Anesthesiology
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Obstructive sleep apnea (OSA) is an independent risk factor for difficult and/or impossible mask ventilation during anesthesia induction. Postural change from supine to sitting improves nocturnal breathing in patients with OSA. The purpose of this study was to evaluate the effect of patient position on collapsibility of the pharyngeal airway in anesthetized and paralyzed patients with OSA. The authors tested the hypothesis that the passive pharynx is structurally less collapsible during sitting than during supine posture. ⋯ Postural change from supine to sitting significantly improves collapsibility of pharyngeal airway in anesthetized and paralyzed patients with OSA.
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Sevoflurane may prolong the corrected QT (QTc) interval in healthy humans when administered for induction and maintenance of anesthesia. Little information is available about the dose-response relationship of sevoflurane on the QTc interval. We performed a pharmacodynamic analysis of the relationship between end-tidal sevoflurane concentration (CET) and the QTc. ⋯ Among patients receiving sevoflurane for anesthesia, QTc interval changes correlate to anesthetic level. The Ce50 for significant QTc change is at clinically relevant levels of sevoflurane anesthesia.
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Surgical injury induces production and release of inflammatory mediators in the vicinity of the wound. They in turn trigger nociceptive signaling to produce hyperalgesia and pain. Interleukin-1β plays a crucial role in this process. The mechanism regulating production of this cytokine after incision is, however, unknown. Caspase-1 is a key enzyme that cleaves prointerleukin-1β to its active form. We hypothesized that caspase-1 is a crucial regulator of incisional interleukin-1β levels, nociceptive sensitization, and inflammation. ⋯ The current study demonstrates that the inhibition of caspase-1 reduces postsurgical sensitization and inflammation, likely through a caspase-1/interleukin-1β-dependent mechanism.
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The activity of transient receptor potential vanilloid subtype-1 (TRPV1) receptors, key nociceptive transducers in dorsal root ganglion sensory neurons, is enhanced by protein kinase C epsilon (PKCepsilon) activation. The intravenous anesthetic propofol has been shown to activate PKCepsilon. Our objectives were to examine whether propofol modulates TRPV1 function in dorsal root ganglion neurons via activation of PKCepsilon. ⋯ Our results indicate that propofol modulates TRPV1 sensitivity to capsaicin and that this most likely occurs through a PKCepsilon-mediated phosphorylation of TRPV1.