title: Meta-analysis: the use of carbon dioxide insufflation vs. room air insufflation for gastrointestinal endoscopy.
abstract: BACKGROUND
  Carbon dioxide (CO(2)) insufflation has been proposed as an alternative to air insufflation to distend the lumen in gastrointestinal (GI) endoscopy.
  
  
  OBJECTIVE
  To perform a systematic review with meta-analysis of randomised controlled trials (RCTs) in which CO(2) insufflation was compared with room air insufflation in GI endoscopy.
  
  
  METHODS
  Electronic and manual searches were combined to search RCTs. After methodological quality assessment and data extraction, the efficacy and safety of CO(2) insufflation were systematically assessed.
  
  
  RESULTS
  Twenty-one RCTs [13 on colonoscopy, four on endoscopic retrograde cholangiopancreatography (ERCP), two on double-balloon enteroscopy (DBE), one on oesophagogastroduodenoscopy, and one on flexible sigmoidoscopy] were identified. For colonoscopy, CO(2) insufflation resulted lower postprocedural pain intensity, and increased the proportion of patient without pain at 1 h (RR: 1.84, 95% CI: 1.37-2.47) and 6 h (RR: 1.28; 95% CI: 1.14-1.44) postprocedure. For ERCP, the pain-releasing effect of CO(2) insufflation was not obvious (SMD: -1.48, 95% CI: -3.56, 0.59). CO(2) insufflation revealed no consistent advantages in the RCTs of DBE, but was shown as safe as air insufflation in oesophagus/stomach endoscopic submucosal dissection in one study. pCO(2) level showed no significant variation during these procedures.
  
  
  CONCLUSIONS
  Compared with air insufflation, CO(2) insufflation during colonoscopy causes lower postprocedural pain and bowel distension without significant pCO(2) variation. More RCTs are needed to assess its advantages in other GI endoscopic procedures.
authors.affiliation: Key Laboratory of Combined Multi-organ Transplantation, Ministry of Public Health, Hangzhou, China.
authors.forename: W L
authors.initials: WL
authors.lastname: Wang
authors.forename: Z H
authors.initials: ZH
authors.lastname: Wu
authors.forename: Q
authors.initials: Q
authors.lastname: Sun
authors.forename: J F
authors.initials: JF
authors.lastname: Wei
authors.forename: X F
authors.initials: XF
authors.lastname: Chen
authors.forename: D K
authors.initials: DK
authors.lastname: Zhou
authors.forename: L
authors.initials: L
authors.lastname: Zhou
authors.forename: H Y
authors.initials: HY
authors.lastname: Xie
authors.forename: S S
authors.initials: SS
authors.lastname: Zheng
mesh_terms: D000388:Air; D002245:Carbon Dioxide / Q000008:administration & dosage*; D016099:Endoscopy, Gastrointestinal / Q000379:methods*; D006801:Humans; D007327:Insufflation / Q000379:methods*; D010147:Pain Measurement; D010149:Postoperative Pain / Q000517:prevention & control*; D016032:Randomized Controlled Trials as Topic
chemical_list: D002245:Carbon Dioxide