Target-controlled infusion of remifentanil with or without flurbiprofen axetil in sedation for extracorporeal shock wave lithotripsy of pancreatic stones: a prospective, open-label, randomized controlled trial

BACKGROUND: Extracorporeal shock wave lithotripsy (ESWL) is an effective therapeutic method used to treat patients with pancreatic stones. However, the anesthesia for this procedure has been underappreciated, with minimal reports of these procedures in certain case series with general or epidural anesthesia. METHODS: A cohort of 60 patients who elected to undergo ESWL in order to treat pancreatic stones for the first time were randomly selected and divided into two groups. One group of patients received target controlled infusion (TCI) of remifentanil, while the other group of patients received TCI of remifentanil plus a bolus of flurbiprofen axetil (a cyclooxygenase inhibitor) (Rem group and Rem + Flu group, n = 30 for each group). The Dixon’s up-and-down method was used to calculate the half maximum effective concentration (EC(50)) of remifentanil. Visual analogue scales of pain, Ramsay sedation scale, hemodynamic changes, and adverse events were also recorded. RESULTS: The EC(50) of remifentanil was calculated to be 4.0 ng/ml (95 % confidential interval: 3.84 ng/ml, 4.16 ng/ml) and 2.76 ng/ml (95 % confidential interval: 2.63 ng/ml, 2.89 ng/ml) in the Rem group and Rem + Flu group respectively (p < 0.001). Pain score was comparable between the two groups, while the Ramsay sedation scale was higher in the Rem group. Hemodynamic data showed that patients in the Rem group experienced higher mean arterial pressures and higher heart rates across the procedures. Patients in Rem group demonstrated a lower respiratory rate (p < 0.001) and a lower SpO(2) (p = 0.001). Less adverse events occurred in Rem + Flu group, including a reduced respiratory depression requiring wake-up as well as reduced postoperative nausea and vomiting. CONCLUSION: Remifentanil plus flurbiprofen axetil provided satisfactory analgesia and sedation for ESWL of pancreatic stones with less adverse events. (Clinicaltrial.gov: NCT01998217; registered on November 19, 2013)