Anesthesiology
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Randomized Controlled Trial Comparative Study Clinical Trial
Dexmedetomidine pharmacodynamics: part I: crossover comparison of the respiratory effects of dexmedetomidine and remifentanil in healthy volunteers.
Dexmedetomidine, a highly selective alpha2-adrenoceptor agonist used for short-term sedation of mechanically ventilated patients, has minimal effect on ventilation. ⋯ In comparison with remifentanil, dexmedetomidine infusions (1) did not result in clinically significant respiratory depression, (2) decreased rather than increased the apnea/hypopnea index, and (3) exhibited some similarity with natural sleep.
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Randomized Controlled Trial Clinical Trial
Induction speed is not a determinant of propofol pharmacodynamics.
Evidence suggests that the rate at which intravenous anesthetics are infused may influence their plasma-effect site equilibration. The authors used five different rates of propofol administration to test the hypothesis that different sedation endpoints occur at the same effect site propofol concentration, independent of the infusion rate. The authors concurrently evaluated the automated responsiveness monitor (ARM) against other sedation measures and the propofol effect site concentration. ⋯ : Population-based pharmacokinetics, combined with real-time electroencephalographic measures of drug effect, may provide a means to individualize pharmacodynamic modeling during target-controlled drug delivery. ARM seems useful as an automated measure of sedation and may provide the basis for automated monitoring and titration of sedation for a propofol delivery system.
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A recurring initiative in graduate education is to find more effective methods to assess specialists' skills. Life-sized simulators could be used to assess the more complex skills expected in specialty practice if a curriculum of relevant exercises were developed that could be simply and reliably scored. The purpose of this study was to develop simulation exercises and associated scoring methods and determine whether these scenarios could be used to evaluate acute anesthesia care skills. ⋯ This study suggests that simulation can be used to measure more complex skills expected in specialty training. Similar to other studies that assess a broad content domain, multiple encounters are needed to estimate skill effectively and accurately.
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Preconditioning against myocardial infarction by volatile anesthetics is well known. The authors tested the hypothesis that new emulsified formulations of halogenated anesthetics administered intravenously reduce myocardial infarct size when administered either 1 or 24 h before prolonged ischemia and reperfusion. ⋯ Intravenous emulsified halogenated anesthetics produce acute and delayed preconditioning against myocardial infarction.
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The authors studied the influence of alpha, beta, and dopaminergic catecholamines on blood volume expansion in conscious normovolemic sheep before, during, and after a bolus infusion of a crystalloid. ⋯ Catecholamines can alter the intravascular volume expansion of fluid therapy. beta-Receptor (isoproterenol) stimulation augmented blood volume expansion, whereas alpha (phenylephrine) stimulation reduced blood volume expansion. Combined dopaminergic, beta, and possibly alpha stimulation with dopamine augmented blood volume expansion and cardiac output while inducing diuresis.