Toxic Megacolon Treatment & Management

Treatment of toxic megacolon (toxic colitis) includes 3 main goals: (1) reduce colonic distention to prevent perforation, (2) correct fluid and electrolyte disturbances, and (3) treat toxemia and precipitating factors. Careful and frequent monitoring of the patient is required, and, initially, CBC counts, electrolytes, and abdominal radiographs should be checked every 12 hours.

• During the initial resuscitation, fluid replacement, electrolyte repletion, and transfusion should be aggressive. Broad-spectrum intravenous antibiotics with coverage equivalent to ampicillin, gentamicin, and metronidazole should be initiated. All medications that may affect colonic motility must be stopped. These include narcotics, antidiarrheals, and anticholinergic agents. The patient with toxic megacolon (toxic colitis) should be put on bowel rest, and a nasogastric tube (NGT) or long intestinal tube should be placed to assist with gastrointestinal decompression. Long suction tubes may be more helpful for colonic decompression, but they should be placed into the ileum under fluoroscopic guidance.
• The patient should be started on intravenous steroids. Intravenous hydrocortisone is necessary for patients who are taking corticosteroids or who have been recently treated with corticosteroids.
• It is important to recognize that, although symptomatic improvement may correspond to improvement in the disease process, this is not always the case. Cessation of bowel movements may indicate worsening of the patient's condition. Including repeated abdominal plain films in the evaluation of the clinical picture remains essential.
• Any possible triggers of toxic megacolon (toxic colitis) should be stopped, including narcotics, antidiarrheals, and anticholinergics. Rolling techniques (knee-elbow and prone) may be performed to assist in redistribution of colonic gas and decompression.^{[17, 18]}
• If the patient is malnourished, consider parenteral nutrition.
• Some reports indicate that cyclosporin A may be beneficial in the treatment of severe ulcerative colitis or toxic megacolon (toxic colitis). Data suggest that cyclosporin may provide an initial response rate of as high as 80%. After a variable follow-up period, the durable response rate decreases to approximately 40%. Cyclosporin does have significant adverse effects, including immunosuppression and opportunistic infections, hypertension, renal toxicity, and neurologic complications. Although further studies are needed, cyclosporin therapy may obviate the need for an urgent colectomy, such that an elective subtotal colectomy or proctocolectomy may be performed under more controlled circumstances.^[19]
• Some experimental therapies under study may help patients with toxic megacolon (toxic colitis) to avoid surgery. A case report showed that the use of infliximab, an anti-tumor necrosis factor (TNF)-alpha monoclonal antibody, was successful in the treatment of toxic megacolon (toxic colitis) in a patient whose condition failed to respond to usual treatment and who refused surgery.^[20]
• Leukocytapheresis (LCAP) has been reported in the treatment of toxic megacolon (toxic colitis). A series of 6 patients whose conditions had failed to improve after treatment with antibiotics and high-dose steroids were enrolled in the study.^[21] In 4 cases, the toxic megacolon (toxic colitis) resolved by the morning after initiation of treatment with LCAP. In 2 patients, the toxic megacolon (toxic colitis) resolved approximately 40 hours later. Improvement continued in 4 of the 6 patients.^[21]
• Hyperbaric oxygen has also been reported to be of use in the treatment of toxic megacolon (toxic colitis).^[22] Further studies are needed to confirm these results.
• Shetler et al demonstrated that colonoscopic decompression and intracolonic vancomycin administration in the management of severe, acute, pseudomembranous colitis associated with ileus and toxic megacolon (toxic colitis) is feasible, safe, and effective in approximately 57% to 71% of cases.^[23]

Early surgical consultation is essential for cases of toxic megacolon (toxic colitis). Indications for urgent operative intervention include free perforation, massive hemorrhage (6-8 U packed red blood cells), increasing toxicity, and progression of colonic dilatation. Most authors recommend colectomy if persistent dilatation is present or if no improvement is observed on maximal medical therapy after 24-72 hours.

The rationale for early intervention is based on a 5-fold increase in mortality after free perforation (the mortality rate of nonperforated acute toxic colitis is about 4%; if perforation occurs, the mortality is approximately 20%). Some physicians provide up to 7 days of medical therapy if the patient demonstrates clinical improvement despite persistent colonic dilatation. The authors recommend a strategy of early surgical intervention to minimize the incidence of colonic perforation.

• If no improvement occurs over 48-72 hours with medical therapy, perform surgical resection.

  • This strategy minimizes the incidence of colonic perforation. Perforation increases the chances of mortality from toxic megacolon (toxic colitis) by 5-fold.
  • Whether to perform a total proctocolectomy or subtotal colectomy with the rectum left behind is debated.^{[24, 25]} The preference in the literature is to perform a subtotal colectomy, because (1) the patient is usually very ill, and not lengthening the operation is prudent if at all possible; (2) it preserves the possibility for an ileal pouch anal anastomosis; and (3) approximately 50% of patients with Crohn disease have minimal involvement of the rectum. Performance of a total proctocolectomy in a patient who is acutely ill and toxic and on high-dose steroids would increase the risk of complications, morbidity, and likely mortality.
  • Terminate the resection at the sacral promontory, and perform either a mucus fistula or a stapled rectal stump. If a stapled rectal stump is performed, keeping a rectal tube in place for 2-3 days may reduce the incidence of rectal stump blowout.

• Consultation with a gastroenterologist and surgeon is required in cases of toxic megacolon (toxic colitis).
• Depending on the healthcare setting, other consultations that may be needed include a nutritionist and an infectious disease specialist.

• Patients with toxic megacolon (toxic colitis) should be at complete bowel rest.
• Parenteral nutrition should be considered in patients with toxic megacolon (toxic colitis).

• Patients with toxic megacolon (toxic colitis) should primarily be at bed rest. As previously mentioned, position changes, such as the prone position and the knee-elbow position, should be used to aid in colonic gas redistribution (see Treatment, Medical Care).