Opioids are increasingly being administered intrathecally as adjuncts to local anesthetics. They enhance spinal anesthesia without prolonging motor recovery. We evaluated the effect of 10 µg of fentanyl to bupivacaine on sensory, motor block and side effects.

Thirty six patients undergoing urologic surgery were randomized into two groups. Control group received bupivacaine 10 mg combined with normal saline 0.2 ml, and Fentanyl group received bupivacaine 10 mg with fentanyl 10 µg (0.2 ml).

There were no significant differences between two groups in the peak level of sensory block, onset of peak level, duration of motor block, and side effects. However, the time of regression from peak level to T10 in Fentanyl group was longer significantly than that of Control group.

Intrathecal small dose fentanyl (10 µg) on bupivacaine spinal blockade prolonged duration of sensory block and did not augment side effects and provide reliable anesthesia for urologic surgery.