RESUMEN
Introduction: The use of peripheral blood progenitor cells (PBPCs) as a source for hematopoietic stem cell transplantation (HSCT) in pediatric healthy donors is still under debate. The risk of a central venous catheter (CVC) placement and catheter-related complications continue to be the main arguments to discourage its use. Methods: we present a retrospective analysis of 140 PBPC collections in pediatric patients and donors, describing adverse events (AE) related to CVCs as well as the influence of catheterrelated variables on the efficiency of the leukapheresis. Results: 14 CVC-related AEs were recorded (10%). The most common was fever in 5 patients, 4 of which had a catheter-related bacteriemia. Thrombotic events were only observed in 3 patients with active malignancy. A healthy donor presented a moderate bleeding after catheter withdrawal that resolved with local measures, and none of the rest presented any AE. Regarding variables related to the development of AEs, the subject group (patient or donor) was the only one significantly associated (p < 0.0001). Of interest, efficiency was also related to catheter location, being worse in those located in the femoral vein than in into the jugular or the subclavian veins (p < 0.05). In a multivariate analysis, the only variable significantly associated was catheter size (beta 0.238, p < 0.01). Discussion: Placing a CVC for PBPC collection in pediatric subjects is overall safe; CVC-related complications in pediatric healthy donors are very rare. Furthermore, we should try to place catheters of the largest caliber possible, since the efficiency of the collection is related to this variable.
RESUMEN
El efecto de la edad relativa se refiere a las diferencias cronológicas de sujetos pertenecientes a un mismo grupo de edad, que puede provocar que los nacidos en los primeros meses del año parezcan más talentosos. El objetivo de este estudio fue analizar la posible existencia del efecto de la edad relativa en la natación española. Para llevarlo a cabo se consideraron los 100 mejores resultados en piscina de 50 metros de las últimas seis temporadas (2015-2021), para todas las edades de las categorías con campeonatos nacionales, en ambos sexos y en los cuatro estilos. El análisis se realizó sobre 28.373 resultados obtenidos de la base de datos de la Real Federación Española de Natación, tomando como referencia las fechas de nacimiento de los nadadores. Para identificar si existe el efecto de la edad relativa en la natación en España se aplicó el odds ratio y la prueba estadística chi cuadrado. Así, para calcular las posibles diferencias entre los rendimientos medios entre los trimestres de nacimiento de los nadadores, se realizó́ un análisis de varianza. Los resultados mostraron una distribución desigual de las fechas de nacimiento por trimestres y unos rendimientos medios diferentes para casi todos los grupos de edad, en ambos géneros. En conclusión, se puede decir que la sobrerrepresentación de deportistas en los primeros trimestres del año, y la diferencia en cuanto al éxito deportivo alcanzado, son dos efectos de la edad relativa a considerar. (AU)
The relative age effect refers to chronological differences in subjects belonging to the same age group, which may cause those born in the first months of the year to appear more talented. The aim of this research is to analyse the effect of relative age in Spanish swimming. The 100 best results in pool of 50 meters of the last six seasons (2015-2021) were analysed for all ages of the categories with national championships, in both genders and in the four styles. The sample included 28.373 results obtained from the database of the Royal Spanish Swimming Federation, taking as reference the dates of birth of the swimmers. To analyse the effect of relative age in Spanish swimming, the Chi-squared statistical est was used. The possible differences between the average yields between the birth quarters of the swimmers was calculated by an analysis of variance. The results showed an unequal distribution of birth dates by trimesters and different average yields for almost all age groups, in both genders. In conclusion, it can be said that the over-representation of athletes in the first quarters of the year, and the difference in terms of sports success achieved, are two effects of the relative age to consider. (AU)