[Agreement between two devices for measuring exhaled nitric oxide]. / Concordancia entre dos dispositivos de medida de óxido nítrico exhalado.

BACKGROUND: Measurement of fractional exhaled nitric oxide (FENO) is a non-invasive marker of eosinophilic airway inflammation that can be useful in asthma diagnosis and control, as well as in treatment monitoring. OBJECTIVE: We studied the correlation between two techniques for measuring FENO: the chemiluminescence-based analyzer (NIOX, Aerocrine, Sweden) and a new portable electrochemical sensor-based analyzer (NIOX-MINO, Aerocrine). MATERIAL AND METHODS: FENO was measured by the single breath on-line method. In all children, three consecutives measurements were obtained with NIOX, with a maximum of six attempts, and the arithmetic mean was calculated. Next, using NIOX-MINO, a single measurement was made successively in each of the children. The variables analyzed were sex, age, height, weight, diagnosis, treatment, NIOX-MINO value, mean of three values obtained with NIOX and the NO elimination rate (nL/min). For the statistical analysis, the Bland-Altman plot was used to compare the means and the differences between measurements of FENO from NIOX and NIOX-MINO. The agreement between the two analyzers was estimated by Cohen's Kappa statistic. RESULTS: Thirty children were included, 14 (46.67%) boys and 16 (53.33%) girls. The mean age was 11.3+/-3.09 years. All of the children successfully performed the measurements with two analyzers. The relationship between the means and the differences in the values obtained with NIOX-MINO and NIOX were statistically significant (p<0.005). In addition, Cohen's Kappa statistic (0.78) suggested a high degree of agreement between the results obtained with the two devices. CONCLUSIONS: The two analyzers, NIOX-MINO and NIOX, were not equivalent. There was good agreement between the FENO values measured with the two devices. Measurement of FENO with the portable electrochemical sensor-based analyzer (NIOX-MINO) is valid and feasible in children older than 5 years.

Concordancia entre dos dispositivos de medida de óxido nítrico exhalado / Agreement between two devices for measuring exhaled nitric oxide

Antecedentes La fracción exhalada de óxido nítrico (FENO) se comporta como un marcador no invasivo de inflamación eosinófila de la vía aérea, que resulta de utilidad en el diagnóstico de asma, en el control de la enfermedad y en la monitorización del tratamiento. Objetivo Analizar la concordancia entre dos dispositivos de medida de la FENO, un analizador de quimioluminiscencia estacionario (NIOX(R), Aerocrine, Suecia) y un analizador electroquímico portátil (NIOX-MINO(R), Aerocrine, Suecia). Material y métodos Las medidas se han realizado mediante registro on-line de respiración única (single breath on-line measurement). Se han obtenido tres medidas consecutivas con el analizador NIOX(R), máximo de seis intentos, y se ha calculado la media. Asimismo, y de forma sucesiva en cada uno de los niños, se realizó otra medición con el analizador NIOX-MINO(R). Se han analizado las variables cuantitativas edad, talla, peso, valor NIOX-MINO(R), valor medio NIOX(R) y flujo de óxido nítrico (NO) (nl/min), y las variables cualitativas sexo, diagnóstico y tratamiento. En el análisis estadístico se han estudiado la regresión de las medias de FENO (Bland-Altman) y el grado de acuerdo entre ambos dispositivos (estadístico kappa de Cohen). Resultados Se han estudiado 30 niños, edad media 11,3 ± 3,09 años, distribuidos en 14 varones (46,67 %) y 16 mujeres (53,33 %). El 100 % de los casos realizaron con éxito las mediciones con ambos dispositivos. La regresión de las medias obtenidas fue significativa, tanto en valores absolutos como relativos. Asimismo, hubo acuerdo entre los resultados con ambos dispositivos (kappa de Cohen, 0,78). Conclusiones Los dos sistemas estudiados de determinación de la FENO no son equivalentes. Existe entre ambas técnicas un acuerdo sustancial en las determinaciones obtenidas. La FENO determinada mediante técnica electroquímica con sistemas portátiles es válida en niños mayores de 5 años

Background Measurement of fractional exhaled nitric oxide (FENO) is a non-invasive marker of eosinophilic airway inflammation that can be useful in asthma diagnosis and control, as well as in treatment monitoring. Objective We studied the correlation between two techniques for measuring FENO: the chemiluminescence-based analyzer (NIOX(R), Aerocrine, Sweden) and a new portable electrochemical sensor-based analyzer (NIOX-MINO(R), Aerocrine). Material and methods FENO was measured by the single breath on-line method. In all children, three consecutives measurements were obtained with NIOX(R), with a maximum of six attempts, and the arithmetic mean was calculated. Next, using NIOX-MINO(R), a single measurement was made successively in each of the children. The variables analyzed were sex, age, height, weight, diagnosis, treatment, NIOX-MINO(R) value, mean of three values obtained with NIOX(R) and the NO elimination rate (nL/min). For the statistical analysis, the Bland-Altman plot was used to compare the means and the differences between measurements of FENO from NIOX(R) and NIOX-MINO(R). The agreement between the two analyzers was estimated by Cohen's Kappa statistic. Results Thirty children were included, 14 (46.67 %) boys and 16 (53.33 %) girls. The mean age was 11.3 ± 3.09 years. All of the children successfully performed the measurements with two analyzers. The relationship between the means and the differences in the values obtained with NIOX-MINO(R) and NIOX(R) were statistically significant (p < 0.005). In addition, Cohen's Kappa statistic (0.78) suggested a high degree of agreement between the results obtained with the two devices. Conclusions The two analyzers, NIOX-MINO(R) and NIOX(R), were not equivalent. There was good agreement between the FENO values measured with the two devices. Measurement of FENO with the portable electrochemical sensor-based analyzer (NIOX-MINO(R)) is valid and feasible in children older than 5 years

[Current prevalence of asthma in schoolchildren in San Sebastián (Spain)]. / Prevalencia actual de asma en escolares en San Sebastián.

OBJECTIVE: To determine the current prevalence of asthma in children aged 6-12 years old in San Sebastian (Guipuzcoa, Spain). PATIENTS AND METHODS: An observational, cross sectional study was performed in 6-12-year-old children in schools. The International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire was employed. Bronchial hyperresponsiveness was investigated using the free running test, with peak expiratory flow (PEF) measured with a peak flow meter as the main measurement. The ISAAC questionnaire (n = 919) was distributed to 460 boys (50.1%) and 459 girls (49.9%) with a mean age of 8 years (SD 1.87). The response rate to the questionnaire was 93 % (n = 855). Participation in the free running test was 90.8% (n = 835). A total of 89.88% of the children (n = 826) completed both tests. RESULTS: The questionnaire of symptoms and signs compatible with asthma revealed a current prevalence of asthma of 25.56% (n = 216) and a cumulative prevalence of 25.44% (n = 85). Nocturnal asthma was found in 29.37% (n = 47) and severe asthma in 9.27% (n = 14). Bronchial hyperresponsiveness was found in 23% of the participants. An epidemiological diagnosis of asthma (asthma-related symptoms plus bronchial hyperresponsiveness) was made in 6.54%. CONCLUSIONS: The current prevalence of asthma in 6-12-year-old schoolchildren in San Sebastian, determined through symptoms and signs compatible with asthma in the previous year and a positive free running test, is similar to that reported in other national studies.

Prevalencia actual de asma en escolares en San Sebastián / Current prevalence of asthma in schoolchildren in San Sebastián (Spain)

Objetivo: Determinar la prevalencia actual de asma en escolares de 6 a 12 años en San Sebastián (España). Pacientes y métodos: Estudio observacional y transversal en centros escolares en niños de 6 a 12 años, mediante cuestionario de síntomas relacionados con asma (International Study of Asthma and Allergies in Childhood, ISAAC) y estudio de la hiperreactividad bronquial (HRB) (carrera al aire libre con esfuerzo máximo), utilizando como medida principal el flujo espiratorio máximo (FEM) medido con mini-wright. Se distribuyó el cuestionario ISAAC (n = 919) a 460 niños (50,1 %) y 459 niñas (49,9 %), con una media de edad de 8 años (desviación estándar [DE]: 1,87). La tasa de respuesta al cuestionario ISAAC fue del 93 % (n = 855). La participación en el test de carrera al aire libre fue del 90,8 % (n = 835). Completaron ambas pruebas el 89,88 % (n = 826). Resultados: Cuestionario de signos y síntomas compatibles con asma: prevalencia actual del asma, 25,56 % (n = 216); prevalencia acumulada, 25,44 % (n = 85); asma nocturna, 29,37 % (n = 47), y asma grave, 9,27 % (n = 14). Se ha objetivado HRB en el 23 % de los participantes. El diagnóstico epidemiológico del asma (síntomas relacionados con asma más HRB) ha sido del 6,54 %. Conclusiones: La prevalencia actual del asma en San Sebastián en escolares de 6-12 años, determinada mediante signos y síntomas compatibles con asma durante el último año y test de carrera libre positivo, es similar a otros estudios nacionales

Objective: To determine the current prevalence of asthma in children aged 6-12 years old in San Sebastian (Guipuzcoa, Spain). Patients and methods: An observational, cross sectional study was performed in 6-12-year-old children in schools. The International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire was employed. Bronchial hyperresponsiveness was investigated using the free running test, with peak expiratory flow (PEF) measured with a peak flow meter as the main measurement. The ISAAC questionnaire (n = 919) was distributed to 460 boys (50.1 %) and 459 girls (49.9 %) with a mean age of 8 years (SD 1.87). The response rate to the questionnaire was 93 % (n = 855). Participation in the free running test was 90.8 % (n = 835). A total of 89.88 % of the children (n = 826) completed both tests. Results: The questionnaire of symptoms and signs compatible with asthma revealed a current prevalence of asthma of 25.56 % (n = 216) and a cumulative prevalence of 25.44 % (n = 85). Nocturnal asthma was found in 29.37 % (n = 47) and severe asthma in 9.27 % (n = 14). Bronchial hyperresponsiveness was found in 23 % of the participants. An epidemiological diagnosis of asthma (asthma-related symptoms plus bronchial hyperresponsiveness) was made in 6.54 %. Conclusions: The current prevalence of asthma in 6-12-year-old schoolchildren in San Sebastian, determined through symptoms and signs compatible with asthma in the previous year and a positive free running test, is similar to that reported in other national studies

[Agreement between tracheal auscultation and pulmonary function in methacholine bronchial inhalation challenge in asthmatic children]. / Medida de la respuesta bronquial a la metacolina en niños asmáticos mediante la auscultación traqueal.

BACKGROUND: PC wheezing (PCw) is defined as the concentration of methacholine at which wheeze is detected on auscultation of the trachea. PCw has been suggested as a measure of bronchial hyperresponsiveness in methacholine challenge testing (MCT). OBJECTIVE: The aim of this study was to determine the agreement between the concentration of methacholine that produces a 20 % decrease in forced expiratory volume in 1 second (FEV1) (PC20) and PCw in MCT in asthmatic children. PATIENTS AND METHODS: Eighteen asthmatic children with a mean age of 11.5 years (range: 6-16 years) were studied. Fifteen of the children were under treatment with inhaled glucocorticoids. MCT was performed according to the guidelines of the American Thoracic Society (1999) using a Hudson nebulizer calibrated to obtain a mean output of 0.14 ml/min. After each nebulization, two independent observers registered FEV1 and tracheal auscultation. FEV1 was determined by forced spirometry 30 and 90 seconds after the end of nebulization and PC20 was registered (exponential model). Respiratory rate and transcutaneous oxygen saturation were continuously monitored. Tracheal auscultation was performed at 0, 60 and 120 seconds after the end of nebulization. The end point was defined as the appearance of wheezing over the trachea. The values of PC20 and PCw, as well as the concentration of methacholine corresponding to a decrease in FEV1 equal to or higher than 20 %, were compared using Student's matched pairs-test and Wilcoxon's test. The degree of agreement between variables was compared by using Bland-Altman's test. RESULTS: MCT was positive in 17 of 18 patients. No differences were found between PC20 and PCw (p 0.15). Both variables showed agreement in 12 of 17. A clear association was found between both measures (log PCw, log PC20): R: 0.92; p < 0.001. The mean decrease in FEV1 on reaching PCw was 24.8 % (range: 10-41). No adverse effects were observed. CONCLUSION: The agreement between PC20 and PCw in MCT in asthmatic children is excellent. PCw could be helpful in determining bronchial hyperresponsiveness in young asthmatic children in whom spirometry is not feasible.

Medida de la respuesta bronquial a la metacolina en niños asmáticos mediante la auscultación traqueal / Agreement between tracheal auscultation and pulmonary function in methacholine bronchial inhalation challenge in asthmatic children

Antecedentes: La PC wheezing (PCw) o concentración de metacolina que provoca sibilancias auscultables en tráquea parece ser un parámetro válido de la respuesta bronquial mediante el test de metacolina (TMCh). Objetivo: Evaluar la concordancia entre la concentración de metacolina que produce un descenso del 20% del volumen espiratorio máximo al primer segundo (FEV1, PC20) y PCw en el TMCh en niños asmáticos colaboradores. Pacientes y métodos: Se estudian 18 niños asmáticos de edad media 11,5 (límites, 6-16) años, 15/18 en tratamiento con glucocorticoides inhalados. Se realizó el TMCh según las normas de la American Thoracic Society (ATS) (1999) utilizando un nebulizador Hudson calibrado para obtener un débito de 0,14 ml/min. Tras cada nebulización, dos observadores independientes registraron el FEV1 y la auscultación traqueal. El FEV1 se determinó mediante espirometría forzada a los 30 y 90 s posnebulización y la PC20 por interpolación exponencial. Se monitorizaron de forma continua la frecuencia respiratoria y la saturación transcutánea de oxígeno. La tráquea se auscultó los 0, 60 y 120 s posnebulización. La prueba se consideró positiva al auscultar sibilancias sobre la tráquea. Se compararon los valores de PC20 y PCw, así como la concentración de metacolina correspondiente al descenso del FEV1 igual o superior al 20% con la PCw, mediante el test de la t de Student pareada y la prueba de Wilcoxon, y el grado de acuerdo de dichas variables con el test de Bland-Altman. Resultados: El TMCh fue positivo en 17/18 pacientes, sin diferencias entre PC20 y PCw (p 0,15). Ambos parámetros coincidieron en 12/17 casos. Hay una asociación evidente entre ambas medidas (log PCw, log PC20): R, 0,92; p < 0,001. El descenso medio del FEV1 al alcanzar la PCw fue del 24,8% (rango, 10-41). No se objetivaron efectos adversos en ningún caso. Conclusión: La concordancia entre PCw y PC20 en el TMCh en niños asmáticos colaboradores es excelente, y la PCw podría evaluar la hiperreactividad bronquial en el niño no colaborador (AU)