Anesthesiology
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Clinical Trial Controlled Clinical Trial
The magnitude and time course of vecuronium potentiation by desflurane versus isoflurane.
Preliminary studies suggest that desflurane and isoflurane potentiate the action of muscle relaxants equally. However, variability between subjects may confound these comparisons. A crossover study was performed in volunteers on the ability of desflurane and isoflurane to potentiate the neuromuscular effect of vecuronium, to influence its duration of action, and on the magnitude and time course of reversal of potentiation when anesthesia was withdrawn. ⋯ Desflurane potentiates the effect of vecuronium approximately 20% more than does an equipotent dose of isoflurane.
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Randomized Controlled Trial Clinical Trial
An evaluation of the effect of anesthetic technique on reproductive success after laparoscopic pronuclear stage transfer. Propofol/nitrous oxide versus isoflurane/nitrous oxide.
Laparoscopic pronuclear stage transfer (PROST) is the preferred method of embryo transfer after in vitro fertilization in many infertility programs. There are scant data to recommend the use or avoidance of any particular anesthetic agent for use in women undergoing this procedure. The authors hypothesized that propofol would be an ideal anesthetic for laparoscopic PROST because of its characteristic favorable recovery profile that includes minimal sedation and a low incidence of postoperative nausea and vomiting. The purpose of the study was to compare propofol and isoflurance with respect to postanesthetic recovery and pregnancy outcomes after laparoscopic PROST. ⋯ Propofol/nitrous oxide anesthesia was associated with lower clinical and ongoing pregnancy rates compared with isoflurane/nitrous oxide anesthesia.
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Clinical Trial Controlled Clinical Trial
Distribution of cerebral blood flow during anesthesia with isoflurane or halothane in humans.
Halothane and isoflurane have been shown to induce disparate effects on different brain structures in animals. In humans, various methods for measuring cerebral blood flow (CBF) have produced results compatible with a redistribution of CBF toward deep brain structures during isoflurane anesthesia in humans. This study was undertaken to examine the effects of halothane and isoflurance on the distribution of CBF. ⋯ There is a difference in the human rCBF distribution between halothane and isoflurane with higher relative flows in subcortical regions during isoflurane anesthesia. However, despite this redistribution, isoflurane anesthesia resulted in a lower mean CBFxenon than did anesthesia with halothane.
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In dogs, sheep, and rats, spinal neostigmine produces analgesia alone and enhances analgesia from alpha 2-adrenergic agonists. This study assesses side effects and analgesia from intrathecal neostigmine in healthy volunteers. ⋯ The incidence and severity of these adverse events from intrathecal neostigmine appears to be affected by dose, method of administration, and baricity of solution. These effects in humans are consistent with studies in animals. Because no unexpected or dangerous side effects occurred, cautious examination of intrathecal neostigmine alone and in combination with other agents for analgesia is warranted.
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Numerous classes of anesthetic agents have been shown to enhance the effects mediated by the postsynaptic gamma-aminobutyric acid A (GABAA) receptor-coupled chloride channel in the mammalian central nervous system. However, presynaptic actions of anesthetics potentially relevant to clinical anesthesia remain to be clarified. Therefore, in this study, the effects of intravenous and volatile anesthetics on both the uptake and the depolarization-evoked release of GABA in the rat striatum were investigated. ⋯ These results indicate that most of the intravenous but not the volatile anesthetics inhibit the specific high-affinity 3H-GABA uptake process in vitro in striatal nerve terminals. However, this action was observed at clinically relevant concentrations only for propofol and etomidate. In contrast, the depolarization-evoked 3H-GABA release was not affected by anesthetics. Together, these data suggest that inhibition of GABA uptake, which results in synaptic GABA accumulation, might contribute to propofol and etomidate anesthesia.