Carbon Dioxide Insufflation in Colonoscopy Is Safe: A Prospective Trial of 347 Patients

Available evidence suggests that the use of CO2 insufflation in endoscopy is more comfortable for the patient. The safety of CO2 use in colonoscopy remains contentious, particularly in sedated patients. The objective of the present prospective trial was to assess the safety of CO2 colonoscopies. Methods. 109 patients from our previous randomized CO2 colonoscopy study and an additional 238 subsequent consecutive unselected patients who had a routine colonoscopy performed in a private practice were enrolled from April 2008 through September 2008. All but 2 patients were sedated. All patients were routinely monitored with transcutaneous CO2 measurement. Volumes of CO2 administered were correlated with capnographic measurements from transcutaneous monitoring. Results. Of the 347 patients examined, 57% were women; mean (SD) age of participants was of 60.2 years (12.8). Mean propofol dosage was 136 mg (64 mg). Mean CO2 values were 34.7 mm Hg (5.3) at baseline, 38.9 mm Hg (5.5) upon reaching the ileum, and 36.9 mm Hg (5.0) at examination's end. Mean maximum increase of CO2 was 4.5 mm Hg (3.6). No correlation was observed between volume of CO2 administered and increase in level of CO2 (correlation coefficient: 0.01; P value: 0.84). No complications were observed. Conclusions. The present prospective study, which was based on one of the largest sedated patient sample reported to date in this setting, provides compelling evidence that CO2 insufflation in colonoscopy is safe and unassociated with relevant increases in transcutaneously measured levels of CO2.