Administration of additional analgesics can decrease the incidence of paradoxical reactions in patients under benzodiazepine-induced sedation during endoscopic transpapillary procedures: prospective randomized controlled trial.

The aim of the present study was to evaluate the efficacy and safety of giving pentazocine as an analgesic with benzodiazepine during endoscopic retrograde cholangiopancreatography (ERCP). The paradoxical reactions (PR) incidence was evaluated as an indicator of usefulness. Transcutaneous arterial carbon dioxide tension (PtcCO(2) ) was evaluated as an indicator of safety. A total of 160 patients were enrolled. Subjects were randomly divided into two groups; group 1 sedated with midazolam only and group 2 sedated both with midazolam and pentazocine (7.5 mg). The initial dosage introduced sedation before procedure was significantly higher in group 1. The occurrence rate of PR's in group 1 was significantly higher compared to that in group 2 (P = 0.0108). Although maximum PtcCO(2) observed during sedation did not differ between the two groups (48.7 ± 7.2, 50.3 ± 7.6 mmHg, respectively),maximum PtcCO(2) during the first 15 min after the start of sedation was significantly higher in group 2 than in group 1 (P = 0.0294). In multivariate analysis, procedure duration (odds ratio [OR] = 1.048) and midazolam dose (OR = 1.221) were predictive factors for PR. The administration of pentazocine is significantly reduced the incidence of PR's in patients under midazolam induced sedation during ERCP.