Air and Carbon Dioxide Volumes Insufflated During Colonoscopy
Author(s) BRETTHAUER Michael ; HOFF Geir S. ; THIIS-EVENSEN Espen ; HUPPERTZ-HAUSS Gert ; SKOVLUND Eva ;
Author(s) Affiliation(s)
The Cancer Registry of Norway Institute for Population-Based Cancer Research, Oslo, NORVEGE
Norwegian Colorectal Cancer Prevention (NORCCAP) Center Department of Medicine, Telemark Hospital, Skien, NORVEGE
Department of Medicine, The Norwegian National Hospital, Oslo, NORVEGE
Section of Medical Statistics, University of Oslo, Oslo, NORVEGE
Abstract
Background: During colonoscopy, air or carbon dioxide is insufflated to secure adequate visualization of the colon, and endoscopy trainees are reminded to use as little gas as possible to avoid patient discomfort. The aim of the present study was to measure volumes of carbon dioxide and air insufflated during colonoscopy.
Methods: Consecutive patients participating in a colorectal cancer screening program were randomized to undergo colonoscopy with either carbon dioxide or air insufflation. Gas volumes insufflated during the procedure were measured with a mass-flowmeter. Four experienced endoscopists performed all of the examinations.
Results: Gas volumes were successfully measured in 218 patients. A mean of 8.3 L of carbon dioxide (range 1.2-19.8 L) and 8.2 L of air (range 1.8-18 L) were insufflated. Mean volumes insufflated per minute were estimated to be 0.26 L and 0.24 L, respectively, in the carbon dioxide and air groups.
Conclusions: The volumes of carbon dioxide and air used during colonoscopy can be estimated. Differences in volumes of gas used by experienced endoscopists were detected.
From Gastrointestinal Endoscopy – 2003, Vol 58, pages 203-206
I came across this Norwegian study in a Medical Journal. The patients were all part of a screening program for colorectal cancer. Usually such patients are sedated and given a muscle relaxant, but they would not have been subjected to intolerable discomfort. I have read that colonoscopies are sometimes unsatisfactory, because the walls of the colon has not been sufficiently distended. In this study, the average volumes used were just over 8 liters and the largest volumes used were 19.8 and 18 liters..
Can anyone explain why the four experienced endoscopists would need to inject such large volumes of CO2 or Air for successful colonoscopy examinations?