Anesthesiology
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Intraoperative hypotension may contribute to postoperative acute kidney injury (AKI) and myocardial injury, but what blood pressures are unsafe is unclear. The authors evaluated the association between the intraoperative mean arterial pressure (MAP) and the risk of AKI and myocardial injury. ⋯ Even short durations of an intraoperative MAP less than 55 mmHg are associated with AKI and myocardial injury. Randomized trials are required to determine whether outcomes improve with interventions that maintain an intraoperative MAP of at least 55 mmHg.
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Parturients with intracranial lesions are often assumed to have increased intracranial pressure, even in the absence of clinical and radiographic signs. The risk of herniation after an inadvertent dural puncture is frequently cited as a contraindication to neuraxial anesthesia. This article reviews the relevant literature on the use of neuraxial anesthesia in parturients with known intracranial pathology, and proposes a framework and recommendations for assessing risk of neurologic deterioration, with epidural analgesia or anesthesia, or planned or inadvertent dural puncture. The authors illustrate these concepts with numerous case examples and provide guidance for the practicing anesthesiologist in determining the safety of neuraxial anesthesia.
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Oxidative stress is implicated in pathogenesis of cardiac reperfusion injury, characterized by cellular Ca overload and hypercontracture. Volatile anesthetics protect the heart against reperfusion injury primarily by attenuating Ca overload. This study investigated electrophysiological mechanisms underlying cardioprotective effects of sevoflurane against oxidative stress-induced cellular injury. ⋯ Sevoflurane protected ventricular myocytes against H2O2-induced Ca overload and hypercontracture, presumably by affecting multiple Ca transport pathways, including ICa,L, Na/Ca exchanger and ryanodine receptor. These actions appear to mediate cardioprotection against reperfusion injury associated with oxidative stress.