GuidelineComplications of colonoscopy
Section snippets
Cardiopulmonary complications
Cardiovascular and pulmonary complications related to sedation are reviewed in detail in the 2008 American Society for Gastrointestinal Endoscopy Guideline for Sedation and Anesthesia in GI Endoscopy.10 Intraprocedural cardiopulmonary complications have been variably defined to include events of unclear clinical significance, such as minor fluctuations in oxygen saturation or heart rate, to significant complications including respiratory arrest, cardiac arrhythmias, myocardial infarction, and
Perforation
Colonic perforation during colonoscopy may result from mechanical forces against the bowel wall, barotrauma, or as a direct result of therapeutic procedures. Early symptoms of perforation include persistent abdominal pain and abdominal distention. Later, patients may develop peritonitis. Plain radiographs of the chest and abdomen may demonstrate free air, although CT scans have been shown to be superior to the upright chest film.18 Therefore, an abdominal CT scan should be considered for
Hemorrhage
Hemorrhage is most often associated with polypectomy, although it can occur during diagnostic colonoscopy. When associated with polypectomy, hemorrhage may occur immediately or can be delayed for several weeks after the procedure.25 A number of large studies have reported hemorrhage in 1 to 6 per 1000 colonoscopies (0.1%-0.6%).2 A study analyzing over 50,000 colonoscopies by using Medicare claims found that the rate of GI hemorrhage was significantly different with or without polypectomy: 2.1
Postpolypectomy electrocoagulation syndrome
Postpolypectomy electrocoagulation syndrome is the result of electrocoagulation injury to the bowel wall that induces a transmural burn and localized peritonitis without evidence of perforation on radiographic studies. The reported incidence of this complication varies widely from 3 per 100,000 (0.003%) to 1 in 1000 (0.1%).2
Typically, patients with postpolypectomy electrocoagulation syndrome present 1 to 5 days after colonoscopy with fever, localized abdominal pain, localized peritoneal signs,
Mortality
Death has been rarely reported in relation to colonoscopy, with or without polypectomy. In a 2010 review of colonoscopy complications based on prospective studies and retrospective analyses of large clinical or administrative databases, there were 128 deaths reported among 371,099 colonoscopies, for an unweighted pooled death rate of 0.03%.2 All studies reported mortality within 30 days of the colonoscopy, although some reported all-cause mortality whereas others limited their analysis to
Infection
Transient bacteremia after colonoscopy, with or with polypectomy, occurs in approximately 4% of procedures, with a range of 0% to 25%.57 However, signs or symptoms of infection are rare.57 Although individual cases of infection after colonoscopy have been reported, there is no definite causal link with the endoscopic procedure and no proven benefit for antibiotic prophylaxis.58 Therefore, current guidelines from the American Heart Association and ASGE recommend against antibiotic prophylaxis
Gas explosion
Explosive complications of colonoscopy are rare, but they have serious consequences. A 2007 review reported 9 cases, each resulting in colonic perforation and, in one case, death.63 Gas explosion can occur when combustible levels of hydrogen or methane gas are present in the colonic lumen, oxygen is present, and electrosurgical energy is used (eg, electrocautery or argon plasma coagulation). Suspected risk factors are use of nonabsorbable or incompletely absorbable carbohydrate preparations,
Abdominal pain or discomfort
Less severe, but more common, sequelae of colonoscopy are also important and can impact patient adherence to future colonoscopy.2 The most commonly reported minor complications of colonoscopy are bloating (25%)68 and abdominal pain and/or discomfort 5% to 11%.68, 69, 70 Appropriate techniques, such as avoiding and reducing endoscope looping and minimizing air insufflation should help reduce these symptoms.71 In addition, randomized trials have demonstrated less postprocedure pain with carbon
Miscellaneous complications
Miscellaneous complications of colonoscopy include splenic rupture,80, 81 acute appendicitis,82 diverticulitis,2 subcutaneous emphysema,83, 84 and tearing of mesenteric vessels with intraabdominal hemorrhage. Chemical colitis may occur if glutaraldehyde, used during disinfection, has not been adequately rinsed from the endoscope.85
Colonoscopic tattooing
When a lesion requires marking to aid localization for surgical removal or endoscopic follow-up, a permanent dye is injected to tattoo the colon adjacent to the lesion.86 Use of sterile and appropriately diluted solutions has a low rate (0.2%) of complications.87
Colonic dilation
Colonic dilation has been used to treat benign strictures at surgical anastomoses and those associated with Crohn's disease.88 Two prospective studies with a total of 42 patients with anastomotic strictures not from Crohn's disease
Conclusion
Complications are inherent in the performance of colonoscopy. As endoscopy assumes a more therapeutic role in the management of GI disorders, the potential for complications will likely increase. Knowledge of potential endoscopic complications, their expected frequency, and the risk factors associated with their occurrence may help to minimize the incidence of complications. Endoscopists are expected to carefully select patients for the appropriate intervention, be familiar with the planned
Disclosure
D. Fisher is a consultant for Epigenomics. P. Malpas is a consultant for Olympus America. J. Dominitz is a consultant for Epigenomics and Salix Pharmaceuticals. B. Cash is a consultant for Salix Pharmaceuticals, J. Evans is a consultant for Cook Medical. G. Decker is a consultant for Facet Biotechnology. No other financial relationships relevant to this publication were disclosed.
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