title: A pilot study to assess the safety and efficacy of carbon dioxide insufflation during colorectal endoscopic submucosal dissection with the patient under conscious sedation.
abstract: BACKGROUND
  Endoscopic submucosal dissection (ESD) is accepted as one of the treatments for en bloc resection of large superficial colorectal lesions. This procedure is performed by using air insufflation, is time consuming, and is associated with severe abdominal discomfort. The safety and efficacy of carbon dioxide (CO(2)) insufflation during colonoscopy already has been assessed in some trials.
  
  
  OBJECTIVE
  To assess the safety and efficacy of CO(2) insufflation instead of air insufflation during colorectal ESD with the patient under conscious sedation.
  
  
  METHODS
  A case-control series with a historical control.
  
  
  METHODS
  A total of 35 consecutive patients were enrolled in this study. Another 35 consecutive patients who previously received colorectal ESDs by using air insufflation were included as a historical control.
  
  
  METHODS
  Arterial partial pressure of CO(2) (pCO(2)) was measured before and after each procedure with the total dose of midazolam used as an index of abdominal discomfort.
  
  
  RESULTS
  The mean (standard deviation [SD]) operation time was 90 +/- 57 minutes in the CO(2) group and 100 +/- 80 minutes in the control group (not significant). In the CO(2) group, the mean (SD) dose of midazolam was significantly lower than that of the control group; 5.6 +/- 4.9 mg and 9.7 +/- 5.9 mg, respectively (P = .005). Blood analysis revealed a slight pCO(2) elevation in the CO(2) group; however, only 2 patients complained of mild abdominal discomfort.
  
  
  CONCLUSIONS
  Abdominal discomfort and pCO(2) were not evaluated in the control group.
  
  
  CONCLUSIONS
  This study strongly suggests that CO(2) insufflation is safe and effective during lengthy colonic endoscopic procedures, eg, ESD, with the patient under conscious sedation.
authors.affiliation: Division of Endoscopy, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Saito
authors.forename: Toshio
authors.initials: T
authors.lastname: Uraoka
authors.forename: Takahisa
authors.initials: T
authors.lastname: Matsuda
authors.forename: Fabian
authors.initials: F
authors.lastname: Emura
authors.forename: Hisatomo
authors.initials: H
authors.lastname: Ikehara
authors.forename: Yumi
authors.initials: Y
authors.lastname: Mashimo
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Kikuchi
authors.forename: Takahiro
authors.initials: T
authors.lastname: Kozu
authors.forename: Daizo
authors.initials: D
authors.lastname: Saito
mesh_terms: D018686:Anesthetics, Intravenous / Q000008:administration & dosage; D002245:Carbon Dioxide / Q000008:administration & dosage*; D003113:Colonoscopy / Q000379:methods*; D015179:Colorectal Neoplasms / Q000473:pathology / Q000601:surgery*; D016292:Procedural Sedation; D006801:Humans; D007275:Injections, Intravenous; D007327:Insufflation; D007413:Intestinal Mucosa / Q000473:pathology / Q000601:surgery*; D008874:Midazolam / Q000008:administration & dosage; D010865:Pilot Projects; D012189:Retrospective Studies; D016896:Treatment Outcome
chemical_list: D018686:Anesthetics, Intravenous; D002245:Carbon Dioxide; D008874:Midazolam