics
  • Antibiotics suitable for enteric coverage (e.g., third-generation cephalosporin or quinolone plus metronidazole) should be given to all patients, as bacterial translocation may be significant due to the loss of the normal intestinal mucosal barrier.

     
  • Ceftriaxone : 1 g intravenously every 24 hours
    or
    Levofloxacin : 500 mg intravenously every 24 hours
    -- AND --
    Metronidazole : 500 mg intravenously every 8 hours
plus Exploratory laparotomy or laparoscopy
  • The presence of infarction, perforation, or peritonitis warrants urgent exploratory laparotomy or laparoscopy.
  • The exact nature of the subsequent procedures will depend on preoperative investigations and intraoperative findings.
superior mesenteric artery (SMA) embolus plus Papaverine infusion + embolectomy or arterial bypass ± bowel resection
  • Responsible for approximately 50% of acute mesenteric ischemia events. Emboli typically originate from the heart and lodge at points of normal anatomic tapering, usually just distal to the origin of a major branch.
    If not amenable to embolectomy, arterial bypass may be required. An embolus in the superior SMA causes severe vasoconstriction of both the obstructed and unobstructed branches of the SMA. If not corrected promptly this vasoconstriction can become irreversible and persist following removal of the embolus.
    Consequently, a papaverine infusion is used preoperatively, intraoperatively, and postoperatively until there is no clinical or radiographic evidence of continuing vasoconstriction.
     
  • Papaverine: 30-60 mg/hour as an intra-arterial infusion for 24 hours followed by angiographic evaluation; infusion may be restarted for additional 24-hour periods followed by repeat angiograms until resolution of vasoconstriction and clinical signs and symptoms; infusions have been maintained for as long as 5 days
acute superior mesenteric artery (SMA) thrombosis plus papaverine infusion + arterial reconstruction or bypass ± bowel resection
  • The absence of collaterals on angiography suggests an acute SMA thrombosis has occurred and necessitates immediate intervention.
    Surgical procedures that may be used in these circumstances include antegrade and retrograde bypass grafting, aortic reimplantation of the superior mesenteric artery, and transarterial and transaortic mesenteric endarterectomy. 
  • Papaverine infusions are continued before, during and after surgery until there is no more angiographic or clinical evidence of persistent vasoconstriction.
     
  • papaverine: 30-60 mg/hour as an intra-arterial infusion for 24 hours followed by angiographic evaluation; infusion may be restarted for additional 24-hour periods followed by repeat angiograms until resolution of vasoconstriction and clinical signs and symptoms; infusions have been maintained for as long as 5 days
plus Postoperative heparinization
  • Timing of postoperative heparinization is controversial, although it is generally recognized as being beneficial.
  • Some authorities recommend a delay of 48 hours because of the risk of intraluminal bleeding from damaged bowel, while others advocate immediate heparinization. Another suggested approach has been immediate anticoagulation if no infarction was present, but delayed anticoagulation if intestinal infarction was present. Good data supporting any of these approaches are lacking. 

     
  • heparin : see local protocol for dosing guidelines
nonocclusive mesenteric ischemia plus Papaverine infusion ± bowel resection
  • Responsible for 20% to 30% of cases of acute mesenteric ischemia and results from mesenteric vasoconstriction following hypoperfusion of the gut. Hypoperfusion may be precipitated by congestive heart failure, cardiac arrhythmia, shock, or by large volume shifts such as occur during hemodialysis.
    Papaverine infusion should be continued before, during and after surgery until there is no angiographic or clinical evidence of persistent vasoconstriction.
    Bowel of questionable viability should be preserved unless necrosis is clear; borderline viable bowel often responds to papaverine and, by using frequent re-explorations, intestinal resection can be kept to a minimum.
     
  • Papaverine: 30-60 mg/hour as an intra-arterial infusion for 24 hours followed by angiographic evaluation; infusion may be restarted for additional 24-hour periods followed by repeat angiograms until resolution of vasoconstriction and clinical signs and symptoms; infusions have been maintained for as long as 5 days
mesenteric vein thrombosis plus Venous thrombectomy ± bowel resection
  • The presence of infarction, perforation or peritonitis mandates exploratory laparotomy.
  • If surgically feasible, venous thrombectomy can be considered.
  • Ideally, thrombectomy should be done prior to resection of any bowel as borderline ischemic bowel may recover following the procedure.
plus Anticoagulation
  • Whether or not a thrombectomy is undertaken, anticoagulation with heparin should be used routinely following surgery in patients with mesenteric vein thrombosis. Immediate heparinization for 7 to 10 days has been shown to decrease thrombus recurrence and progression, and to improve survival. In patients who receive heparin the recurrence rate is lowered from 25% to 13% and mortality is reduced from 50% to 13%. [20] Once patients are stable, and able to tolerate oral medication, they can be converted to warfarin, which should then be administered for 3 to 6 months.
     
  • heparin : see local protocol for dosing guidelines
  • warfarin : see local protocol for dosing guidelines
adjunct Papaverine infusion
  • Papaverine may be infused into the superior mesenteric artery to relieve any associated arterial spasm that may be contributing to the ischemic injury.

     
  • papaverine: 30-60 mg/hour as an intra-arterial infusion for 24 hours followed by angiographic evaluation; infusion may be restarted for additional 24-hour periods followed by repeat angiograms until resolution of vasoconstriction and clinical signs and symptoms; infusions have been maintained for as long as 5 days
Fulminant ischemic colitis plus subtotal or total colectomy
  • These patients usually appear toxic and are unresponsive to medical therapy.
  • Ischemia and necrosis of the right-side colon can be treated by right hemicolectomy with primary anastomosis. If there is perforation and peritonitis, resection with terminal ileostomy and a colonic mucocutaneous fistula would be indicated.
  • Left-sided colonic involvement may require a proximal stoma and distal mucous fistula or Hartmann procedure.
  • If most of the colon and rectum are involved in the ischemia, total colectomy with terminal ileostomy is indicated.
  • Depending on the findings of the initial surgery, a second-look operation within 12 to 24 hours to reassess bowel viability may be indicated.
no evidence of infarction, perforation, or peritonitis 1st supportive measures
  • General measures should include bowel rest; nasogastric tube decompression; NPO status; intravenous fluids; supplemental oxygen; and correction of hypotension, heart failure, and arrhythmias.
  • Diligent and repeated reassessment of vital signs, physical exam, and laboratory values is required to detect failure of nonsurgical management that may then require operative intervention. These patients require close observation, and surgery is indicated should signs of peritonitis develop (e.g., rigid, distended abdomen, guarding and rebound, loss of bowel sounds).
plus Empiric antibiotics
  • Patients with colonic ischemia routinely receive antibiotic therapy suitable for enteric coverage to protect against bacterial translocation, although good evidence of benefit is lacking. The practice is based on a number of old studies and the theoretical protection it gives against the bacterial translocation that occurs with loss of mucosal integrity.

     
  • ceftriaxone : 1 g intravenously every 24 hours 
    or
    levofloxacin : 500 mg intravenously every 24 hours
    -- AND --
    metronidazole : 500 mg intravenously every 8 hours
superior mesenteric artery (SMA) embolus plus Papaverine infusion ± thrombolysis
  • Embolus in the SMA induces profound vasoconstriction of both the obstructed and unobstructed branches of the SMA. Such vasoconstriction can become irreversible and persist if not corrected promptly with a papaverine infusion.
    If there are no other contraindications, consideration can be given to concomitant local thrombolytic therapy. The most suitable cases are those where the embolus is a minor one (i.e., distal to the origin of the ileocolic artery), when there is only partial occlusion, and when it is given within 12 hours of the onset of symptoms.
  • If there is no evidence of lysis of the embolus within 4 hours or the patient develops evidence of worsening ischemia, exploratory laparotomy should be performed with a view to conventional surgical embolectomy.

     
  • papaverine: 30-60 mg/hour as an intra-arterial infusion for 24 hours followed by angiographic evaluation; infusion may be restarted for additional 24-hour periods followed by repeat angiograms until resolution of vasoconstriction and clinical signs and symptoms; infusions have been maintained for as long as 5 days
superior mesenteric artery (SMA) thrombosis plus Heparinization
  • Patients will generally be maintained on an intravenous heparin infusion once a diagnosis of SMA thrombosis is established.
    A heparin infusion titrated to therapeutic dosing following PTT prolongation to 1.5 to 2.5 times normal PTT levels is recommended.

     
  • heparin : see local protocol for dosing guidelines
plus Papaverine infusion + revascularization by percutaneous transluminal mesenteric angioplasty (PTMA)
  • In this circumstance it is reasonable to attempt revascularization by PTMA plus stenting, although it is a technically challenging procedure.A papaverine infusion is continued before, during and after the procedure until there is no more angiographic or clinical evidence of persistent vasoconstriction.

     
  • Papaverine: 30-60 mg/hour as an intra-arterial infusion for 24 hours followed by angiographic evaluation; infusion may be restarted for additional 24-hour periods followed by repeat angiograms until resolution of vasoconstriction and clinical signs and symptoms; infusions have been maintained for as long as 5 days
nonocclusive mesenteric ischemia plus Papaverine infusion + observation
  • Responsible for 20% to 30% of cases of acute mesenteric ischemia and results from mesenteric vasoconstriction following hypoperfusion of the gut.
    Hypoperfusion may be precipitated by congestive heart failure, cardiac arrhythmia, shock, or by large volume shifts such as occur during hemodialysis.
    Papaverine infusion should be continued until there is no angiographic or clinical evidence of persistent vasoconstriction.

     
  • papaverine: 30-60 mg/hour as an intra-arterial infusion for 24 hours followed by angiographic evaluation; infusion may be restarted for additional 24-hour periods followed by repeat angiograms until resolution of vasoconstriction and clinical signs and symptoms; infusions have been maintained for as long as 5 days
mesenteric vein thrombosis plus Anticoagulation + observation
  • In patients who have evidence of a mesenteric vein thrombus on CT scan, but do not have signs of infarction, perforation or peritonitis, immediate anticoagulation with heparin and a period of observation is appropriate. These patients need close clinical observation, and surgery is indicated if signs of peritonitis develop. If patients remain stable and symptom free, they may be converted to warfarin for 3 to 6 months.
  • If a mesenteric vein thrombus is discovered incidentally in an asymptomatic patient who undergoes a CT scan for another reason besides abdominal pain, then a 3- to 6-month course of warfarin is reasonable, especially if a predisposing hypercoagulable state or concomitant DVT can be identified.

     
  • heparin : see local protocol for dosing guidelines
  • warfarin : see local protocol for dosing guidelines
vasculitis associated mesenteric ischemia plus Corticosteroid therapy
  • If vasculitis is identified as a contributory cause of the ischemia (e.g., by thickened blood vessels on CT scan, the presence of other vasculitic symptoms, or a previous diagnosis), postoperative corticosteroid therapy may be considered.


    Methylprednisolone : 40-500 mg/day intravenously given in 1 to 4 divided doses
 

Admit Orders: Colitis/Diarrhea

1. Admit to:

2. Diagnosis: Colitis (Ischemnic ?)

3. Condition:

4. Vital Signs: q6h; call physician if BP >160/90, <80/60; P >120; R>25; T >38.5°C.

5. Activity: Up ad lib.

6. Nursing: Daily weights, inputs and outputs.

7. Diet: NPO. Advance to clear liquids as tolerated.

8. IV Fluids: 0.5-2 L NS over 1-2 hr then, D5 ½ NS at 125 cc/hr. NG tube at low intermittent suction (if obstructed).

9. Special Medications:

Inpatient Regimen:

-Metronidazole (Flagyl) 500 mg q8h IV/PO
AND

Ciprofloxacin (Cipro) 400 mg IV/PO q12h [STOP if C.Diff Positive]
OR

-Amoxicillin-clavulanate (Augmentin) 875/125 mg twice daily.
 

Outpatient Regimen:

-Metronidazole (Flagyl) 500 mg PO q6h
AND

Ciprofloxacin (Cipro) 400 mg PO bid.  [STOP if C.Diff Positive]
 

10. Symptomatic Medications:

 - Morphine sulfate 5-10 mg IV push prn pain.
 - Zolpidem (Ambien) 5-10 mg qhs PO prn insomnia.
 - Zofran 4mg IV q4-6h prn
 -Acetaminophen (Tylenol) 650 mg 2 tab PO/PR q4-6h prn temp >38°C or pain.
 -Docusate sodium (Colace) 100 mg PO qhs.
 -Famotidine (Pepcid) 20 mg IV/PO q12h.
 -Heparin 5000 U SQ q12h or pneumatic compression stockings
 

11. Extras: Acute abdomen series, CXR PA and LAT, ECG, CT of abdomen w/ PO & IV Contrast, ultrasound, surgery and GI consults.

12. Labs: CBC with differential, CMP, amylase, lipase, blood cultures x 2, drug levels peak and trough 3rd dose. UA, urine C&S. Stool WBC, culture for enteric pathogens, ova and parasites x 3, clostridium difficile toxin.

 

ITE 2013, Q91.
A 70-year-old alcoholic male is recovering from a myocardial infarction. On the fourth hospital day he complains of a sudden onset of excruciating abdominal pain that is not significantly reduced by large doses of morphine. He becomes nauseated, begins to vomit, and has diarrhea. The patient appears agitated and confused, and his heart rate increases. He also becomes hypotensive. Physical examination of his abdomen reveals minimal tenderness, decreased bowel sounds, and a moderately enlarged liver.
Laboratory Findings
WBCs 17,600/mm3 with a left shift (N 4300–10,800)
BUN 40 mg/dL (N 8–25)
Creatinine 1.0 mg/dL (N 0.6–1.5)
Serum lipase 150 U/L (N 0–160)
Arterial pH 7.14 (N 7.35–7.45)

The most likely diagnosis is:

A) alcohol withdrawal syndrome
B) pulmonary embolus
C) pancreatitis
D) acute mesenteric artery embolism
E) perforated gastric ulcer

ANSWER: D

 

Source: Epocrates, Tintinalli ED 7