High-flow nasal cannula oxygen therapy alone or with non-invasive ventilation during the weaning period after extubation in ICU: the prospective randomised controlled HIGH-WEAN protocol

INTRODUCTION: Recent practice guidelines suggest applying non-invasive ventilation (NIV) to prevent postextubation respiratory failure in patients at high risk of extubation failure in intensive care unit (ICU). However, such prophylactic NIV has been only a conditional recommendation given the low certainty of evidence. Likewise, high-flow nasal cannula (HFNC) oxygen therapy has been shown to reduce reintubation rates as compared with standard oxygen and to be as efficient as NIV in patients at high risk. Whereas HFNC may be considered as an optimal therapy during the postextubation period, HFNC associated with NIV could be an additional means of preventing postextubation respiratory failure. We are hypothesising that treatment associating NIV with HFNC between NIV sessions may be more effective than HFNC alone and may reduce the reintubation rate in patients at high risk. METHODS AND ANALYSIS: This study is an investigator-initiated, multicentre randomised controlled trial comparing HFNC alone or with NIV sessions during the postextubation period in patients at high risk of extubation failure in the ICU. Six hundred patients will be randomised with a 1:1 ratio in two groups according to the strategy of oxygenation after extubation. The primary outcome is the reintubation rate within the 7 days following planned extubation. Secondary outcomes include the number of patients who meet the criteria for moderate/severe respiratory failure, ICU length of stay and mortality up to day 90. ETHICS AND DISSEMINATION: The study has been approved by the ethics committee and patients will be included after informed consent. The results will be submitted for publication in peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT03121482

A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)

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Nanosecond pulsed discharge in a propane-air mixture: Ignition and energy deposition

WOS:000393412600084International audienceThe study examined the possibility of using nanosecond pulse discharges as a new ignition and assisted combustion method to solve ignition and combustion stabilization problems encountered in new combustion technologies. To better understand how temperature and the presence of radicals affect nanosecond discharge ignitions, spatiotemporal profiles of rotational and vibrational N-2(X) temperatures were measured through spontaneous Raman scattering in a lean propane-air mixture and compared with previous results obtained in air to obtain the space-and time-resolved measurements necessary to validate the kinetic modeling of the discharge in presence of hydrocarbons. The study aims to contribute to a better understanding of the initial ignition processes in stoichiometric mixture (first observed at 1 mu s) and the rapid displacement of the flame front in propane-air mixtures. In the analyzed propane-air mixture, the gas heated slightly more rapidly than in air. This temperature increase might have occurred in the release of energy resulting from dissociation of propane due to quenching by metastable species. The presence of traces of CO confirmed this assumption. The energy transfer processes were identical in all other respects and occurred over the same time scales in air and in the propane-air mixture. Once the flame in the stoichiometric mixture was ignited, it propagated through a cylindrical channel whose diameter was identical to that of the volume of gas heated to above 900 K in the lean propane-air mixture. This early ignition and the spreading of the flame kernel demonstrate the combined effect of radicals and temperature on the nanosecond discharge ignition process. The resulting new database makes it possible to validate simulations of the vibrational kinetics involved in nanosecond discharges of a lean propane-air mixture and provides a first step toward modeling flame initiation. (C) 2016 by The Combustion Institute. Published by Elsevier Inc

Prognostic significance of central venous-to-arterial carbon dioxide difference during the first 24 hours of septic shock in patients with and without impaired cardiac function

IF 6.238International audienceObjective: To investigate the prognostic significance of central venous-to-arterial carbon dioxide difference (cv-art CO2 gap) during septic shock in patients with and without impaired cardiac function.Methods: We performed a prospective cohort study in 10 French intensive care units. Patients suffering from septic shock were assigned to the impaired cardiac function group (‘cardiac group’, n=123) if they had atrial fibrillation (AF) and/or left ventricular ejection fraction (LVEF) 0.9 kPa at 12 h had a higher risk of day 28 mortality (hazard ratio=3.18; P=0.0049). Among the 59 patients in the cardiac group with mean arterial pressure (MAP) ≥65 mm Hg, central venous pressure (CVP) ≥8 mm Hg and central venous oxygen saturation (ScvO2) ≥70% at 12 h, those with a high cv-art CO2 gap (>0.9 kPa; n=19) had a higher day 28 mortality (37% vs. 13%; P=0.042). In the non-cardiac group, a high cv-art CO2 gap was not linked to a higher risk of day 28 death, whatever the threshold value of the cv-art CO2 gap.Conclusion: Patients with septic shock and with AF and/or low LVEF were more prone to a persistent high cv-art CO2 gap, even when initial resuscitation succeeded in normalizing MAP, CVP, and ScvO2. In these patients, a persistent high cv-art CO2 gap at 12 h was significantly associated with higher day 28 mortality