Critical care : the official journal of the Critical Care Forum
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Low cardiac output states such as left heart failure are characterized by preserved oxygen extraction ratio, which is in contrast to severe sepsis. Near infrared spectroscopy (NIRS) allows noninvasive estimation of skeletal muscle tissue oxygenation (StO2). The aim of the study was to determine the relationship between StO2 and mixed venous oxygen saturation (SvO2) in patients with severe left heart failure with or without additional severe sepsis or septic shock. ⋯ Skeletal muscle StO2 does not estimate SvO2 in patients with severe left heart failure and additional severe sepsis or septic shock. However, in patients with severe left heart failure without additional severe sepsis or septic shock, StO2 values could be used to provide rapid, noninvasive estimation of SvO2; furthermore, the trend in StO2 may be considered a surrogate for the trend in SvO2.
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Comparative Study
Changeovers of vasoactive drug infusion pumps: impact of a quality improvement program.
Hemodynamic instability following the changeover of vasoactive infusion pump (CVIP) is a common problem in the intensive care unit. Several empiric methods are used to achieve CVIP. We hypothesized that the variation in these procedures could generate some morbidity. We sought to assess the effects of the standardization of practice, as a quality improvement program, on the CVIP-induced incidents. ⋯ The present study illustrates that adverse events are common following CVIP, and illustrates the positive impact of a quality improvement program to enhance inpatient safety related to this current process of care.
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Several studies link hematological dysfunction to severity of sepsis. Previously we showed that platelet-derived microparticles from septic patients induce vascular cell apoptosis through the NADPH oxidase-dependent release of superoxide. We sought to further characterize the microparticle-dependent vascular injury pathway. ⋯ We showed that, in sepsis, NO and bacterial elements are responsible for type-specific platelet-derived exosome generation. Those exosomes have an active role in vascular signaling as redox-active particles that can induce endothelial cell caspase-3 activation and apoptosis by generating superoxide, NO and peroxynitrite. Thus, exosomes must be considered for further developments in understanding and treating vascular dysfunction in sepsis.
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The product of growth arrest-specific gene 6 (Gas6) is a vitamin K dependent protein that is secreted by leucocytes and endothelial cells in response to injury and participates in cell survival, proliferation, migration and adhesion. Our purpose was to investigate plasma Gas6 concentration and its relation to organ dysfunction in patients with septic shock. ⋯ Plasma concentrations of Gas6 correlate with disease severity, especially with renal and hepatic dysfunction, in septic shock.
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Comparative Study
Variation in the PaO2/FiO2 ratio with FiO2: mathematical and experimental description, and clinical relevance.
Previous studies have shown through theoretical analyses that the ratio of the partial pressure of oxygen in arterial blood (PaO2) to the inspired oxygen fraction (FiO2) varies with the FiO2 level. The aim of the present study was to evaluate the relevance of this variation both theoretically and experimentally using mathematical model simulations, comparing these ratio simulations with PaO2/FiO2 ratios measured in a range of different patients. ⋯ The PaO2/FiO2 ratio depends on both the FiO2 level and the arterial oxygen saturation level. As a minimum, the FiO2 level at which the PaO2/FiO2 ratio is measured should be defined when quantifying the effects of therapeutic interventions or when specifying diagnostic criteria for acute lung injury and acute respiratory distress syndrome. Alternatively, oxygenation problems could be described using parameters describing shunt and ventilation/perfusion mismatch.