Optimal Taylor-Couette flow: Radius ratio dependence

Taylor-Couette flow with independently rotating inner (i) and outer (o) cylinders is explored numerically and experimentally to determine the effects of the radius ratio {\eta} on the system response. Numerical simulations reach Reynolds numbers of up to Re_i=9.5 x 10^3 and Re_o=5x10^3, corresponding to Taylor numbers of up to Ta=10^8 for four different radius ratios {\eta}=r_i/r_o between 0.5 and 0.909. The experiments, performed in the Twente Turbulent Taylor-Couette (T^3C) setup, reach Reynolds numbers of up to Re_i=2x10^6$ and Re_o=1.5x10^6, corresponding to Ta=5x10^{12} for {\eta}=0.714-0.909. Effective scaling laws for the torque J^{\omega}(Ta) are found, which for sufficiently large driving Ta are independent of the radius ratio {\eta}. As previously reported for {\eta}=0.714, optimum transport at a non-zero Rossby number Ro=r_i|{\omega}_i-{\omega}_o|/[2(r_o-r_i){\omega}_o] is found in both experiments and numerics. Ro_opt is found to depend on the radius ratio and the driving of the system. At a driving in the range between {Ta\sim3\cdot10^8} and {Ta\sim10^{10}}, Ro_opt saturates to an asymptotic {\eta}-dependent value. Theoretical predictions for the asymptotic value of Ro_{opt} are compared to the experimental results, and found to differ notably. Furthermore, the local angular velocity profiles from experiments and numerics are compared, and a link between a flat bulk profile and optimum transport for all radius ratios is reported.Comment: Submitted to JFM, 28 pages, 17 figure

Estudio sobre la automedicación en una localidad de bogotá

Objetivos Establecer la prevalencia y condicionantes asociados al uso de medicamentos por cuenta propia por parte de los habitantes de Suba en Bogotá.Métodos Aplicación de una encuesta pilotada a una muestra aleatoria.  Se midieron variables demográficas y se indagó por problemas de salud relacionados con la automedicación, motivos para no consultar al médico y medicamentos consumidos durante las dos últimas semanasResultados La automedicación fue de 27,3 % (IC 95 %, 19,2 % - 35,3 %) y la autoprescripción de 7,7 % (IC 95%, 2,8 %-12,5 %). La afiliación al Sistema de beneficiarios de la Seguridad Social en Salud (OR=2,61  IC 95 % 1,4-4,8) está asociado con ésta conducta. No se encontró asociación con otras variables. Los medicamentos más consumidos por automedicación son analgésicos (59,3 %), antigripales (13,5 %) y vitaminas (6,8 %).  Los principales problemas por los cuales las personas se automedican son dolor, fiebre y gripa.  Las principales razones que se mencionan para no asistir al médico son falta de tiempo (40 %) y recursos económicos (43 %), además de otros argumentos como la percepción de que el problema es leve y la congestión en los servicios de urgencia.Conclusiones Las cifras de automedicación aunque todavía preocupantes desde el punto de vista de salud pública, son más bajas que las encontradas en estudios similares; los medicamentos consumidos por automedicación pertenecen a la categoría de venta libre y el consumo de antibióticos por automedicación bajó, posiblemente debido a la intensa difusión que se dio a la restricción de venta de antibióticos sin fórmula médica, unos meses antes de la realización de la encuesta

Costos atribuidos a las infecciones asociadas con la atención en salud en un hospital de Colombia, 2011-2015

Introducción. El análisis de los costos derivados de las infecciones asociadas con la atención en salud representa un desafío para el sistema de salud en Colombia dados sus factores determinantes. Objetivo. Determinar los factores relacionados con el aumento y la variabilidad de los costos de la atención hospitalaria por las infecciones asociadas con la atención en salud en un hospital de cuarto nivel de Bogotá, entre el 2011 y el 2015. Materiales y métodos. Se analizaron los costos de la atención de 292 pacientes, los cuales se estimaron para cada una de las actividades realizadas desde el momento de sospechar el cuadro infeccioso hasta su resolución. Dichos costos se estandarizaron según el valor del manual tarifario del Instituto de Seguros Sociales, ajustándolos por el índice de precios al consumidor para salud hasta el año 2014. Se determinaron los factores relacionados con el aumento del costo del manejo mediante un modelo logístico condicional. Resultados. La estancia hospitalaria de nueve días o más antes de la infección, se asoció con el aumento del costo directo del manejo de las infecciones relacionadas con la atención en salud (odds ratio, OR=2,06; IC95% 1,11-3,63). El costo medio del manejo de las infecciones fue de COP $1.190.879. Los antibióticos representaron el 41 % del valor total del tratamiento, seguidos de los exámenes de laboratorio, con un costo equivalente al 13,5 %. Conclusión. Se encontró una relación entre el costo del manejo de las infecciones asociadas con la atención en salud y la estancia hospitalaria previa a su aparición. Los antecedentes patológicos de los pacientes no se relacionaron con el aumento de los costos

Profilaxis de la tromboembolia venosa en pacientes colombianos de tratamiento médico o quirúrgico: resultados para Colombia del estudio ENDORSE

Introduction. More information is needed on the risk of venous thromboembolism in the hospital setting, and on patterns of use of thromboprophylaxis, as advocated in consensus guidelines. ENDORSE was an international study aimed at evaluating hospital venous thromboembolism prevention practices in medical and surgical patientes.Objectives. The risk of venous thromboembolism was evaluated along with the use of thromboprophylaxis in hospitalized medical and surgical subjects; these data were compared with the international sample from the ENDORSE study.Materials and methods. Participating institutions in Colombia were selected arbitrarily. The medical charts for medical and surgical patients were evaluated randomly. The 2004 American College of Chest Physician guidelines were used to evaluate risk of venous thromboembolism and adherence to recommended thromboprophylaxis regimens.Results. The study included 761 subjects (218 surgical, 543 medical) located in five acute care hospitals; 49% of these subjects were considered at risk of venous thromboembolism (40% medical, 72% surgical), compared with 52% in the international sample. Prophylaxis use was higher in medical patients at risk (63.7%, n=137) than in surgical patients (48.4%, n=76; p=0.01). Compared with the international sample, the use of prophylaxis in Colombia was greater in medical patients (63.7% vs. 39.5%, p=0.003), but lower in surgical patients (48.4% vs. 58.5%, p=0.02).Conclusions. Participating Colombian centers treat patients at risk of venous thromboembolism similarly to other participant countries, but appropriate prophylaxis was prescribed more frequently to medical patients. Greater efforts are needed, both in Colombia and around the world, to improve rates of appropriate venous thromboembolism prophylaxis in at-risk subjects.Introducción. La profilaxis en pacientes de tratamiento médico o quirúrgico con riesgo de tromboembolia venosa, requiere ser evaluada para obtener suficiente información que contribuya a mejorar estas prácticas, para que sean efectivas y eficaces, y ayudar con las medidas necesarias de prevención hospitalaria de la tromboembolia venosa.Objetivo. Evaluar el riesgo de tromboembolia venosa y de los hábitos de profilaxis en pacientes de tratamiento médico o quirúrgico hospitalizados en Colombia y compararlos con los de los centros internacionales participantes en el estudio ENDORSE.Materiales y métodos. Las instituciones fueron escogidas al azar. Se evaluaron todas las historias clínicas de pacientes de tratamiento médico o quirúrgico. Se utilizaron las guías del 2004 del American College of Chest Physicians para evaluar el riesgo de tromboembolia venosa y lo apropiado de la profilaxis.Resultados. Se evaluaron 761 pacientes: 218 de tratamiento quirúrgico y 543 de tratamiento médico, de cinco centros hospitalarios de Colombia. De esta población, 49 % se encontraba en riesgo de tromboembolia venosa (40 % de los de tratamiento médico y 72% de los de tratamiento quirúrgico), en comparación con 52 % de la muestra internacional. La profilaxis fue significativamente mayor en los pacientes de tratamiento médico en riesgo (63,7 %, n=137), que en los de tratamiento quirúrgico (48,4 %, n=76, P=0,01). En comparación con la muestra internacional, la profilaxis en los de tratamiento médico fue significativamente superior (63,7 % Vs. 39,5 %, P=0,003), a diferencia de los de tratamiento quirúrgico (48,4 % Vs. 58,5 %, P=0,02).Conclusiones. Los resultados muestran que en los centros hospitalarios de Colombia se trataron pacientes con riesgo de tromboembolia venosa en forma similar al resto de los países participantes en el estudio ENDORSE, y que se hizo más profilaxis apropiada en pacientes de tratamiento médico. Sin embargo, se requiere mejorar la utilización de profilaxis en pacientes hospitalizados

Clinical and economic outcomes associated with malnutrition in hospitalized patients

Background & aims: Hospitalized patients show a high rate of malnutrition, which is associated with poor patient outcomes and high healthcare costs. However, relatively few studies have investigated the association between clinical and economic outcomes and malnutrition in hospitalized patients, particularly those with cardiac and pulmonary conditions. Methods: This multicenter prospective observational cohort study included 800 patients hospitalized at four Colombian hospitals with a diagnosis of congestive heart failure, acute myocardial infarction, community-acquired pneumonia, or chronic obstructive pulmonary disease. All patients were screened for malnutrition using the Malnutrition Screening Tool (MST). A descriptive analysis of baseline variables was followed by multivariate analysis and inverse probability weighting (IPW) to compare the clinical outcomes, i.e., length of stay (LOS), mortality, and readmission, and hospital costs associated with a positive MST result. Results: The prevalence of a positive MST result was 24.62% (n ¼ 197) and was more common in patients with older age and greater comorbidities. Multivariate analysis controlling for age, gender, healthcare plan, university degree, hospitalization, entrance disease and Charlson co-morbidity index showed that a positive MST result was associated with increased LOS (1.43 ± 0.61 days) and both in-hospital mortality (odds ratio, 2.39) and global mortality (odds ratio, 2.52). IPW analysis confirmed the association between a positive MST result and increased hospital LOS and 30-day mortality, as well as a relative increase of 30.13% in the average cost associated with hospitalization. Conclusions: This study of hospital inpatients demonstrated a high burden of malnutrition at the time of hospital admission, which negatively impacted LOS and mortality and increased the costs of hospitalization. These findings underscore the need for improved diagnosis and treatment of hospital malnutrition to improve patient outcomes and reduce healthcare costs

Comparison of the pulmonary function of patients with type 2 diabetes mellitus treated with insulin injections versus that of patients treated with oral hypoglucemic agents

Introducción: la potencial asociación entre el tipo de tratamiento de la diabetes mellitus tipo 2 (DM2) y alteración de la función pulmonar es algo poco estudiado hasta ahora. Objetivos: comparar la función pulmonar de pacientes con DM2 que reciben tratamiento con insulina inyectable versus hipoglicemiantes orceles (HO). Determinar si niveles de marcadores de inflamación en pacientes con tratamiento basado en insulina son diferentes a los de los tratados con HO. Métodos: estudio observational analítico de corte transversal a partir de una muestra de conveniencia de 369 pacientes con diagnóstico de DM2, y tratamiento con insulina o HO. Se realizaron espirometrías, y se obtuvieron valores residuales promedios para VEF1, CVF y relación VEF1/CVF. Mediante regresión lineal múltiple, se ajustó por diferencias en determinantes conocidos de la función pulmonar, así como por control de la diabetes y tiempo desde el diagnóstico. Adicionalmente, se midieron niveles de marcadores inflamatorios sanguíneos para cada grupo de tratamiento. Resultados: 63 pacientes (17%) recibían tratamiento con insulina y 306 (83%) con HO. La diferencia en residuales faxoreció a los tratados con HO. Para VEF1, CVF y VEF1/CVF la diferencia fue 57.6 mL (IC95% 32.45-82.74; P 0.0047), 45.6 mL (IC95% 20.84-70.39; P 0.0231) y 0.017, (IC95% 0.01-0.02, PcO.0001), respectivamente. No hubo cambios estadísticamente significativos en marcadores de inflamación. Conclusiones: los pacientes en tratamiento con HO presentaron mejor función pulmonar que los tratados con insulina. Este hallazgo de diferencias en función pulmonar pudiera tener implicación clínica en el manejo de los pacientes diabéticos, pero debe confirmarse en estudios prospectivos.Artículo original113-118Introduction: the potential association between the type of treatment of type 2 diabetes mellitus (DM2) and impaired lung function is something rarely studied so far. Objectives: to compare the lung function of patients with DM2 who are treated with injectable insulin versus HO. To determine whether levels of inflammatory markers in patients with insulin-based treatment are different from those treated with HO. Methods: an observational, analytical, cross-sectional study from a convenience sample of 369 patients diagnosed with DM2 and treated with insulin or HO. Spirometry was performed, and residual values were averaged for FEV1, FVC and FEV1/FVC ratios. Multiple linear regression results were adjusted by differences in known determinants of lung function, as well as control of diabetes and time since diagnosis. Additionally, we measured blood levels of inflammatory markers for each treatment group. Results: 63 patients (17%) were treated with insulin and 306 (83%) with OH. The difference in residual favored those treated with HO. For FEV1, FVC and FEV1/FVC the difference was 57.6 mL (95% CI 32.45 to 82.74, P 0.0047), 45.6 mL (95% CI 20.84 to 70.39, P 0.0231) and 0.017 (95% CI 0.01 to 0.02, P <0.0001), respectively. There were no statistically significant changes in inflammation markers. Conclusions: patients treated with HO showed better lung function than those treated with insulin. This finding of differences in lung function may have clinical implications in the management of diabetic patients, but needs to be confirmed in prospective studies

Diabetes mellitus type 2 and deterioration of pulmonary function

Introducción: un aspecto poco estudiado de la diabetes mellitus tipo 2 (DM 2), es su posible asociación con alteraciones de la función pulmonar. Estudios recientes han mostrado niveles mayores de marcadores de inflamación sistémica de bajo nivel en pacientes con DM 2, lo que también podría afectar la función pulmonar. El objetivo de este estudio fue determinar si la función pulmonar de personas con DM 2 es diferente de la función pulmonar de un grupo control sin DM. Población y método: se realizó un estudio observacional transversal, comunitario, en diabéticos y en controles sanos, apareados por estratos de edad y sexo. Los controles fueron vecinos de cada diabético, del mismo sexo y grupo de edad, sin DM. La muestra de diabéticos se seleccionó de la población de pacientes que consultan a la Asociación Colombiana de Diabetes (ACD) en Bogotá. Se comprobó el estatus de diabético y de control sano mediante las pruebas de glucemia en ayunas y glucemia poscarga de glucosa. Se realizaron curvas de flujo volumen tanto para los diabéticos como para los controles, y de acuerdo con los valores de referencia obtenido por Hankinson para mexicoamericanos se obtuvieron valores residuales promedios (observado – esperado) para VEF1, CVF y relación VEF1/CVF. Mediante regresión lineal múltiple se ajustó por diferencias en determinantes conocidos de la función pulmonar (edad, sexo, talla, tabaquismo, exposición a humo de leña). Resultados: se estudiaron 262 diabéticos y 262 sujetos sanos. En los diabéticos así como en los controles sanos, la proporción de mujeres fue 51% y el promedio de edad fue de 50 años. Después de ajustar por determinantes conocidos de la función pulmonar, los casos de DM2 tuvieron menor VEF1 (-91 mL, IC95%: -115, -74; P<0.0001), CVF (-212 mL, IC95%: -225, -199; P<0,0001), y mayor relación VEF1/CVF (0.030%, IC95%: 0.027 a 0.034, P<0.0001) que los controles sin DM. Conclusiones: los pacientes con DM2 presentaron menor CVF y VEF1 que personas sin diabetes mellitus, aún después de ajustar por determinantes conocidos de la función pulmonar incluyendo factores de riesgo. Estos hallazgos pueden estar dados por mayores niveles de marcadores de inflamación aguda y crónica de baja intensidad vistos en pacientes con DM2, y por alteraciones de los músculos respiratorios.Artículo original105-110Introduction: potential impairment of lung function in type 2 diabetes mellitus (DM2) patients has been insufficiently studied. Recent studies have shown increased levels of low intensity inflammatory markers in diabetic patients, which may affect pulmonary function. The objective of this study was to determine if lung function of patients with DM2 is different from that of patients without DM. Patients and method: this was a community based observational cross-sectional study in adult patients with DM2, and in age and sex-matched controls without DM2. The base source from which diabetics were selected was that of the Asociacion Colombiana de Diabetes in Bogotá. In all subjects, blood samples were taken for fasting blood glucose and glycosilated hemoglobin levels, and pulmonary function tests were performed. Mean residual values were obtained for FEV1, FVC and VEF1/CVF relation, both for diabetics and for controls, and multiple least squares regression was used to adjust for differences in known determinants of lung function (age, sex, height, smoking history, and wood smoke exposure). Results: data were obtained from 262 diabetics and 262 controls. The proportion of women was 51% and average age was 50 years, both for diabetics and controls. After adjustments with linear regression, diabetics had lower VEF1 (-91 mL, IC95%: -115, -74; P<0.0001), CVF (-212 mL, IC95%: -225, -199; P<0,0001), y higher VEF1/CVF relation (0.030%, IC95%: 0.027 a 0.034, P<0.0001). Conclusions: subjects with DM2 had lower forced vital capacity (FVC) and lower forced expiratory volume in one second (VEF1) than those without DM2, even after adjustment by known determinants of lung function, including risk factors. These findings may be associated with higher levels of inflammation mediators in DM2 patients

Extended-duration venous thromboembolism prophylaxis in acutely ill medical patients with recently reduced mobility : a randomized trial

Q1Q18-18BACKGROUND: Extended-duration low-molecular-weight heparin has been shown to prevent venous thromboembolism (VTE) in high-risk surgical patients. OBJECTIVE: To evaluate the efficacy and safety of extended-duration enoxaparin thromboprophylaxis in acutely ill medical patients. DESIGN: Randomized, parallel, placebo-controlled trial. Randomization was computer-generated. Allocation was centralized. Patients, caregivers, and outcome assessors were blinded to group assignment. (ClinicalTrials.gov registration number: NCT00077753) SETTING: 370 sites in 20 countries across North and South America, Europe, and Asia. PATIENTS: Acutely ill medical patients 40 years or older with recently reduced mobility (bed rest or sedentary without [level 1] or with [level 2] bathroom privileges). Eligibility criteria for patients with level 2 immobility were amended to include only those who had additional VTE risk factors (age >75 years, history of VTE, or active or previous cancer) after interim analyses suggested lower-than-expected VTE rates. INTERVENTION: Enoxaparin, 40 mg/d subcutaneously (2975 patients), or placebo (2988 patients), for 28 +/- 4 days after receiving open-label enoxaparin for an initial 10 +/- 4 days. MEASUREMENTS: Incidence of VTE up to day 28 and of major bleeding events up to 48 hours after the last study treatment dose. RESULTS: Extended-duration enoxaparin reduced VTE incidence compared with placebo (2.5% vs. 4%; absolute risk difference favoring enoxaparin, -1.53% [95.8% CI, -2.54% to -0.52%]). Enoxaparin increased major bleeding events (0.8% vs. 0.3%; absolute risk difference favoring placebo, 0.51% [95% CI, 0.12% to 0.89%]). The benefits of extended-duration enoxaparin seemed to be restricted to women, patients older than 75 years, and those with level 1 immobility. LIMITATION: Estimates of efficacy and safety for the overall trial population are difficult to interpret because of the change in eligibility criteria during the trial. CONCLUSION: Use of extended-duration enoxaparin reduces VTE more than it increases major bleeding events in acutely ill medical patients with level 1 immobility, those older than 75 years, and women. PRIMARY FUNDING SOURCE: Sanofi-aventis

The epidemiology of sepsis in Colombia : a prospective multicenter cohort study in ten university hospitals

Q1Q11675-1682OBJECTIVE: Our aim was to determine the frequency and the clinical and epidemiologic characteristics of sepsis in a hospital-based population in Colombia. DESIGN: Prospective cohort. SETTING: Ten general hospitals in the four main cities of Colombia. PATIENTS: Consecutive patients admitted in emergency rooms, intensive care units, and general wards from September 1, 2007, to February 29, 2008, with confirmation of infection according to the Centers for Disease Control and Prevention definitions. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The following information was recorded: demographic, clinical, and microbiologic characteristics; Acute Physiology and Chronic Health Evaluation II and Sequential Organ Failure Assessment scores; requirement for intensive care unit; length of stay; and 28-day all-cause mortality. During a period of 6 months, 2,681 patients were recruited: 69% and 31% with community-acquired and hospital-acquired infections, respectively. The mean age was 55 yrs (SD = 21), 51% were female, and the median length of stay was 10 days (interquartile range, 5-19). The mean Acute Physiology and Chronic Health Evaluation score was 11.5 (SD = 7) and the mean Sequential Organ Failure Assessment score was 3.8 (SD = 3). A total of 422 patients with community-acquired infections (16%) were admitted to the intensive care unit as a consequence of their infection and the median length of stay was 4.5 days in the intensive care unit. At admission, 2516 patients (94%) met at least one sepsis criterion and 1,658 (62%) met at least one criterion for severe sepsis. Overall, the 28-day mortality rates of patients with infection without sepsis, sepsis without organ dysfunction, severe sepsis without shock, and septic shock were 3%, 7.3%, 21.9%, and 45.6%, respectively. In community-acquired infections, the most frequent diagnosis was urinary tract infection in 28.6% followed by pneumonia in 22.8% and soft tissue infections in 21.8%. Within hospital-acquired infections, pneumonia was the most frequent diagnosis in 26.6% followed by urinary tract infection in 20.4% and soft tissue infections in 17.4%. CONCLUSIONS: In a general inpatient population of Colombia, the rates of severe sepsis and septic shock are higher than those reported in the literature. The observed mortality is higher than the predicted by the Acute Physiology and Chronic Health Evaluation II score