Respiratory system parameters in children with low severity cystic fibrosis: is there early involvement in relation to healthy peers? / Parâmetros do sistema respiratório em crianças com fibrose cística de baixa gravidade: há acometimento precoce em relação a pares saudáveis?

ABSTRACT Objective: To compare and analyze pulmonary function and respiratory mechanics parameters between healthy children and children with cystic fibrosis. Methods: This cross-sectional analytical study included healthy children (HSG) and children with cystic fibrosis (CFG), aged 6-13 years, from teaching institutions and a reference center for cystic fibrosis in Florianópolis/SC, Brazil. The patients were paired by age and sex. Initially, an anthropometric evaluation was undertaken to pair the sample characteristics in both groups; the medical records of CFG were consulted for bacterial colonization, genotype, and disease severity (Schwachman-Doershuk Score — SDS) data. Spirometry and impulse oscillometry were used to assess pulmonary function. Results: In total, 110 children were included, 55 in each group. In the CFG group, 58.2% were classified as excellent by SDS, 49.1% showed the ΔF508 heterozygotic genotype, and 67.3% were colonized by some pathogens. Statistical analysis revealed significant differences between both groups (p<0.05) in most pulmonary function parameters and respiratory mechanics. Conclusions: Children with cystic fibrosis showed obstructive ventilatory disorders and compromised peripheral airways compared with healthy children. These findings reinforce the early changes in pulmonary function and mechanics associated with this disease.

RESUMO Objetivo: Comparar e analisar parâmetros de função pulmonar e de mecânica respiratória entre escolares saudáveis e com fibrose cística (FC). Métodos: Estudo transversal que incluiu escolares saudáveis (GES) e com FC (GFC), com idades entre seis e 13 anos, provenientes de instituições de ensino e de um centro de referência da FC em Florianópolis/SC, Brasil, pareados por idade e sexo, respectivamente. Inicialmente, conduziu-se avaliação antropométrica para pareamento e caracterização de ambos os grupos e, no GFC, consultou-se prontuário médico para registro dos dados de colonização bacteriana, genótipo e gravidade da doença (Escore de Schwachman-Doershuk — ESD). Para a avaliação da função pulmonar, realizou-se espirometria e a avaliação da mecânica respiratória foi conduzida por meio do sistema de oscilometria de impulso. Resultados: Participaram 110 escolares, 55 em cada grupo. No GFC, 58,2% foram classificados pelo ESD como excelentes, 49,1% apresentaram genótipo ∆F508 heterozigoto e 67,3% eram colonizados por alguma patógeno. Houve diferença significativa (p<0,05) na maioria dos parâmetros de função pulmonar e de mecânica respiratória entre os grupos. Conclusões: Escolares com FC apresentaram distúrbio ventilatório obstrutivo e com comprometimento de vias aéreas periféricas, em comparação aos escolares hígidos. Esse evento reforça o início precoce da alteração de função pulmonar e de mecânica respiratória nessa enfermidade, evidenciados pelos achados desta investigação.

Lung Function Tests in Infants and Children

Lung function testing is an essential modality of investigation in children as it provides objective evidence of lung disease/ health. With advances in technology, various tests are available that can aid in the diagnosis of lung disease, assess the progression and response to therapy and document the lung development and evolving lung diseases in infants. This narrative review discusses lung function tests in infants and children. Currently, lung function tests can be performed in every age group, from neonates to the elderly. Spirometry and peak expiratory flow rate (PEFR) are the most employed tests in children more than six years of age. Spirometry helps diagnose and monitoring of both obstructive and restrictive diseases. There is a need for expertise to perform and interpret spirometry correctly. The forced oscillation technique (FOT) or impulse oscillometry (IOS) is done with tidal volume breathing and is feasible even in preschool children. Their utility is mainly restricted to asthma in children at present. Lung function tests can be performed in neonates, infants and children using infant pulmonary function test (PFT) equipment, although their availability is limited. Diffusion capacity for carbon monoxide (DLCO) is a valuable tool in restrictive lung diseases. Lung volumes can be assessed by body plethysmography and multiple washout technique. The latter can also assess lung clearance index. It is essential to perform and interpret the lung function test results correctly and correlate them with the clinical condition for optimum treatment and outcome.

Relation of impulse oscillometry and spirometry with quantitative thorax computed tomography after COVID-19 pneumonia

SUMMARY OBJECTIVE: This study aimed to investigate if there is any correlation between the quantitative computed tomography and the impulse oscillometry or spirometry results of post-COVID-19 patients. METHODS: The study comprised 47 post-COVID-19 patients who had spirometry, impulse oscillometry, and high-resolution computed tomography examinations at the same time. The study group consisted of 33 patients with quantitative computed tomography involvement, while the control group included 14 patients who did not have CT findings. The quantitative computed tomography technology was used to calculate percentages of density range volumes. The relationship between percentages of density range volumes for different quantitative computed tomography density ranges and impulse oscillometry-spirometry findings was statistically analyzed. RESULTS: In quantitative computed tomography, the percentage of relatively high-density lung parenchyma, including fibrotic areas, was 1.76±0.43 and 5.65±3.73 in the control and study groups, respectively. The percentages of primarily ground-glass parenchyma areas were found to be 7.60±2.86 and 29.25±16.50 in the control and study groups, respectively. In the correlation analysis, the forced vital capacity% predicted in the study group was correlated with DRV%[(-750)-(-500)] (volume of the lung parenchyma that has density between (-750)-(-500) Hounsfield units), but no correlation with DRV%[(-500)-0] was detected. Also, reactance area and resonant frequency were correlated with DRV%[(-750)-(-500)], while X5 was correlated with both DRV%[(-500)-0] and DRV%[(-750)-(-500)] density. Modified Medical Research Council score was correlated with predicted percentages of forced vital capacity and X5. CONCLUSION: After COVID-19, forced vital capacity, reactance area, resonant frequency, and X5 correlated with the percentages of density range volumes of ground-glass opacity areas in the quantitative computed tomography. X5 was the only parameter correlated with density ranges consistent with both ground-glass opacity and fibrosis. Furthermore, the percentages of forced vital capacity and X5 were shown to be associated with the perception of dyspnea.

Comparison of impulse oscillometry and pulmonary function test in assessment of bronchial asthma control in children / 中华实用儿科临床杂志

Objective:To compare and analyze the effects of impulse oscillometry (IOS) and pulmonary function test (PFT) in the assessment of asthma control in children.Methods:A cross-sectional study of 323 children with bronchial asthma who visited the outpatient pediatric clinic of Shandong Provincial Hospital Affiliated to Shandong First Medical University from March to December 2020 was conducted.The patients were divided into the control group (123 cases) and the uncontrolled group (200 cases) according to the Childhood Asthma Control Test (C-ACT) score.In both groups, PFT and IOS were performed.The PFT test included the forced expiratory volume in one second (FEV 1), force expiratory volume in one second/forced vital capacity (FEV 1/FVC), peak expiratory flow (PEF), the instantaneous forced expiratory flow at 50% of forced vital capacity (FEF 50), the instantaneous forced expiratory flow at 75% of forced vital capacity (FEF 75), and maximum mid expiratory flow (MMEF). In the IOS test, the total respiratory impedance at 5 Hz (Z5), respiratory resistance at 5 Hz (R5), respiratory resistance at 20 Hz (R20), reactance at 5 Hz (X5), respiratory resistance at 5 Hz-respiratory resistance at 20 Hz (R5-R20), reactance area (AX), and resonance frequency (Fres) were measured.The data obtained were analyzed statistically using SPSS 25.0 software. ANOVA or Mann- Whitney U rank-sum test was used to compare data between groups.Receiver′s operating characteristic (ROC) curves were drawn to determine the predictive value of PFT and IOS parameters for uncontrolled asthma. Results:(1) According to the comparison results of PFT indexes between the two groups of children with asthma, the levels of FEV 1, FEV 1/FVC, PEF, FEF 50, FEF 75, MMEF in the control group were all higher than those in the uncontrolled group [(104.41±12.38)% vs.(98.89±16.61)%, 100.50 (94.40, 103.50)% vs.96.00 (89.83, 101.88)%, (100.29±15.31)% vs.(93.19±18.43)%, 85.60(70.60, 96.60)% vs.72.35 (57.08, 91.10)%, 67.20 (53.60, 81.70)% vs.56.80 (41.10, 74.73)%, 80.70 (66.80, 95.10)% vs.69.50 (54.03, 90.05)%] (all P<0.01). (2) According to the comparison results of IOS indices between the two groups, the levels of Z5, R5, R20, R5-R20, X5, AX and Fres in the control group were lower than those in the uncontrolled group {68.58 (63.29, 77.43)% vs.81.27(70.93, 91.96)%, 68.91(62.94, 77.60)% vs.80.61 (70.02, 89.29)%, 75.78 (67.50, 87.55)% vs.82.97 (71.50, 95.50)%, 0.51 (0.43, 0.59) [kPa/(L·S)] vs.0.62 (0.53, 0.74) [kPa/(L·S)], 69.31 (59.93, 79.14)% vs.86.48 (70.00, 102.48)%, 1.11 (0.76, 1.60) kPa/L vs.2.14 (1.42, 2.85) kPa/L, 18.21 (16.06, 19.56) Hz vs.20.56 (18.92, 22.81) Hz} (all P<0.01). (3) In the control group, 31 children (25.20%) had pulmonary dysfunction.(4) In the uncontrolled group, 95 children (47.50%) had pulmonary ventilation dysfunction.Only 20 children (10.00%) had a R5 larger than 120% of the predicted value and/or a R20 larger than 120% of the predicted value.(5) According to the ROC analysis results of the IOS indices for predicting asthma exacerbations, all of the areas under the ROC (AUC) of Z5, R5, R5-R20, X5, AX and Fres were greater than 0.7.AX had the highest value in predicting asthma exacerbations (AUC=0.785, 95% CI: 0.735-0.835), with sensitivity of 78.50% and specificity of 64.20%.All of the AUCs of PFT indices were smaller than 0.7.FEF 50 and MMEF had the largest AUC. Conclusions:PFT and IOS have good sensitivity in evaluating the level of asthma control in children, and IOS has good value in predicting asthma exacerbations.AX has the highest predictive value for asthma exacerbations.Asthma control levels of children should be evaluated using not only subjective (such as C-ACT score) but also objective (e.g.PFT, IOS) indices.

Respiratory oscillometry and functional analyses in patients with idiopathic scoliosis

Scoliosis is a condition that affects the spine and causes chest rotation and trunk distortion. Individuals with severe deformities may experience dyspnea on exertion and develop respiratory failure. Respiratory oscillometry is a simple and non-invasive method that provides detailed information on lung mechanics. This work aims to investigate the potential of oscillometry in the evaluation of respiratory mechanics in patients with scoliosis and its association with physical performance. We analyzed 32 volunteers in the control group and 32 in the scoliosis group. The volunteers underwent traditional pulmonary function tests, oscillometry, and the 6-minute walk test (6MWT). Oscillometric analysis showed increased values of resistance at 4 Hz (R4, P<0.01), 12 Hz (R12, P<0.0001), and 20 Hz (R20, P<0.01). Similar analysis showed reductions in dynamic compliance (Cdyn, P<0.001) and ventilation homogeneity, as evaluated by resonance frequency (fr, P<0.001) and reactance area (Ax, P<0.001). Respiratory work, described by the impedance modulus, also showed increased values (Z4, P<0.01). Functional capacity was reduced in the group with scoliosis (P<0.001). A significant direct correlation was found between Cobb angle and R12, AX, and Z4 (P=0.0237, P=0.0338, and P=0.0147, respectively), and an inverse correlation was found between Cdyn and Cobb angle (P=0.0190). These results provided new information on respiratory mechanics in scoliosis and are consistent with the involved pathophysiology, suggesting that oscillometry may improve lung function tests for patients with scoliosis.

Trayectorias de función pulmonar en asma persistente: del preescolar al escolar / Lung function trajectories in persistent asthma: from preschool to schoolchildren

Introducción: Se han informado patrones de deterioro temprano de la función pulmonar en el asma pediátrica. Nuestro objetivo fue identificar las trayectorias de la función pulmonar en la espirometría, desde la edad preescolar hasta la edad escolar. Materiales: Estudio prospectivo realizado entre el 2016 y el 2021. Se reclutaron pacientes con asma persistente a quienes se les realizó oscilometría de impulso (IOS)-espirometría al inicio y después de 3 años. La espirometría anormal se definió de acuerdo con las guías ATS/ERS. Métodos: se utilizó χ2 y ANOVA para comparar las características clínicas y promedios de parámetros de la espirometría e IOS entre trayectorias. Resultados: 86 pacientes, promedio de edad 5,3 y 8,3 años en su primera y segunda evaluación. El 70,9% de los pacientes mantuvo la espirometría normal en ambas evaluaciones (trayectoria 1), el 9,3% presentó espirometría preescolar anormal que normalizó en la edad escolar (trayectoria 2) y el 19,8% espirometría en anormal en ambas evaluaciones (trayectoria 3). La trayectoria 3 registró menor peso promedio al nacer (2,4 kg vs 3,02 kg p = 0,04), mayor promedio de exacerbaciones (5,3 vs 2,01 p = 0,00002), mayor promedio de hospitalizaciones (0,61 vs 0,16 p = 0,04), parámetros promedio más bajos en espirometría (relación VEF1/CVF %, relación VEF0,75/CVF %, VEF0,75 L, VEF0,5 L), promedios más bajos en X5 kPa/Ls y más altos en AX kPa/Ls, que la trayectoria 1. Conclusiones: La trayectoria 1 fue la más frecuente, con persistencia de función pulmonar normal. La trayectoria 3, la segunda más frecuente, inició seguimiento con función pulmonar disminuida en la espirometría y disfunción de vía aérea pequeña en el IOS que se mantuvo en la edad escolar. Los niños que siguieron la trayectoria 3 tuvieron menor peso al nacer, más exacerbaciones y hospitalizaciones que los niños de la trayectoria 1.

Introduction: Patterns of early decline in lung function have been reported in pediatric asthma. Our objective was to identify pulmonary function trajectories in spirometry, from preschool age to school age. Materials: Prospective study conducted between 2016 and 2021. Patients with persistent asthma who underwent impulse oscillometry (IOS)-spirometry at baseline and after 3 years were recruited. Abnormal spirometry was defined according to ATS/ERS guidelines. Methods: χ2 and ANOVA was used to compare clinics characteristics and means of IOS-spirometry parameters between trajectories. Results: 86 patients, mean age of 5,3 and 8,3 years in their first and second evaluation. 70.9% of the patients maintained normal spirometry in both evaluations (Track 1), 9.3% presented abnormal preschool spirometry that normalized at school age (Track 2) and 19.8% abnormal spirometry in both evaluations (Track 3). Trajectory 3 had a lower average birth weight (2,4 kg vs 3,02 kg p = 0,04), higher average of exacerbations (5,3 vs 2,01 p = 0,00002), higher average of hospitalizations (0,61 vs 0,16 p = 0,04), lowest averages parameters in spirometry (FEV1/FVC % ratio, FEV0,75/FVC % ratio, FEV0,75 L, FEV0,5 L), lower average in X5 kPa/Ls and higher in AX kPa/Ls, than trajectory 1. Conclusions: Trajectory 1 was the most common, with persistent normal lung function. Trajectory 3, the second most frequent, started follow-up with decreased lung function in spirometry and small airway disfunction in the IOS that were maintained at school age. Children who followed trajectory 3 had lower birth weight, more exacerbations, and hospitalizations than children in trajectory 1.

Pulmonary function and medication effect in mild-stage subjects with Parkinson's disease / Função pulmonar e efeitos da medicação em pessoas com doença de Parkinson em estágio leve

Abstract Background Parkinson's disease (PD) causes a series of movement disorders, many of them starting in the early stage. Objective To analyze the pulmonary function of mild-stage subjects with PD and to investigate the effects of levodopa on it. Methods We included 21 patients with idiopathic PD and 20 healthy control subjects. The participants were submitted to spirometry and impulse oscillometry assessments. The PD patients were evaluated during the "off" and "on" phases of their anti-PD medication, which was was converted to levodopa in an equivalent daily dose. A statistical analysis was performed with cross-sectional (PD patients "off" medication versus controls) and paired (PD patients "off" medication versus PD patients "on" medication) tests. The effect of levodopa was calculated with partial Eta-squared (η2ρ). Significance was set at 5%. Results The PD patients presented normal values in the impulse oscillometry. Regarding spirometry, the results indicated an incipient obstructive ventilatory disorder in the PD group - confirmed by patients' flow-volume curves. The PD patients received a daily dose of 354.7 ± 148.2 mg of levodopa. The paired analyses showed a small effect of anti-PD medication on pulmonary parameters (η2ρ = 0.197 for spirometry and η2ρ = 0.043 for impulse oscillometry). Conclusion Patients with PD in the mild stage of the disease present pulmonary compliance and resistance compatible with normal parameters. The differences regarding the spirometric results indicate an incipient obstructive ventilatory disorder in patients with PD. Levodopa had small effect on pulmonary function in the mild stage of the disease.

Resumo Antecedentes A doença de Parkinson (DP) causa uma série de distúrbios do movimento, muitos deles se desenvolvendo na fase inicial. Objetivo Analisar função pulmonar de pessoas com DP em estágio leve e investigar o efeito da levodopa nesse processo. Métodos Vinte e um participantes com DP idiopática e vinte controles saudáveis foram incluídos na pesquisa. Todos os sujeitos foram submetidos a avaliações de espirometria e oscilometria de impulso. Participantes com DP foram avaliados nas fases 'on' e 'off' de medicação anti-parkinsoniana. A medicação dos pacientes foi convertida em dose diária de levodopa. A análise estatística foi realizada com testes transversais (Parkinson na fase 'off' da medicação vs controles) e pareados (Parkinson nas fases 'off' vs 'on' da medicação). O efeito da levodopa foi calculado pelo eta ao quadrado parcial (η2ρ). Significância foi estipulada em 5%. Resultados Pacientes com DP apresentaram valores normais na oscilometria de impulso. Na espirometria, os resultados indicaram uma desordem ventilatória obstrutiva incipiente no grupo DP - confirmada pelas curvas fluxo-volume dos pacientes. Pacientes com DP receberam uma dose diária de 354,7 ± 148,2 miligramas de levodopa. Análises pareadas mostraram baixo impacto da medicação anti-parkinsoniana nos parâmetros pulmonares (η2ρ = 0,197 na espirometria e η2ρ = 0,043 na oscilometria de impulso). Conclusão Pacientes com DP na fase leve apresentam complacência e resistência pulmonares compatíveis com parâmetros normais. Diferenças espirométricas indicam distúrbio ventilatório obstrutivo incipiente em pacientes com DP. A administração de levodopa apresentou baixo efeito na função pulmonar na fase leve da doença.

Evaluation of oscillometric blood pressure measurement devices available for online sale / Evaluación de los aparatos oscilométricos de medición de la presión sanguínea disponibles para comercialización en línea / Avaliação dos dispositivos oscilométricos de medida de pressão arterial disponíveis para comercialização on-line

ABSTRACT Objectives: to characterize oscillometric blood pressure measurement devices for sale in the virtual market and identify which ones have undergone a validation study. Methods: this was a cross sectional study. The search for devices for sale was conducted on websites, and the sample was composed of 137 devices obtained from 644 ads. We conducted a bibliographic survey in five databases and web pages enlisting devices submitted for validation. The Kolmogorov-Smirnov test was used to check data distribution, followed by Mann-Whitney and Kruskal-Wallis tests for comparisons, using the SAS 9.4 program. Results: only 16.7% of the devices were validated. The home devices ranged from USD 10.57 to USD 275.67. Only 102 ads informed the cuff size, with different nomenclatures. Conclusions: most ads contained non-validated devices, which were cheaper. We identified some ads falsely informing validation.

RESUMEN Objetivos: caracterizar aparatos oscilométricos de medición de la presión sanguínea a la venta en el mercado virtual e identificar cuales pasaron por estudio de validación. Métodos: discorre de un estudio transversal. La búsqueda de equipos a la venta fue realizada en páginas de internet, y la muestra fue composta por 137 equipos, obtenidos en 644 anuncios. Realizado levantamiento bibliográfico en cinco bases de datos y consultadas páginas de internet que registran equipos sometidos a validación. Utilizadas las pruebas Kolmogorov-Smirnov para verificación de la distribución de los datos, seguidos de Mann-Whitney y Kruskal-Wallis para comparaciones, mediante el programa SAS 9.4. Resultados: solamente 16,7% de los aparatos eran validados. Equipos domiciliares presentaron variancia de R$ 58,70 a R$ 1.531. Solo 102 anuncios informaron las dimensiones del brazalete, con nomenclaturas diferentes. Conclusiones: la mayoría de los anuncios contenía equipos no validados, que eran más baratos. Fueron identificados anuncios con informaciones falsas sobre validación.

RESUMO Objetivos: caracterizar os dispositivos oscilométricos de medida da pressão arterial à venda no mercado virtual e identificar quais passaram por estudo de validação. Métodos: trata-se de um estudo transversal. A busca dos aparelhos à venda foi realizada em páginas da internet, e a amostra foi composta por 137 aparelhos, obtidos em 644 anúncios. Foi realizado levantamento bibliográfico em cinco bases de dados e consultadas páginas da internet que registram aparelhos submetidos à validação. Utilizaram-se os testes Kolmogorov-Smirnov para verificação da distribuição dos dados, seguidos de Mann-Whitney e Kruskal-Wallis para comparações, por meio do programa SAS 9.4. Resultados: somente 16,7% dos dispositivos eram validados. Os aparelhos domiciliares apresentaram variação de R$ 58,70 a R$ 1.531. Apenas 102 anúncios informaram as dimensões da braçadeira, com nomenclaturas diferentes. Conclusões: a maioria dos anúncios continha aparelhos não validados, que eram mais baratos. Foram identificados anúncios com informações falsas sobre validação.

Función pulmonar oscilometría de impulso en pediatría: procedimiento y aplicación clínica / Pulmonary function impulse oscillometry in pediatrics: procedure and clinical application

La Oscilometría de Impulso (IOS) es una técnica no invasiva que evalúa las propiedades mecánicas de todo el sistema respiratorio durante la respiración tranquila. Mide la impedancia total del sistema respiratorio, evaluando la resistencia total de la vía aérea, la resistencia de la vía aérea alta y las propiedades elásticas del pulmón. Detecta el compromiso de la vía aérea periférica en forma muy precoz, antes que la espirometría, y es útil en niños pequeños porque no requiere maniobras de espiración forzada. Permite evaluar la respuesta broncodilatadora y broncoconstrictora a través de pruebas de provocación bronquial para el diagnóstico de hiperreactividad bronquial. La IOS tiene un rol en la evaluación temprana y seguimiento de la función pulmonar en niños con enfermedades respiratorias crónicas, principalmente asma bronquial, displasia broncopulmonar y fibrosis quística. Este artículo revisa los aspectos fisiológicos, técnicos y aplicación clínica de la IOS, considerando las últimas recomendaciones para la estandarización del examen y las limitaciones que dificultan su interpretación .

Impulse Oscillometry (IOS) is a non-invasive technique that assesses the mechanical properties of the entire respiratory system during quiet breathing. It measures the total impedance of the respiratory system by evaluating total airway resistance, upper airway resistance, and elastic properties of the lung. It detects peripheral airway compromise very early, before spirometry, and is useful in young children because it does not require forced expiration maneuvers. It allows evaluating the bronchodilator and bronchoconstrictor response through bronchial provocation tests for the diagnosis of bronchial hyperreactivity. The IOS has a role in the early evaluation and monitoring of lung function in children with chronic respiratory diseases, mainly bronchial asthma, bronchopulmonary dysplasia and cystic fibrosis. This article reviews the physiological, technical, and clinical application aspects, considering the latest recommendations for the standardization of the test and the limitations that hinder its interpretation.

Intra-breath oscillometry for the evaluation of lung function in children and adolescents with a history of preterm birth / Oscilometria intra-breath para avaliação da função pulmonar em crianças e adolescentes com história de prematuridade

ABSTRACT Objective: To assess respiratory system impedance (Zrs) and spirometric parameters in children and adolescents with and without a history of preterm birth. Methods: We evaluated a sample of 51 subjects between 11 and 14 years of age: 35 who had a history of preterm birth (preterm group) and 16 who had been born at term (full-term group). Lung function was measured by spirometry, spectral oscillometry, and intra-breath oscillometry. Results: Neither spirometry nor spectral oscillometry revealed any statistically significant differences between the preterm and full-term groups. However, intra-breath oscillometry demonstrated significant differences between the two groups in terms of the change in resistance, reactance at end-inspiration, and the change in reactance (p < 0.05 for all). Conclusions: Our findings suggest that abnormalities in Zrs persist in children and adolescents with a history of preterm birth and that intra-breath oscillometry is more sensitive than is spectral oscillometry. Larger studies are needed in order to validate these findings and to explore the impact that birth weight and gestational age at birth have on Zrs later in life.

RESUMO Objetivo: Avaliar a impedância do sistema respiratório (Zsr) e parâmetros espirométricos em crianças e adolescentes com e sem história de prematuridade. Métodos: Foi analisada uma amostra de 51 indivíduos entre 11 e 14 anos de idade: 35 com história de prematuridade (grupo pré-termo) e 16 nascidos a termo (grupo a termo). A função pulmonar foi medida por meio de espirometria, oscilometria espectral e oscilometria intra-breath. Resultados: A espirometria e a oscilometria espectral não revelaram diferenças estatisticamente significativas entre os grupos pré-termo e a termo. No entanto, a oscilometria intra-breath demonstrou diferenças significativas entre os dois grupos quanto à alteração da resistência, à reatância ao final da inspiração e à alteração da reatância (p < 0,05 para todas). Conclusões: Nossos achados sugerem que as anormalidades na Zsr persistem em crianças e adolescentes com história de prematuridade e que a oscilometria intra-breath é mais sensível do que a oscilometria espectral. São necessários estudos maiores para validar esses achados e para explorar o impacto do peso e idade gestacional ao nascer na Zsr mais tarde na vida.

The clinical application of impulse oscillometry in children with asthma / 国际儿科学杂志

Bronchial asthma is a common chronic respiratory disease in childhood.Lung function test is helpful for the diagnosis, treatment and dynamic monitoring of patients with asthma.Impulse oscillometry(IOS)has received more and more attention in the diagnosis and treatment of bronchial asthma because of its relatively simple operation requirements and the uniqueness of airway function detection.However, the clinical significance of IOS examination in clinical practice is not yet completely clear, and there is no consensus on clinical application.This article makes a review of IOS examination in the diagnosis, airway hyperreactivity test, asthma control and treatment of asthma in children, in order to help clinicians to make rational use of IOS examination.

Alteraciones de la función pulmonar medida por espirometría y oscilometría de impulso en niños asmáticos con sobrepeso y obesidad / Alterations in lung function as measured by spirometry and impulse oscillometry in asthmatic children with overweight and obesity

INTRODUCCIÓN: El incremento del índice de masa corporal afecta la función pulmonar en el asma. Objetivo: determinar si existen diferencias entre asmáticos con estado nutricional normal, sobrepeso y obesidad en cuanto a alteraciones de la oscilometría de impulso (IOS) y espirometría. MÉTODO: Estudio realizado en niños y adolescentes con asma persistente. Se practicó sucesivamente IOS y Espirometría pre y post- broncodilatador según criterios ATS/ERS/SER. Los pacientes se clasificaron en: eutróficos (AE), con sobrepeso (ASP) y obesos (AO). Se compararon promedios de valores basales y con respuesta broncodilatadora (RB) en espirometría e IOS, con análisis de varianzas ANOVA y test de Tukey post hoc. Se consideró un poder de 80% y error α de 5%. RESULTADOS: Se analizaron 559 pacientes, promedio de edad 9,2 años, 50,9% varones. AE 52,4%, ASP 31,3% y AO 16,3%. Se encontraron diferencias significativas entre AO vs AE (X5, AX, D5-20, VEF1/CVF, FEF25-75/CVF, RB VEF1), y entre ASP vs AE (AX, D5-20, VEF1/CVF). También se encontraron diferencias significativas en varones, no encontradas en las mujeres (X5, D5-20, VEF1/CVF, RB CVF, RB VEF1). CONCLUSIONES: Los niños asmáticos con sobrepeso y obesidad, tienen un mayor compromiso de los índices de función pulmonar medida por espirometría e IOS que los asmáticos con estado nutricional normal. Existen diferencias de género en las alteraciones espirometría e IOS.

INTRODUCTION: Increased body mass index asthma affects lung function in asthma. Objective: to determine if asthmatics with overweight or obesity have alterations in Impulse oscillometry (IOS) and spirometry compared to eutrophic METHOD: Study carried out in children and adolescents with persistent asthma. IOS-Spirometry pre and post bronchodilator were performed successively according to ATS/ERS/SER criteria. The patients were classified as: eutrophic (AE), overweight (ASP) and obese (OA). Baseline and bronchodilator response (BR) averages were compared in spirometry and IOS with ANOVA and Tukey's post hoc analysis of variance. A power of 80% and α error of 5% were considered. RESULTS: 559 patients were analyzed, mean age 9.2 years, 50.9% male. AE 52.4%, ASP 31.3% and OA 16.3%. Significant differences were found between OA vs AE (X5, AX, D5-20, FEV1/FVC, FEF25-75 / FVC, RB FEV1), and between ASP vs AE (AX, D5-20, FEV1/FVC). Significant differences were also found in men, not women (X5, D5-20, FEV1/FVC, BR FVC, BR FEV1). CONCLUSIONS: Asthmatic children with overweight and obesity have a greater compromise of pulmonary function parameters measured by spirometry and IOS than asthmatics with normal nutritional status. There are gender differences in spirometry and IOS alterations.

Carotid Intima and Media Thickness Correlation with Central Blood Pressure Measurements by Tonometric and Oscillometric Methods: A Proof of Concept

Abstract Background The early detection of vascular damage in subclinical stages of hypertensive disease may be the key point in the prevention of cardiovascular outcomes. Objectives to correlate parameters of structural vascular damage (measurement of the carotid intima-media thickness) with parameters of functional vascular damage (central hemodynamic measurements) in pre-hypertensive and hypertensive patients taking up to two classes of anti-hypertensive drugs. Methods This was a cross-sectional descriptive study conducted with a convenience sample of patients attending the Liga de Hipertensão Arterial , a multidisciplinary program for the diagnosis and treatment of systemic hypertension, of the Federal university of Goias. Patients with arrythmia, diabetes, previous cardiovascular or cerebrovascular diseases, and end-stage diseases were excluded. Carotid Doppler test, measurements of peripheral and central blood pressure by applanation tonometry (Sphygmocor®) and oscillometry (Mobil-O-Graph®) were performed. The t-test was used for comparisons and the Pearson correlation test for correlations, considering a p<0.05 statistically significant. Results twenty patients (12 women) were evaluated, mean age 53.8 ± 14.3 years. Higher values of central pulse pressure (42.9±13.9 vs. 34.7±9.6, p=0.01) and pulse wave velocity (PWV) (9.0±1.9 vs. 7.9±1.5, p=0.01) were obtained by applanation tonometry compared with oscillometry. No difference between the methods was observed for the other measures. A significant correlation was found between carotid artery intima-media thickness (CA-IMT) and PWV (r=0.659; p=0.002) by the oscillometric test, but not with applanation tonometry. No correlation was found between central hemodynamic variables and the presence of carotid artery plaques. Conclusion PWV, estimated by oscillometry, was the only central hemodynamic parameter that correlated significantly with CA-IMT in pre-hypertensive and hypertensive patients at low cardiovascular risk. International Journal of Cardiovascular Sciences. 2020; [online].ahead print, PP.0-0

Técnica de oscilações forçadas na avaliação e manejo de crianças asmáticas: uma revisão narrativa / Forced oscillation technique in the assessment and management of asthmatic children: a narrative review

Asthma is considered the most prevalent chronic disease in children. The pulmonary function measurements are important in the evaluation of the disease, being able to confirm the diagnosis by demonstrating the reversibility of the obstruction as well as detecting risks of poor prognosis in the control of asthma. However, the most common methods for analyzing pulmonary function in this age group have restrictions on its applicability, especially due to the need for cooperation on the part of patients. The forced oscillation technique (FOT) is considered a modern tool capable of estimating measures of respiratory mechanics related to the lungs. This method is easily applicable due to the low need for patient cooperation, an important element in the assessment of children. The aim of this study is to review the clinical utility of the Forced Oscillation Technique in the pulmonary assessment of asthmatic children. The bibliographic search covered the years between 1950 and 2019, in the databases: Medical Literature Analysis and Retrieval System Online (MEDLINE) and Latin American and Caribbean Literature in Health Sciences (LILACS). It was used as a search strategy the combination of the following Medical Subject Headings (MeSH) terms: "asthma", "oscillometry" and "child" crossed through the AND and OR Boolean connectors. In asthmatic children, FOT showed greater accuracy in the evaluation of smaller caliber peripheral airways, which can be applied as a complementary method to spirometry to strengthen the diagnosis, enabling a better understanding of the disease and its progression.

A asma é considerada a doença crônica de maior incidência em crianças. As medidas de função pulmonar são importantes na avaliação da doença, podendo confirmar o diagnóstico pela demonstração de reversibilidade da obstrução assim como detectar riscos de mau prognóstico no controle da asma. Entretanto, os métodos mais usuais para análise da função pulmonar nesta faixa etária apresentam restrições em sua aplicabilidade, especialmente pela necessidade de cooperação por parte dos pacientes. A técnica de oscilações forçadas (FOT) é considerada uma ferramenta moderna capaz de estimar medidas da mecânica respiratória relativas aos pulmões. Este método apresenta fácil aplicabilidade pela baixa necessidade de cooperação do paciente, elemento importante na avaliação de crianças. O objetivo deste estudo é revisar a utilidade clínica da Técnica de Oscilações Forçadas na avaliação pulmonar de crianças asmáticas. A busca bibliográfica contemplou os anos entre 1950 e 2019, nas bases de dados: Medical Literature Analysis and Retrieval System Online (MEDLINE) e Literatura Latino-Americana e do Caribe em Ciências da Saúde (LILACS). Foi utilizada como estratégia de busca a combinação dos seguintes Medical Subject Headings(MeSH) terms: "asthma", "oscillometry" e "child" cruzados por meio dos conectores booleanos AND e OR. Em crianças asmáticas, a FOT mostrou maior acurácia na avaliação de vias aéreas periféricas de menor calibre, podendo ser aplicada como método complementar a espirometria para encorpar o diagnóstico, possibilitando compreender melhor a doença e sua progressão.

Research progress in the application of impulse oscillometry and fractional exhaled nitric oxide in idiopathic pulmonary fibrosis / 中国医师杂志

Impulse oscillometry (IOS) and exhaled nitric oxide fraction determination (FeNO) are two detection methods to evaluate lung function, which can provide important functional information not captured in standardized lung function tests. These two methods may be promising disease assessment and detection tools for idiopathic pulmonary fibrosis (IPF). Therefore, it is necessary to standardize IOS and FeNO methods. This paper reviews the research progress of IOS and FeNO in IPF, and discusses the limitations of these two detection methods and their application value in IPF.

Do impulse oscillometry parameters differ between children and adolescents with symptoms of rhinitis and those without? / Há diferenças entre parâmetros de impulso oscilométricos de crianças e adolescentes com e sem sintomas de rinite?

ABSTRACT Objective: To compare impulse oscillometry parameters between healthy children and adolescents with symptoms of rhinitis and those without. Methods: This was a cross-sectional analytical study of healthy individuals 7-14 years of age. Health status was determined through the use of questionnaires. We performed anthropometric measurements, impulse oscillometry, and spirometry. Results: The sample comprised 62 students, with a mean age of 9.58 ± 2.08 years and a mean body mass index (BMI) of 17.96 ± 3.10 kg/m2. The students were divided into two groups: those with symptoms of rhinitis (n = 29) and those without such symptoms (n = 33). The oscillometry results and anthropometric parameters were normal in both groups and did not differ significantly between the two. The variables age, height, and body mass, respectively, correlated negatively and moderately with most of the following parameters: total airway resistance (r = −0.529, r = −0.548, and r = −0.433); central airway resistance (r = −0.441, r = −0.468, and r = −0.439); respiratory impedance (r = −0.549, r = −0.567, and r = −0.455); reactance at 5 Hz (r = 0.506, r = −0.525, and r = −0.414); reactance area (r = −0.459, r = −0.471, and r = −0.358); and resonance frequency (r = −0.353, r = −0.371, and r = −0.293). We found that BMI did not correlate significantly with any of the parameters evaluated. The same was true when we analyzed each group in isolation. Conclusions: In our sample, impulse oscillometry parameters did not differ between the students who had symptoms of rhinitis and those who did not.

RESUMO Objetivo: Comparar parâmetros de impulso oscilométricos em crianças e adolescentes saudáveis com e sem sintomas de rinite. Métodos: Estudo transversal analítico com indivíduos saudáveis com idade de 7-14 anos. A higidez foi determinada por meio de questionários, e foram realizadas medições antropométricas, oscilometria de impulso e espirometria. Resultados: A amostra total foi composta por 62 escolares (média de idade = 9,58 ± 2,08 anos e média de índice de massa corpórea (IMC) = 17,96 ± 3,10 kg/m2). A amostra total foi dividida em grupos com (n = 29) e sem sintomas de rinite (n = 33), que apresentaram resultados normais nos parâmetros oscilométricos e antropométricos, sem diferenças entre os grupos. As variáveis idade, estatura e massa corporal, respectivamente, correlacionaram-se, em sua grande maioria, negativa e moderadamente com os parâmetros resistência total das vias aéreas (r = −0,529; r = −0,548; e r = −0,433), resistência central das vias aéreas (r = −0,441; r = −0,468; e r = −0,439), impedância respiratória (r = −0,549; r = −0,567; e r = −0,455), reatância a 5 Hz (r = 0,506; r = −0,525; e r = −0,414), área de reatância (r = −0,459; r = −0,471; e r = −0,358) e frequência de ressonância (r = −0,353; r = −0,371; e r = −0,293). O IMC não se correlacionou significativamente com os parâmetros avaliados. O mesmo comportamento foi observado analisando-se os grupos isoladamente. Conclusões: Em nossa amostra, escolares que apresentam sintomas de rinite não apresentaram alterações nos parâmetros de impulso oscilométricos quando comparados àqueles sem esses sintomas.

Optimización del desempeño del observador al medir la presión arterial en el consultorio: declaración de posición de la Comisión Lancet de Hipertensión / Optimizing observer performance of clinic blood Pressure measurement: a position statement from the Lancet Commission on Hypertension Group / Otimização do desempenho do observador na medição clínica da pressão arterial: posicionamento do Grupo da Lancet Commission on Hypertension

RESUMEN La hipertensión arterial es una causa modificable muy prevalente de enfermedades cardiovasculares, accidentes cerebrovasculares y muerte. Medir con exactitud la presión arterial es fundamental, dado que un error de medición de 5 mmHg puede ser motivo para clasificar incorrectamente como hipertensas a 84 millones de personas en todo el mundo. En la presente declaración de posición se resumen los procedimientos para optimizar el desempeño del observador al medir la presión arterial en el consultorio, con atención especial a los entornos de ingresos bajos o medianos, donde esta medición se ve complicada por limitaciones de recursos y tiempo, sobrecarga de trabajo y falta de suministro eléctrico. Es posible reducir al mínimo muchos errores de medición con una preparación adecuada de los pacientes y el uso de técnicas estandarizadas. Para simplificar la medición y prevenir errores del observador, deben usarse tensiómetros semiautomáticos o automáticos de manguito validados, en lugar del método por auscultación. Pueden ayudar también la distribución de tareas, la creación de un área específica de medición y el uso de aparatos semiautomáticos o de carga solar. Es fundamental garantizar la capacitación inicial y periódica de los integrantes del equipo de salud. Debe considerarse la implementación de programas de certificación de bajo costo y fácilmente accesibles con el objetivo de mejorar la medición de la presión arterial.(AU)

ABSTRACT High blood pressure (BP) is a highly prevalent modifiable cause of cardiovascular disease, stroke, and death. Accurate BP measurement is critical, given that a 5-mmHg measurement error may lead to incorrect hypertension status classification in 84 million individuals worldwide. This position statement summarizes procedures for optimizing observer performance in clinic BP measurement, with special attention given to low-tomiddle- income settings, where resource limitations, heavy workloads, time constraints, and lack of electrical power make measurement more challenging. Many measurement errors can be minimized by appropriate patient preparation and standardized techniques. Validated semi-automated/automated upper arm cuff devices should be used instead of auscultation to simplify measurement and prevent observer error. Task sharing, creating a dedicated measurement workstation, and using semi-automated or solar-charged devices may help. Ensuring observer training, and periodic re-training, is critical. Low-cost, easily accessible certification programs should be considered to facilitate best BP measurement practice.(AU)

RESUMO A hipertensão é uma causa altamente prevalente de doença cardiovascular, acidente vascular cerebral e morte. A medição precisa da pressão arterial (PA) é um aspecto crítico, uma vez que erros de mensuração da ordem de 5 mmHg podem levar a uma classificação incorreta do status de hipertensão em 84 milhões de pessoas em todo o mundo. O presente posicionamento resume os procedimentos para otimizar o desempenho do observador (o indivíduo responsável pela mensuração da PA) na mensuração clínica da PA, com atenção especial para contextos de baixa a média renda, onde recursos limitados, cargas de trabalho pesadas, restrições de tempo e falta de energia elétrica tornam mais desafiadora a tarefa de medir a PA. Muitos erros de mensuração podem ser minimizados pela preparação adequada do paciente e pelo uso de técnicas padronizadas. Para simplificar a mensuração e evitar erros do observador, devem-se utilizar dispositivos semiautomatizados ou automatizados validados, com manguito para braço, ao invés de auscultação. O compartilhamento de tarefas, a criação de uma estação de trabalho dedicada à mensuração e o uso de dispositivos semiautomatizados ou com carga solar podem ajudar. É essencial que seja assegurado o treinamento e retreinamento periódico do observador. Programas de certificação de baixo custo e de fácil acesso devem ser considerados para facilitar a adoção das melhores práticas na mensuração da PA.(AU)

Cardiovascular Risk in Psoriasis Patients: Clinical, Functional and Morphological Parameters / Risco Cardiovascular em Pacientes Psoriásicos: Avaliação de Parâmetros Clínicos, Funcionais e Morfológicos

Abstract Background: Psoriasis correlates with metabolic disorders, early atheromatosis and increased cardiovascular risk. Objectives: To assess markers of cardiovascular disease in psoriatic patients. Methods: Cross-sectional, observational study involving 11 psoriatic participants and 33 controls. Anthropometric, biochemical, hemodynamic and imaging parameters were evaluated. Arterial stiffness was assessed by oscillometric measurement of the brachial artery. Intima-media thickness (IMT) and left ventricular diastolic function were assessed by Doppler echography and echocardiography. Between-group comparisons of numerical variables were performed by the Student's t-test or Wilcoxon Mann-Whitney test for independent samples. Significance level was set at 5%. Results: Psoriatic patients showed increased pulse wave velocity (PWV) (9.1 ± 1.8 vs 8.0 ± 2 m/s, p = 0.033), IMT of the left common carotid artery (p = 0.018) and a higher percentage of patients above the 75th percentile according to the ELSA table when compared with controls (54.5 vs 18.2%, p = 0.045). Psoriatic patients also showed an increase in peripheral/central systolic blood pressure (137.1 ± 13.2 vs 122.3 ± 11.6 mmHg, p = 0.004)/(127 ± 13 vs 112.5 ± 10.4 mmHg, p = 0.005), peripheral/central diastolic blood pressure (89.9 ± 8.9 vs 82.2 ± 8, p = 0.022)/(91 ± 9.3 vs 82.2 ± 8.3, p = 0.014), total cholesterol (252 ± 43.5 vs 198 ± 39.8 mg/dL, p < 0.001), LDL cholesterol (167 ± 24 vs 118 ± 40.8 mg/dL, p < 0.001) and C-reactive protein (7.6 ± 35.4 vs 1 ± 1.2 mg/L p < 0.001) compared with controls. Conclusion: Psoriasis patients show increased PWV, IMT, peripheral and central blood pressures, and serum cholesterol and C-reactive protein levels, denoting a higher cardiovascular risk.

Resumo Fundamento: A psoríase correlaciona-se a distúrbios metabólicos, ateromatose precoce e aumento do risco cardiovascular. Objetivos: Avaliar marcadores de doença cardiovascular na população psoriásica. Métodos: Estudo observacional transversal, envolvendo 11 participantes psoriásicos e 33 controles. Foram avaliados parâmetros antropométricos, laboratoriais, hemodinâmicos e de imagem. A rigidez arterial foi avaliada por oscilometria da artéria braquial. A espessura médio-intimal (EMI) e a função diastólica do ventrículo esquerdo foram avaliadas por meio da ecografia e ecocardiografia Doppler. As comparações de variáveis numéricas entre grupos foram realizadas por teste t-Student e Wilcoxon Mann-Whitney para amostras independentes, adotando-se o nível de significância de 5%. Resultados: Os pacientes psoriásicos apresentaram aumento de VOP (9,1 ± 1,8 e 8 ± 2 m/s, p = 0,033), EMI da artéria carótida comum esquerda (p = 0,018) e maior proporção de percentil > 75 pela tabela ELSA (54,5 e 18,2%, p = 0,045) e) quando comparados aos controles. Pacientes psoriásicos também mostraram aumento nos seguintes parâmetros em relação ao grupo controle, respectivamente: pressão arterial sistólica periférica/central (137,1 ± 13,2 e 122,3 ± 11,6 mmHg, p = 0,004)/(127 ± 13 e 112,5 ± 10,4 mmHg, p = 0,005), pressão arterial diastólica periférica/central (89,9 ± 8,9 e 82,2 ± 8 mmHg, p = 0,022) / (91 ± 9,3 e 82,2 ± 8,3 mmHg, p = 0,014), colesterol total (252 ± 43,5 e 198 ± 39,8 mg/dL, p < 0,001), colesterol LDL (167 ± 24 e 118 ± 40,8 mg/dL, p < 0,001) e proteína C reativa (7,6 ± 35,4 e 1 ± 1,2 mg/L, p<0,001). Conclusão: Pacientes psoriásicos apresentam elevações de VOP e EMI, além de maiores pressões arteriais periféricas e centrais, níveis séricos de colesterol e de proteína C reativa, denotando maior risco cardiovascular.

Mecânica respiratória de pacientes com obesidade mórbida / Respiratory mechanics of patients with morbid obesity

RESUMO Objetivo avaliar os diferentes componentes da resistência do sistema respiratório e a força muscular respiratória, bem como investigar a ocorrência de limitação de fluxo expiratório (LFE) de pacientes obesos mórbidos (OM) na posição sentada. Métodos a amostra foi composta de OM (IMC ≥ 40 kg/m2) e de indivíduos não obesos (NO) com IMC entre 18 e 30 kg/m2. O protocolo foi composto de: avaliação antropométrica e da função respiratória (espirometria, pressões inspiratória (PIM) e expiratória máximas (PEM) e oscilometria de impulso). Na comparação entre os grupos, foi utilizado o teste T para amostras não pareadas. As correlações foram avaliadas pelo teste de Pearson, e o nível de significância foi de 5%. Resultados Foram avaliados 50 OM (idade 40,0 ± 10,4 anos, 1,64 ± 0,09 m, 138,8 ± 33,6 kg e 50,7 ± 8,9 kg/m2), além de 30 NO (idade 37,6 ± 11,5 anos, 1,67 ± 0,09 m, 65,2 ± 10,3 kg e 23,2 ± 22 kg/m2). Os OM apresentaram maiores valores de resistência total, central, de vias aéreas, tecidual e periférica quando comparados aos NO. Nenhum paciente apresentou LFE. A circunferência abdominal se associou com variáveis espirométricas PIM e PEM. A relação cintura-quadril se correlacionou com variáveis de mecânica respiratória, além das espirométricas PIM e PEM. Conclusões pacientes com obesidade mórbida e sem padrão espirométrico obstrutivo apresentam aumento nas resistências total, de vias aéreas, periférica e tecidual do sistema respiratório quando comparados a não obesos. Esses indivíduos, entretanto, não apresentam limitação de fluxo expiratório e redução da força muscular respiratória.

ABSTRACT Objective To evaluate the different components of the resistance of the respiratory system, respiratory muscle strength and to investigate the occurrence of expiratory flow limitation (EFL) in patients with morbid obesity (MO) when seated. Methods The sample was composed of MO (BMI≥40 kg/m2) and non-obese individuals (NO) with a BMI between 18 and 30 kg/m2. The protocol consisted of the anthropometric assessment and the following measures of respiratory function: spirometry, maximal inspiratory and expiratory pressures (MIP and MEP, respectively) and impulse oscillometry. The group comparison was performed using T-test for unpaired samples. The correlations were evaluated by the Pearson test with a significance level of 5%. Results Fifty MO (age 40±10.4 years, 1.64±0.09 m, 138.8±33.6 kg and 50.7±8.9 kg/m2), and 30 NO (age 37.6±11.5 years, 1.67±0.09 m, 65.2±10.3 kg and 23.2±22 kg/m2) were evaluated. The MO showed higher values of total, peripheral, airways, tissue and central resistance when compared to the NO. No patient showed EFL. The waist circumference was associated with spirometric variables, MIP, and MEP. The waist-to-hip ratio was correlated to respiratory mechanics and spirometric variables, MIP, and MEP. Conclusion Morbidly obese patients with no obstructive spirometric pattern show increased total, airway, peripheral, and tissue respiratory system resistance when compared to nonobese. These individuals, however, do not present with expiratory flow limitation and reduced respiratory muscles strength.

Value of impulse oscillometry technique in assessment of silicosis / 中国职业医学

OBJECTIVE: To investigate the value of impulse oscillometry(IOS) technique in the assessment of silicosis. METHODS: A judgment sampling method was used to select 90 patients with silicosis as the silicosis group, which includes 30 cases in each stage of silicosis(stage 1-3). Thirty workers with no exposure history to free silica dust were selected as the control group. All subjects underwent routine pulmonary function and IOS test. RESULTS: The total respiratory impedanceat at 5 Hz(Z5), reactance at 5 Hz(X5), airway resistance at 5 Hz(R5), airway resistance at 20 Hz(R20), difference of R5 and R20(R5-R20), low frequency reactance area(AX) and resonance frequency(Fres) were higher in silicosis group than those in control group(P<0.05). The above IOS indicators showed an upward trend with the higher stages of silicosis(P<0.05). X5 was positively correlated with forced vital capacity(FVC), one-second expiratory capacity(FEV_1), FEV_1/FVC(P<0.05). Z5, R5, R50-R20 and Fres were negatively correlated with FVC, FEV_1 and FEV_1/FVC(P<0.05). CONCLUSION: IOS detection is highly sensitive for early diagnosis of silicosis. The parameters of airway resistance in IOS is correlated with the parameters of ventilatory dysfunction in routine pulmonary function test, which is of great value for the evaluation of silicosis.