A randomized controlled trial of improvement of endoscopic visibility in the upper gastrointestinal tract with N-acetylcysteine

Abstract

Objective To determine the effects and dosage of N-acetylcysteine(NAC) in the improvement of the visibility in esophagogastroduodenoscopy(EGD). Methods A prospective randomized controlled study was performed on 193 patients scheduled for EGD from November 2014 to July 2015 were randomized into five groups using digital table. In group A, 100 mg dimethicone and 2 g NaHCO3 were given. In group B, 100 mg dimethicone, 2 g NaHCO3 and 20 000 U pronase were given. Group C received 100 mg dimethicone, 2 g NaHCO3 and 200 mg NAC. Group D received 100 mg dimethicone, 2 g NaHCO3 and 400 mg NAC and group E 100 mg dimethicone, 2 g NaHCO3 and 600 mg NAC.The agents were dissolved in 100 ml water for each patient.Endoscopy was completed by one endoscopist and the score of image visibility assessment was completed by 2 other endoscopists. The 3 endoscopists were unaware of grouping.The total scores, the time of washing, the time of examination and complications were compared and analysed. Results The total image scores of group A, B, C, D and E were 30.83±3.78, 35.69±2.88, 33.16±3.90, 34.95±3.46 and 36.76±2.91, respectively. Group A was the lowest(P 0.05). Images that were scored 3 were the most in group E. The washing times of each group were 38.00±19.10, 17.03±11.44, 15.92±10.81, 15.78±10.24 and 15.55±9.69, and the examination times of each group were 13.49±2.49, 9.41±1.86, 9.08±1.80, 8.73±1.91 and 8.78±1.79 minutes.Group A was the longest in these two indices(P 0.05). Conclusion The preoperative NAC can improve the visibility in EGD. The best dose is 600 mg, whose effects and safety were similar to those of 20 000 U, but yield to less washing time and the examination time in EGD. Key words: Gastroscopy; Acetylcysteine; Pronase; Endoscopic image quality