Researchers from Porsgrunn and Oslo, Norway, assessed patient tolerance and safety when using carbon dioxide (CO2) insufflation during colonoscopy.
A series of 240 patients, referred for a baseline colonoscopy due to findings in a flexible sigmoidoscopy screening trial, were enrolled in the study.
All were randomly assigned to the use of either air (n = 119) or CO2 (n = 121) insufflation during colonoscopy, over an 8-month period.
End tidal CO2 (ETCO2), a non-invasive parameter of arterial pCO2, was registered before, and repeatedly during and after the examination.
The patient's experience of pain during and after the examination was registered using a visual analogue scale (VAS).
| Using CO2 insufflation did not raise arterial CO2 levels.
Sedation was not used routinely.
The groups were similar in age, sex, and cecal intubation rate.
No rise in ETCO2 was registered.
The authors found that the patients in the CO2 group reported significantly less pain than those in the air group.
Dr Michael Bretthauer, of the Norwegian Colorectal Cancer Prevention Center, Telemark Central Hospital, Porsgrunn, said on behalf of his colleagues, "This randomized study of unsedated patients shows that CO2 insufflation is safe during colonoscopy, with no rise in ETCO2 level.
"CO2 was found to be superior to air, in terms of pain experienced after the examination," he concluded.