Satomi Hagiwara

Reference Values for Japanese Children's Respiratory Resistance Using the LMS Method

BACKGROUND The forced oscillation technique (FOT) is useful for studying pulmonary function in children, as well as in school children with asthma. However, the standard values for respiratory resistance (Rrs) in Asian school children remain unknown. We evaluated the standard Rrs using a type of FOT, impulse oscillometry (IOS), in healthy Japanese children at elementary and junior high schools. METHODS A total of 795 children (age range: 6-15 years; mean age ± SD: 11.1 ± 2.4 years; 404 boys, 391 girls) at elementary and junior high schools participated in the study. Of the 795 children, we evaluated the Rrs of 537 children aged 6-15 years (mean ± SD: 10.8 ± 2.4 years) using IOS. RESULTS Regression analyses with three IOS parameters, Rrs at 5Hz (R5), Rrs at 20Hz (R20), and Rrs difference between 5Hz and 20Hz (R5-R20), for age, height, weight, and degree of obesity as independent variables demonstrated the strongest correlation between each parameter and childrens height. All parameters decreased with increasing height. Using the lambda-mu-sigma (LMS) method, we created standard curves for the Rrs values based on height. CONCLUSIONS Our standard curves could be useful for diagnosis and control evaluation of childhood asthma.

Changes in the highest frequency of breath sounds without wheezing during methacholine inhalation challenge in children.

A breath sound analyser was used to detect bronchoconstriction without wheezing during methacholine inhalation challenge in children. The highest frequency of inspiratory breath sounds increased significantly during bronchoconstriction and decreased after inhalation of a bronchodilator. The highest frequency of inspiratory breaths sounds was correlated with bronchial reactivity.

Effect of bronchoconstriction on exhaled nitric oxide levels in healthy and asthmatic children

BACKGROUND Exhaled nitric oxide (eNO) has recently been proposed to be a noninvasive marker of airway inflammation in asthma. OBJECTIVE To evaluate the effect of bronchoconstriction by means of methacholine inhalation challenge on levels of eNO in children. METHODS Spirometry, impulse oscillometry, and eNO measurements were performed before and after methacholine inhalation challenge (bronchoconstriction phase) and after beta2-agonist inhalation (bronchodilation phase) in 92 children (62 children with asthma, 13 wheezy children, and 17 healthy children). RESULTS A significant decrease occurred in the eNO level after methacholine inhalation challenge (P < .01). This decrease did not correlate with the percentage decrease in forced expiratory volume in 1 second or with the change in large airway resistance (R20), but it did correlate with the percentage decline in maximal expiratory flow at 50% vital capacity and with the change in small airway resistance (R5-R20). The eNO decrease lasted for 15 minutes after beta2-agonist inhalation in the group with a high percentage decrease in R5-R20 (>200%). On the other hand, in the group with a low percentage decrease in R5-R20 (< or =200%), eNO recovered to the previous level immediately after beta2-agonist inhalation. CONCLUSIONS The eNO level significantly decreases after methacholine inhalation challenge. This decrease primarily depends on bronchoconstriction of the small airways.

A flow- and pressure-controlled offline method of exhaled nitric oxide measurement in children

BACKGROUND Exhaled nitric oxide (eNO) is a noninvasive marker of airway inflammation. However, previous studies show that the offline value is lower than the online value. OBJECTIVE To compare a standard offline eNO measurement apparatus with a modified apparatus that can monitor flow volume and respiratory pressure. METHODS We studied 73 cooperative individuals aged 5 to 28 years (32 children: mean age, 8.3 years; 41 adults: mean age, 21.5 years). We modified the standard device by including a flow meter with a manometer and attaching a plastic tube connected to a 3-way valve to control the resistance. The online and offline (measured using the modified device and the standard device) eNO determinations were compared in a single session and were analyzed using a nitric oxide analyzer. RESULTS There was a good relationship between the online and modified offline eNO measurements in children. The modified offline method showed a stronger correlation with the online method (r = .97 vs. r = .92), and the modified offline eNO value was more similar to the online eNO value than to the standard offline value. The mean difference between the online and standard offline eNO values was 52%, whereas the mean difference between the online and modified offline eNO values was only 10%. CONCLUSIONS Using the offline method, we can easily control the resistance and flow volume to reach the same value measured by the online method in childhood respiratory diseases.

Relationship between bronchial hyperreactivity and asthma remission during adolescence

BACKGROUND Many children with asthma outgrow this disease after the onset of puberty. However, the precise mechanism of outgrowing asthma in children is still unclear. OBJECTIVE To evaluate the characteristics of respiratory physiology during adolescence. METHODS The results of the lung function test and methacholine inhalation challenge were prospectively evaluated in adolescent patients with asthma with and without symptoms. One hundred sixty children with asthma participated. Twenty-eight children had symptom-free adolescent asthma (i.e., remission asthma) (boy to girl ratio, 16:12; mean age, 14.6 years), 25 had intermittent adolescent asthma (boy to girl ratio, 16:9; mean age, 14.9 years), and 47 had symptomatic adolescent asthma (boy to girl ratio, 27:20; mean age, 12.7 years). For comparison purposes, 60 younger children with symptomatic asthma participated. The parameters of bronchial hyperresponsiveness, baseline respiratory resistance, threshold of methacholine (Dmin) (bronchial sensitivity), and speed of bronchial constriction (Sm) (bronchial reactivity) were measured by methacholine inhalation challenge using the continuous oscillation method. RESULTS There was no significant difference in lung function results, such as forced vital capacity and forced expiratory volume in 1 second, between the intermittent asthma and the remission asthma groups. Also, there was no significant difference in baseline respiratory resistance and Dmin between the 2 groups. However, the value of Sm of the remission asthma group was significantly lower than that of the intermittent asthma group (P = .02) and the symptomatic asthma group (P = .02). CONCLUSIONS These data show that the adolescents with asthma remission showed a significant decrease of Sm, whereas Dmin was not changed. These results suggest one of the mechanisms by which asthma is outgrown in children and explain the common clinical aspects of adolescent asthma, such as symptom-free but bronchial hyperresponsive asthma.

Relationship between Exhaled Nitric Oxide and Small Airway Lung Function in Normal and Asthmatic Children

BACKGROUND In children, exhaled nitric oxide (eNO) is usually confounded by factors such as age and height. We evaluated the relationship between eNO and lung function by minimizing the effects of aging and height. METHODS In Study 1, the subjects comprised 738 elementary school children and junior high school children (aged 6 to 15 years, 366 males and 372 females). They were divided into two groups according to age (6-10 years and 11-15 years). A height range was determined by a histogram of height in each group. In Study 2, lung function, respiratory resistance and eNO level were measured in age- and height-limited groups. RESULTS In Study 1, total of 148 younger children ranging in height from 120 to 130 cm and 180 older children ranging in height from 148 to 158 cm participated in Study 2. The level of eNO among asthmatic children was higher than that of normal children in both the younger and the older groups. The decrease in forced expiratory volume in 1 second (FEV(1)) and other parameters of central airway resistance did not correlate with the eNO level. However, the small airway parameters of MMEF and V(25)/HT in older asthmatic children, and V(25)/HT and R(5)-R(20) in younger asthmatic children inversely correlated with eNO. CONCLUSIONS Our data suggest that eNO level inversely correlates with small airway narrowing, and airway inflammation has a significant effect on small airway lung function in asthmatic school children.

Relationship between bronchial hyperresponsiveness and lung function in children age 5 and 6 with and without asthma

It is unknown whether wheezy children have bronchial hyperresponsiveness (BHR) or which lung function parameters are correlated with BHR in children. We evaluated the relationship between BHR parameters and the lung functions by minimizing the effects of age and height in asthmatic, non‐asthmatic wheezers and healthy children.

Consistently high levels of exhaled nitric oxide in children with asthma

Background:  Exhaled nitric oxide (eNO) levels in children are unstable because they are regulated by many potent factors. The purpose of the current study was to evaluate the reliability of eNO levels between a long interval and other lung functions in normal and asthmatic children.

Evaluation of out-in skin transparency using a colorimeter and food dye in patients with atopic dermatitis

Background  Atopic dermatitis is a disease of skin barrier dysfunction and outside stimuli can cross the skin barrier.

Improvement of Out-in skin Transparency and Symptoms by Shower Therapy in Children with Atopic Dermatitis

Background: Atopic dermatitis (AD) in elementary school children often shows resistance against ordinary treatment. The effect of skin care using water-shower therapy was evaluated mainly by physiological methods in the early summer season when aggravation of dermatitis by perspiration increases. Methods: Skin care with shower therapy was administered to sixteen children in six schools and performed during school lunch breaks for six weeks. The eczema area and severity index (EASI) and physiological methods, such as measurement of stratum corneum hydration and the skin transparency index (STI) with a colorimeter, which demonstrates skin barrier dysfunction were observed before and after the trial. No other on-going therapies were changed during this study period. Results: The EASI scores were decreased after showering. Moreover, the stratum corneum hydration and the STI were improved by shower therapy. Significant physiological and clinical improvements in AD were observed. The conclusion of parents after shower therapy was excellent. Conclusions: Skin care with daily shower therapy in elementary school was effective for an improvement of the skin barrier and skin lesions of AD in children. Results of this study support the recommendation of skin care in the treatment of children with AD.