Objective: Randomized placebo-controlled trials on the effectiveness of glucagon in colonoscopy were conducted more than a decade ago and the outcomes varied for each study. Since then, techniques and imaging technology in colonoscopy have steadily improved. The aim of this study was to re-evaluate the effectiveness of glucagon as an antispasmodic, which may facilitate smooth scope intubation and reduce patient discomfort during screening colonoscopy under current equipment settings.
Methods: A total of 70 patients undergoing colonoscopy under conscious sedation were randomized into two groups: a group with intravenous administration of 1 mg glucagon and a placebo group. After colonoscopy, patients completed questionnaires on pain, abdominal fullness, and acceptance of future colonoscopy. Difficulty in scope manipulation was scored by endoscopists, and times for cecal intubation, observation, and the number of polyps detected by colonoscopy were also recorded. In addition, we evaluated patient discomfort objectively with a newly developed portable analyzer of salivary amylase activity. This study was performed double-blind, and assignments were not disclosed to patients or to endoscopists.
Results: Scores for acceptance for future colonoscopy, pain, abdominal fullness, and scope manipulation were significantly lower in the glucagon group. Salivary amylase activity, determined at the time the scope was inserted to the cecum, was significantly lower in the glucagon group, and cecal intubation time was significantly shorter in the glucagon group. Observation time and polyp detection rate were not significantly different between the groups.
Conclusion: These results indicate that intravenous administration of glucagon can reduce patient discomfort and improve scope intubation during screening colonoscopy.