Skip to main content

Research Repository

Advanced Search

Randomized clinical trial of Entonox versus midazolam-fentanyl sedation for colonoscopy

Maslekar, S; Gardiner, Anji; Duthie, Graeme


S Maslekar

Anji Gardiner

Graeme Duthie


BACKGROUND Intravenous sedation for colonoscopy is associated with cardiorespiratory complications and delayed recovery. The aim of this randomized clinical trial was to compare the efficacy of Entonox (50 per cent nitrous oxide and 50 per cent oxygen) and intravenous sedation using midazolam-fentanyl for colonoscopy. METHODS Some 131 patients undergoing elective colonoscopy were included. Patients completed a Hospital Anxiety and Depression questionnaire, letter cancellation tests and pain scores on a 100-mm visual analogue scale before, immediately after the procedure and at discharge. They also completed a satisfaction survey at discharge and 24 h after the procedure. RESULTS Sixty-five patients were randomized to receive Entonox and 66 to midazolam-fentanyl. Completion rates were similar (94 versus 92 per cent respectively; P = 0.513). Patients receiving Entonox had a shorter time to discharge. They reported significantly less pain (mean score 16.7 versus 40.1; P < 0.001), and showed better recovery of psychomotor function immediately after the procedure and at discharge. Patient satisfaction was higher among patients who received Entonox (median score 96 versus 89; P = 0.001). CONCLUSION Entonox provides better pain relief and faster recovery than midazolam-fentanyl and so is more effective for colonoscopy.


Maslekar, S., Gardiner, A., & Duthie, G. (2009). Randomized clinical trial of Entonox versus midazolam-fentanyl sedation for colonoscopy. British journal of surgery, 96(4), 361 - 368.

Journal Article Type Article
Acceptance Date Apr 30, 2009
Publication Date Apr 30, 2009
Journal The British journal of surgery
Print ISSN 0007-1323
Publisher Wiley
Peer Reviewed Peer Reviewed
Volume 96
Issue 4
Pages 361 - 368
Public URL
PMID 19283736