S834 Simethicone and N-Acetylcysteine to Improve Gastric Mucosal Visualisation for Upper Gastrointestinal Endoscopy: A Validation Study in the South Indian Population

Introduction: Oral simethicone, a defoaming agent, is commonly administered prior to upper gastrointestinal (GI) endoscopy to enhance gastric mucosal visibility. It is used alone or in combination with N-acetylcysteine (NAC), a mucolytic agent. This study aims to evaluate the effectiveness of simethicone alone and in combination with NAC in improving mucosal visibility during conscious endoscopy in a South Indian population with local spray endoscopy. Methods: A double-blind, blocked, quality improvement, real world study with 300 patients was performed at RajaRajeswari Medical College and Hospital Bangalore. Patients consented to an upper GI endoscopy while being conscious and were randomized by a computer algo to one of 3 groups (N = 100): Group A (simethicone), Group B (simethicone + NAC), or Group C (water). Premedication solutions were administered 20 minutes before endoscopy. Mucosal visibility was assessed at 5 anatomical sites (esophagus, body, fundus, antrum, and part one of duodenum) using a predefined 4-point scoring system (1 = clear view; 2 = clear view with some obstruction; 3 = view requiring <50 mL water flush; 4 = view requiring >50 ml water flush), with a maximum score of 20. Results: A total of 300 patients (median age = 42 years, 57.7% men and 42.3% women) were randomized into 3 groups. Mean total visibility scores were significantly lower (better) in Group A (5.18) and Group B (5.27) compared to Group C (10.6), P < 0.001. There was no statistically significant difference between Groups A and B (P > 0.19 across all sites), indicating that adding NAC to simethicone did not improve mucosal visibility. Antral pooling was lowest in Group A, with a small difference compared to Group B (0.9% lower), supporting the clinical advantage of simethicone alone. Water flushing was markedly reduced in Groups A and B, thereby lowering overall water usage without compromising mucosal clarity. The setting featured short procedures and high patient turnover, reflecting practical applicability in Indian clinical practice. Conclusion: Our study provided insight into usage of simethicone and NAC in conscious endoscopy in the South Indian population. Our results concluded that mucosal visibility was superior with the usage of the compounds rather than with water alone. Another confirmation of the better visibility was confirmed by the non-usage of flush during the procedure. Additionally, some antral pooling was observed with simethicone and NAC combination which may be verified with a larger study.