The use of carbon dioxide for insufflation during GI endoscopy: a systematic review

Gastrointest Endosc. 2009 Apr;69(4):843-9. doi: 10.1016/j.gie.2008.05.067. Epub 2009 Jan 18.


Background: Insufflation of the lumen is required for visualization during GI endoscopy. Carbon dioxide (CO(2)) has been proposed as an alternative to room air for insufflation.

Objectives: To assess the safety and efficacy of CO(2) insufflation for endoscopy.

Design: Systematic review that focuses on evidence from randomized controlled trials (RCT).

Methods: Two investigators independently searched MEDLINE from 1950 to February 13, 2008, to identify all articles that reported the use of CO(2) in a GI endoscopy application. Bibliographies of relevant articles were also hand searched to identify other pertinent reports. Data from RCTs, as well as from nonrandomized studies, were extracted.

Results: Nine RCTs were identified that compared CO(2) and air insufflation for GI endoscopy. Fifteen other nonrandomized studies or reports were also reviewed. In the 8 RCTs in which postprocedural pain was assessed, pain was lower in the CO(2) insufflation group compared with the air group. Two RCTs found decreased flatus in the CO(2) group compared with the air group, and 3 RCTs showed there was decreased bowel distention on abdominal radiography in the CO(2) group compared with the air group. Also, in all 9 RCTs and 6 additional studies in which safety was assessed, there was no CO(2) retention and no adverse pulmonary events related to CO(2) insufflation.

Limitations: Because of study heterogeneity, meta-analytic techniques could not be used.

Conclusions: Consistent RCT evidence indicates that CO(2) insufflation is associated with decreased postprocedural pain, flatus, and bowel distention. CO(2) insufflation also appears to be safe in patients without severe underlying pulmonary disease.

Publication types

  • Research Support, N.I.H., Extramural
  • Review
  • Systematic Review

MeSH terms

  • Carbon Dioxide*
  • Endoscopy, Gastrointestinal / methods*
  • Humans
  • Insufflation*


  • Carbon Dioxide