LAUSR

BACKGROUND AND OBJECTIVE Endoscopic retrograde cholangiopancreatography (ERCP) is essential for visualising the biliary tree and pancreatic ducts, and carbon dioxide (CO2) insufflation during ERCP is considered an alternative technique to air insufflation for relieving post-procedural abdominal discomfort (abdominal pain and distension). The aim of the present study was to evaluate the effect of CO2 insufflation on the remission of abdominal discomfort and the potential side effects by conducting a meta-analysis. METHODS The method recommended by the Cochrane Collaboration was employed to conduct a meta-analysis of randomised controlled trials (RCTs) of CO2 insufflation versus air insufflation during ERCP. The PubMed, EMBASE, Cochrane Library, ISI Web of Science and China Biology Medicine disc (CBMdisc) databases were comprehensively searched. RESULTS Nine high-quality RCTs were reviewed. The updated meta-analysis showed that the CO2 groups achieved a lower abdominal pain score [1-hour (SMD: -1.44, 95% CI: -2.76, -0.15), 3-hour (SMD: -1.17, 95% CI: -2.18, -0.16) and 6-hour (SMD: -1.39, 95% CI: -2.68, -0.10)], a lower abdominal distension score [1-hour (SMD: -1.05, 95% CI: -1.73, -0.38), 3-hour (SMD: -0.63, 95% CI: -1.10, -0.16) and 6-hour (SMD: -0.54, 95% CI: -0.99, -0.08)] and a lower overall rate of complications (OR: 0.59; 95% CI: 0.37, 0.93). There was no significant difference between the groups regarding abdominal discomfort immediately after recovery or 24-hour post-procedure. There was no evidence to indicate higher pressure of CO2 (pCO2) values in the CO2 groups during the procedure when the patients were under sedation anaesthesia. CONCLUSIONS Compared to air insufflation, CO2 insufflation is currently the preferred method for ERCP and decreases post-procedural abdominal pain and distension without significant side effects.