Regional anesthesia and pain medicine
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Reg Anesth Pain Med · Jul 2005
Randomized Controlled Trial Comparative Study Clinical TrialA comparison of four stimulation patterns in axillary block.
Insufficient spread of the local anesthetic toward the retroarterial region of the neurovascular space may be responsible for inconsistent anesthesia of the upper limb after single-injection axillary block. We hypothesized that injection of the local anesthetic on a single radial-nerve stimulation would produce the same extent of anesthesia as either a single median-nerve stimulation, a double-stimulation technique (radial and musculocutaneous nerves), or a triple-stimulation technique (radial, musculocutaneous, and median nerves). ⋯ Musculocutaneous-nerve stimulation and radial-nerve stimulation play predominant roles in the success of axillary brachial plexus block, although a triple-nerve stimulation technique is still required to produce complete anesthesia of the upper limb.
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Reg Anesth Pain Med · Jul 2005
Multicenter StudyClinical evaluation of the lateral sagittal infraclavicular block developed by MRI studies.
Lateral sagittal infraclavicular block by single injection has a faster performance time and causes less discomfort than does axillary block by multiple injections. This prospective, descriptive, multicenter study assessed block effectiveness, onset time, and incidence of adverse events and verified the noninvasive measurements from magnetic resonance imaging (MRI). ⋯ Block effectiveness (91%) and onset time (20 minutes) were satisfactory and comparable to the vertical paracoracoid approach. The low rate of axillary vessel punctures (2%) may be the most important advantage of this block. The needle insertion depth measurements confirmed the MRI findings, but the dorsal angle was steeper than predicted.
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Reg Anesth Pain Med · Jul 2005
Plasma concentrations and analgesic effects of ropivacaine 3.75 mg/ml during long-term extrapleural analgesia after thoracotomy.
Fourteen patients received long-term extrapleural analgesia with ropivacaine for postoperative pain relief after posterolateral thoracotomy. We determined plasma concentrations of ropivacaine as well as pain scores and opioid consumption to assess the analgesic effect. ⋯ A dose of 0.375 mg/kg/h of ropivacaine can safely be administered for long-term extrapleural analgesia after thoracotomy.
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Reg Anesth Pain Med · Jul 2005
Differential block of N-propyl derivatives of amitriptyline and doxepin for sciatic nerve block in rats.
The propyl group of ropivacaine ( N -propyl-2',6'-pipecoloxylidide hydrochloride) could be responsible for conferring some sensory selectivity to this drug. Thus, adding a propyl group to experimental local anesthetics (LAs) (e.g., the tricyclic antidepressants amitriptyline and doxepin) to increase sensory selectivity may be useful. We, therefore, synthesized N -propyl amitriptyline and N -propyl doxepin and investigated a potential predominance of sensory/nociceptive block over motor block (differential block) in a rat sciatic nerve block model. In addition, tetrodotoxin (TTX), a naturally occuring Na + channel blocker, was coinjected to investigate whether it increased block duration. ⋯ Detailed histopathologic nerve toxicity evaluations are justified to determine whether N -propyl amitriptyline has potential as a more sensory-selective local anesthetic at lower concentrations or as a predominantly sensory-selective neurolytic agent at higher concentrations.
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Reg Anesth Pain Med · Jul 2005
Morphologic analysis of bipolar radiofrequency lesions: implications for treatment of the sacroiliac joint.
Sacroiliac (SI) joint dysfunction is an important cause of mechanical low-back pain. Bipolar radiofrequency ablation has been proposed as a long-lasting treatment for pain in patients with SI dysfunction who report temporary pain relief with local-anesthetic injection into the joint. No data are available to guide the technical aspects of bipolar radiofrequency lesion creation. This study documents the optimal spacing of cannulae and time required to produce bipolar lesions by use of radiofrequency technology. ⋯ Bipolar radiofrequency treatment creates continuous "strip" lesions proportional in size to the distance between the probes when the distance between cannulae is 6 mm or less. Spacing the cannulae 4 to 6 mm apart and treating at 90 degrees C for 120 to 150 seconds maximizes the surface area of the lesion.