Regional anesthesia and pain medicine
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Reg Anesth Pain Med · Sep 2011
Comparative StudyGlutamate release and neurologic impairment after intrathecal administration of lidocaine and bupivacaine in the rat.
Local anesthetic-induced neurotoxicity is one of the potential causes of postspinal anesthesia neurologic injury. Many experimental and clinical studies have demonstrated that lidocaine is more neurotoxic than bupivacaine. The mechanisms of local anesthetic-induced neurotoxicity remain unclear. Glutamate is an excitatory amino acid and widely exists in the central nervous system. Overstimulation of the glutamate receptors may produce neuronal toxic effect. In this study, we used in vivo microdialysis to examine the glutamate release in cerebrospinal fluid (CSF) after intrathecal lidocaine and bupivacaine injection. ⋯ Intrathecal lidocaine caused a concentration-dependent increase of the CSF glutamate release and postinjection neurologic impairment; these effects can be reversed by MK-801. However, intrathecal bupivacaine shows no influence. We suggest that glutamate may be involved in the pathogenesis of lidocaine-induced spinal neurotoxicity.
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Reg Anesth Pain Med · Sep 2011
Comparative StudyThe influence of adjuvants used in regional anesthesia on lidocaine-induced neurotoxicity in vitro.
Neurotoxic properties of local anesthetics can rarely lead to irreversible neuronal damage as in cauda equina syndrome. Clinically, local anesthetics are often combined with adjuvants to improve or prolong the anesthetic effect, whereas the impact of such adjuvants on lidocaine-induced apoptosis is unclear. Therefore, we investigated the influence of different adjuvants on the neurotoxicity of lidocaine. ⋯ Sufentanil, clonidine, epinephrine, and neostigmine do not influence the neurotoxicity of lidocaine in vitro. Morphine may have some cytoprotective effect at concentrations greater than those seen intrathecally in humans. In contrast, ketamine and midazolam increase the neurotoxicity of lidocaine in vitro, presumably by additive induction of mitochondrial apoptosis.
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Reg Anesth Pain Med · Sep 2011
Randomized Controlled Trial Multicenter Study Comparative StudyIntraoperative local infiltration analgesia for early analgesia after total hip arthroplasty: a randomized, double-blind, placebo-controlled trial.
High-volume local infiltration analgesia (LIA) is widely applied as part of a multimodal pain management strategy in total hip arthroplasty (THA). However, methodological problems hinder the exact interpretation of previous trials, and the evidence for LIA in THA remains to be clarified. Therefore, we evaluated whether intraoperative high-volume LIA, in addition to a multimodal oral analgesic regimen, would further reduce acute postoperative pain after THA. ⋯ Intraoperative high-volume LIA with ropivacaine 0.2% provided no additional reduction in acute pain after THA when combined with a multimodal oral analgesic regimen consisting of acetaminophen, celecoxib, and gabapentin and is therefore not recommended.
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Reg Anesth Pain Med · Sep 2011
Randomized Controlled Trial Comparative StudyCatheter orifice configuration influences the effectiveness of continuous peripheral nerve blockade.
We investigated perineural catheter threading distance and orifice configuration during continuous interscalene analgesia. ⋯ These results suggest that multiorifice catheters provide superior intermittent bolus continuous peripheral nerve blockade compared with end-hole catheters. For anterolateral approach interscalene catheter placement, there is minimal benefit, either way, to 2.5- or 5-cm blind catheter advancement.
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Reg Anesth Pain Med · Sep 2011
Comparative StudyHigh-resolution ultrasound accurately identifies the medial antebrachial cutaneous nerve at the midarm level: a clinical anatomic study.
The present prospective volunteer study was designed to describe a technique for ultrasound identification of the medial antebrachial cutaneous nerve (MACN) and a technique for ultrasound-guided blockade of this sensory nerve of the upper limb. ⋯ The results of this investigation enable selective blockade of the MACN via ultrasound. Moreover, our data provide insight regarding the specific anatomic course and the integrity of this sensory nerve, which could be used for plastic and reconstructive surgical indications and for diagnosis of nerve injury.