Can the impact of bed closure in intensive care units be reliably monitored?

Objective: To assess the properties of various indicators aimed at monitoring the impact on the activity and patient outcome of a bed closure in a surgical intensive care unit (ICU). Design: Comparison before and after the intervention. Setting: A surgical ICU at a university hospital. Patients: All patients admitted to the unit over two periods of 10months. Intervention: Closure of one bed out of 17. Measurements and results: Activity and outcome indicators in the ICU and the structures upstream from it (emergency department, operative theater, recovery room) and downstream from it (intermediate care units). After the bed closure, the monthly medians of admitted patients and ICU hospital days increased from 107 (interquartile range 94-112) to 113 (106-121, P=0.07) and from 360 (325-443) to 395 (345-436, P=0.48), respectively, along with the linear trend observed in our institution. All indicators of workload, patient severity, and outcome remained stable except for SAPS II score, emergency admissions, and ICU readmissions, which increased not only transiently but also on a mid-term basis (10months), indicating that the process of patient care delivery was no longer predictable. Conclusions: Health care systems, including ICUs, are extraordinary flexible, and can adapt to multiple external constraints without altering commonly used activity and outcome indicators. It is therefore necessary to set up multiple indicators to be able to reliably monitor the impact of external interventions and intervene rapidly when the system is no longer under contro

Local and average diffusion of nanosolutes in agarose gel: the effect of the gel/solution interface structure

International audienc

Size Effects on Diffusion Processes within Agarose Gels

To investigate diffusion processes in agarose gel, nanoparticles with sizes in the range between 1 and 140 nm have been tested by means of fluorescence correlation spectroscopy. Understanding the diffusion properties in agarose gels is interesting, because such gels are good models for microbial biofilms and cells cytoplasm. The fluorescence correlation spectroscopy technique is very useful for such investigations due to its high sensitivity and selectivity, its excellent spatial resolution compared to the pore size of the gel, and its ability to probe a wide range of sizes of diffusing nanoparticles. The largest hydrodynamic radius (R(c)) of trapped particles that displayed local mobility was estimated to be 70 nm for a 1.5% agarose gel. The results showed that diffusion of particles in agarose gel is anomalous, with a diverging fractal dimension of diffusion when the large particles become entrapped in the pores of the gel. The latter situation occurs when the reduced size (R(A)/R(c)) of the diffusing particle, A, is >0.4. Variations of the fractal exponent of diffusion (d(w)) with the reduced particle size were in agreement with three-dimensional Monte Carlo simulations in porous media. Nonetheless, a systematic offset of d(w) was observed in real systems and was attributed to weak nonelastic interactions between the diffusing particles and polymer fibers, which was not considered in the Monte Carlo simulations

Interface Adaptable de Requêtes pour un Service de Métadonnées

AEGC 2005, vol. RNTI-E-5Extraction des connaissances : Etat et perspectives (Ateliers de la conférence EGC'2005)Dans le cadre d'un projet pluridisciplinaire relatif à la gestionintégrée du littoral (projet Syscolag), nous proposons un système de mutualisationde ressources et de connaissances. Ce système repose sur unservice de métadonnées, une base de données inventaire d'objets géographiquesde référence et un vocabulaire thématique co-construit par l'ensembledes partenaires. L'accès aux ressources partagées est guidé par uneinterface adaptable au gré de l'usage et axée sur des critères de recherchethématique, spatiaux et temporels

Interface Adaptable de Requêtes pour un Service de Métadonnées

AEGC 2005, vol. RNTI-E-5Extraction des connaissances : Etat et perspectives (Ateliers de la conférence EGC'2005)Dans le cadre d'un projet pluridisciplinaire relatif à la gestionintégrée du littoral (projet Syscolag), nous proposons un système de mutualisationde ressources et de connaissances. Ce système repose sur unservice de métadonnées, une base de données inventaire d'objets géographiquesde référence et un vocabulaire thématique co-construit par l'ensembledes partenaires. L'accès aux ressources partagées est guidé par uneinterface adaptable au gré de l'usage et axée sur des critères de recherchethématique, spatiaux et temporels

Factors affecting the flux of macromolecular, labile, metal complexes at consuming interfaces, in water and inside agarose gel: SSCP study and environmental implications

International audienceIn environmental processes, the contribution of macromolecular or colloidal metal complexes to the overall diffusion flux of metal may be of major importance. For labile complexes, the computation of such flux is based on the concept of average diffusion coefficient, which has only been checked systematically with small size ligands and in aqueous solution. This concept is checked here, both in aqueous solution and in agarose hydrogel, with large size macromolecules: dextrans of molar masses 10 000, 40 000 and 464 000, modified to introduce fluorescent or complexing (aspartate) moieties in their structure have been used. Their diffusion properties in water and agarose gel are determined by fluorescence correlation spectroscopy (FCS). The complexing and diffusive properties of their Pb(II) complexes in water and agarose hydrogel are also determined by scanning stripping chronopotentiometry (SSCP). It is shown that both in water and gel, the concept of average diffusion coefficient is applicable to compute the flux of these labile complexes at consuming interfaces. The results also show that the three ligands and their Pb-complexes diffuse as spherical coils, in water and in the gel, in accordance with other recent results. The implications of these results, in environmental applications, in particular in biouptake, and for the development of in situ sensors for environmental monitoring, are discussed, as well as the optimum conditions of voltammetric measurements with get integrated microelectrode (GIME) in natural media containing colloidal complexes. In particular it is shown that, provided the gel is correctly preequilibrated with the test solution, and its thickness is larger than 150 mu m, diffusion/reaction in the test solution do not influence the voltammetric flux at microelectrodes in the gel. The same conclusion is applicable to microorganisms inside biofilms. (c) 2006 Elsevier B.V. All rights reserved

Système d'Information pour la Gestion Intégrée des Zones Côtières

International audienc