Regional anesthesia and pain medicine
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Reg Anesth Pain Med · Sep 2012
ReviewThe definition of block "success" in the contemporary literature: are we speaking the same language?
A successful nerve block is the common goal that shapes modern regional anesthesia practice and research, yet the meaning of block "success" can be open to interpretation. For this Special Article, we reviewed all applicable randomized controlled trials published over the last decade to determine the most commonly used definitions of block success. We also sought to uncover which relevant indicators of block success are routinely reported in the contemporary literature. ⋯ Surgeon- and hospital administrator-related indicators were not collected in any trial. We found that the definition of block success is highly variable in the contemporary regional anesthesia literature. Our findings underscore the clear and present need for a comprehensive definition of block success, whereas future research should endeavor to capture the indicators of block success that are important to all key perioperative stakeholders.
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Reg Anesth Pain Med · Sep 2012
ReviewRegional anesthesia and analgesia in critically ill patients: a systematic review.
Regional anesthesia has become invaluable for the treatment of pain during and after a wide range of surgical procedures. However, its benefits in the nonsurgical setting have been less well studied. ⋯ Patients in the critical care unit present special challenges to the regional anesthesiologist, including coagulopathies, infections, immunocompromised states, sedation- and ventilation-associated problems, and factors potentially increasing the risk for systemic toxicity. This review is intended to evaluate the role of regional anesthesia in critically ill patients, to discuss potential benefits, and to provide a summary of the published evidence on the subject.
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Reg Anesth Pain Med · Sep 2012
Ultrasound-guided ankle block for forefoot surgery: the contribution of the saphenous nerve.
Ankle blocks typically include the block of 5 nerves, the 4 branches that trace their origin back to the sciatic nerve plus the saphenous nerve (SaN). The sensory area of the SaN in the foot is variable. Based on our clinical experience, we decided to study the sensory distribution of the SaN in the foot and determine whether the block of this nerve is necessary as a component of an ultrasound-guided ankle block for bunion surgery. ⋯ Ultrasound-guided ankle block is a highly effective technique for bunion surgery. The sensory territory of the SaN in the foot seems to extend only to the midfoot. According to our sample, 97% of the patients undergoing bunion surgery under an ankle block would not benefit from having a SaN block.
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Reg Anesth Pain Med · Sep 2012
Duration and local toxicity of sciatic nerve blockade with coinjected site 1 sodium-channel blockers and quaternary lidocaine derivatives.
Quaternary lidocaine derivatives (QLDs) have recently received much attention because of their potential application in prolonged or sensory-selective local anesthesia. However, associated tissue toxicity is an impeding factor that makes QLDs unfavorable for clinical use. Based on the proposed intracellular site of action, we hypothesized that nerve blocks obtained from lower concentrations of QLDs would be enhanced by the coapplication of extracellularly acting site 1 sodium-channel blocker, resulting in prolonged block duration but with minimal tissue toxicity. ⋯ Coadministration of site 1 sodium-channel blockers and QLDs greatly prolongs the duration of peripheral nerve block without enhancing local tissue injury, but minimal myotoxicity still persists. It is not clear that the risks of QLDs are outweighed by the benefits in providing prolonged nerve blockade.
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Reg Anesth Pain Med · Sep 2012
Intrathecal oxytocin inhibits visceromotor reflex and spinal neuronal responses to noxious distention of the rat urinary bladder.
Oxytocin (OXY) is a neuropeptide that has recently been recognized as an important component of descending analgesic systems. The present study sought to determine if OXY produces antinociception to noxious visceral stimulation. ⋯ These results argue that intrathecal OXY produces an OXY receptor-specific antinociception to noxious UBD, with part of this effect due to inhibition of spinal dorsal horn neurons. To our knowledge, these studies provide the first evidence that intrathecal OXY may be an effective pharmacological treatment for visceral pain.