The use of bupivacaine and fentanyl for spinal anesthesia for urologic surgery

We evaluated the effect of 25 mug of fentanyl added to bupivacaine on sensory and motor block. By using a double-blinded study design, 80 men undergoing urologic surgery were randomized into the following four groups: Group I, bupivacaine 10 mg; Group II, bupivacaine 10 mg + fentanyl 25 mug;Group III, bupivacaine 7.5 mg + fentanyl 25 mug;Group IV,bupivacaine 5 mg + fentanyl 25 mug. The final volume of intrathecal injectate was adjusted to 2.5 mt with sterile distilled water. Spinal anesthesia was administered with the 27-gauge Whitacre needle at the L2-3 interspace with the patient in the sitting position. Neural block was assessed by using pinprick and a modified Bromage scale. The degree of motor block was more profound in Group II compared with Group I at the end of operation. In Group IV, there was no motor block at the end of operation in any of the patients. The median level of the upper limit of the sensory block was higher than T-7 in all groups before the start of surgery. The addition of 25 mug of fentanyl to 5 mg of bupivacaine resulted in short-acting motor block. When 25 mug of fentanyl was added to 10 mg of bupivacaine, it increased the intensity and duration of motor block. Only 5 (6.3%) of the patients needed supplemental analgesia during the operation.