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

Maslekar, S.; Gardiner, A.; Hughes, M.; Culbert, B.; Duthie, G. S.


S. Maslekar

A. Gardiner

M. Hughes

B. Culbert

G. S. 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. Registration number: ISRCTN81142957 (


Maslekar, S., Gardiner, A., Hughes, M., Culbert, B., & Duthie, G. S. (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 Feb 23, 2009
Online Publication Date Mar 12, 2009
Publication Date 2009-04
Deposit Date Nov 13, 2014
Journal British Journal Of Surgery
Print ISSN 0007-1323
Electronic ISSN 1365-2168
Publisher Wiley
Peer Reviewed Peer Reviewed
Volume 96
Issue 4
Pages 361-368
Keywords REF 2014 submission**
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