Anesthesiology
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Inhibition of KCNQ2/Q3 channels may cause convulsion in humans. The interaction of bupivacaine with these channels is unknown. The anticonvulsant retigabine activates KCNQ2/Q3 channels and may reverse inhibitory actions of bupivacaine. Potassium channel stimulation may thus constitute a novel approach to treat local anesthetic-induced seizures. The aim of this study was to characterize bupivacaine effects on KCNQ2/Q3 channels and to investigate whether retigabine reverses the effects of the local anesthetic. ⋯ The anticonvulsant retigabine at nanomolar concentrations reverses the inhibitory effect of micromolar concentrations of bupivacaine. Our results allow the hypothesis that activation of KCNQ2/Q3 channels by retigabine may offer a novel therapeutic approach for the treatment of bupivacaine-induced seizures.
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Doses of volatile anesthetics around 0.3 minimum alveolar concentration (MAC) inhibit learning. However, threshold amnesic doses and relative potencies between agents are not well established. The authors determined amnesic potency in rats for four common volatiles and nitrous oxide. ⋯ Amnesic potency differs between agents; nitrous oxide is most potent and halothane is least potent relative to MAC. The amnesic threshold ranges from 0.06 to 0.3 MAC. The correlation between potency and oil:gas partition coefficients suggests a fundamental role for hydrophobicity in mediating amnesia, similar to its association with MAC. Some agents (e.g., halothane) may enhance aversive memory retention at doses typically encountered during emergence.
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Randomized Controlled Trial Clinical Trial
Effect of clonidine on cardiovascular morbidity and mortality after noncardiac surgery.
Perioperative myocardial ischemia occurs in 20-40% of patients at risk for cardiac morbidity and is associated with a ninefold increase in risk of cardiac morbidity. ⋯ Perioperative administration of clonidine for 4 days to patients at risk for coronary artery disease significantly reduces the incidence of perioperative myocardial ischemia and postoperative death.
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Randomized Controlled Trial Clinical Trial
Hemofiltration but not steroids results in earlier tracheal extubation following cardiopulmonary bypass: a prospective, randomized double-blind trial.
Activation of the inflammatory cascade is thought to account for some of the respiratory dysfunction and prolonged mechanical ventilation associated with cardiopulmonary bypass. The objective of this investigation was to identify whether perioperative steroids or hemofiltration during cardiopulmonary bypass, by their attenuation of inflammation, would reduce duration of mechanical ventilation after cardiac surgery. ⋯ Hemofiltration and steroids are both previously reported to attenuate the inflammatory response but only hemofiltration reduced time to tracheal extubation for adults after cardiopulmonary bypass in this study.
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Randomized Controlled Trial Clinical Trial
A comparison of sex- and weight-based ProSeal laryngeal mask size selection criteria: a randomized study of healthy anesthetized, paralyzed adult patients.
The authors compared the manufacturer's weight-based formula (size 3 for weight < 50 kg, size 4 for weight 50-70 kg, and size 5 for weight > 70 kg) with a sex-based formula (size 4 for women and size 5 for men) for selecting the appropriate size of ProSeal laryngeal mask airway. ⋯ Size selection for the ProSeal laryngeal mask airway is equally effective using the manufacturer's weight-based formula or the sex-based formula in healthy, anesthetized, paralyzed adult patients, but leakage of small volumes of air from the mouth occurs less frequently with the sex-based formula.