title: Sedation-free colonoscopy using an upper endoscope is tolerable and effective in patients with low body mass index: a prospective randomized study.
abstract: OBJECTIVE
  Small-caliber upper endoscopes can be used safely and effectively for sedation-free colonoscopy. The objective of the study is to assess the efficacy of a small-caliber upper endoscope (9.2 mm) comparing with a standard colonoscope (12.2 mm).
  
  
  METHODS
  In a prospective trial, patients undergoing sedation-free colonoscopy were randomly assigned to the upper endoscope (E) or the standard colonoscope (C). Outcome measures included patient self-assessed pain score (4-point scale), endoscopist-assessed pain score (4-point scale), cecal intubation rate, difficult cecal intubation rate (>900 s), number of polyps detected, and complication rates.
  
  
  RESULTS
  A total of 244 patients were entered. Clinical characteristics were not different between the two groups. Cecal intubation was achieved in 91.0% of the patients in each group. The mean patient self-assessed pain score (SD) was significantly lower in the E group compared with the C group: 1.44 (0.81) versus 2.08 (1.10), p < 0.001. The mean endoscopist assessment of patient pain score (SD) was significantly lower in the E group compared with the C group as well: 1.27 (0.67) versus 1.58 (0.90), p= 0.003. In patients with low body mass index (BMI < 22 kg/m(2)), the cecal intubation rate was significantly higher in the E group (97.7%vs 79.4%, p= 0.026) and the difficult cecal intubation rate was significantly lower in the E group (9.3%vs 32.4%, p= 0.011). There were no significant differences in the number of polyps detected and complication rates between the two groups.
  
  
  CONCLUSIONS
  A small-caliber upper endoscope is tolerable and effective for sedation-free colonoscopy, especially in patients with low BMI.
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, Chonnam National University Medical School, Gwangju, South Korea.
authors.forename: Chang-Hwan
authors.initials: CH
authors.lastname: Park
authors.forename: Wan-Sik
authors.initials: WS
authors.lastname: Lee
authors.forename: Young-Eun
authors.initials: YE
authors.lastname: Joo
authors.forename: Hyun-Soo
authors.initials: HS
authors.lastname: Kim
authors.forename: Sung-Kyu
authors.initials: SK
authors.lastname: Choi
authors.forename: Jong-Sun
authors.initials: JS
authors.lastname: Rew
authors.forename: Sei-Jong
authors.initials: SJ
authors.lastname: Kim
mesh_terms: D015992:Body Mass Index; D002432:Cecum; D020685:Colonoscopes; D003113:Colonoscopy / Q000379:methods*; D019723:Endoscopes; D005260:Female; D006801:Humans; D007417:Intestinal Polyps / Q000473:pathology; D008297:Male; D008875:Middle Aged; D010146:Pain; D010342:Patient Acceptance of Health Care; D011446:Prospective Studies