Comportamiento del consumo de oxígeno durante una sesión de rehabilitación cardíaca / Behavior of Oxygen Consumption During a Cardiac Rehabilitation Session

RESUMEN Objetivo: estudiar el comportamiento del consumo de oxígeno en pacientes con miocardiopatía dilatada durante una sesión de rehabilitación cardíaca. Material y métodos: diseño observacional, transversal, analítico relacional. Muestra: 10 pacientes masculinos con miocardiopatía dilatada, con deterioro de moderado a grave de la función ventricular. Se evaluó a los pacientes en laboratorio y en una sesión de rehabilitación mediante un analizador de gases portátil Medgraphics® VO 2000. La sesión de rehabilitación consistió en ejercicios en bicicleta fija de 10 minutos, step, escalera coordinativa, fuerza con mancuerna para bíceps y hombros, cuádriceps en camilla y dorsales en máquina. Resultados: Edad (años) 57,4 ± 14,6. Peso (kg) 91,4 ± 22,2. Talla (cm) 168,1 ± 6,2. Laboratorio: VO2max relativo (ml/kg/min) 21,8 ± 7,3. Tasa de intercambio respiratorio, RER (VCO2/VO2)1,05 ± 0,09. Volumen ventilado (L/min) 65,7 ± 18,5. Frecuencia cardíaca (lat./min) en VO2max 127,8 ± 23,8. Sesión: Duración (min) 37,5 ± 10. VO2pico (ml/kg/min) 14,6 ± 3 (69,9 ± 16,7% del VO2max). Coeficiente de correlación entre VO2max y tiempo con VO2 < 50% del VO2max (min) 0,662 (p = 0,037) y entre VO2pico en rehabilitación y tiempo en RER entre 0,85-1(min) 0,787 (p = 0,007). Los pacientes con mejor aptitud ejercitaron en zona de baja intensidad. Al aumentar el esfuerzo, aumentaron los minutos en intensidad moderada. Conclusión: Se constató en este estudio que los pacientes alcanzaron un VO2pico en las sesiones inferiores a sus máximos obtenidos en laboratorio. Si bien cualquier dosis de entrenamiento en estos pacientes es más beneficiosa que la inactividad física, el diseño y la planificación de las sesiones de RHC, valorando las intensidades de trabajo intrasesión, podrían generar mayor impacto en la mortalidad, las reinternaciones y en la calidad de vida.

ABSTRACT Objective: The aim of this study was to analyze the response of oxygen consumption in patients with dilated cardiomyopathy during a cardiac rehabilitation session. Methods: This was an observational, cross-sectional, relational analytical study. Ten male patients with dilated cardiomyopathy and moderate to severe ventricular dysfunction were included in the study. Patients were evaluated in the laboratory and during a rehabilitation session using a Medgraphics VO 2000 portable gas analyzer. The rehabilitation session consisted in 10 minutes of stationary bike exercises, step, coordinaton stairs, and muscle strength using dumbbells for biceps and shoulder, a quadriceps stretcher and a dorsal muscle machine. Results: Mean age was 57.4 ± 14.6 years, weight 91.4 ± 22.2 kg and height 168.1 ± 6.2 cm. In the laboratory, VO2max was 21.8 ± 7.3 ml/kg/min, respiratory exchange rate (RER) (VCO2/VO2) 1.05 ± 0.09, ventilated volume 65.7 ± 18.5 L/min and heart rate in VO2max 127.8 ± 23.8 beats/min. Rehabilitation session duration was 37.5 ± 10 min with peakVO2 14.6 ± 3 ml kg/min (69.9 ± 16.7 % VO2max). The correlation coefficient between VO2max and time with VO2 <50% VO2max(min) was 0.662 (p = 0.037) and between peakVO2 in rehabilitation and time in RER between 0.85-1 (min) was 0.787 (p = 0.007). Patients with better fitness exercised in the low-intensity zone. As exercise increased, the minutes in moderate intensity also increased. Conclusion: The study showed that patients reached peakVO2 in sessions below the maximum values obtained in the laboratory. Even though any dose of training in these patients was more beneficial than physical inactivity, cardiac rehabilitation session design and planning, taking into account intrasession exercise intensities, could generate greater impact on mortality, rehospitalizations and quality of life.

El peso transportado en las mochilas escolares: Un estudio en cuatro escuelas de la región metropolitana de Buenos Aires, Argentina / A study concerning how much weight schoolchildren carry in their bags, involving four schools in the metropolitan area of Buenos Aires, Argentina

RESUMEN Objetivo Determinar el peso transportado del equipaje escolar (en valores absolutos y relativos) y la distancia caminada en los trayectos hogar-escuela, en escolares de cuatro escuelas de la región metropolitana de Buenos Aires. Métodos Se estudiaron 751 alumnos (394 varones y 357 mujeres, de 9 a 18 años) de niveles primario (4to. a 6to. grados), y secundario (1ro. a 3er. años) de tres escuelas de gestión privada y una pública. Se midieron los pesos corporal y del equipaje escolar, y se indagó sobre la distancia desde la escuela al hogar, y sobre las cuadras caminadas en este trayecto. Se realizó un análisis descriptivo y contrastes según género, nivel educativo, tipo de escuela y grados y años cursados. Se verificaron posibles asociaciones entre variables. Se dividió al grupo en dos: quienes transportaban menos del 10 % de su peso corporal, y los que acarreaban el 10 % (considerado como valor crítico) y más, calculándose las frecuencias según tipo de equipaje utilizado. Resultados El 68 % de los evaluados transporta un peso por encima del 10 % del peso corporal (P42=10,13 %), siendo del 66 % para varones (P44 = 10,12 %) y 60 % para mujeres (P40=10,2 %). En escuelas privadas se acarrearon mayores pesos que en públicas (p<0,05); y en ambos niveles educativos los alumnos de cursos inferiores transportaron pesos superiores que los de grados superiores (p<0,05). Conclusiones La mayoría de los alumnos transporta pesos relativos por encima de las recomendaciones, siendo las mujeres las más perjudicadas. Los más pequeños cargan pesos absolutos y relativos mayores.

ABSTRACT Objective Determining the weight children carry in their bags to school (absolute and relative values) and the distance walked during home-school routes, involving students from four schools in the metropolitan area of Buenos Aires. Method The study involved 751 primary (4th to 6th grades) and secondary (1st to 3rd years) level students who were attending three private schools and one public one. Body and bag weights were measured and the children were asked about the distance (in blocks) they walked from school to home. The study involved a descriptive analysis and contrasted the students by gender, educational level, type of school and grade or year. Possible associations between variables were ascertained. The group was divided into those carrying bags weighing less than 10% of their body weight and those who carrying 10% (considered a critical value) and more; frequencies were calculated by the type of bag being used. Results 68% of the sample were carrying 10% or more of their body weight (P42=10.13%): 66% in male (P44=10.12%) and 60% in female children (P40=10.2%). Private school students carried more weight than public school children (p<0.05) and younger students carried a greater weight than older students (p<0.05) in both educational levels. Conclusions Most children were carrying relative weights well above that recommended and female students were most affected. Younger students carried higher absolute and relative weights.

[A study concerning how much weight schoolchildren carry in their bags, involving four schools in the metropolitan area of Buenos Aires, Argentina]. / El peso transportado en las mochilas escolares: Un estudio en cuatro escuelas de la región metropolitana de Buenos Aires, Argentina

OBJECTIVE: Determining the weight children carry in their bags to school (absolute and relative values) and the distance walked during home-school routes, involving students from four schools in the metropolitan area of Buenos Aires. METHOD: The study involved 751 primary (4th to 6th grades) and secondary (1st to 3rd years) level students who were attending three private schools and one public one. Body and bag weights were measured and the children were asked about the distance (in blocks) they walked from school to home. The study involved a descriptive analysis and contrasted the students by gender, educational level, type of school and grade or year. Possible associations between variables were ascertained. The group was divided into those carrying bags weighing less than 10% of their body weight and those who carrying 10% (considered a critical value) and more; frequencies were calculated by the type of bag being used. RESULTS: 68% of the sample were carrying 10% or more of their body weight (P42=10.13%): 66% in male (P44=10.12%) and 60% in female children (P40=10.2%). Private school students carried more weight than public school children (p<0.05) and younger students carried a greater weight than older students (p<0.05) in both educational levels. CONCLUSIONS: Most children were carrying relative weights well above that recommended and female students were most affected. Younger students carried higher absolute and relative weights.