Journal of anesthesia
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Journal of anesthesia · Aug 2013
Activation of ATP-sensitive potassium channels by nicorandil is preserved in aged vascular smooth muscle cells in rats.
Nicorandil, an ATP-sensitive potassium (KATP) channel opener having the properties of a nitrate, causes vasodilation, particularly of coronary arteries, and has been reported to reduce the frequency of perioperative cardiac events. We previously demonstrated that isoflurane could activate vascular KATP channels through an intracellular signaling pathway, but that this isoflurane-induced channel opening is suppressed by aging. Here, we investigated whether advanced age modifies nicorandil-induced activation of vascular KATP channels. ⋯ Bath application of nicorandil (0.1-100 μM) activated KATP channels to a level similar to that observed in VSMCs from the arteries of both adult and aged rats. Furthermore, concomitant bath application of nicorandil in the aged group dose-dependently ameliorated the age-related reduction in isoflurane-induced vascular KATP channel activation. Our findings indicate that nicorandil could be used effectively in elderly patients to directly activate vascular KATP channels during the perioperative period.
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Journal of anesthesia · Aug 2013
Smoking as a risk factor for intraoperative hypoxemia during one lung ventilation.
Smoking is associated with many intra and postoperative events, especially respiratory complications. Hypoxemia and airway damage are found to aggravate any pre-existing respiratory pathology among smokers. One lung ventilation (OLV) carries a 4-10 % risk of development of hypoxia. ⋯ From this study it can be concluded that for heavy smoker patients there was a significant reduction in arterial oxygen tension (PaO(2)) in comparison with non-smokers. However, hypoxemia reported for both groups was comparable.
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Journal of anesthesia · Aug 2013
ReviewQT interval abnormalities: risk factors and perioperative management in long QT syndromes and Torsades de Pointes.
Electrophysiological abnormalities of the QT interval of the standard electrocardiogram are not uncommon. Congenital long QT syndrome is due to mutations of several possible genes (genotype) that result in prolongation of the corrected QT interval (phenotype). Abnormalities of the QT interval can be acquired and are often drug-induced. ⋯ If not recognized and corrected quickly, QT interval abnormalities may precipitate potentially fatal ventricular dysrhythmias. The main mechanism responsible for the development of QT prolongation is blockade of the rapid component of the delayed rectifier potassium current (I kr), encoded for by the human-ether-a-go-go-related gene (hERG). The objectives of this review were (1) to describe the electrical pathophysiology of QT interval abnormalities, (2) to differentiate congenital from acquired QT interval abnormalities, (3) to describe the currently known risk factors for QT interval abnormalities, (4) to identify current drug-induced causes of acquired QT interval abnormalities, and (5) to recommend immediate and effective management strategies to prevent unanticipated dysrhythmias and deaths from QT abnormalities in the perioperative period.
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Journal of anesthesia · Aug 2013
Quantitative measurement of blood remifentanil concentration: development of a new method and clinical application.
We have developed a new detection method of blood remifentanil concentration using a gas chromatography-mass spectrometry(GC-MS) with fentanyl as the internal standard(IS). The detection was performed at m/z 168 and 245 for remifentanil and fentanyl, respectively. In addition, the retention times of remifentanil and fentanyl were 5 min 45 s and 6 min 51 s, respectively. ⋯ Measured blood remifentanil concentration was 3.59 ± 0.74 ng/ml at the end of remifentanil infusion, and the ime for a decrease in blood remifentanil concentration by half was ~2 min. Remifentanil concentration was below the detection limit 30 min after the cessation. Thus, we have confirmed that this new method is clinically applicable.