The purpose of the present study is to investigate the anesthetic effect of reduced doses of spinal bupivacaine with epidural top ups in comparison with those of spinal bupivacaine and to determine the adequate doses of drugs used during lower extremity surgeries.

Sixty adult patients were randomized to three different technique groups: S group (10 mg of spinal bupivacaine), SE1 group (7.5 mg of spinal bupivacaine + epidural 1.5% lidocaine 10 ml) or SE2 group (5 mg of spinal bupivacaine + epidural 1.5% lidocaine 10 ml). The level of sensory block, modified Bromage motor scores (MBS), systolic blood pressure and heart rate were recorded for 30 min following anesthesia. Peak sensory block height and MBS, time for sensory regression to L1 and motor recovery to MBS 1, side effects and operator's satisfaction were noted.

The levels of peak sensory block were similar among the groups (P > 0.05). For the SE2 group, the regression to the L1 dermatome was faster (P = 0.004) and the maximum MBS was lower (P = 0.001) than that of the other two groups. Motor block recovery to MBS 1 was faster for the SE1 and SE2 groups than for the S group (P < 0.001). The operator's satisfaction scores of the SE2 group were lower than those of the other two groups (P = 0.019).

During combined spinal-epidural anesthesia, 7.5 mg of spinal bupivacaine and epidural 1.5% lidocaine 10 ml produced faster motor recovery than did 10 mg of spinal bupivacaine in patients undergoing lower extremity surgeries.