腰丛与坐骨神经联合阻滞：罗哌卡因血浆浓度分析

Combined lumbar-plexus and sciatic-nerve blocks: an analysis of plasma ropivacaine concentrations.

作者信息

Vanterpool Stephanie, Steele Susan M, Nielsen Karen C, Tucker Marcy, Klein Stephen M

机构信息

School of Medicine, Duke University Medical Center, Durham, NC 27710, USA.

出版信息

Reg Anesth Pain Med. 2006 Sep-Oct;31(5):417-21. doi: 10.1016/j.rapm.2006.06.007.

DOI:10.1016/j.rapm.2006.06.007

PMID:16952812

Abstract

BACKGROUND AND OBJECTIVES

Lumbar-plexus and sciatic-nerve blocks are commonly combined for lower-extremity anesthesia using large doses of ropivacaine. Limited information is available about the pharmacokinetics of this practice. We analyzed plasma ropivacaine concentrations after single-injection lumbar-plexus blocks with and without sciatic-nerve blocks.

METHODS

Twenty patients having lower-extremity surgery using a lumbar-plexus block with 0.5% ropivacaine with 1:400,000 epinephrine (35 mL, n = 10) or the same lumbar-plexus block with the addition of a sciatic-nerve block (25 mL, n = 10, 60 mL total) using the same solution were enrolled. Venous blood samples were collected at 5, 15, 30, 45, 60, 120, and 240 minutes after block placement and analyzed for total ropivacaine concentration by use of gas chromatography. Individual timepoints, maximum concentrations (C(max)), and time to C(max) (T(max)) were compared. Values are mean +/- SD.

RESULTS

Both groups demonstrated a rapid increase in plasma concentration over the first 30 to 45 minutes. Concentrations were greater for those who received both blocks (P = .0005) at all timepoints. The lumbar-plexus block C(max) was less (986 +/- 221 ng/mL) than for the combined blocks (1,560 +/- 351 ng/mL, P = .0004). The T(max) was greater for the lumbar plexus (80 +/- 49 min) than for the combined blocks (38 +/- 22 min, P = .03). There was no relationship between the C(max) and patient age, weight, or body mass index.

CONCLUSIONS

The results of this study demonstrate that the plasma ropivacaine concentrations increase quicker when a sciatic-nerve block is added to a lumbar-plexus block, but C(max) remains below the toxicity threshold.

摘要

背景与目的

腰丛神经阻滞和坐骨神经阻滞常联合使用大剂量罗哌卡因用于下肢麻醉。关于这种联合用药的药代动力学信息有限。我们分析了单纯腰丛神经阻滞以及联合坐骨神经阻滞单次注射后血浆罗哌卡因浓度。

方法

选取20例接受下肢手术的患者，其中10例采用含1:400,000肾上腺素的0.5%罗哌卡因进行腰丛神经阻滞（35 mL），另外10例采用相同溶液进行腰丛神经阻滞并联合坐骨神经阻滞（25 mL，总量60 mL）。在阻滞操作后5、15、30、45、60、120和240分钟采集静脉血样，采用气相色谱法分析罗哌卡因总浓度。比较各个时间点、最大浓度（C(max)）以及达到C(max)的时间（T(max)）。数据以均数±标准差表示。

结果

两组在最初30至45分钟内血浆浓度均迅速升高。在所有时间点，接受联合阻滞的患者血浆浓度更高（P = 0.0005）。单纯腰丛神经阻滞的C(max)低于联合阻滞（分别为986±221 ng/mL和1560±351 ng/mL，P = 0.0004）。腰丛神经阻滞的T(max)大于联合阻滞（分别为80±49分钟和38±22分钟，P = 0.