Effects of dexmedetomidine plus ropivacanie on lumbar plexus-sciatic nerve blocks and sedation / 临床外科杂志

ABSTRACT

Objective To investigate the effects of dexmedetomidine plus ropivacanie on lumbar plexus-sciatic nerve blocks and sedation. Methods One hundred and twenty patients( ASA Ⅰ-Ⅲ) scheduled for unilateral arthroscopy of the knee received lumbar plexus-sciatic nerve blocks. The patients were randomly divided into 4 groups(n = 30 in each). In group R,dexmedetomidine was not used for nerve. In group RLD,dexmedetomidine was only used for lumbar-plexus block. In group RSD,dexmedeto-midine was only used for sciatic nerve block. In group RD,dexmedetomidine was used for both lumbar-plexus block and sciatic nerve block. Onset time and maximum time of sensory and motor block,duration of analgesia,Ramsay scores,HR,and the incidence of anesthetic toxicity were recorded at different time points(T0-T4). Results There were no significant differences in the onset time of sensory and motor block among the groups(P > 0. 05). However,there were significant differences in the maximum time of sensory and motor block for the lumbar plexus among the RLD group[(1008. 00 ± 104. 99)min and (800. 00 ± 97. 56)min],RD group[(922. 00 ± 149. 05)min and(732. 00 ± 139. 52)min],RSD group [(768. 00 ± 108. 48)min and(602. 00 ± 84. 09)min],and R group[(742. 00 ± 129. 44)min and (612. 00 ± 109. 62)min]. There were significant differences in the maximum time of sensory and motor block for the sciatic nerve among the RLD group[(1006. 00 ± 117. 58)min and(810. 00 ± 105. 41) min],RD group[(932. 00 ± 144. 18)min and(744. 00 ± 136. 09)min],RSD group[(738. 00 ± 120. 16)min and(582. 00 ± 96. 04)min],and R group[(708. 00 ± 126. 45)min and(548. 00 ± 111. 12)min]. Compare with the R group,the Ramsay scores of at the time point of T1-T4 were higher and the HRs were lower in the RLD group,RSD group and RD group. There were significant differences in the analgesia duration among the RLD group[(1006. 00 ± 117. 58)min],RD group[(918. 00 ± 83. 60)min],RSD group[(898. 00 ± 131. 34)min],and R group[(808. 00 ± 119. 72)min]. No local anesthetic intoxication was noticed. Conclusion Perineural dexmedetomidine plus ropivacaine increase the effects of lumbar plexus-sciatic nerve blocks in a dose-dependent manner. Dexmedetomidine provides a good sedative effect,however,it may lead to bradycardia.