Littérature scientifique sur le sujet « Ventilation – Mer »
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Articles de revues sur le sujet "Ventilation – Mer"
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ORJIME, Emmanuel Verem, Benjamin G. AHULE, Godwin A. AKPEHE, Solomon GBAKA, Victor Ushahemba IJIRSHAR, and Kafayat O. ZAKA. "Indigenous Preservation Practices and Shelf Life of Stored Yams in Benue State, Nigeria: Implication for Post-Harvest Management and Food Security." MANAGEMENT AND ECONOMICS REVIEW 9, no. 1 (2024): 25–40. http://dx.doi.org/10.24818/mer/2024.01-02.
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Several empirical studies have been conducted on the relationship between indigenous practices and yam tuber preservation. However, there is a lack of empirical evidence regarding the extent of effectiveness of the existing indigenous preservation practices in reducing yam postharvest losses with regard to prolonging the shelf life, which underscores an existing gap in knowledge. The purpose of this study is to examine the extent of effectiveness of existing indigenous preservation practices in prolonging the shelf life of stored yam tubers in Benue State, Nigeria, using a cross-sectional survey design based on a proportional sampling technique involving 255 respondents. The result of the chi-square test shows the probability value of 0.000<0.05; hence, the study rejected the null hypothesis. A symmetric Phi value of 0.635 was obtained, showing a positive association between the variables. Thus, application of the existing indigenous yam preservation practices led to the overall improvement in the shelf life of stored yams by 34%. The study recommends that government and nongovernmental organizations should provide both financial and technical assistance to rural yam farming families, in the form of loan facilities. Yam farmers should also form cooperative societies in order to borrow more funds from financial institutions. This will boost the expansion of storehouses to accommodate the increasing quantity of yam tubers harvested, provide good ventilation in stores, and enhance free traffic during the removal of sprout development in storehouses to avert yam tuber postharvest losses and prolong the shelf life of the stored yam tubers in the study area.
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Ricard, Jean-Damien, Fadia Dib, Marina Esposito-Farese, Jonathan Messika, and Christophe Girault. "Comparison of high flow nasal cannula oxygen and conventional oxygen therapy on ventilatory support duration during acute-on-chronic respiratory failure: study protocol of a multicentre, randomised, controlled trial. The ‘HIGH-FLOW ACRF’ study." BMJ Open 8, no. 9 (2018): e022983. http://dx.doi.org/10.1136/bmjopen-2018-022983.
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IntroductionThis study protocol describes a trial designed to investigate whether high-flow heated and humidified nasal oxygen (HFHO) therapy in patients with hypercapnic acute respiratory failure (ARF) reduces the need of non-invasive ventilation (NIV).Methods and analysisThis is an open-label, superiority, international, parallel-group, multicentre randomised controlled two-arm trial, with an internal feasibility pilot phase. 242 patients with hypercapnic ARF requiring NIV admitted to an intensive care unit, an intermediate care or a respiratory care unit will be randomised in a 1:1 ratio to receive HFHO or standard oxygen in between NIV sessions. Randomisation will be centralised and stratified by centre and pH at admission (pH ≤7.25 or >7.25). The primary outcome will be the number of ventilator-free days (VFDs) and alive at day 28 postrandomisation. The secondary outcomes will encompass parameters related to the VFDs, comfort and tolerance variables, hospital length of stay and mortality. VFDs at 28 days postrandomisation will be compared between the two groups by Wilcoxon-Mann-Whitney two-sample rank-sum test in the intention-to-treat population. A sensitivity analysis will be conducted in the population of patients for whom the criteria of switching from NIV to spontaneous breathing, or conversely, are not strictly verified.Ethics and disseminationThe protocol has been approved by theComité de Protection des Personnes(CPP)Sud-Ouest & Outre-Mer IV(ref CPP17-049a/2017-A01830-53) and will be carried out in accordance with the Declaration of Helsinki and Good Clinical Practice guidelines. A trial steering committee will oversee the progress of the study. Findings will be disseminated through national and international scientific conferences, and publication in peer-reviewed journals.Trial registration numberNCT03406572.
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Heglum, Margareth, Marita Flasnes, and Susan Saga. "Barrierer for å ta i bruk høy PEEP og lungerekruttering ved generell anestesi til pasienter med fedme." Inspira 15, no. 2 (2020): 16–24. http://dx.doi.org/10.23865/inspira.v15.2764.
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Merk: Følgende artikkel ble utgitt før tidsskriftet gikk over til åpen digital publisering. Vedlagte PDF er hentet fra trykt utgave, se egen informasjon om opphavsrett på artikkelen.
 Bakgrunn: Grunnet økende fedme i befolkningen, vil en større andel av pasienter i generell anestesi være pasienter med fedme. Generell anestesi og mekanisk ventilering fører til at omtrent 90 % utvikler atelektaser. Pasienter med fedme får atelektaser tidligere og i større grad enn den normalvektige, dette kan vise seg som redusert gassutveksling og hypoksi peroperativt. Dette øker risikoen for postoperative lungekomplikasjoner. Nyere forskningslitteratur anbefaler bruk av ventileringsstrategiene høyt positivt endeekspiratorisk trykk (PEEP) og lungerekruttering (LR) for å begrense utviklingen av atelektaser hos denne pasientgruppen. Vi vet imidlertid lite om hvordan bruken av disse ventileringsstrategiene er blant anestesisykepleierei Norge.
 Hensikt: Å undersøke hvilke aspekter som påvirker anestesisykepleierens bruk av høy PEEP og LR peroperativt til pasienter med fedme i generell anestesi.
 Metode: Studien har et kvalitativt design. Det ble gjennomført individuelle, semistrukturerte intervju med 15 anestesisykepleiere fra to sykehus. Datamaterialet ble analysert ved hjelp av Graneheim og Lundmans kvalitative innholdsanalyse.
 Resultat: Studien viser at opplevelse av egen trygghet i yrkesutøvelsen samt kulturelle og organisatoriske forhold påvirker anestesisykepleierens bruk av høy PEEP og LR. Anestesisykepleierne har varierende mengdetrening i bruk av høy PEEP og LR. Andre og mer kjente strategier prioriteres ofte først hos de med lite mengdetrening. Samarbeidet med legene synes å være bra og i liten grad en hemmende faktor. Alle informantene mener bruk av høy PEEP og LR er en oppgave for anestesisykepleier hos pasienter klassifisert i ASA 1 eller ASA 2, men peker på at det mangler fagprosedyre/retningslinje knyttet til anvendelse av høy PEEP og LR.
 Konklusjon: Studien viser at både individuelle, kulturelle og organisatoriske aspekter påvirker anestesisykepleiernes bruk av høy PEEP og LR hos pasienter med fedme i generell anestesi. Alt tatt i betraktning kan det å sette ventileringsstrategiene på dagsorden føre til en økt bevissthet om bruken som igjen kan føre til utvidet bruk av ventileringsstrategiene.
 English abstract
 Introduction: Increasing obesity in the population means that the proportion of obese patients undergoing general anesthesia is expected to increase. General anesthesia and mechanicalventilation cause approximately 90% of patients to develop atelectasis. Obese patients develop atelectasis earlier, and to a greater extent than patients with a body mass index within the normal range. Recent research literature recommends the use of ventilation strategies - high positive end-expiratory pressure (PEEP) and pulmonary recirculation (LR) - to prevent the development of atelectasis in this cohort of patients. However, we have limited knowledge regarding how these ventilation strategies are implemented in clinical practice among nurse anesthetics in Norway.
 Purpose: To investigate which aspects that affect the use of high PEEP and LR perioperatively for patients with obesity in general anesthesia.
 Method: A qualitative study conducted using individual semi-structured interviews. 15 nurse anesthetists from two different hospitals were interviewed. The data was analyzed using qualitative content analysis.
 Result: The nurse anesthetists’ use of high PEEP and LR is affected by (1) the experience of self-confidence in professional practice and (2) organizational conditions. The amount of training within the use of high PEEP and LR varies among the anesthetic nurses interviewed, affecting the extent to which these strategies are being implemented. Other, more well-known strategies are often prioritized first. The collaboration between nurses and anesthesiologists is well functioning and cannot be considered an inhibitory factor. All informants express that the use of high PEEP and LR is a task in anesthesia nursing for patients classified within patient groups ASA 1 or ASA 2. The results however demonstrate a lack of implemented clinical procedures and guidelines regarding the use of high PEEP and LR.
 Conclusion: This study shows that both individual and organisational aspects affect the nurse anaesthetists use of high PEEP and LR for patients with obesity in general anesthesia. Increasing the nurses’ self-confidence through both training and systematic implementation is critical to increase the use of recommended ventilation strategies.
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Nikolla, Dhimitri A., Brandon J. Kramer, and Jestin N. Carlson. "A Cross-Over Trial Comparing Conventional to Compression-Adjusted Ventilations with Metronome-Guided Compressions." Prehospital and Disaster Medicine 34, no. 02 (2019): 220–23. http://dx.doi.org/10.1017/s1049023x19000098.
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Introduction:Hyperventilation during cardiopulmonary resuscitation (CPR) negatively affects cardiopulmonary physiology. Compression-adjusted ventilations (CAVs) may allow providers to deliver ventilation rates more consistently than conventional ventilations (CVs). This study sought to compare ventilation rates between these two methods during simulated cardiac arrest.Null Hypothesis:That CAV will not result in different rates than CV in simulated CPR with metronome-guided compressions.Methods:Volunteer Basic Life Support (BLS)-trained providers delivered bag-valve-mask (BVM) ventilations during simulated CPR with metronome-guided compressions at 100 beats/minute. For the first 4-minute interval, volunteers delivered CV. Volunteers were then instructed on how to perform CAV by delivering one breath, counting 12 compressions, and then delivering a subsequent breath. They then performed CAV for the second 4-minute interval. Ventilation rates were manually recorded. Minute-by-minute ventilation rates were compared between the techniques.Results:A total of 23 volunteers were enrolled with a median age of 36 years old and with a median of 14 years of experience. Median ventilation rates were consistently higher in the CV group versus the CAV group across all 1-minute segments: 13 vs 9, 12 vs 8, 12 vs 8, and 12 vs 8 for minutes one through four, respectively (P &lt;.01, all). Hyperventilation (&gt;10 breaths per minute) occurred 64% of the time intervals with CV versus one percent with CAV (P &lt;.01). The proportion of time which hyperventilation occurred was also consistently higher in the CV group versus the CAV group across all 1-minute segments: 78% vs 4%, 61% vs 0%, 57% vs 0%, and 61% vs 0% for minutes one through four, respectively (P &lt;.01, all).Conclusions:In this simulated model of cardiac arrest, CAV had more accurate ventilation rates and fewer episodes of hyperventilation compared with CV.Nikolla DA, Kramer BJ, Carlson JN. A cross-over trial comparing conventional to compression-adjusted ventilations with metronome-guided compressions. Prehosp Disaster Med. 2019;34(2):220–223
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Lacerda, Rodrigo Silva, Fernando Cesar Anastácio de Lima, Leonardo Pereira Bastos, et al. "Benefits of Manometer in Non-Invasive Ventilatory Support." Prehospital and Disaster Medicine 32, no. 6 (2017): 615–20. http://dx.doi.org/10.1017/s1049023x17006719.
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AbstractIntroductionEffective ventilation during cardiopulmonary resuscitation (CPR) is essential to reduce morbidity and mortality rates in cardiac arrest. Hyperventilation during CPR reduces the efficiency of compressions and coronary perfusion.ProblemHow could ventilation in CPR be optimized? The objective of this study was to evaluate non-invasive ventilator support using different devices.MethodsThe study compares the regularity and intensity of non-invasive ventilation during simulated, conventional CPR and ventilatory support using three distinct ventilation devices: a standard manual resuscitator, with and without airway pressure manometer, and an automatic transport ventilator. Student’s t-test was used to evaluate statistical differences between groups. P values <.05 were regarded as significant.ResultsPeak inspiratory pressure during ventilatory support and CPR was significantly increased in the group with manual resuscitator without manometer when compared with the manual resuscitator with manometer support (MS) group or automatic ventilator (AV) group.ConclusionThe study recommends for ventilatory support the use of a manual resuscitator equipped with MS or AVs, due to the risk of reduction in coronary perfusion pressure and iatrogenic thoracic injury during hyperventilation found using manual resuscitator without manometer.LacerdaRS, de LimaFCA, BastosLP, VincoAF, SchneiderFBA, CoelhoYL, FernandesHGC, BacalhauJMR, BermudesIMS, da SilvaCF, da SilvaLP, PezatoR. Benefits of manometer in non-invasive ventilatory support. Prehosp Disaster Med. 2017;32(6):615–620.
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Ge, Wu, Wu Wei, Pan Shuang, Zheng Yan-Xia, and Lv Ling. "Nasointestinal tube in mechanical ventilation patients is more advantageous." Open Medicine 14, no. 1 (2019): 426–30. http://dx.doi.org/10.1515/med-2019-0045.
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AbstractObjectiveTo assess the effects of two different nutritional mode on the occurrence of ventilator-associated pneumonia (VAP) in patients on mechanical ventilation.Methods70 patients admitted to the ICU and under mechanical ventilation, were randomly divided into the nasointestinal tube group and nasogastric tube group. Patients from both groups received enteral nutrition, using the same nutritional agent, through intubation. The duration of stay in the ICU, duration of mechanical ventilation, incidence of VAP, nutritional state, and survival of the intestinal tract were compared between the two groups.ResultsThe duration of stay in the ICU, duration of mechanical ventilation and incidence of VAP in the nasointestinal tube group was lower than that in the nasogastric tube group (P<0.05). There was an increase in the levels of prealbumin and transferrin in the nasointestinal tube group (P<0.05). However, there were no obvious difference in the nasogastric tube group (P<0.05). The incidence of abdominal distension, diarrhea, regurgitation, aspiration, and hyperglycemia in the nasointestinal tube group was much lower than that in the nasogastric tube group (P < 0.05).ConclusionThis study showed that enteral nutrition delivery using a nasointestinal way can effectively reduce the incidence of VAP and improve the nutritional status of patients under mechanical ventilation.
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Be’eri, Eliezer, Simon Owen, Maurit Beeri, Scott R. Millis, and Arik Eisenkraft. "A Chemical-Biological-Radio-Nuclear (CBRN) Filter can be Added to the Air-Outflow Port of a Ventilator to Protect a Home Ventilated Patient From Inhalation of Toxic Industrial Compounds." Disaster Medicine and Public Health Preparedness 12, no. 6 (2018): 739–43. http://dx.doi.org/10.1017/dmp.2018.3.
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AbstractObjectivesChemical-biological-radio-nuclear (CBRN) gas masks are the standard means for protecting the general population from inhalation of toxic industrial compounds (TICs), for example after industrial accidents or terrorist attacks. However, such gas masks would not protect patients on home mechanical ventilation, as ventilator airflow would bypass the CBRN filter. We therefore evaluated in vivo the safety of adding a standard-issue CBRN filter to the air-outflow port of a home ventilator, as a method for providing TIC protection to such patients.MethodsEight adult patients were included in the study. All had been on stable, chronic ventilation via a tracheostomy for at least 3 months before the study. Each patient was ventilated for a period of 1 hour with a standard-issue CBRN filter canister attached to the air-outflow port of their ventilator. Physiological and airflow measurements were made before, during, and after using the filter, and the patients reported their subjective sensation of ventilation continuously during the trial.ResultsFor all patients, and throughout the entire study, no deterioration in any of the measured physiological parameters and no changes in measured airflow parameters were detected. All patients felt no subjective difference in the sensation of ventilation with the CBRN filter canister in situ, as compared with ventilation without it. This was true even for those patients who were breathing spontaneously and thus activating the ventilator’s trigger/sensitivity function. No technical malfunctions of the ventilators occurred after addition of the CBRN filter canister to the air-outflow ports of the ventilators.ConclusionsA CBRN filter canister can be added to the air-outflow port of chronically ventilated patients, without causing an objective or subjective deterioration in the quality of the patients’ mechanical ventilation. (Disaster Med Public Health Preparedness. 2018;12:739-743)
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Fancev, Tomislav, Davor Grgić, and Siniša Šadek. "Verification of GOTHIC Multivolume Containment Model during NPP Krško DBA LOCA." Journal of Energy - Energija 65, no. 3-4 (2022): 116–26. http://dx.doi.org/10.37798/2016653-4118.
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New containment multivolume model of NPP Krsko for GOTHIC code is developed. It is based on plant drawings and other available data. It is supported by developed SketchUp 3D containment model. The model is subdivided in volumes following physical boundaries and clearly defined flow paths. All important concrete heat structures are taken into account. Metal heat structures are based on plant’s SAR Chapter 6 licensing model. RCFC (Reactor Containment Fan Cooler) units are explicitly modelled as well as all main ventilation ducts. The model includes two trains of containment spray system. PARs (Passive Autocatalytic Recombiner) and PCFV (Passive Containment Filter Venting) filters added during plant safety upgrade project are part of the model too. It was intention to use model for both DBA (Design Basis Accident) and for DEC (Design Extended Conditions) and BDBA (Beyond Design Basis Accident) calculations. Based on the same discretization and data, and on experience acquired during GOTHIC model development and use, containment models for MELCOR and MAAP integral codes are developed too. As part of initial verification of the GOTHIC model containment DBA LOCA calculation is performed using SAR MER (Mass and Energy Release) data. The influence of different break positions on peak containment atmosphere pressure and temperature was studied. The results were compared against results obtained in single volume containment licensing model. Beside local effects due to different containment subdivision similar results are obtained when comparing containment dome from multivolume and the single volume in licensing model. Special attention was paid to distribution of water in lower part of the containment during recirculation phase. In this case much more valuable information are obtained in multivolume model with explicit volumes for main sump, recirculation sump and sump pit. Another point of interest was influence of containment spray duration on long term pressure and temperature behaviour. The intention was to study consistency of assumed different spray operation times used in safety analyses, EQ analyses and SAMGs and related consequences for plant operation during DBA LOCA.
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R. Sujatha, Anil Singh Yadav, Dilshad Khan Dilshad Arif, and Astha Gupta. "Microbial Profile and Antibiogram of Ventilator Associated Pneumonia at Tertiary Care Hospital U.P." International Journal of Current Microbiology and Applied Sciences 10, no. 11 (2021): 10–18. http://dx.doi.org/10.20546/ijcmas.2021.1011.002.
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Ventilator associated pneumonia (VAP) is a common and serious healthcare associated infection (HAI). VAP is inflammation of lung parenchyma caused by infectious agents that develops in a patient who is on a ventilator occurring 48-72 hrs or more after tracheal intubation and mechanical ventilation (MV). The risk of VAP is highest early in the course of hospital stay, and is estimated to be 3%/day during the first 5 days of ventilation, 2%/day during days 5-10 of ventilation and 1%/day after this. Aim of this study was find out the Microbial profile and antibiogram of ventilator associated pneumonia at tertiary care hospital U.P. This study was conducted in the Department of Microbiology, Rama Medical College, Hospital & Research Centre, Kanpur India from January 2016 to December 2016. A total of 100 Endotracheal aspirated samples were collected in a sterile & labelled clean dry container from the clinically suspected cases of VAP patients. Out of 100 patients 31 patients shown growth of the bacteria & considered as Ventilator Associated Pneumonia patients. And 69 patients have not shown any kind of growth. Acinetobacter baumanni, Pseudomonas aeruginosa, Enterobacter & Klebsiella Pneumoniae were the most common pathogens from both early & late onset VAP. Proper monitoring and strict implementation of infection control practices is very essential to reduce VAP in hospital setting. Also the short term use of invasive devices and judicious use of antibiotics are important in preventing VAP caused by these MDR pathogens.
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Kristoffersen, Marte, and Anne-Marthe Rustad Indregard. "Intensivsykepleieres erfaringer med kollektiv mestring av arbeidsrelatert stress." Inspira 19, no. 2 (2024): 41–55. http://dx.doi.org/10.23865/inspira.v19.6366.
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Bakgrunn: Intensivsykepleieres arbeidshverdag preges av høye faglige og relasjonelle krav. Intensivmiljøet er høyteknologisk og avansert, og arbeidspresset er stort. Tidligere studier viser at intensivsykepleiere har økt risiko for omfattende arbeidsbelastning, høy forekomst av utbrenthet og økt sykefravær, og mange ytrer et ønske om å forlate yrket. Det er behov for mer kunnskap om kollektive mestringsstrategier som bidrar til at intensivsykepleiere håndterer arbeidskravene de står overfor, og som forebygger negative konsekvenser av arbeidsrelatert stress. Hensikt: Å utforske og beskrive intensivsykepleieres erfaringer med kollektiv mestring av arbeidsrelatert stress. Metode: Kvalitativ pilotstudie. Utvalget besto av intensivsykepleiere med minst tre års erfaring. Fire individuelle semistrukturerte dybdeintervjuer ble gjennomført på to intensivavdelinger ved et universitetssykehus på Østlandet. Analysen ble utført etter Braun og Clarkes tematiske analysemetode. Resultater: Analysen resulterte i to hovedtemaer: 1) «Betydningen av handlingsberedskap i en kompleks arbeidshverdag» og 2) «Behov for sosial støtte fra kollegaer og ledere». Handlingsberedskap omfattet betydningen av akuttberedskap, rolleavklaring, fagutvikling, mestringstro og kompetanse om arbeidsrelatert stress og mestring. Videre kom det frem at en synlig og anerkjennende ledelse, felles refleksjon og ventilering med kollegaer var relevant for å oppleve kollektiv mestring. Konklusjon: Intensivsykepleierne i denne pilotstudien erfarte handlingsberedskap og sosial støtte fra kollegaer og ledere som vesentlige faktorer for kollektiv mestring av arbeidsrelatert stress. Resultatene anses som relevante og nyttige for utarbeidelse av nye og større studier. Videre forskning er nødvendig for å forstå kompleksiteten av kollektiv mestring for intensivsykepleiere. ENGLISH ABSTRACT Intensive Care Nurses’ Experiences with Collective Coping of Work-Related Stress Background: The working life of intensive care nurses are characterized by high professional and relational demands. The intensive care environment is technologically advanced and the work pressure is high. Previous studies show that intensive care nurses have an increased risk of substantial workload, high levels of burnout and sickness absence, and many are considering leaving the profession. There is a need for more knowledge about collective coping strategies helping intensive care nurses to manage the job demands and to prevent the negative consequences of workrelated stress. Purpose: To explore and describe intensive care nurses’ experiences with collective coping of work-related stress. Method: Qualitative pilot study. Our sample consisted of intensive care nurses with at least three years of experience. Four individual semi-structured in-depth interviews were conducted at two intensive care units at a university hospital in Eastern Norway. The analysis was conducted by using Braun and Clarke’s thematic analysis method. Results: The analysis resulted in two main themes: 1) “The importance of preparedness in a complex workday” and 2) “The need for social support from colleagues and leaders.” Preparedness included the importance of emergency preparedness, role clarification, professional development, self-efficacy and competence about work-related stress and coping. Furthermore, it became clear that visible and appreciative leadership, along with shared reflection and ventilation with colleagues, was relevant for experiencing collective coping. Conclusion: In this pilot study, intensive care nurses experienced preparedness and social support from colleagues and leaders as essential factors for collective coping with work-related stress. The results are considered relevant and useful for the development of new and larger studies. Further research is needed to understand the complexity of collective coping for intensive care nurses.
Thèses sur le sujet "Ventilation – Mer"
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Paillet, Jérôme. "Eau modale et ventilation océanique en Atlantique nord-est." Brest, 1996. http://www.theses.fr/1996BRES2004.
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La formation d'eau modale subpolaire en atlantique nord-est, et la ventilation de ce bassin par cette masse d'eau, sont etudies sous differents aspects. Une analyse de donnees hydrologiques recentes nous permet tout d'abord de localiser l'eau modale et d'en caracteriser les proprietes. La circulation generale dans la region est estimee en appliquant la relation geostrophique a ces memes donnees. Puis deux etudes realisees avec des modeles physiques simplifies, un modele de thermocline ventilee et un modele uni-dimensionnel lagrangien, montrent que le parametre cle qui controle la formation et la subduction de l'eau modale est le bilan annuel de flottabilite de la couche de melange hivernale. Enfin, un modele inverse de l'atlantique nord est permet de confirmer et de quantifier les processus en jeu dans ce mecanisme de ventilation oceanique
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Bodell, Erik, and Simon Åhlander. "Energianalys av byggnad med installerat ångsystem för matlagningsprocesser : Kan ånga vara mer effektivt än el för matlagning?" Thesis, Högskolan i Gävle, Energisystem, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-24232.
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Det finns ett stort behov av att minska energianvändningen i världen. Igenom att minska energibehovet så minskar den negativa miljöpåverkan. I en ständigt växande värld där det byggs i allt snabbare takt så ökar också energibehovet. Igenom att effektivisera befintliga byggnader kan energibehovet stagnera eller till och med minska trots utbyggnaden. Igenom att energieffektivisera så kan mer av den energi som används nyttjas istället för att den ska stå för onödiga förluster. Fortifikationsverket har en restaurangbyggnad de anser använder för mycket energi. Denna byggnad innehåller en restaurang som använder ett ångsystem för matproduktion, vilket gör byggnadens energisystem unikt. För att kunna minska byggnadens energianvändning kartläggs och analyseras den i denna rapport. Denna fallstudie genomförs med en litteraturstudie för att utveckla kunskaperna inom området. Sedan utförs mätningar i byggnaden som därefter analyseras och presenteras så att eventuella avvikelser och brister påpekas. Under arbetets gång upptäcktes att en säkring var felinstallerad för mätningen av elanvändningen till en av ångpannorna. Igenom att ha åtgärdat detta för att kunna fakturera rätt så spar Fortifikationsverket nästan 170 000 kr per år som den ångpannan går. Utöver detta så analyserades ångsystemet och uppskattningar gjordes för att kunna svara på om ånga är effektivare än el för matlagning. Det visar sig att ångsystemet kan vara effektivt om stor mängd mat tillagas. Med hänsyn till nätter, helger och de dagar då mindre mat tillagas så är el-utrustning effektivare eftersom att det helt stängs av när det inte används. Till skillnad från ångsystemet som måste täcka upp för förlusterna för att behålla temperatur och tryck, även när systemet inte används. Igenom att byta ut ångsystemet till motsvarande utrustning som drivs av el skulle det gå att spara 205 MWh/år, enligt uppskattningar. Ångsystemet står för 35% av byggnadens totala elanvändning och är den största posten för energianvändningen och är därför den del som fokuserats mest på. Utöver ångsystemet så analyserades övrig energianvändning för att kunna ge förslag på besparingar. Många av förslagen är grundade på vissa uppskattningar och antaganden vilket måste beaktas. Några konkreta exempel på besparingar som kan göras är att sänka inomhustemperaturen för att spara 50 MWh/år, installera tilläggsfönster för att spara upp till 140 MWh/år, installera effektivare kylaggregat – 200 MWh/år, installera bättre styrning till ventilationen – 110 MWh/år, installera bättre styrning till belysning – 40 MWh/år.<br>There is a great need to reduce energy use in the world. By reducing energy demand, this reduces the negative environmental impact. In a constantly growing world, where it is built at an ever faster pace, the energy demand also increases. By increasing energy efficiency inexisting buildings, energy requirements may stagnate or even decrease despite expansion. By increasing energy efficiency, more of the energy demand can be used instead of standing for energy losses. Fortifikationsverket has a building they believe use too much energy. This building contains a restaurant that uses a steam system to heat its food, which makes the building's energy system unique. In order to reduce the energy consumption of the building, an energy audit is completed and analyzed in this report. This case study is conducted with a literature study to develop the knowledge in the field. Then measurements in the building are performed which are subsequently analyzed and presented to indicate any deviations and deficiencies. During the work it was discovered that a fuse was incorrectly installed to measure the electricity consumption of one of the boilers. By correcting this in order to be able to bill correctly, Fortifikationsverket saves almost 170,000 SEK per year as the boiler goes. In addition to this, the steam system was analyzed and estimates were made to respond if steam is more effective than electricity for cooking. It turns out that the steam system can be effective if a large amount of food is cooked. Considering nights, weekends and days when less food is cooked, electrical equipment is more effective because it completely turns off when not in use. Unlike the steam system that has to cover the energy losses to keep temperature and pressure, even when the system is not in use. By replacing the steam system with equivalent electrical equipment, it couldsave 205 MWh/year, according to estimates.The steam system accounts for 35% of the building's total electricity demandand is the largest item for energy use and is therefore the most focused area. In addition to the steam system, other energy usage was analyzed to provide energy savings. Many of the proposals are based on certain estimates and assumptions which must be considered. Some examples of savings that can be made is lowering the indoor temperature to save 50 MWh/year, install additional windows to save up to 140 MWh/year, install more efficient cooling units -200 MWh/year, install better ventilation control systems-50 MWh/year, install better controls for indoor lighting -40 MWh/year.
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Millet, Bruno. "Tracer and model constraints on the ventilation of the deep Pacific Ocean." Electronic Thesis or Diss., université Paris-Saclay, 2024. http://www.theses.fr/2024UPASJ019.
Texte intégralRésumé :
L'océan Pacifique représente environ 50% du volume global des océans, ce qui en fait un acteur essentiel des cycles biogéochimiques globaux et de leur réponse aux perturbations. En particulier, l'océan Pacifique profond abrite des réservoirs majeurs de carbone et de nutriments, dont la taille et les variations sont largement contrôlées par les transports physiques de traceurs. Dans cette thèse, nous visons à mieux comprendre et contraindre le transport de traceurs dans l'océan Pacifique profond à travers les états climatiques. Pour cela, nous générons de nouvelles et utilisons d'anciennes observations de traceurs conservatifs, notamment les isotopes de l'oxygène, ainsi que des modèles numériques de circulation océanique. Nous montrons que le mélange isopycnale a un contrôle essentiel sur la ventilation des profondeurs moyennes du Pacifique. Un retour des eaux abyssales vers la surface est identifié dans le Pacifique subarctique moderne. Cette voie de remontée semble avoir diminué pendant le dernier maximum glaciaire, il y a environ 20 000 ans, et le Pacifique Nord profond pourrait avoir été plus fortement stratifié. Cependant, les preuves de changements nécessaires dans le sud du bassin pour expliquer cette stratification profonde restent rares. Les modèles de pointe de circulation océanique peinent à représenter les trajectoires des traceurs et les vitesses de ventilation dans le Pacifique Nord moderne, déduites des observations. Cependant, ces trajets de traceurs restent insuffisamment contraints et la dynamique sous-jacente est mal comprise. L'analyse des mesures in situ du rapport isotopique de l'oxygène 18 (18O) de l'eau de mer constitue un moyen efficace pour mieux contraindre les origines et les itinéraires des traceurs dans l'océan profond : les observations actuelles de 18O dans les océans Austral, Indien et Pacifique permettent de mieux comprendre ces itinéraires. Nous suggérons que des mesures supplémentaires de 18O à partir d'échantillons d'eau de mer modernes et de coquilles de calcite dans les carottes de sédiments fourniraient des contraintes précieuses sur les réservoirs et les flux de traceurs actuels et passés dans l'océan profond<br>The Pacific Ocean represents about 50% of the global ocean volume, making it an essential player in global biogeochemical cycles and their response to external perturbations. In particular, the deep Pacific Ocean hosts major reservoirs of carbon and nutrients, whose size and variations are largely controlled by physical tracer transports. In this thesis, we aim to better understand and constrain the transport of tracers in the deep Pacific Ocean across climate states. We use historical and new observations of conservative tracers, notably oxygen isotopes, combined with numerical models of ocean circulation. We show that isopycnal mixing is an essential control of the ventilation of Pacific mid-depths. A return of abyssal waters to the surface is identified in the modern subarctic Pacific. This upwelling pathway may have been weaker during the Last Glacial Maximum about 20,000 years ago, and the deep North Pacific may have been more strongly layered; however, evidence for the required end member changes in the south of the basin to explain this deep layering remains sparse. State-of-the-art prognostic models of global ocean circulation struggle to represent observationally inferred tracer pathways and turn-over times in the modern North Pacific. However, these tracer pathways remain insufficiently constrained and the underlying dynamics are poorly understood. Analysis of in-situ measurements of the oxygen-18 (18O) isotopic ratio of seawater provides an efficient means to better constrain the origins and routes of tracers in the deep ocean: insights on these routes are derived from existing 18O observations in the Southern, Indian, and Pacific Oceans. We suggest that additional measurements of 18O from modern ocean water samples, and from calcite shells in sediment cores, would provide valuable constraints on present-day and past tracer reservoirs and fluxes in the deep ocean
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Couespel, Damien. "La désoxygénation de l'océan au cours du 21ème siècle : influence des processus de petite et moyenne échelle." Electronic Thesis or Diss., Sorbonne université, 2018. http://www.theses.fr/2018SORUS097.
Texte intégralRésumé :
La quantité d'oxygène océanique diminue depuis 20ème siècle et, d'après les projections climatiques, cela se poursuivra sur le 21ème siècle avec des effets sur les cycles biogéochimiques, les organismes aquatiques et les écosystèmes. En subsurface, la désoxygénation est contrôlée par : 1) la solubilité déterminant la quantité d’oxygène pouvant être dissous, 2) la respiration utilisant l'oxygène pour reminéraliser la matière organique et 3) les échanges surface/subsurface. Ces mécanismes sont affectés par le changement climatique (CC) : 1) la solubilité diminue quand la température augmente, 2) la production de matière organique en surface diminue, diminuant ainsi la respiration en subsurface et 3) les échanges surface/subsurface sont ralentis en raison de l’augmentation de la stratification. La contribution relative de chacun de ces mécanismes à la désoxygénation est encore mal connue. Pour l'estimer nous avons calculé, dans une projection climatique, le transport d’oxygène à travers la base de la couche de mélange et la respiration sous la couche de mélange. Nos résultats montrent que chaque mécanisme contribue à proportion égale à la désoxygénation. Ce résultat a été obtenu avec un modèle à basse résolution. Or, des études indiquent que les processus de petite échelle peuvent influencer les mécanismes contrôlant la désoxygénation mais il n’y a pas encore d’estimation de leurs effets. Nous avons donc développé une configuration idéalisée nous permettant de réaliser des expériences de CC résolvant explicitement ces processus. Dans ce cadre, nos résultats montrent que les processus de petite échelle atténuent 1) la désoxygénation et 2) la réponse des mécanismes impliqués<br>The amount of oxygen in the ocean has decreased since the middle of the 20th century. According to climate projections, this will continue into the 21st century with effects on biogeochemical cycles, aquatic organisms and ecosystems. In the subsurface, deoxygenation is controlled by: 1) solubility, determining the amount of oxygen that can be dissolved, 2) respiration, using oxygen to remineralize organic matter and 3) surface/subsurface exchanges. These mechanisms are affected by climate change: 1) the solubility decreases as the temperature increases, 2) the production of organic matter at the surface decreases, thus decreasing the subsurface respiration and 3) the surface/subsurface exchanges are slowed down due to the increase in stratification. The relative contribution of each of these mechanisms to deoxygenation is still poorly understood. To estimate it, we calculated the transport of oxygen through the base of the mixed layer as well as the respiration under the mixed layer in a climate projection. Our results show that each mechanism contributes in equal proportion to deoxygenation. This result was obtained with a low resolution model. However, studies indicate that small-scale processes can influence the mechanisms controlling deoxygenation, but there is still no estimate of their effects. We have therefore developed an idealized configuration allowing us to perform climate change experiments that explicitly solve these processes. In this framework, our results show that small scale processes attenuate 1) deoxygenation and 2) the responses of the mechanisms involved
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Andrié, Chantal. "Utilisation des traceurs helium-3 et tritium en oceanographie." Paris 6, 1987. http://www.theses.fr/1987PA066241.
Texte intégralRésumé :
Le traceur transitoire que constitue le tritium est devenu l'un des outils les plus prometteurs dens l'etude de la circulation oceanique generale et de la capacite de l'ocean a absorber le gaz carbonique anthropogene. L'utilisation simultanee du tritium et de son descendant par voie radioactive l'helium-3 ajoute une information supplementaire: la paire de traceurs tritium et helium-3 constitue une horloge dans l'etude des masses d'eau. En plus de son origine "tritiumgenique", l'helium-3 est emis au niveau des dorsales oceaniques et il constitue un traceur de choix dans l'etude de la circulation oceanique profonde. Toutes les mesures d'helium-3 et de tritium ont ete faites par spectrometrie de masse. Protocole analytique, limite de detection et reproductibilite de la methode sont reportes dans ce travail. Sont abordes au niveau de l'interpretation des resultats: -1) les donnees d'helium-3 a la campagne merou a (ete 1982) ont permis de localiser une source active et de mettre en evidence un courant de retour intermediaire (centre vers 1000 m de profondeur), prolongement du courant profond upwelle dans la partie meridionale du bassin. -2) l'utilisation des donnees de tritium concernant la mission phycemed 1 (avril 1981) a permis de decrire la grande variabilite spatio-temporelle des processus de convection ayant lieu dans le bassin nord; le temps de renouvellement des eaux profonbdes du golfe du lion est evalue a 11 +ou- 2 ans. Les circulations profondes et de subsurface au niveau des detroits de sardaigne et de gibraltar sont precisees. -3) l'etude simultanee, suivant des niveaux isopycnaux, des donnees tritium et helium-3 de la mission topogulf (ete 1983) a permis de localiser les zones ou les processus de convection sont actifs. Une approche theorique relative a l'utilisation simultanee du tritium et de l'helium-3 est abordee. Elle utilise un modele de melange distinguant, pour une masse d'eau consideree, le temps de transit du temps de ventilation. La validite de "age tritium-helium" est testee par comparaison avec les temps de transit et de ventilation determines par le modele
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Nöjd, Mathilda, and Emma Petersson. "Parallelltak med mekanisk ventilation : En jämförelse mellan mekanisk och naturlig ventilation." Thesis, Uppsala universitet, Institutionen för samhällsbyggnad och industriell teknik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-415713.
Texte intégralRésumé :
To build and conserve the moisture proof roof constructions is a central problem in the building industry. Outdoor ventilated roof constructions is considered to be a riskful construction that can be burdened with moist damages. It is problematic to build parallel roof with low energy consumption that are resistant to moist. New demands of energy efficient buildings has contributed to an increased amount of insulation in roof constructions. Well insulated roof constructions in combinations with moist and cold winters is the main cause to the current moisture problematic in Sweden. High relative humidity in air gap and high moisture in materials increases the risk for mold growth. The winter is a critical period of time due to outside air containing high amount of moisture that can be harmful for roof constructions that are ventilated by outside air. Organic materials like wood is sustained a risk for mold growth by a relative humidity of 75%. Duration and a favorable temperature are also required for mold growth to take place. Parallel roofing usually consists of wood materials that can be attacked by mold at favorable conditions. Tongue and groove and battens have a position close to the outer layers in a parallel roofing that contributes to them being exposed to mold growth that should be especially consider. There is a large need for technical solutions to be able to handle the current moist problems in Swedish constructions. Mechanical ventilation is one of the technical solutions that is controlled by sensors that regulates the ventilations in roof constructions air gap. The mechanical ventilation is controlled by sensors and fans. Sensors measure and compares the current temperature and vapour content of the outside air and the air in the air gap. At appropriate conditions the ventilation activates and at inappropriate conditions the ventilation is limited. This report is focused on comparing outdoor ventilated parallel roofing to mechanical ventilated parallel roofing. This report studies an existing building outside Norrtälje with parallel roofing. This system is equipped with sensors that logs the temperatures, relative humidity and moisture on the tongue and groove and battens in the air gaps in both the part of the roof that is mechanically ventilated and outdoor ventilated. The collected data have been analyzed in a risk analysis and a mold analysis. The risk analysis compares data from 2 or more measuring points to be able to analyze the difference in result. The mold analysis consists of a simulation in the program: WUFI Bio and delivers an index of calculated mold growth per year. This study indicates that roof constructions with outdoor ventilation runs a big risk of mold growth during the winter season. The mechanically ventilated roof construction shows a trend that reduces the risk of mold growth in all orientations and in the ridge. The measuring points with southern orientations shows a trend that, of a mechanically ventilated roof, will reduces mold growth in a higher degree compared to the other orientations. Even though the reduced effect of mold growth in mechanically ventilated roof constructions the results indicates a result where mold growths on tongue and groove and battens. Although the risk is not as extensive as in naturally ventilated roofs.<br>Att bygga och bibehålla fuktsäkra takkonstruktioner är ett centralt problem inom byggbranschen. Utomhusventilerade takkonstruktioner anses vara en riskkonstruktion som kan drabbas av fuktskador. Det är problematiskt att bygga parallelltak med låg energiförbrukning som är beständigt mot fukt. Nya krav på energieffektiviseringar har bidragit till ökade mängder isolering i takkonstruktioner. Välisolerade takkonstruktioner i kombination med fuktiga och kalla vintrar är den huvudsakliga orsaken till den rådande fuktproblematiken som finns i Sverige. Hög relativ fuktighet i luftspalten och hög fuktkvot i materialet ökar risken för mikrobiell påväxt. Vinterhalvåret är en kritisk period eftersom utomhusluften innehåller hög mängd fukt som kan vara skadlig för takkonstruktioner som utomhusventileras. Organiska material som trävirke löper risk för mikrobiell påväxt vid en relativ fuktighet på 75 %. Det krävs även varaktighet och en gynnsam temperatur för att mikrobiell påväxt ska kunna uppstå. Parallelltak består vanligtvis av trämaterial som kan angripas av mögel vid gynnsamma förutsättningar. Råspont och läkt har en position långt ut i parallelltaket som bidrar till att de löper stor risk för mögelpåväxt och bör särskilt beaktas. Det finns stort behov av tekniska lösningar för att kunna lösa den rådande fuktproblematiken i svenska bostäder. Mekanisk ventilation är en teknisk lösning som styr och reglerar ventilationen i takkonstruktionens luftspalt. Den mekaniska ventilationen styrs av sensorer och fläktar. Sensorerna jämför temperatur och ånghalt i utomhusklimatet med klimatet i luftspalten. Vid goda klimatförhållanden tillåts ventilation i luftspalten och vid sämre förhållanden begränsas ventilationen. Syftet med den mekaniska ventilationen är att parallelltaket endast ventileras när det leder till uttorkning. Rapporten har fokus på att jämföra utomhusventilerat parallelltak (naturlig ventilation) med mekanisk ventilation. Rapporten studerar en befintlig byggnad med parallelltak belägen utanför Norrtälje. Parallelltaket är utrustat med loggrar som mäter relativ fuktighet, temperatur och fuktkvot i råspont eller läkt i luftspalter med naturlig och mekanisk ventilation. Mätdata har analyserats i en riskanalys och en mögelanalys. Riskanalysen jämför mätdata från två eller flera mätpunkter för att kunna analysera skillnader i resultatet. Mögelanalysen består av simuleringar i programmet WUFI Bio och anger ett fiktivt mögelindex för beräknad påväxt i millimeter per år. Studien indikerar att luftspalter med naturlig ventilation löper stor risk för mögelpåväxt under vinterhalvåret. Den mekaniska ventilationen uppvisar en trend som reducerar risken för mögelpåväxt i samtliga väderstreck, inklusive taknock. Mätpunkter med mekaniska ventilation orienterad mot söder och väster uppvisar en trend som procentuellt reducerar mögelpåväxten i högre grad jämfört med resterande väderstreck. Trots den reducerande effekten med mekanisk ventilation indikerar resultatet att det finns risk för mögelpåväxt även på råspont och läkt i luftspalter med mekanisk ventilation. Däremot är risken inte lika omfattande.
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Elvingson, Fredrik. "Vindar med begränsad ventilation - Fukttekniska undersökningar." Thesis, Uppsala universitet, Byggteknik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-298216.
Texte intégralRésumé :
Tougher fire requirements and the desire to make simpler designs have enabled construction companies to go from the traditional well-ventilated attic to attic with limited ventilation. Theoretically limited ventilated winds should perform well. The problem you see if there is construction moisture or external moisture sources. Problems may occur when the small ventilation is not able to remove moisture to the extent necessary. Heavier constructions usually have a large amount of construction moisture in the attic floor, which can be transferred to the attic space. Heavier structures with limited ventilated attics have not been studied previously. AK Consulting was commissioned to evaluate five attics to a construction company erected in 2014 and 2015. Former investigations showed that there was a risk initially with respect to the excess moisture from building moisture. This study was carried out with theoretical calculations on a model of an existing attic with moisture problems. The present thesis was commissioned by AK Consulting. It evaluated the data and reports from the five attics and assesses them with the help of WUFI BIO and made theoretical calculations in WUFI. The study shows that attics with limited ventilations work well initially and that the ventilation of the attic does not lead to drier attics. Longer measurement periods are required in order to see how the wind works in the long term and in different outdoor climates. It is difficult to determine the effect of initial dehumidification of the winds. The attics have little or no excess moisture over the measurement period. The recommendations are to dehumidify attics initially until further studies have been done on similar structures. It is also important to continue monitoring the attics in this study to follow up how they work in the long term and during years with different climatic conditions.
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Akhoudas, Camille. "Un nouveau regard sur la dynamique de l’océan Austral et ses interactions avec la cryosphère révélé par une approche isotopique." Electronic Thesis or Diss., Sorbonne université, 2020. http://www.theses.fr/2020SORUS464.
Texte intégralRésumé :
L’océan Austral est un acteur central de la circulation océanique mondiale et du système climatique terrestre. Malgré l’essor des observations in situ dans cette région reculée du globe depuis les années 1990 (avec notamment le début de « l’ère satellitaire » et des grands programmes internationaux d’observations tel que WOCE, CLIVAR, GO-SHIP, ou ARGO), ce vaste océan reste encore aujourd’hui largement méconnu. Il est pourtant nécessaire de parvenir à mieux observer et comprendre les mécanismes de sa dynamique océanique ainsi que sa variabilité afin de prédire au mieux l’évolution future du système climatique. Notamment, une des particularités qui rend l’océan Austral essentiel dans le système climatique est qu’il est l’un des principaux lieux de ventilation de l’océan profond, qui permet une redistribution et un stockage de chaleur, d’eau douce, de carbone, d’oxygène, et de nutriments, entre autres. Cette ventilation est en partie dirigée par une circulation verticale unique connectant la surface aux abysses océaniques, mise en mouvement par les intenses interactions et échanges de flux d’énergie et de flottabilité entre atmosphère, océan et cryosphère. Je me penche dans cette thèse sur certains aspects de la dynamique australe en m’efforçant d’apporter une vue mécanistique de la circulation grande échelle et des changements en cours. Un fil rouge méthodologique que j’emploie sur l’ensemble de cette thèse est l’utilisation d’observations des isotopes stables de l’eau, traceur passif utilisé couramment dans un grand nombre de disciplines des sciences de la terre, mais jusque récemment assez peu en océanographie physique. La mesure des isotopes de l’eau constitue un outil, qui en tant que traceurs de l’origine de l’eau, permet de mieux caractériser les différentes composantes du cycle hydrologique ainsi que son évolution. En particulier, la composition isotopique de l’eau de mer représente une empreinte importante des masses d’eau, contenant des informations sur les conditions de leur formation et leur évolution. Dans cette thèse, au-delà du travail méthodologique important sur le terrain et en laboratoire pour l’échantillonnage, l’analyse et la calibration des mesures isotopiques, j’utilise les isotopes de l’eau en combinaison avec d’autres traceurs plus conventionnels pour aborder avec un nouveau regard, les questions du rôle des interactions entre océan et calotte polaire à la circulation grande échelle, de la signature des eaux de surface dans les abysses, ou encore de l’impact des changements de régimes atmosphériques ou de fonte de la cryosphère sur l’océan de surface. Au-delà de la seule utilisation des isotopes stables de l’eau, les approches que j’ai mises en place m’ont permis de documenter la quantité de fonte et de regel d’une des plus grandes cavités glaciaires au monde, qui influence les caractéristiques des masses d’eau denses, précurseurs des eaux abyssales se formant en mer de Weddell. Mes résultats mettent également à jour la proportion que représente, in fine, ces eaux denses dans la production des eaux abyssales dans le secteur Atlantique de l’océan Austral. Je détaille les processus qui mènent à la formation des eaux abyssales et avec cette nouvelle force, je montre que des estimations passées de la production d’eaux abyssales en apparente contradiction, s’attaquaient en réalité à différents processus. Finalement, je quantifie les changements des apports en eau douce lors des trois dernières décennies sur les tendances des propriétés de surface dans le secteur Indien de l’océan Austral. Mes résultats démontrent que des changements dans le régime des précipitations expliquent les changements des caractéristiques de l’océan surface affectant la stratification avec des conséquences sur la formation des masses d’eau et la circulation de retournement de l’océan Austral à grande échelle<br>The Southern Ocean is a key component in global ocean circulation and the Earth's climate system. Despite the increase of in situ observations in this remote region since the 1990s (notably with the « satellite era » and major international observation programs such as WOCE, CLIVAR, GO-SHIP, or ARGO), this immense ocean remains largely unknown. However, it is essential to observe and understand the mechanisms of its dynamics as well as its variability with the aim to predict the future evolution of the climate system. In particular, one important characteristic of the Southern Ocean is that it is one of the main sites of deep ocean ventilation, which allows redistribution and sequestration of heat, freshwater, carbon, oxygen, and nutrients. This ventilation process is mainly associated with a vertical circulation connecting the ocean surface to the abyss, fueled by intense interactions and exchanges of energy and buoyancy fluxes between atmosphere, ocean and cryosphere. In this thesis, I apprehend some aspects of the Southern Ocean dynamics by providing a mechanistic view of large-scale circulation and its ongoing changes. The approach I use throughout this thesis is based on observations of stable water isotopes, a passive tracer commonly used in a large number of earth science disciplines, but until recently only sparsely used in physical oceanography. Stable water isotopes constitute a robust tool which, as a tracer of the origin of water, help to better characterize the different components of the hydrological cycle as well as its evolution. In particular, the isotopic composition of seawater represents an important imprint of water masses, containing information on the conditions of their formation and their evolution. In this thesis, beyond the important methodological work at sea and in the laboratory for the sampling, analysis and calibration of isotopic measurements, I use the stable water isotopes in combination with other more conventional tracers to apprehend, with a new perspective, the questions of the role of interactions between the Southern Ocean and the Antarctic Ice Sheet in large-scale circulation, the signature of surface waters in the abyss, or even the impact of changes in atmospheric or cryosphere regimes on the surface ocean. Beyond the only use of stable water isotopes, original approaches have allowed me to document melting and refreezing of one of the largest ice shelves in the world, which influences the characteristics of the dense waters, precursors of abyssal waters produced in the Weddell Sea. My results also reveal the proportion of these dense waters in bottom water formation in the Atlantic sector of the Southern Ocean. We detail the processes that lead to the formation of bottom waters and with this new insight, we demonstrate that past estimates of bottom water production, in apparent contradiction, were actually focusing on different processes. Finally, I propose to quantify the changes in freshwater inputs over the past three decades that influence the trends in surface properties in the Indian sector of the Southern Ocean. The results demonstrate that changes in the precipitation regime explain changes in the surface ocean characteristics impacting stratification with consequences for large-scale water mass formation and overturning circulation in the Southern Ocean
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Jonsson, Reine. "Energieffektivisering i flerbostadshus : Undersökning av lönsamheten med energieffektivare ventilation." Thesis, Mälardalen University, School of Sustainable Development of Society and Technology, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-7441.
Texte intégralRésumé :
<p>This thesis is based on a case study for the real estate manager Mimer in Västerås. Mimer provides a great deal of this city’s rental apartments. Many of their buildings have ventilation systems with a type of heat-recovery called “heatpipe”. This case study focuses on two buildings which have certain problems with these heatpipes. The recovery rates of the existing systems are low, and one building suffers from a warm indoor climate in the summertime. Problems with the indoor climate seem to stem from a faulty installation of the heatpipe. This building does also have considerably higher energy consumption than the other one, which leads suspicions to overloaded fan motors.</p><p> </p><p>The main purpose of this study is to retrieve information about the present situation energy- and ecomonywise. A new type of heat recovery and new fans has been chosen by Mimer in order to calculate expected new energy consumption for these buildings. These values will lead to a few LCC calculations which show life cycle costs for the existing systems and the new systems. Based on the LCC calculations one or more options will be chosen as a recommended action for the ventilation systems. The recommendations will be analysed and discussed from different point of views that are relevant for a real estate manager.</p>
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Blomqvist, Sofia, and Dennis Sundby. "Energianalys av fastighet Brynäs 12:1 : Energikartläggning med effektiviseringsåtgärder inriktning mot ventilation." Thesis, Högskolan i Gävle, Avdelningen för bygg- energi- och miljöteknik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-17140.
Texte intégralRésumé :
Energianvändningen i Sverige och världen förväntas öka och bostads- och servicesektorn står för 40 % av världens totala energibehov. Det är viktigt att energieffektivisera redan befintliga byggnader och optimera dess system då en lägre energianvändning gynnar både miljön och ekonomin. En byggnads ventilationssystem står för en stor del av en fastighets energianvändning och det finns ofta stor potential för systemet att optimeras och effektiviseras. En fastighetsägare vill inte ha fastigheter som står outhyrda. Outhyrda lokaler betyder minskade intäkter i hyror och i vissa fall tillkommer energianvändning för de tomma lokalerna i form av uppvärmning och ventilation som fastighetsägaren måste betala. System som helt kan stängas av eller styras beroende på ventilationsbehov behövs för att den sistnämnda kostnaden ska reduceras helt under tiden lokalen är outhyrd och för att den totala energianvändningen ska minska när en hyresgäst flyttar in. Ventilationens syfte är att ventilera bort fukt, värme, partiklar och koldioxid så att ett bra inomhusklimat skapas för de personer som vistas i byggnaden. Den vanligaste ventilationsprincipen för offentliga byggnader är att ventilera luft med ett konstant luftflöde genom ett constant air volume-system. Med behovsanpassad ventilation i form av ett variable air volume-system kan stora besparingar göras då man anpassar luftflödet efter det verkliga ventilationsbehovet istället för att ventilera byggnaden med ett konstant maxflöde. En installation av ett VAV-system i form av CO2- eller närvarostyrning sänker ventilationens energianvändning samtidigt som kvaliteten på inomhusmiljön bibehålls. Arbetet som har utförts innefattar en energikartläggning av fastigheten Brynäs 12:1 då en energikartläggning hjälper till att förstå en byggnads energianvändning och identifierar möjliga energisparåtgärder. Energianvändningen för fastighetens delsystem har kartlagts och analyserats för att ta fram förslag på besparingsåtgärder. Resultatet av energikartläggningen visade att det fanns stor besparingspotential för ventilationsaggregat TA1, TA2 och TA3:s el- och värmeanvändning. Om de åtgärder rörande ventilationen som presenteras i arbetet som till exempel flödes- och tidsreducering vidtas kan en energibesparing på 333 MWh/år uppnås, vilket är 28 % av fastighetens totala årliga energianvändning.<br>Energy use in Sweden and the world is expected to increase and the residential and services account for 40% of total world energy demand. It is important that the energy efficiency of existing buildings and optimizing its systems as a lower energy benefits both the environment and the economy. A building's ventilation system account for a large proportion of a property's energy use, and there is often great potential for the system to be optimized and streamlined. A property owner does not want properties that are vacant. Vacant premises mean less income in rent and in some cases there will be increased energy costs for the empty space in form of heating and ventilation, for the property owner to pay. Systems that can completely shut off or controlled depending on ventilation requirements needed for the latter cost will be reduced completely when the premises are vacant and that the total energy will decrease when a tenant moves out. Ventilating purpose is to divert moisture, heat, particulates and carbon dioxide so that a good indoor climate is created for the people staying in the building. The most common ventilation principle for public buildings is to vent air with a constant air flow through a CAV system. With demand-based ventilation in the form of a VAV system, huge savings can be made when one adjusts airflow to the actual ventilation requirement instead of ventilating the building with a constant maximum flow. An installation of a VAV system in the form of CO2 or presence control, reduces ventilation energy consumption, while the quality of the indoor environment is maintained. The work that has been carried out includes an energy survey of the property Brynäs 12:1 as an energy survey helps to understand a building's energy use, and identifies potential energy savings. The energy use for the building subsystems have been identified and analyzed in order to develop proposals for cost cutting measures. The results of the energy audit revealed that there was great potential for savings for ventilation units TA1, TA2 and TA3's electricity and heat use. If the measures for ventilation as presented in the work, such as flow and time reduction is taken, an energy saving of 333 MWh/year is achieved, which is 28% of the property's total annual energy consumption.
Livres sur le sujet "Ventilation – Mer"
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Kreit, John W., and John A. Kellum. Mechanical Ventilation. Oxford University Press, 2017. http://dx.doi.org/10.1093/med/9780190670085.001.0001.
Texte intégralRésumé :
Mechanical Ventilation—Physiology and Practice provides a comprehensive review of the physiological principles underlying mechanical ventilation, as well as practical approaches to the management of patients with respiratory failure. The book explains instrumentation and terminology, ventilator modes and breath types, ventilator alarms, how to write ventilator orders, and how to diagnose and correct patient–ventilator asynchrony. It also discusses the physiological assessment of the mechanically ventilated patient and the diagnosis and management of dynamic hyperinflation, and describes how to manage patients with the acute respiratory distress syndrome (ARDS), severe obstructive lung disease, and right ventricular failure; how to “wean” patients from the ventilator; and how and when to use noninvasive ventilation.
3
Lei, Yuan. Introduction. Oxford University Press, 2017. http://dx.doi.org/10.1093/med/9780198784975.003.0001.
Texte intégralRésumé :
The ‘Introduction’ chapter presents the concept of the entire ventilator system, whose understanding is crucial for the clinician performing mechanical ventilation. Mechanical ventilation is a risky, expensive, and error-prone therapy, the author asserts, which is why it is so important to understand not just the clinical application of ventilation, but also the equipment used in ventilation therapy. Furthermore, the ventilator must be viewed within the context of the larger ventilation system. This chapter defines the book’s audiences and discusses its value to them.
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Oliver, Charles M., and S. Ramani Moonesinghe. Setting rate, volume, and time in ventilatory support. Oxford University Press, 2016. http://dx.doi.org/10.1093/med/9780199600830.003.0093.
Texte intégralRésumé :
Ventilator rate, volume, and time parameters are interrelated directly, mechanically, and physiologically, and interactions between intrinsic pulmonary physio-mechanics, pathology and the effects of mechanical ventilation complex. The physiological consequences of mechanical ventilation and risks of ventilator-induced trauma may be exacerbated by lung pathology. Programming of ventilator parameters should be considered within the context of an individualized ventilatory strategy to achieve adequate gas exchange, while minimizing attendant risks of mechanical ventilation. Recommended strategies should be modified within accepted limits to mitigate disease-specific risks. Parameters should subsequently be titrated against blood gas- and ventilator-derived targets, and other clinical variables.
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Fanelli, Vito, and V. Marco Ranieri. Failure to ventilate in critical illness. Oxford University Press, 2016. http://dx.doi.org/10.1093/med/9780199600830.003.0100.
Texte intégralRésumé :
Mechanical ventilation is an efficacious therapy to respiratory failure because it improves gas exchange and rests respiratory muscles. During controlled mechanical ventilation, a patient’s inspiratory muscles are resting and the ventilator delivers a preset tidal volume through the generation of inspiratory flow, overcoming resistive and elastic thresholds of the respiratory system. During assisted ventilation, the same goal is reached through an interplay between the patient’s inspiratory muscles and ventilator. Every perturbation of this interaction causes patient ventilator asynchrony and exposes to the risk of failure to ventilate. Patient–ventilator asynchrony may occur at each stage of assisted breath Signs of patient’s discomfort, the use of accessory muscles, tachycardia, hypertension, and assessment of flow and airway pressure traces displayed on modern ventilators, helps to detect asynchronies. Prompt recognition and intervention to improve patient–ventilator interaction may expedite liberation from mechanical ventilation, and reduce intensive care unit and length of hospital stay.
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Lei, Yuan. Medical Ventilator System Basics: A clinical guide. Oxford University Press, 2017. http://dx.doi.org/10.1093/med/9780198784975.001.0001.
Texte intégralRésumé :
Medical Ventilator System Basics: A clinical guide—unlike books that focus on clinical applications, or that provide specifics about individual ventilator models, this is a practical guide about the equipment used for positive pressure mechanical ventilation. This book provides the information a clinician needs every day: how to assemble a ventilator system, how to determine appropriate ventilator settings, how to make sense of monitored data, how to respond to alarms, and how to troubleshoot ventilation problems. The book applies to all ventilators based on the intermittent positive pressure ventilation (IPPV) operating principle. In a systematic and comprehensive way, the book steps the user through the ventilator system, starting with its pneumatic principles to an explanation of the anatomy and physiology of respiration. It describes the system components, including the ventilator, breathing circuit, humidifier, and nebulizer. The book then introduces ventilation modes, starting with an explanation of the building blocks of breath variables and breath types. It describes the major ventilator functions, including control parameters, monitoring, and alarms. Along the way the book provides much practical troubleshooting information. Clearly written and generously illustrated, the book is a handy reference for anyone involved with mechanical ventilation, clinicians and non-clinicians alike. It is suitable as a teaching aid for respiratory therapy education and as a practical handbook in clinical practice.
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Waldmann, Carl, Neil Soni, and Andrew Rhodes. Respiratory therapy techniques. Oxford University Press, 2011. http://dx.doi.org/10.1093/med/9780199229581.003.0001.
Texte intégralRésumé :
Oxygen therapy 2Ventilatory support: indications 6IPPV—description of ventilators 8IPPV—modes of ventilation 10IPPV—adjusting the ventilator 12IPPV—barotrauma 14IPPV—weaning techniques 16High-frequency ventilation 18Positive end-respiratory pressure 22Continuous positive airway pressure ventilation (CPAP) 24Recruitment manoeuvres 26Prone position ventilation 28...
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Kreit, John W. Ventilator Modes and Breath Types. Edited by John W. Kreit. Oxford University Press, 2017. http://dx.doi.org/10.1093/med/9780190670085.003.0005.
Texte intégralRésumé :
Ventilator Modes and Breath Types describes, compares, and contrasts the different modes and breath types that are available on intensive care unit ventilators. The chapter first covers the various ventilator modes: continuous mandatory ventilation, synchronized intermittent mandatory ventilation, spontaneous ventilation, and bi-level ventilation. Then it turns to a discussion of the various mechanical breath types: volume control, pressure control, adaptive pressure control, pressure support, and finally, adaptive pressure support. It also provides practical advice about how and when to use each mode–breath type combination. Eight Boxes in the chapter discuss each breath type, and list each type’s features, and its clinician-set parameters.
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Masip, Josep, Kenneth Planas, and Arantxa Mas. Non-invasive ventilation. Oxford University Press, 2015. http://dx.doi.org/10.1093/med/9780199687039.003.0025.
Texte intégralRésumé :
During the last 25 years, the use of non-invasive ventilation has grown substantially. Non-invasive ventilation refers to the delivery of positive pressure to the lungs without endotracheal intubation and plays a significant role in the treatment of patients with acute respiratory failure and in the domiciliary management of some chronic respiratory and sleep disorders. In the intensive and acute care setting, the primary aim of non-invasive ventilation is to avoid intubation, and it is mainly used in patients with chronic obstructive pulmonary disease exacerbations, acute cardiogenic pulmonary oedema, or in the context of weaning, situations in which a reduction in mortality has been demonstrated. The principal techniques are continuous positive airway pressure and bilevel pressure support ventilation. Whereas non-invasive pressure support ventilation requires a ventilator, continuous positive airway pressure is a simpler technique that can be easily used in non-equipped areas such as the pre-hospital setting. The success of non-invasive ventilation is related to the adequate timing and selection of patients, as well as the appropriate use of interfaces, the synchrony of patient-ventilator, and the fine-tuning of the ventilator.
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Masip, Josep, Kenneth Planas, and Arantxa Mas. Non-invasive ventilation. Oxford University Press, 2016. http://dx.doi.org/10.1093/med/9780199687039.003.0025_update_001.
Texte intégralRésumé :
During the last 25 years, the use of non-invasive ventilation has grown substantially. Non-invasive ventilation refers to the delivery of positive pressure to the lungs without endotracheal intubation and plays a significant role in the treatment of patients with acute respiratory failure and in the domiciliary management of some chronic respiratory and sleep disorders. In the intensive and acute care setting, the primary aim of non-invasive ventilation is to avoid intubation, and it is mainly used in patients with chronic obstructive pulmonary disease exacerbations, acute cardiogenic pulmonary oedema, or in the context of weaning, situations in which a reduction in mortality has been demonstrated. The principal techniques are continuous positive airway pressure and bilevel pressure support ventilation. Whereas non-invasive pressure support ventilation requires a ventilator, continuous positive airway pressure is a simpler technique that can be easily used in non-equipped areas such as the pre-hospital setting. The success of non-invasive ventilation is related to the adequate timing and selection of patients, as well as the appropriate use of interfaces, the synchrony of patient-ventilator, and the fine-tuning of the ventilator.
Chapitres de livres sur le sujet "Ventilation – Mer"
1
Samandouras, George. "The ventilated patient." In The Neurosurgeon's Handbook. Oxford University Press, 2010. http://dx.doi.org/10.1093/med/9780198570677.003.0108.
Texte intégralRésumé :
Chapter 3.4, The Ventilated Patient, covers clinical respiratory physiology, oxygen therapy, abnormal respiratory patterns, mechanical ventilation, ventilators, ventilator settings, setting up a ventilator, complications of ventilation, and ventilator weaning.
2
Mahboobi, Sohail K., and Mahad Sohail. "Complications and Side Effects of Mechanical Ventilation." In Advanced Anesthesia Review, edited by Alaa Abd-Elsayed. Oxford University PressNew York, 2023. http://dx.doi.org/10.1093/med/9780197584521.003.0108.
Texte intégralRésumé :
Abstract Mechanical ventilation is routinely used not only in critical care units but also on regular floors. Caring for a patient on a ventilator requires knowledge and understanding of the ventilator, its functioning, indications for placing a patient on the ventilator, choice of optimum ventilator mode, and sedation. In spite of the life-saving nature of mechanical ventilation, it is not free of complications and side effects. In fact, prolonged mechanical ventilation affects almost every organ system of the body, including the cardiorespiratory, gastrointestinal, renal, brain, hematologic, and immune systems. Successful outcome depends on prevention of possible complications, and adequate knowledge and planning are required to achieve this goal. This chapter summarizes the complications related to mechanical ventilation systematically.
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Fozard, Jessica, and Krystle Shafer. "Intubated and boarded in the ED: Ventilator 101." In Critical Care Emergencies, edited by Lillian Liang Emlet. Oxford University PressNew York, 2023. http://dx.doi.org/10.1093/med/9780190082581.003.0008.
Texte intégralRésumé :
Abstract Emergency physicians can be empowered by knowing the basics of how to safely ventilate patients with the mechanical ventilator. Learning how to initiate mechanical ventilation with appropriate settings is an important skill to learn, as inappropriate settings can increase length of stay, lengthen time on the ventilator, and negatively impact mortality. After choosing the mode of ventilator (the authors recommend volume-control mode), the four settings that must be set are respiratory rate, tidal volume, positive end-expiratory pressure, and fraction of inspired oxygen. A lung-protective ventilation strategy should be used for all patients. Additional parameters are titrated based on the patient’s comorbidities and indication for mechanical ventilation.
4
Boesing, Christoph, Thomas Luecke, and Joerg Krebs. "Mechanical Ventilation: How to Set Up the Ventilator." In Oxford Textbook of Respiratory Critical Care. Oxford University PressOxford, 2023. http://dx.doi.org/10.1093/med/9780198766438.003.0011.
Texte intégralRésumé :
Abstract Summary Mechanical ventilation is a key component in the management of critically ill patients. Therefore, the attending physician needs a comprehensive understanding of the indications, aims, and underlying physiology when treating mechanically ventilated patients to avoid potentially detrimental consequences like ventilator-induced lung injury. A structured approach includes an assessment of the respiratory system, the clinical situation of the patient, and choosing the correct ventilatory mode that avoids patient–ventilator asynchrony. This chapter outlines essential features of respiratory mechanics, their effect on different ventilator strategies, and key components of mechanical ventilation.
5
Waldmann, Carl, Andrew Rhodes, Neil Soni, and Jonathan Handy. "Respiratory therapy techniques." In Oxford Desk Reference: Critical Care. Oxford University Press, 2019. http://dx.doi.org/10.1093/med/9780198723561.003.0001.
Texte intégralRésumé :
This chapter discusses respiratory therapy techniques and includes discussion on oxygen therapy, discussion of intermittent positive pressure ventilation and description of ventilators, modes of ventilation, adjusting the ventilator, barotrauma, and weaning techniques. The chapter also discusses high-frequency ventilation, airway pressure release ventilation, as well as positive end-respiratory pressure, continuous positive airway pressure ventilation, recruitment manoeuvres, prone position ventilation, non-invasive positive pressure ventilation, extracorporeal membrane oxygenation, cricothyroidotomy, tracheostomy, aftercare of the patient with a tracheostomy, chest drain insertion, pleural aspiration, flexible bronchoscopy, chest physiotherapy, humidification, and heart–lung interactions.
6
Formenti, Paolo, and John J. Marini. "Monitoring Lung-protective Ventilation." In Oxford Textbook of Respiratory Critical Care. Oxford University PressOxford, 2023. http://dx.doi.org/10.1093/med/9780198766438.003.0015.
Texte intégralRésumé :
Abstract Summary Lung-protective ventilation strategies have been developed to reduce ventilator-associated lung tissue injury and simultaneously improve systemic oxygenation. We now know that mechanical ventilation per se can aggravate lung injury, a process referred to as ‘ventilator-induced lung injury’ (VILI), through several mechanisms, including volutrauma, barotrauma, and biotrauma. Lung-protective ventilation regulates positive end-expiratory pressure (PEEP), maintains a greater number of pulmonary alveoli in an open state, and avoids excessive end-expiratory lung volume and mechanical power while maintaining an adequate tidal volume and minute ventilation. Moreover, in preventing the collapse of open pulmonary alveoli, PEEP not only helps maintain production and function of pulmonary surfactants but also reduces the shear stress. Current research suggests that reduction of ventilator-associated lung injury or VILI is a main avenue for further reducing mortality in this syndrome. In this chapter, we offer a review of the current literature regarding the use of transpulmonary pressure (Ptp), driving pressure, mechanical power, and stress index in reducing the risk of VILI.
7
Kritek, Patricia A. "Mechanical Ventilation." In The Brigham Intensive Review of Internal Medicine. Oxford University Press, 2014. http://dx.doi.org/10.1093/med/9780199358274.003.0038.
Texte intégralRésumé :
Patients receive mechanical ventilation for a variety of reasons. The general practitioner should understand the broad categories for initiation of mechanical ventilation as well as be able to determine when a patient can be liberated from a ventilator. The majority of this chapter focuses on the common modes of ventilation, the difference between pressure- and volume-cycled breath delivery and how these different modes are monitored.
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Gregoretti, Cesare, Andrea Cortegiani, Vincenzo Russotto, and Lara Pisani. "Non-invasive Ventilation in Critical Care." In Oxford Textbook of Respiratory Critical Care. Oxford University PressOxford, 2023. http://dx.doi.org/10.1093/med/9780198766438.003.0008.
Texte intégralRésumé :
Abstract Summary Acute respiratory failure (ARF) is characterized by impaired gas exchange and increased work of breathing, secondary to an acute lung and/or respiratory pump failure. Ventilatory assistance to respiratory function can be applied either invasively through an endotracheal tube or by means of external interfaces, such as masks, mouthpieces, prongs, and helmets, referred to as non-invasive ventilation (NIV). Acute NIV needs to be provided in an appropriately skilled and equipped environment, with ready access to advanced respiratory therapies, including invasive mechanical ventilation. Effective use of NIV requires understanding of the ventilator system and interfaces. Key ventilator features include the nature of gas delivery (high-pressure or turbine-driven), the variables used for setting gas delivery, and the timing of breaths and the circuits. Ventilators can deliver either non-invasive continuous positive airway pressure (CPAP) or vary the positive pressure, at different levels (nPPV) to facilitate ventilation. A wide variety of interfaces are available, although those commonly used for acute NIV include orofacial masks, total face masks, and helmets. The type of ventilator, the settings on that ventilator, and the interface all need to be individualized to the patient dependent on their underlying pathology, physiological features, and capacity to tolerate NIV, and a careful approach to patient optimization is critical to successful use of NIV.
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Murphy, Patrick B., Andrew Jones, and Luigi Camporota. "Liberation from Mechanical Ventilation." In Oxford Textbook of Respiratory Critical Care. Oxford University PressOxford, 2023. http://dx.doi.org/10.1093/med/9780198766438.003.0064.
Texte intégralRésumé :
Abstract Summary Prolonged mechanical ventilation accounts for an important number of intensive care unit bed days. Weaning is the process of moving towards liberation from mechanical ventilation following resolution of the acute physiological insult that resulted in intensive care admission. Weaning is not simply the reduction of ventilator pressure support but is the global process of progressing a ventilator-dependent patient to return to spontaneous breathing and subsequent extubation or decannulation from tracheostomy. While readiness testing and simple weaning can be protocol driven, patients who progress from difficult weaning to prolonged mechanical ventilation will often require detailed physiological assessment in order to identify the reason for weaning failure. Complex weaning involves not just attention to the respiratory physiological impairment but a multi-disciplinary approach involving physical rehabilitation and psychological support to tackle the invariably present co-morbidities that will halt weaning. This appears to be most cost-effectively delivered in specialist centres.
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Eberhardt, Christiane S., and Peter C. Rimensberger. "Paediatric acute respiratory distress syndrome." In Challenging Concepts in Paediatric Critical Care. Oxford University Press, 2020. http://dx.doi.org/10.1093/med/9780198794592.003.0006.
Texte intégralRésumé :
Acute respiratory distress syndrome (ARDS) is an important condition associated with significant morbidity and mortality in both adults and children. Chapter 6 begins by explaining the definition of paediatric ARDS (PARDS), its severity stratification, risk factors for its development, and its pathophysiology. The evidence base for lung-protective ventilation strategies is covered, with recommended goals given permissive hypoxaemia and hypercapnia. Different modes of ventilation for ARDS are examined: non-invasive ventilation, conventional mechanical ventilation, high-frequency oscillatory ventilation, and neutrally-adjusted ventilator assist, and the relative merits of pressure and volume limitation for lung protection in adults and children. Adjuvant therapies for PARDS are explored: fluid restriction; neuromuscular blocking agents; prone positioning; steroids; inhaled nitric oxide; and surfactant therapy. The chapter concludes by addressing the challenges that remain in defining and managing ARDS, and suggests how patients should be followed up following discharge.
Actes de conférences sur le sujet "Ventilation – Mer"
1
Walter, Marian, and Steffen Leonhardt. "Control applications in artificial ventilation." In 2007 Mediterranean Conference on Control & Automation. IEEE, 2007. http://dx.doi.org/10.1109/med.2007.4433762.
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Chynkiamis, Nikolaos, Matthew Armstrong, James Manifield, et al. "Hemodynamic effects of portable non-invasive ventilation in healthy men." In ERS International Congress 2019 abstracts. European Respiratory Society, 2019. http://dx.doi.org/10.1183/13993003.congress-2019.pa757.
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Pomprapa, Anake, Philipp A. Pickerodt, Wolfgang Braun, et al. "Automatic artificial ventilation therapy using the ARDSNet protocol enforcing dynamical constraints." In 2017 25th Mediterranean Conference on Control and Automation (MED). IEEE, 2017. http://dx.doi.org/10.1109/med.2017.7984124.
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Jime´nez, M. J., J. D. Guzma´n, M. R. Heras, J. Arce, J. P. Xama´n, and G. Alvarez. "Thermal Performance of a Natural Ventilation System." In ASME 2010 4th International Conference on Energy Sustainability. ASMEDC, 2010. http://dx.doi.org/10.1115/es2010-90264.
Texte intégralRésumé :
Natural ventilation in buildings using solar passive systems, such as solar chimneys, has emerged in the last years. Several theoretical and experimental studies in the literature show that their design parameters strongly depend on the ambient conditions, in which they are installed. In order to increase the knowledge of this kind of systems, this work presents the thermal behavior of a stand alone experimental solar chimney during one year. The dimensions of the solar chimney are 5.60 m high, 1.0 m width, and 0.52 m depth. The absorber plate is made of a common reinforced concrete wall of 4.5 m high, 1.0 m wide and 0.15 m depth. This system was designed by Marti´ J., and Heras M.R. in 2003 [1,2] and it is located in the Laboratorio de Ensayos Energe´ticos para Componentes de la Edificacio´n (LECE) in the Plataforma Solar of Almeri´a (PSA) in Spain. The entrance of this solar chimney was redesigned in 2007 by Arce et al. [3] and also the instrumentation of the system was increased and improved. During one year, the solar chimney was monitored and several experimental variables were measured. The results present the temperature profiles of the different measured elements of the solar chimney as well as the air mass flow rate through the solar chimney channel. It was observed that the effect of the outdoor wind added to the thermal effects plays an important role affecting the performance of the solar chimney studied.
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Na, Xue, Lin Hongtao, Liu Xinjian, Mao Yawei, and Qiu Lin. "Impact of Switching Time Interval for Dual Intakes on Workers in Main Control Room During Accidents." In 2017 25th International Conference on Nuclear Engineering. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/icone25-67742.
Texte intégralRésumé :
The main control room (MCR) ventilation system has been designed to maintain habitability of the control room envelope both under normal condition and accident condition. The system adopting dual air intakes adds one more air intake for accidents at suitable position. During accidents, the air intake with lower contamination will be selected and the other with higher contamination will be isolated, to reduce the amount of radioactive substances entering MCR extremely and enhance the habitability of MCR envelop. This paper is devoted to research on the impact of switching time interval (STI) for dual intakes on workers in main control room during accidents. As the contamination condition varies, the switching action will be happened. Switching time interval (STI) referred in this paper means the time between two switching actions. When accidents occur, the air intake will operate and switch between two intakes automatically. The action of switching will be influenced by several parameters: the meteorological conditions of the site, the response features of the monitoring instruments and the source term released to the environment after accidents. Analysis of these parameters and their sensitivity analysis are performed, which show that the ventilation system cannot afford too frequent switching actions resulted from instantaneous sudden changes of intake’s activity. That’s the reason why it is necessary to set a minimum STI which means the contamination of one intake have to be lower than the other intake and this dominant position should be kept longer than the minimum STI, if not, the switching action will not be happened. As it is essential to set a minimum STI to prevent frequent switching of system, the analysis of its impact on the atmospheric relative concentrations and the doses of the workers in main control room are performed on basis of specific site meteorological condition and the response characteristic of dose monitoring instruments. Three kinds of accident release conditions are considered, which are relief valve release, containment leakage and elevated funnel release. The atmospheric relative concentrations and the doses of the workers in MCR are evaluated for every case and compared with the dose limits. Finally an acceptable minimum STI of dual air intakes is recommended.
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Sobotka, Lukas, Roman Pechanek, Martin Skalicky, and Lukas Veg. "Thermal and Ventilation Analysis of PMSG with a Radial External Fan." In 2022 20th International Conference on Mechatronics - Mechatronika (ME). IEEE, 2022. http://dx.doi.org/10.1109/me54704.2022.9983184.
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Yu, Xin, Yuqing Lin, and Yan Zhang. "Performance Analysis of Eductor Used for Main Control Room Ventilating in Nuclear Power Plant." In 2017 25th International Conference on Nuclear Engineering. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/icone25-66220.
Texte intégralRésumé :
This paper proposes the experimental research for the performance of the air eductor used in main control room (MCR). The air eductor is used for emergency ventilating in advanced passive pressurized water reactor in accident. The compress air is supplied to the eductor as a power source and the indoor air is suctioned to the eductor. The performance of the eductor is related to the habitability of MCR. The entrainment ratio and the air pressure of discharge side are the main concerned performance. The entrainment ratio is a value that resulted from the compress air flow rate divided by the suction air flow rate. A test system was set up to test the performance of eductor. The experimental results show that the entrainment ratio of rectangle nozzle with compress air pressure 0.76MPa, 0.80MPa and 0.83MPa were 15.02, 15.04 and 15.06, respectively.
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Jin, Sike, Jiali Jin, and Yanfeng Gong. "Natural ventilation without air breathing in the top openings of highway tunnels." In MATERIALS SCIENCE, ENERGY TECHNOLOGY, AND POWER ENGINEERING I: 1st International Conference on Materials Science, Energy Technology, Power Engineering (MEP 2017). Author(s), 2017. http://dx.doi.org/10.1063/1.4982486.
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Stefanov, Lachezar, Svilen Neykov, and Lubomir Mladenov. "CORRELATION BETWEEN CONTROL TEST TIMES RELATED TO THE ANAEROBIC THRESHOLD DETERMINED BY THE X-METHOD IN ROWERS." In INTERNATIONAL SCIENTIFIC CONGRESS “APPLIED SPORTS SCIENCES”. Scientific Publishing House NSA Press, 2022. http://dx.doi.org/10.37393/icass2022/47.
Texte intégralRésumé :
ABSTRACT Aim: The aim of the study is to investigate the correlation between the times for overcoming the distance of 2000 m achieved in control tests on the water and the anaerobic threshold determined by the X-method in laboratory conditions. Material and Methods: Includes collection and analysis of the times achieved in overcoming the distance of 2000 m and the anaerobic threshold determined by the X-method, related to the individual ergometric power and heart rate for each participant. Five elite rowers from the National Team of Bulgaria, men, for the period from 2018 to 2021 were examined. To determine the anaerobic threshold by the X-method, we used the data from minute pulmonary ventilation and heart rate recorded every 20 s during the maximum spiroergometric test with increasing intensity. The test was performed on a Concept II rowing machine and equipment measuring pulmonary ventilation and heart rate. Results: The Pearson coefficient r = .457 ( = .05) shows a moderate correlation between the times for overcoming the distance of 2000 m, and the heart rate recorded at the anaerobic threshold determined by the X-method. Conclusion: The X-method for determining the anaerobic threshold is an relevant method in the control of the training process and has prognostic value in determining the functional status of rowers. An advantage is the significantly lower cost of the used diagnostic equipment compared to the cost of a conventional gas analyzer.
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Garza, Gladys, Peiwen Li, and Douglas Loy. "Micro-Fluidic Assisted Passive Direct Methanol Fuel Cells." In ASME 2012 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/imece2012-88540.
Texte intégralRésumé :
A novel design of micro-fluidic structure has been proposed to facilitate passive methanol supply and ventilation of carbon dioxide in direct methanol fuel cells (DMFC). Experimental study was conducted for three in-house fabricated cells which have different membrane-electrode-assemblies (MEA) and cathode-side air-breathing current collectors. Low rate of passive methanol supply and control was accomplished through capillary-force-driven mass transfer in the in-plane of carbon paper wicks. The low methanol supply rate using this passive method only meets the need of fuel of the electrochemical reaction, and there is almost no surplus methanol that could cross over the membrane. The micro-fluidic structure on the anode plate also makes passive removal of the CO2 gas from the electrochemical reaction. The influence of the concentration of methanol and cell operation temperature was examined and compared in the study. The results reveal very promising performance in the passive DMFCs when a methanol concentration is above 8M.
Rapports d'organisations sur le sujet "Ventilation – Mer"
1
R.J. Garrett. CLASSIFICATION OF THE MGR SUBSURFACE VENTILATION SYSTEM. Office of Scientific and Technical Information (OSTI), 1999. http://dx.doi.org/10.2172/860245.
Texte intégral
2
S.E. Salzman. CLASSIFICATION OF THE MGR WASTE TREATMENT BUILDING VENTILATION SYSTEM. Office of Scientific and Technical Information (OSTI), 1999. http://dx.doi.org/10.2172/860260.
Texte intégral
3
J.A. Ziegler. CLASSIFICATION OF THE MGR WASTE HANDLING BUILDING VENTILATION SYSTEM. Office of Scientific and Technical Information (OSTI), 2000. http://dx.doi.org/10.2172/861101.
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Vanthoor, B. H. E., and I. Tsafaras. Vergelijking tomatenteelten met een Ventilation Jet systeem : als onderdeel van het monitoringsproject. Wageningen University & Research, BU Glastuinbouw, 2018. http://dx.doi.org/10.18174/440767.
Texte intégral
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D. A. Padula. RADIATION ACCESS ZONE AND VENTILATION CONFINEMENT ZONE CRITERIA FOR THE MGR SURFACE FACILITIES. Office of Scientific and Technical Information (OSTI), 2000. http://dx.doi.org/10.2172/889301.
Texte intégral
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Vanthoor, B. H. E., and I. Tsafaras. Ervaringen met het Ventilation Jet systeem bij Dekker Chrysanten : als onderdeel van het monitoringsproject. Wageningen University & Research, BU Glastuinbouw, 2018. http://dx.doi.org/10.18174/440766.
Texte intégral
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Ellen, Hilko, Yvo Goselink, Jos Huis in ’t Veld, and Albert Winkel. Pilots naar de vermindering van fijnstofemissie uit pluimveestallen : Octafil met recirculatie van VEKO Ventilatie. Wageningen Livestock Research, 2020. http://dx.doi.org/10.18174/527162.
Texte intégral
8
J, Ramos, Novillo F, Nava D, et al. In patients with acute COVID-19, should remdesivir be used compared to placebo? Epistemonikos Interactive Evidence Synthesis, 2023. http://dx.doi.org/10.30846/ies.83ffa48119.
Texte intégralRésumé :
Objective The aim of this living systematic review is to provide a summary of the effects of remdesivir in the of people with acute covid-19. Methods Eligible studies were randomised trials evaluating the effect of remdesivir versus placebo or no treatment. We conducted searches in COVID-19 L·OVE (Living OVerview of Evidence) platform, a system that performs regular searches in databases, trial registries, preprint servers and websites relevant to COVID-19. All the searches covered the period until 06/23/2023. No date or language restrictions were applied. Two reviewers independently evaluated potentially eligible studies according to predefined selection criteria, and extracted data on study characteristics, methods, outcomes, and risk of bias, using a predesigned, standardised form. We performed meta-analyses using random-effect models and assessed overall certainty in evidence using the GRADE approach. Results Our search strategy yielded 897 references. 10 randomized controlled trials reported in 15 references met our inclusion criteria and were included in the review. The relative risk of mortality was 0.91 (95% CI 0.83 - 1.00). This means remdesivir reduced the risk of mortality in 9%, compared with placebo or no treatment. In the studies identified in this review 760 people not receiving remdesivir out of 5372 presented the outcome Mortality (141 per 1000) versus 732 out of 5790 in the group that did receive it, with a risk difference of -12.22 per 1000 (from -24 to 0). In other words, -12.22 per 1000 (from -24 to 0) people did not develop the outcome because of the intervention. We assessed the certainty of the evidence for this outcome as low. The estimated absolute effect, -12.22 per 1000 (from -24 to 0), falls in the range of an effect of small magnitude. The relative risk of mechanical ventilation requirement was 0.62 (95% CI 0.40 - 0.94). This means placebo or no treatment reduced the risk of mechanical ventilation requirement by 38%, compared with . In the studies identified in this review 710 people not receiving placebo or no treatment out of 4539 presented the outcome Mechanical ventilation requirement (156 per 1000) versus 616 out of 4920 in the group that did receive it, with a risk difference of -60.11 per 1000 (from -93 to -10). In other words, -60.11 per 1000 (from -93 to -10) people did not develop the outcome because of the intervention. We assessed the certainty of the evidence for this outcome as low. The estimated absolute effect, -60.11 per 1000 (from -93 to -10), falls in the range of an effect of moderate magnitude. The relative risk of serious adverse events was 0.75 (95% CI 0.60 - 0.92). This means reduced the risk of serious adverse events by 25%, compared with . In the studies identified in this review 266 people not receiving out of 1266 presented the outcome Serious adverse events (210 per 1000) versus 266 out of 1665 in the group that did receive it, with a risk difference of -53.38 per 1000 (from -84 to -16). In other words, -53.38 per 1000 (from -84 to -16) people did not develop the outcome because of the intervention. We assessed the certainty of the evidence for this outcome as moderate. The estimated absolute effect, -53.38 per 1000 (from -84 to -16), falls in the range of an effect of moderate magnitude. Conclusions Remdesivir may result in a slight reduction in mortality. Remdesivir may result in a reduction in mechanical ventilation requirement. Remdesivir probably results in a reduction in serious adverse events.
9
J, Ramos, Novillo F, Nava D, et al. In patients with acute COVID-19, should remdesivir be used compared to placebo? Epistemonikos Interactive Evidence Synthesis, 2023. http://dx.doi.org/10.30846/ies.83ffa48119.v1.
Texte intégralRésumé :
Objective The aim of this living systematic review is to provide a summary of the effects of remdesivir in the of people with acute covid-19. Methods Eligible studies were randomised trials evaluating the effect of remdesivir versus placebo or no treatment. We conducted searches in COVID-19 L·OVE (Living OVerview of Evidence) platform, a system that performs regular searches in databases, trial registries, preprint servers and websites relevant to COVID-19. All the searches covered the period until 06/23/2023. No date or language restrictions were applied. Two reviewers independently evaluated potentially eligible studies according to predefined selection criteria, and extracted data on study characteristics, methods, outcomes, and risk of bias, using a predesigned, standardised form. We performed meta-analyses using random-effect models and assessed overall certainty in evidence using the GRADE approach. Results Our search strategy yielded 897 references. 10 randomized controlled trials reported in 15 references met our inclusion criteria and were included in the review. The relative risk of mortality was 0.91 (95% CI 0.83 - 1.00). This means remdesivir reduced the risk of mortality in 9%, compared with placebo or no treatment. In the studies identified in this review 760 people not receiving remdesivir out of 5372 presented the outcome Mortality (141 per 1000) versus 732 out of 5790 in the group that did receive it, with a risk difference of -12.22 per 1000 (from -24 to 0). In other words, -12.22 per 1000 (from -24 to 0) people did not develop the outcome because of the intervention. We assessed the certainty of the evidence for this outcome as low. The estimated absolute effect, -12.22 per 1000 (from -24 to 0), falls in the range of an effect of small magnitude. The relative risk of mechanical ventilation requirement was 0.62 (95% CI 0.40 - 0.94). This means placebo or no treatment reduced the risk of mechanical ventilation requirement by 38%, compared with . In the studies identified in this review 710 people not receiving placebo or no treatment out of 4539 presented the outcome Mechanical ventilation requirement (156 per 1000) versus 616 out of 4920 in the group that did receive it, with a risk difference of -60.11 per 1000 (from -93 to -10). In other words, -60.11 per 1000 (from -93 to -10) people did not develop the outcome because of the intervention. We assessed the certainty of the evidence for this outcome as low. The estimated absolute effect, -60.11 per 1000 (from -93 to -10), falls in the range of an effect of moderate magnitude. The relative risk of serious adverse events was 0.75 (95% CI 0.60 - 0.92). This means reduced the risk of serious adverse events by 25%, compared with . In the studies identified in this review 266 people not receiving out of 1266 presented the outcome Serious adverse events (210 per 1000) versus 266 out of 1665 in the group that did receive it, with a risk difference of -53.38 per 1000 (from -84 to -16). In other words, -53.38 per 1000 (from -84 to -16) people did not develop the outcome because of the intervention. We assessed the certainty of the evidence for this outcome as moderate. The estimated absolute effect, -53.38 per 1000 (from -84 to -16), falls in the range of an effect of moderate magnitude. Conclusions Remdesivir may result in a slight reduction in mortality. Remdesivir may result in a reduction in mechanical ventilation requirement. Remdesivir probably results in a reduction in serious adverse events.
10
Ramos-Rojas, José, Francisco Novillo, Daniel Nava, et al. In patients with acute COVID-19, should remdesivir be used compared to placebo? Epistemonikos Interactive Evidence Synthesis, 2023. http://dx.doi.org/10.30846/ies.sr1000.
Texte intégralRésumé :
The aim was to assess the efficacy of remdesivir in people with acute covid-19 compared with placebo. Eligible studies were randomised trials evaluating the effect of remdesivir versus placebo. We conducted searches in COVID-19 L·OVE (Living OVerview of Evidence) platform, a system that performs regular searches in databases, trial registries, preprint servers and websites relevant to COVID-19. All the searches covered the period until 06/23/2023. No date or language restrictions were applied. Two reviewers independently evaluated potentially eligible studies according to predefined selection criteria, and extracted data on study characteristics, methods, outcomes, and risk of bias, using a predesigned, standardised form. We performed meta-analyses using random-effect models and assessed overall certainty in evidence using the GRADE approach. Results: our search strategy yielded 132 references. 10 randomized controlled trials reported in 15 references met our inclusion criteria and were included in the review. The relative risk of mortality was 0.92 (95% CI 0.83 - 1.01). This means remdesivir reduced the risk of mortality in 8%, compared with placebo. In the studies identified in this review 762 people not receiving remdesivir out of 5340 presented the outcome Mortality (143 per 1000) versus 734 out of 5477 in the group that did receive it, with a risk difference of -12 per 1000 (from -24 to 1). In other words, -12 per 1000 (from -24 to 1) people did not develop the outcome because of the intervention. We assessed the certainty of the evidence for this outcome as low. The estimated absolute effect, -12 per 1000 (from -24 to 1), falls in the range of an effect of small magnitude. The relative risk of mechanical ventilation requirement was 0.71 (95% CI 0.41 - 1.24). This means placebo reduced the risk of mechanical ventilation requirement in 29%, compared with . In the studies identified in this review 189 people not receiving placebo out of 989 presented the outcome Mechanical ventilation requirement (191 per 1000) versus 182 out of 1195 in the group that did receive it, with a risk difference of -55 per 1000 (from -113 to 46). In other words, -55 per 1000 (from -113 to 46) people did not develop the outcome because of the intervention. We assessed the certainty of the evidence for this outcome as very low. The estimated absolute effect, -55 per 1000 (from -113 to 46), falls in the range of an effect of moderate magnitude. The relative risk of serious adverse events was 0.74 (95% CI 0.57 - 0.95). This means reduced the risk of serious adverse events in 26%, compared with . In the studies identified in this review 265 people not receiving out of 1238 presented the outcome Serious adverse events (214 per 1000) versus 256 out of 1401 in the group that did receive it, with a risk difference of -56 per 1000 (from -91 to -10). In other words, -56 per 1000 (from -91 to -10) people did not develop the outcome because of the intervention. We assessed the certainty of the evidence for this outcome as moderate. The estimated absolute effect, -56 per 1000 (from -91 to -10), falls in the range of an effect of moderate magnitude. Conclusions: Remdesivir may result in a slight reduction in Mortality. Remdesivir may reduce the Mechanical ventilation requirement but the evidence is very uncertain. Remdesivir probably results in a reduction in Serious adverse events.