Respuesta sísmica de componentes no estructurales sensibles a la aceleración en un Edificio de media altura con muros delgados de hormigón ligeramente reforzado (TLRCW)

24 páginasExperience in recent earthquakes has shown that Non-Structural Components (NSCs) in multi-story buildings exert a significant influence on economic losses. Different topics about the seismic behavior of NSCs have been investigated; however more research is needed in several areas such as the type of building structural system and the type of seismic hazard. Motivated by this observation, floor accelerations in a novel structural system, namely the Thin and Lightly-Reinforced Concrete Wall (TLRCW) building, are examined in this paper. The TLRCW system comprises thin and slender walls with deficient or nonexistent confinement at the wall edges, and web reinforcements made of welded-wire mesh with limited ductility. In this study, seismic demands on NSCs in a TLRCW building are analytically calculated and compared with current characterizations included in earthquake-resistant building codes and presented in the literature. Comparisons are performed in terms of peak floor accelerations, floor spectra, inelastic displacement ratios, and the still not completely characterized inelastic absolute acceleration ratios. Influence of elastic and inelastic behavior of NSCs as well as of the structure is also evaluated. Since the TLRCW system is becoming common in some South American countries prone (in part or wholly) to subduction earthquakes, possible influence of the type of seismic hazard (i.e., crustal earthquakes or subduction earthquakes) is accounted for. It was found that, under design-level seismic demands, floor accelerations can be very large even though the structure undergoes a significant level of inelastic excursion. It was also found that floor accelerations are, for the most part, reasonably approximated by current characterizations. Finally, the type of seismic hazard has a negligible qualitative influence on floor accelerations (only minor quantitative differences were found).La experiencia de terremotos recientes ha demostrado que los componentes no estructurales (NSC) en edificios de varios pisos ejercer una influencia significativa sobre las pérdidas económicas. Se han tratado diferentes temas sobre el comportamiento sísmico de las NSC. investigado; Sin embargo, se necesita más investigación en varias áreas, como el tipo de sistema estructural del edificio y el tipo de peligro sísmico. Motivados por esta observación, las aceleraciones del piso en un nuevo sistema estructural, a saber el edificio de muros de hormigón delgado y ligeramente reforzado (TLRCW), se examinan en este artículo. El TLRCW El sistema comprende paredes delgadas y esbeltas con confinamiento deficiente o inexistente en los bordes de la pared, y red. refuerzos de malla electrosoldada de ductilidad limitada. En este estudio, las demandas sísmicas sobre los NSC en un El edificio TLRCW se calcula analíticamente y se compara con las caracterizaciones actuales incluidas en códigos de construcción resistentes a terremotos y presentados en la literatura. Las comparaciones se realizan en términos de pico aceleraciones del suelo, espectros del suelo, relaciones de desplazamiento inelásticas y las relaciones de aceleración absoluta inelástica aún no completamente caracterizadas. La influencia del comportamiento elástico e inelástico de las NSC, así como de la estructura, es también evaluado. Dado que el sistema TLRCW se está volviendo común en algunos países sudamericanos propensos (en parte o totalmente) a los terremotos de subducción, posible influencia del tipo de peligro sísmico (es decir, terremotos de la corteza terrestre o terremotos de subducción). Se encontró que, bajo las demandas sísmicas a nivel de diseño, las aceleraciones del piso pueden ser muy grandes incluso aunque la estructura experimente un nivel significativo de excursión inelástica. Fue También descubrieron que las aceleraciones del suelo son, en su mayor parte, razonablemente aproximadas a las caracterizaciones actuales. Finalmente, el tipo de peligro sísmico tiene una influencia cualitativa insignificante en las aceleraciones del piso (sólo una menor se encontraron diferencias cuantitativas)

Risk factors for mortality in Reoperations for Pediatric and Congenital Heart Surgery in a Developing Country

Background: The survival of patients with congenital heart disease has increased in the recent years, because of enhanced diagnostic capabilities, better surgical techniques and improved perioperative care. Many patients will require reoperations as part of staged procedures, or to treat grafts deterioration and residual or recurrent lesions. Reoperations favor the formation of cardiac adhesions and consequently increase surgery time, however, the impact on morbidity and operative mortality is certain. The objective of the study was to describe the risk factors for mortality in pediatric patients undergoing a reoperation for congenital heart disease. Methods: Historic cohort of patients who underwent reoperations after pediatric cardiac surgery from January 2009 to December 2015. Operations with previous surgical approach different to sternotomy were excluded from the analysis. Results: In seven years, 3.086 surgeries were performed, 481 were reoperations and 238 patients fulfilled the inclusion criteria. Mean number of prior surgeries was 1.4 ± 0.6. Median age at the time of reoperation was 6.4 years. The most common surgical procedures were staged palliation for functionally univentricular heart (17.6%). Median cross clamp time was 66 minutes. Younger age at the moment of resternotomy, longer cross clamp time and a STAT risk category greater than 3 were risk factors for mortality. The number of resternotomies was not associated to mortality. Mortality prior to hospital discharge was 4.6% and mortality after discharge but prior to 30 days after surgery was 0.54%. Operative Mortality was 5.1%. Conclusions: Resternotomy in pediatric cardiac surgery is a safe procedure in our center

Risk factors for mortality in Reoperations for Pediatric and Congenital Heart Surgery in a Developing Country

Background: The survival of patients with congenital heart disease has increased in the recent years, because of enhanced diagnostic capabilities, better surgical techniques and improved perioperative care. Many patients will require reoperations as part of staged procedures, or to treat grafts deterioration and residual or recurrent lesions. Reoperations favor the formation of cardiac adhesions and consequently increase surgery time, however, the impact on morbidity and operative mortality is certain. The objective of the study was to describe the risk factors for mortality in pediatric patients undergoing a reoperation for congenital heart disease. Methods: Historic cohort of patients who underwent reoperations after pediatric cardiac surgery from January 2009 to December 2015. Operations with previous surgical approach different to sternotomy were excluded from the analysis. Results: In seven years, 3.086 surgeries were performed, 481 were reoperations and 238 patients fulfilled the inclusion criteria. Mean number of prior surgeries was 1.4 ± 0.6. Median age at the time of reoperation was 6.4 years. The most common surgical procedures were staged palliation for functionally univentricular heart (17.6%). Median cross clamp time was 66 minutes. Younger age at the moment of resternotomy, longer cross clamp time and a STAT risk category greater than 3 were risk factors for mortality. The number of resternotomies was not associated to mortality. Mortality prior to hospital discharge was 4.6% and mortality after discharge but prior to 30 days after surgery was 0.54%. Operative Mortality was 5.1%. Conclusions: Resternotomy in pediatric cardiac surgery is a safe procedure in our center.2019-08-01 06:01:01: Script de automatizacion de embargos. info:eu-repo/date/embargoEnd/2019-04-2

Mechanical circulatory support as bridge therapy for heart transplant: case series report

Abstract Background Mechanical circulatory support (MCS) represents an effective urgent therapy for patients with cardiac arrest or end-stage cardiac failure. However, its use in developing countries as a bridge therapy remains controversial due to costs and limited duration. This study presents five patients who underwent MSC as bridge therapy for heart transplantation in a developing country. Case presentation We present five patients who underwent MCS as bridge therapy for heart transplant between 2010 and 2015 at Fundación Cardioinfantil-Instituto de Cardiología. Four were male, median age was 36 (23–50) years. One patient had an ischemic cardiomyopathy, one a lymphocytic myocarditis, two had electrical storms (recurrent ventricular tachycardia) and one an ischemic cardiomyopathy with an electrical storm. Extracorporeal life support (ECLS) was used in three patients, left ventricular assistance in one, and double ventricular assistance in one (Levitronix® Centrimag®). Median assistance time was 8 (2.5–13) days. Due to the inability of cardiopulmonary bypass weaning, two patients required ECLS after transplant. One patient died in the intensive care unit due to type I graft rejection. Endpoints assessed were 30-day mortality, duration of bridge therapy and complications related to MCS. Patients that died on ECLS, or were successfully weaned off ECLS were not included in this study. Conclusions MCS is often the only option of support for critically ill patients waiting for a heart transplant and could be considered as a short-term bridge therapy

Mechanical circulatory support as bridge therapy for heart transplant: Case series report

Background: Mechanical circulatory support (MCS) represents an effective urgent therapy for patients with cardiac arrest or end-stage cardiac failure. However, its use in developing countries as a bridge therapy remains controversial due to costs and limited duration. This study presents five patients who underwent MSC as bridge therapy for heart transplantation in a developing country. Case presentation: We present five patients who underwent MCS as bridge therapy for heart transplant between 2010 and 2015 at Fundación Cardioinfantil-Instituto de Cardiología. Four were male, median age was 36 (23-50) years. One patient had an ischemic cardiomyopathy, one a lymphocytic myocarditis, two had electrical storms (recurrent ventricular tachycardia) and one an ischemic cardiomyopathy with an electrical storm. Extracorporeal life support (ECLS) was used in three patients, left ventricular assistance in one, and double ventricular assistance in one (Levitronix® Centrimag®). Median assistance time was 8 (2.5-13) days. Due to the inability of cardiopulmonary bypass weaning, two patients required ECLS after transplant. One patient died in the intensive care unit due to type I graft rejection. Endpoints assessed were 30-day mortality, duration of bridge therapy and complications related to MCS. Patients that died on ECLS, or were successfully weaned off ECLS were not included in this study. Conclusions: MCS is often the only option of support for critically ill patients waiting for a heart transplant and could be considered as a short-term bridge therapy. © 2018 The Author(s)

Mechanical circulatory support as bridge therapy for heart transplant: Case series report

Background: Mechanical circulatory support (MCS) represents an effective urgent therapy for patients with cardiac arrest or end-stage cardiac failure. However, its use in developing countries as a bridge therapy remains controversial due to costs and limited duration. This study presents five patients who underwent MSC as bridge therapy for heart transplantation in a developing country. Case presentation: We present five patients who underwent MCS as bridge therapy for heart transplant between 2010 and 2015 at Fundación Cardioinfantil-Instituto de Cardiología. Four were male, median age was 36 (23-50) years. One patient had an ischemic cardiomyopathy, one a lymphocytic myocarditis, two had electrical storms (recurrent ventricular tachycardia) and one an ischemic cardiomyopathy with an electrical storm. Extracorporeal life support (ECLS) was used in three patients, left ventricular assistance in one, and double ventricular assistance in one (Levitronix® Centrimag®). Median assistance time was 8 (2.5-13) days. Due to the inability of cardiopulmonary bypass weaning, two patients required ECLS after transplant. One patient died in the intensive care unit due to type I graft rejection. Endpoints assessed were 30-day mortality, duration of bridge therapy and complications related to MCS. Patients that died on ECLS, or were successfully weaned off ECLS were not included in this study. Conclusions: MCS is often the only option of support for critically ill patients waiting for a heart transplant and could be considered as a short-term bridge therapy. © 2018 The Author(s)