High-resolution computed tomography in young patients with cystic fibrosis: distribution of abnormalities and correlation with pulmonary function tests

Objective

To assess pulmonary abnormalities detected by high-resolution computed tomography (HRCT) in young children with cystic fibrosis (CF) and mild to moderate lung disease.

Study design

High-resolution computed tomography was performed in 60 children, 6 to 10 years old, with mild to moderate lung disease (forced expiratory volume in 1 minute [FEV₁], 52-137; mean, 102; SD, 15% predicted). HRCTs were scored by using a system that evaluates each lobe for severity and extent of CF lung disease. Findings of CF lung disease were tabulated in all subjects and in a subgroup with normal pulmonary function tests. HRCT scores were correlated with FEV₁, forced vital capacity (FVC), and forced expiratory flow between 25% and 75% of expired vital capacity (FEF_25-75) in 57 patients.

Results

Bronchiectasis was present in 35% of subjects, mucous plugging in 15%, and air trapping in 63%. No abnormality was detected in 25%. In 37 subjects with FEV₁, FVC, and FEF_25-75 >85% predicted, bronchiectasis was present in 30%. In 17% of these subjects, bronchiectasis was seen in ≥4 lobes. Correlations between HRCT scores and FEV₁ were significant and showed fair to moderate correlation (r = 0.36-0.46).

Conclusions

High-resolution computed tomography demonstrated a broad range of pulmonary abnormalities in young patients with CF with mild to moderate lung disease. In this study, abnormalities, including bronchiectasis, were common in young children with CF and normal pulmonary function tests.     

Abnormal spirometry in children with persistent allergic rhinitis due to mite sensitization: the benefit of nasal corticosteroids.

Inflammatory processes affecting nasal and bronchial mucosa are similar in nature. The purpose of this study was to examine whether children with perennial allergic rhinitis, without underlying asthma, have impaired pulmonary function. We also investigated whether nasal corticosteroids and loratidine would improve the pulmonary function tests of those children with impaired lung function. Fifty subjects with moderate/severe persistent allergic rhinitis due to exclusively dust mite sensitization and no past medical history suggestive of asthma were assessed. The control group consisted of 26 matched healthy subjects. Subjects with airway obstruction, as detected by forced expiratory volume/1 s (FEV1) or forced expiratory flow from 25/% to 75% (FEF(25-75)) values <80% of those predicted, were treated with loratidine, once a day for 10 days, and daily nasal budesonide for 3 months. We found that 11 of 50 patients (22%) with perennial allergic rhinitis had impaired pulmonary function (FEF(25-75) values <80%), compared to 1/26 (3.8%) of the control group (p < or = 0.05). Reversibility was observed in 9/11 (81.8%), mean 24.7% +/- 10.3%. Within 3 months of treatment, 7/10 had FEF(25-75) > 80% of their predicted values as well as significant improvements in their FEV1 (p = 0.04), and FEV1/FVC (p = 0.04). We conclude that a substantial proportion of children with perennial allergic rhinitis have diminished FEF (25-75) values and reversible airway obstruction. Nasal corticosteroids improve the pulmonary function tests of these children with impaired lung function.     

Effects of passive smoking on lung function in children

BACKGROUND: Passive smoking can have significant effects on lung function with reductions in forced vital capacity (FVC), forced expiratory volume in one second (FEV1) and forced mid-expiratory flow rate (FEF25-75%) of between 5 and 10%. METHODS: Fifty non-smoking children aged 6-15 years, who had no history of asthma or atopy and no parental history of atopy, were assessed with respect to their lung functions (FEV1, FEV1/FVC, FEF25-75%). RESULTS: Thirty-three of these children were being exposed to environmental tobacco smoke inside their homes, while 17 children were not exposed. In the 'passive smoker' group the FEV1, FEV1/FVC and FEF25-75% values were found to be significantly lower than the non-smoker control group's values (P = 0.0080, 0.0228 and 0.0003, respectively). The decrease in FEF25-75% was significantly correlated inversely with the number of cigarettes smoked per day (P = 0.0261). CONCLUSION: There is sufficient evidence to support the notion that environmental tobacco smoke is a serious health burden for children. Considering that recent studies suggest that up to 70% of children grow up in homes with at least one smoker, every effort should be made to reduce these children's exposure to environmental tobacco smoke and to give them a chance to grow up in a more healthy environment.     

Risk factors for reduced lung function in Australian Aboriginal children

AIM: To determine the influence of perinatal and childhood exposures on lung function in a cohort of Australian Aboriginal children. METHODS: This was a cross-sectional study of 547 Northern Territory Aboriginal children, aged 8-14 years, belonging to a birth cohort. Assessment included physical examination and spirometry as well as retrospective review of centralised hospital records. The effect of select perinatal and childhood exposures on lung function outcomes (forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and forced expiratory flow between 25 and 75 s (FEF25-75)) adjusted for age, sex, height and other measures of size was examined using multiple regression. RESULTS: Non-urban residence (FEV1 -5% (95% confidence interval, CI 0.91-0.99), FVC -9% (95% CI 0.87-0.95)), current cough (FEV1 -6% (95% CI 0.91-0.97), FVC -4% (95% CI 0.93-0.97), FEF25-75 -8% (95% CI 0.86-0.98)) and hospitalisations for respiratory disease (FEV1 -10% (95% CI 0.86-0.95), FEF25-75 -12% (95% CI 0.70-0.87)) all had significant negative effects on adjusted lung function measures. Children with a non-Aboriginal ancestor had significantly better lung function. No perinatal exposure other than neonatal lung disease had any significant effect on adjusted lung function. CONCLUSIONS: For Northern Territory Aboriginal children factors related to the childhood environment are more important than perinatal factors in determining childhood lung function.     

Does bronchodilator responsiveness in infants with bronchiolitis depend on age?

OBJECTIVE: To assess the relation between age and bronchodilator responsiveness in infants with bronchiolitis. STUDY DESIGN: In 41 infants (age, 2 to 18 months) with bronchiolitis, lung function was measured with the raised volume rapid thoracoabdominal compression technique before and after salbutamol inhalation. Lung function was quantified in terms of timed volumes (FEV(0.5), FEV(0.75), and FEV(1.0)). A significant change was defined as a postbronchodilator value that differed from baseline by more than twice the within-subject coefficient of variation. RESULTS: For the group, postbronchodilator values did not differ significantly from baseline (DeltaFEV(0.5), 3.8% +/- 9.3%; DeltaFEV(0.75), 3.5% +/- 9.5%; and DeltaFEV(1.0), 4.0 +/- 9.8%). Eleven subjects showed significantly increased timed volumes; 3 presented with a decreased lung function; the remaining patients failed to show a significant change. The mean age of subjects with improved lung function did not differ significantly from the mean age of those with no or paradoxical responses (9.7 +/- 4.7 vs 8.1 +/- 4.1 months); there was no correlation of age with the size of the bronchodilator response. CONCLUSIONS: The results of the current study indicate that bronchodilator responsiveness in infants with bronchiolitis is not age-dependent.     

Influence of genetic variants on childhood lung function – The Generation R Study

Genetic variants associated with adult lung function could already exert the effects on childhood lung function. We aimed to examine the associations of adult lung function‐related genetic variants with childhood lung function and asthma, and whether these associations were modified by atopic predisposition, tobacco smoke exposure, or early growth characteristics. In a population‐based prospective cohort study among 3347 children, we selected 7 and 20 single nucleotide polymorphisms (SNPs) associated with adult forced expiratory volume in 1 second (FEV ₁) and FEV ₁/forced vital capacity (FEV ₁/FVC ), respectively. Weighted genetic risk scores (GRS s) for FEV ₁ and FEV ₁/FVC were constructed. At age 10, FEV ₁, FVC , FEV ₁/FVC , forced expiratory flow between 25% and 75% (FEF _25‐75), and forced expiratory flow at 75% (FEF ₇₅) of FVC were measured, and information on asthma was obtained by parental‐reported questionnaires. The FEV ₁‐GRS was associated with lower childhood FEV ₁, FEV ₁/FVC , and FEF ₇₅ (Z ‐score (95% CI ): ?0.03 (?0.05, ?0.01), ?0.03 (?0.05, ?0.01), and ?0.04 (?0.05, ?0.01), respectively, per additional risk allele). The FEV ₁/FVC ‐GRS was associated with lower childhood FEV ₁/FVC and FEF ₇₅ (Z ‐score (95% CI ): ?0.04 (?0.05, ?0.03) and ?0.03 (?0.05, ?0.02), respectively, per additional risk allele). Effect estimates of FEV ₁‐GRS with FEF _25‐75, FEV ₁, FEF ₇₅, and FVC , and of FEV ₁/FVC ‐GRS with FEV ₁/FVC and FEF _25‐75 were stronger among children exposed to non‐atopic mothers, smoking during pregnancy or in childhood, or those born with a lower birthweight, respectively (P ‐values for interaction < .05). Genetic risk scores were not associated with asthma. Adult lung function‐related genetic variants were associated with childhood lung function. Maternal atopy, smoking during pregnancy or in childhood, and birthweight modified the observed effects.     

昆明市5~14岁儿童肺通气功能参数实测值与Zap

目的 研究昆明市5~14岁健康儿童肺通气功能主要参数实测值占Zapletal方程式预计值的百分比,为临床准确判断肺通气功能提供依据。方法 纳入昆明市5~14岁健康儿童702名,其中男352名,女350名。采用Jaeger肺功能仪测定用力肺活量（FVC）、第1秒用力呼气容积（FEV1）、1秒率（FEV1/FVC）、最大中期呼气流量（MMEF）、用力呼气25%肺活量时瞬时流量（FEF25）、用力呼气50%肺活量时瞬时流量（FEF50）、用力呼气75%肺活量时瞬时流量（FEF75）、最高呼气流量（PEF）、每分钟最大通气量（MVV）,共9项指标,以肺功能仪中提供的Zalpetal预计值公式得出的数值作为所选择儿童的预计值,计算其实测值占预计值的百分比。结果 在702名儿童中,肺通气功能主要参数PEF、FVC、FEV1、FEV1/FVC、MVV实测值占预计值百分比的均值分别波动于102%~114%、94%~108%、98%~113%、98%~107%、141%~183%。气道流速指标功能参数FEF25、FEF50、FEF75、MMEF实测值占预计值百分比分别波动于98%~116%、85%~102%、71%~98%、83%~100%。各参数PEF、FVC、FEV1、FEV1/FVC、MVV、FEF25、FEF50、FEF75、MMEF实测值占Zapletal方程式预计值百分比的下限分别为88.2%、88.4%、92.0%、94.4%、118.5%、82.9%、70.0%、62.1%、70.1%。结论 昆明地区5~14岁健康儿童肺通气功能参数水平与Zapletal方程式提供的正常值存在一定差异;该地区此年龄段的健康儿童肺通气功能参数PEF、FVC、FEV、FEV1/FVC、MVV、FEF25、FEF50、FEF75、MMEF实测值占预计值百分比的正常参考值下限可考虑分别设为88.2%、88.4%、92.0%、94.4%、118.5%、82.9%、70.0%、62.1%、70.1%。     

Pulmonary function and exercise capacity for ELBW survivors in preadolescence: effect of neonatal chronic lung disease

OBJECTIVE: To assess pulmonary function and exercise capacity of apparently asymptomatic children who were born extremely preterm. STUDY DESIGN: Pulmonary function and treadmill testing were performed on 50 children 9 to 15 years old who had birth weight <801 g (extremely low birth weight [ELBW]) and without apparent neurodevelopmental or pulmonary disabilities, compared with 25 children born at term with normal birth weight (NBW). Medical history and physical activity levels were assessed by parent questionnaire. Group differences were determined by two-sample t test. Secondary analysis was performed to assess significant influence of neonatal chronic lung disease (CLD) on outcome measures. RESULTS: Twenty percent of ELBW subjects but no subjects with NBW had clinically abnormal pulmonary function (>2 SD from norms, P=.026). All significant pulmonary function differences except peak expiratory flow rate percentages were accounted for by ELBW subjects who had CLD. Oxygen consumption measurements were significantly lower for subjects with ELBW (30.3+/-6.9 and 38.5+/-5.2 mL/kg/min, P=.000), independent of CLD status. CONCLUSION: Pulmonary function abnormalities consistent with obstructive lung disease were more frequently detected in ELBW children who had neonatal CLD. Low oxygen consumption measurements suggest a lower level of fitness for ELBW children compared with children with NBW.     

The influence of pulmonary function testing on the management of asthma in children

OBJECTIVE: To assess how often in a single encounter that pulmonary function tests (PFTs) influenced management decisions in children with asthma, beyond what was obtained from history and physical examination alone. STUDY DESIGN: Children with asthma (n = 367, age 4 to 18 years) performed spirometry before clinical evaluation. Physicians and nurse practitioners in the outpatient pulmonary office evaluated the children and made initial treatment recommendations before reviewing the spirometry results. Any changes based on the test results were documented. RESULTS: Spirometry was abnormal in 45% of the visits, related to underlying asthma severity but not to clinical findings. PFT results changed management decisions in 15% of visits. This frequency was not affected by the patient's age, disease severity, symptom control, or exam findings. When spirometry did not change treatment decisions, the provider was more likely to maintain therapy (58%) than to increase (17%) or decrease (24%) therapy. In contrast, when spirometry did change treatment decisions, the provider was more likely to increase therapy (75%) than to maintain (20%) or decrease (5%) therapy. CONCLUSION: Without PFTs, providers often overestimated the degree of asthma control. This incorrect assessment could have resulted in suboptimal therapy.     

Daytime pulse oximeter measurements do not predict incidence of pain and acute chest syndrome episodes in sickle cell anemia

A prospective, infant cohort study of children with sickle cell anemia was evaluated to determine the relationship between daytime pulse oximeter measurements and the incidence of pain and acute chest episodes (ACS). A total of 130 children were evaluated. The Pearson correlation between SpO2 and pain and ACS episode rates were 0.00 (P = .97) and 0.10 (P = .27), respectively. Daytime SpO2 cannot independently predict the subsequent rate of pain and ACS episodes.     

哮喘和咳嗽变异性哮喘儿童肺常规通气功能的比较

目的：比较哮喘与咳嗽变异性哮喘（CVA）患儿肺常规通气功能的变化。方法：选择2010年 5月至2011年5月确诊为哮喘或CVA的患儿140例,分为哮喘急性发作组（发作组,50例）、哮喘缓解组（缓解组,50例）和CVA组（40例）;同期正常健康体检儿童30例作为对照组。测定4组儿童用力肺活量(FVC)、一秒钟用力呼气容积(FEV1)、最大呼气峰流速(PEF)、用力呼气25%流速(FEF25)、用力呼气50%流速(FEF50)、用力呼气75%流速(FEF75)、最大呼气中期流速(MMEF75/25)等7项肺功能指标。结果：发作组患儿各项肺功能指标如大气道指标FVC、FEV1、PEF、FEF25及小气道指标FEF50、FEF75、MMEF75/25的实际值/预计值平均水平均<80%,且以FEF50、FEF75、MMEF75/25等小气道指标下降为著。CVA组患儿小气道指标FEF75、MMEF75/25实际值/预计值的平均水平<80%。发作组各项肺常规通气功能指标均低于对照组;缓解组、CVA组FVC、FEV1、FEF25及 MMEF75/25实际值/预计值的平均水平低于对照组;发作组各项肺功能指标均明显低于缓解组和CVA组;CVA组与缓解组各项肺功能指标差异均无统计学意义。结论：哮喘急性发作期患儿存在大小气道功能障碍,以小气道功能障碍为主;CVA患儿以小气道功能轻微障碍为主,与哮喘缓解期相似。     

深圳地区学龄前儿童用力肺活量测定的可行性及正常预计值公式

目的探讨学龄前儿童用力肺活量测定的可行性,并建立儿童常规用力肺活量的正常参考值。方法对深圳地区3~6岁正常儿童343例(男性184例,女性159例),采用意大利COSMED公司生产的COSMED流量传感仪,参考美国胸科协会可接受曲线标准,测定用力肺活量(FVC)、0.5 s用力呼气容积(FEV0.5)、0.75 s用力呼气容积(FEV0.75)、1 s用力呼气容积(FEV1)、0.5s用力呼气容积占用力肺活量比值(FEV0.5/FVC)、0.75 s用力呼气容积占用力肺活量比值(FEV0.75/FVC)、1 s用力呼气容积占用力肺活量比值(FEV1/FVC)、最大呼气中段流量(FEF25%~75%)、最高呼气流量(PEF)、最高吸气流量(PIF)、呼气时间(FET100%)等11个指标,并对各实测指标作多元逐步线性回归及曲线回归,得出回归方程式。比较本方程与国外Nystad方程对指定身高、体重、年龄的儿童的差异。结果所有儿童测试的总成功率为81.3%,其中3~岁、4~岁、5~岁、6~岁各年龄段测试的成功率分别为69.9%、70.8%、92.3%、91.6%;217例(77.7%)可以完成至少2条可接受的曲线。FVC、FEV0.5、FEV0.75、FEV1、FEF25%~75%、PEF、PIF在各年龄组间差异均有统计学意义(P均<0.01);大多数肺功能指标与身高、体重和年龄均呈密切正相关,男性儿童的大多数肺功能指标与身高的关系最为密切,而女性儿童的大多数肺功能指标则与年龄的关系最为密切。所有儿童的呼气时间为(1.61±0.52)s(x-±s),5百分位数为0.9 s,受试儿童中有18例(6.5%)呼气时间<1 s。建立了各肺功能指标的多元回归方程。结论利用儿童心理特点,通过形象比喻、竞赛游戏的方法进行用力肺活量的测定在中国的学龄前儿童中也是可行的。男性儿童肺功能指标受身高变化影响大于体重和年龄变化;女性儿童肺功能指标受年龄变化影响大于身高和体重变化;首次建立了中国深圳地区学龄前儿童用力肺活量正常值及其回归方程式。     

What are the best pulmonary function test parameters for early detection of post‐lung transplant bronchiolitis obliterans syndrome in children?

Post-lung transplant bronchiolitis obliterans syndrome (BOS) is defined as an unexplained fall in forced expiratory volume in 1 s (FEV1) >or=20% of baseline (B). There have been reports in adults that FEF25-75% (>30% decline from B) is more sensitive than FEV1 for the early diagnosis of BOS. Yet, it is not known if other pulmonary function test (PFT) parameters - forced expiratory flow rates at 25-75% of vital capacity (FEF25-75%) and maximal expiratory flow rate at 80% (Vmax80%), 70% (Vmax70%) and 60% (Vmax60%) - are more sensitive indicators for early diagnosis of BOS than FEV1 in post-lung transplant children. We reviewed serial PFTs of 18 patients (ages 14.1 +/- 3.7 yr, 50% female) who had lung transplantation at our institution from 1993 to 1999, and who met the criteria for BOS diagnosis. There was no significant difference in post-transplant days when decline in FEV1 >or=20% of B, FEF25-75% >30% of B, and Vmax80%, Vmax70% and Vmax60% from normal occurred (635 +/- 431, 551 +/- 422 and 454 +/- 287 days, respectively; p = 0.4). However, a decline in FEV1 was the first abnormality in only 39% of the patients, while a decline in FEF25-75% and Vmax at specific lung volume were the first abnormality in 78% and 56% of the patients, respectively. The earliest signs of BOS would be missed in 61% of patients if FEV1 was the primary parameter used for the diagnosis. In order to improve the sensitivity of the diagnosis of post-lung transplant BOS; we speculate that the diagnosis should be based on decreases in FEF25-75% rather than on FEV1.     

Clincial Applications of Respriratory Muscle Electromyographic Activity: (I) Relations Between Forced Expiratory Volume and Expiratory EMG in Asthma

Forced expiratory volume (FEV) and electromyographic activity (EMG) of expiratory muscles were measured in patients with asthma. EMGs of expiratory muscles were recorded from the 8th intercostal space at the anterior axillary line with surface electrodes. Relations between FEV and EMG were compared during asthma attacks and after inhaling a bronchodilator. This method has two advantages in the evaluation of asthma treatment. First; one can determine whether a subject, during an asthma attack, could exhale maximally before and after inhalation of a bronchodilator, second; pre- and post-treatment expiratory force can be compared. A more reliable indication of the effectiveness of treatment can thus be obtained.     

Inhibition of exercise-induced-asthma (EIA) by nedocromil sodium and sodium cromoglycate in children

Nedocromil sodium (Ned) 4 mg, sodium cromoglycate (SCG) 10 mg, and placebo were compared for their efficacy in preventing exercise-induced asthma. Nineteen asthmatic children aged six to 15 years performed a treadmill exercise test before and 20' after a single dose of drug in a double-blind trial. Both active drugs performed significantly better than placebo; in fact the exercise challenge resulted in a mean maximum fall in FEV1 of 26.1 ± 14.9% after placebo, but only of 14.6 ± 11.5% after SCG (P < 0.05), and 11.0 ± 12.4% after Ned (p < 0.01). Measurements of PEFR gave similar results, while the effect of treatment on FEF 25–75 was significant for Ned alone (p < 0.05). Direct comparison between Ned and SCG at different time points demonstrated significant differences in FEV1 at 1 min (p < 0.05) with a better overall performance of Ned. In individual patients, complete protection was provided in 9 patients with SCG, in 14 patients with Ned and in 2 with placebo. No side effects were observed. This study suggests that at the dosages used there are only slight differences between SCG and Ned activity in the prevention of exercise-induced asthma.     

High torquetenovirus loads are correlated with bronchiectasis and peripheral airflow limitation in children

BACKGROUND: The aim of the study was to evaluate the prevalence of torquetenovirus (TTV) infection in a group of children with recurrent lower respiratory tract infections and radiologic evidence of bronchiectasis. Correlations between TTV loads and severity of bronchiectasis and between TTV loads and lung function were evaluated. METHODS: In 38 subjects, high-resolution computed tomography (HRCT) and plasma tests for TTV detection and quantification were done. In 21/38 subjects, spirometry was also performed. RESULTS: TTV was found in 31/38 (81.6%) patients. The correlation between TTV loads and severity of bronchiectasis was statistically significant (r = 0.548; P = 0.01). TTV loads showed inverse correlation with FEF25-75% (r = -0.541; P = 0.011), and FEF25-75%/FVC (r = -0.512; P = 0.018). Inverse correlation was found also between severity of bronchiectasis and functional lung parameters: FEF25-75% (r = -0.635; P = 0.002), FEV1/FVC (r = -0.541; P = 0.011), and FEF25-75%/FVC (r = -0.645; P = 0.002). CONCLUSIONS: This study demonstrated the high prevalence of TTV infection in children with bronchiectasis. Moreover, we have shown a significant correlation between TTV loads and airflow limitation within the peripheral airways, as well as between severity of bronchiectasis and decrease of lung function.     

Low-density areas on high-resolution computed tomograms in chronic pediatric asthma

OBJECTIVE: In children with chronic persistent asthma, we evaluated whether the presence of increased residual volume (RV) after anti-inflammatory treatment correlates with the detection of low-density areas on high-resolution computed tomography (HRCT), similar to those in emphysema. METHODS: Children with a confirmed diagnosis of asthma (n = 32) were enrolled in a prospective study. All patients had reduction of airflow in the peripheral airways, increased RV, and increased serum eosinophil cationic protein (ECP) values indicating airway inflammation. All the children were treated with salmeterol (50 microg twice daily) and fluticasone (250 microg twice daily) for a 3-month period. RESULTS: At the end of treatment, peripheral eosinophil counts, serum ECP, forced expiratory volume in 1 second (FEV(1)), mean forced expiratory flow during the middle half of forced vital capacity (FEF(25-75)), RV, and total lung capacity values improved in all the patients. HRCT was normal in 22 children (68.8%); in the remaining 10 subjects, low-density areas were found despite normalization of FEV(1), FEF(25-75), and significant reduction in ECP. A significant correlation was found between persistence of RV values >150% predicted and the presence of low-density areas on HRCT (r = 0.84, P <.0001). CONCLUSIONS: Structural changes similar to emphysema are also present in asthmatic children. Our findings suggest that the persistence of increased RV may be used to identify subjects with low-density areas on HRCT.     

深圳地区正常学龄前儿童常用吸入器阻力状态下的最高吸气流量分析

目的 研究正常学龄前儿童在各种常用模拟吸入器阻力状态下的最大吸气能力,并探讨其与年龄、身高、体重及通气功能的相关性.方法 使用In-Check DAIL吸气流量检测仪及峰流量仪,对深圳地区3～6岁正常学龄前儿童370例进行常用吸入器[Surehaler气雾剂(Surehaler)、Autohaler气雾剂(Autohaler)、都保(Turbuhaler)、准纳器(Diskus)]阻力状态下吸气流量峰值(PIF)及呼气流量峰值(PEF)测定,同时采用意大利COSMED流量传感仪,测定其通气功能.测量指标包括:无阻力状态下的PIF(PIF-N)、模拟Surehaler时的PIF(PIF-S)、模拟Autohaler时的PIF(PIF-A)、模拟Turbuhaler时的PIF(PIF-T)、模拟Diskus时的PIF(PIF-D)、PEF、用力肺活量(FVC)、0.5秒用力呼气容积(FEVO.5)、0.75秒用力呼气容积(FEV0.75)、一秒用力呼气容积(FEV1)、最大呼气中段流量(FEF25-75)等.结果 (1)370例中有75例不能成功完成吸气或呼气功能测试,实际研究人数295例.PIF-S、PIF-A、PIF-T、PIF-D在3～岁组、4～岁组、5～岁组、6～7岁组各组之间差异有统计学意义,随着年龄增长、身高增高,各最高吸气流量亦明显增高.(2)各模拟阻力状态下PIF与年龄、身高和体重均有相关性,其中以与年龄、身高的相关性较好.(3)在正确完成测试儿童中,PIF-S、PIF-A、PIF-D达到各自吸人器所需最小流量比例均为100%,PIF-T达到Turbuhaler所需最小流量比例为87.5%,未达标学龄前儿童以3～岁组或身高在100 cm以下儿童为主.各阻力模拟状态下的PIF与通气功能主要指标均有较好的相关性,其中以PEF为最佳.结论 可通过正常学龄前儿童常规进行的肺通气功能测试预测其吸气能力的大小;对不同学龄前儿童选择吸入器时,应充分考虑到其吸气能力的大小.