Anesthesia and analgesia
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Anesthesia and analgesia · Dec 2006
Use of magnetic resonance imaging to define the anatomical location closest to all three cords of the infraclavicular brachial plexus.
Infraclavicular techniques are often used to perform brachial plexus blocks. In our volunteer study we used magnetic resonance imaging to identify the brachial plexus and axillary vessels in a sagittal plane corresponding to the lateral sagittal infraclavicular block. ⋯ We conclude that this knowledge may be useful for the performance of infraclavicular blocks aided by ultrasound. However, our proposals should be tested by clinical studies.
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Anesthesia and analgesia · Dec 2006
Holiday and weekend operating room on-call staffing requirements.
Every facility that performs cases on holidays has in some way decided on its operating room (OR) and anesthesia staffing for holidays. Previous studies have not examined how best to calculate appropriate holiday staffing. ⋯ The number of cases starting during each period of a holiday is a statistically valid end point for OR managers to use to evaluate how busy holidays are relative to weekend days. To be useful, the statistic must be combined with mathematically valid assessments of appropriate weekend staffing on-call, whether in-house, or from home.
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Anesthesia and analgesia · Dec 2006
The differential effects of nitrous oxide and xenon on extracellular dopamine levels in the rat nucleus accumbens: a microdialysis study.
Dopamine release in the nucleus accumbens (NAC) plays a crucial role in the action of various psychotropic and addictive drugs, such as antagonists of the N-methyl-D-aspartate subtype of the glutamate. Although both nitrous oxide and xenon are N-methyl-D-aspartate receptor antagonists, they differ in their potential for producing neuropsychological toxicity; therefore, we decided to examine their effects on both spontaneous and ketamine-induced extracellular dopamine levels in the NAC. A microdialysis probe was implanted into the NAC in each of 35 rats, which were randomly assigned to one of six groups: exposure to 40% O2, exposure to 60% nitrous oxide (0.27 MAC), exposure to 43% xenon (0.27 MAC) for 60 min, and three groups exposed to either 40% O2, 60% nitrous oxide, or 43% xenon for 70 min and 80 mg/kg ketamine was given i.p. 10 min after the initiation of gas exposure. ⋯ Nitrous oxide, but not xenon, significantly increased the dopamine level. Ketamine significantly increased the dopamine level, and this was significantly inhibited by xenon, but not by nitrous oxide. These data suggest that the difference in neuropsychological activity between nitrous oxide and xenon is partly due to their differential effects on the mesolimbic dopamine system.
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Anesthesia and analgesia · Dec 2006
The effect of electroencephalogram-targeted high- and low-dose propofol infusion on histopathological damage after traumatic brain injury in the rat.
Propofol is commonly used to sedate patients after traumatic brain injury. However, the dose-dependent neuroprotective effects of propofol after head trauma are unknown. We compared histopathological damage after 6 h of electroencephalogram-targeted high- and low-dose propofol infusion in rats subjected to controlled cortical impact (CCI). ⋯ Despite different levels of cortical neuronal function, there were no relevant differences in the short-term histopathological damage. These results challenge the view that the neuroprotective effect of propofol relates to the suppression of cerebral metabolic demand.