921 resultados para Effective alveolar ventilation


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BACKGROUND: Compared with usual care, noninvasive ventilation (NIV) lowers the risk of intubation and death for subjects with respiratory failure secondary to COPD exacerbations, but whether administration of NIV by a specialized, dedicated team improves its efficiency remains uncertain. Our aim was to test whether a dedicated team of respiratory therapists applying all acute NIV treatments would reduce the risk of intubation or death for subjects with COPD admitted for respiratory failure. METHODS: We carried out a retrospective study comparing subjects with COPD admitted to the ICU before (2001-2003) and after (2010-2012) the creation of a dedicated NIV team in a regional acute care hospital. The primary outcome was the risk of intubation or death. The secondary outcomes were the individual components of the primary outcome and ICU/hospital stay. RESULTS: A total of 126 subjects were included: 53 in the first cohort and 73 in the second. There was no significant difference in the demographic characteristics and severity of respiratory failure. Fifteen subjects (28.3%) died or had to undergo tracheal intubation in the first cohort, and only 10 subjects (13.7%) in the second cohort (odds ratio 0.40, 95% CI 0.16-0.99, P = .04). In-hospital mortality (15.1% vs 4.1%, P = .03) and median stay (ICU: 3.1 vs 1.9 d, P = .04; hospital: 11.5 vs 9.6 d, P = .04) were significantly lower in the second cohort, and a trend for a lower intubation risk was observed (20.8% vs 11% P = .13). CONCLUSIONS: The delivery of NIV by a dedicated team was associated with a lower risk of death or intubation in subjects with respiratory failure secondary to COPD exacerbations. Therefore, the implementation of a team administering all NIV treatments on a 24-h basis should be considered in institutions admitting subjects with COPD exacerbations.

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The effective notch stress approach for the fatigue strength assessment of welded structures as included in the Fatigue Design Recommendation of the IIW requires the numerical analysis of the elastic notch stress in the weld toe and weld root which is fictitiously rounded with a radius of 1mm. The goal of this thesis work was to consider alternate meshing strategies when using the effective notch stress approach to assess the fatigue strength of load carrying partial penetration fillet-welded cruciform joints. In order to establish guidelines for modeling the joint and evaluating the results, various two-dimensional (2D) finite element analyses were carried out by systematically varying the thickness of the plates, the weld throat thickness, the degree of bending, and the shape and location of the modeled effective notch. To extend the scope of this work, studies were also carried out on the influence of

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Energy consumption and energy efficiency have become an issue. Energy consumption is rising all over the world and because of that, and the climate change, energy is becoming more and more expensive. Buildings are major consumers of energy, and inside the buildings the major consumers are heating, ventilation and air-conditioning systems. They usually run at constant speed without efficient control. In most cases HVAC equipment is also oversized. Traditionally heating, ventilation and air-conditioning systems have been sized to meet conditions that rarely occur. The theory part in this thesis represents the basics of life cycle costs and calculations for the whole life cycle of a system. It also represents HVAC systems, equipment, systems controls and ways to save energy in these systems. The empirical part of this thesis represents life cycle cost calculations for HVAC systems. With these calculations it is possible to compute costs for the whole life cycle for the wanted variables. Life cycle costs make it possible to compare which variable causes most of the costs from the whole life point of view. Life cycle costs were studied through two real life cases which were focused on two different kinds of HVAC systems. In both of these cases the renovations were already made, so that the comparison between the old and the new, now existing system would be easier. The study indicates that energy can be saved in HVAC systems by using variable speed drive as a control method.

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Rakennustyömaa on yksi vaarallisimpia ja työolosuhteiltaan haastavimpia työpaikkoja. Sisävalmistusvaiheessa ongelmaksi muodostuu töiden tuottama pöly ja melu. Työmaan epäjärjestys ja likaisuus lisäävät tapaturmariskiä. Pölytöntä rakennustyömaata ei ole olemassa ja tästä syystä pölynhallinta muodostuu merkittäväksi tekijäksi pölyn leviämisen rajoittamisessa. Työn tavoitteena oli tutkia teknisiä pölynhallintakeinoja, joilla voidaan vähentää henkilökohtaisen suojauksen tarvetta rakennustyömailla. Pölynhallintaan työmailla voidaan vaikuttaa työtapojen ja -menetelmien valinnalla, töiden vaiheistuksella, kohdepoistoilla, osastoinnilla ja alipaineistuksella. Työssä oli tarkoitus myös verrata ja tutkia erilaisten ja eri työvaiheisiin tarkoitettujen pölynhallintalaitteistojen toimintaa ja niiden toimivuutta pölynhallinnassa. Tämä tutkimus toteutettiin Savocon Oy:n Kuopioon rakennettavan Turontähden rakennustyömaalla huhti- ja toukokuussa 2008. Tutkimusten perusteella tekniset pölynhallintakeinot toimivat kohtalaisen hyvin. Hiomalaitteissa pölynhallinta on tekninen ominaisuus, mutta sen toimivuus riippuu myös siitä, osaako työntekijä hyödyntää pölynhallintaa oikealla tavalla. Toimintaan vaikuttaa se, osaavatko laitteen käyttäjät asettaa imutehon sellaiseksi, että se on riittävän suuri poistamaan pölyn, mutta ei liian suuri haitatakseen työntekoa ja saaden aikaan heikkoa työnjälkeä. Oikeat laiteasetukset opitaan kokeilemalla. Imutehon säätömahdollisuus on erilaisten pintatasoitteiden myötä erityisen tärkeä laiteominaisuus. Timanttihiomalaitteilla saavutetut pölynpoistotehokkuudet olivat kaikki yli 97 prosenttia, kun niiden tehoa verrattiin ilman pölynpoistoa tapahtuvaan timanttihiontaan. Timanttihiontaa ei suositella tehtäväksi ilman pölynpoistotekniikkaa, sillä pölyntuotto on suurta ja pölypitoisuudet nousevat nopeasti hyvin suuriksi ja työntekijöiden altistus pölylle kasvaa. Ilmanpuhdistimien tehot riittivät pienen tilan ilman puhdistamiseen, mutta suurissa tiloissa ja suurissa pitoisuuksissa teho jäi riittämättömäksi. Oikein mitoitettuina ilmanpuhdistimia voidaan suositella kohdepoistolla toimivien laitteiden lisäksi huonetilaan puhdistamaan vähäiset hiukkaspäästöt, joita laitteista tulee. Teollisuusimurien valinnassa huomio tulee kiinnittää moottorin imutehoon, moottorin jäähdytyksen järjestelyyn, pölypussin materiaaliin ja pölypussin tyhjennysmekanismiin. Näillä on suuri merkitys siivoustyön pölyttömämpään lopputulokseen. Tämän työn käyttö markkinointitarkoituksessa ilman tekijän lupaa on kielletty.

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Une ventilation artificielle avec un volume courant excessif génère dans le poumon une tension et une contrainte élevées, susceptibles d'engendrer des lésions. La situation de l'SDRA, dans laquelle le volume pulmonaire disponible est fortement réduit (baby lung), a permis de bien comprendre ces mécanismes lésionnels. Ceci a permis d'établir des stratégies ventilatoires protectrices efficaces. Cette problématique est également pertinente pour des poumons non lésés au préalable, situation dans laquelle une ventilation protectrice devrait aussi s'appliquer.

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Craving is considered the main variable associated with relapse after smoking cessation. Cue Exposure Therapy (CET) consists of controlled and repeated exposure to drug-related cues with the aim of extinguishing craving responses. Some virtual reality (VR) environments, such as virtual bars or parties, have previously shown their efficacy as tools for eliciting smoking craving. However, in order to adapt this technology to smoking cessation interventions, there is a need for more diverse environments that enhance the probability of generalization of extinction in real life. The main objective of this study was to identify frequent situations that produce smoking craving, as well as detecting specific craving cues in those contexts. Participants were 154 smokers who responded to an ad hoc self-administered inventory for assessing craving level in 12 different situations. Results showed that having a drink in a bar/pub at night, after having lunch/dinner in a restaurant and having a coffee in a cafe or after lunch/dinner at home were reported as the most craving-inducing scenarios. Some differences were found with regard to participants' gender, age, and number of cigarettes smoked per day. Females, younger people, and heavier smokers reported higher levels of craving in most situations. In general, the most widely cited specific cues across the contexts were people smoking, having a coffee, being with friends, and having finished eating. These results are discussed with a view to their consideration in the design of valid and reliable VR environments that could be used in the treatment of nicotine addicts who wish to give up smoking.

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Communication between trainer and trainee plays a central role in teaching and learning in the clinical environment. There are various strategies to frame the dialogue between trainee and trainer. These strategies allow trainers to be more effective in their supervision, which is important in our busy clinical environment. Communication strategies are well adapted to both in- and out-patient settings, to both under- and postgraduate contexts. This article presents three strategies that we think are particularly useful. They are meant to give feedback, to ask questions and to present a case.

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Relatamos o caso de uma mulher de 21 anos com história de seis meses de dispneia progressiva, tosse seca e perda de peso. A tomografia computadorizada de alta resolução revelou padrão de pavimentação em mosaico com áreas focais poupadas. A paciente foi submetida a biópsia pulmonar transbrônquica, que confirmou o diagnóstico de proteinose alveolar. Dois anos depois, sem tratamento, houve importante melhora das opacidades pulmonares.

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QUESTION UNDER STUDY: To test longitudinally differences in conventional cigarette use (cigarettes smoked, cessation, quit attempts) between vapers and nonvapers. METHODS: Fifteen months follow-up of a sample of 5 128 20-year-old Swiss men. The onset of conventional cigarette (CC) use among nonsmokers, and smoking cessation, quit attempts, changes in the number of CCs smoked among smokers at baseline were compared between vapers and nonvapers at follow-up, adjusted for nicotine dependence. RESULTS: Among baseline nonsmokers, vapers were more likely to start smoking at follow-up than nonvapers (odds ratio [OR] 6.02, 95% confidence interval [CI] 2.81, 12.88 for becoming occasional smokers, and OR = 12.69, 95% CI 4.00, 40.28 for becoming daily smokers). Vapers reported lower smoking cessation rates among occasional smokers at baseline (OR = 0.43 (0.19, 0.96); daily smokers: OR = 0.42 [0.15, 1.18]). Vapers compared with nonvapers were heavier CC users (62.53 vs 18.10 cigarettes per week, p <0.001) and had higher nicotine dependence levels (2.16 vs 0.75, p <0.001) at baseline. The number of CCs smoked increased between baseline and follow-up among occasional smokers (b = 6.06, 95% CI 4.44, 7.68) and decreased among daily smokers (b = -5.03, 95% CI -8.69, -1.38), but there were no differential changes between vapers and nonvapers. Vapers showed more quit attempts at follow-up compared with nonvapers for baseline occasional smokers (incidence rate ratio [IRR] 1.81, 95% CI 1.24, 2.64; daily smokers IRR 1.28, 95% CI 0.95, 1.73). CONCLUSIONS: We found no beneficial effects of vaping at follow-up for either smoking cessation or smoking reduction.