Anesthesiology
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Clinical Trial
Use of dynamic negative airway pressure (DNAP) to assess sedative-induced upper airway obstruction.
Traditional methods of assessing ventilatory effects of sedative agents do not measure their propensity to cause upper airway obstruction (UAO). The primary objective of this study was to develop a method, using dynamic negative airway pressure (DNAP), for replicating UAO during deep sedation. ⋯ Dynamic Negative Airway Pressure is a useful method for provoking midazolam-induced UAO, and may potentially be used to compare the potential for different sedatives and patient factors to cause UAO. Flumazenil was completely effective in reversing the potential for midazolam to cause UAO.
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Clinical Trial
Can assessment for obstructive sleep apnea help predict postadenotonsillectomy respiratory complications?
The aim of this study was to determine the frequency and type of respiratory complications after adenotonsillectomy in children. A second aim was to assess the ability of preoperative sleep studies to identify children at risk for respiratory complications. ⋯ The data suggest, but do not prove, that preoperative nocturnal oximetry could be a useful preoperative test to identify children who are at increased risk for postoperative respiratory complications.
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The authors recently established that the analgesic actions of the inhalation anesthetic nitrous oxide were mediated by noradrenergic bulbospinal neurons and spinal alpha2B adrenoceptors. They now determined whether noradrenergic brainstem nuclei and descending spinal pathways are responsible for the antinociceptive actions of the inhalation anesthetic isoflurane, and which alpha adrenoceptors mediate this effect. ⋯ The authors suggest that, at clinically effective concentrations, isoflurane can modulate nociception via three different mechanisms: (1) a pronociceptive effect requiring descending spinal pathways, brainstem noradrenergic nuclei, and supraspinal alpha1 adrenoceptors; (2) an antinociceptive effect requiring descending noradrenergic neurons and spinal alpha2A adrenoceptors; and (3) an antinociceptive effect mediated within the spinal cord for which no role for adrenergic mechanism has been found.
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Randomized Controlled Trial Multicenter Study Comparative Study Clinical Trial
Cognitive impairment after small-dose ketamine isomers in comparison to equianalgesic racemic ketamine in human volunteers.
Ketamine is increasingly used in pain therapy but may impair brain functions. Mood and cognitive capacities were compared after equianalgesic small-dose S(+)-, R(-)-, and racemic ketamine in healthy volunteers. ⋯ Early after injection, ketamine isomers induce less tiredness and cognitive impairment than equianalgesic small-dose racemic ketamine. In addition, S(+)-ketamine causes less decline in concentration capacity and primary memory. The differences in drug effects cannot be explained by stereoselective action on one given receptor.