Anesthesia and analgesia
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Anesthesia and analgesia · Dec 2011
Comparative StudyEnhancing the relative safety of intentional or unintentional intrathecal methylprednisolone administration by removing polyethylene glycol.
Previous studies have shown that intrathecal methylprednisolone is a very effective treatment for postherpetic neuralgia. However, widespread use of intrathecal methylprednisolone is limited by the presence of polyethylene glycol (PEG) as a preservative in the commercial formulation. In this study, we are proposing a method to reduce the concentration of PEG in the methylprednisolone acetate (MPA) suspension by inverting a vial before sterilely aspirating the contents into a syringe for subsequent injection. The purpose of this brief study was to precisely quantify the concentration of PEG in the MPA suspension. ⋯ We believe that by decreasing the PEG concentration using our method, MPA-related complications will potentially be reduced, and this should be considered in patients with postherpetic neuralgia refractory to other treatments who might be candidates for repeated intrathecal injections.
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Anesthesia and analgesia · Dec 2011
Comparative StudyAn uncalibrated pulse contour method to measure cardiac output during aortic counterpulsation.
Less-invasive monitoring systems, such as pulse contour methods, are increasingly being used to estimate cardiac output (CO). However, alterations in the arterial waveform caused by intraaortic balloon pump counterpulsation may affect the ability of pulse contour algorithms to determine CO. We investigated the reliability of an uncalibrated pulse contour method, the MostCare system, in patients with cardiac failure receiving intraaortic balloon pump counterpulsation by comparing its measurements of CO with those determined by an intermittent thermodilution method. ⋯ The MostCare system provided measurements of CO that were comparable to ThD-CO in patients assisted with an intraaortic balloon pump. The reliability of the MostCare system is not significantly affected by changes in arterial waveform morphology caused by inflation and deflation of the intraaortic balloon pump.
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Anesthesia and analgesia · Dec 2011
Comparative StudyForced-air warming does not worsen air quality in laminar flow operating rooms.
Warm air released by forced-air covers could theoretically disturb laminar airflow in operating rooms. We thus tested the hypothesis that laminar flow performance remains well within rigorous and objective standards during forced-air warming. ⋯ Our results, based on quantitative performance testing methods, indicate that forced-air warming does not reduce operating room air quality during laminar flow ventilation. Because there is no decrement in laminar flow performance, forced-air warming remains an appropriate intraoperative warming method when laminar flow is used.
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Anesthesia and analgesia · Dec 2011
Comparative StudyBupivacaine destabilizes action potential duration in cellular and computational models of long QT syndrome 1.
The effects of the local anesthetic bupivacaine on cardiac action potentials (APs) are mainly attributed to inhibition of cardiac Na(+) channels. The relevance of its ability to also induce high-affinity blockade of human ether-à-gogo-related gene (hERG) channels is unclear. We investigated whether this interaction may functionally become more significant in cellular and computational models of long (L)QT syndromes. ⋯ This study provides evidence that bupivacaine induces inhibition of hERG channels, which is functionally silent under normal conditions but will become more relevant in LQT1-like states in which repolarization relies to a larger degree on hERG channels. Interactions with ion channels other than cardiac Na(+) channels may, therefore, determine the net cardiac effects of bupivacaine when the normal balance of ionic currents is altered.
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Anesthesia and analgesia · Dec 2011
Review Comparative StudyWhen right is right and when it's not: laterality in cardiac structures.