6,655 research outputs found
Should we use early less invasive hemodynamic monitoring in unstable ICU patients?
In the previous issue of Critical Care, Takala and colleagues presented the results of a multicenter study to investigate whether the early presence of less invasive hemodynamic monitoring improves outcome in patients admitted with hemodynamic instability to the intensive care unit. The authors' results suggest that it makes no difference. We discuss these findings and compare them to the literature on early goal-directed therapy in which monitors are used early but with a protocol
Cell-free DNA and outcome in sepsis.
Severe sepsis can be a catastrophic condition that is often associated with poor outcomes. The early diagnosis and management of the condition are vital in order to improve the chances of survival. However, owing to the syndromal nature of its definition and the lack of a biomarker able to accurately confirm the condition, the diagnosis of sepsis is challenging. Even more challenging is the prediction of how these patients will respond to the therapy and whether they will survive the intensive care and the hospital admission
Clustering and coalescence from multiplicative noise: the Kraichnan ensemble
We study the dynamics of the two-point statistics of the Kraichnan ensemble
which describes the transport of a passive pollutant by a stochastic turbulent
flow characterized by scale invariant structure functions. The fundamental
equation of this problem consists in the Fokker-Planck equation for the
two-point correlation function of the density of particles performing spatially
correlated Brownian motions with scale invariant correlations. This problem is
equivalent to the stochastic motion of an effective particle driven by a
generic multiplicative noise. In this paper we propose an alternative and more
intuitive approach to the problem than the original one leading to the same
conclusions. The general features of this new approach make possible to fit it
to other more complex contexts.Comment: IOP-LaTeX, 17 pages J. Phys. A: Theor. Mat. 2008 in pres
What role does the right side of the heart play in circulation?
Right ventricular failure (RVF) is an underestimated problem in intensive care. This review explores the physiology and pathophysiology of right ventricular function and the pulmonary circulation. When RVF is secondary to an acute increase in afterload, the picture is one of acute cor pulmonale, as occurs in the context of acute respiratory distress syndrome, pulmonary embolism and sepsis. RVF can also be caused by right myocardial dysfunction. Pulmonary arterial catheterization and echocardiography are discussed in terms of their roles in diagnosis and treatment. Treatments include options to reduce right ventricular afterload, specific pulmonary vasodilators and inotropes
Transport and fluctuation-dissipation relations in asymptotic and pre-asymptotic diffusion across channels with variable section
We study the asymptotic and pre-asymptotic diffusive properties of Brownian
particles in channels whose section varies periodically in space. The effective
diffusion coefficient is numerically determined by the
asymptotic behavior of the root mean square displacement in different
geometries, considering even cases of steep variations of the channel
boundaries. Moreover, we compared the numerical results to the predictions from
the various corrections proposed in the literature to the well known
Fick-Jacobs approximation. Building an effective one dimensional equation for
the longitudinal diffusion, we obtain an approximation for the effective
diffusion coefficient. Such a result goes beyond a perturbation approach, and
it is in good agreement with the actual values obtained by the numerical
simulations. We discuss also the pre-asymptotic diffusion which is observed up
to a crossover time whose value, in the presence of strong spatial variation of
the channel cross section, can be very large. In addition, we show how the
Einstein's relation between the mean drift induced by a small external field
and the mean square displacement of the unperturbed system is valid in both
asymptotic and pre-asymptotic regimes.Comment: RevTeX 4-1, 11 Pages, 11 pdf figure
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