Articles: nerve-block.
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Acta Anaesthesiol Scand · Sep 2001
Evidence that spinal segmental nitric oxide mediates tachyphylaxis to peripheral local anesthetic nerve block.
Tachyphylaxis to sciatic nerve blockade in rats correlates with hyperalgesia. Spinal inhibition of nitric oxide synthase with N(G)nitro-L-arginine methyl ester (L-NAME) has been shown to prevent hyperalgesia. Given systemically, L-NAME also prevents tachyphylaxis. The action of L-NAME in preventing tachyphylaxis therefore may be mediated at spinal sites. We compared systemic versus intrathecal potency of L-NAME in modulating tachyphylaxis to sciatic nerve block. ⋯ The increased potency of intrathecal versus systemic L-NAME suggests a spinal site of action in inhibiting tachyphylaxis. Descending pathways are not necessary for the development of tachyphylaxis since it occurs even after T10 spinal cord transection. Thus tachyphylaxis, like hyperalgesia, is mediated at least in part by a spinal site of action.
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Minerva anestesiologica · Sep 2001
Randomized Controlled Trial Comparative Study Clinical Trial[Cervical plexus block and continuous cervical peridural block with ropivacaine for carotid surgery: a comparison between the 2 methods].
To evaluate the efficacy and security of the cervical plexus block and the continuous cervical peridural anaesthesia in carotid surgery, using ropivacaine as local anaesthetic. ⋯ cervical plexus block and continuous cervical peridural anaesthesia performed with ropivacaine are both effective for anaesthesia in carotid surgery. Ropivacaine, for its minor cardiotoxicity, yields eventual complications related to the two methods, less severe.
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Reg Anesth Pain Med · Sep 2001
Randomized Controlled Trial Clinical TrialAnalgesic effects of low-dose ropivacaine for interscalene brachial plexus block for outpatient shoulder surgery-a dose-finding study.
Interscalene brachial plexus block (ISB) with low-dose bupivacaine provides effective postoperative shoulder analgesia in outpatients. The analgesic effect of low-dose ropivacaine for ISB is unknown. ⋯ Interscalene brachial plexus block with low-dose ropivacaine, 10 mL of 0.25% and 0.5%, provides effective long-lasting shoulder analgesia in a majority of patients after arthroscopic surgery.
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Reg Anesth Pain Med · Sep 2001
Randomized Controlled Trial Clinical TrialEffect of impulse duration on patients' perception of electrical stimulation and block effectiveness during axillary block in unsedated ambulatory patients.
Chronaxie of the motor-neurons (A-alpha) is shorter than that of the sensory A-delta and C neurons. Therefore, a short current impulse should elicit a painless muscle twitch. This randomized, double-blind study of patients having ambulatory axillary block by multiple neurostimulations compared patients' perception of electrical stimulation, latency, and quality of analgesia and the incidence of adverse effects. ⋯ This study did not confirm our hypothesis that short-current impulses (0.1 ms) make neurostimulation of peripheral nerves painless, by selectively depolarizing motor-neurons. Longer impulses (0.3 ms) shorten block performance time, probably by easier location of the nerves, but the clinical relevance of this finding is doubtful.
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Reg Anesth Pain Med · Sep 2001
Randomized Controlled Trial Clinical TrialAddition of fentanyl to bupivacaine prolongs anesthesia and analgesia in axillary brachial plexus block.
To evaluate the analgesic and anesthetic effects of 40 mL bupivacaine 0.25%, 40 mL bupivacaine 0.25% plus fentanyl 2.5 microg/mL, and 40 mL bupivacaine 0.125% plus fentanyl 2.5 microg/mL for axillary brachial plexus block. ⋯ The addition of 100 microg/mL fentanyl to 0.25% bupivacaine almost doubles the duration of analgesia following axillary brachial plexus block when compared with 0.25% bupivacaine alone.