12 research outputs found

    Pago de potencia a través de opciones: perspectivas de aplicación al mercado eléctrico del Ecuador

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    En la actualidad los mercados de energía eléctrica pasan por una profunda reestructuración; especialmente en la creación de instrumentos para agilitar las transacciones y reducir el riesgo comercial entre los diferentes agentes del mercado eléctrico. El riesgo comercial, aparece debido a la disponibilidad de las unidades y centrales de generación que forman el sector eléctrico de manera especial el caudal de los ríos que alimentan a las centrales hidroeléctricas que poseen una elevada aleatoriedad. Esto hace que el sistema hidrotérmico presente precios muy volátiles los cuales dependan de la disponibilidad del parque generador. En las primeras etapas de la reestructuración todos los esfuerzos se han centrado en resolver los problemas particulares de cada mercado; de esa manera tender a la creación de mercados suficientemente líquidos y con una adecuada estructura competitiva, todo ello encaminado a garantizar que la oferta de energía se adecue a la demanda en todo momento, más las señales económicas para la oferta de generación; debe buscar ser estables y con mecanismos claros y transparentes para todos los agentes lo que permita la instalación de capacidad de potencia disponible en el sistema y con ello sea sustentable el sistema de una manera técnica, política como económicamente. Dichas características la presentan los mercados financieros específicamente las opciones. Para poder enfrentar estos inconvenientes presentes en el mercado, resulta útil analizar a otros mercados con características similares; el presente trabajo realiza el estudio del mercado de opciones para la remuneración de potencia aplicado al sector eléctrico y la aplicabilidad de esta metodología en Ecuador

    Bronchial infection and temporal evolution of bronchiectasis in patients with chronic obstructive pulmonary disease

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    Background: Bronchiectasis (BE) impact the clinical course and prognosis of patients with chronic obstructive pulmonary disease (COPD). Yet, the temporal evolution of BE in these patients is unknown. This study seeks to assess the temporal evolution of BE in persons with COPD. Methods: 201 moderate-to-severe patients were recruited between 2004 and 2007 and followed up at least every 6 monts (median of 102 months). To investigate the temporal evolution of BE, in 2015 a second high-resolution computed tomography scan (HRCT) was obtained in survivors and compared with the one obtained at recruitment. Results: 99 (49.3%) died during follow-up. The second HRCT could be obtained in 77 patients and showed that (1) in 27.3% of patients BE never developed, in 36.4% they remained stable, in 16.9% they increased in size and/or extension, and in 19.5% new BE emerged; and that (2) the presence of chronic purulent sputum (hazard ratio [HR], 2.8 [95% confidence interval {CI}, 1.3-5.8]), number of hospitalizations due to exacerbatons (HR, 1.2 [95% CI, 1.1-1.5]), and number of pathogenic microorganism (PPM) isolations (HR, 1.1 [95% CI, 1.02-1.3]) were independent risk factors for the progression or development of BE. Conclusions: The presence of chronic purulent sputum production, number of PPMs isolated in sputum, and number of hospitalizations due to exacerbations of COPD are independent risk factors of BE progression in patients with COPD

    Treatment with CPAP in Elderly Patients with Obstructive Sleep Apnoea

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    The population pyramid is changing as a result of the ever-increasing life expectancy, which makes it crucial to acquire an in-depth understanding of the diseases that most often affect the elderly. Obstructive sleep apnoea (OSA) affects 15%–20% of the population aged over 65 years. Despite this prevalence, there have been very few specific studies on the management of OSA in this age group, even though over 60% of the patients aged over 65-70 years who attend sleep units with suspicion of OSA receive treatment with continuous positive airway pressure (CPAP), on the basis of an extrapolation of the positive results achieved by CPAP in clinical trials involving middle-aged males. However, the latter’s form of presentation, evolution and, probably, prognosis comparing with OSA are not the same as those of elderly patients. Recent clinical trials performed on an exclusive series of elderly patients have shed light on the possible role of CPAP treatment in elderly patients with OSA, but there are still many questions that need to be answered. The physiological increase in the number of sleep-related disorders with the passing of years, and the lack of validated diagnostic and therapeutic tools for this age group are probably the greatest obstacles to define, diagnose and treat OSA in the elderly

    Inhaled steroids, circulating eosinophils, chronic airway infection, and pneumonia risk in chronic obstructive pulmonary disease: a network analysis.

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    Rationale: Treatment of chronic obstructive pulmonary disease (COPD) with inhaled corticosteroids (ICS) is controversial, because it can reduce the risk of future exacerbations of the disease at the expense of increasing the risk of pneumonia.Objectives: To assess the relationship between the presence of chronic bronchial infection (CBI), reduced number of circulating eosinophils, ICS treatment, and the risk of pneumonia in patients with COPD.Methods: This was a post hoc long-term observational study of an historical cohort of 201 patients with COPD (Global Initiative for Chronic Obstructive Lung Disease II-IV) who were carefully characterized (including airway microbiology) and followed for a median of 84 months. Results were analyzed by multivariate Cox regression and network analysis.Measurements and Main Results: Mean age was 70.3 years, 90.5% of patients were male, mean FEV1 was 49%, 71.6% of patients were treated with ICS, 57.2% of them had bronchiectasis, and 20.9% had <100 blood eosinophils/μl. Pathogenic microorganisms were isolated in 42.3% of patients, and 22.4% of patients fulfilled the definition of CBI. During follow-up, 38.8% of patients suffered one or more episodes of pneumonia, with CBI (hazard ratio [HR], 1.635) and <100 eosinophils/μl (HR, 1.975) being independently associated with the risk of pneumonia, particularly when both coexist (HR, 3.126). ICS treatment increased the risk of pneumonia in those patients with <100 eosinophils/μl and CBI (HR, 2.925).Conclusions: Less than 100 circulating eosinophils/μl combined with the presence of CBI increase the risk of pneumonia in patients with COPD treated with ICS

    Chronic bronchial infection and incident cardiovascular events in chronic obstructive pulmonary disease patients: A long-term observational study

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    Background and objective: Cardiovascular (CV) diseases are frequent in patients with chronic obstructive pulmonary disease (COPD). Likewise, chronic bronchial infection (CBI) is also frequent in COPD and it is associated with systemic inflammation, a well-known CV risk factor. The objective of this study was to investigate the relationship between CBI, systemic inflammation and incident CV events. Methods: A post hoc analysis of prospectively collected cohort of 201 COPD patients [Global Initiative for Chronic Obstructive Lung Disease (GOLD) II-IV] followed up every 3-6 months for 84 months was conducted. CBI was defined as ≥3 positive pathogenic microorganisms sputum cultures over 1 year, separated by ≥3 months. Systemic inflammation was assessed by circulating levels of C-reactive protein and fibrinogen. Fatal and non-fatal CV events, including coronary and cerebrovascular events as well as arrhythmia episodes, were prospectively recorded. For analysis, they were analysed separately and combined in a composite variable. Results: As hypothesized, CBI was associated with persistent systemic inflammation and a significantly higher incidence of CV events (HR: 3.88; 95% CI: 1.83-8.22), mainly of coronary origin independent of age, number and severity of exacerbations, comorbidities, other CV risk factors, lung function, BMI, smoking status and treatments. These associations were particularly significant in patients with CBI by Pseudomonas aeruginosa (PA). Conclusion: CBI, particularly by PA, is associated with sustained and enhanced systemic inflammation and a higher incidence of CV events (especially coronary events). The possibility that treating CBI may decrease systemic inflammation and CV events in COPD deserves prospective, interventional studies
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