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

Background

Insufflation of the lumen is required for visualization during GI endoscopy. Carbon dioxide (CO₂) has been proposed as an alternative to room air for insufflation.

Objectives

To assess the safety and efficacy of CO₂ 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 CO₂ 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 CO₂ 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 CO₂ insufflation group compared with the air group. Two RCTs found decreased flatus in the CO₂ group compared with the air group, and 3 RCTs showed there was decreased bowel distention on abdominal radiography in the CO₂ group compared with the air group. Also, in all 9 RCTs and 6 additional studies in which safety was assessed, there was no CO₂ retention and no adverse pulmonary events related to CO₂ insufflation.

Limitations

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

Conclusions

Consistent RCT evidence indicates that CO₂ insufflation is associated with decreased postprocedural pain, flatus, and bowel distention. CO₂ insufflation also appears to be safe in patients without severe underlying pulmonary disease.

Abbreviations: CO₂, carbon dioxide, DBE, double-balloon enteroscopy, ETCO₂, End-tidal carbon-dioxide level, pCO₂, partial pressure of carbon dioxide, RCT, randomized controlled trial