Carbon dioxide insufflation during endoscopic retrograde cholangiopancreatography reduces bowel gas volume but does not affect visual analogue scale scores of suffering: a prospective, double-blind, randomized, controlled trial

Abstract

Endoscopic retrograde cholangiopancreatography (ERCP) and related procedures can cause abdominal pain and discomfort. Two clinical trials have indicated, using the visual analogue scale (VAS) score, that CO(2) insufflation during ERCP ameliorates the suffering of patients without complications, compared with air insufflation. However, differences in patient suffering between CO(2) and air insufflation after ERCP under deep conscious sedation have not been reported. We focused on the gas volume score (GVS) as an objective indicator of gas volume, and designed a multicenter, prospective, double-blind, randomized, controlled study with CO(2) and air insufflation during ERCP. Between March 2010 and August 2010, 80 patients who required ERCP were enrolled and evenly randomized to receive CO(2) insufflation (CO(2) group) or air insufflation (air group). ERCP and related procedures were performed under deep conscious sedation with fentanyl citrate or pethidine and midazolam or diazepam. The GVS was evaluated as the primary endpoint in addition to the VAS score as the secondary endpoint. The GVS after ERCP and related procedures in the CO(2) group was significantly lower than that in the air group (0.14 ± 0.06 vs. 0.31 ± 0.11, P < 0.01), as well as the rate of increase in GVS ([GVS after - GVS before]/[GVS before ERCP and related procedures] × 100) (3.8 ± 5.9 vs. 21 ± 11.1%, P < 0.01). VAS scores 3 and 24 h after ERCP and related procedures were comparable between the CO(2) and air groups for abdominal pain, abdominal distension, and nausea. Additionally, VAS scores were not correlated with the GVS. CO(2) insufflation during ERCP reduces GVS (bowel gas volume) but not the VAS score of suffering compared with air insufflation. Deep and sufficient sedation during ERCP and related procedures is important for the palliation of patients' pain and discomfort.