Anesthesiology
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Neurocognitive dysfunction is a common complication of cardiac surgery using cardiopulmonary bypass (CPB). Elucidating injury mechanisms and developing neuroprotective strategies have been hampered by the lack of a suitable long-term recovery model of CPB. The purpose of this study was to investigate neurologic and neurocognitive outcome after CPB in a recovery model of CPB in the rat. ⋯ CPB caused both neurologic and neurocognitive impairment in a rodent recovery model. This model could potentially facilitate the investigation of CPB-related injury mechanisms and possible neuroprotective interventions.
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The general anesthetic ketamine is known to be an N-methyl-D-aspartate receptor blocker. Although ketamine also blocks voltage-gated sodium channels in a local anesthetic-like fashion, little information exists on the molecular pharmacology of this interaction. We measured the effects of ketamine on sodium channels. ⋯ Ketamine interacts with sodium channels in a local anesthetic-like fashion, including sharing a binding site with commonly used clinical local anesthetics.
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Comparative Study
Widespread inhibition of sodium channel-dependent glutamate release from isolated nerve terminals by isoflurane and propofol.
Controversy persists concerning the mechanisms and role of general anesthetic inhibition of glutamate release from nerve endings. To determine the generality of this effect and to control for methodologic differences between previous studies, the authors analyzed the presynaptic effects of isoflurane and propofol on glutamate release from nerve terminals isolated from several species and brain regions. ⋯ Isoflurane and propofol inhibited Na+ channel-mediated glutamate release evoked by veratridine with greater potency than release evoked by increased KCl in synaptosomes prepared from three mammalian species and three rat brain regions. These findings are consistent with a greater sensitivity to anesthetics of presynaptic Na+ channels than of Ca2+ channels coupled to glutamate release. This widespread presynaptic action of general anesthetics is not mediated by potentiation of gamma-aminobutyric acid type A receptors, though additional mechanisms may be involved.
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Randomized Controlled Trial Clinical Trial
Adaptive support ventilation for fast tracheal extubation after cardiac surgery: a randomized controlled study.
Adaptive support ventilation (ASV) is a microprocessor-controlled mode of mechanical ventilation that maintains a predefined minute ventilation with an optimal breathing pattern (tidal volume and rate) by automatically adapting inspiratory pressure and ventilator rate to changes in the patient's condition. The aim of the current study was to test the hypothesis that a protocol of respiratory weaning based on ASV could reduce the duration of tracheal intubation after uncomplicated cardiac surgery ("fast-track" surgery). ⋯ A respiratory weaning protocol based on ASV is practicable; it may accelerate tracheal extubation and simplify ventilatory management in fast-track patients after cardiac surgery. The evaluation of potential advantages of the use of such technology on patient outcome and resource utilization deserves further studies.