Regional anesthesia and pain medicine
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Reg Anesth Pain Med · Mar 2012
Cervical medial branch block: a novel technique using ultrasound guidance.
Cervical medial branch blocks are commonly performed for the diagnosis and treatment of head, neck, and shoulder pain. Intermittent fluoroscopy is widely used for needle positioning and visualization of contrast distribution before medication injection. The purpose of this study was to examine the use of ultrasound as an alternative imaging technique to block the third occipital nerve and the C3 to C6 medial branches. ⋯ Ultrasound guidance offers a reliable alternative to fluoroscopy for third occipital nerve and C3-C6 cervical medial branch blocks. Further studies are required to validate the clinical efficacy of our technique.
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Reg Anesth Pain Med · Mar 2012
Respiratory, neuromuscular, and cardiovascular effects of neosaxitoxin in isoflurane-anesthetized sheep.
Neosaxitoxin (NeoSTX) is a potent site-1 sodium-channel blocker being developed as a local anesthetic. Doses of 100 μg have been used by local infiltration in anesthetized adult humans without adverse effect. We hypothesized that similar doses could cause significant respiratory, neuromuscular, and cardiovascular impairment and sought to test this hypothesis in sheep. ⋯ In our sheep model, neuromuscular, respiratory, and cardiovascular effects of NeoSTX were dose dependent and mild using the dose range anticipated for clinical use.
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Reg Anesth Pain Med · Mar 2012
The use of dye surrogates to illustrate local anesthetic drug sequestration by lipid emulsion: a visual demonstration of the lipid sink effect.
We hypothesized that by substituting a dye surrogate in place of local anesthetic, we could visually demonstrate dye sequestration by lipid emulsion that would be dependent on both dye lipophilicity and the amount of lipid emulsion used. ⋯ Our study provides a visual demonstration of the lipid sink effect. It supports the theory that lipid emulsion may reduce the amount of free drug present in plasma from concentrations associated with an invariably fatal outcome to those that are potentially survivable.
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Ultrasound guidance has led a surge of interest in transversus abdominis plane (TAP) block for postoperative analgesia following abdominal surgery. Despite or because of the numerous descriptive applications and techniques that have recently populated the literature, results of comparative studies for TAP block have been inconsistent. This systematic review pragmatically addresses many unanswered questions, specifically the following: what are the effects of surgical procedure, block dose, block technique, and block timing on TAP block analgesia? Eighteen intermediate- to good-quality randomized trials that included diverse surgical procedures were identified. ⋯ Eight of 9 trials using preincisional TAP block and 4 of 9 with postincisional block revealed better analgesic outcomes. Although the majority of trials reviewed suggest superior early pain control, we were unable to definitively identify the surgical procedures, dosing, techniques, and timing that provide optimal analgesia following TAP block. This review suggests that our understanding of the TAP block and its role in contemporary practice remains limited.