¿Sobreestimamos las necesidades de líquidos? Complicaciones del uso de sueros isotónicos de mantenimiento en plantas de hospitalización pediátrica / Do we overestimate intravenous fluid therapy needs? Adverse effects related to isotonic solutions during paediatric hospital admissions

Introducción: La fluidoterapia intravenosa es un tratamiento ampliamente utilizado en pacientes pediátricos hospitalizados. El objetivo del estudio fue analizar las complicaciones asociadas al uso de sueros isotónicos de mantenimiento en pacientes hospitalizados y comparar la frecuencia de aparición de estas complicaciones con distintos ritmos de administración. Materiales y métodos: Se realizó un estudio observacional y prospectivo, en el que se incluyeron pacientes hospitalizados de entre tres meses y 15 años de edad que recibieron tratamiento con fluidoterapia isotónica 0,9% con glucosa al 5% durante las primeras 24 horas de ingreso. Se dividieron en dos cohortes según el ritmo de fluidoterapia: restringido<100% vs. no restringido cercano al 100% necesidades basales (NNBB), calculadas según la regla de Holliday y Segar. Se recogieron variables clínicas y analíticas en dos tiempos de estudio (T0 al ingreso y T1 a las 24 horas de la fluidoterapia). Se realizó un estudio uni y multivariante para identificar factores de riesgo de complicaciones. Resultados: Se incluyeron 84 pacientes, de los cuales 33 recibieron fluidoterapia restringida y 51 pacientes con 100% NNBB. Las principales complicaciones desarrolladas en las primeras 24 horas fueron hipercloremia> 110 mEq/L (16,6%) y edemas (19%). La aparición de edemas fue más frecuente en pacientes de menor edad (p <0,01) y la hipercloremia se asoció con el desarrollo de edemas (OR 1,73 [1,0-3,8]), p=0,06. Conclusiones: La administración de sueros isotónicos no está exenta de complicaciones, probablemente relacionadas con el ritmo de administración y más frecuentes en lactantes. Son necesarios estudios que revisen las necesidades de líquidos en niños hospitalizados. (AU)

Introduction: Maintenance intravenous fluids are frequently used in hospitalised paediatric patients. The aim of the study was to describe the adverse effects of isotonic fluid therapy in hospitalised patients, and its prevalence based on the rate of infusion. Materials and methods: A prospective clinical observational study was designed. We included hospitalised patients between 3 months-old and 15-years-old were included with 0.9% isotonic solutions with 5% glucose within the first 24h of administration. They were divided into two groups, depending on the quantity of liquid they received (restricted<100% vs. 100% maintenance needs). Clinical data and laboratory findings were recorded in two different times (T0 when they were admitted to hospital and T1 within the first 24h of administration). Results: The study included 84 patients, 33 received <100% maintenance needs and 51 patients received around 100%. The main adverse effects notified in the first 24h of administration were hyperchloremia>110mEq/L (16.6%) and oedema (19%). Oedema was more frequent in patients with lower age (p<0.01). The hyperchloremia at 24h of intravenous fluids was an independent risk factor of developing oedema (OR 1.73 [1.0–3.8], p=0.06). Conclusions: The use of isotonic fluids is not free from adverse effects, probably related to the rate of infusion and more likely to appear in infants. It is necessary more studies that review the correct estimation of intravenous fluid needs in hospitalised children. (AU)

Do we overestimate intravenous fluid therapy needs? Adverse effects related to isotonic solutions during pediatric hospital admissions.

INTRODUCTION: Maintenance intravenous fluids are frequently used in hospitalised pediatric patients. The aim of the study was to describe the adverse effects of isotonic fluid therapy in hospitalised patients, and its prevalence based on the rate of infusion. MATERIALS AND METHODS: A prospective clinical observational study was designed. We included hospitalised patients between 3 months-old and 15-years-old were included with 0,9% isotonic solutions with 5% glucose within the first 24 h of administration. They were divided into two groups, depending on the quantity of liquid they received (restricted <100% vs 100% maintenance needs). Clinical data and laboratory findings were recorded in two different times (T0 when they were admitted to hospital and T1 within the first 24 h of administration). RESULTS: The study included 84 patients, 33 received <100% maintenance needs and 51 patients received around 100%. The main adverse effects notified in the first 24 h of administration were hyperchloremia >110 mEq/L (16.6%) and oedema (19%). Oedema was more frequent in patients with lower age (p < 0,01). The hyperchloremia at 24 h of intravenous fluids was an independent risk factor of developing oedema (OR 1,73 (1,0-3,8), p = 0,06). CONCLUSION: The use of isotonic fluids is not free from adverse effects, probably related to the rate of infusion and more likely to appear in infants. It`s necessary more studies that review the correct estimation of intravenous fluid needs in hospitalized children.

Delayed onset muscle soreness intensity affects muscular performance / El Dolor muscular de aparición tardía afecta el desempeño muscular

Abstract Background: The study of functional impact of delayed onset muscle soreness has been limited to describe the decline on maximal isometric contraction, but muscular work and time to peak torque has not been examined yet. Purpose: To describe the changes induced by a session of lengthening contractions on muscle performance and delayed onset muscle soreness (DOMS). Methods: A quasi-experimental study was conducted in the Institutional laboratory; Twenty healthy men; mean age 21 SD 0.34 were recruited, all subjects performed 200 lengthening contractions of the quadriceps at 120°/s. Isometric and isokinetic peak torque, muscular work, time to peak torque, DOMS and creatine kinase activity were assessed at baseline, 48 h and 96 h post-exercise. The muscle performance was assessed with an isokinetic dynamometer and DOMS with a visual analog scale (VAS). Results: Relative to baseline, isometric and isokinetic peak torque and muscular work decreased in ~30% at 48 h post-exercise; delayed onset muscle soreness increased ~300%, which remained at 96 h post-exercise. Conclusions: These reflect that the decline in muscular performance is due to the changes in peak torque and muscular work, which has greater implications on muscle function. No changes were detected in time to peak torque. The alterations in muscular performance variables are accompanied by delayed onset muscle soreness which has also a negative impact on force production (29% of the drop on peak torque is explain by soreness intensity).

Resumen Introducción: Los estudios de impacto funcional del dolor muscular de aparición tardía (DMAT) se han limitado a describir la disminución de la contracción isométrica máxima, pero aún no se ha examinado el trabajo muscular y el tiempo del torque máximo. Objetivo: Describir los cambios inducidos por una sesión de ejercicio excéntrico sobre el rendimiento muscular y DMAT. Método: se realizó un estudio cuasi-experimental, los participantes fueron veinte hombres sanos; edad media 21 DE 0,34, todos los sujetos realizaron 200 contracciones excéntricas del cuádriceps a 120°/s. Se evaluó el torque pico isométrico e isocinético, el trabajo muscular, el tiempo hasta el torque máximo, DMAT y la actividad de la creatina quinasa al inicio, 48 h y 96 h después del ejercicio, el rendimiento muscular se evaluó con un dinamómetro isocinético y DOMS con una escala análoga visual (EAV). Resultados: en relación con la línea de base, el torque pico isométrico e isocinético y el trabajo muscular disminuyeron en ~ 30 % a las 48 h post-ejercicio; El dolor muscular de aparición tardía aumentó ~300 %, que permaneció 96 h después del ejercicio. Conclusiones: los resultados reflejan que la disminución del rendimiento muscular se debe a los cambios en el torque pico y trabajo muscular, lo que tiene mayores implicaciones en la función muscular. No se detectaron cambios en el tiempo hasta el torque máximo. Las alteraciones en las variables de rendimiento muscular se acompañan de DMAT que también tiene un impacto negativo en la producción de fuerza (el 29 % de la caída en el torque máximo se explica por la intensidad del dolor).

Cytotoxicity of solutions recommended for the storage of avulsed teeth in cultures with periodontal ligament cells. / Citotoxicidad de soluciones recomendadas para el almacenamiento de dientes avulsionados en cultivo con células del ligamento periodontal.

Introduction: The medium for avulsed teeth storage until their reimplantation is key to the preservation of human periodontal ligament fibroblasts (HPLF). Objective: Our purpose was to compare the cytotoxic effect of milk and isotonic solution, used for the storage of avulsed teeth, on the preservation of HPLF. Method: A subculture of periodontal ligament fibroblasts was carried out with a density of 1:2 (3 ×105 cells/mL) and was incubated for 48 hours. The cells were divided in two groups, which were placed either in milk or isotonic solution for 24 hours at 5% CO2, 37 ºC and 95% humidity. The number of viable cells was determined with a colorimetric fast assay by the reduction of MTT and mitochondrial activity. Data were processed with the Shapiro-Wilk normality test, Student's t-test and paired Student's t-test (with significance set at 0.05). Results: The cells exposed to milk for 24 hours showed statistically significant cytotoxicity at concentrations of 0.09, 0.39, 0.78, 1.56, 3.125, 6.25 and 50%. HPLFs exposed to isotonic solution showed no significant reduction in the number of cells at concentrations of 25 and 50%. Conclusion: Isotonic solution appears to be better for HPLF 24-hour storage in comparison with whole milk.

Introducción: El medio de almacenamiento de los dientes avulsionados hasta su reimplante es vital para conservar los fibroblastos del ligamento periodontal humano (HPLF). Objetivo: Comparar el efecto citotóxico para conservar los HPLF de la leche y la solución isotónica para almacenamiento de dientes avulsionados. Método: Se realizó subcultivo de fibroblastos del ligamento periodontal con una densidad de 1:2 (3 × 105 células/mL), que fueron incubados por 48 horas. Se integraron dos grupos de células, que se colocaron en leche y solución isotónica durante 24 horas a 5 % de CO2, a 37°C y 95 % de humedad. El número de células viables fue determinado por colorimetría rápida por reducción de MTT y actividad mitocondrial. Los datos fueron sometidos a pruebas de normalidad de Shapiro-Wilk, t de Student y t de Student pareada (significación de 0.05). Resultados: Las células expuestas a la leche por 24 horas mostraron citotoxicidad estadísticamente significativa a concentraciones de 0.09, 0.39, 0.78, 1.56, 3.125, 6.25 y 50 %. Los HPLF expuestos a solución isotónica no mostraron reducción significativa del número de células a concentraciones de 25 y 50 %. Conclusión: La solución isotónica parece mejor para el almacenamiento de HPLF en 24 horas, comparada con la leche entera.

Comparación entre hidratación con leche chocolatada descremada y bebida deportiva posterior al ejercicio físico en militares / Comparison between hydration with chocolate skim milk and sports drink after physical exercise in militaries

Introducción: dos factores importantes han sido descritos como contribuyentes en la aparición de fatiga durante el ejercicio físico: la disminución de las reservas de glucógeno muscular y la pérdida de agua con electrolitos a través del sudor, que favorecen la deshidratación. Debido a esto, la reposición de líquidos y electrolitos posterior al ejercicio físico se transforma en la prioridad para restablecer la homeostasis corporal alterada durante el ejercicio físico. Por su composición nutricional, la leche parece ser una buena alternativa natural como bebida rehidratante posterior al ejercicio físico. Objetivo: comparar la efectividad como bebida de rehidratación de la leche descremada chocolatada contra una bebida deportiva artificial en militares, a partir de la hipótesis de que la leche descremada chocolatada tiene iguales o mejores efectos sobre la hidratación post ejercicio, que una bebida deportiva artificial. Método: 30 militares (23,0 ± 3,2 años) se dividieron en 2 grupos: 1) rehidratación con bebida deportiva con 6 pòr ciento de carbohidratos y relación de Na/K 2:1 (grupo ISO). Rehidratación con leche descremada chocolatada (grupo LECHE). Se evaluó la retención de fluidos a través del peso corporal y la gravedad específica de la orina (GEO) antes y después del ejercicio físico y posterior a las 2 horas de rehidratación. Resultados: se encontraron diferencias significativas (p< 0,05) en la retención de fluidos en el grupo LECHE comparado con el grupo ISO. No hubo diferencias significativas entre la GEO de ambos grupos. Conclusión: Los resultados muestran que la rehidratación con leche descremada es más efectiva en la retención de fluidos y recuperación del peso previo al ejercicio que la bebida deportiva(AU)

ntroduction: Two important factors have been described as contributing to the onset of fatigue during physical exercise: Decreased muscle glycogen stores and the loss of water with electrolytes through sweating, favoring dehydration. Because of this, fluid and electrolyte replacement after physical exercise becomes the priority to restore altered body homeostasis during physical exercise. Due to its nutritional composition, milk appears to be a good natural alternative as a rehydration beverage after exercise. Objective: To compare the effectiveness chocolate skim milk as pots-exercise rehydration beverage with an artificial sports drink in the military, based on the hypothesis that chocolate skim milk has equal or better effects on post-exercise hydration than an artificial sports drink. Method: 30 soldiers (23.0 ± 3.2 years) were divided into 2 groups: 1) rehydration with sports drink with 6 percent carbohydrates and ratio of Na / K 2: 1 (ISO group). Rehydration with chocolate skim milk (LECHE group). Fluid retention was assessed through body weight and the specific gravity of urine (GEO) before and after physical exercise and after 2 hours of rehydration. Results: significant differences were found (p < 0.05) in fluid retention in the LECHE group compared to the ISO group. There were no significant differences between the GEO of both groups. Conclusion: The results show that rehydration with skim milk is more effective in fluid retention and weight recovery prior to exercise than sports drink(AU)

Acute effect of different stretching methods on the strength performance in successive series / Efeito agudo de diferentes métodos de alongamento sobre o desempenho da força em séries sucessivas

ABSTRACT There is still no consensus about the use of stretching before strength exercises in successive series. Thus, the aim was to verify the acute effect of two stretching methods on the strength performance in the bench press exercise. Trained subjects performed 3 sets of 8 to10-RM in the bench press immediately after the static stretching (SS), Proprioceptive Neuromuscular Facilitation (PNF) or control condition. There was a significant decrease in repetitions in the second and third series compared to the first for all conditions. There was no significant difference in the number of repetitions or total volume between the conditions with and without stretching. The SS and PNF induced no negative effect on strength performance and can be used prior to this exercise

RESUMO Ainda não há consenso sobre a utilização de alongamentos antes de exercícios de força em séries sucessivas. Sendo assim, o objetivo foi verificar o efeito agudo de dois métodos de alongamento sobre o desempenho da força no exercício supino reto. Indivíduos treinados realizaram 3 séries de 8 a 10-RM no supino reto imediatamente após o alongamento estático (AE), Facilitação Neuromuscular Proprioceptiva (FNP) ou condição controle. Foi encontrada queda significativa das repetições na segunda e terceira séries em comparação à primeira em todas as condições. Não houve diferença significativa no número de repetições ou no volume total entre as condições com e sem alongamento. O AE e a FNP não causaram impacto negativo no desempenho da força, podendo, assim, serem utilizados previamente a esse exercício.

Ensayo clínico aleatorizado sobre la administración de una solución de mantenimiento intravenosa hipotónica comparada contra una isotónica en pacientes pediátricos críticos / Hypotonic versus isotonic maintenance fluids in critically ill pediatric patients: a randomized control trial

Introducción. Las soluciones hipotónicas se han vinculado a la producción de hiponatremia iatrogénica. Objetivos. Evaluar las variaciones en el sodio sérico (NaS) tras la administración de una solución de mantenimiento intravenosa isotónica (NaCl al 0,9% en dextrosa al 5%) en comparación con una solución de mantenimiento hipotónica (NaCl al 0,45% en dextrosa al 5%). Material y métodos. Ensayo clínico aleatorizado, doble ciego y controlado. Se enrolaron pacientes pediátricos con una estadía esperada en la unidad de cuidados intensivos mayor de 24 horas, NaS normal y líquidos intravenosos > 80% de los líquidos totales de mantenimiento. La concentración sérica de Na se midió antes de colocar la solución de mantenimiento y al reducir la administración de ésta a < 80% del total del aporte. Resultados. Se incorporaron 63 pacientes, que fueron asignados en forma aleatoria a recibir una solución de mantenimiento hipotónica (n= 32) o isotónica (n= 31). Las características basales fueron similares en ambos grupos. No hubo diferencias con respecto a la cantidad de solución administrada (grupo hipotónico 865 ± 853 ml; grupo isotónico 778 ± 649 ml, p= 0,654) o el tiempo de infusión (grupo hipotónico: 24 ± 10,8 horas; grupo isotónico: 27,6 ± 12,8 horas, p= 0,231). Se encontró una diferencia en el NaS luego de la administración de las soluciones de mantenimiento (grupo hipotónico: 137,8 ± 4,3 mmol/L; grupo isotónico: 140,0 ± 4,1 mmol/L, p=0,04). Ninguna de las dos soluciones de mantenimiento aumentó el riesgo de hiponatremia (Na < 135 mmol/L) o de hipernatremia (Na > 145 mmol/L). Conclusiones. Ambas soluciones de mantenimiento, en 24 horas de infusión, no aumentaron el riesgo de producir hiponatremia iatrogénica.

Introduction: Hypotonic fluids have been associated with the development of iatrogenic hyponatremia. Objectives. To assess variations in serum sodium (sNa) following the intravenous administration of isotonic maintenance fluids (0.9% NaCl/5% dextrose) compared to hypotonic maintenance fluids (0.45% NaCl/5% dextrose). Material and Methods. Randomized, controlled, double-blind clinical trial. Pediatric patients with an expected length of stay in the intensive care unit of more than 24 hours were enrolled, with normal serum Na, and IV fluids >80% of total maintenance fluids. Serum Na level was measured before administering maintenance fluids and when reducing the administration to <80% of total fluids. Results. The study included 63 patients who were randomly assigned to receive hypotonic (n= 32) or isotonic (n= 31) maintenance fluids. Baseline characteristics were similar inboth groups. There were no differences in terms of volume of fluid administered (hypotonic group: 865 ± 853 mL; isotonic group: 778 ± 649 mL; p=0.654) or infusion duration (hypotonic group: 24 ± 10.8 hours; isotonic group: 27.6 ± 12.8 hours; p= 0.231). A difference was found in the serum Na following the administration of maintenance fluids (hypotonic group: 137.8 ± 4.3 mmol/L; isotonic group: 140.0 ±4.1 mmol/L, p= 0.04). None of these two maintenance fluids increased the risk of hyponatremia (Na <135 mmol/L) or hypernatremia (Na >145 mmol/L). Conclusions. Neither hypotonic nor isotonic maintenance fluids increased the risk of developing iatrogenic hyponatremia with the 24 hour infusion.

Ensayo clínico aleatorizado sobre la administración de una solución de mantenimiento intravenosa hipotónica comparada contra una isotónica en pacientes pediátricos críticos: a randomized control trial / Hypotonic versus isotonic maintenance fuids in critically ill pediatric patients

Introducción. Las soluciones hipotónicas se han vinculado a la producción de hiponatremia iatrogénica. Objetivos. Evaluar las variaciones en el sodio sérico (NaS) tras la administración de una solución de mantenimiento intravenosa isotónica (NaCl al 0,9% en dextrosa al 5%) en comparación con una solución de mantenimiento hipotónica (NaCl al 0,45% en dextrosa al 5%). Material y métodos. Ensayo clínico aleatorizado, doble ciego y controlado. Se enrolaron pacientes pediátricos con una estadía esperada en la unidad de cuidados intensivos mayor de 24 horas, NaS normal y líquidos intravenosos > 80% de los líquidos totales de mantenimiento. La concentración sérica de Na se midió antes de colocar la solución de mantenimiento y al reducir la administración de ésta a < 80% del total del aporte. Resultados. Se incorporaron 63 pacientes, que fueron asignados en forma aleatoria a recibir una solución de mantenimiento hipotónica (n= 32) o isotónica (n= 31). Las características basales fueron similares en ambos grupos. No hubo diferencias con respecto a la cantidad de solución administrada (grupo hipotónico 865 ± 853 ml; grupo isotónico 778 ± 649 ml, p= 0,654) o el tiempo de infusión (grupo hipotónico: 24 ± 10,8 horas; grupo isotónico: 27,6 ± 12,8 horas, p= 0,231). Se encontró una diferencia en el NaS luego de la administración de las soluciones de mantenimiento (grupo hipotónico: 137,8 ± 4,3 mmol/L; grupo isotónico: 140,0 ± 4,1 mmol/L, p= 0,04). Ninguna de las dos soluciones de mantenimiento aumentó el riesgo de hiponatremia (Na 145 mmol/L). Conclusiones. Ambas soluciones de mantenimiento, en 24 horas de infusión, no aumentaron el riesgo de producir hiponatremia iatrogénica.

Introduction. Hypotonic fluids have been associated with the development of iatrogenic hyponatremia. Objectives. To assess variations in serum sodium (sNa) following the intravenous administration of isotonic maintenance fuids (0.9% NaCl/5% dextrose) compared to hypotonic maintenance fuids (0.45% NaCl/5% dextrose). Material and Methods. Randomized, controlled, double-blind clinical trial. Pediatric patients with an expected length of stay in the intensive care unit of more than 24 hours were enrolled, with normal serum Na, and IV fuids >80% of total maintenance fuids. Serum Na level was measured before administering maintenance fuids and when reducing the administration to <80% of total fuids. Results. The study included 63 patients who were randomly assigned to receive hypotonic (n= 32) or isotonic (n= 31) maintenance fuids. Baseline characteristics were similar in both groups. There were no differences in terms of volume of fuid administered (hypotonic group: 865 ± 853 mL; isotonic group: 778 ± 649 mL; p= 0.654) or infusion duration (hypotonic group: 24 ± 10.8 hours; isotonic group: 27.6 ± 12.8 hours; p= 0.231). A difference was found in the serum Na following the administration of maintenance fuids (hypotonic group: 137.8 ± 4.3 mmol/L; isotonic group: 140.0 ± 4.1 mmol/L, p= 0.04). None of these two maintenance fuids increased the risk of hyponatremia (Na 145 mmol/L). Conclusions. Neither hypotonic nor isotonic maintenance fluids increased the risk of developing iatrogenic hyponatremia with the 24 hour infusion.

Ensayo clínico aleatorizado sobre la administración de una solución de mantenimiento intravenosa hipotónica comparada contra una isotónica en pacientes pediátricos críticos: a randomized control trial / Hypotonic versus isotonic maintenance fuids in critically ill pediatric patients

Introducción. Las soluciones hipotónicas se han vinculado a la producción de hiponatremia iatrogénica. Objetivos. Evaluar las variaciones en el sodio sérico (NaS) tras la administración de una solución de mantenimiento intravenosa isotónica (NaCl al 0,9% en dextrosa al 5%) en comparación con una solución de mantenimiento hipotónica (NaCl al 0,45% en dextrosa al 5%). Material y métodos. Ensayo clínico aleatorizado, doble ciego y controlado. Se enrolaron pacientes pediátricos con una estadía esperada en la unidad de cuidados intensivos mayor de 24 horas, NaS normal y líquidos intravenosos > 80% de los líquidos totales de mantenimiento. La concentración sérica de Na se midió antes de colocar la solución de mantenimiento y al reducir la administración de ésta a < 80% del total del aporte. Resultados. Se incorporaron 63 pacientes, que fueron asignados en forma aleatoria a recibir una solución de mantenimiento hipotónica (n= 32) o isotónica (n= 31). Las características basales fueron similares en ambos grupos. No hubo diferencias con respecto a la cantidad de solución administrada (grupo hipotónico 865 ± 853 ml; grupo isotónico 778 ± 649 ml, p= 0,654) o el tiempo de infusión (grupo hipotónico: 24 ± 10,8 horas; grupo isotónico: 27,6 ± 12,8 horas, p= 0,231). Se encontró una diferencia en el NaS luego de la administración de las soluciones de mantenimiento (grupo hipotónico: 137,8 ± 4,3 mmol/L; grupo isotónico: 140,0 ± 4,1 mmol/L, p= 0,04). Ninguna de las dos soluciones de mantenimiento aumentó el riesgo de hiponatremia (Na 145 mmol/L). Conclusiones. Ambas soluciones de mantenimiento, en 24 horas de infusión, no aumentaron el riesgo de producir hiponatremia iatrogénica.(AU)

Introduction. Hypotonic fluids have been associated with the development of iatrogenic hyponatremia. Objectives. To assess variations in serum sodium (sNa) following the intravenous administration of isotonic maintenance fuids (0.9% NaCl/5% dextrose) compared to hypotonic maintenance fuids (0.45% NaCl/5% dextrose). Material and Methods. Randomized, controlled, double-blind clinical trial. Pediatric patients with an expected length of stay in the intensive care unit of more than 24 hours were enrolled, with normal serum Na, and IV fuids >80% of total maintenance fuids. Serum Na level was measured before administering maintenance fuids and when reducing the administration to <80% of total fuids. Results. The study included 63 patients who were randomly assigned to receive hypotonic (n= 32) or isotonic (n= 31) maintenance fuids. Baseline characteristics were similar in both groups. There were no differences in terms of volume of fuid administered (hypotonic group: 865 ± 853 mL; isotonic group: 778 ± 649 mL; p= 0.654) or infusion duration (hypotonic group: 24 ± 10.8 hours; isotonic group: 27.6 ± 12.8 hours; p= 0.231). A difference was found in the serum Na following the administration of maintenance fuids (hypotonic group: 137.8 ± 4.3 mmol/L; isotonic group: 140.0 ± 4.1 mmol/L, p= 0.04). None of these two maintenance fuids increased the risk of hyponatremia (Na 145 mmol/L). Conclusions. Neither hypotonic nor isotonic maintenance fluids increased the risk of developing iatrogenic hyponatremia with the 24 hour infusion.(AU)

Efeitos de contraceptivo hormonal oral sobre o grau de força e composição corporal de jogadoras de vôlei: um estudo piloto / Effects of oral hormonal contraceptive on the strength level and body composition of volleyball female players: a pilot study

Verificar os efeitos dos contraceptivos hormonais orais (CO) sobre o grau de força muscular e na composição corporal de mulheres jovens atletas. Participaram desse estudo 12 mulheres jovens adultas com idade superior a 18 anos, atletas amadoras de voleibol, que participavam ativamente de treinos e competições. A amostra foi divida em Grupo Contraceptivo (GCO, n=7) e Grupo Não Contraceptivo (GNCO, n=5). Foi aplicado um questionário sobre características sociodemográficas, comportamentais, de saúde e relacionadas ao treinamento. Realizaram-se medidas antropométricas, testes de força por dinamometria e de carga de uma repetição máxima. A análise dos dados foi realizada através da análise descritiva (média ± desvio padrão) e inferencial (teste t de Student não pareado ou teste de Wilcoxon não pareado) e o nível de significância aceito foi de p<0,05. Na escolha do CO como método contraceptivo, a maioria das atletas do grupo que GCO fazem uso de contraceptivos orais de terceira geração, fazem uso dos mesmo há pelo menos 5 anos e motivaram-se a usar o medicamento por sua eficiência e eficácia no controle de natalidade. As atletas do grupo GNCO utilizavam a camisinha como método contraceptivo. Em relação a composição corporal, as atletas do grupo GCO apresentaram medidas de dobras cutâneas, circunferência corporal, percentual de gordura e peso mais elevados do que as atletas do grupo GNCO, porém em nenhum dos grupos foi observado um percentual de gordura equivalente ou superior a 25%, valor considerado como na média para mulheres com idade entre 25 e 35 anos. Nenhuma das variáveis analisadas apresentou associação estatisticamente significativa com a ingestão de CO e alterações de força e performance atlética; apenas no valor da circunferência da coxa medial encontrou-se significativa limítrofe (p=0,05). No presente estudo, os COs não exerceram efeitos significantes sobre a força muscular e composição corporal de jovens atletas amadoras de voleibol.

The study aimed to evaluate potential effects of hormonal contraceptives (OC) on muscle strength and body composition in young female amateur volleyball players. Twelve women (18 or older) participated in the study, all of them were volleyball players, who were training and competing. The sample was divided into Contraceptive Group (OCG, n = 7) and Non Contraceptive Group (NOCG, n = 5). We administered a questionnaire on socio-demographic, behavioral, health-related information and training aspects. Anthropometric measurements, grip strength and maximum repetition tests were taken. Data analysis was performed with descriptive analysis (means ± standard deviations) and inferential statistics (Student's unpaired t test or Wilcoxon unpaired test) and the level of significance was set to 0.05. Among OC users, most athletes use third-generation oral contraceptives, for at least 5 years and were motivated to use the drug for their efficiency and effectiveness as a birth control method. The athletes from NOCG group used condoms as a contraceptive method. Regarding body composition, athletes from OCG group presented higher skinfolds, body circumference, body fat percentage and weight compared to athletes from NOCG group, but in none of the groups body fat was equal to or exceeded 25%, which is considered a value in average for women between the ages of 25 and 35. None of the analyzed variables showed any statistically significant association with oral contraceptives; only thigh’s circumference presented borderline significance (p=0.05). In this study, hormonal contraceptives did not exert significant effects on muscle strength and body composition of young amateur volleyball players.

Influência da distância intereletrodos e da cadência de movimento no domínio da frequência do sinal de EMG de superfície / Influence of the inter-electrodes distance and cadence of movement in the surface EMG signal frequency domain

A eletromiografia de superfície (sEMG), apesar de amplamente utilizada em investigações biomecânicas, ainda apresenta inúmeros questionamentos sobre a influência das distâncias intereletrodos (DIE) na morfologia do sinal, principalmente em contrações isotônicas. Logo, muitos dos trabalhos desenvolvidos ainda se limitam ao âmbito do laboratório de pesquisa, onde é possível estabelecer maior controle nos protocolos de registro e análise, o que não é comumente observado na prática clínico-desportiva. Dessa forma, o objetivo do estudo foi examinar os efeitos de dois protocolos de colocação de eletrodos e a realização de contrações isotônicas no domínio da frequência do sinal de sEMG. Quinze sujeitos do sexo masculino (idade: 22,8 ± 3,5 anos), todos destros, realizaram contrações dinâmicas do bíceps braquial direito com carga estimada em 20 por cento da contração voluntária máxima em três diferentes cadências (30, 45, 60bpm). Os sinais de sEMG foram registrados por meio de dois canais, cujas DIEs foram de 4,2 e 13cm, respectivamente. A avaliação dos sinais de sEMG foi baseada na frequência mediana do espectro de potencial do sinal, calculado via transformada rápida de Fourier. A DIE e a cadência foram definidas como fatores (ANOVA two-way; α = 0,05). Não foram observadas diferenças estatísticas e qualquer interação entre ambos os fatores nas três cadências (P > 0,05). Sugere-se que, independentemente da distância utilizada entre os eletrodos, uma investigação no domínio da frequência do sinal de sEMG em tarefas dinâmicas seja evitada, mesmo a partir de DIEs reduzidas, como é sugerido pela literatura, dado que variações no torque e no comprimento muscular podem corromper o sinal e, portanto, sua interpretação.

Surface electromyography (SEMG), despite being widely used in biomechanical investigations, still presents massive questioning about the influence of the distance of the inter-electrodes (DIE) in the signal morphology, especially in isotonic contractions. Thus, much of the research developed is still limited to the laboratory, where it is possible to establish better control over the recording and analysis protocols, which is not commonly observed in the clinical-sportive practice. Therefore, the aim of this study was to examine the effects of two electrodes placement protocols and the performance of isotonic contractions in the SEMG sign frequency domain. Fifteen right-handed male subjects (aged 22.8 ± 3.5 years) performed dynamic contractions of the right brachial biceps with load estimated in 20 percent of the maximum voluntary contraction in three different cadences (30, 45 and 60 bpm). The SEMG signals were registered by two channels with DIEs of 4.2 and 13 cm, respectively. The SEMG signals assessment was based on the median frequency of the potential spectrum of the signal, calculated via fast Fourier transform. DIE and cadence were defined as factors (two-way ANOVA; α = 0.05). No statistical differences or any interaction between both factors were observed in the three cadences (P> 0.05). Regardless of the distance used between electrodes, an investigation in the SEMG signal frequency domain in dynamic tasks should be avoided, even from reduced DIEs, as suggested in the literature, since variations in the torque and muscular length may disrupt the signal and hence its interpretation.

Verificação do limiar anaeróbico e a influência de bebida isotônica sobre a glicemia de atletas da equipe de futsal do município de Toledo - Pr / Anaerobic threshold assessment and the influence of isotonic drink on the glicemia of athletes from the Toledo futsal team

O presente estudo teve por objetivo verificar o limiar anaeróbico e os efeitos da ingestão de bebida isotônica durante o exercício progressivo dos atletas da equipe futsal masculino de Toledo ? PR. A amostra foi constituída por onze (11) atletas com idades entre 17 e 32 anos. Os voluntários foram escolhidos ao acaso, de acordo com a sua disponibilidade. Os mesmos não foram submetidos a nenhum tipo de treinamento antecedente aos testes. As variáveis antropométricas foram avaliadas segundo a equação de Durmin e Womersley (1974) e determinada utilizando a fórmula de Siri (1961). Para verificar o limiar anaeróbico, utilizou-se um protocolo de esforço progressivo com medidas da glicemia, uma vez que a literatura não aponta diferença significativa entre este e o protocolo do lactato sanguíneo (Simões et al., 1999). Os testes foram realizados em uma esteira mecânica da marca Moviment, com velocidades crescentes a partir de 5 Km/h até 14 Km/h, sem inclinação da rampa. A freqüência cardíaca foi mensurada com o auxílio de um frequencímetro da marca comercial Polar. A análise dos resultados obtidos demonstrou que o limiar anaeróbico médio dos atletas da equipe de futsal com ingestão de água foi numa carga de trabalho de 11 Km/h, correspondendo a uma freqüência cardíaca média de 114,7 bpm. Com relação à ingestão de bebida isotônica, a mesma manteve a glicemia elevada durante o teste, demonstrando que os carboidratos contidos na bebida estão fornecendo glicose o que, por sua vez, levaria a um protelamento da fadiga.

This study assesses the anaerobic threshold and the effects of the ingestion of isotonic drink during progressive exercise of the athletes from the Toledo male Futsal team. The sample consisted of eleven (11) athletes aged 17-32 yrs. The volunteers were chosen randomly according to their availability. They were not subjected to any kind of training prior to the tests. The anthropometric variables were assessed according to the Durmin and Womersleyïs equation (1974) and determined by using Siri?s formula (1961). A progressive effort protocol with glycemia measurements was used to outline the anaerobic threshold, as the literature does not point out any significant differences between that and the blood lactate protocol (Simões et al.,1999).The tests were carried out in a Moviment treadmill, with speeds rising from 5 - 14 km / h, without ramp tilting. The heart frequency was measured with the aid of a Polar frequencymeter. The analysis of the obtained results demonstrated the Futsal athletes? average anaerobic threshold, with ingestion of water, 11 Km/h-workload, corresponding to an average heart frequency of 114.7 bpm. With respect to the isotonic drink intake, it maintained high glycemia levels during the test demonstrating that the carbohydrates in the drink provide glucose which, in turns, would lead to the retardation of fatigue.