Carbon dioxide insufflation vs conventional air insufflation for colonoscopy: a systematic review and meta-analysis of published randomized controlled trials.
OBJECTIVE
Conventional air insufflation (AI) may cause prolonged abdominal bloating, excessive abdominal pain and discomfort during colonoscopy. Carbon dioxide may be an acceptable alternative to avoid these complications. The object of this study was to evaluate systematically the effectiveness of carbon dioxide insufflation (CI) for colonoscopy compared with AI.


METHODS
Randomized controlled trials (RCTs) comparing the effectiveness of CI with that of AI during colonoscopy were retrieved from medical electronic databases and combined analysis was performed using the RevMan statistical package. The combined outcome of dichotomous and continuous variables was expressed as an odds ratio (OR) and standardized mean difference (SMD).


RESULTS
Twenty-one RCTs comprising 3607 patients were included in the study. There was statistically significant heterogeneity among included studies. CI showed a significant trend towards reduced procedural pain [SMD -1.34; 95% confidence interval (95% CI) -2.23 to -0.45; z = 2.96; P < 0.003] and also postprocedural pain at 1 h (SMD -1.11; 95% CI -1.83 to -0.38; z = 2.97; P < 0.003), 6 and 24 h (OR 0.44; 95% CI 0.23-0.85; z = 2.44; P < 0.01). CI was associated with faster caecal intubation (SMD -0.20; 95% CI -0.37 to -0.02; z = 2.23; P < 0.03) but the caecal intubation rate was similar (P = 0.59) in both colonic insufflation techniques .


CONCLUSIONS
CI seems to have clinical advantages over AI for colonoscopy with regard to pain during and after the procedure.
Department of General, Endoscopic and Laparoscopic Colorectal Surgery, Western Sussex Hospitals NHS Trust, Worthing Hospital, Worthing, West Sussex.
M S
MS
Sajid
Department of General, Endoscopic and Laparoscopic Colorectal Surgery, Western Sussex Hospitals NHS Trust, Worthing Hospital, Worthing, West Sussex.
J
J
Caswell
Department of General and Colorectal Surgery, Queen Elizabeth Hospital, King's Lynn NHS Foundation Trust, King's Lynn, Norfolk, UK.
M I
MI
Bhatti
Department of General, Endoscopic and Laparoscopic Colorectal Surgery, Western Sussex Hospitals NHS Trust, Worthing Hospital, Worthing, West Sussex.
P
P
Sains
Department of General, Endoscopic and Laparoscopic Colorectal Surgery, Western Sussex Hospitals NHS Trust, Worthing Hospital, Worthing, West Sussex.
M K
MK
Baig
Department of General and Colorectal Surgery, Queen Elizabeth Hospital, King's Lynn NHS Foundation Trust, King's Lynn, Norfolk, UK.
W F A
WF
Miles
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000388:Air; D002245:Carbon Dioxide / Q000008:administration & dosage*; D002432:Cecum / Q000601:surgery; D003113:Colonoscopy / Q000379:methods*; D005260:Female; D006801:Humans; D007327:Insufflation / Q000009:adverse effects / Q000379:methods*; D007431:Intraoperative Complications / Q000453:epidemiology* / Q000209:etiology / Q000517:prevention & control; D008297:Male; D008875:Middle Aged; D010149:Postoperative Pain / Q000453:epidemiology* / Q000209:etiology / Q000517:prevention & control; D016032:Randomized Controlled Trials as Topic; D055815:Young Adult
D002245:Carbon Dioxide
Carbon dioxide; air; colonoscopy; distension; insufflation; pain