Contaminación atmosférica y asma en niños / Outdoor air pollution and asthma in children

El asma en niños es una condición prevalente y con un significativo impacto en la calidad de vida del niño y su cuidador. Un alto porcentaje de los niños están expuestos a la contaminación atmosférica, lo que se traduce en un significativo impacto en su salud respiratoria. Los niños son un grupo especialmente vulnerable por razones fisiológicas, medioambientales y de comportamientos propios de la edad. Existe suficiente evidencia que algunos contaminantes atmosféricos son capaces de aumentar los síntomas de asma y desencadenar exacerbaciones en niños asmáticos. También existe evidencia creciente que la exposición prolongada y precoz a contaminantes atmosféricos pueden aumentar el riesgo de desarrollar asma, especialmente los contaminantes relacionados con el tráfico vehicular. Estos efectos adversos disminuyen cuando disminuye la contaminación atmosférica producto de las regulaciones ambientales. Estudios sobre la carga atribuible estiman que un 13% de los nuevos niños asmáticos pueden deberse a la contaminación atmosférica. El sistema respiratorio y el sistema inmunológico del niño están en desarrollo, por lo que exposiciones a contaminantes atmosféricos pueden tener consecuencias de largo plazo. Existen varios mecanismos identificados que apoyan los resultados de los estudios epidemiológicos destacando el daño por estrés oxidativo. Los médicos que atienden niños tienen que tomar en cuenta este conocimiento e incorporarlo a su práctica clínica.

Asthma in children is a prevalent condition with a significant impact on the quality of life of the child and their caregiver. A high percentage of children are exposed to air pollution, which has a significant impact on their respiratory health. Children are a particularly vulnerable group for age-specific physiological, environmental and behavioral reasons. There is sufficient evidence that some air pollutants are capable of increasing asthma symptoms and triggering exacerbations in asthmatic children. There is also growing evidence that early and prolonged exposure to air pollutants can increase the risk of developing asthma, especially traffic-related air pollution. These adverse effects decrease when atmospheric pollution decreases as a result of environmental regulations. Studies on attributable burden estimate that 13% of new asthmatics in children may occur due to air pollution. The respiratory system and the immune system of the child are developing, so exposure to air pollutants can have long-term consequences. There are several identified mechanisms that support the results of epidemiological studies highlighting damage from oxidative stress. Physicians caring for children need to take this knowledge into account and incorporate it into their clinical practice.

Actualización de la prueba de provocación bronquial con ejercicio (PPBE) / Update of the bronchial provocation test with exercise

The bronchial challenge test with exercise aims to demonstrate the presence of exercise-induced bronchial hyperreactivity, characteristic of bronchial asthma. Its realization is well standardized, requiring special environmental conditions, preparation and submaximum effort of the patient. The response is measured by spirometry, and it is considered a positive exercise test a drop in the expired volume at the first second (FEV1) of 10%. This article describes the elements necessary to facilitate this exam, according to national and international standards and guidelines.

La prueba de provocación bronquial con ejercicio tiene como objetivo demostrar la presencia de hiperreactividad bronquial inducida por ejercicio, característica del asma bronquial. Su realización está bien estandarizada, requiriendo de condiciones ambientales especiales, preparación y esfuerzo submáximo del paciente. La respuesta se mide mediante espirometría, y se considera una prueba de provocación con ejercicio positivo, a una caída del volumen espirado al primer segundo (VEF1) del 10%. En este artículo se describen los elementos necesarios para facilitar la realización de este examen, acorde a normas y guías nacionales e internacionales.

Actualización en la prueba de provocación bronquial con metacolina en el niño / Update in the bronchial challenge test with methacholine in children

This document updates the recommendations of the bronchial challenge test with methacholine in children. It is based primarily on the recommendations contained in the guide on the technical standard of the bronchial challenge test for methacholine from the European Society of Respiratory Diseases. The main change is the recommendation to use PD20 (methacholine dose that causes a 20% drop in FEV1) instead of PC20 (methacholine concentration that causes a 20% drop in FEV1), which allows for comparable results when different devices and different protocols are used.

Este documento actualiza las recomendaciones de la prueba de provocación bronquial con metacolina en niños. Se basa fundamentalmente en las recomendaciones contenidas en la guía sobre el estándar técnico de la prueba de provocación bronquial de metacolina de la Sociedad Europea de Enfermedades Respiratorias. El principal cambio es la recomendación de utilizar la PD20 (dosis de metacolina que provoca una caída de 20% del VEF1) en vez de PC20 (concentración de metacolina que provoca una caída del 20% en el VEF1), lo cual permite tener resultados comparables cuando se usan diferentes dispositivos y diferentes protocolos.

Actualización en espirometría en el preescolar / Preeschools spirometry update

Spirometry is better pulmonary function test for evaluating preschoolers with chronic lung disease and recurrent wheeze. It is useful, accessible and very good performance. For a correct interpretation it must be under the conditions specially controlled for this age group. In this review, product of the work done during the year 2018, by the Committee on pulmonary function in pediatric pulmonology Chilean society, will be showcased aspects for the realization and interpretation of spirometry in preschool children, with emphasis on the differences in the criteria typically described for older children and adults.

La espirometría es la prueba de función pulmonar más adecuada para evaluar a preescolares con enfermedades pulmonares crónicas y sibilancias recurrentes. Es útil, accesible y de buen rendimiento. Para una correcta interpretación debe realizarse bajo las condiciones especialmente normadas para este grupo etario. En esta revisión, producto del trabajo realizado durante el año 2018, por la comisión de función pulmonar de la sociedad Chilena de Neumología Pediátrica, se expondrán los aspectos actualizados para la realización e interpretación de la espirometría en preescolares, con énfasis en las diferencias de los criterios clásicamente descritos para niños mayores y adultos.

Actualización en espirometría y curva flujo / volumen en escolares y adolescentes / School and adolescent spirometry and flow / volume curve update

Spirometry is the most commonly used test to evaluate lung function in children and adults. To obtain good quality results, several requirements must be fulfilled: professional capacity of the technician, the quality of the equipment, the patient's collaboration, the use of appropriate reference standards. The purpose of spirometry is to define types of ventilatory alterations of the central and peripheral airways, to evaluate the response to bronchodilators and to guide the presence of restrictive diseases. The new consensus of national and international experts are described, which have been perfecting several aspects of this test.

La espirometría es el examen más comúnmente utilizado para evaluar la función pulmonar en niños y adultos. Para obtener resultados de buena calidad deben cumplirse varios requisitos, desde la capacidad profesional del técnico, calidad de los equipos, colaboración del paciente y utilización de patrones de referencia adecuados. La espirometría tiene como utilidad definir alteraciones ventilatorias obstructivas de vía aérea central y periférica, evaluar respuesta a broncodilatador y orientar al diagnóstico de enfermedades restrictivas. Se describen los nuevos consensos de expertos nacionales e internacionales, los cuales han ido perfeccionando varios aspectos de este examen.

[Quality scale for preschool spirometry interpretation]. / Elaboración de una escala de calidad para la interpretación de espirometrías en preescolares.

Since 2007, there are international guidelines for implementation and interpretation of spirometry in preschool children. A percentage of these patients cannot obtain maneuvers that meet all eligibility criteria. The objective of this study was to develop a quality scale for interpreting these partially acceptable spirometry. MATERIAL AND METHOD: Delphi methodology was used, which allows to reach consensus among experts analyzing a defined problem. We invited to participate pediatric pneumologists dedicated to lung function and who participated actively in scientific specialty societies in Chile. Successive rounds were conducted with questionnaires about criteria used to assess spirometry in preschool children. These criteria define the acceptability of spirometric maneuvers according to international guidelines. Proposed quality grades were “very good”, “good”, “fair” and “bad”. RESULTS: Thirteen of the 15 invited experts accepted our invitation. In the first round 9 disagreed with the degree of “regular” quality. In the second round this was removed and 11 experts answered, 9 of them agreed with the use of this new version. The most contentious criterion was the end of expiration. CONCLUSION: Most experts agreed with the final scale, using “very good”, “good” and “bad” judgments. This would help to improve the performance of spirometry in children between 2 and 5 years.

Air pollution, PM2.5 composition, source factors, and respiratory symptoms in asthmatic and nonasthmatic children in Santiago, Chile.

The objective of this study was to determine the association of respiratory symptoms and medication use and exposure to various air pollutants, PM2.5 components, and source factors in a panel of asthmatic and nonasthmatic children in Santiago, Chile. To this end, 174 children (90 asthmatics and 84 nonasthmatics) were followed throughout the winter months of 2010 and 2011. During the study period, children filled out daily diaries to record respiratory symptoms and medication use. Air pollution data were obtained from government central site measurements and a PM2.5 characterization campaign. PM2.5 source factors were obtained using positive matrix factorization (PMF). Associations of symptoms and exposure to pollutants and source-factor daily scores were modeled separately for asthmatic and nonasthmatic children using mixed logistic regression models with random intercepts, controlling for weather, day of the week, year, and viral outbreaks. Overall, high concentrations of air pollutants and PM2.5 components were observed. Six source factors were identified by PMF (motor vehicles, marine aerosol, copper smelter, secondary sulfates, wood burning, and soil dust). Overall, single pollutant models showed significant and strong associations between 7-day exposures for several criteria pollutants (PM2.5, NO2, O3), PM2.5 components (OC, K, S, Se, V), and source factors (secondary sulfate) and coughing, wheezing and three other respiratory symptoms in both in asthmatic and nonasthmatic children. No associations were found for use of rescue inhalers in asthmatics. Two-pollutant models showed that several associations remained significant after including PM2.5, and other criteria pollutants, in the models, particularly components and source factors associated with industrial sources. In conclusion, exposure to air pollutants, especially PM2.5, NO2, and O3, were found to exacerbate respiratory symptoms in both asthmatic and nonasthmatic children. Some of the results suggest that PM2.5 components associated with a secondary sulfate source may have a greater impact on some symptoms than PM2.5. In general, the results of this study show important associations at concentrations close or below current air quality standards.

Elaboración de una escala de calidad para la interpretación de espirometrías en preescolares / Quality scale for preschool spirometry interpretation

Desde el año 2007 existen guías internacionales para la realización e interpretación de espirometrías en preescolares. Un porcentaje de estos pacientes no logra obtener maniobras que cumplan con todos los criterios de aceptabilidad. El objetivo de este estudio fue desarrollar una escala de calidad mediante el juicio de expertos para interpretar estas espirometrías parcialmente aceptables. Material y Método: Se utilizó metodología Delphi, la cual permite llegar a un consenso entre expertos analizando un problema definido. Para esto se invitó a participar a pediatras especialistas en enfermedades respiratorias con dedicación en función pulmonar y que participan activamente en las sociedades científicas de la especialidad en Chile. Se realizaron rondas sucesivas solicitándoles su opinión por escrito acerca de los criterios utilizados para valorar espirometrías realizadas en preescolares. Estos criterios son los que definen la aceptabilidad de las maniobras espirométricas según las guías internacionales. Los grados de calidad propuestos fueron: “muy bueno”, “bueno”, “regular” y “malo”. Resultados: Participaron 13 de los 15 expertos invitados. En la primera ronda 9 de ellos estuvieron en desacuerdo con el grado de calidad “regular”. En la segunda ronda esta se eliminó y respondieron 11 expertos; 9 de ellos estuvieron de acuerdo con la utilización de esta nueva versión. El criterio más discutido fue el final de la espiración. Conclusión: La mayoría de los expertos estuvieron de acuerdo con la escala final, usando las apreciaciones “muy bueno”, “bueno” y “malo”. Esta contribuiría a mejorar el rendimiento de las espirometrías realizadas en niños entre 2 y 5 años.

Since 2007, there are international guidelines for implementation and interpretation of spirometry in preschool children. A percentage of these patients cannot obtain maneuvers that meet all eligibility criteria. The objective of this study was to develop a quality scale for interpreting these partially acceptable spirometry. Material and Method: Delphi methodology was used, which allows to reach consensus among experts analyzing a defined problem. We invited to participate pediatric pneumologists dedicated to lung function and who participated actively in scientific specialty societies in Chile. Successive rounds were conducted with questionnaires about criteria used to assess spirometry in preschool children. These criteria define the acceptability of spirometric maneuvers according to international guidelines. Proposed quality grades were “very good”, “good”, “fair” and “bad”. Results: Thirteen of the 15 invited experts accepted our invitation. In the first round 9 disagreed with the degree of “regular” quality. In the second round this was removed and 11 experts answered, 9 of them agreed with the use of this new version. The most contentious criterion was the end of expiration. Conclusion: Most experts agreed with the final scale, using “very good”, “good” and “bad” judgments. This would help to improve the performance of spirometry in children between 2 and 5 years.

[Association of exhaled nitric oxide with asthma and atopy among children living in Santiago, Chile]. / Óxido nítrico exhalado, asma y atopia: análisis en un panel de niños en Santiago, Chile.

BACKGROUND: Chronic airway inflammation is a central process in asthma. Measurement of exhaled nitric oxide (eNO) is a non-invasive biomarker of eosinophilic airway inflammation. AIM: To measure eNO levels in a population of asthmatic and non-asthmatic children and to evaluate their relationship with asthma and atopy. MATERIAL AND METHODS: We studied 143 asthmatic and non-asthmatic children aged 6 to 14 years attended a hospital and primary health service. Participants were tested for allergies and followed during the winter months of 2010 and 2011. They were visited regularly at their homes and eNO levels were measured on each visit using a handheld equipment. Mean eNO distribution were compared by the presence of asthma or atopy using t-test and regression models. RESULTS: No significant differences for mean eNO levels were detected, according to presence of asthma or atopy, by any of the statistical methods used. Regression models showed significant effects for age but not for sex. CONCLUSIONS: There were no differences in eNO levels in the studied children by the presence of asthma or atopy.

Óxido nítrico exhalado, asma y atopia: análisis en un panel de niños en Santiago, Chile / Association of exhaled nitric oxide with asthma and atopy among children living in Santiago, Chile

Background: Chronic airway inflammation is a central process in asthma. Measurement of exhaled nitric oxide (eNO) is a non-invasive biomarker of eosinophilic airway inflammation. Aim: To measure eNO levels in a population of asthmatic and non-asthmatic children and to evaluate their relationship with asthma and atopy. Material and Methods: We studied 143 asthmatic and non-asthmatic children aged 6 to 14 years attended a hospital and primary health service. Participants were tested for allergies and followed during the winter months of 2010 and 2011. They were visited regularly at their homes and eNO levels were measured on each visit using a handheld equipment. Mean eNO distribution were compared by the presence of asthma or atopy using t-test and regression models. Results: No significant differences for mean eNO levels were detected, according to presence of asthma or atopy, by any ofthe statistical methods used. Regression models showed significant effects for age but not for sex. Conclusions: There were no differences in eNO levels in the studied children by the presence of asthma or atopy.

[Assessment of disease control among asthmatic adolescents]. / Control de asma en adolescentes.

BACKGROUND: The clinical assessment of asthma control is fundamental to evaluate the results of treatment. The Asthma Control Test (ACT) is a questionnaire with five scored items, that differentiates between a well controlled or uncontrolled asthma. It has a Spanish version and has been applied in different countries. AIM: To assess asthma control using the ACT and compare it with the clinical assessment of specialists in a group of pediatric patients. MATERIAL AND METHODS: The ACT was applied to 220 adolescents aged 12 to 17 years, 54% males, with persistent asthma, attended at a respiratory disease unit of a pediatric hospital. The concordance between ACT results and the assessment of specialists was also evaluated. RESULTS: According to ACT and specialists, asthma was controlled in 54% and 63% of patients, respectively. There was a weak concordance between ACT and specialists assessment (Kappa index: 0.27; 95% confidence intervals: 0.14-0.4). The degree of asthma control decreased along with increasing severity of the disease (chi2 = 10.128, p =0.001). CONCLUSIONS: Half of the evaluated asthmatic adolescents do not have an adequate control of their disease. Severity of the disease is inversely related to the degree of control.

Control de asma en adolescentes / Assessment of disease control among asthmatic adolescents

Background: The clinical assessment of asthma control is fundamental to evaluate the results of treatment. The Asthma Control Test (ACT) is a questionnaire with five scored items, that differentiates between a well controlled or uncontrolled asthma. It has a Spanish version and has been applied in different countries. Aim: To assess asthma control using the ACT and compare it with the clinical assessment of specialists in a group of pediatric patients. Material and methods: The ACT was applied to 220 adolescents aged 12 to 17 years, 54 percent males, with persistent asthma, attended at a respiratory disease unit of a pediatric hospital. The concordance between ACT results and the assessment of specialists was also evaluated. Results: According to ACT and specialists, asthma was controlled in 54 percent and 63 percent of patients, respectively. There was a weak concordance between ACT and specialists assessment (Kappa index: 0.27; 95 percent confidence intervals: 0.14-0.4). The degree of asthma control decreased along with increasing severity of the disease ( percentz = 10.128, p =0.001). Conclusions: Half of the evaluated asthmatic adolescents do not have an adequate control of their disease. Severity of the disease is inversely related to the degree of control