What induces colitis? Hydrogen peroxide or peracetic acid

We have read the article of Cammarota et al. with great interest [1]. They analyzed a recent and underestimated disinfection complication. The authors suggested that colitis is due to hydrogen peroxide [1]. Coton et al. suggested that acute colitis is directly induced by peracetic acid [2]. In France, we use peracetic acid with acetic acid to wash endoscopes. The constituents of peracetic acid are hydrogen peroxide and acetic acid. As a concentrate, it is corrosive and irritating to the digestive tract. By releasing free oxygen and hydroxyl radicals, peracetic acid decomposes into oxygen, water, and acetic acid [3]. Peracetic acid and hydrogen peroxide are corrosive if not thoroughly rinsed from the endoscope [4]. Inadequate rinsing of endoscopic channels and surfaces with water after immersion in peracetic acid, may result in colitis, presumably caused by direct irritation of the mucosa.

This related colitis might be underestimated in endoscopic centers. In our center we recently diagnosed an iatrogenic colitis during screening colonoscopy in a 67-year-old woman. Colonoscopy with chromoendoscopy was performed using 2 % indigo carmine dye and a high resolution endoscope with ZOOM (Fujinon N°EC-590ZW). The indigo carmine dye was released into the colon through a special channel in this endoscope. Immediately after, a modification of the mucosa was observed ([Fig. 1]). “The snow white sign” appeared as mucosal whitening with a normal pit pattern of the mucosa ([Fig. 2]). The exam was stopped immediately. The patient experienced mild abdominal pain, which resolved within 48 hours. Another colonoscopy performed 2 weeks later was normal.

Fig. 1 The “snow white sign” of the mucosa.

Fig. 2 Endoscopic zoom of the “snow white sign” shows normal mucosa.

The injury was caused by inadequate rinsing of the channel designed for injecting the dye. The nurse did not have full knowledge of the cleaning process. During the disinfection phase, it is recommended to use peracetic acid, taking into account the particular epidemiological situation and the risk of prion disease transmission. In our case, colitis development coincided with the use of a specific chromoendoscopy channel, suggesting that it was due to inadequate rinsing. Cleaning endoscopes prior to chemical exposure involves purging the air/water channel, using enzymatic detergent solutions to clean the outside of the instrument, and brushing all valves and accessible channels. Special attention should be given to ensure that the peracetic acid and hydrogen peroxide are completely rinsed off the surface and irrigated through the channels of the colonoscope, especially the chromoendoscopy channel, which may have been missed in our case. Nurse education and adequate rinsing of specific channels may prevent the occurrence of related colitis.

Competing interests: None

References

• 1 Cammarota G, Cesaro P, Cazzato A. et al . Hydrogen peroxide-related colitis (previously known as “pseudolipomatosis”): a series of cases occurring in an epidemic pattern.  Endoscopy. 2007;  39 916-919
• 2 Coton T, Bohand X, Guisset M. et al . Acute colitis induced by a peracetic acid based solution used to disinfect endoscopes.  Gastroenterologie Clin Biol. 2003;  27 556-558
• 3 Cleaning and disinfection of equipment for gastrointestinal endoscopy. Report of a Working Party of the British Society of Gastroenterology Endoscopy Committee.  Gut. 1998;  42 585-593
• 4 Guidelines for the use of high-level disinfectants and sterilants for reprocessing of flexible gastrointestinal endoscopes.  Gastroenterol Nursing. 2000;  23 180-187