OBJECTIVEImpulse oscillometry (IOS) is a new method for determination of breathing mechanics, which features convenient operation, good repeatability and wider range analysis. As there is no standardized normal value in China at present, this study will provide a normal value of lung function determination by impulse oscillometry for children in Chengdu area.

METHODTotally 549 children were chosen at random from Chengdu area, with 292 boys and 257 girls who were 4 to 14 years old. The subjects were assigned into 10 age groups according to their chronological age with one year difference between every two adjacent groups. The respiratory total impedance (Zrs), viscosity resistance (Rrs) and elastic resistance (Xrs) at various oscillation frequency were measured by the Master Screen IOS which was manufactured by German Jaeger Company. The measured data were treated with the linear stepwise multiple regression, and established the prediction equation. At the same time, paired comparison was carried out with the measured data and equation obtained from this study, Lechtenboerger equation and prediction equation obtained from Guangzhou area.

RESULTThe total impedance and airway resistance were negatively correlated with the children's height and age. Zrs (male) = -0.756 + 189.586/height, r = -0.782, P < 0.001; Zrs (female) = -0.497 + 152.468/height, r = -0.726, P < 0.001. Rrs became the same in trend; while Xrs were proportional to the height, e.g. the values increased as the height increased. The difference of the airway resistance (R(5)-R(20)) was negatively correlated with the children's height: R(5)-R(20) (male) = 0.601 - 0.0034 x height, r = -0.677, P < 0.001; R(5)-R(20) (female) = 0.549 - 0.0031 x height, r = -0.658, P < 0.001. Among the relationships with many impulse oscillometry parameters, height ranked at first place; age at second. The multiple regression equation of IOS primary index was established. Both the measured data and the correlation coefficient of the study obtained equation were greater than the coefficient correlation of the Lechtenboerger equation, but had no significant difference compared with that of prediction equation in Guangzhou area.

CONCLUSIONThe normal value in impulse oscillometry in children in Chengdu area is different from the predicted parameters in other countries. The equation obtained from this study seems to be more suitable for the children in its local area. It is recommended to apply the predicted value from the corresponding population in the determination of the lung function by impulse oscillometry.

Airway Resistance ; physiology ; Child ; China ; Electric Impedance ; Female ; Humans ; Male ; Oscillometry ; methods ; Respiratory Function Tests ; methods ; Respiratory Physiological Phenomena

OBJECTIVETo characterize dark-adapted and light-adapted oscillatory potentials (OPs) in human electroretinogram (EGR) elicited by flashing light stimulation of the same intensity.

METHODSDark- and light-adapted ERGs of normal eyes were studied. The frequency spectra of the extracted dark-adapted OPs and light-adapted OPs were analyzed by a fast Fourier transform. The peak frequency, latency and total power of the OPs were determined.

RESULTSThe averaged peak frequency, latency, and power of the dark-adapted OPs was 125.3∓9.93 Hz, 41.7∓3.56 ms, and 9.25∓5.55 (V·s)(2), as compared with 79.5∓6.79 Hz, 50.8∓5.36 ms, and 3.56∓2.18 (V·s)(2) for light-adapted Ops, respectively, showing significant differences in the parameters between dark- and light-adapted Ops (P<0.001).

CONCLUSIONSCompared with dark-adapted OPs, light-adapted Ops is characterized by a lower peak frequency and a lower power with a prolonged latency.

Adaptation, Ocular ; physiology ; Adult ; Dark Adaptation ; physiology ; Electroretinography ; methods ; Female ; Humans ; Male ; Oscillometry ; Retina ; physiology ; Young Adult

OBJECTIVEImpulse oscillometry (IOS) is a novel technique for the evaluation of pulmonary function. Soluble intercellular adhesion molecule-1 (sICAM-1) and soluble vascular cell adhesion molecule-1 (sVCAM-1) are definitive indicators for the severity of asthma. This study aimed to explore the relationship of IOS pulmonary function with sICAM-1 and sVCAM-1, and their values in childhood asthma.

METHODSIOS via Master Screen System for pulmonary function was performed in 40 children with acute asthma and 25 healthy children. Twenty-three of 40 children with acute asthma were re-tested for IOS pulmonary function at remission. sICAM-1 and sVCAM-1 levels were measured in 23 children with acute asthma, 20 asthmatic children at remission and 16 healthy children.

RESULTSThe parameters of IOS pulmonary function, R5, R20, R5-R20, X5, Fres and Zrs in children with acute asthma were significantly higher than in asthmatic children at remission and in normal controls (q= 2.91-15.61, P < 0.01 or 0.05). There were significant differences in R5, R5-R20, Fres and Zrs between the asthmatic children at remission and normal controls (q= 3.08- 9.19, P < 0.01 or 0.05). sICAM-1 and sVCAM-1 levels in children with acute asthma were significantly higher than in asthmatic children at remission and in normal controls (q= 6.23-26.15, P < 0.01). The asthmatic children at remission had higher levels of sICAM-1 and sVCAM-1 than the normal controls (q=16.86, 12.46, P < 0.01). R5-R20 positively correlated with sICAM-1 and sVCAM-1 in children with acute asthma (r=0.45, 0.57, P <0.05).

CONCLUSIONSIOS for pulmonary function and sICAM-1 and sVCAM-1 may be used to evaluate the severity and therapeutic effects of childhood asthma. A correlation exists between IOS pulmonary function and sICAM-1 and sVCAM-1.

Asthma ; physiopathology ; Child ; Child, Preschool ; Female ; Humans ; Intercellular Adhesion Molecule-1 ; blood ; Lung ; physiopathology ; Male ; Oscillometry ; methods ; Respiratory Function Tests ; methods ; Vascular Cell Adhesion Molecule-1 ; blood

Asthma ; physiopathology ; Child ; Female ; Humans ; Male ; Maximal Expiratory Flow-Volume Curves ; Oscillometry ; methods ; Pulmonary Disease, Chronic Obstructive ; physiopathology ; Respiratory Function Tests

OBJECTIVETo study the roles of allergen testing in vitro and impulse oscillometry for lung function measurements in preschool children with cough variant asthma (CVA).

METHODSethodsForty-four preschool children with acute asthma, 41 with chronic asthma, 46 with CVA, and 35 healthy preschool children as control were recruited in the study. Inhaled allergen, food allergen, and mite-specific IgE were determined by Pharmacia UniCAP System. Serum eosinophil cationic protein (ECP) and total IgE levels were measured. Lung function was assessed by impulse oscillometry.

RESULTSThe positive rates of inhaled allergen and food allergen, and total IgE levels in the CVA, acute asthma and chronic asthma groups were higher than those in the control group (P<0.01). However, no significant differences were found among the three case groups. The serum ECP levels in the CVA group were lower than those in the acute asthma group (P<0.01), but did not show differences when compared with the chronic asthma group. The impulse oscillometry demonstrated that the respiratory total impedance (Zrs), airway resistance at 5 Hz (R5), airway resistance at 20 Hz (R20), subtracting R5 from R20 (R5-R20) and resonant frequency (Fres) in the CVA, acute asthma and chronic asthma groups were higher than those in the control group (P<0.01). Zrs, R5, R20, R5-R20, and Fres in the CVA and chronic asthma groups were lower than those in the acute asthma group (P<0.01). Serum ECP levels were positively correlated with Zrs, R5, R5-R20 and Fres (P<0.05) in the CVA and chronic asthma groups.

CONCLUSIONSThe measurements of allergens, serum ECP and impulse oscillometry for lung function are helpful for the evaluation of airway inflammation and airway obstruction in preschool children with CVA.

Allergens ; immunology ; Asthma ; immunology ; physiopathology ; Child ; Child, Preschool ; Cough ; immunology ; physiopathology ; Eosinophil Cationic Protein ; blood ; Humans ; Immunoglobulin E ; blood ; Lung ; physiopathology ; Oscillometry ; methods

Aged ; Aged, 80 and over ; Airway Resistance ; Forced Expiratory Volume ; Humans ; Oscillometry ; Prospective Studies ; Pulmonary Disease, Chronic Obstructive ; diagnosis ; physiopathology ; Respiratory Function Tests ; methods ; Sensitivity and Specificity

BACKGROUND: Forced oscillation technique (FOT) is a method to characterize the mechanical properties of the respiratory system over a wide range of frequencies. Its' most important advantage is to require minimal cooperation from the subject. This study was performed to evaluate the usefulness of the FOT applications in patients with bronchial asthma by estimating the associations between asthma severity and FOT parameters, and the relationships between FOT and spirometry parameters. METHODS: 216 patients with asthma were enrolled in this study. Patients were classified into 3 different groups according to their symptoms and pulmonary functions. Respiratory impedance, resistance (at 5 Hz, 20 Hz, 35 Hz) and resonant frequency were measured by FOT. FEV1, FVC and MMEF were measured with conventional spirometry. RESULTS: There were significant differences of resonant frequency, resistance at 5 Hz and 20 Hz, resistance difference at 5 Hz and 20 Hz according to asthma severity (p<0.05, respectively). Resonant frequency, resistance at 5 Hz, and impedance were significantly correlated with FEV1 (r = -0.55, -0.48, -0.49, p<0.05, respectively), and with MMEF in patients with normal pulmonary function (r = -0.37, -0.35, -0.34, p<0.05, respectively). Resistance at 5 Hz had similar reproducibility compared to FEV1 (resistance at 5 Hz, r = 0.78 vs FEV1, r = 0.79). CONCLUSION: FOT is a useful and alternative method to evaluate the clinical status of bronchial asthma. Further studies will be needed to clarify its value for a wide range of clinical applications.
Adult ; Aged ; Analysis of Variance ; Asthma/*diagnosis ; Comparative Study ; Female ; Forced Expiratory Volume ; Human ; Korea ; Male ; Middle Age ; Oscillometry ; Probability ; Sensitivity and Specificity ; Severity of Illness Index ; Spirometry/methods

PURPOSE: High-sensitivity assays enabled the identification of C-reactive protein (hs-CRP) at levels that were previously undetectable. We aimed to determine if hs-CRP could reflect airway inflammation in children, by comparing hs-CRP with spirometry and impulse oscillometry (IOS) parameters and symptomatic severities. MATERIALS AND METHODS: A total of 276 asthmatic children who visited Severance Children's Hospital from 2012-2014 were enrolled. Serum hs-CRP and pulmonary function tests were performed on the same day. Patients were divided into hs-CRP positive and negative groups (cut-off value, 3.0 mg/L). RESULTS: Of the 276 asthmatic children [median age 7.5 (5.9/10.1) years, 171 boys (62%)], 39 were hs-CRP positive and 237 were negative. Regarding spirometry parameters, we observed significant differences in maximum mid-expiratory flow, % predicted (FEF25-75) (p=0.010) between hs-CRP positive and negative groups, and a negative correlation between FEF25-75 and hs-CRP. There were significant differences in the reactance area (AX) (p=0.046), difference between resistance at 5 Hz and 20 Hz (R5-R20) (p=0.027), resistance at 5 Hz, % predicted (R5) (p=0.027), and reactance at 5 Hz, % predicted (X5) (p=0.041) between hs-CRP positive and negative groups. There were significant positive correlations between hs-CRP and R5 (r=0.163, p=0.008), and X5 (r=0.164, p=0.007). Spirometry and IOS parameters had more relevance in patients with higher blood neutrophil levels in comparison to hs-CRP. CONCLUSION: Hs-CRP showed significant correlation with FEF25-75, R5, and X5. It can reflect small airway obstruction in childhood asthma, and it is more prominent in neutrophil dominant inflammation.
Airway Obstruction/*diagnosis/etiology ; Asthma/*diagnosis/physiopathology ; C-Reactive Protein/*analysis ; Child ; Child, Preschool ; Female ; Forced Expiratory Volume ; Humans ; Inflammation/*etiology ; Male ; Neutrophils/metabolism ; Oscillometry/*methods ; Respiratory Function Tests/*methods ; Respiratory System ; Sensitivity and Specificity ; *Spirometry