Common bile duct pressure changes after fentanyl, morphine, meperidine, butorphanol, and naloxone

Five groups of 10 patients received thiamylal, enflurane, nitrous oxide-oxygen anesthesia for elective cholecystectomy. The common bile duct was intubated via the cystic duct with a 16-g plastic catheter, and the control intraductal pressure was measured. Patients then were given equi-analgesic doses of fentanyl, morphine, meperidine, butorphanol, or placebo intravenously, and the common bile duct pressure was recorded for 20 min. Fentanyl, morphine, and meperidine significantly increased pressure in the common duct (P less than 0.001). Butorphanol produced only insignificant changes. Naloxone given 20 min later significantly (P less than 0.001) decreased pressure in patients given fentanyl, morphine, and meperidine. Naloxone given without narcotics caused an increase in pressure that, although statistically significant (P less than 0.03), was clinically insignificant. In five additional patients anesthetized with thiamylal, nitrous oxide-oxygen and intermittent doses of fentanyl, common bile duct pressures were normal.