title: Pre-medication to improve esophagogastroduodenoscopic visibility: a meta-analysis and systemic review.
abstract: OBJECTIVE
  The use of pre-medication to improve visibility in gastrointestinal endoscopy has not been well addressed and remains controversial. The aim is to evaluate the effects of current pre-medication on endoscopic visualization.
  
  
  METHODS
  We made the overall strategies to search the different databases and assessed the quality of included studies according to the included and excluded standard. 1541 patients were treated with pre-medication.
  
  
  RESULTS
  Ten prospective studies involving 1541 patients were included. There was improved visibility in patients treated with Simethicone (weighted mean difference -4.3; 95% confidence interval (CI), -4.94 to -3.67), compared to those who did not use Simethicone. In the Simethicone based regiment, administration of Pronase was noted with significantly improved visibility in the location of antrum and fundus, compared to those who did not use; however, administration of N-acetyl-L-cysteine could not lead to significantly improved visibility. Simethicone offered better visibility than N-acetyl-L-cysteine and Pronase alone.
  
  
  CONCLUSIONS
  There is improved visibility with pre-medication using Simethicone before esophagogastroduodenoscopy. In the Simethicone based regimen, administration of Pronase or N-acetyl-Lcysteine may be of little use in improving visibility. Based on the literature review, Simethicone dissolved in the water with the acceptably lowest ratio of 0.7 can still offer the good visibility but 30 mL of water should be avoided.
authors.forename: Hsuan-Wei
authors.initials: HW
authors.lastname: Chen
authors.forename: Hsuang-Chun
authors.initials: HC
authors.lastname: Hsu
authors.forename: Tsai-Yuan
authors.initials: TY
authors.lastname: Hsieh
authors.forename: Ming-Kung
authors.initials: MK
authors.lastname: Yeh
authors.forename: Wei-Kuo
authors.initials: WK
authors.lastname: Chang
mesh_terms: D000111:Acetylcysteine / Q000008:administration & dosage; D000934:Antifoaming Agents / Q000008:administration & dosage*; D016009:Chi-Square Distribution; D016145:Endoscopy, Digestive System; D005100:Expectorants / Q000008:administration & dosage; D041981:Gastrointestinal Tract / Q000473:pathology*; D006801:Humans; D011237:Predictive Value of Tests; D011292:Premedication; D011402:Pronase / Q000008:administration & dosage; D012841:Simethicone / Q000008:administration & dosage*
chemical_list: D000934:Antifoaming Agents; D005100:Expectorants; D012841:Simethicone; D011402:Pronase; D000111:Acetylcysteine