Retrospective Cohort Study
Copyright ©The Author(s) 2017. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Endosc. Sep 16, 2017; 9(9): 471-479
Published online Sep 16, 2017. doi: 10.4253/wjge.v9.i9.471
Colonoscopy quality with Entonox®vs intravenous conscious sedation: 18608 colonoscopy retrospective study
Alexander R Robertson, Nicholas A Kennedy, James A Robertson, Nicholas I Church, Colin L Noble
Alexander R Robertson, Colin L Noble, Department of Gastroenterology, Western General Hospital, Edinburgh EH4 2XU, United Kingdom
Nicholas A Kennedy, Centre for Genomic and Experimental Medicine, University of Edinburgh, Edinburgh EH4 2XU, United Kingdom
Nicholas A Kennedy, Department of Gastroenterology, University of Exeter, Exeter EX4 4QJ, United Kingdom
James A Robertson, School of Life Sciences, University of Nottingham, Nottingham NJ7 2UH, United Kingdom
Nicholas I Church, Royal Infirmary of Edinburgh, Edinburgh EH16 4SA, United Kingdom
Author contributions: Robertson AR, Kennedy NA and Noble CL designed the research; Robertson AR, Kennedy NA and Robertson JA were involved in data analysis and writing of the draft manuscript; Church NI and Noble CL critically revised the manuscript for important intellectual content.
Institutional review board statement: This study was performed as a service evaluation and in accordance with local and UK policy, there was no requirement for an ethics committee review.
Informed consent statement: Consent was not obtained but the presented data are anonymised and risk of identification is low.
Conflict-of-interest statement: None declared.
Data sharing statement: Technical appendix, statistical code, and dataset available from the corresponding author at colin.noble@nhslothian.scot.nhs.uk.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Colin L Noble, MBChB, MD, MRCP, Consultant Gastroenterologist, Department of Gastroenterology, Western General Hospital, Crewe Road South, Edinburgh EH4 2XU, United Kingdom. colin.noble@nhslothian.scot.nhs.uk
Telephone: +44-131-5371000
Received: March 26, 2017
Peer-review started: March 28, 2017
First decision: June 30, 2017
Revised: July 10, 2017
Accepted: August 15, 2017
Article in press: August 16, 2017
Published online: September 16, 2017
Processing time: 168 Days and 8.1 Hours
Abstract
AIM

To compare colonoscopy quality with nitrous oxide gas (Entonox®) against intravenous conscious sedation using midazolam plus opioid.

METHODS

A retrospective analysis was performed on a prospectively held database of 18608 colonoscopies carried out in Lothian health board hospitals between July 2013 and January 2016. The quality of colonoscopies performed with Entonox was compared to intravenous conscious sedation (abbreviated in this article as IVM). Furthermore, the quality of colonoscopies performed with an unmedicated group was compared to IVM. The study used the following key markers of colonoscopy quality: (1) patient comfort scores; (2) caecal intubation rates (CIRs); and (3) polyp detection rates (PDRs). We used binary logistic regression to model the data.

RESULTS

There was no difference in the rate of moderate-to-extreme discomfort between the Entonox and IVM groups (17.9% vs 18.8%; OR = 1.06, 95%CI: 0.95-1.18, P = 0.27). Patients in the unmedicated group were less likely to experience moderate-to-extreme discomfort than those in the IVM group (11.4% vs 18.8%; OR = 0.71, 95%CI: 0.60-0.83, P < 0.001). There was no difference in caecal intubation between the Entonox and IVM groups (94.4% vs 93.7%; OR = 1.08, 95%CI: 0.92-1.28, P = 0.34). There was no difference in caecal intubation between the unmedicated and IVM groups (94.2% vs 93.7%; OR = 0.98, 95%CI: 0.79-1.22, P = 0.87). Polyp detection in the Entonox group was not different from IVM group (35.0% vs 33.1%; OR = 1.01, 95%CI: 0.93-1.10, P = 0.79). Polyp detection in the unmedicated group was not significantly different from the IVM group (37.4% vs 33.1%; OR = 0.97, 95%CI: 0.87-1.08, P = 0.60).

CONCLUSION

The use of Entonox was not associated with lower colonoscopy quality when compared to intravenous conscious sedation using midazolam plus opioid.

Keywords: Gastrointestinal endoscopy; Colonoscopy; Caecal intubation; Benzodiazepine; Polyp detection; Nitrous oxide; Entonox; Midazolam; Sedation; Unsedated

Core tip: Previous studies have shown that colonoscopies performed with Entonox® gas are not associated with more patient discomfort, or lower caecal intubation rates, than those performed with intravenous conscious sedation. We have completed the largest and most comprehensive real-world retrospective study of Entonox use in colonoscopy. In particular, we compare colonoscopy quality with Entonox against intravenous conscious sedation using midazolam plus opioid. This study shows that Entonox is not associated with lower colonoscopy quality when compared to intravenous conscious sedation. Based on the results of this study, Entonox remains an attractive option for colonoscopy analgesia and sedation.