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 senso ry and motor block. By using a double-blinded study design, 80 men undergoi ng urologic surgery were randomized into the following four groups: Group I , bupivacaine 10 mg; Group II, bupivacaine 10 mg + fentanyl 25 mug;Group II I, bupivacaine 7.5 mg + fentanyl 25 mug;Group IV,bupivacaine 5 mg + fentany l 25 mug. The final volume of intrathecal injectate was adjusted to 2.5 mt with sterile distilled water. Spinal anesthesia was administered with the 2 7-gauge Whitacre needle at the L2-3 interspace with the patient in the sitt ing position. Neural block was assessed by using pinprick and a modified Br omage scale. The degree of motor block was more profound in Group II compar ed with Group I at the end of operation. In Group IV, there was no motor bl ock 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 bupivac aine resulted in short-acting motor block. When 25 mug of fentanyl was adde d 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.