Anesthesiology
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Randomized Controlled Trial Comparative Study
Dreaming and electroencephalographic changes during anesthesia maintained with propofol or desflurane.
Dream recall is reportedly more common after propofol than after volatile anesthesia, but this may be due to delayed emergence or more amnesia after longer-acting volatiles. The electroencephalographic signs of dreaming during anesthesia and the differences between propofol and desflurane also are unknown. The authors therefore compared dream recall after propofol- or desflurane-maintained anesthesia and analyzed electroencephalographic patterns in dreamers and nondreamers and in propofol and desflurane patients for similarities to rapid eye movement and non-rapid eye movement sleep. ⋯ Anesthetic-related dreaming seems to occur just before awakening and is associated with a rapid eye movement-like electroencephalographic pattern.
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Randomized Controlled Trial
Placental transfer and fetal metabolic effects of phenylephrine and ephedrine during spinal anesthesia for cesarean delivery.
Use of ephedrine in obstetric patients is associated with depression of fetal acid-base status. The authors hypothesized that the mechanism underlying this is transfer of ephedrine across the placenta and stimulation of metabolism in the fetus. ⋯ Ephedrine crosses the placenta to a greater extent and undergoes less early metabolism and/or redistribution in the fetus compared with phenylephrine. The associated increased fetal concentrations of lactate, glucose, and catecholamines support the hypothesis that depression of fetal pH and base excess with ephedrine is related to metabolic effects secondary to stimulation of fetal beta-adrenergic receptors. Despite historical evidence suggesting uteroplacental blood flow may be better maintained with ephedrine, the overall effect of the vasopressors on fetal oxygen supply and demand balance may favor phenylephrine.
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Randomized Controlled Trial Comparative Study
Preserved memory function during bispectral index-guided anesthesia with sevoflurane for major orthopedic surgery.
Memory function under anesthesia is undesired but may arise from light hypnosis as well as stress-enhanced learning during surgery. The bispectral index (BIS, Aspect Medical Systems, Norwood, MA) is a monitor of hypnotic state that can help to avoid light hypnosis (i.e., BIS above 60). This study tested the hypothesis that BIS-guided anesthesia maintaining BIS 50-60 reduces the likelihood of memory function under anesthesia. ⋯ BIS titration to BIS 50-60 does not necessarily curb memory function under anesthesia when BIS values higher than 60 occur. Preoperative analgesia attenuated the likelihood of memory function under anesthesia.
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Randomized Controlled Trial Comparative Study
Analgesic efficacy of peripheral kappa-opioid receptor agonist CR665 compared to oxycodone in a multi-modal, multi-tissue experimental human pain model: selective effect on visceral pain.
Peripherally selective opioids may be beneficial in visceral pain management due to absence of centrally mediated side effects. The objectives of this study were: (1) to assess the effects of a peripherally selective tetrapeptide kappa-opioid receptor agonist, CR665, on experimental pain from multi-modal stimulation of skin, muscle, and viscera, and (2) contrast these effects with those of oxycodone (centrally acting opioid). ⋯ CR665 had a selective effect on visceral pain. Oxycodone exhibited a generalized effect, elevating thresholds for cutaneous, deep somatic, and visceral pain stimulation.