PTU-205 Pre-medication with N-acetylcysteine and simethicone improves mucosal visualisation during gastroscopy. A randomised, controlled, endoscopist-blinded study
Authors: J Neale, S James, P Patel
Journal: Gut (2012)

<h3>Introduction</h3> The detection of early cancer during gastroscopy in the western world is poor. UK studies have demonstrated up to a 15% miss rate during diagnostic gastroscopy for early neoplasia. Early gastric cancer has a vastly superior survival rate and may be amenable to endoscopic resection. Diagnostic gastroscopy provides a unique opportunity to diagnose early gastric neoplasia, whatever the indication; however intraluminal mucus and saliva can obscure mucosal visualisation and potential detection of these lesions. The aim of this study was to investigate whether the use of a premedication solution containing the mucolytic agent N-acetylcysteine and the surfactant simethicone improves mucosal visualisation within an unselected UK diagnostic gastroscopy service. <h3>Methods</h3> 75 consecutive patients were recruited from a single endoscopist9s diagnostic gastroscopy list. These were randomised into three groups. 1: Standard control—clear fluids only for 6 h, NBM for 2 h. 2: Placebo control – standard control + 100 ml sterile water (given 20–30 min prior to gastroscopy). 3: Solution – standard control + 100 ml investigated solution (20–30 min prior). The endoscopist was blinded to patient preparation. Inadequate mucosal visualisation was measured by assessing fluid/mucus during gastroscopy that could not be suctioned and required flushing with water. The volume of flush, the site at which it was used and the procedure time were recorded. <h3>Results</h3> All three groups showed no statistical difference for age, gender, priority or indication. The mean volume of flush required to obtain clear mucosa was significantly less in the <i>solution</i> group (12.1 ml (3.5–20.7)) compared to the <i>standard control</i> group (54.2 ml (39.2–69.2), p&lt;0.00003) and the <i>placebo control</i> group (61.0 ml (44.6–77.4), p&lt;0.00001). This significant difference was identified across all sites recorded in the upper GI tract, bar the OGJ where very little stubborn mucus was identified in all three groups. 61% of the <i>solution</i> group required no flushing at all, significantly more than the <i>standard control</i> group (13%, p&lt;0.002) and the <i>placebo control</i> group (9%, p&lt;0.0005). Mean procedure time was less in the <i>solution</i> group (8.5 min (7.1–9.9)) compared with the <i>standard control</i> (10.4 min (8.5–12.3), p&lt;0.075) and <i>placebo control</i> groups (10.5 min (9.3–11.7), p&lt;0.028). When patients on Barrett9s surveillance are excluded this is more significant. <i>Solution</i> (7.2 min (6.2–8.2)) vs <i>standard control</i> (8.8 min (7.3–10.1), p&lt;0.041) vs <i>placebo control</i> (10.2 min (8.6–11.8), p&lt;0.0031). <h3>Conclusion</h3> Premedication with NAC and simethicone is a low cost and well-tolerated method of dramatically improving visibility and procedure time during diagnostic gastroscopy. This simple intervention may improve detection of early gastric cancer. <h3>Competing interests</h3> None declared.