Spirometry in an unselected group of 6-year-old children: the DARC birth cohort study

This study presents reference equations for spirometric parameters in 6-year-old children and evaluates the ability of spirometry to discriminate healthy children from children with asthma. Baseline spirometry and respiratory symptoms were assessed in 404 children participating in a longitudinal birth cohort study. Children with known asthma, possible asthma and a control group also performed bronchodilator measurements. At least two acceptable flow-volume curves at baseline were obtained by 368/404 children (91%). The two best values for FEV1 and FVC were within 5% of each other in 88% and 83% of children, respectively. Linear regression analyses for 242 children included in the reference population demonstrated height to be the main predictor of all spirometric indices except FEV1/FVC. FEV1, FEV75, and FVC correlated reasonably to anthropometric data in contrast to flow parameters. Gender differences were found for FEV1, FVC, and FEV75, but not for flow parameters. Asthma was diagnosed in 25/404 children. Baseline lung function in healthy children and children with asthma overlapped, although asthmatic children could be discriminated to some extent. Bronchodilator tests showed a difference in Delta FEV1(mean) between healthy children and children with asthma (3.1% vs. 6.1%, P < 0.05). At a cut-off point of Delta FEV1 = 7.8%, bronchodilator tests had a sensitivity of 46% and a specificity of 92% for current asthma. Spirometry including bronchodilator measurements was demonstrated to be feasible in 6-year-old children and reference values were determined. Spirometry aids the diagnosis of asthma in young children, but knowledge on sensitivity and specificity of these measurements is a prerequisite.     

Growth of lung function in children with sickle cell anemia

Lung disease is a common cause of morbidity among children with sickle cell disease (SCD). Although cross-sectional studies of children with SCD describe abnormal pulmonary function, the pattern of lung function growth in these children compared to children in the general population is not known. To provide preliminary evidence that growth of lung function is attenuated in children with SCD, we conducted a retrospective cohort study of children with hemoglobin SS (HbSS) ages 6-19 years who received at least two spirometry assessments for clinical care. The growth of lung function in these cases was compared to age, gender, and race-specific children without SCD or respiratory complaints from the Harvard Six Cities Study (H6CS). Seventy-nine children with HbSS contributed 363 spirometry measurements (mean per child = 4.6, median = 4.0, range = 2-17) and 255 controls contributed 1,543 spirometry measurements (mean per child = 6.1, median = 6.0, range = 2-13). Longitudinal forced expiratory volume in 1 sec (FEV(1)) was lower for boys and girls with HbSS compared to children in the general population, P = 0.031 and P = 0.002, respectively. When compared to the H6CS cohort, girls with HbSS showed lower longitudinal forced vital capacity (FVC) (P < 0.001) and FEV(1)/FVC (0.038); there was no difference in FVC or FEV(1)/FVC between boys in the HbSS and H6CS cohort. We conclude that growth of lung function is reduced in children with HbSS compared to children in the general population. Gender may influence the risk of developing abnormal lung function and airway obstruction in children with HbSS.     

Longitudinal pulmonary status of cystic fibrosis children with meconium ileus

Although meconium ileus (MI) is the earliest manifestation of cystic fibrosis (CF), and is associated with poorer growth, the longitudinal pulmonary progression of CF children with MI is not clear. To test the hypothesis that MI is associated with worse pulmonary outcomes, we prospectively compared from diagnosis to 12 years of age 32 CF children with MI to 50 CF children without MI who were diagnosed during early infancy through neonatal screening. Pulmonary outcome measures included respiratory symptoms, respiratory infections, pathogens, antibiotic usage, hospitalizations, quantitative chest radiology, spirometry, and lung volume determinations. Obstructive lung disease was defined as percent predicted spirometry values below the lower limits of normal. Longitudinal analyses revealed no significant differences in cough, wheezing, respiratory infections, prevalence of and median times to acquisition of Pseudomonas aeruginosa or Staphylococcus aureus, antibiotic usage, and chest radiograph scores between the two groups. However, MI children showed significantly worse forced expiratory volume in 1 sec (FEV(1)), forced vital capacity (FVC), forced expiratory flow between 25-75% of FVC (FEF(25-75)), % predicted FEV(1), % predicted FEF(25-75), and total lung capacity (TLC). These differences were particularly apparent beginning at age 8-10 years. MI children also had higher rates of and shorter median times to obstructive lung disease. Subgroup analyses showed MI children treated surgically and those treated medically had similar pulmonary outcomes. In conclusion, MI children have worse lung function and more obstructive lung disease than those without MI. Such abnormalities are accompanied by reduced lung volume. MI is a distinct CF phenotype with more severe pulmonary dysfunction.     

Effects of bronchoscopy on lung function in asthmatics

Background: To better understand the changes in pulmonary physiology related to asthma severity following bronchoscopy, we performed scheduled pre- and post-procedure spirometry on subjects undergoing bronchoscopy in our research program. Methods: Control subjects and asthma subjects were recruited for bronchoscopy. On the day of bronchoscopy, subjects underwent spirometry pre-bronchoscopy and then up to three sets within 2 hour following the completion of bronchoscopy. A subset of patients had a second bronchoscopy after 2 weeks of treatment with oral prednisolone (40mg daily). Results: A total of 92 subjects had at least one bronchoscopy (12 control subjects, 56 nonsevere asthma (NSA), 24 severe asthma (SA)). The SA and NSA groups had similar decreases in forced expiratory volume in 1 second (FEV1) (?20±13% vs.?19±16%, p = 0.92) and forced vital capacity (FVC) (?20±12% vs.?20±14%, p = 0.80), but no change in FEV1/FVC ratio. The control and NSA group had more rapid recovery of both FEV1 and FVC by 2 hour compared to the SA group (p = 0.01). In the subset of 36 subjects (22 NSA, 14 SA) who underwent a second bronchoscopy following the administration of oral prednisolone for 14 days, steroids resulted in more rapid recovery of lung function (p < 0.04). Conclusion: Following bronchoscopy the lung function of NSA subjects recovered more quickly than SA subjects. Treatment with oral corticosteroids was associated with a quicker recovery of FEV1 which suggests an inflammatory mechanism for these changes in lung compliance.     

AECOPD氧化应激与肺功能、最大呼吸肌力动态变化相关性研究

目的 研究AECOPD患者氧化应激与肺功能、最大呼吸肌力动态变化的相关性.方法ELISA检测47例COPD急性加重期患者血清丙二醛(MDA)、谷胱甘肽(GSH)、氧化型谷胱甘肽(GSSG)、超氧化物歧化酶(SOD)浓度,与其第一秒钟用力呼气容积( FEV1)、用力肺活量(FVC)、最大吸气压(MIP)年下降值进行相关性分析.结果 MDA与FEV1年下降值呈正相关,GSH、GSH/GSSG与FEV1年下降值呈负相关,GSH与MIP年下降值呈负相关.结论 COPD急性加重期氧化/抗氧化失衡加速COPD的肺功能下降和呼吸肌力的减弱.     

COPD患者HMGB1与肺功能的相关性分析

目的研究COPD病人在急性加重期和临床缓解期血中高迁移率族蛋白B1（HMGB1）、肺功能的变化及其相关性分析。方法分别测定COPD病人在急性加重期和经过治疗进入临床缓解期血清HMGB1的浓度及肺功能值（FEV1%、FEV1/FVC）,数据用SPSS 13.0作统计分析。结果急性加重期HMGB1浓度值高于缓解期（P〈0.05）;急性加重期FEV1%低于缓解期（P〈0.05）;加重期和缓解期HMGB1浓度值和FEV1%呈直线负相关（P〈0.05）。结论 1.HMGB1作为炎性分子,在COPD急性加重期血清浓度显著高于缓解期。2.在COPD中HMGB1浓度和肺功能明显相关,提示对于疾病严重程度的判断可能有一定意义。     

Do NHLBI lung function criteria apply to children? A cross‐sectional evaluation of childhood asthma at National Jewish Medical and Research Center, 1999–2002

Although National Heart Lung Institute (NHLBI) guidelines categorize asthma severity based on spirometry, few studies have evaluated the utility of these spirometric values in grading asthma severity in children. Asthma is thought to be progressive, but little is known about the loss of lung function in childhood. This study sought to determine the spirometric indices in children from 4-18 years of age. Retrospective cross-sectional analysis was performed on all spirometries done in children at the National Jewish Medical and Research Center from 1999-2002. In total, 2,728 children performed 24,388 measures. The mean +/- SD values for forced vital capacity (FVC), forced expired volume in 1 sec (FEV(1)), FEV(1)/FVC ratio, and forced expiratory flow (FEF)(25-75) were 92.7 +/- 16.2, 92.2 +/- 18.0, 85.3 +/- 9.3, and 78.0 +/- 36.5 percent predicted, respectively. Seventy-seven percent of FEV(1) values were >/= 80%, 18.6% were between 60-80%, and 3.1% were <60% of predicted. FEV(1) was highest in 5-year-old children; it declined thereafter, reaching a nadir at 11 years, followed by a partial recovery from 12-18 years. Expressed in liters, FEV(1) values were lower than expected at every age, with the greatest difference at 18 years. FEV(1)/FVC ratios declined through childhood, suggesting impaired airway but not lung growth in children with asthma. In conclusion, the majority of asthmatic children attending a tertiary care facility had FEV(1) values within normal range. With increasing age, the increase in FEV(1) lags behind that of nonasthmatics, so that by 18 years, maximum FEV(1) is impaired. The NHLBI FEV(1) cutoff values do not appear to accurately stratify pediatric asthma, and no useful FEV(1) cutoff could be generated.     

哮喘儿童肺通气功能检测的临床分析

目的：通过监测哮喘儿童急性发作期与缓解期肺通气功能各指标变化情况,了解其在儿童哮喘病情评估及指导治疗中的作用。方法应用德国Jaeger Master Screen肺功能仪对43例5～12岁哮喘急性发作期和经治疗后进入缓解期的哮喘儿童进行肺通气功能检测,包括大气道指标（ FVC、FEVl、FEV1/FVC、PEF）及小气道指标（ FEF25、FEF50、FEF75、MMEF75/25）,同时收集哮喘患儿病史资料和治疗情况。结果哮喘急性发作期患儿肺功能指标FVC、FEV1、FEV1/FVC、PEF与缓解期及健康对照组儿童比较,差异有统计学意义（ P＜0.01）;哮喘缓解期患儿的FVC、FEV1、PEF与健康对照组比较,差异无统计学意义（ P＞0.05）。小气道功能指标FEF25、FEF50、FEF75、MMEF75/25在哮喘急性发作期患儿中均明显降低,与缓解期组及健康对照组儿童相比差异有统计学意义（ P＜0.01）;哮喘治疗缓解期组中FEF25、FEF50、FEF75、MMEF75/25仍低于健康对照组,差异有统计学意义（ P＜0.05）。哮喘急性发作期不同严重程度患儿的肺通气功能指标（ FVC％pred、FEV1％pred、PEF％pred、FEF25％pred、FEF50％pred、FEF75％pred、MMEF75/25％pred ）随哮喘严重程度增加各指标越低,差异有统计学意义（ P＜0.05）。结论哮喘急性发作期肺通气功能受损,治疗缓解后小气道肺功能指标仍低于正常。肺通气功能的小气道功能指标在儿童哮喘的病情评估及治疗监测指导中意义更大。     

慢性阻塞性肺疾病道炎症变化其与肺功能相关性研究

目的 观察慢性阻塞性肺疾病急性加重期(acute exacerbation of chronic obstructive pulmonary disease,AECOPD)患者气道炎症细胞及细胞因子的变化,探讨其与肺功能恶化的相关性.方法 取AECOPD患者及健康志愿者诱导痰作细胞学计数和分类;测定肺功能,检测诱导痰上清液的肿瘤坏死因子á(tumor necrosis factor-á,TNF-á)、白介素5(interleukin-5,IL-5)等细胞因子.结果 AECOPD组的诱导痰嗜酸粒细胞百分比、中性粒细胞百分比与正常对照组比较,差异有统计学意(P<0.01);与正常对照组比较,AECOPD诱导痰上清液TNF-á浓度差异有统计学意义(P相似文献   

综合排痰护理改善老年支气管哮喘急性发作期患者肺功能的研究

目的 探讨综合排痰护理对老年支气管哮喘急性发作期肺功能的影响,为寻求有效的护理手段提供依据。方法选择2011年11月至2013年4月老年支气管哮喘急性发作期住院患者100例,随机分为常规护理组（n=50）和排痰护理组（n=50）,常规护理组患者仅采用常规护理,排痰护理组在常规护理基础上再加综合排痰护理,连续7d。分别对2组患者的临床疗效、肺功能变化[（1秒用力呼气容积／用力呼气量预计值的百分比（FEV1％）,1秒用力呼气容积／用力肺活量百分比（FEV1／FVC）,最大呼气峰值流速实测值占预计值的百分比（PEF％）]等进行检测及统计分析。结果排痰护理纽显效29例、有效14例、无效7例、总有效率为86％,而常规护理组显效22例、有效15例、无效13例、总有效率为74％,排痰护理组总有效率高于常规护理组,但差异无统计学意义（P〉0．05）;与治疗前比较,2组治疗后FEV,％、FEV,／FVC和PEF％均明显升高（P〈0．05）;与常规护理组治疗后比较,排痰护理组治疗后的FEV1％、FEV1／FVC和PEF％皆显著升高,差异有统计学意义（P〈0．05）。结论 综合排痰护理对老年支气管哮喘急性发作期患者肺功能有较显著的改善效果。     

Spirometric values in Gypsy (Roma) children

Values of spirometry indices vary among subjects of similar age, gender and somatometrics but of different ethnic origins. Low socioeconomic status in childhood is inversely related to lung growth. The aim of this investigation was to assess spirometry values in Gypsy children and compare them to reported values for Caucasians. Gypsy students attending primary schools in Central Greece were recruited. Spirometry indices were measured using a portable spirometer. Regression analysis was applied to construct prediction equations for forced vital capacity (FVC) and other spirometric indices (FEV(1), FEF(50), FEF(25), FEF(25-75)) based on standing height. Predicted spirometric values were compared to values for Caucasians from published studies. In 152 children (ages 5-14 years; 57 girls) lung function increased linearly with height: spirometry index=intercept+[slopexheight], (r(2)=0.68 for FVC and FEV(1) in girls; r(2)=0.78 for FVC and r(2)=0.74 for FEV(1) in boys). Excluding boys-but not girls-in puberty increased fit for FVC (r(2)=0.83) and FEV(1) (r(2)=0.79). Mean predicted values were 5-10% lower than values for Caucasians. In Gypsy children, FVC and expiratory flow function increase linearly with standing height and predicted values are lower than those for Caucasians of similar height.     

Chronic graft-versus-host disease and pulmonary function.

Pulmonary complications are a major cause of morbidity and mortality in bone marrow transplant recipients. Earlier series, consisting mainly of adults, have shown evidence of obstructive changes of pulmonary functions in association with chronic graft-versus-host disease (CGVHD). We longitudinally evaluated spirometry in 46 patients who received bone marrow transplants as children or as young adults to determine whether they had similar abnormalities. Group mean FEV1/FVC, and percent predicted FVC, FEV1, and FEF25-75 values did not demonstrate obstructive changes in association with CGVHD in this patient population. Our findings suggest that younger patients with CGVHD, as a group, may fare better than older bone marrow transplant recipients with CGVHD. However, due to small sample sizes, it cannot be conclusively stated that the pulmonary function parameters analyzed do not differ in the two patient groups.     

Lung function, bronchial responsiveness, and asthma in a community cohort of 6-year-old children

Children as young as 6 years old can perform spirometry, yet the relationship between current asthma, lung function, and bronchial responsiveness has not been described at this age; 2,537 children from a community-based birth cohort were assessed at 6 years of age, with history (n = 2,141), physical examination (n = 1,995), standard spirometry (n = 1,735), and a random sample (n = 711) offered methacholine challenge. Males had greater values of FVC and FEV(1) but not of mean forced expiratory flow during the middle half of the FVC or FEV(1)/FVC than females. The greatest influences on lung function at 6 years were height, sex, birth weight, and wheezing in the first year of life. Children with current asthma had small but significant deficits in lung function and were more sensitive to methacholine. The optimal cutpoint for determining heightened bronchial responsiveness was found to be a 15% fall in FEV(1) at a dose of 1.8 mg/ml. A negative test could be useful in excluding a diagnosis of asthma (negative predictive value of 92%). Lung function testing, including methacholine challenge, is feasible in 5- to 7-year-old children and has the potential to contribute to the clinical management of children with asthma.Keywords:     

Respiratory symptoms and lung function in relation to atopy in children born preterm

Respiratory morbidity is a major health problem among children. The aim of this study was to compare the background of respiratory problems of children born preterm with that of children born full-term, with special reference to atopy. The study comprised two cohorts of 10-year-old children: a group of 72 children born preterm with birth weights of less than 1,501 g, and a group of 65 children born full-term with birth weights of over 2,500 g. Histories of respiratory and atopic symptoms, and of risk factors for atopy, were collected with a questionnaire. Predisposition to atopy was verified by skin-prick testing and by measuring serum total and antigen-specific IgEs. Lung function was evaluated by spirometry testing. Children born preterm had significantly more wheezing. In them, the lifetime prevalence of wheezing was 43%, vs. 17% in children born full-term (P = 0.001; odds ratio, 3.71; 95% confidence interval, 1.67-8.25). In the full-term group, wheezing was associated with atopy: 64% of wheezers were atopic; in the preterm group, 23% of wheezers were atopic (difference between groups, P = 0.024). Children born preterm expired significantly lower spirometry values of forced vital capacity (FVC), forced expiratory volume in 1 sec (FEV1), FEV1/FVC ratio, forced expiratory flow after 50% of vital capacity has been exhaled (FEF50), and forced expiratory flow during middle half of FVC (FEF25-75). In the preterm group, wheezing, asthma, and low gestational age, but not atopy, were significantly associated with lower lung function values. Wheezers of the preterm group who still wheezed at age 10 were significantly more often atopic than those who no longer wheezed (62% vs. 9%, P = 0.006). In conclusion, we demonstrated a significant difference between groups in the association of atopy with respiratory problems. However, although atopy was not associated with a lifetime prevalence of respiratory symptoms in prematurely born children, an atopic predisposition in them was found to associate with persistence of wheezing.     

慢性阻塞性肺疾病不同病程肺功能动态改变特点和机制的研究

目的　探讨慢性阻塞性肺疾病（COPD）急性加重期和稳定期肺功能的动态改变特点和机制。方法　对30例COPD患者分别于急性加重期和稳定期进行Borg气急指数评估、肺通气功能检测、肺容量检测、体积描记法总气道阻力（Rtot）测定和呼吸阻抗、呼吸阻力检测。结果　Borg气急指数稳定期较急性加重期显著下降（P〈0．001）。通气功能测定参数FVC、FVC／pre、FEVI、FEVI／pre和FEV1／FVC稳定期较急性加重期显著增加（P均〈0．05）。肺容量检测参数深吸气量（IC）稳定期较急性加重期显著增加（P〈0．001），胸腔内气体容积（ITGV）和残气量（RV）稳定期较急性加重期显著下降（P均〈0．05）。Rtot稳定期较急性加重期显著下降（P〈0．01）。IOS测定参数共振频率（Fres）、呼吸总阻抗（Z5）、总气道阻力（R5）、中央气道阻力（R20）和外周气道阻力（R5-R20）稳定期较急性加重期显著下降（P均〈0．05），5Hz时呼吸电抗（X5）稳定期较急性加重期显著增高（P〈0．001）。通气功能检测参数中FEV-改善率最高，肺容量检测IC改善率最高，呼吸阻抗和呼吸阻力检测R5—R20和X5改善率较高。IC、RV和ITGV稳定期较急性加重期的改善值与FVC的改善值显著相关（P均〈0．05），IC和RV稳定期的改善值与FEV-的改善值显著相关。Z5、R5、R5-R20、X5和Fres稳定期的改善值与通气功能参数FVC、FEV-和FEV-／FVC的改善值显著相关（P均〈0．05）。结论 COPD急性加重期较稳定期肺功能显著下降，肺过度充气和外周气道阻力增加是急性加重期肺功能恶化的主要原因。     

Spirometry reference values for Navajo children ages 6–14 years

Spirometry is the most important tool in diagnosing pulmonary disease and is the most frequently performed pulmonary function test. Since respiratory disease is the single greatest cause for morbidity and mortality on the Navajo Nation, the purpose of this study was to create new age and race‐specific pulmonary nomograms for Navajo children. Five hundred fifty‐eight healthy children, ages 6–14 years, attending Navajo Nation elementary schools in Arizona, were asked to perform spirometry to develop population‐specific and tribe‐specific nomograms for forced vital capacity (FVC), forced expiratory volume in 1 sec (FEV1), and FEV1 Ratio (FEV1/FVC). Spirometry tests from 284 girls and 274 boys met American Thoracic Society quality control standards. Lung function values, except for FEV1/FVC, all increased with height. The lower limit of the normal range for FEV1/FVC was 80%. The spirometry reference equations from the healthy boys and girls were developed. Height and the natural log of height were significant predictors of FEV1, FVC, and FEF_25–75% in the gender‐specific models. The resulting population‐specific spirometry reference equations should be used when testing Navajo children ages 6–14 years. However, the use of the NHANES III spirometry reference equations for Caucasian children may not result in significant misclassification in clinical settings providing that a maximal effort is given by the Navajo child being tested. Pediatr Pulmonol. 2009; 44:489–496. © 2009 Wiley‐Liss, Inc.     

儿童胸闷变异性哮喘肺功能改变的特征

目的探讨胸闷变异性哮喘患儿肺功能改变的特点,为临床诊断和管理提供依据。方法选取2018年8月至2019年5月确诊为胸闷变异性哮喘的44例患儿为研究对象,选取同期初诊的非急性发作期的典型哮喘患儿62例及健康体检儿童46例为对照组。所有入组儿童在初诊或体检时进行呼出气一氧化氮(fractional exhaled nitric oxide,FeNO)和肺通气功能的检测,胸闷变异性哮喘组和典型哮喘组行支气管激发试验。分析对比不同组患儿的FeNO水平、肺通气功能改变及气道高反应性严重程度。结果胸闷变异性哮喘组FeNO中位数值为14.0(8.0,24.0)ppb,其水平明显低于典型哮喘组[31.0(12.0,51.0)ppb,P<0.05],高于健康儿童组[9.0(7.0,18.5)ppb,P<0.05];胸闷变异型哮喘儿童肺通气功能参数中FEV1/FVC[0.998(0.967~1.079)]、PEF[(94.41±12.91)]、FEF50[79.15(64.78~93.75)]、FEF75[66.50(53.10~95.90)]均显著低于健康儿童组[1.080(1.039~1.103),P<0.01]、[(106.38±14.14),P<0.01]、[86.17(79.05~97.67),P<0.05]、[72.29(66.14~81.90),P<0.05],但与典型哮喘组无明显差异(P>0.05);胸闷变异性哮喘组第1秒用力呼气容积(FEV1)下降20%时吸入的乙酰甲胆碱累积剂量(PD20-FEV1)均值为(0.855±0.691)mg,显著高于典型哮喘组[(0.321±0.213)mg,P<0.01]。结论胸闷变异性哮喘患儿FeNO水平高于健康儿童,通气功能FEV1/FVC、PEF及小气道功能指标均低于健康儿童;胸闷变异性哮喘患儿肺通气功能与非急性发作期的典型哮喘患儿接近,但其FeNO水平及气道高反应性的程度均显著低于后者。     

Static lung volumes in patients with Cushing's disease.

OBJECTIVE: Numerous clinical manifestations have been described in association with Cushing's syndrome. There are no eligible data on pulmonary function tests in Cushing's disease (CD). We aimed to asses pulmonary function tests including spirometry in a series of patients with active CD. MATERIALS AND METHODS: This cross-sectional study comprised 10 patients with Cushing's disease (F/M, 9/1). The forced expiratory volume in 1st second (FEV1), the forced vital capacity (FVC), the FEV1/FVC ratio and the forced expiratory flow over the middle half of the FVC (FEF 25-75%) values and predicted values were determined by spirometry. RESULTS: Mean age, height, weight, body mass index were 36.7+/-12.6 yrs (range 22-63 years), 156.9+/-8.4 cm, 74.1+/-10.7 kg, 29.6+/-3.8 kg/m(2), respectively. Spirometric abnormalities (impairment of FEV1, FVC, FEV1/FVC and FEF 25-75 values) were not detected, and there were no significant differences compared to reference values. Disease duration and cortisol concentrations by HDDSTs were negatively correlated with predicted FEV1/FVC values and the percentage of predicted FEV1 ratios, respectively. DISCUSSION: The lung volume and ventilatory performance by spirometry were not disturbed in patients with endogenous hypercostisolism due to Cushing's disease.     

Spirometric pulmonary function in 3- to 5-year-old children

Forced expiratory maneuvers are routinely used in children, 6 years of age and older for the diagnosis and follow-up of respiratory diseases. Our objective was to establish normative data for an extensive number of parameters measured during forced spirometry in healthy 3- to 5-year-old children. Children aged between 3 and 5 years were tested in 11 daycare centers. Usual parameters, including FEV1, FVC, PEF, FEF(25-75), FEF25, FEF50, FEF75, and Aex were measured and analyzed in relation to sex, age, height, and weight. In addition, the same analysis was performed for FEV0.5 and FEV0.75. One hundred sixty-four children were recruited for testing including 87 girls and 77 boys. Thirty-five were 3 years old, 63 were 4 years old, and 66 were 5 years old. Overall, 143 children (87%) accepted to perform the test and 128 children (78%) were able to perform at least two technically acceptable expiratory maneuvers. Analyses using different regression models showed that height was the best predictor for every parameter. In conclusion, the present study confirms that most healthy 3-5 years old children can perform valid forced expiratory maneuvers. In agreement with other studies, we found that height is the most important single predictor of various parameters measured on forced spirometry. The present study is the first to establish normative values for FEV0.75, as well as to demonstrate that Aex can be easily performed in the majority of children aged 3-5 years. These are likely important parameters of lung function in this age range.     

Post-bronchodilator spirometry reference values in adults and implications for disease management

RATIONALE: International guidelines promote the use of post-bronchodilator spirometry values in the definition and severity classification of chronic obstructive pulmonary disease. However, post-bronchodilator reference values have not yet been developed. OBJECTIVES: To derive reference values for post-bronchodilator forced expiratory volume in one second (FEV1), forced vital capacity (FVC), and FEV1/FVC, and to compare these reference values with locally derived and existing pre-bronchodilator reference values. METHODS: Based on a random sample of a general adult population, 2,235 subjects (70% of invited subjects) performed spirometry with reversibility testing. A reference population of healthy never-smokers constituted 23% of the study population (n=515). Reference values for median and lower-limit-of-normal pre- and post-bronchodilator lung function and bronchodilator response were modeled using quantile regression analyses. MAIN RESULTS: The reference population had equal proportions of men and women in the age range 26-82 yr. Both FEV1 and FVC decreased with age and increased with height. FEV1/FVC decreased with age, although this trend was not statistically significant for men after bronchodilatation. Linear models gave the best overall fit. Lower-limit-of-normal post-bronchodilator FEV1/FVC exceeded 0.7 for both sexes. Post-bronchodilator prediction equations gave higher predicted FEV1 and FEV1/FVC than both locally derived and existing pre-bronchodilator equations. The bronchodilator response decreased with age. CONCLUSIONS: The present study is the first to develop reference values for post-bronchodilator lung function. Post-bronchodilator prediction equations can facilitate better management of patients with chronic obstructive pulmonary disease by avoiding falsely high FEV1% predicted with a subsequent underestimation of disease severity.