Repercussões da estase pulmonar sobre os volumes, capacidades e débitos ventilatórios

Revista Portuguesa de Cardiologia, 1994, 13(10): 763-768.Objectivo: Avaliar as repercussões da estase pulmonar sobre a função pulmonar. Concepção do estudo: Estudo prospectivo executado em doentes com falência ventricular esquerda ou estenose valvular mitral. Material e métodos: Estudaram-se 48 doentes internados por estase pulmonar resultante de falência ventricular esquerda ou barragem mitral. Todos os doentes foram submetidos durante o internamento a exame termodinâmico com catéter de Swan-Ganz e exame ecocardiográfico 48 horas antes das provas funcionais respiratórias,compostas por espirometria com débitos, volumes e capacidades pelo método da diluição de hélio, bem como caracterização da incapacidade funcional com o questionário do Medical Research Council e a classificação da NYHA. Correlacionaram-se os dados espirométricos com os dados clínicos. Resultados: Do ponto de vista cardiológico, os doentes apresentavam uma «pressão capilar pulmonar» média de 19,9 ± 8,6 mmHg, um índice cardíaco de 2,5±0,8 l/mln/m", uma dimensão telediastólica do ventrículo esquerdo de 65,9 ±10,1mm e uma telessistólica de 51,2 ± 12,2 mm com uma fracção de encurtamento de 21,8 ±9,5 %. Espirometricamente, apresentavam uma síndrome restritiva caracterizada por uma diminuição da capacidage pulmonar total de 71±14,4% do valor previsto (%vp), uma capacidade vital forçada de 69,8±20,5 % vp, um volume expiratório máximo no primeiro segundo de 64±21,8 %vp, com uma relação VEMS/CVF normal de 72,7±9,7%. Estes dados não se correlacionaram com os dados clínicos nem com os dados hemodinâmicos ou ecocardiográficos. Conclusão: Neste grupo de doentes, a estase pulmonar tem como consequência uma síndroma restritiva pulmonar, sendo a sua gravidade independente da duração da doença, do valor da «pressão capilar pulmonar» ou da função ventricular esquerda

Aplicação do método de aprendizagem baseado na análise de problemas ao ensino da Fisiopatologia

Educação Médica 1991; 2 (2): 29-40O método de aprendizagem baseado na análise de problemas está a ser utilizado, de uma forma limitada, no ensino da Fisiopatologia desde 1988 e após um ano de preparação dos recursos humanos e materiais. A experiência dos dois primeiros anos revelou que, apesar do método estar apenas a ser aplicado numa única disciplina de um curriculum tradicional, o aproveitamento dos alunos ao longo do ano melhorou e que o mesmo sucedeu no exame final. Os alunos consideraram o método como muito estimulante para a aprendizagem embora trabalhoso. Apesar de terem sido utilizados problemas contendo uma quantidade limitada de informação, os alunos seguiram as várias fases do método de uma forma adequada. No entanto o pessoal docente já decidiu que no próximo ano académico (1991-1992) serão utilizados problemas completos para estimular ainda mais o raciocínio e a aprendizagem num contexto clínico. Summary:A limited version of the problem- based learning method is being used in the discipline of Pathophysiology since 1988 after one year of preparation including both the faculty and the learning materiais. The evaluation of the first two years showed an improvement in the performance of the students both in the final exams and during the year. The students also considered the method very stimulating for learning although they felt the need of an extra effort. Despite the fact that we were using in complete cases the steps of the method were followed. Neverthless the faculty has already decided that in the next academic year (1991-1992), complete cases will be used for further improvement of the reasoning process within the clinical context

Techno-economic assessment of CO2 quality effect on its storage and transport: CO2QUEST: An overview of aims, objectives and main findings

This paper provides an overview of the aims, objectives and the main findings of the CO2QUEST FP7 collaborative project, funded by the European Commission and designed to address the fundamentally important and urgent issues regarding the impact of the typical impurities in CO2 streams captured from fossil fuel power plants and other CO2 intensive industries on their safe and economic pipeline transportation and storage. The main features and results recorded from some of the unique test facilities constructed as part of the project are presented. These include an extensively instrumented realistic-scale test pipeline for conducting pipeline rupture and dispersion tests in China, an injection test facility in France to study the mobility of trace metallic elements contained in a CO2 stream following injection near a shallow-water qualifier and fluid/rock interactions and well integrity experiments conducted using a fully instrumented deep-well CO2/impurities injection test facility in Israel. The above, along with the various unique mathematical models developed, provide the fundamentally important tools needed to define impurity tolerance levels, mixing protocols and control measures for pipeline networks and storage infrastructure, thus contributing to the development of relevant standards for the safe design and economic operation of CCS

An Approach Towards a FEP-based Model for Risk Assessment for Hydraulic Fracturing Operations

AbstractWe consider an exemplary scenario drafted in the context of the recently started EU-project FracRisk. The setting belongs to six scenarios representing diverse subsurface processes on different scales. A numerical approach considering sources, pathways and targets quantifies the environmental impact associated with this setting. A Global Sensitivity Analysis of properly defined output quantities takes into account uncertain parameters and operational conditions within a FEP-based evaluation of risk and counteractive measures. At this early stage of the project, this showcase of the general modeling workflow addresses migration of frac-fluid through a naturally fractured reservoir (source) to an overlying formation (target)

Carbon capture: Whole system experimental and theoretical modeling investigation of the optimal CO<inf>2</inf> stream composition in the carbon capture and sequestration chain

Rapid increase in emissions of greenhouse gases (GHGs) has become a major concern to the global community. This is associated with the rapid growth in population and corresponding increase in energy demand. Combustion of fossil fuels accounts for the majority of CO2 emissions. Coal is used mostly for electricity generation, for instance, about 85.5% of coal (produced and imported) in the United 459Kingdom was used for electricity generation in 2011 [1]. Coal-fired power plants are therefore the largest stationary source of CO2

Role of critical gas saturation in the interpretation of a field scale CO2 injection experiment

Residual trapping of CO2, typically quantified by residual gas saturation (Sgr), is one of the main trapping mechanisms in geological CO2 storage (GCS). An important additional characteristic parameter is critical gas saturation (Sgc). Sgc determines at what saturation the trapped gas remobilizes again if gas saturation increases due to exsolution from the aqueous phase, rather than from further gas injection. In the present study, a pilot-scale CO2 injection experiment carried out at Heletz, Israel, in 2017, is interpreted by taking critical saturation into account. With regards to this experiment, the delayed second arrival peak of the partitioning tracer could not be captured by means of physical models. In this work, the hysteretic relative permeability functions were modified to account for Sgc. The results showed that accounting for the effect of Sgc during the secondary drainage indeed captured the observed delayed peak. The difference between the values of Sgr and Sgc, influenced both the time and peak height of the tracer arrival. To our knowledge this is first time that critical gas saturation has been considered in field scale analyses related to GCS. Accounting for Sgc is relevant where gas saturation during secondary drainage increases due to gas phase expansion or exsolution from the aqueous phase. This will happen in situations where pressure depletion occurs, e.g. due to gas leakage from fracture zones or wells or possibly because of pressure management activities. The findings also have implications for other applications such as underground gas storage as well as for geothermal reservoir management

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2D reactive transport simulations of CO2 streams containing impurities in a saline aquifer, Heletz, Israel

In order to evaluate the chemical impacts of CO2 stream impurities on reservoir rocks, 2D reactive transport simulations using the code TOUGHREACT V3.0 were performed. The underlying reservoir properties are based on in-situ data from the CO2 injection test site Heletz, Israel. Two different CO2 compositions (mole fractions 99 % CO2 + 1 % SO2 and 98.8 % CO2 + 1 % SO2 + 0.2 % NO2, respectively) were chosen to represent oxidising impurities. Different modelling approaches, namely trace gas transport (TGT) and additional brine injection (ABI), were applied to investigate the influence of these modelling approaches on qualitative and quantitative simulation results. The simulations using either approach show an accumulation of SO2 and NO2 close to the injection well due to the preferential dissolution of these acidic impurities compared to CO2. Both modelling approaches indicate the same general chemical impact and related mineral reactions. Within the affected rock volume a distinct ankerite to anhydrite conversion occurs, which slightly enhances porosity. While the same qualitative conclusions independently from the chosen modelling approach were obtained, the quantitative magnitude of mineral conversion and the spatial extent of impurity affected rock material depend on the chosen modelling approach and thus need further investigation with respect to e.g. validation by field test data. (C) 2017 The Authors. Published by Elsevier Ltd