脉冲振荡法测定支气管哮喘患者呼吸阻抗的临床意义

目的探讨呼吸阻抗对支气管哮喘的诊断价值。方法185例健康人和192例支气管哮喘患者进行脉冲振荡肺功能（IOS）测定，并与常规肺通气功能比较。结果支气管哮喘患者与健康人相比，Zrs、Re、Rp、Fres、R均显著增高，X明显降低。支气管哮喘患者Zrs、Rp、Fres、R5、R5～R20与肺通气功能呈显著负相关，与Fres的相关性最为密切。结论IOS测定可用于支气管哮喘的诊断，Fres为诊断支气管哮喘气流阻塞最敏感的指标。     

Exercise induced changes in spirometry and impulse oscillometry measurements in persistent allergic rhinitis

The Link between allergic rhinitis and asthma is well known. Bronchial hyperreactivity (BHR) may be present in rhinitis. The present study was aimed to compare airway responses in patients with rhinitis symptoms alone following exercise challenge, and to determine relationship of two different respiratory function tests.98 subjects with rhinitis were investigated by spirometry and impulse oscillometry before and after exercise challenge.No significant difference was detected between spirometry and impulse oscillometry measurements before and after exercise challenge in subjects with rhinitis alone. No correlation between spirometry and impulse oscillometry indices was found in pre and post-exercise stages.We therefore conclude that exercise challenge is not an appropriate test to determine airway hyperresponsive in subjects with rhinitis symptoms alone and findings of spirometry and impulse oscillometry are not interrelated.     

Asthma symptoms do not predict spirometry

BACKGROUND:

Asthma is a disease characterized by variable airflow obstruction, but the measurement of airflow is often omitted in the process of diagnosis and management of the disease.

OBJECTIVES:

Features of asthma severity and control were examined to determine the extent to which objective measurements, including forced expiratory volume in 1 s and forced expiratory volume in 1 s/forced vital capacity, correlated with other manifestations of the disease.

METHODS:

Subjects were a consecutive sample of patients with asthma attending a university-based asthma clinic. All subjects underwent routine assessment using a standard questionnaire and spirometry.

RESULTS:

A total of 500 subjects were included in the present study, and their assessment showed that neither symptoms nor history could predict or be predicted by their measurements of lung function.

CONCLUSION:

Routine measurement of lung function should be performed on subjects with asthma if normal or near-normal lung function is a desired component of asthma control.     

脉冲振荡肺功能治疗支气管哮喘的临床分析

目的探讨脉冲振荡(IOS)肺功能治疗儿童支气管哮喘的效果。方法对发作组、缓解组、对照组行IOS和PFT检查。对比IOS和PFT的检查结果并分析其相关性。结果三组的IOS各项指标除R20无显著差异外,其余各项指标均有显著差异。三组PFT各项指标均有显著差异。发作期与缓解期各IOS与PFT检查指标的异常率均不同。Zrs和FVC、R5-R20和FEF25~FEF75、Fres和FEV1呈负相关;X5和FEF50和FEF75呈正相关。结论 IOS和PFT间具较好相关性,IOS是儿童哮喘治疗中的理想监测指标。     

Peripheral bronchial obstruction evaluation in patients with asthma by lung sound analysis and impulse oscillometry

Background

Computer-aided lung sound analysis (LSA) has been reported to be useful for evaluating airway inflammation and obstruction in asthma patients. We investigated the relation between LSA and impulse oscillometry with the evaluation of peripheral airway obstruction.

脉冲振荡法在评价支气管哮喘患者小气道功能中的应用

目的探讨脉冲振荡法（IOS）在支气管哮喘（简称哮喘）患者小气道功能中的应用价值。方法选取40例哮喘患者分别于急性发作期和缓解期应用IOS法和肺通气法检测其肺功能,并与40例健康者相关指标进行比较。结果IOS检测指标R5、Fre5、X5、R5-R20急性发作组明显高于缓解组和健康对照组（P〈0．05）;R5—R20等缓解组亦高于健康对照组（P〈0．05）,而R20两组间差异无统计学意义（P〉0．05）;FVC、FEV1／FVC、FEV1、FVC％pred、PEF、PEF％pred、FEF5。％在急性发作期低于缓慢期和健康组,而缓解组和健康组间差异无统计学意义。结论哮喘缓解期患者通气功能恢复正常,但其小气道功能仍然存在异常;IOS法是哮喘病情监测有效的工具,较常规肺通气法其对小气道功能的检测尤为敏感。     

Montelukast improves pulmonary function measured by impulse oscillometry in children with asthma (Mio study)

BACKGROUND: Systemic drugs-like oral montelukast can reach lower airways, whose inflammation plays a crucial role in the evolution of asthma, while inhaled drugs hardly reach them. The impulse oscillometry (IOS) technique is useful to evaluate both central and peripheral airways function. OBJECTIVE: To measure the effect of oral montelukast on airways resistance evaluated by oscillometry in children with asthma. METHODS: In an open study, respiratory function in 23 children with mild asthma and a positive bronchodilator response was assessed by spirometry and oscillometry. They took oral montelukast during 4 weeks and were again evaluated. As a control group, 23 similar patients with no preventive treatment underwent the same study. MEASUREMENTS AND MAIN RESULTS: Children on oral montelukast showed improvements (measured in kPa s L(-1)) in all oscillometry parameters: mean 0.20 (22.4%) in total respiratory impedance Zrs5, 0.18 (21.8%) in total airway resistance Rrs5, 0.09 (17.8%) in central airway resistance Rrs20, and 0.09 (28.8%) in distal capacitive reactance Xrs5; the frequency of resonance Fres improved 2.3 Hz (8.7%) (P<0.05 in all cases). No changes were found in the control group. Expiratory flows showed no changes except for a small (0.23 L s(-1), 7.4%) but significant worsening of FEF25-75 in the control group. CONCLUSIONS: Montelukast improves central and especially peripheral airways function in the first month of treatment, as evaluated by IOS, a technique based on tidal breathing analysis which is more sensitive than conventional forced spirometry.     

脉冲振荡法与舒张试验结合对支气管哮喘与慢性阻塞性肺疾病鉴别诊断的意义

目的探讨脉冲振荡法(IOS)与舒张试验结合对支气管哮喘与慢性阻塞性肺疾病(COPD)鉴别诊断的意义。方法随机对60例急性期哮喘及78例COPD患者在喷药前后分别进行包括IOS、常规肺通气在内的肺功能检测,比较两组喷药前后IOS测得值及其变化程度的差异。结果喷药前支气管哮喘与COPD组IOS值差异无显著性(P＞0．05),但喷药后支气管哮喘组包括Fres、R5-R20、R5．X5在内的IOS值变化幅度均明显大于COPD组(P均＜0．05)。支气管哮喘组与FEV_(?)增加相关性密切的IOS指标依次为Fres＞R5- R20＞R5＞X5。结论支气管哮喘与COPD患者脉冲振荡结果均显示气道阻力增加与肺顺应性降低,但IOS与舒张试验结合有助于两者鉴别诊断。     

Effect of inhaled corticosteroids on small airways in asthma: Investigation using impulse oscillometry

BackgroundSmall airways appear to have an important role in asthma. Hydrofluoroalkane-134a beclomethasone dipropionate (HFA-BDP) has ultrafine particles and accordingly greater deposition in the small airways than chlorofluorocarbon (CFC)-BDP. Impulse oscillometry systems (IOS), a new and non-invasive measure of pulmonary function, can examine the resistance of total (R5), large (R20), and small airways (R5–R20) separately, and low-frequency reactance area (AX), also considered a measure of small airways dysfunction.MethodsMild-to-moderate asthmatics who were inhaled corticosteroid naïve were randomized to receive 200 mcg HFA-BDP bid (n = 26) or 400 mcg CFC-BDP bid (n = 12) for 12 weeks in an open-label manner. Following baseline measurements, IOS and spirometry were repeated every 4 weeks, and methacholine challenge to separately assess airway sensitivity and airway reactivity and lung volumes at 12 weeks.ResultsModerate correlations were found between R5–R20 or AX and spirometry and lung volume indices of small airways, and between R20 and peak expiratory flow at baseline. The two groups did not significantly differ in baseline clinical or functional parameters. At 12 weeks, all IOS indices improved in the HFA-BDP group, whereas all but R5–R20 improved with CFC-BDP. R5–R20 and AX progressively improved with HFA-BDP; these changes achieved statistical significance at 12 weeks versus the CFC-BDP group. Other IOS and spirometry indices failed to show such trends. HFA-BDP significantly attenuated methacholine airway sensitivity; the degree of this attenuation strongly correlated with R5–R20 and AX baseline values, and with improvement of AX with treatment.ConclusionHFA-BDP is an effective treatment of small airways in asthma. Prolonged treatment provides a progressive effect over time, which is associated with an attenuation of airway responsiveness.     

47例正常儿童和21例哮喘儿童气道阻力分析

目的　探讨脉冲振荡法对儿童肺功能气道阻力 (IOS)检测的应用评价。方法　采用脉冲振荡法 ,对正常组 4 7例 ,哮喘发作组 2 1例进行肺功能测定 ,组间比较总黏性气道阻力 (R5) ,中心气道黏性阻力 (R2 0 ) ,外周气道黏性阻力 (R5- R2 0 ) ,外周气道弹性阻力 (X5) ,总阻抗 (Zres)。结果　在总阻抗、总黏性气道阻力呈显著性差异 (P<0 .0 5 ) ,在外周气道黏性及弹性阻力呈极显著性差异 (P<0 .0 1) ;而在中心气道黏性阻力上两组却无显著性差异(P>0 .0 5 )。在正常儿童组外周气道存在黏性阻力分布 :0 .138± 0 .0 99k Pa/ l/ s。结论　脉冲振荡法可以作为儿童肺功能检测和小儿哮喘诊断及治疗监测的方法。     

The airway hyperresponsiveness to methacholine may be predicted by impulse oscillometry and plethysmography in children with well-controlled asthma

Objective: Airway hyperresponsiveness (AHR) is a hallmark of asthma. Methacholine challenge test which is mostly used to confirm AHR is not routinely available. The aim of this study was to investigate the predictive values of fractional exhaled nitric oxide (FeNO), impulse oscillometry (IOS), and plethysmography for the assessment of AHR in children with well-controlled asthma. Methods: 60 children with controlled allergic asthma aged 6–18 years participated in the study. FeNO measurement, spirometry, IOS, and plethysmography were performed. Methacholine challenge test was done to assess AHR. PC20 and dose response slope (DRS) of methacholine was calculated. Results: Mild to severe AHR with PC20 < 4 mg/ml was confirmed in 31 (51.7%) patients. Baseline FeNO and total specific airway resistance (SRtot)%pred and residual volume (RV)%pred levels in plethysmography were significantly higher and FEV1%pred, FEV1/FVC%pred, MMEF%pred values were lower in the group with PC20 < 4 mg/ml. FeNO, SRtot%pred, and RV%pred levels were found to be positively correlated with DRS methacholine. The higher baseline FeNO, frequency dependence of resistance (R5–R20) in IOS and SRtot%pred in plethysmography were found to be significantly related to DRS methacholine in linear regression analysis (β: 1.35, p = 0.046, β: 4.58, p = 0.002, and β: 0.78, p = 0.035, respectively). The cut-off points for FeNO and SRtot% for differentiating asthmatic children with PC20 < 4 mg/ml from those with PC20 ≥ 4 mg/ml were 28 ppb (sensitivity: 67.7%, specificity: 72.4%, p < 0.001) and 294.9% (sensitivity: 35.5%, specificity: 96.6%, p = 0.013), respectively. Conclusion: IOS and plethysmography may serve as reliable and practical tools for prediction of mild to severe methacholine induced AHR in otherwise “seemingly well-controlled’’ asthma.     

Migration to a western country increases asthma symptoms but not eosinophilic airway inflammation

The prevalence of asthma symptoms varies markedly throughout the world. However, the asthma mechanisms involved are not defined. Studying the effects of migration can help identify the reasons for this geographic variation. The aims of this study were to examine the prevalence of asthma symptoms, airway hyperresponsiveness (AHR), and induced sputum eosinophils in adolescents who migrate to Australia. The study was conducted in Sydney, Australia, where adolescent students completed a video symptom questionnaire, hypertonic saline challenge, sputum induction, and allergy skin testing. The 211 students had widely different cultural backgrounds, including Asian, South Pacific, Middle Eastern, European, and African countries. Among adolescents who were migrants to Australia, the prevalence of asthma symptoms was higher than that reported using a similar methodology in their country of origin. Asthma symptom prevalence was related to residence time in Australia. The prevalence of wheeze was 17.2% in recent arrivals, 20.5% in adolescents living in Australia for >2 years, and 36.3% in those living all their lifetime in Australia (P = 0.013). For every year of residence in Australia, there was an 11% increase in prevalence of current wheeze (odds ratio, 1.11; P = 0.02). This effect was not related to atopy, AHR, or eosinophilic airway inflammation. Sputum neutrophils were elevated in recent arrivals. In conclusion, adolescents who migrate to Australia report increased asthma symptoms, compared to their country of origin, and asthma symptoms are further increased for every additional year of residence in Australia. The development of wheeze after migration to Australia was independent of eosinophilic inflammation and consistent with noneosinophilic asthma mechanisms.     

脉冲振荡技术在COPD与支气管哮喘鉴别诊断中的价值

目的探讨脉冲振荡法(IOS)对COPD、支气管哮喘(哮喘)的鉴别诊断价值。方法 102例受试者(其中AECOPD40例,哮喘急性发作期36例,以及健康者26例)完成脉冲振荡法检查、肺通气功能(PFT)。比较三组间肺通气功能参数、脉冲振荡的全呼吸相阻抗以及吸气-呼气相阻抗的差别。结果 (1)肺通气功能结果:COPD组、哮喘组均表现为阻塞性通气功能障碍,FEV1%pred、FEV1/FVC、PEF%pred差异无统计学意义。(2)哮喘组代表中心气道阻力的指标R20高于COPD组(P<0.01)。(3)COPD组、哮喘组、健康组吸气-呼气相阻抗比较:仅COPD组的呼气相R5-20大于吸气相R5-20、呼气相X5小于吸气相X5(P值分别为0.041、0.017)。另外COPD组的吸气-呼气相的R5-20变化值(ΔR5-20)、X5变化值(ΔX5)大于哮喘组(均P<0.01)。结论脉冲振荡法有助于支气管哮喘与AECOPD的鉴别诊断。     

Comparative analysis of the bronchodilator response measured by impulse oscillometry (IOS), spirometry and body plethysmography in asthmatic children.

BACKGROUND: Asthma is common among young children. The assessment of respiratory resistance by the impulse oscillometry system (IOS), based on the superimposition of respiratory flow by short-time impulses, requires no patient active collaboration. AIM: We evaluated the baseline repeatability and bronchodilator response of IOS indices in preschool children, their correlation with spirometry and whole body plethysmography, and differences between atopic and nonatopic children. PATIENTS AND METHODS: Thirty-three asthmatic children (3-6 yrs.) underwent IOS measurement (R5rs, R20rs and X5rs) by triplicate at the baseline, after placebo and after salbutamol inhalation. Spirometry (FEV1) and whole body plethysmography (sRaw) were made at the baseline and after salbutamol. Baseline within-test (coefficient of variation: CV%) and between-test repeatability (baseline-placebo) were addressed. Bronchodilator response was evaluated by the SD index (change in multiples of the between-test repeatability). RESULTS: Baseline repeatability for R5rs was 4.1%. Its values decreased by 2SD after salbutamol inhalation, and correlated with FEV1 and sRaw at both, baseline (r=-0.51 and r=0.49) and post-salbutamol (r=-0.63 and r=0.54). A trend towards correlation between salbutamol-induced changes in R5rs and in sRaw (r=0.33) was observed. Atopic and non-atopic children showed no differences in lung function. CONCLUSION: IOS was well accepted by young asthmatic children and provided reproducible and sensitive indices of lung function. Resistance values obtained by IOS at low frequency (R5rs) were reproducible and correlated with spirometry and plethysmographic values.