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Search Results: 1 - 10 of 1847 matches for " Bertrand Souweine "
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Mortality associated with timing of admission to and discharge from ICU: a retrospective cohort study
Kevin B Laupland, Benoit Misset, Bertrand Souweine, Alexis Tabah, Elie Azoulay, Dany Goldgran-Toledano, Anne-Sylvie Dumenil, Aurélien Vésin, Samir Jamali, Hatem Kallel, Christophe Clec'h, Michael Darmon, Carole Schwebel, Jean-Francois Timsit
BMC Health Services Research , 2011, DOI: 10.1186/1472-6963-11-321
Abstract: Adults (≥18 years) admitted to French ICUs participating in Outcomerea between January 2006 and November 2010 were included.Among the 7,380 patients included, 61% (4,481) were male, the median age was 62 (IQR, 49-75) years, and the median SAPS II score was 40 (IQR, 28-56). Admissions to ICU occurred during weekends (Saturday and Sunday) in 1,708 (23%) cases, during the night (18:00-07:59) in 3,855 (52%), and on nights and/or weekends in 4,659 (63%) cases. Among 5,992 survivors to ICU discharge, 903 (15%) were discharged on weekends, 659 (11%) at night, and 1,434 (24%) on nights and/or weekends. After controlling for a number of co-variates using logistic regression analysis, admission during the after hours was not associated with an increased risk for death. However, patients discharged from ICU on nights were at higher adjusted risk (odds ratio, 1.54; 95% confidence interval, 1.12-2.11) for death.In this study, ICU discharge at night but not admission was associated with a significant increased risk for death. Further studies are needed to examine whether minimizing night time discharges from ICU may improve outcome.Patients who suffer acute illness and are admitted during the "after hours" (weekends or nights) may be at higher risk for adverse outcome as compared to patients admitted during weekdays [1]. Cavallazzi et al recently conducted a meta-analysis of ten studies conducted in adult ICUs and found that while night time admission was not associated with an increased risk, a small but significant increased risk for death was associated with weekend admission [2]. Since, Kuijsten et al reported a relative risk for death associated with admission in the afterhours of 1.059 (95% confidence interval 1.031-1.088) among 149,894 admissions to Dutch ICUs [3]. More recently Kevat et al reported on 245,057 admissions to Australian ICUs and found an increased risk for hospital mortality associated with admission during evenings/nights (17% vs. 14%; p < 0.001) and during
Prognostic consequences of borderline dysnatremia: pay attention to minimal serum sodium change
Michael Darmon, Eric Diconne, Bertrand Souweine, Stéphane Ruckly, Christophe Adrie, Elie Azoulay, Christophe Clec'h, Ma?té Garrouste-Orgeas, Carole Schwebel, Dany Goldgran-Toledano, Hatem Khallel, Anne-Sylvie Dumenil, Samir Jamali, Christine Cheval, Bernard Allaouchiche, Fabrice Zeni, Jean-Fran?ois Timsit
Critical Care , 2013, DOI: 10.1186/cc11937
Abstract: Observational study on a prospective database fed by 13 intensive care units (ICUs). Unselected patients with ICU stay longer than 48 h were enrolled over a 14-year period were included in this study. Mild to severe hyponatremia were defined as serum sodium concentration < 135, < 130, and < 125 mmol/L respectively. Mild to severe hypernatremia were defined as serum sodium concentration > 145, > 150, and > 155 mmol/L respectively. Borderline hyponatremia and hypernatremia were defined as serum sodium concentration between 135 and 137 mmol/L or 143 and 145 respectively.A total of 11,125 patients were included in this study. Among these patients, 3,047 (27.4%) had mild to severe hyponatremia at ICU admission, 2,258 (20.3%) had borderline hyponatremia at ICU admission, 1,078 (9.7%) had borderline hypernatremia and 877 (7.9%) had mild to severe hypernatremia. After adjustment for confounder, both moderate and severe hyponatremia (subdistribution hazard ratio (sHR) 1.82, 95% CI 1.002 to 1.395 and 1.27, 95% CI 1.01 to 1.60 respectively) were associated with day-30 mortality. Similarly, mild, moderate and severe hypernatremia (sHR 1.34, 95% CI 1.14 to 1.57; 1.51, 95% CI 1.15 to 1.99; and 2.64, 95% CI 2.00 to 3.81 respectively) were independently associated with day-30 mortality.One-third of critically ill patients had a mild to moderate dysnatremia at ICU admission. Dysnatremia, including mild changes in serum sodium concentration, is an independent risk factor for hospital mortality and should not be neglected.Dysnatremia is a common finding at ICU admission [1-3]. Abnormal serum sodium concentrations are known to adversely affect physiologic function and an increasing body of evidence suggests that dysnatremia may be associated with adverse outcome [1-4]. Critically ill patients are particularly exposed to dysnatremia due to the nature of the disease leading to ICU admission and to lack of free access to water [2,4,5]. Up to one-third of critically ill patients have a dys
Acute respiratory failure in kidney transplant recipients: a multicenter study
Emmanuel Canet, David Osman, Jérome Lambert, Christophe Guitton, Anne-Elisabeth Heng, Laurent Argaud, Kada Klouche, Georges Mourad, Christophe Legendre, Jean-Fran?ois Timsit, Eric Rondeau, Maryvonne Hourmant, Antoine Durrbach, Denis Glotz, Bertrand Souweine, Beno?t Schlemmer, Elie Azoulay
Critical Care , 2011, DOI: 10.1186/cc10091
Abstract: We conducted a retrospective observational study in nine transplant centers of consecutive kidney transplant recipients admitted to the intensive care unit (ICU) for ARF from 2000 to 2008.Of 6,819 kidney transplant recipients, 452 (6.6%) required ICU admission, including 200 admitted for ARF. Fifteen (7.5%) of these patients had combined kidney-pancreas transplantations. The most common causes of ARF were bacterial pneumonia (35.5%), cardiogenic pulmonary edema (24.5%) and extrapulmonary acute respiratory distress syndrome (ARDS) (15.5%). Pneumocystis pneumonia occurred in 11.5% of patients. Mechanical ventilation was used in 93 patients (46.5%), vasopressors were used in 82 patients (41%) and dialysis was administered in 104 patients (52%). Both the in-hospital and 90-day mortality rates were 22.5%. Among the 155 day 90 survivors, 115 patients (74.2%) were dialysis-free, including 75 patients (65.2%) who recovered prior renal function. Factors independently associated with in-hospital mortality were shock at admission (odds ratio (OR) 8.70, 95% confidence interval (95% CI) 3.25 to 23.29), opportunistic fungal infection (OR 7.08, 95% CI 2.32 to 21.60) and bacterial infection (OR 2.53, 95% CI 1.07 to 5.96). Five factors were independently associated with day 90 dialysis-free survival: renal Sequential Organ Failure Assessment (SOFA) score on day 1 (OR 0.68/SOFA point, 95% CI 0.52 to 0.88), bacterial infection (OR 0.43, 95% CI 0.21 to 0.90), three or four quadrants involved on chest X-ray (OR 0.44, 95% CI 0.21 to 0.91), time from hospital to ICU admission (OR 0.98/day, 95% CI 0.95 to 0.99) and oxygen flow at admission (OR 0.93/liter, 95% CI 0.86 to 0.99).In kidney transplant recipients, ARF is associated with high mortality and graft loss rates. Increased Pneumocystis and bacterial prophylaxis might improve these outcomes. Early ICU admission might prevent graft loss.Kidney transplants account for about two-thirds of all solid organ transplants [1]. In patients with e
Minimum Penalized Hellinger Distance for Model Selection in Small Samples  [PDF]
Papa Ngom, Bertrand Ntep
Open Journal of Statistics (OJS) , 2012, DOI: 10.4236/ojs.2012.24045
Abstract: In statistical modeling area, the Akaike information criterion AIC, is a widely known and extensively used tool for model choice. The φ-divergence test statistic is a recently developed tool for statistical model selection. The popularity of the divergence criterion is however tempered by their known lack of robustness in small sample. In this paper the penalized minimum Hellinger distance type statistics are considered and some properties are established. The limit laws of the estimates and test statistics are given under both the null and the alternative hypotheses, and approximations of the power functions are deduced. A model selection criterion relative to these divergence measures are developed for parametric inference. Our interest is in the problem to testing for choosing between two models using some informational type statistics, when independent sample are drawn from a discrete population. Here, we discuss the asymptotic properties and the performance of new procedure tests and investigate their small sample behavior.
Relativistic Gauge Invariant Wave Equation of the Electron-Neutrino  [PDF]
Claude Daviau, Jacques Bertrand
Journal of Modern Physics (JMP) , 2014, DOI: 10.4236/jmp.2014.511102
Abstract:

With the right and the left waves of an electron, plus the left wave of its neutrino, we write the tensorial densities coming from all associations of these three spinors. We recover the wave equation of the electro-weak theory. A new non linear mass term comes out. The wave equation is form invariant, then relativistic invariant, and it is gauge invariant under the U(1)×SU(2), Lie group of electro-weak interactions. The invariant form of the wave equation has the Lagrangian density as real scalar part. One of the real equations equivalent to the invariant form is the law of conservation of the total current.

A Wave Equation including Leptons and Quarks for the Standard Model of Quantum Physics in Clifford Algebra  [PDF]
Claude Daviau, Jacques Bertrand
Journal of Modern Physics (JMP) , 2014, DOI: 10.4236/jmp.2014.518210
Abstract:

A wave equation with mass term is studied for all fermionic particles and antiparticles of the first generation: electron and its neutrino, positron and antineutrino, quarks u and d with three states of color and antiquarks \"\" and \"\". This wave equation is form invariant under the \"\" group generalizing the relativistic invariance. It is gauge invariant under the U(1)×SU(2)×SU(3) group of the standard model of quantum physics. The wave is a function of space and time with value in the Clifford algebra Cl1,5. Then many features of the standard model, charge conjugation, color, left waves, and Lagrangian formalism, are obtained in the frame of the first quantization.

Geometry of the Standard Model of Quantum Physics  [PDF]
Claude Daviau, Jacques Bertrand
Journal of Applied Mathematics and Physics (JAMP) , 2015, DOI: 10.4236/jamp.2015.31007
Abstract:

General relativity links gravitation to the structure of our space-time. Nowadays physics knows four types of interactions: Gravitation, electromagnetism, weak interactions, strong interactions. The theory of everything (ToE) is the unification of these four domains. We study several necessary cornerstones for such a theory: geometry and mathematics, adapted manifolds on the real domain, Clifford algebras over tangent spaces of these manifolds, the real Lagrangian density in connection with the standard model of quantum physics. The geometry of the standard model of quantum physics uses three Clifford algebras. The algebra \"\"?of the 3-dimensional physical space is sufficient to describe the wave of the electron. The algebra \"\"of space-time is sufficient to describe the wave of the pair electron-neutrino. A greater space-time with two additional dimensions of space generates the algebra \"\" . It is sufficient to get the wave equation for all fermions, electron, its neutrino and quarks u and d of the first generation, and the wave equations for the two other generations. Values of these waves allow defining, in each point of space-time, geometric transformations from one intrinsic manifold of space-time into the usual manifold. The Lagrangian density is the scalar part of the wave equation.

Left Chiral Solutions for the Hydrogen Atom of the Wave Equation for Electron + Neutrino  [PDF]
Claude Daviau, Jacques Bertrand
Journal of Modern Physics (JMP) , 2015, DOI: 10.4236/jmp.2015.611166
Abstract: The resolution of our wave equation for electron + neutrino is made in the case of the H atom. From two non-classical potentials, we get chiral solutions with the same set of quantum numbers and the same energy levels as those coming from the Dirac equation for the lone electron. These chiral solutions are available for each electronic state in any atom. We discuss the implications of these new potentials.
Electro-Weak Gauge, Weinberg-Salam Angle  [PDF]
Claude Daviau, Jacques Bertrand
Journal of Modern Physics (JMP) , 2015, DOI: 10.4236/jmp.2015.614215
Abstract: The main aim of this paper is to explain why the Weinberg-Salam angle in the electro-weak gauge group satisfies \"\". We study the gauge potentials of the electro-weak gauge group from our wave equation for electron + neutrino. These potentials are space-time vectors whose components are amongst the tensor densities without derivative built from the three chiral spinors of the wave. The \"\"?gauge invariance allows us to identify the four potential space-time vectors of the electro-weak gauge to four of the nine possible vectors. One and only one of the nine derived bivector fields is the massless electromagnetic field. Putting back the four potentials linked to the spinor wave into the wave equation we get simplified equations. From the properties of the second-order wave equation we obtain the Weinberg-Salam angle. We discuss the implications of the simplified equations, obtained without second quantification, on mass, charge and gauge invariance. Chiral gauge, electric gauge and weak gauge are simply linked.
Symbolic calculus on the time-frequency half-plane
J. Bertrand,P. Bertrand
Physics , 1997, DOI: 10.1063/1.532484
Abstract: The study concerns a special symbolic calculus of interest for signal analysis. This calculus associates functions on the time-frequency half-plane f>0 with linear operators defined on the positive-frequency signals. Full attention is given to its construction which is entirely based on the study of the affine group in a simple and direct way. The correspondence rule is detailed and the associated Wigner function is given. Formulas expressing the basic operation (star-bracket) of the Lie algebra of symbols, which is isomorphic to that of the operators, are obtained. In addition, it is shown that the resulting calculus is covariant under a three-parameter group which contains the affine group as subgroup. This observation is the starting point of an investigation leading to a whole class of symbolic calculi which can be considered as modifications of the original one.
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