Anesthesiology
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Randomized Controlled Trial
Offset analgesia in neuropathic pain patients and effect of treatment with morphine and ketamine.
Offset analgesia, in which a disproportionally large amount of analgesia becomes apparent upon a slight decrease in noxious heat stimulation, has not been described previously in patients with chronic pain. ⋯ These data indicate that offset analgesia is fully developed at the age of 6 yr and does not undergo additional maturation. The reduced or absent responses observed in patients with chronic neuropathic pain indicate the inability to modulate changes in pain stimulation, with perseverance of pain perception in situations in which healthy subjects display signs of strong analgesia. Both central and peripheral sites may be involved in the altered offset analgesia responses in these patients.
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Randomized Controlled Trial
Intraoperative acceleromyography monitoring reduces symptoms of muscle weakness and improves quality of recovery in the early postoperative period.
The subjective experience of residual neuromuscular blockade after emergence from anesthesia has not been examined systematically during postanesthesia care unit (PACU) stays. The authors hypothesized that acceleromyography monitoring would diminish unpleasant symptoms of residual paresis during recovery from anesthesia by reducing the percentage of patients with train-of-four ratios less than 0.9. ⋯ Acceleromyography monitoring reduces the incidence of residual blockade and associated unpleasant symptoms of muscle weakness in the PACU and improves the overall quality of recovery.
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The role of continuous central venous oxygen saturation (ScvO₂) oximetry during pediatric cardiac surgery for predicting adverse outcomes is not known. Using a recently available continuous ScvO₂ oximetry catheter, we examined the association between venous oxygen desaturations and patient outcomes. We hypothesized that central venous oxygen desaturations are associated with adverse clinical outcomes. ⋯ We demonstrate that ScvO₂ desaturations by continuous oximetry are associated with major adverse events in pediatric patients undergoing cardiac surgery. The most significant associations with major adverse events are seen in patients with greater than 18 min of central venous saturations less than 40%. Our results support the further investigation of ScvO₂ as a potential target parameter in high-risk pediatric patients to minimize the risk of major adverse events.
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Ultrasound energy exerts important cellular, genetic, thermal, and mechanical effects. Concern about the safety of ultrasound prompted several agencies to devise regulatory limits on the machine output intensities. ⋯ To date, ultrasound imaging appears to be safe for use in regional anesthesia and pain medicine interventions, and adherence to limiting the output of ultrasound machines as outlined by the Food and Drug Administration may avoid complications in the future. This article reviews ultrasound-related biologic effects, the role of the regulatory agencies in ensuring safety with the use of ultrasound, and the limitations and implications of ultrasound use in humans.
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Local anesthetics (LAs) are typically used for regional anesthesia but can be given systemically to mitigate postoperative pain, supplement general anesthesia, or prevent cardiac arrhythmias. However, systemic application or inadvertent intravenous injection can be associated with substantial toxicity, including seizure induction. The molecular basis for this toxic action remains unclear. ⋯ These data suggest that increased neuronal excitability associated with TASK channel inhibition by LAs contributes to seizure induction. Because all LAs were capable of evoking seizures in TASK channel deleted mice, albeit at higher doses, the results imply that other molecular targets must also be involved in this toxic action.