Regional anesthesia and pain medicine
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Reg Anesth Pain Med · Sep 2011
Review Case Reports Comparative StudyStroke, regional anesthesia in the sitting position, and hypotension: a review of 4169 ambulatory surgery patients.
Despite frequent incidence of hypotension, no cases of stroke were observed in this audit of 4,169 shoulder surgeries performed in the beach-chair position. Notably though, 97% of the cases were performed under brachial plexus block with intravenous sedation rather than a general or relaxant technique.
The authors estimate the upper limit incidence of stroke in the sitting position under regional anaesthesia as 1 in 1,429 (0.07%).
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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 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
Case ReportsRetained stimulating perineural catheters: a report of four cases.
As the use of ambulatory continuous peripheral nerve blocks continues to grow, new management issues will inevitably arise. Previous descriptions of difficult catheter removal due to cutting, knotting, or kinking of the catheter have involved inpatients. A series of retained ambulatory interscalene catheters has recently been reported. ⋯ Stimulating perineural catheters may be difficult to remove. This may be particularly problematic for outpatients removing the catheters at home.