Anesthesiology
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Alveolar overdistension and repetitive derecruitment-recruitment contribute to ventilator-induced lung injury (VILI). The authors investigated (1) whether inflammatory cell activation due to VILI was assessable by positron emission tomography and (2) whether cell activation due to dynamic overdistension alone was detectable when other manifestations of VILI were not yet evident. ⋯ The authors could detect regional neutrophil activation in VILI even when end-expiratory derecruitment was prevented and impairment of gas exchange was not evident. Concomitant end-expiratory derecruitment converted this activation into profound inflammation with decreased aeration and regional shunting.
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The physicochemical properties of propofol could allow diffusion across the alveolocapillary membrane and a measurable degree of pulmonary propofol elimination. The authors tested this hypothesis and showed that propofol can be quantified in expiratory air and that propofol breath concentrations reflect blood concentrations. This could allow real-time monitoring of relative changes in the propofol concentration in arterial blood during total intravenous anesthesia. ⋯ Ion-molecule reaction mass spectrometry may allow the continuous and noninvasive monitoring of expiratory propofol levels in patients undergoing general anesthesia.
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Propofol (2,6-diisopropylphenol) has some volatility, so it can be detected in expired breath of individuals receiving intravenous propofol. This study measured volatile propofol exhaled by patients and investigated the relation between exhaled and plasma propofol concentrations. ⋯ Agreement between plasma and exhaled propofol concentrations suggests that proton transfer mass spectrometry can be used for real-time propofol monitoring.
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The safety of performing magnetic resonance imaging (MRI) in patients with spinal cord stimulation (SCS) systems needs to be documented. A prospective in vivo study in patients with SCS, exploring the changes produced by MRI and the associated side effects, was performed. ⋯ Under the conditions of the described protocol, MRI in patients with SCS systems resulted in few complications. None of the recorded problems were serious, and in no case were patients harmed or the systems reprogrammed. Maximum patient satisfaction was reported in all cases.
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Cannabinoids bind to cannabinoid receptors type 1 and 2 and produce analgesia in several pain models, but central side effects from cannabinoid 1 receptors limit their clinical use. Cannabinoid 2 receptors reduce inflammatory responses in the periphery by acting on immune cells, and they are present on glia in the central nervous system. This study tested whether spinal cannabinoid activation would induce analgesia, glial inhibition, and central side effects in a postoperative model or incisional pain. ⋯ These data indicate that intrathecal administration of cannabinoid receptor agonists may provide postoperative analgesia while reducing spinal glial activation, and that selective cannabinoid 2 receptor agonists may do so without central side effects.