title: The effects of lidocaine used in sciatic nerve on the pharmacodynamics and pharmacokinetics of ropivacaine in sciatic nerve combined with lumbar plexus blockade: a double-blind, randomized study.
abstract: In this controlled, randomized, double-blind study, we compared the pharmacodynamics and pharmacokinetics of ropivacaine and staged injection of lidocaine and ropivacaine in a combined lumbar plexus-sciatic nerve block. The experiment was performed in two parts: pharmacodynamics study (Group r, n = 20; Group lr, n = 20) and pharmacokinetics study (Group R, n = 10; Group LR, n = 10). The sciatic nerve blockade was performed using either (1) 10 mL of 2% lidocaine and then 10 mL of 0.75% ropivacaine (Group lr and Group LR) or (2) 10 mL of normal saline (N.S.) and then 10 mL of 0.75% ropivacaine (Group r and Group R). Two kinds of solutions were 'staged' injection. The sensory onset time and sensory recovery time were assessed in the pharmacodynamics study. Arterial blood samples were collected for the pharmacokinetics study. Sciatic sensory block onset times were reduced, and the sensory recovery times were decreased in Group lr. C(max) of ropivacaine in Group LR was significantly higher than that in Group R. A significant increase in AUC((0-t)) and AUC((0-∞)) was observed in Group LR compared with Group R. When 2% lidocaine and 0.75% ropivacaine are used for a combined sciatic nerve-lumbar plexus block by 'staged' injection, lidocaine induced faster onset times, decreased the block duration and increased the AUC and C(max) of ropivacaine.
authors.affiliation: Department of Anesthesiology, First Affiliated Hospital of Wenzhou Medical College, Zhejiang, China.
authors.forename: Limei
authors.initials: L
authors.lastname: Chen
authors.forename: Quanguang
authors.initials: Q
authors.lastname: Wang
authors.forename: Kejian
authors.initials: K
authors.lastname: Shi
authors.forename: Fuli
authors.initials: F
authors.lastname: Liu
authors.forename: Le
authors.initials: L
authors.lastname: Liu
authors.forename: Jianwu
authors.initials: J
authors.lastname: Ni
authors.forename: Xiangyu
authors.initials: X
authors.lastname: Fang
authors.forename: Xuzhong
authors.initials: X
authors.lastname: Xu
mesh_terms: D000293:Adolescent; D000328:Adult; D000577:Amides / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology; D000779:Anesthetics, Local / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D004359:Drug Therapy, Combination; D006801:Humans; D008012:Lidocaine / Q000008:administration & dosage / Q000494:pharmacology*; D008160:Lumbosacral Plexus / Q000187:drug effects / Q000378:metabolism; D008875:Middle Aged; D009407:Nerve Block / Q000379:methods*; D000077212:Ropivacaine; D012584:Sciatic Nerve / Q000187:drug effects* / Q000378:metabolism; D013997:Time Factors; D055815:Young Adult
chemical_list: D000577:Amides; D000779:Anesthetics, Local; D000077212:Ropivacaine; D008012:Lidocaine