Comparison of intrathecal bupivacaine and ropivacaine with different doses of sufentanil

Background: Spinal bupivacaine produces a complete anaesthetic block of a longer duration than ropivacaine, which leads to a potentially increased risk of failure. A combination of sufentanil to ropivacaine may improve the block's reliability. Methods: Sixty-four patients, scheduled for varicose vein stripping or the tension-free vaginal tape procedure, were allocated to receive double-blindly, spinal bupivacaine 10 mg (Group 1) or ropivacaine 10 mg without (Group 2) or with sufentanil 2.5 mcg (Group 3), 5 mcg (Group 4). Sensory block was tested with pinprick and motor block was evaluated with the Bromage scale until full recovery. The primary endpoint was to compare the duration of sensory block evaluated by regression to S2. Results: In comparison with bupivacaine, ropivacaine produced a shorter duration sensory block (median at 68, 90 and 120 min in groups 2, 3 and 4, respectively, vs. 150 min in Group 1) and motor block (median at 90, 98 and 120 min in groups 2, 3 and 4 vs. 180 min in Group 1). Motor blockade was significantly less important in patients receiving spinal ropivacaine (median values for the Bromage scale at 3 in groups 2, 3 and 4, vs. 1 in Group 1). Pruritus was significantly more frequent in patients receiving spinal sufentanil (Groups 3 and 4 vs. Groups 1 and 2). Conclusion: Plain bupivacaine 10 mg has a longer recovery profile than the same dose of ropivacaine with or without sufentanil.