Anesthesiology
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Randomized Controlled Trial
Detection of consciousness by electroencephalogram and auditory evoked potentials.
A set of electroencephalographic and auditory evoked potential (AEP) parameters should be identified that allows separation of consciousness from unconsciousness (reflected by responsiveness/unresponsiveness to command). ⋯ A combination of electroencephalographic and AEP parameters can be used to differentiate between consciousness and unconsciousness even in a very challenging data set. The minimal model contains a combination of AEP and electroencephalographic parameters and has a higher prediction probability than Bispectral Index for the separation between consciousness and unconsciousness.
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Volatile anesthetics attenuate apoptosis. The underlying mechanisms remain undefined. The authors tested whether isoflurane reduces apoptosis in cardiomyocytes subjected to oxidative or inflammatory stress by enhancing Akt and B-cell lymphoma-2 (Bcl-2). ⋯ Isoflurane protects cardiomyocytes against apoptosis induced by hypoxia, H2O2, or activated neutrophils through Akt activation and increased Bcl-2 expression. This suggests that a reduction in apoptosis contributes to the cardioprotective effects of isoflurane.
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Dexmedetomidine is a potent and selective alpha2-adrenoceptor agonist that exhibits a broad pattern of actions, including sedation, analgesia, and neuroprotection. Some of these actions (e.g., neuroprotection) may require targets involved in long-term cellular changes. The authors hypothesized that dexmedetomidine increases the expression of active (autophosphorylated) focal adhesion kinase (FAK), a nonreceptor tyrosine kinase playing a pivotal role in cellular plasticity and survival. Therefore, we examined the cellular mechanisms involved in this effect and its sensitivity to oxygen-glucose deprivation (OGD) in rat hippocampal slices. ⋯ Dexmedetomidine exhibits a preconditioning effect against ischemic injury in hippocampal slices subjected to OGD. Increase in phosphorylation of FAK via stimulation of alpha2 adrenoceptors and decrease in cleaved caspase-3 expression correlate with dexmedetomidine-induced cell survival.
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Resiniferatoxin is a potent capsaicin analog. Intrathecal administration leads to selective, prolonged opening of the transient receptor potential V1 ion channel, which is localized mainly to C-fiber primary afferent nociceptive sensory neurons. Following work in laboratory animals, the authors explored the use of intrathecal resiniferatoxin to control spontaneous bone cancer pain in companion (pet) dogs. ⋯ Intrathecal resiniferatoxin elicits transient hemodynamic effects. In controls, a profound and sustained blockade of thermal stimuli is produced in a dose-dependent fashion. Similar administration in dogs with bone cancer produces a prolonged antinociceptive response.