Prospective cohort study evaluating premedication with simethicone and n-acetilcysteine for upper diagnostic gastrointestinal endoscopy

The use of premedication for upper gastrointestinal endoscopy (UGE) is not widely established in western countries. The primary aim was to compare gastric visibility according to the total visibility score (TVS). As secondary aim to assess complications, diagnostic yield, endoscopic procedure time, sedation dose and patient' satisfaction.Single center prospective cohort study including consecutive adults undergoing an UGE in the afternoon working shift. After completing enrolment in the control group, patients were administered 200 mg simethicone and 500 mg N-acetylcysteine diluted in 100 ml of water15 minutes before the procedure. All procedures were recorded and a single, blinded endoscopist evaluated the TVS after recruitment of both cohorts. Patient' satisfaction was evaluated using the Spanish translation of the American Society of Gastrointestinal Endoscopy satisfaction questionnaire.205 patients were included, 103 females (50.2%) with a median age of 54.8-years (IQR: 41.2-65.2). 104 were enrolled to the control group and 101 to the intervention group. Patients receiving premedication presented a higher rate of adequate gastric visibility (74.3% vs 45.2; difference 95% CI: 16,3-41,9%, p0.001) and excellent (23.8% vs 7.7%; difference 95% CI: 6,3-25,8%, p=0.002). Propofol dose was similar, although median procedure time was lower in the group of no intervention [5 (IQR: 4-7) vs 6 minutes (IQR: 5-7); p=0.03]. Procedure related adverse events were similar, except that patient without premedication experienced more nausea episodes. Major and minor endoscopic findings and the satisfaction questionnaire showed no differences between both groups.Patients receiving premedication with simethicone and N-acetylcysteine presented a better gastric visibility score, without increase in adverse events or affecting the patients' satisfaction.