Anesthesiology
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Historical Article
Etymology of Letheon: Nineteenth-century Linguistic Effervescence.
In late 1846, following his successful public demonstrations of surgical anesthesia, Boston dentist William T. G. Morton selected Letheon as the commercial name for the ether-based "preparation" he had used to produce insensibility to pain. ⋯ By one unverified account, the name Letheon might have been coined independently by both Augustus Addison Gould, M. D., and Henry Jacob Bigelow, M. D.
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Randomized Controlled Trial
Analgesic and Respiratory Depressant Effects of R-dihydroetorphine: A Pharmacokinetic-Pharmacodynamic Analysis in Healthy Male Volunteers.
There is an ongoing need for potent opioids with less adverse effects than commonly used opioids. R-dihydroetorphine is a full opioid receptor agonist with relatively high affinity at the μ-, δ- and κ-opioid receptors and low affinity at the nociception/orphanin FQ receptor. The authors quantified its antinociceptive and respiratory effects in healthy volunteers. The authors hypothesized that given its receptor profile, R-dihydroetorphine will exhibit an apparent plateau in respiratory depression, but not in antinociception. ⋯ Over the dose range studied, R-dihydroetorphine exhibited a plateau in respiratory depression, but not in analgesia. Whether these experimental advantages extrapolate to the clinical setting and whether analgesia has no plateau at higher concentrations than investigated requires further studies.
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Functional brain connectivity studies can provide important information about changes in brain-state dynamics during general anesthesia. In adults, γ-aminobutyric acid-mediated agents disrupt integration of information from local to the whole-brain scale. Beginning around 3 to 4 months postnatal age, γ-aminobutyric acid-mediated anesthetics such as sevoflurane generate α-electroencephalography oscillations. In previous studies of sevoflurane-anesthetized infants 0 to 3.9 months of age, α-oscillations were absent, and power spectra did not distinguish between anesthetized and emergence from anesthesia conditions. Few studies detailing functional connectivity during general anesthesia in infants exist. This study's aim was to identify changes in functional connectivity of the infant brain during anesthesia. ⋯ Sevoflurane is associated with decreased capacity for efficient information transfer in the infant brain. Such findings strengthen the hypothesis that conscious processing relies on an efficient system of integrated information transfer across the whole brain.