Regional anesthesia and pain medicine
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Reg Anesth Pain Med · Nov 2014
Perineural Hematoma May Result in Nerve Inflammation and Myelin Damage.
Perineural hematoma may occur during performance of peripheral nerve blocks. The aim of this study was to test the hypothesis that an iatrogenic hematoma in the immediate vicinity of a peripheral nerve may cause histologic evidence of nerve injury. ⋯ Our data suggest that hematoma adjacent to nerve tissue may result in structural nerve injury and inflammatory changes.
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Reg Anesth Pain Med · Nov 2014
Evaluation of Epidural and Peripheral Nerve Catheter Heating During Magnetic Resonance Imaging.
Many epidural and peripheral nerve catheters contain conducting wire that could heat during magnetic resonance imaging (MRI), requiring removal for scanning. ⋯ Most but not all catheters can be left in place during 1.5-T MRI scans. Heating of less than 3°C during MRI for most catheters is not expected to be injurious. While heating was lower at 1.5 T versus 3 T, performance differences between products underscore the need for safety testing before performing MRI.
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Reg Anesth Pain Med · Nov 2014
Mechanisms Underlying Midazolam-Induced Peripheral Nerve Block and Neurotoxicity.
The benzodiazepine midazolam has been reported to facilitate the actions of spinally administrated local anesthetics. Interestingly, despite the lack of convincing evidence for the presence of γ-aminobutyric acid type A (GABAA) receptors along peripheral nerve axons, midazolam also has been shown to have analgesic efficacy when applied alone to peripheral nerves.These observations suggest midazolam-induced nerve block is due to another site of action. Furthermore, because of evidence indicating that midazolam has equal potency at the benzodiazepine site on the GABAA receptor and the 18-kd translocator protein (TSPO), it is possible that at least the nerve-blocking actions of midazolam are mediated by this alternative site of action. ⋯ Our results indicate that processes underlying midazolam-induced nerve block and neurotoxicity are separable, and suggest that selective activation of TSPO may facilitate modality-selective nerve block while minimizing the potential for neurotoxicity.