Anesthesiology
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Volatile anesthetics show an ischemic preconditioning-like cardioprotective effect, whereas intravenous anesthetics have cardioprotective effects for ischemic-reperfusion injury. Although recent evidence suggests that mitochondrial adenosine triphosphate-regulated potassium (mitoK(ATP)) channels are important in cardiac preconditioning, the effect of anesthetics on mitoK(ATP) is unexplored. Therefore, the authors tested the hypothesis that anesthetics act on the mitoK(ATP) channel and mitochondrial flavoprotein oxidation. ⋯ Inhalational anesthetics induce flavoprotein oxidation through opening of the mitoK(ATP) channel. This may be an important mechanism contributing to anesthetic-induced preconditioning. Cardioprotective effects of intravenous anesthetics may not be dependent on flavoprotein oxidation, but the administration of propofol or pentobarbital may potentially inhibit the cardioprotective effect of inhalational anesthetics.
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Clinical Trial
Internal jugular vein occlusion test for rapid diagnosis of misplaced subclavian vein catheter into the internal jugular vein.
During subclavian vein catheterization, the most common misplacement of the catheter is cephalad, into the ipsilateral internal jugular vein (IJV). This can be detected by chest radiography. However, after any repositioning of the catheter, subsequent chest radiography is required. In an effort to simplify the detection of a misplaced subclavian vein catheter, the authors assessed a previously published detection method. ⋯ The IJV occlusion test successfully detects the misplacement of subclavian vein catheter into the IJV. However, it does not detect any other misplacement. The test may allow avoidance of repeated exposure to x-rays after catheter insertion and repositioning.
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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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Clinical Trial
The transfer half-life of morphine-6-glucuronide from plasma to effect site assessed by pupil size measurement in healthy volunteers.
Clinical and experimental data suggested a long delay between the plasma concentration versus time course of morphine-6-glucuronide and the time course of its central opioid effects. This study was aimed at the quantification of the transfer half-life (t(1/2,ke0)) of this delay. ⋯ The reported numerical value of the t(1/2,ke0) of M6G in humans obtained after direct administration of M6G is a step toward a complete modeling approach to the prediction of the clinical effects of morphine. The study raises questions about the high interindividual variability of the transfer half-life between plasma and effect site (ke0) values and the apparent low potency of M6G.