Randomized Clinical Trial
Copyright ©The Author(s) 2016. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Pharmacol Ther. Nov 6, 2016; 7(4): 572-578
Published online Nov 6, 2016. doi: 10.4292/wjgpt.v7.i4.572
Efficacy of small-volume simethicone given at least 30 min before gastroscopy
Mingjun Song, Andrew Boon Eu Kwek, Ngai Moh Law, Jeannie Peng Lan Ong, Jessica Yi-Lyn Tan, Prem Harichander Thurairajah, Daphne Shih Wen Ang, Tiing Leong Ang
Mingjun Song, Andrew Boon Eu Kwek, Ngai Moh Law, Jeannie Peng Lan Ong, Jessica Yi-Lyn Tan, Prem Harichander Thurairajah, Daphne Shih Wen Ang, Tiing Leong Ang, Department of Gastroenterology and Hepatology, Changi General Hospital, Singapore 529889, Singapore
Author contributions: Song M, Kwek ABE and Ang TL were responsible for the study conception and design; Song M was responsible for data analysis and interpretation, and manuscript drafting; Kwek ABE and Ang TL critically revised the article for important intellectual content; all the authors reviewed and approved the final version to be published.
Supported by Changi General Hospital Research Grant, No. 2015[CHF2015.02-S].
Institutional review board statement: The study was reviewed and approved by the SingHealth Centralized Institutional Review Board (Ref: 2015/2519).
Clinical trial registration statement: The study is registered under clinicaltrials.gov (NCT02555228).
Informed consent statement: All study participants provided informed written consent prior to study enrollment.
Conflict-of-interest statement: All authors declare no potential conflicting interests related to this paper.
Data sharing statement: No additional data are available.
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: Tiing Leong Ang, Chief, Department of Gastroenterology and Hepatology, Changi General Hospital, 2 Simei Street 3, Singapore 529889, Singapore. tiing_leong_ang@cgh.com.sg
Telephone: +65-68503974 Fax: +65-67816202
Received: June 27, 2016
Peer-review started: June 28, 2016
First decision: August 10, 2016
Revised: August 16, 2016
Accepted: October 17, 2016
Article in press: October 19, 2016
Published online: November 6, 2016
Processing time: 125 Days and 10 Hours
Abstract
AIM

To evaluate the efficacy of 5 mL simethicone solution in decreasing gastric foam if given at least 30 min before gastroscopy.

METHODS

This was a randomized, placebo controlled, endoscopist blinded study performed at Changi General Hospital. Patients were at least 21 years old, had no prior surgical resection of the upper gastrointestinal tract, and scheduled for elective diagnostic gastroscopies. The primary outcome was the total mucosal visibility score (TMVS) which was evaluated using McNally score. The sample size was calculated to be 24 per group (SD 2.4, 80% power, P < 0.05, 2-sample t test).

RESULTS

Fifty-four patients were randomised to receive either simethicone [1 mL liquid simethicone (100 mg) in 5 mL of water] or placebo (5 mL of water) at least 30 min before their gastroscopy. Six accredited consultants conducted the gastroscopy, and the interobserver agreement of scoring TMVS was good with a Kappa statistic of 0.73. The simethicone group had significantly better mean TMVS compared to placebo (5.78 ± SD 1.65 vs 8.89 ± SD 1.97, P < 0.001). The improvement was statistically significant for the duodenum and the gastric antrum, angularis, body, and fundus. Percent 51.9 of patients in the simethicone group had a TMVS of 4 (no bubbles at all) to 5 (only 1 area with minimal bubbles), while in the placebo group 3.7% of patients had TMVS of 4 or 5. The number needed to treat was 2.1 to avoid a TMVS of 6 and more. The simethicone group also had a significantly shorter procedure time with less volume of additional flushes required during gastroscopy to clear away obscuring gastric foam.

CONCLUSION

With a premedication time of at least 30 min, 5 mL simethicone can significantly decrease gastric foam, decrease the volume of additional flushes, and shorten gastroscopy time.

Keywords: Simethicone; Premedication; Gastroscopy; Gastric foam

Core tip: This is the first study to evaluate the efficacy of a low volume (5 mL) simethicone solution compared to a placebo using the McNally score to calculate the total mucosal visibility for gastroscopy. Our study showed that although earlier studies had favored higher volumes (typically 100 mL), a low volume is still effective as long as adequate premedication time of at least 30 min is allowed. Such a small volume is more suitable for patients with swallowing difficulties and the formulation had excellent patient compliance with no adverse effects.