Disfunción de la pequeña vía aérea en niños con asma controlada / Small Airway Dysfunction in Children With Controlled Asthma

Introducción: El asma se caracteriza por una inflamación crónica de las vías respiratorias centrales y distales. El objetivo de este estudio ha sido evaluar la vía aérea pequeña (VAP) en niños con asma moderada y/o grave con FEV1 normal. Métodos: Estudio abierto, prospectivo, observacional y transversal con inclusión consecutiva de casos con asma moderada o grave, bajo tratamiento clínico habitual con FEV1 basal normal. Se ha determinado la FEno a flujos múltiples (CAno), resistencias y reactancia oscilatorias (R5-R20, X5), espirometría forzada (FEV1, FEF25-75), pletismografía corporal total (RV/TLC) y prueba de broncodilatación. La afectación de la VAP se definió por: Cano > 4,5 ppb, R5-R20 > 0,147kPa/L/s, X5 <-0,18kPa/L, FEF25-75 < -1,65 z-score, RV/TL > 33%. El mal control de asma se definió por ≤ 19 puntos en el cuestionario ACT o ≤ 20 en c-ACT. Resultados: Cohorte de 100 casos, 76 con asma moderada y 24 con asma grave, 71 niños clasificados como mal controlados y 29 bien controlados. El 77,78% del grupo con todas las determinaciones correctas (n =7 2) mostró ≥ 1 parámetro alterado de VAP y el 48,61% ≥ 2 parámetros. No hubo diferencias entre los casos bien y mal controlados. Conclusiones: Los niños con asma moderada y grave, con el FEV1 preservado, muestran un fenotipo de VAP disfuncionante. En nuestra muestra, la evaluación de la VAP mediante las técnicas descritas, no aporta información sobre el control habitual de la enfermedad

Introduction: Asthma is characterized by chronic inflammation of the central and distal airways. The aim of this study was to assess the small airway (SA) of children with moderate-severe asthma with normal FEV1. Methods: This was an open-label, prospective, observational, cross-sectional study with consecutive inclusion of patients with moderate-severe asthma, receiving standard clinical treatment, with normal baseline FEV1. We determined multiflow FEno (CAno), oscillatory resistance and reactance (R5-R20, X5), forced spirometry (FEV1, FEF25-75), total body plethysmography (RV/TLC) and bronchodilation test. SA involvement was defined as: Cano > 4.5 ppb, R5-R20 > 0.147kPa/L/s, X5< -0.18kPa/L, FEF25-75 < -1.65 z-score, RV/TLC > 33%. Poor asthma control was defined as ≤ 19 points on the ACT questionnaire or ≤ 20 on the c-ACT. Results: In a cohort of 100 cases, 76 had moderate asthma and 24 had severe asthma; 71 children were classified as poorly controlled and 29 were well-controlled. In total, 77.78% of the group with all the correct determinations (n=72) showed ≥ 1 altered SA parameter and 48.61% ≥ 2 parameters. There were no differences between well-controlled or poorly controlled cases. Conclusions: Children with moderate-severe asthma, with normal FEV1, show a phenotype of dysfunctional SA. In our series, the evaluation of SA using the techniques described above did not provide information on disease control

Small Airway Dysfunction in Children With Controlled Asthma. / Disfunción de la pequeña vía aérea en niños con asma controlada.

INTRODUCTION: Asthma is characterized by chronic inflammation of the central and distal airways. The aim of this study was to assess the small airway (SA) of children with moderate-severe asthma with normal FEV1. METHODS: This was an open-label, prospective, observational, cross-sectional study with consecutive inclusion of patients with moderate-severe asthma, receiving standard clinical treatment, with normal baseline FEV1. We determined multiflow FEno (CAno), oscillatory resistance and reactance (R5-R20, X5), forced spirometry (FEV1, FEF25-75), total body plethysmography (RV/TLC) and bronchodilation test. SA involvement was defined as: CAno>4.5 ppb, R5-R20>0.147kPa/L/s, X5<-0.18kPa/L, FEF25-75<-1.65 z-score, RV/TLC>33%. Poor asthma control was defined as ≤ 19 points on the ACT questionnaire or ≤ 20 on the c-ACT. RESULTS: In a cohort of 100 cases, 76 had moderate asthma and 24 had severe asthma; 71 children were classified as poorly controlled and 29 were well-controlled. In total, 77.78% of the group with all the correct determinations (n=72) showed ≥ 1 altered SA parameter and 48.61% ≥ 2 parameters. There were no differences between well-controlled or poorly controlled cases. CONCLUSIONS: Children with moderate-severe asthma, with normal FEV1, show a phenotype of dysfunctional SA. In our series, the evaluation of SA using the techniques described above did not provide information on disease control.