Brachial plexus block: Effect of the addition of sufentanil to the mixture of local anaesthetics on duration of postoperative analgesia.

Objectives: To compare the quality and the duration of analgesia produced by a supraclavicular brachial plexus blockade obtained with a mixture of lidocaine and bupivacaine when supplemented or not with sufentanil. Study design: Prospective, randomized, double-blind study. Patients: The study included 40 patients undergoing osteosynthesis of the upper limb under brachial plexus block, randomly assigned to two groups. Methods: The patients of the control group were given 0.5% bupivacaine 1 mg . kg(-1) and 1% lidocaine 2 mg . kg(-1). Those of the sufentanil group, received the same mixture supplemented with sufentanil 0,2 mg . kg(-1). During the postoperative period, the characteristics of analgesia were blindly evaluated every hour for 48 h with a visual analogic scale graduated from 0 to 100. Analgesia was considered satisfactory when the score was below 30. Adverse effects of opiates (drowsiness, pruritus, nausea and vomiting) were also assessed. Oxygen saturation was continuously monitored. Blood pressure, heart and respiratory rates were measured at the same intervals than analgesia. Duration of analgesia are expressed as medians (range) and compared using a Mann and Whitney's U test. Results: The respective durations of satisfactory analgesia were significantly different. 12.5 h (8-17) in the control group versus 24 h (8-48) for the sufentanil group. The adverse effects in the sufentanil group were nausea (2), vomiting (1) and pruritus (1). No respiratory depression was noted. Conclusion: Sufentanil added to a mixture of lidocaine and bupivacaine increases twofold the duration of postoperative analgesia following brachial plexus blockade.