Anesthesiology
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Randomized Controlled Trial Clinical Trial
Epileptiform electroencephalogram during mask induction of anesthesia with sevoflurane.
Sevoflurane is suggested as a suitable anesthetic agent for mask induction in adults. The authors recently found that hyperventilation during sevoflurane-nitrous oxide-oxygen mask induction is associated with cardiovascular hyperdynamic response. We tested the hypothesis that the hyperdynamic response can be explained by electroencephalography (EEG) findings. ⋯ Sevoflurane mask induction elicits epileptiform EEG patterns. These are associated with an increase in heart rate in patients with controlled hyperventilation and also during spontaneous breathing of sevoflurane.
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Randomized Controlled Trial Comparative Study Clinical Trial
Changes in electroencephalogram and autonomic cardiovascular activity during induction of anesthesia with sevoflurane compared with halothane in children.
This study was design to assess clinical agitation, electroencephalogram (EEG) and autonomic cardiovascular activity changes in children during induction of anesthesia with sevoflurane compared with halothane using noninvasive recording of EEG, heart rate, and finger blood pressure. ⋯ Agitation observed during sevoflurane induction was not associated with seizures. Sevoflurane induction induced a marked inhibition of parasympathetic control of heart rate.
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Randomized Controlled Trial Clinical Trial
Effect of dobutamine on splanchnic carbohydrate metabolism and amino acid balance after cardiac surgery.
As a predominant beta-adrenergic agonist, dobutamine may modify blood flow distribution and increase metabolic demands. The authors investigated the effect of a dobutamine-induced increase in cardiac output on splanchnic and femoral blood flow and metabolism in patients after cardiac surgery. ⋯ After coronary artery bypass surgery, dobutamine increased systemic and regional blood flow and decreased systemic and regional oxygen extraction. Dobutamine did not affect splanchnic glucose production or lactate or amino acid balance. This suggests that dobutamine increases splanchnic blood flow without a concomitant increase in hepatosplanchnic metabolism.
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Randomized Controlled Trial Clinical Trial
Beneficial effects from beta-adrenergic blockade in elderly patients undergoing noncardiac surgery.
Perioperative beta-blockade has been shown to improve long-term cardiac outcome in noncardiac surgical patients. A possible mechanism for the reduced risk of perioperative myocardial infarction is the attenuation of the excitotoxic effects of catecholamine surges by beta-blockade. It was hypothesized that beta-blocker-induced alteration of the stress response was responsible for the reported improvements in cardiovascular outcome. Several variables associated with the perioperative use of beta-blockade were also evaluated. ⋯ Beta-blockade does not reduce the neuroendocrine stress response, suggesting that this mechanism is not responsible for the previously reported improved cardiovascular outcome. However, it confers several advantages, including decreased analgesic requirements, faster recovery from anesthesia, and improved hemodynamic stability. The release of cardiac troponin I suggests the occurrence of perioperative myocardial damage in this elderly population, which appears to be independent of the neuroendocrine stress response.
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Randomized Controlled Trial Clinical Trial
Pharyngeal mucosal pressure and perfusion: a fiberoptic evaluation of the posterior pharynx in anesthetized adult patients with a modified cuffed oropharyngeal airway.
Pharyngeal airway devices can exert substantial pressures against the pharyngeal mucosa. The authors assess the relation between pharyngeal mucosal perfusion and directly measured mucosal pressure (MP) in the posterior pharynx using a fiberoptic technique with a modified cuffed oropharyngeal airway (COPA). The authors also measure in vivo intracuff pressure (CP), airway sealing pressure and MP at four locations using an unmodified COPA. ⋯ Pharyngeal mucosal perfusion is reduced progressively in the posterior pharynx when MP is increased from 34 to 80 cm H2O with the COPA. CP provides reliable information about MP and should be less than 120 cm H2O to prevent mucosal ischemia.