The efficacy of on-demand sedation colonoscopy: a STROBE-compliant retrospective cohort study



Colonoscopy has been routinely performed with sedation. Previous studies showed that on-demand sedation colonoscopy is acceptable in patients. We aim to compare the clinical outcomes of patients undergoing colonoscopy with and without sedation.


A prospectively collected retrospective matched cohort study was performed. 290 consecutive patients who underwent colonoscopy without sedation were included into the study. Another 290 patients who underwent colonoscopy with sedation were then selected based on matched sex and age group distribution. Data were collected in a prospective database. Age, sex, race, and procedural variables were collected. Outcomes analyzed included adenoma detection rate, Boston bowel preparation scores, time spent in the recovery room, cecal intubation time, and presence of pain during colonoscopy.


A total of 580 patients were included in the study. Of the 290 patients who underwent colonoscopy without sedation, 10 patients (3.45%) required sedation to be administered to complete the scope. Intention-to-treat analysis was performed. Multivariate analysis demonstrated that the administration of sedation was a significant predictor of prolonged recovery time (increase in 34.76 min, 95% CI 29.56–39.55, p < 0.001). Comparing the group who underwent colonoscopy without sedation to the group who underwent colonoscopy with sedation, there was no statistically significant difference in mean cecal intubation time (11.28 vs. 10.38 min, p = 0.129), adenoma detection rates (25.1 vs. 35.8%, p = 0.060), percentage of patients who experienced no pain at all during the procedure (93.5 vs. 93.5%, p = 1.000), and Boston bowel preparation scores (2.23 vs. 2.34, p = 0.370).


Our data suggest that on-demand sedation colonoscopy can be performed in patients, with a significant decrease in time spent in the recovery room prior to discharge. Cecal intubation time, adenoma detection rates, and percentage of patients experiencing no pain at all during the procedure were similar in both groups of patients.

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Correspondence to Hung Leng Kaan.

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Hung Leng Kaan, Vincent Khor, Wei Chee Liew, Tian Fu Loh, Sze Wai Leong, Shuo Ling Teo, and Christopher Hang Liang Keh declare that they have no conflict of interest or financial ties to disclose.

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Kaan, H.L., Khor, V., Liew, W.C. et al. The efficacy of on-demand sedation colonoscopy: a STROBE-compliant retrospective cohort study. Surg Endosc (2021).

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  • Colonoscopy
  • Sedation
  • On demand