26 research outputs found

    Hyperoxemia and excess oxygen use in early acute respiratory distress syndrome : Insights from the LUNG SAFE study

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    Publisher Copyright: ¬© 2020 The Author(s). Copyright: Copyright 2020 Elsevier B.V., All rights reserved.Background: Concerns exist regarding the prevalence and impact of unnecessary oxygen use in patients with acute respiratory distress syndrome (ARDS). We examined this issue in patients with ARDS enrolled in the Large observational study to UNderstand the Global impact of Severe Acute respiratory FailurE (LUNG SAFE) study. Methods: In this secondary analysis of the LUNG SAFE study, we wished to determine the prevalence and the outcomes associated with hyperoxemia on day 1, sustained hyperoxemia, and excessive oxygen use in patients with early ARDS. Patients who fulfilled criteria of ARDS on day 1 and day 2 of acute hypoxemic respiratory failure were categorized based on the presence of hyperoxemia (PaO2 > 100 mmHg) on day 1, sustained (i.e., present on day 1 and day 2) hyperoxemia, or excessive oxygen use (FIO2 ‚Č• 0.60 during hyperoxemia). Results: Of 2005 patients that met the inclusion criteria, 131 (6.5%) were hypoxemic (PaO2 < 55 mmHg), 607 (30%) had hyperoxemia on day 1, and 250 (12%) had sustained hyperoxemia. Excess FIO2 use occurred in 400 (66%) out of 607 patients with hyperoxemia. Excess FIO2 use decreased from day 1 to day 2 of ARDS, with most hyperoxemic patients on day 2 receiving relatively low FIO2. Multivariate analyses found no independent relationship between day 1 hyperoxemia, sustained hyperoxemia, or excess FIO2 use and adverse clinical outcomes. Mortality was 42% in patients with excess FIO2 use, compared to 39% in a propensity-matched sample of normoxemic (PaO2 55-100 mmHg) patients (P = 0.47). Conclusions: Hyperoxemia and excess oxygen use are both prevalent in early ARDS but are most often non-sustained. No relationship was found between hyperoxemia or excessive oxygen use and patient outcome in this cohort. Trial registration: LUNG-SAFE is registered with ClinicalTrials.gov, NCT02010073publishersversionPeer reviewe

    Thermochronology, geochronology and geochemistry of the Western and Central cordilleras and Sierra Nevada de Santa Marta, Colombia: the tectonic evolution of NW South America

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    Ce projet de thèse présente des données géochronologiques (U-Pb de zircon), thermochronologiques (40Ar/39Ar, traces de fission et (U-Th)/He dans des apatites et des zircons) et géochimiques de différents types de roches se situant dans les cordillères occidentale, centrale, et dans la vallée de Cauca-Patía de la Colombie, de la frontière équatorienne méridionale à la prolongation septentrionale des cordillères, ainsi que des données thermochronologiques de basse température de roches provenant de la Sierra Nevada de Santa Marta (nord de la Colombie). On essaye de caractériser le cadre tectonique dans lequel les principales unités géologiques ont été formées et d'interpréter l'histoire de refroidissement dans les cordillères centrale et occidentale colombienne, qui sont en lien avec les événements tectoniques du Crétacé inférieur au Miocène tardif. Les évidences présentées nous permettent d'identifier l'origine des événements de refroidissement et contraint les forces qui ont modelé les Andes colombiennes

    Insights into the Thermal History of North-Eastern Switzerland‚ÄĒApatite Fission Track Dating of Deep Drill Core Samples from the Swiss Jura Mountains and the Swiss Molasse Basin

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    This work presents new apatite fission track LA‚ÄďICP‚ÄďMS (Laser Ablation Inductively Coupled Plasma Mass Spectrometry) data from Mid‚ÄďLate Paleozoic rocks, which form the substratum of the Swiss Jura mountains (the Tabular Jura and the Jura fold-and-thrust belt) and the northern margin of the Swiss Molasse Basin. Samples were collected from cores of deep boreholes drilled in North Switzerland in the 1980s, which reached the crystalline basement. Our thermochronological data show that the region experienced a multi-cycle history of heating and cooling that we ascribe to burial and exhumation, respectively. Sedimentation in the Swiss Jura Mountains occurred continuously from Early Triassic to Early Cretaceous, leading to the deposition of maximum 2 km of sediments. Subsequently, less than 1 km of Lower Cretaceous and Upper Jurassic sediments were slowly eroded during the Late Cretaceous, plausibly as a consequence of the northward migration of the forebulge of the neo-forming North Alpine Foreland Basin. Following this event, the whole region remained relatively stable throughout the Paleogene. Our data show that the Tabular Jura region resumed exhumation at low rates in early‚Äďmiddle Miocene times (‚Čą20‚Äď15 Ma), whereas exhumation in the Jura fold-and-thrust belt probably re-started later, in the late Miocene (‚Čą10‚Äď5 Ma). Erosional exhumation likely continues to the present day. Despite sampling limitations, our thermochronological data record discrete periods of slow cooling (rates of about 1¬įC/My), which might preclude models of elevated cooling (due to intense erosion) in the Jura Mountains during the Miocene. The denudation (‚Čą1 km) of the Tabular Jura region and the Jura fold-and-thrust belt (‚Čą500 m) has provided sediments to the Swiss Molasse Basin since at least 20 Ma. The southward migration of deformation in the Jura mountains suggests that the molasse basin started to uplift and exhume only after 5 Ma, as suggested also by previous authors. The data presented here show that the deformation of the whole region is occurring in an out-of-sequence trend, which is more likely associated with the reactivation of thrust faults beneath the foreland basin. This deformation trend suggests that tectonics is the most determinant factor controlling denudation and exhumation of the region, whereas the recently proposed ‚Äúclimate-induced exhumation‚ÄĚ mechanism might play a secondary rol