Brief Article
Copyright ©2012 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Gastroenterol. Jul 7, 2012; 18(25): 3250-3253
Published online Jul 7, 2012. doi: 10.3748/wjg.v18.i25.3250
Carbon dioxide insufflation during colonoscopy in deeply sedated patients
Rajvinder Singh, Eu Nice Neo, Nazree Nordeen, Ganesananthan Shanmuganathan, Angelie Ashby, Sharon Drummond, Garry Nind, Elizabeth Murphy, Andrew Luck, Graeme Tucker, William Tam
Rajvinder Singh, Nazree Nordeen, Angelie Ashby, Sharon Drummond, Garry Nind, William Tam, Division of Gastroenterology, Department of Medicine, Lyell McEwin Hospital, South Australia 5070, Australia
Rajvinder Singh, William Tam, Department of Medicine, University of Adelaide, South Australia 5070, Australia
Eu Nice Neo, Elizabeth Murphy, Andrew Luck, Colorectal Unit, Department of Surgery, Lyell McEwin Hospital, South Australia 5070, Australia
Ganesananthan Shanmuganathan, Pantai Hospital, Kuala Lumpur 50000, Malaysia
Graeme Tucker, Health Statistics Unit, South Australia Health Center, South Australia 5000, Australia
Author contributions: Singh R conceptualized the study, conducted the procedures, analyzed the data and wrote the paper; Neo EN and Nordeen N wrote the paper; Shanmuganathan G edited the paper; Ashby A was the clinical research coordinator; Drummond S assisted in data collection; Nind G, Murphy E and Luck A conducted the procedures; Tucker G analyzed the data; Tam W conducted the procedures.
Correspondence to: Dr. Rajvinder Singh, MBBS, MRCP, MPhil, FRACP, AM FRCP, Senior Consultant Gastroenterologist, Division of Gastroenterology, Department of Medicine, Lyell McEwin Hospital, South Australia 5070, Australia.
Telephone: +61-8-81829000 Fax: +61-8-81829837
Received: October 29, 2011
Revised: May 7, 2012
Accepted: May 26, 2012
Published online: July 7, 2012

AIM: To compare the impact of carbon dioxide (CO2) and air insufflation on patient tolerance/safety in deeply sedated patients undergoing colonoscopy.

METHODS: Patients referred for colonoscopy were randomized to receive either CO2 or air insufflation during the procedure. Both the colonoscopist and patient were blinded to the type of gas used. During the procedure, insertion and withdrawal times, caecal intubation rates, total sedation given and capnography readings were recorded. The level of sedation and magnitude of patient discomfort during the procedure was assessed by a nurse using a visual analogue scale (VAS) (0-3). Patients then graded their level of discomfort and abdominal bloating using a similar VAS. Complications during and after the procedure were recorded.

RESULTS: A total of 142 patients were randomized with 72 in the air arm and 70 in the CO2 arm. Mean age between the two study groups were similar. Insertion time to the caecum was quicker in the CO2 group at 7.3 min vs 9.9 min with air (P = 0.0083). The average withdrawal times were not significantly different between the two groups. Caecal intubation rates were 94.4% and 100% in the air and CO2 groups respectively (P = 0.012). The level of discomfort assessed by the nurse was 0.69 (air) and 0.39 (CO2) (P = 0.0155) and by the patient 0.82 (air) and 0.46 (CO2) (P = 0.0228). The level of abdominal bloating was 0.97 (air) and 0.36 (CO2) (P = 0.001). Capnography readings trended to be higher in the CO2 group at the commencement, caecal intubation, and conclusion of the procedure, even though this was not significantly different when compared to readings obtained during air insufflation. There were no complications in both arms.

CONCLUSION: CO2 insufflation during colonoscopy is more efficacious than air, allowing quicker and better cecal intubation rates. Abdominal discomfort and bloating were significantly less with CO2 insufflation.

Keywords: Colonoscopy, Carbon dioxide, Air, Insufflations, Patient tolerance, Safety, Efficacy