Anesthesiology
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Anesthesia care for the patients undergoing ophthalmologic surgical procedures during local/regional anesthesia balances goals of patient comfort with safety and an optimal outcome in a highly cost-conscious environment. This article discusses current practices and trends in anesthesia care with respect to sedation for eye surgery during local/regional anesthesia. Although there is no evidence that one local/regional anesthesia technique or sedation analgesia regimen is superior to the others, this review highlights important differences between these varied approaches. ⋯ Changes in surgical techniques have increased the popularity of topical anesthesia, which reduces the need for sedation analgesia and may lessen the need for an anesthesia practitioner. The involvement of an anesthesia practitioner in eye surgery varies from facility to facility based on costs, anesthesiologist availability, and local standards. Anesthesia care choices are often made based on surgeon skill and anesthesiologist comfort, as well as the expectations and needs of the patient.
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Clinical Trial
Differential contribution of sodium channel subtypes to action potential generation in unmyelinated human C-type nerve fibers.
Multiple voltage-dependent sodium channels (Na(v)) contribute to action potentials and excitability of primary nociceptive neurons. The aim of the current study was to characterize subtypes of Na(v) that contribute to action potential generation in peripheral unmyelinated human C-type nerve fibers. ⋯ These data indicate that more than one type of Na(v) contributes to the generation of action potentials in unmyelinated human C-type nerve fibers. The peak height of an action potential produced by a short electrical impulse is dependent on the activation of tetrodotoxin-resistant ion channels. In contrast, membrane threshold and action potential peak height at the end of a slow membrane depolarization are regulated by a subtype of Na(v) with high sensitivity to low concentrations of tetrodotoxin, lidocaine, and mexiletine. The electrophysiologic and pharmacologic characteristics may indicate the functional activity of the Na(v) 1.7 subtype of voltage-dependent sodium channels.
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Mechanical ventilation (MV) may activate the innate immune system, causing the release of cytokines. The resulting proinflammatory state is a risk factor for ventilator-induced lung injury. Cytokine increase results from direct cellular injury but may also result from cyclic stretch alone as demonstrated in vitro: mechanotransduction. To study mechanotransduction in vivo, the authors used an animal MV model with clinically relevant ventilator settings, avoiding alveolar damage. ⋯ Mechanical ventilation induces reversible cytokine increase and leukocyte influx with preserved tissue integrity. This model offers opportunities to study the pathophysiologic mechanisms behind ventilator-induced lung injury and the contribution of MV to the "multiple-hit" concept.
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Whether patients who subsequently develop early postoperative delirium have a genetic predisposition that renders them at risk for postoperative delirium has not been determined. ⋯ Apolipoprotein e4 carrier status was associated with an increased risk for early postoperative delirium after controlling for known demographic and clinical risk factors. These results suggest that genetic predisposition plays a role and may interact with anesthetic/surgical factors contributing to the development of early postoperative delirium.
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Chronic pain models are commonly defined as either nerve-injury or inflammation models, but recent work suggests inflammatory processes are important in nerve injury-induced pain. ⋯ Several components of the spinal nerve injury model are responsive to corticosteroid, suggesting inflammatory processes are important in the development of neuropathic pain. The observation that TA was effective when given starting at the time of injury suggests that steroid treatment might alter the development of chronic pain after surgical procedures that involve nerve injury, such as amputation or hernia repair.