Feasibility study of continuous spinal anesthesia for lower limb joint replacement in elderly patients with hypobaric ropivacaine and evobupivacaine

Objective To investigate the feasibility and safety of continuous spinal anesthesia for lower limb joint replacement in elderly patients with hypobaric ropivacaine and levobupivacaine.Methods Sixty elderly patients(ASA Ⅰ～Ⅲ) scheduled for lower limb joint replacement with continuous spinal anesthesia were randomly divided into group R and group L equally. Patients in group R received 0.3 hypobaric ropivacaine 4 ml by spinal anesthesia and patients in group B received 0.3 hypobaric levobupivacaine 4 ml by spinal anesthesia. Onset time of sensory block, upper sensory level, time to maximal degree of motor block, duration of analgesia and regression of Bromage 0 were investigated.Mean arterial pressure, heart rate, respiratory rate, oxygen saturation,consumption of local anesthetics and side effects were recorded.Results Onset of sensory block and motor block were slower in group R than those in group L(P0.01);Upper sensory level at the side of surgery in the two groups was higher than another side (P0.001);Duration of analgesia and motor recovery were shorter in group R than those in group L(P0.01);The ratio of Bromage 2 and Bromage 3 was lower in group R than that in group L(P0.05);Consumption of local anesthetics was more in group R than group L(P0.01).There were no significant hemodynamic changes in the two groups compared with baseline values (P0.05);The incidenxes of side effects during and after operation were low and there were no significant differences between the two groups. (P0.05).Conclusion Continuous spinal anesthesia with hypobaric ropivacaine and levobupivacaine is safe and effective for lower limb joint replacement in elderly patients.