Anesthesia and analgesia
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Anesthesia and analgesia · Feb 2010
The direct effect of levobupivacaine in isolated rat aorta involves lipoxygenase pathway activation and endothelial nitric oxide release.
Levobupivacaine is a long-acting local anesthetic with a clinical profile similar to that of racemic bupivacaine but with a greater margin of safety. Levobupivacaine produces dose-dependent vasoconstriction in vivo. Our goal in this in vitro study was to investigate the role of pathways involved in arachidonic acid metabolism in the levobupivacaine-induced contraction of isolated rat aorta and to determine which endothelium-derived vasodilators are involved in the modulation of levobupivacaine-induced contraction. ⋯ Our data indicate that levobupivacaine-induced contraction of rat aortic smooth muscle is mediated mainly by activation of the lipoxygenase pathway and in part by activation of the cyclooxygenase pathway. In addition, activation of the lipoxygenase pathway seems to facilitate calcium influx via L-type calcium channels. Endothelial nitric oxide attenuates levobupivacaine-induced contraction.
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Anesthesia and analgesia · Feb 2010
The impact of cardiopulmonary bypass on systemic interleukin-6 release, cerebral nuclear factor-kappa B expression, and neurocognitive outcome in rats.
Neurocognitive deficits after cardiac surgery with cardiopulmonary bypass (CPB) continue to affect patients' quality of life, and an inflammatory reaction may be one of the contributors. We designed this experiment to study perioperative systemic interleukin-6 (IL-6) concentrations, cerebral expression of nuclear factor-kappa B (NF-kappaB), and neurocognitive outcome after CPB in young rats. The impact of oxygenator size on these outcomes was also assessed. ⋯ Pronounced systemic inflammatory responses to experimental CPB associated with increased hippocampal expression of NF-kappaB were not accompanied by neurocognitive impairment. This suggests that other factors beyond CPB and inflammatory responses might contribute to adverse neurocognitive outcomes after cardiac surgery.
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Anesthesia and analgesia · Feb 2010
The effects of vasoactive drugs on intestinal functional capillary density in endotoxemic rats: intravital video-microscopy analysis.
The use of vasoactive drugs to restore arterial blood pressure in patients with septic shock remains a cornerstone of intensive care medicine. However, vasopressors can accentuate the hypoperfusion of the gut during septic shock, allowing bacterial translocation and endotoxemia. In this study, we compared the effects of different vasoactive drugs on intestinal microcirculation and tissue oxygenation, independent of the effects of fluid therapy, in a rat model of endotoxemic shock. ⋯ This study confirms dissociation of the systemic hemodynamic and microvascular alterations in an experimental model of septic shock. Moreover, the results indicate that the use of dopamine, dobutamine, and dobutamine in combination with norepinephrine yields a protective effect on the microcirculation of the intestinal muscular layer in endotoxemic rats.