Alveolar nitric oxide and its role in pediatric asthma control assessment.

BACKGROUND: Nitric oxide can be measured at multiple flow rates to determine proximal (maximum airway nitric oxide flux; JawNO) and distal inflammation (alveolar nitric oxide concentration; CANO). The main aim was to study the association among symptoms, lung function, proximal (maximum airway nitric oxide flux) and distal (alveolar nitric oxide concentration) airway inflammation in asthmatic children treated and not treated with inhaled glucocorticoids. METHODS: A cross-sectional study with prospective data collection was carried out in a consecutive sample of girls and boys aged between 6 and 16 years with a medical diagnosis of asthma. Maximum airway nitric oxide flux and alveolar nitric oxide concentration were calculated according to the two-compartment model. In asthmatic patients, the asthma control questionnaire (CAN) was completed and forced spirometry was performed. In controls, differences between the sexes in alveolar nitric oxide concentration and maximum airway nitric oxide flux and their correlation with height were studied. The correlation among the fraction of exhaled NO at 50 ml/s (FENO50), CANO, JawNO, forced expiratory volume in 1 second (FEV1) and the CAN questionnaire was measured and the degree of agreement regarding asthma control assessment was studied using Cohen's kappa. RESULTS: We studied 162 children; 49 healthy (group 1), 23 asthmatic participants without treatment (group 2) and 80 asthmatic patients treated with inhaled corticosteroids (group 3). CANO (ppb) was 2.2 (0.1-4.5), 3 (0.2-9.2) and 2.45 (0.1-24), respectively. JawNO (pl/s) was 516 (98.3-1470), 2356.67 (120-6110) and 1426 (156-11805), respectively. There was a strong association (r=0.97) between FENO50 and JawNO and the degree of agreement was very good in group 2 and was good in group 3. There was no agreement or only slight agreement between the measures used to monitor asthma control (FEV1, CAN questionnaire, CANO and JawNO). CONCLUSIONS: The results for CANO and JawNO in controls were similar to those found in other reports. There was no agreement or only slight agreement among the three measure instruments analyzed to assess asthma control. In our sample, no additional information was provided by CANO and JawNO.

Young infants with recurrent wheezing and positive asthma predictive index have higher levels of exhaled nitric oxide.

OBJECTIVE: The aim of this post hoc analysis was to establish the relationship between FE(NO) levels and the asthma predictive index (API) among infants with recurrent wheezing. METHODS: Infants with recurrent wheezing (three or more episodes) were recruited consecutively and online FE(NO) tests at tidal breathing with multiple breaths were performed. RESULTS: Twenty-seven (84%) out of 32 infants (median age of 12 months) who met the inclusion criteria for this post hoc analysis, successfully performed the FE(NO) determinations. Eighteen (66%) infants were classified with positive stringent API. FE(NO) levels were significantly higher among patients with positive API than those with negative (median [IQR] of 12.3 [14.8] ppb vs. 4.1 [7.9] ppb, respectively, p = .016). Furthermore, FE(NO) and positive API had a significant correlation (Spearman's rho, ρ = 0.4741, p = .0125). After logistic regression analysis including FE(NO) levels, gender, age, and use of controller therapy, FE(NO) was the only variable that was marginally related to API (OR = 1.12, 95% CI: 0.99-1.27, p = .07). CONCLUSION: Infants with recurrent wheezing who had a positive stringent API already had higher FE(NO) levels than those with a negative API. This finding needs to be corroborated in a larger prospective study.

Concordancia en niños entre las resistencias de la vía aérea medidas mediante pletismografía con y sin cierre del oclusor / Differences in Airway Resistances in Children Measured by Plethysmography With and Without Closure of the Occluder

AntecedentesDiversos investigadores han estudiado las resistencias de la vía aérea mediante pletismografía sin cierre del oclusor.ObjetivoComprobar la concordancia entre las resistencias totales (sRawTOT) y las resistencias específicas (sRaw) con la misma técnica (pletismografía) y diferente metodología (con y sin cierre del oclusor) en niños colaboradores.Material y MétodosEstudio observacional y transversal de una muestra consecutiva de niños entre 6 y 14 años que acudieron a consultas de Neumología Infantil, desde el 15 de enero hasta el 15 de febrero de 2009. Determinación de sRawTOT, sRaw y conductancia específica (sGaw) mediante pletismografía (MasterLab V5.1, Viasys®, Wuerzburg, Alemania) sin cierre del oclusor. En todos se realizaron a continuación las mismas determinaciones con cierre del oclusor. Variables cualitativas: sexo, diagnóstico y tratamiento, y variables cuantitativas: edad, peso, talla, sRawTOT, sRaw, sGaw y FRcon y sin cierre del oclusor. Análisis de la asociación y concordancia entre sRawTOT, sRaw y sGaw con y sin cierre del oclusor mediante t de Student pareada, método Bland-Altman y diagrama de puntos (Scatter plot).ResultadosSe incluyeron 36 casos. El 100% realizó las pruebas con éxito. Edad media: 9,91±2,37 años. No hubo diferencias entre sRawTOT, sRaw ni sGaw con y sin cierre del oclusor. Tampoco hubo diferencias entre la regresión de las medias obtenidas de sRawTOT, sRaw y sGaw con y sin cierre del oclusor, respecto a la diferencia de las mismas.ConclusionesExiste una buena concordancia entre sRawTOT y sRaw obtenidas por pletismografía con y sin cierre del oclusor(AU)

BackgroundThere have been several studies that have measured airway resistances using plethysmography without closing the occluderObjectiveTo investigate the differences between the total resistances (sRawTOT) and the specific resistances (sRaw) with the same technique (plethysmography) but different methodology (with and without closure of the occluder) in child subjects.Material and MethodsAn observational and cross-sectional study of a consecutive sample of children between 6 and 14 years old who were seen at the Childhood Pneumology clinics from 15th January to 15th February 2009. Determination of sRawTOT, sRaw and specific conductance (sGaw) using plethysmography (MasterLab V5.1, Viasys®, Wuerzburg, Germany) without closing the occluder. The same determinations were then performed with the occluder closed. The qualitative variables were: sex, diagnosis and treatment, and the quantitative variables: age, weight, height, sRawTOT, sRaw, sGaw and respiratory rate with and without closing the occluder. The results were analysed for association and concordance between sRawTOT, sRaw and sGaw with and without closure of the occluder using paired Student t test, Bland-Altman method and a scatter plot.ResultsThirty-six cases were included and all (100%) the tests were performed successfully. The mean age was 9.91±2.37 years. There were no differences between sRawTOT, sRaw or sGaw with and without closure of the occluder. Neither were there any differences between the regression of the means obtained for sRawTOT, sRaw and sGaw with and without closure of the occluder.ConclusionsThere is good agreement between the sRawTOT y sRaw obtained by plethysmography with and without closure of the occluder(AU)

[Differences in airway resistances in children measured by plethysmography with and without closure of the occluder]. / Concordancia en niños entre las resistencias de la vía aérea medidas mediante pletismografía con y sin cierre del oclusor.

BACKGROUND: There have been several studies that have measured airway resistances using plethysmography without closing the occluder. OBJECTIVE: To investigate the differences between the total resistances (sRaw(TOT)) and the specific resistances (sRaw) with the same technique (plethysmography) but different methodology (with and without closure of the occluder) in child subjects. MATERIAL AND METHODS: An observational and cross-sectional study of a consecutive sample of children between 6 and 14 years old who were seen at the Childhood Pneumology clinics from 15th January to 15th February 2009. Determination of sRaw(TOT), sRaw and specific conductance (sGaw) using plethysmography (MasterLab V5.1, Viasys, Wuerzburg, Germany) without closing the occluder. The same determinations were then performed with the occluder closed. The qualitative variables were: sex, diagnosis and treatment, and the quantitative variables: age, weight, height, sRaw(TOT), sRaw, sGaw and respiratory rate with and without closing the occluder. The results were analysed for association and concordance between sRaw(TOT), sRaw and sGaw with and without closure of the occluder using paired Student t test, Bland-Altman method and a scatter plot. RESULTS: Thirty-six cases were included and all (100%) the tests were performed successfully. The mean age was 9.91+/-2.37 years. There were no differences between sRawTOT, sRaw or sGaw with and without closure of the occluder. Neither were there any differences between the regression of the means obtained for sRaw(TOT), sRaw and sGaw with and without closure of the occluder. CONCLUSIONS: There is good agreement between the sRaw(TOT) y sRaw obtained by plethysmography with and without closure of the occluder.

[The shuttle run test is not valid for the detection of asthma in school physical education programs]. / La prueba course-navette no es válida para detectar asma en programas de educación física escolar.

OBJECTIVE: Certain sporting activities may trigger asthma exacerbations of varying intensity in children. Such exacerbations may lead to limitations in and rejection of such activities. During school hours, teachers are in a good position to observe these phenomena. The aim of the present study was to evaluate the shuttle run, a test of physical fitness used in school physical education programs, as a way of detecting asthma. PATIENTS AND METHODS: We carried out a cross-sectional observational study of school children between the ages of 6 and 12 years using the asthma symptom questionnaire of the International Study of Asthma and Allergies in Childhood (ISAAC), a shuttle run test, and a free running test at maximum effort in order to study bronchial hyperresponsiveness. The principal measure of bronchial hyperresponsiveness used in both physical fitness tests was peak expiratory flow rate as measured with a peak flow meter. In comparing the results of the shuttle run test with those of the free running test and the ISAAC questionnaire we used the chi(2) test to measure association and the Cohen kappa coefficient to measure agreement. RESULTS: We distributed the ISAAC questionnaire (n=919) to 460 (50.1%) boys and 459 (49.9%) girls between the ages of 6 and 12 years. All the tests were completed by 826 children. The level of agreement between the shuttle run test and free running test was positive but low for decreases in peak expiratory flow rate compared to baseline of 15% (chi(2)=5.6; P< .05; kappa=0.093; SE, 0.042) and of 20% (chi(2)=4.5; P< .05; kappa=0.08; SE, 0.046). For 10% decreases association was not significant and agreement was low (kappa=0.05; SE, 0.04). There was no agreement between the ISAAC questionnaire and the shuttle run test (kappa=0.095; SE, 0.63). CONCLUSIONS: The shuttle run test using peak expiratory flow rate as the principal measure of bronchial hyperresponsiveness is not valid for the detection of asthma in schoolchildren.

[Obstructive sleep apnea-hypopnea syndrome in children is not associated with obesity]. / El síndrome de apneas-hipopneas obstructivas durante el sueño en niños no se asocia a obesidad.

OBJECTIVE: The prevalence of obstructive sleep apnea-hypopnea syndrome (OSAHS) in the general pediatric population ranges from 1% to 3%. However, its prevalence in an unselected population of obese children is unknown. We studied the association between obesity and OSAHS in children diagnosed with the syndrome in a cohort of boys and girls (age range, 2-14 years) referred to the pediatric respiratory medicine outpatient clinic at our hospital for suspected apnea, snoring, or both over the past 5 years. PATIENTS AND METHODS: The medical history of each patient was recorded and all patients underwent a physical examination, chest and nasal cavities radiography, and 8-channel respiratory polygraphy during sleep. The following variables were evaluated: sex, reason for consultation, source of referral, findings during upper airway examination, age, weight z-score (reflecting how much a finding differs from the mean and in what direction in a normally distributed sample), height z-score, body mass index (BMI) z-score, number of apneas, number of hypopneas, apnea index, hypopnea index, apnea-hypopnea index (AHI), oxygen saturation (mean and minimum) measured by pulse oximetry, number of snores, and snore index. RESULTS: Of the 400 patients studied, 242 (60.5%) were male and 158 (39.5%) female. The mean age was 4.95 years. OSAHS (AHI> or =3) was diagnosed in 298 cases (74.5%) and these patients were then studied to determine the relation between OSAHS and obesity. The anthropometric distribution (expressed as mean [SD]) was as follows: weight z-score, 0.37 (1.31); height z-score, 0.23 (1.19); BMI, 17.063 kg/m(2) (2.51); and BMI z-score, 0.39 (1.36). The respiratory polygraph during sleep recorded an AHI of 6.56 (7.56). CONCLUSIONS: No differences were observed between the height z-score, weight z-score, BMI z-score, age, and AHI. No association between obesity and OSAHS was found in this series. However, studies of larger, unselected populations are needed to determine if obesity is a risk factor for OSAHS in children.

La prueba course-navette no es válida para detectar asma en programas de educación física escolar / The shuttle run test is not valid for the detection of asthma in school physical education programs

Objetivo: Determinadas actividades deportivas pueden desencadenar en el niño agudizaciones de asma de intensidad variable, limitaciones y rechazo de las actividades deportivas. Durante el horario escolar los profesores son observadores privilegiados de estos fenómenos. El objetivo del presente estudio ha sido evaluar la prueba course-navette ("carrera de ida y vuelta", PCN), prueba de rendimiento físico de los programas de educación física escolar, como medida para detectar asma. Pacientes y métodos: Se ha realizado un estudio observacional y transversal en escolares de 6 a 12 años de edad, mediante cuestionario de síntomas relacionados con el asma (ISAAC) y pruebas de rendimiento físico (PCN) y de carrera libre con esfuerzo máximo para estudiar la hiperrespuesta bronquial, utilizando en ambas como medida principal el flujo espiratorio máximo (FEM) determinado con medidor del ápice de flujo espiratorio. En la comparación de los resultados de la PCN con los del test de carrera libre y el cuestionario ISAAC se midió el grado de asociación (con la prueba de la χ²) y de acuerdo (estadístico kappa de Cohen). Resultados: Se distribuyó el cuestionario ISAAC (n = 919) a 460 niños (50,1%) y 459 niñas (49,9%) de 6 a 12 años de edad (mediana ± desviación estándar: 8 ± 1,87 años). Completaron todas las pruebas 826. Se observó una asociación con bajo acuerdo entre la PCN positiva y el test de carrera libre positivo para descensos del FEM, en relación con el basal, del 15% χ² = 5,6; p < 0,05; kappa = 0,093; error estándar [EE] = 0,042) y del 20% (χ² = 4,5; p < 0,05; kappa = 0,08; EE = 0,046). Para descensos del FEM del 10% la asociación no fue significativa y el acuerdo resultó débil (kappa = 0,05; EE = 0,04). No hubo acuerdo entre ISAAC y la PCN (kappa = 0,095; EE = 0,63). Conclusiones: La PCN con el FEM como medida principal del efecto no es válida para detectar asma en escolares

Objective: Certain sporting activities may trigger asthma exacerbations of varying intensity in children. Such exacerbations may lead to limitations in and rejection of such activities. During school hours, teachers are in a good position to observe these phenomena. The aim of the present study was to evaluate the shuttle run, a test of physical fitness used in school physical education programs, as a way of detecting asthma. Patients and methods: We carried out a cross-sectional observational study of school children between the ages of 6 and 12 years using the asthma symptom questionnaire of the International Study of Asthma and Allergies in Childhood (ISAAC), a shuttle run test, and a free running test at maximum effort in order to study bronchial hyperresponsiveness. The principal measure of bronchial hyperresponsiveness used in both physical fitness tests was peak expiratory flow rate as measured with a peak flow meter. In comparing the results of the shuttle run test with those of the free running test and the ISAAC questionnaire we used the χ² test to measure association and the Cohen κ coefficient to measure agreement. Results: We distributed the ISAAC questionnaire (n=919) to 460 (50.1%) boys and 459 (49.9%) girls between the ages of 6 and 12 years. All the tests were completed by 826 children. The level of agreement between the shuttle run test and free running test was positive but low for decreases in peak expiratory flow rate compared to baseline of 15% (χ²=5.6; P<.05; κ=0.093; SE, 0.042) and of 20% (χ²=4.5; P<.05; κ=0.08; SE, 0.046). For 10% decreases association was not significant and agreement was low (κ=0.05; SE, 0.04). There was no agreement between the ISAAC questionnaire and the shuttle run test (κ=0.095; SE, 0.63). Conclusions: The shuttle run test using peak expiratory flow rate as the principal measure of bronchial hyperresponsiveness is not valid for the detection of asthma in schoolchildren

El síndrome de apneas-hipopneas obstructivas durante el sueño en niños no se asocia a obesidad / Obstructive sleep apnea-hypopnea syndrome in children is not associated with obesity

Objetivo: El síndrome de apneas-hipopneas obstructivas durante el sueño (SAHOS) alcanza una prevalencia del 1-3% en población general infantil. Sin embargo, en población obesa no preseleccionada la prevalencia es desconocida. Para estudiar la asociación entre SAHOS y obesidad en niños diagnosticados de dicho trastorno, hemos analizado a una cohorte de niños y niñas (2-14 años) remitidos en los últimos 5 años a consulta externas de neumología infantil por sospecha de apneas durante el sueño, ronquido o ambos. Pacientes y métodos: A los pacientes incluidos se les realizaron anamnesis, exploración física, radiografía de tórax y cávum y poligrafía respiratoria durante el sueño con 8 canales. Se analizaron las siguientes variables: sexo, motivo de consulta, procedencia, exploración de la vía aérea superior, edad, z-score del peso (cuánto se desvía la media de peso y en qué dirección respecto de la media de peso de una distribución normal), z-score de la talla (cuánto se desvía la media de la talla y en qué dirección respecto de la media de la talla de una distribución normal), z-score del índice de masa corporal (IMC; cuánto se desvía la media del IMC y en qué dirección respecto de la media del IMC de una distribución normal), número de apneas, número de hipopneas, índice de apneas/h, índice de hipopneas/h, índice de apneas-hipopneas/h (IAH/h), saturación de oxígeno por pulsioximetría (media y mínima), número de ronquidos e índice de ronquidos/h. Resultados: Se estudió a 400 pacientes, con una edad media de 4,95 años, de los que 242 eran varones (60,5%) y 158 niñas (39,5%). Se diagnosticó de SAHOS (IAH/h ≥ 3) a 298 (74,5%), y en éstos se analizó la relación entre SAHOS y obesidad. La distribución antropométrica (expresada en media ± desviación estándar) fue la siguiente: z-peso de 0,37 ± 1,31; z-talla de 0,23 ± 1,19; IMC de 17,063 ± 2,51 kg/m², y z-IMC de 0,39 ± 1,36. Los resultados de la poligrafía respiratoria durante el sueño mostraron un IAH/h de 6,56 ± 7,56. Conclusiones: No se han encontrado diferencias entre z-talla, z-peso, z-IMC, edad e IAH/h. En esta serie la obesidad no se asocia a SAHOS. Sin embargo, se requieren estudios en poblaciones más amplias y no preseleccionadas para evaluar si la obesidad actúa o no como factor de riesgo para desarrollar SAHOS en niños

Objective: The prevalence of obstructive sleep apnea-hypopnea syndrome (OSAHS) in the general pediatric population ranges from 1% to 3%. However, its prevalence in an unselected population of obese children is unknown. We studied the association between obesity and OSAHS in children diagnosed with the syndrome in a cohort of boys and girls (age range, 2-14 years) referred to the pediatric respiratory medicine outpatient clinic at our hospital for suspected apnea, snoring, or both over the past 5 years. Patients and methods: The medical history of each patient was recorded and all patients underwent a physical examination, chest and nasal cavities radiography, and 8-channel respiratory polygraphy during sleep. The following variables were evaluated: sex, reason for consultation, source of referral, findings during upper airway examination, age, weight z-score (reflecting how much a finding differs from the mean and in what direction in a normally distributed sample), height z-score, body mass index (BMI) z-score, number of apneas, number of hypopneas, apnea index, hypopnea index, apnea-hypopnea index (AHI), oxygen saturation (mean and minimum) measured by pulse oximetry, number of snores, and snore index. Results: Of the 400 patients studied, 242 (60.5%) were male and 157 (39.5%) female. The mean age was 4.95 years. OSAHS (AHI≥3) was diagnosed in 298 cases (74.5%) and these patients were then studied to determine the relation between OSAHS and obesity. The anthropometric distribution (expressed as mean [SD]) was as follows: weight z-score, 0.38 (1.31); height z-score, 0.23 (1.19); BMI, 17.063 kg/m² (2.51); and BMI z-score, 0.39 (1.36). The respiratory polygraph during sleep recorded an AHI of 6.56 (7.56). Conclusions: No differences were observed between the height z-score, weight z-score, BMI z-score, age, and AHI. No association between obesity and OSAHS was found in this series. However, studies of larger, unselected populations are needed to determine if obesity is a risk factor for OSAHS in children