Impact of High-Flow Nasal Cannula Use in Subjects With COVID-19 ARDS at High Altitudes: Clinical Presentation and Prognostic Factors.

BACKGROUND: High-flow nasal cannula (HFNC) reduces the need for intubation in adult subject with acute respiratory failure. Changes in hypobaric hypoxemia have not been studied for subject with an HFNC in ICUs at altitudes > 2,600 m above sea level. In this study, we investigated the efficacy of HFNC treatment in subjects with COVID-19 at high altitudes. We hypothesized that progressive hypoxemia and the increase in breathing frequency associated with COVID-19 in high altitudes affect the success of HFNC therapy and may also influence the performance of the traditionally used predictors of success and failure. METHODS: This was a prospective cohort study of subjects >18 y with a confirmed diagnosis of COVID-19-induced ARDS requiring HFNC who were admitted to the ICU. Subjects were followed up during the 28 d of HFNC treatment or until failure. RESULTS: One hundred and eight subjects were enrolled. At admission to the ICU, FIO2 delivery between 0.5-0.8 (odds ratio 0.38 [95% CI 0.17-0.84]) was associated with a better response to HFNC therapy than oxygen delivery on admission between 0.8-1.0 (odds ratio 3.58 [95% CI 1.56-8.22]). This relationship continued during follow-ups at 2, 6, 12, and 24 h, with a progressive increase in the risk of failure (odds ratio 24 h 13.99 [95% CI 4.32-45.26]). A new cutoff for the ratio of oxygen saturation (ROX) index (ROX ≥ 4.88) after 24 h of HFNC administration was demonstrated to be the best predictor of success (odds ratio 11.0 [95% CI 3.3-47.0]). CONCLUSIONS: High-altitude subjects treated with HFNC for COVID-19 showed a high risk of respiratory failure and progressive hypoxemia when FIO2 requirements were > 0.8 after 24 h of treatment. In these subjects, personalized management should include continuous monitoring of individual clinical conditions (such as oxygenation indices, with cutoffs adapted to those corresponding to high-altitude cities).

The ultrasound-based cardiac output monitoring is a useful tool to define baseline hemodynamic parameters in healthy permanent residents at high altitude: results of a monocentric pilot study.

Previous studies on the cardiac data of healthy permanent residents living in high-altitude regions such as Tibet and the Andes have yielded inconsistent findings and significant disparities. These discrepancies can be mainly attributed to the invasive methods conventionally used for parameter evaluation. However, with the introduction of cutting-edge ultrasound technology, there is now an innovative approach to addressing and reconciling these variations. In this pilot study, we employed an ultrasound-based cardiac output monitoring (USCOM) device to evaluate cardiac output and related hemodynamic variables in a group of 20 healthy high-altitude Andean residents (comprising 10 men and 10 women) aged between 26 and 35 years old. The monocentric study was carried out in La Paz, Bolivia, located between at an altitude of 3,600-4,000 m. A total of 60 hemodynamic measurements were evaluated, accounting for three technical replicates per subject. Our results showed strong intrasubject reproducibility and revealed important differences related to both sex and hemodynamic parameters in highlanders compared to individuals residing at sea level. We conclude that USCOM represents a highly reliable technology for performing hemodynamic measurements in high-altitude residents. Our preliminary findings underscore the need for larger studies, encompassing larger sample sizes, specifically tailored to gender considerations, and extendable to broader highland populations. These findings have special significant implications for the management of hemodynamics in intensive care and postoperative settings, warranting further comprehensive research efforts.

Acoustic emissions of Sorex unguiculatus (Mammalia: Soricidae): Assessing the echo-based orientation hypothesis.

Shrew species have been proposed to utilize an echo-based orientation system to obtain additional acoustic information while surveying their environments. This system has been supported by changes in vocal emission rates when shrews encounter different habitats of varying complexity, although detailed acoustic features in this system have not been reported. In this study, behavioral experiments were conducted using the long-clawed shrew (Sorex unguiculatus) to assess this orientation system. Three experimental conditions were set, two of which contained obstacles. Short-click, noisy, and different types of tonal calls in the audible-to-ultrasonic frequency range were recorded under all experimental conditions. The results indicated that shrews emit calls more frequently when they are facing obstacles or exploring the experimental environment. Shrews emitted clicks and several different types of tonal calls while exploring, and modified the use of different types of calls for varying behavior. Furthermore, shrews modified the dominant frequency and duration of squeak calls for different types of obstacles, that is, plants and acrylic barriers. The vocalizations emitted at short inter-pulse intervals could not be observed when shrews approached these obstacles. These results are consistent with the echo-based orientation hypothesis according to which shrews use a simple echo-orientation system to obtain information from their surrounding environments, although further studies are needed to confirm this hypothesis.

Actividad física y composición corporal en estudiantes universitarios de cultura física, deporte y recreación / Physical activity and body composition among college students of physical culture, sport and recreation

Introducción: La actividad física es un factor determinante de la salud relacionado con el estilo de vida y su práctica regular está asociada con disminución de enfermedades crónicas. Objetivos: Describir la cantidad de actividad física en los diferentes dominios (ocupacional, desplazamiento y tiempo libre), y establecer el índice de masa corporal y el porcentaje de grasa corporal de los estudiantes. Metodología: Estudio analítico, corte transversal realizado en estudiantes de pregrado de una facultad de cultura física, deporte y recreación. La actividad física fue determinada mediante Cuestionario Mundial de Actividad Física. Se evaluó la actividad física en los dominios ocupacional, desplazamiento y tiempo libre. Resultados: El 21.0% presentó sobrepeso y 3.6% obesidad, según índice de masa corporal. El 12.6% presentó exceso de grasa total corporal. El 98.8% de los estudiantes es activo físicamente y cumple con las recomendaciones de la Organización Mundial de la Salud sobre actividad física para la salud. El análisis estratificado del exceso de peso, actividad física y conducta sedentaria por semestre académico, evidencia mayor porcentaje sobrepeso u obesidad en los estudiantes que cursaban de sexto a décimo semestre. Conclusiones: La mayoría de estudiantes analizados son físicamente activos. Los estudiantes que se encontraban cursando la segunda mitad de la carrera presentan mayores porcentajes de exceso de peso. Evaluar el nivel de actividad física en estudiantes de cultura física resulta importante dado que representan un grupo de futuros profesionales enfocados hacia la promoción de estilos de vida saludables relacionados con adecuados niveles de actividad física.

Introduction: Physical activity is an important determinant of health-related lifestyle and its regular practice is associated with reduction of chronic diseases. Objectives: To describe the amount of physical activity in different domains (occupational, displacement and free time), and assess the Body Mass Index and body fat percentage of students. Methodology: An analytic, cross-sectional study was carried out in college students of a faculty of physical culture, sport and recreation. Physical activity was determined by Global Physical Activity Questionnaire. Physical activity in the occupational, displacement and free time domains, was assessed. Results: The prevalence of overweight was 21.0% andof obesity 3.6% according to body mass index. 12.6% had excess total body fat. 98.8% of students were physically active and comply with the recommendations of the World Health Organization on physical activity for health. Stratified analysis of excess weight, physical activity and sedentary behavior by semester, evidenced higher percentage overweight or obesity in sixth to tenth semester students than those from first to fifth semester. Conclusions: Most students analyzed were physically active. Students who were enrolled in the second half of the race had higher percentages of excess weight. To assess the level of physical activity in students of physical culture is important because they represent a group of future professionals focused on promoting healthy lifestyles related to adequate levels of physical activity.