Regional anesthesia and pain medicine
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Reg Anesth Pain Med · Jan 2013
The κ-opioid receptor agonist U-50488 blocks Ca2+ channels in a voltage- and G protein-independent manner in sensory neurons.
κ-Opioid receptor (κ-OR) activation is known to play a role in analgesia and central sedation. The purpose of the present study was to examine the effect of the κ-OR agonist, U-50488 (an arylacetamide), on Ca channel currents and the signaling proteins involved in acutely isolated rat dorsal root ganglion (DRG) neurons expressing the putative promoter region of the tetrodotoxin-resistant Na channel (NaV 1.8) that is known to be involved in pain transmission. ⋯ These results suggest that the antinociceptive actions mediated by U-50488 are likely due to both a direct block of Ca channels in sensory neurons as well as G protein modulation of Ca currents via κ-OR-expressing neurons.
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Reg Anesth Pain Med · Jan 2013
Outcomes of shoulder surgery in the sitting position with interscalene nerve block: a single-center series.
Several case reports have raised serious concerns about the safety of shoulder surgery in the beach-chair position, related to global cerebral hypoperfusion. We summarize our experiences with 15,014 cases of shoulder arthroscopy over an 11-year period. Our primary aim was to evaluate the incidence of intraoperative or immediate postoperative neurologic events and secondarily to relate other perioperative complications. ⋯ This retrospective study suggests that intraoperative or immediate postoperative stroke is rare when surgery is conducted in beach-chair position in conjunction with regional anesthesia, propofol sedation, and spontaneous respiration via natural airway.
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Reg Anesth Pain Med · Jan 2013
Case ReportsRespiratory impact of analgesic strategies for shoulder surgery.
Shoulder surgery is associated with significant postoperative pain in many patients. The use of an interscalene nerve block offers good analgesia but is associated with a high incidence of an ipsilateral phrenic nerve block. ⋯ Possible strategies are (1) using very low volumes of local anesthetics, (2) targeting the brachial plexus at a lower level in the neck, (3) applying a suprascapular nerve block, and (4) applying the combination of a suprascapular and an axillary nerve block. Using systemic analgesics is a less favorable strategy because this may result in less potent analgesia and may cause more adverse effects, including respiratory depression and nausea.