A randomized controlled trial of pre-procedure simethicone and N-acetylcysteine to improve mucosal visibility during gastroscopy – NICEVIS

Abstract

Background and study aims: Mucosal views can be impaired by residual bubbles and mucus during gastroscopy. This study aimed to determine whether a pre-gastroscopy drink containing simethicone and N-acetylcysteine improves mucosal visualisation. Patients and methods: We conducted a randomized controlled trial recruiting 126 subjects undergoing routine gastroscopy. Subjects were randomized 1:1:1 to receive: A—pre-procedure drink of water, simethicone and N-acetylcysteine (NAC); B—water alone; or C—no preparation. Study endoscopists were blinded to group allocation. Digital images were taken at 4 locations (lower esophagus/upper gastric body/antrum/fundus), and rated for mucosal visibility (MV) using a 4-point scale (1 = best, 4 = worst) by 4 separate experienced endoscopists. The primary outcome measure was mean mucosal visibility score (MVS). Secondary outcome measures were procedure duration and volume of fluid flush required to achieve adequate mucosal views. Results: Mean MVS for Group A was significantly better than for Group B (1.35 vs 2.11, P < 0.001) and Group C (1.35 vs 2.21, P < 0.001).Mean flush volume required to achieve adequate mucosal views was significantly lower in Group A than Group B (2.0 mL vs 31.5 mL, P = 0.001) and Group C (2.0 mL vs 39.2 mL P < 0.001). Procedure duration did not differ significantly between any of the 3 groups.MV scores at each of the 4 locations demonstrated significantly better mucosal visibility in Group A compared to Group B and Group C (P < 0.0025 for all comparisons). Conclusions: A pre-procedure drink containing simethicone and NAC significantly improves mucosal visibility during gastroscopy and reduces the need for flushes during the procedure. Effectiveness in the lower esophagus demonstrates potential benefit in Barrett’s oesophagus surveillance gastroscopy.

Improving the mucosal visualization at gastroscopy: a systematic review and meta-analysis of randomized, controlled trials reporting the role of Simethicone ± N-acetylcysteine

“…The resulting evidence form this meta-analysis is in concordance with previously published several studies (15,(28)(29)(30)(31)(32)(33)(34)(35)(36)(37) and at least two systematic reviews (38,39). First systematic review (38) was published in 2011 but has limitations of analysing trials investigating the role of Simethicone ± NAC in OGD, colonoscopy and capsule endoscopy.…”

“…A total of 171 studies were identified from Scopus, Medline and other electronic databases. Among them, 7 RCTs (n=1,099), published until March 2018, were eligible for inclusion (28)(29)(30)(31)(32)(33)(34)(35)(36); and the reasons for ineligibility are described in PRISMA flow chart Figure 1. The extracted data from the included trials is given in Tables 1 and 2.…”

Upper gastrointestinal tract capsule endoscopy using a nurse-led protocol: First reported experience

“…Some UGI videos were obscured by adherent mucus in the proximal stomach. The use of mucolytics such as N-acetylcysteine or pronase has been shown to be of benefit in improving mucosal visibility during gastroscopy[ 37 - 39 ], although this did not translate to the only capsule endoscopy study to date[ 40 ]. Routine use of hyoscine has been advocated to improve visualisation in OGD[ 14 ].…”

Reassessing the value of gastroscopy for the investigation of dyspepsia

“…This might be because of time pressures resulting in OGD being performed too rapidly, a lack of training in recognition of early malignant disease or poor tolerance of the procedure, resulting in inadequate insufflation or an abbreviated examination. The use of antifoaming agents and mucolytics may also improve mucosal visualisation and early lesion detection 17. Cheung et al showed that alarm features were significantly less likely at presentation in these patients than those identified at first OGD 18…”