Anesthesia and analgesia
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Anesthesia and analgesia · Apr 2016
Observational StudyAn Ethnographic Observational Study to Evaluate and Optimize the Use of Respiratory Acoustic Monitoring in Children Receiving Postoperative Opioid Infusions.
Respiratory depression in children receiving postoperative opioid infusions is a significant risk because of the interindividual variability in analgesic requirement. Detection of respiratory depression (or apnea) in these children may be improved with the introduction of automated acoustic respiratory rate (RR) monitoring. However, early detection of adverse events must be balanced with the risk of alarm fatigue. Our objective was to evaluate the use of acoustic RR monitoring in children receiving opioid infusions on a postsurgical ward and identify the causes of false alarm and optimal alarm thresholds. ⋯ In this study, the use of RR monitoring did not improve the detection of respiratory depression. An RR threshold, which would have been predictive of desaturations, would have resulted in an unacceptably high false alarm rate. Future research using a combination of variables (e.g., SpO2 and RR), or the measurement of tidal volumes, may be needed to improve patient safety in the postoperative ward.
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It has been increasingly suggested that propofol protects against hypoxic-/ischemic-induced neuronal injury. As evidenced by hemorrhage-induced stroke, hemorrhage into the brain may also cause brain damage. Whether propofol protects against hemorrhage-induced brain damage remains unknown. Therefore, in this study, we investigated the effects of propofol on hemoglobin-induced cytotoxicity in cultured mouse cortical neurons. ⋯ These results from our current proof-of-concept study should promote more research in vitro and in vivo to develop better anesthesia care for patients with hemorrhagic stroke.
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Anesthesia and analgesia · Apr 2016
Clinical Concentrations of Local Anesthetics Bupivacaine and Lidocaine Differentially Inhibit Human Kir2.x Inward Rectifier K+ Channels.
Inward rectifier K channels of the Kir2.x subfamily are widely expressed in neuronal tissues, controlling neuronal excitability. Previous studies reported that local anesthetics (LAs) do not affect Kir2 channels. However, the effects have not been studied at large concentrations used in regional anesthesia. ⋯ The results indicate that both LAs at clinical concentrations equilibrated rapidly with the intracellular milieu, differentially inhibiting Kir2.x channel function from the cytoplasmic side.
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Anesthesia and analgesia · Apr 2016
Lung Perfusion and Ventilation During Cardiopulmonary Bypass Reduces Early Structural Damage to Pulmonary Parenchyma.
It is unclear whether maintaining pulmonary perfusion and ventilation during cardiopulmonary bypass (CPB) reduces pulmonary inflammatory tissue injury compared with standard CPB where the lungs are not ventilated and are minimally perfused. In this study, we tested the hypothesis that maintenance of lung perfusion and ventilation during CPB decreases regional lung inflammation, which may result in less pulmonary structural damage. ⋯ Maintenance of lung perfusion and ventilation during CPB attenuated early histologic signs of pulmonary inflammation and injury compared with standard CPB. Although increased compared with control animals, there were no differences in serum or BAL IL in animals receiving lung ventilation and perfusion during CPB compared with standard CPB.
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Anesthesia and analgesia · Apr 2016
Blood Products, Crystalloids, and Rapid Infusion: An Experimental Study.
Electromagnetic coil overheating, deformation, occlusion, and rupture during rapid infuser use have been previously reported. Although the etiology is unclear, prolonged machine use and reconstitution of citrated blood components with crystalloid solutions in the reservoir have been implicated. Lactated Ringer's (LR) solution is of particular concern as a diluent because of its calcium content. We sought to reproduce this failure mode using different infusion rates and different combinations of fluids for blood product reconstitution in the reservoir. We also introduced calcium chloride (CaCl2) to the mix to determine its role in macroscopic clot formation. ⋯ In this in vitro study, we were unable to reproduce the failure mode characterized by coil overheating, deformation, and rupture previously reported with use of the FMS 2000. Addition of CaCl2 in the range of 200 mg caused macroscopic coagulation in the reservoir when added to crystalloids or albumin mixed with different combinations of blood products containing FTP.