Quality of spirometry test performance in children and adolescents : experience in a large field study

The initial angle of the maximum expiratory flow-volume curve: a novel start-of-test criteria of spirometry in children

The aim of the present study was to define an initial angle called β and to assess its diagnostic value for identifying poor-quality maneuvers in spirometry testing in children. Furthermore, its predictive equation or normal value was explored. Children aged 4-14 years with respiratory symptoms who underwent spirometry were enrolled. Based on the efforts labeled during maneuvering and the quality control criteria of the guidelines, children were categorized into good-quality and poor-quality groups. According to ventilatory impairment, children in the good-quality group were divided into three subgroups: normal, restricted, and obstructed. Angle β was the angle between the line from the expiratory apex to the origin of coordinates and the x-axis of the maximal expiratory flow-volume (MEFV) curve. Demographic characteristics, angle β, and other spirometric parameters were compared among groups. The diagnostic values of angle β, forced expiratory time (FET), and their combination were assessed using receiver operating characteristic curves. Data from 258 children in the good-quality group and 702 healthy children in our previous study were used to further explore the predictive equation or normal value of angle β. The poor-quality group exhibited a significantly smaller angle β (76.44° vs. 79.36°; P < 0.001), significantly lower peak expiratory flow (PEF), FET, and effective FET (ETe), and significantly higher expiratory volume at peak flow rate (FEV-PEF) and ratio of extrapolated volume and forced vital capacity (EV/FVC) than the good-quality group. There was no significant difference in angle β among the normal, restricted, and obstructed groups. Logistic regression analysis revealed that smaller angle β and FET values indicated poor-quality MEFV curves. The combination of angle β < 74.58° and FET < 4.91 s had a significantly larger area under the curve than either one alone. The normal value of angle β of children aged 4-14 years was 78.40 ± 0.12°.   Conclusions: Angle β contributes to the quality control evaluation of spirometry in children. Both angle β < 74.58° and FET < 4.91 s are predictors of poor-quality MEFV curves, while their combination offers the highest diagnostic value. What is Known: • A slow start is one of the leading causes of poor-quality maximal expiratory flow-volume (MEFV) curves, which is a particularly prominent issue among children due to limited cooperation, especially those younger than 6 years old. • It is relatively difficult to differentiate between ventilatory dysfunction and poor cooperation when a slow start occurs in children; therefore, there is an urgent need for an objective indicator that is unaffected by ventilatory impairment to evaluate quality control of spirometry. What is New: • The initial angle β, which was introduced at the ascending limb of the MEFV curve in the present study, has a certain diagnostic value for poor-quality MEFV curves in children. • Angle β < 74.58° is a predictor of poor-quality MEFV curves, and its combination with FET < 4.91 s offers a higher diagnostic value.

Impact of pleural effusion at an early period after posterior spinal fusion for adolescent idiopathic scoliosis on future pulmonary function and lung volume

Background

Posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS) has a potential risk for postoperative pleural effusion. Although pleural effusion at an early period after PSF for AIS occurs with a relatively high frequency and occasionally requires some treatments, the impact of postoperative pleural effusion on future pulmonary function or lung volume (LV) has not been clarified to date. The aim of this study was to evaluate the effect of pleural effusion after PSF for AIS on the postoperative pulmonary function and LV.

Methods

A total of 114 consecutive patients who underwent PSF for AIS followed up greater than 2 years at our institute were retrospectively reviewed. We evaluated postoperative pleural effusion by computed tomography (CT) at the 1-week follow-up and divided patients into the pleural effusion (PF) and non-pleural effusion (NP) groups. We investigated spirometry parameters recorded for testing included vital capacity (VC), forced expiratory volume in the first second (FEV1), %VC, and FEV1% and measured the LV using CT images and a workstation at baseline and 2 years after surgery.

Results

A total of 87 (76.3%) patients with postoperative pleural effusion were identified, but all patients were asymptomatic and did not require additional treatment for postoperative pleural effusion. All pulmonary function parameters at the 2-year follow-up exhibited no significant differences between the two groups. Although preoperative left LV (1.21±0.30 L vs. 1.36±0.34 L; p=.022) and total LV (2.68±0.62 L vs. 2.99±0.73 L; p=.031) were significantly lower in the PF group than in the NP group, all postoperative LV parameters were similar between the two groups.

Conclusions

Pleural effusion at an early period after PSF for AIS was a postoperative occurrence without an impact on future pulmonary function and LV.

Associations between prenatal and early-life air pollution exposure and lung function in young children: Exploring influential windows of exposure on lung development

BACKGROUND

Evidence in the literature suggests that air pollution exposures experienced prenatally and early in life can be detrimental to normal lung development, however the specific timing of critical windows during development is not fully understood.

OBJECTIVES

We evaluated air pollution exposures during the prenatal and early-life period in association with lung function at ages 6-9, in an effort to identify potentially influential windows of exposure for lung development.

METHODS

Our study population consisted of 222 children aged 6-9 from the Fresno-Clovis metro area in California with spirometry data collected between May 2015 and May 2017. We used distributed-lag non-linear models to flexibly model the exposure-lag-response for monthly average exposure to fine particulate matter (PM2.5) and ozone (O3) during the prenatal months and first three years of life in association with forced vital capacity (FVC), and forced expiratory volume in the first second (FEV1), adjusted for covariates.

RESULTS

PM2.5 exposure during the prenatal period and the first 3-years of life was associated with lower FVC and FEV1 assessed at ages 6-9. Specifically, an increase from the 5th percentile of the observed monthly average exposure (7.55 μg/m3) to the median observed exposure (12.69 μg/m3) for the duration of the window was associated with 0.42 L lower FVC (95% confidence interval (CI): -0.82, -0.03) and 0.38 L lower FEV1 (95% CI: -0.75, -0.02). The shape of the lag-response indicated that the second half of pregnancy may be a particularly influential window of exposure. Associations for ozone were not as strong and typically CIs included the null.

CONCLUSIONS

Our findings indicate that prenatal and early-life exposures to PM2.5 are associated with decreased lung function later in childhood. Exposures during the latter months of pregnancy may be especially influential.

Spirometry quality predictors in a large multistate prospective study

BACKGROUND

The Gulf Long-Term Follow-up (GuLF) Study is a prospective cohort study of health effects associated with oil spill response and clean-up following the 2010 Deepwater Horizon Disaster (DWH). As part of the study, spirometry testing of lung function was carried out in home visits across multiple states. Few studies have described factors associated with spirometry test failure in field-based settings.

OBJECTIVE

Our objective was to identify what factors, if any, predict test failure among GuLF Study participants who completed spirometry testing in a non-traditional setting.

METHODS

Trained examiners administered spirometry (May 2011-May 2013) to 10,019 participants living in US Gulf States (LA, MS, TX, AL, FL) using an Easy-on ultrasonic spirometer. We applied American Thoracic Society/European Respiratory Society quality criteria to determine quality test failure and identified factors predictive of failure using both a Stepwise and a LASSO model. We calculated odds ratios and 95% confidence intervals (CIs) for associations of selected factors with test failure.

RESULTS

Among GuLF Study participants who conducted spirometry, self-reported African American/Black participants (OR: 1.39, 95% CI: 1.23,1.56); men (OR:1.61, 95% CI: 1.41,1.83); and those making less than $20,000 per year (OR: 1.45, 95% CI: 1.26,1.67) were more likely to fail quality testing, while those who were obese were less likely to fail (OR: 0.61, 95% CI: 0.42,0.89).

CONCLUSION

Field-based studies involving spirometry should identify and account for participant factors that may influence test failure. Coaching that is tailored to those less likely to have experience with spirometry may help reduce test failure rates.

Development and Validation of an Algorithm for Quality Grading of Pediatric Spirometry: A Quality Improvement Initiative

RATIONALE

Current spirometry quality grading for individuals 7 years and older include within test repeatability thresholds up to 250mls, which may be inappropriately wide for children.

OBJECTIVES

1) To develop, internally validate and implement a quality grading algorithm for FEV1 and FVC for school-age children 2) to compare the algorithm to the one proposed by the American Thoracic Society (ATS).

METHODS

We conducted a review of existing algorithms and obtained expert input. A pediatric quality grading algorithm was drafted and modified in an iterative process until consensus was achieved; the main difference to current criteria being tighter volume repeatability for the pediatric quality grading. Four pulmonary function technicians evaluated the inter-rater agreement of the algorithm in a blinded fashion on an unselected consecutive sample of 87 pre-bronchodilator spirometry tests, and the grades compared with the ATS algorithm in the same sample of spirometry tests. The algorithm was then implemented into the workflow of the pulmonary function laboratory.

RESULTS

For FEV1 and FVC, the inter-rater agreement for the Pediatric Algorithm was 92% and 83%, respectively. Using the ATS algorithm, 75.9% (n=66) and 63.2% (n=55) of subjects achieved grade A for FEV1 and FVC; using the Pediatric Algorithm, 69.0% (n=60) and 58.6% (n=51) achieved grade A criteria. There was a more uniform distribution of tests for the Pediatric Algorithm across grades B through F for FEV1 and FVC and no grade C tests were observed for the ATS grading algorithm. 2,464 tests graded prospectively using the Pediatric Algorithm showed a median (IQR) FEV1 and FVC repeatability of 29ml (13 to 57) and 34 ml (15 to 66), respectively. Most subjects received a grade A for FEV1 (81.1%) and FVC (71.6%), performing a repeatable spirometry test to within 100ml.

CONCLUSIONS

A quality grading algorithm that uses smaller ranges of expired volumes to define repeatability is feasible and may be more appropriate in a pediatric pulmonary function laboratory.

Pediatric Patients of Outreach Specialist Queensland Clinics Have Lung Function Improvement Comparable to That of Tertiary Pediatric Patients

BACKGROUND

Inequitable access to quality health care contributes to the known poorer outcomes of people living in regional/remote areas (compared with urban-based), especially for First Nations people. Integration of specialist outreach services within primary care is one strategy that can reduce the inequity when modeled to the needs and available resources of target communities.

RESEARCH QUESTION

To evaluate whether respiratory outreach clinics in regional and remote Queensland are as effective as tertiary respiratory services at improving the lung function of children.

STUDY DESIGN AND METHODS

From existing databases, we obtained spirometry data of children (aged 3-18 years) seen at Indigenous-focused outreach clinics in regional and remote Queensland and Brisbane-based pediatric tertiary hospitals over the same contemporary period (October 2010 to July 2019). We compared the change in spirometry z scores (Δz) at follow-up for both groups of children.

RESULTS

Lung function significantly improved in both groups: Tertiary hospital (n = 2,249; ΔzFEV₁ = 0.22, 95% CI, 0.17 to 0.27; ΔzFVC = 0.23, 95% CI, 0.18 to 0.28); outreach (n = 252; ΔzFEV₁ = 0.35, 95% CI, 0.22 to 0.48; ΔzFVC = 0.36, 95% CI, 0.23 to 0.50). No significant intergroup differences were found in ΔzFEV₁ (0.13; 95%CI, -0.02 to 0.28; P = .10) or ΔzFVC (0.14; 95% CI, -0.02 to 0.29; P = .08) improvement from baseline. In both groups, the proportion of children with zFEV₁ > 0 at follow-up (hospital = 31.7%; outreach = 46.8%) significantly increased (hospital P = .001; outreach P = .009) from baseline (hospital = 27.2%; outreach = 35.3%). Numbers of children with zFEV₁ > 0 significantly increased for asthma and bronchiectasis outreach subgroups, and for children with asthma in the hospital-based group.

INTERPRETATION

Comparable significant lung function improvement of children was seen in Indigenous-focused outreach remote/regional clinics and paediatric tertiary hospitals. This suggests that effective clinical care is achievable within the outreach setting.

Culturally Appropriate Outreach Specialist Respiratory Medical Care Improves the Lung Function of Children in Regional and Remote Queensland

BACKGROUND AND OBJECTIVES

Indigenous Respiratory Outreach Care (IROC) is a culturally appropriate specialist respiratory service established to deliver multidisciplinary respiratory care to regional and remote Queensland communities. Our objective was to evaluate the impact of an outreach specialist respiratory service on the spirometry of children attending IROC clinics, particularly Indigenous children with asthma and bronchiectasis.

METHODS

Retrospective single-arm cohort study of 189 children who performed spirometry at twelve sites across regional and remote Queensland between October 2010 and December 2017. Each child's baseline spirometry was compared to their best spirometry at follow-up visit occurring within (1) 12 months of their most recent visit with at least 12 months of specialist care and; (2) each year of their first 3 years of care.

RESULTS

Forced expiratory volume in one second (FEV₁) and forced vital capacity (FVC) z-scores improved significantly across the whole group from baseline to follow-up (change in z-scores (Δz) of FEV₁ = 0.38, 95% CI 0.22, 0.53; ΔzFVC = 0.36, 95% CI 0.21, 0.51). In subgroup analyses, lung function significantly improved in Indigenous children (n = 141, ΔzFEV₁ = 0.37, 95% CI 0.17, 0.57; ΔzFVC = 0.36, 95% CI 0.17, 0.55) including those with asthma (n = 117, ΔzFEV₁ = 0.41, 95% CI 0.19, 0.64; ΔzFVC = 0.46, 95% CI 0.24, 0.68) and bronchiectasis (n = 38, ΔzFEV₁ = 0.33, 95% CI 0.07, 0.59; ΔzFVC = 0.26, 95% CI - 0.03, 0.53). Significant improvements in FEV₁ and FVC were observed within the first and second year of follow-up for Indigenous children, but not for non-Indigenous children.

CONCLUSION

The IROC model of care in regional and remote settings leads to significant lung function improvement in Indigenous children with asthma and bronchiectasis.

Prediction of therapeutic response before and during i.v. cyclophosphamide pulse therapy for interstitial lung disease in systemic sclerosis: A longitudinal observational study

There have been no established parameters to predict responsiveness to i.v. cyclophosphamide (IVCY) pulse therapy in combination with corticosteroids in patients with interstitial lung disease (ILD) related to systemic sclerosis (SSc). This retrospective study was conducted to determine predictive factors for efficacy of IVCY at the time of before and during the treatment. Thirty-two Japanese SSc patients, ever treated for ILD with IVCY in combination with prednisolone, were analyzed retrospectively. We performed detailed time-course analyses of parameters derived from blood samples and pulmonary function tests. With the exclusion of eight unclassified patients, 24 patients were classified into 14 good responders (GR) or 10 poor responders (PR) on the basis of changes in percent predicted diffusing capacity for carbon monoxide (DLco). Pretreatment percent predicted DLco was significantly reduced in PR compared with GR. In addition, serum parameters such as Krebs von den Lungen-6 (KL-6), surfactant protein D (SP-D) and C-reactive protein were significantly higher in PR than in GR. Furthermore, our time-course analyses revealed a transient increase in serum KL-6 levels with a peak at 3 months after the first infusion of cyclophosphamide, which showed no relation to therapeutic efficacy. Moreover, continuously high serum KL-6 levels (>2000 U/mL) and rapid decrease in SP-D levels (<200 ng/mL) during IVCY were remarkably characteristic of PR and GR, respectively. ILD severity/activity before treatment and variability of serum KL-6 and SP-D levels during treatment may be useful to predict therapeutic effects of IVCY on SSc-ILD.

Abnormal lung function at preschool age asthma in adolescence?

BACKGROUND

Asthma often begins early in childhood. However, the risk for persistence is challenging to evaluate.

OBJECTIVE

This longitudinal study relates lung function assessed with impulse oscillometry (IOS) in preschool children to asthma in adolescence.

METHODS

Lung function was measured with IOS in 255 children with asthma-like symptoms aged 4-7 years. Baseline measurements were followed by exercise challenge and bronchodilation tests. At age 12-16 years, 121 children participated in the follow-up visit, when lung function was assessed with spirometry, followed by a bronchodilation test. Asthma symptoms and medication were recorded by a questionnaire and atopy defined by skin prick tests.

RESULTS

Abnormal baseline values in preschool IOS were significantly associated with low lung function, the need for asthma medication, and asthma symptoms in adolescence. Preschool abnormal R5 at baseline (z-score ≥1.645 SD) showed 9.2 odds ratio (95%CI 2.7;31.7) for abnormal FEV1/FVC, use of asthma medication in adolescence, and 9.9 odds ratio (95%CI 2.9;34.4) for asthma symptoms. Positive exercise challenge and modified asthma-predictive index at preschool age predicted asthma symptoms and the need for asthma medication, but not abnormal lung function at teenage.

CONCLUSION

Abnormal preschool IOS is associated with asthma and poor lung function in adolescence and might be utilised for identification of asthma persistence.

Impact of a Pharmacist-driven Spirometry Clinic Service within a Community Family Health Center: A 5-year Retrospective Review

Objective:

This study was designed to describe the impact of a trained pharmacist in performing quality spirometry testing within a community family health center.

Methods:

This was a retrospective, cohort study of 150 physician-referred patients who attended their scheduled spirometry office appointment between November 2008 and December 2013. Information obtained included type of the disease (patients with obstructive or restrictive pulmonary disease), calculated lung age decline due to smoking history, quality of spirometry testing, and percentage of patients requiring pulmonary drug regimen alterations due to spirometry results. Pearson correlation and descriptive statistics were used to address study objectives.

Findings:

Spirometry testing performed by a pharmacist resulted in 87% of tests meeting guidelines for quality. Testing identified patients with reversible airway disease (39%), chronic obstructive pulmonary disease (21%), restrictive (11%), and mixed obstructive/restrictive (11%) lung defect. Patients with abnormal spirometry demonstrated a greater smoking pack-year history and calculated lung age than patients with normal spirometry (29.1 pack-years vs. 17 pack-years; P = 0.024 and 76.3 years vs. 54.6 years; P < 0.001, respectively). A weak correlation was found between a 29.1 smoking pack-year history and forced vital capacity (r = −0.3593, P = 0.018). The pharmacist assisted in modifying pulmonary drug regimens in 69% of patients based on evidence-based guidelines.

Conclusion:

A pharmacist-driven spirometry service was associated with quality testing results, identified respiratory disease abnormalities, and helped modifications of pulmonary drug regimens based on evidence-based guidelines. Future direction of this service may include collaborative practice agreements with physicians to expand services of pharmacists to include spirometry testing.

A primary care-based asthma program improves recognition and treatment of persistent asthma in inner-city children compared to routine care

OBJECTIVE

To examine whether a primary care-based asthma program that applies the Expert Panel Report 3 (EPR-3): Guidelines for the Diagnosis and Management of Asthma-2007 criteria to classify asthma severity increases detection of persistent asthma in inner-city children and affects "step of care" compared to routine care.

METHODS

A retrospective chart review was conducted of 97 consecutive children referred to the asthma program from 2011-2013. Asthma severity documented during routine health care maintenance visits was compared to the asthma severity assessed during the asthma program visit using five standardized questions and spirometry. Medication plan "step of care" was compared pre- and post- the asthma program visit.

RESULTS

79 children, ages 5-19 years old (mean = 9.6), had spirometry tracings meeting American Thoracic Society criteria and were included in this study. 53% were male. The majority of children were Latino (45.6%) or African American (35.4%). At the asthma program visit, more children were identified with moderate or severe persistent asthma based upon clinical questions (47.9%), spirometry (56.9%) or combined criteria (75.3%) than had been identified during routine care (15.2%); all p < .05. After the asthma program visit, more children were prescribed controller medications (82.3% vs 63.3%; p < .05) and 40.6% had their medication plan stepped up.

CONCLUSIONS

In this population of inner-city children, asthma severity was under-recognized and undertreated during routine care. A primary care based asthma program, which formalized applying EPR-3 criteria, increased detection of persistent asthma and led to "step-ups" in treatment plans.

Mismatch between asthma symptoms and spirometry: implications for managing asthma in children

OBJECTIVES

To examine the concordance between spirometry and asthma symptoms in assessing asthma severity and beginning therapy by the general pediatrician.

STUDY DESIGN

Between 2008 and 2012, spirometry testing was satisfactorily performed in 894 children (ages 5-19 years) whose asthma severity had been determined by their pediatrician using asthma guideline-based clinical criteria. Spirometry-determined asthma severity using national asthma guidelines and clinician-determined asthma severity were compared for concordance using weighted Kappa coefficients.

RESULTS

Thirty percent of participants had clinically determined intermittent asthma; 32%, 33%, and 5% had mild, moderate, and severe, persistent asthma, respectively. Increasing disease severity was associated with decreases in the forced expiratory volume in 1 second/forced vital capacity (FVC) ratio (P < .001), the forced expiratory volume in 1 second/FVC% predicted (P < .0001), and the FVC% predicted (P < .01). In 319 children (36%), clinically determined asthma severity was lower than spirometry-determined severity. Concordance was 0.16 (95% CI 0.10, 0.23), and when adjusted for bias and prevalence, was 0.20 (95% CI 0.17, 0.23). When accounting for age, sex, exposure to smoke, and insurance type, only spirometry-determined asthma severity was a significant predictor of agreement (P < .0001), with worse agreement as spirometry-determined severity increased.

CONCLUSIONS

Concordance between spirometry and asthma symptoms in determining asthma severity is low even when guideline-based clinical assessment tools are used. Because appropriate therapy reduces asthma morbidity and is guided by disease severity, results from spirometry testing could better guide pediatricians in determining appropriate therapy for their patients with asthma.

Early Onset Scoliosis: A Pulmonary Perspective

Early-onset scoliosis impairs lung function, often severely as it progresses. This review depicts current understanding of the changes in respiratory function resulting from early-onset scoliosis and how pulmonologists and their assessment tools affect clinical treatment decisions by spine surgeons.

Pulmonary function testing in children and infants

Pulmonary function testing is performed in children and infants with the aim of documenting lung development with age and making diagnoses of lung diseases. In children and infants with an established lung disease, pulmonary function is tested to assess the disease progression and the efficacy of therapy. It is difficult to carry out the measurements in this age group without disturbances, so obtaining results of good quality and reproducibility is challenging. Young children are often uncooperative during the examinations. This is partly related to their young age but also due to the long testing duration and the unpopular equipment. We address a variety of examination techniques for lung function assessment in children and infants in this review. We describe the measuring principles, examination procedures, clinical findings and their interpretation, as well as advantages and limitations of these methods. The comparability between devices and centres as well as the availability of reference values are still considered a challenge in many of these techniques. In recent years, new technologies have emerged allowing the assessment of lung function not only on the global level but also on the regional level. This opens new possibilities for detecting regional lung function heterogeneity that might lead to a better understanding of respiratory pathophysiology in children.

Researching asthma across the ages: insights from the National Heart, Lung, and Blood Institute's Asthma Network

Clinical asthma studies across different age groups (ie, cross-age studies) can potentially offer insight into the similarities, differences, and relationships between childhood and adult asthma. The National Institutes of Health's Asthma Research Network (AsthmaNet) is unique and innovative in that it has merged pediatric and adult asthma research into a single clinical research network. This combination enhances scientific exchange between pediatric and adult asthma investigators and encourages the application of cross-age studies that involve participants from multiple age groups who are generally not studied together. The experience from AsthmaNet in the development of cross-age protocols highlights some of the issues in the evaluation of cross-age research in asthma. The aim of this review is to summarize these challenges, including the selection of parallel cross-age clinical interventions, identification of appropriate controls, measurement of meaningful clinical outcomes, and various ethical and logistic issues.

Spirometric reference values in urban children in Madagascar: poverty is a risk factor for low lung function

BACKGROUND

Studies about children with respiratory diseases in Africa are impeded by the dearth of reliable data for the vast majority of countries on the continent. This study was conducted to establish representative reference values, therefore allowing a more accurate evaluation of lung function in Malagasy children.

METHODS

One thousand two hundred thirty-six students from three public and five private schools aged 8-12 years were recruited. A total of 1,093 children were healthy, had a valid lung function measurement and were thus deemed evaluable for this study. Lung function data were collected on consecutive days in Antananarivo, Madagascar's capital, using spirometry and a modified International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire.

RESULTS

The lung volumes found were substantially lower compared to Caucasian and African equations. The mean Z-score (Stanojevic) for the forced vital capacity (FVC) found was -1.45 and -0.93 for the forced expiratory volume in 1 sec (FEV1) with significant differences between private and public schools (FVC: P = 0.0023, FEV1: P = 0.0004).

CONCLUSIONS

The equations established for school children in Madagascar's capital Antananarivo showed lung function values were lower than reference values for the same age group seen not only in European, but also in African American and African children. The unique ethnicity of the Malagasy people, which combines Southeast-Asian with substantial African influences, the heavy burden of pollution and poverty may explain these differences.

Quality of spirometry in 5-to-8-year-old children

INTRODUCTION

Although spirometry quality standards for children were proposed by American Thoracic Society/European Respiratory Society (ATS/ERS) in 2007, there is limited information on the percentage of children that fulfill these criteria during routine clinical testing, especially among 5-to-8-year-olds.

AIMS OF THE STUDY

to report the percentage of children that met the current 2007 ATS/ERS quality criteria; explore factors potentially associated with poor quality spirometry; and ascertain the repeatability of forced expiratory volume at 0.5 sec (FEV0.5 ), and at 1 sec (FEV1 ), as well as forced vital capacity (FVC).

METHODS

We evaluated the quality of spirometries without bronchodilator use performed at our laboratory in 2008 by 5-to-8-year-old children. FEV1 , FEV0.5 , FVC, back-extrapolated volume (BEV), forced expiratory time (FET), number of acceptable maneuvers, and repeatability, were computed and the percentage of tests that met the quality criteria standards was calculated. Based on our results, we propose a quality scoring system for spirometry for children that grades on a scale from A-to-F.

RESULTS

Three hundred seventy-six spirometries were reviewed. Mean age was 6.7 years; (53% males); 68% fulfilled the 2005 and 2007 ATS/ERS quality standards; >90% reached a repeatability ≤150 and ≤100 ml, or 10%, in FVC or FEV1 ; 87.2% reached FET ≥3 sec; 88% had a BEV ≤80 ml. The 90 percentile repeatability was 120 ml for FVC and FEV1 . Quality improved with age.

CONCLUSIONS

Our results support the proposal that a FET ≥3 sec, a BEV ≤80 ml, and repeatability in FEV1 and FVC ≤100 ml, or 10%, be taken into account as elements in quality control for spirometry in children.

Diagnosis of hidden bronchial obstruction using computer-assessed tracheal forced expiratory noise time

BACKGROUND AND OBJECTIVE

Increased forced expiratory time was first recognized as a marker of obstruction half a century ago. However, the reported diagnostic capabilities of both auscultated forced expiratory time (FET(as)) and spirometric forced expiratory time are contradictory. Computer analysis of respiratory noises provides a precise estimation of acoustic forced expiratory noise time (FET(a)) being the object-measured analogue of FET(as). The aim of this study was to analyse FET(a) diagnostic capabilities in patients with asthma based on the hypothesis that FET(a) could reveal hidden bronchial obstruction.

METHODS

A group of asthma patients involved 149 males aged 16-25 years. In this group, 71 subjects had spirometry features of bronchial obstruction, meanwhile, the remaining 78 had normal spirometry. A control group involved 77 healthy subjects. Spirometry and forced expiratory tracheal noise recording were sequentially measured for each participant. FET(a) values were estimated by means of a developed computer procedure, including bandpass filtration (200-2000 Hz), waveform envelope calculation with accumulation period of 0.01 s, automated measurement of FET(a) at 0.5% level from the peak amplitude.

RESULTS

Specificity, sensitivity and area under Receiver Operating Characteristic curve of FET(a) and its ratios to squared chest circumference, height, weight were indistinguishable with baseline spirometry index FEV1 /forced vital capacity. Meanwhile, acoustic features of obstruction were revealed in 41%-49% of subgroup of patients with asthma but normal spirometry.

CONCLUSIONS

FET(a) of tracheal noise and its ratio to anthropometric parameters seem to be sensitive and specific tests of hidden bronchial obstruction in young male asthma patients.

Regression equations for peak expiratory flow in healthy children aged 7 to 14 years from Punjab, India

Background:

Measurement of peak expiratory flow (PEF) is imperative for management and evaluation of asthmatic children. It is well-known that lung function parameters show wide variations with respect to regional, racial, and genetic factors.

Aim:

This study was conducted to measure PEF in healthy Punjabi children aged 7-14 years as only a few studies have evaluated the lung functions in North Indian children.

Materials and Methods:

A cross-sectional study was conducted in which PEF was measured in 366 healthy schoolchildren (186 boys and 180 girls) of Patiala district, using the Mini Wright Peak Flow Meter. Best of the three trials was recorded. All the subjects were tested in standing position after recording their age, height, and weight. SPSS v. 13 was used for the statistical analysis.

Results:

The present study showed that all the three independent variables (age, height, and weight) had a significant positive correlation with PEF, in both genders. Furthermore, height was maximally correlated with PEF in both boys (r = 0.970) and girls (r = 0.964). The mean PEF value in boys (249.34 ± 81.36 L/min) was significantly higher than girls (233.31 ± 67.06 L/min). Regression equations for PEF were also determined using age, height, and weight, separately for the genders.

Conclusion:

Equations derived from this study for estimation of expected PEF values would help the clinicians in assessing the airway obstruction in this population subset.

R, Mohesh M.I. G, Kumar M. P. Effect of cigarette and cigar smoking on peak expiratory flow rate

BACKGROUND

Tobacco smoking in India has been increasing alarmingly. Smoking is a known risk factor for chronic obstructive pulmonary disease (COPD), cardiovascular diseases and certain cancers, especially, the lung cancer. The percentage prevalence of cigarette smoking (18.5%) and cigar smoking (4%) in males is high in Andhra Pradesh compared to other southern states. There is not enough scientific literature to correlate about intensity of cigarette and cigar smoking and their impact on lung function though high prevalence is reported in Andhra Pradesh, India.

OBJECTIVES

The purpose of this study was to examine whether PEFR differs between cigarette and cigar smokers compared to non-smokers and also to estimate the intensity of cigarette and cigar smoking on PEFR.

METHODS

PEFR was recorded in cigarette smokers (n=49) and cigar smokers (n=10) as well as in non-smokers (n=64) using Wright's mini Peak Flow Meter.

RESULTS

PEFR is decreased in both cigarette as well in cigar smokers compared to non-smokers and the magnitude of decline was higher in cigar smoking elderly individuals.

CONCLUSION

The intensity of cigarette and cigar smoking (pack-years) emerged as the main variable to influence airway obstruction in smokers that caused greater reduction in PEFR.

Oscillometric and spirometric bronchodilator response in preschool children with and without asthma

BACKGROUND

Bronchodilator responses (BDR) are routinely used in the diagnosis and management of asthma; however, their acceptability and repeatability have not been evaluated using quality control criteria for preschool children.

OBJECTIVES

To compare conventional spirometry with an impulse oscillometry system (IOS) in healthy and asthmatic preschool children.

METHODS

Data from 30 asthmatic children and 29 controls (two to six years of age) who underwent IOS and spirometry before and after salbutamol administration were analyzed.

RESULTS

Stable asthmatic subjects significantly differed versus controls in their spirometry-assessed BDR (forced expiratory volume in 1 s [FEV1], forced vital capacity and forced expiratory flow at 25% to 75% of forced vital capacity) as well as their IOS-assessed BDR (respiratory resistance at 5 Hz [Rrs5], respiratory reactance at 5 Hz and area under the reactance curve). However, comparisons based on the area under the ROC curve for &Delta;FEV1 %initial versus &Delta;Rrs5 % initial were 0.82 (95% CI 0.71 to 0.93) and 0.75 (95% CI 0.62 to 0.87), respectively. Moreover, the sensitivity and specificity for &Delta;FEV1 >=9% were 0.53 and 0.93, respectively. Importantly, sensitivity increased to 0.63 when either &Delta;FEV1 >=9% or &Delta;Rrs5 >=29% was considered as an additional criterion for the diagnosis of asthma.

CONCLUSION

The accuracy of asthma diagnosis in preschool children may be increased by combining spirometry with IOS when measuring BDR.

Comparison of Reference Values and Short-Term Variability for Oscillatory and Spirometric Lung Function in Healthy Korean Preschool Children

Respiratory function measurements are important in the diagnosis and follow-up assessment of respiratory diseases. The aims of this study were to establish reference values for spirometry, to compare them with respiratory resistance and impedance by an impulse oscillometry system (IOS), and to analyze 3-month follow-up studies in healthy Korean preschool children. Six hundred seven questionnaires were distributed and 497 (82%) were returned. Lung function tests were performed in 183 healthy children of the age of 3-6 years. The 3-month follow-up studies were conducted from 19 children who visited our clinic twice. Of the 183 children who underwent both IOS and spirometry, 164 (90%) and 150 (82%) met the quality-control criteria for IOS and spirometry, respectively. The regression equations of each spirometric parameter were obtained. Height was the most consistently correlated measurement in both boys and girls. All spirometry parameters, except for FEF_25-75/FVC, were significantly correlated with IOS parameters. There were no significant differences in respiratory resistance at 5 Hz measured by IOS (Rrs_IOS5), forced vital capacity (FVC), and forced expiratory volume in 1 s (FEV₁) between the first and second sets. The intraclass correlation coefficients and relative coefficients of repeatability for FEV₁, Rrs_IOS5, and respiratory system reactance (Xrs)_IOS5 were 0.90 (95% CI 0.73-0.96), 0.82 (95% CI 0.53-0.93), and 0.55 (95% CI -0.17-0.83) and 22.6%, 35.5%, and 91.8%, respectively. The obtained values and regression equations provide a reference for Korean preschool children and may be of importance in evaluating lung function of preschool children with pulmonary problems. Respiratory resistance and FEV₁ for healthy young Korean children are lower than literature reported reference values for Caucasian children. Rrs_IOS5 appears to be more stable on repeat testing than Xrs_IOS5.

Spirometry in primary care: an analysis of spirometery test quality in a regional primary care asthma program

BACKGROUND

Primary care office spirometry can improve access to testing and concordance between clinical practice and asthma guidelines. Compliance with test quality standards is essential to implementation.

OBJECTIVE

To evaluate the quality of spirometry performed onsite in a regional primary care asthma program (RAP) by health care professionals with limited training.

METHODS

Asthma educators were trained to perform spirometry during two 2 h workshops and supervised during up to six patient encounters. Quality was analyzed using American Thoracic Society (ATS) 1994 and ATS⁄European Respiratory Society (ERS) 2003 (ATS⁄ERS) standards. These results were compared with two regional reference sites: a primary care group practice (Family Medical Centre [FMC], Windsor, Ontario) and a teaching hospital pulmonary function laboratory (London Health Sciences Centre [LHSC], London, Ontario).

RESULTS

A total of 12,815 flow-volume loops (FVL) were evaluated: RAP - 1606 FVL in 472 patient sessions; reference sites - FMC 4013 FVL in 573 sessions; and LHSC - 7196 in 1151 sessions. RAP: There were three acceptable FVL in 392 of 472 (83%) sessions, two reproducible FVL according to ATS criteria in 428 of 469 (91%) sessions, and 395 of 469 (84%) according to ATS⁄ERS criteria. All quality criteria - minimum of three acceptable and two reproducible FVL according to ATS criteria in 361 of 472 (77%) sessions and according to ATS⁄ERS criteria in 337 of 472 (71%) sessions. RAP met ATS criteria more often than the FMC (388 of 573 [68%]); however, less often than LHSC (1050 of 1151 [91%]; P<0.001).

CONCLUSIONS

Health care providers with limited training and experience operating within a simple quality program achieved ATS⁄ERS quality spirometry in the majority of sessions in a primary care setting. The quality performance approached pulmonary function laboratory standards.

Spirometry testing in a population of Italian children: age and gender differences

AIM

To estimate how many asthmatic children underwent spirometry testing in one year in a large Italian region, and evaluate sociodemographic determinants.

METHODS

Data were retrieved from the administrative databases that store all pharmacological and diagnostic prescriptions issued to individuals living in the Lombardy Region. The analysis involved prescriptions dispensed to all 6-17 year olds (1,047,241 subjects) during 2008. Youths were identified as asthmatics by a previously validated strategy. Number of subjects having ≥1 spirometry claims was calculated, and factors associated with the probability of undergoing spirometry were evaluated by multivariate analysis.

RESULTS

A total of 40,528 (3.9%) asthmatic subjects were identified. Only 30% of them underwent ≥1 spirometry during 2008, with differences between local health units (range 22-45%) and degree of anti-asthmatic use (26-35%). Moreover, in a multivariate analysis, the chance of undergoing spirometry was greater in boys than in girls (OR=2.3).

CONCLUSIONS

A low percentage of asthmatic children, especially girls (who are more at risk of developing severe disease in adulthood), underwent spirometry during 1-year period. This highlights a low compliance with guidelines in the monitoring of childhood asthma. Educational intervention is needed in order to encourage use of spirometry in primary care settings.

Pulmonary functions of children with asthma improve following massage therapy

OBJECTIVES

This study aimed at evaluating the effect of massage therapy on the pulmonary functions of stable Egyptian children with asthma.

DESIGN

This study was an open, randomized, controlled trial.

SETTINGS/LOCATION

The study was conducted in pediatric allergy and chest unit of the New Children's Hospital of Cairo University, Egypt.

SUBJECTS AND INTERVENTIONS

Sixty (60) children with asthma were divided randomly into two equal groups: massage therapy group and control group. Subjects in the massage therapy group received a 20-minute massage therapy by their parents at home before bedtime every night for 5 weeks in addition to the standard asthma treatment. The control group received the standard asthma treatment alone for 5 weeks.

OUTCOME MEASURES

Spirometry was performed for all children on the first and last days of the study. Forced expiratory flow in first second (FEV1), forced vital capacity (FVC), FEV1/FVC and peak expiratory flow (PEF) were recorded.

RESULTS

At the end of the study, mean FEV1 of the massage therapy group was significantly higher than controls (2.3-0.8 L versus 1.9-0.9 L, p=0.04). There was no significant difference in FVC (2.5-0.8 L versus 2.7-0.7 L, p=0.43). However, FEV1/FVC ratio showed a significant improvement in the massage therapy group (92.3-21.5 versus 69.5-17, p<0.01). PEF difference was not significant (263.5-39.6 L/minute versus 245.9-32 L/minute, p=0.06).

CONCLUSIONS

A beneficial role for massage therapy in pediatric asthma is suggested. It improved the key pulmonary functions of the children, namely, FEV1 and FEV1/FVC ratio. However, further research on a larger scale is warranted.

Pulmonary function in children with development coordination disorder

The purpose of this study was to compare pulmonary function in children with developmental coordination disorder (DCD) with children who are typically developing (TD), and also analyze possible gender differences in pulmonary function between these groups. The Movement ABC test was used to identify the movement coordination ability of children. Two hundred and fifty participants (90 children with DCD and 160 TD children) aged 9-10 years old completed this study. Using the KoKo spirometry, forced vital capacity (FVC) and forced expiratory volume in 1s (FEV(1.0)) were used to measure pulmonary function. The 800-m run was also conducted to assess cardiopulmonary fitness of children in the field. There was a significant difference in pulmonary function between TD children and those with DCD. The values of FVC and FEV(1.0) in TD children were significantly higher than in children with DCD. A significant, but low correlation (r = -0.220, p < .001) was found between total score on the MABC and FVC; similarly, a positive but low correlation (r = 0.252, p < .001) was found between total score on the MABC and the completion time of 800-m run. However, no significant correlation between FVC and the time of 800-m run was found (p > .05). Significant correlations between total score on the MABC and the completion time of the 800-m run (r = 0.352, p < .05) and between FVC and the time of 800-m run (r = -0.285, p < .05) were observed in girls with DCD but not boys with this condition. Based on the results of this study, pulmonary function in children with DCD was significantly lower than that of TD children. The field test, 800-m run, may not be a good indicator to distinguish aerobic ability between children with DCD and those who are TD. It is possible that poor pulmonary function in children with DCD is due to reduced physical activity in this population.

Função pulmonar em portadores de anemia falciforme

OBJETIVO: Avaliar a função ventilatória por meio de espirometria, em escolares e adolescentes com anemia falciforme (AF), relacionando os achados a parâmetros clínicos e hematológicos. MÉTODOS: Foram avaliados portadores de AF de ambos os gêneros, a partir dos dez anos, clinicamente estáveis, sem intercorrências agudas, que foram submetidos à espirometria e avaliados quanto à saturação transcutânea de oxigênio, níveis de hemoglobina e contagem de leucócitos. Verificou-se a associação de alterações à espirometria com as características demográficas, clínicas e laboratoriais dos pacientes analisados. Para a análise estatística, aplicou-se o teste do qui-quadrado e o teste t para amostras não pareadas, sendo significante p<0,05. RESULTADOS: Foram estudados 51 pacientes e, em 40 (78%), identificou-se comprometimento do perfil espirométrico, do quais 20 (50%) apresentaram distúrbio ventilatório misto ou combinado, 13 (33%) mostraram perfil restritivo clássico e sete (18%), distúrbio ventilatório obstrutivo. Dos sete, em cinco (71%) observou-se resposta broncodilatadora positiva. A contagem total de leucócitos associou-se à função pulmonar alterada. O volume expiratório forçado no primeiro segundo sem broncodilatador, a capacidade vital forçada antes e após broncodilatador e o fluxo expiratório forçado entre 25 e 75% da capacidade vital forçada após broncodilatador foram significativamente menores nos pacientes com relato de internação hospitalar prévia por doença pulmonar aguda. CONCLUSÕES: A maioria dos pacientes apresentou alteração da função pulmonar, predominando o padrão misto ou combinado, seguido pelo restritivo clássico. Presença de leucocitose, na ausência de intercorrências agudas, associou-se a comprometimento de função pulmonar.

Impact of early childhood air pollution on respiratory status of school children

INTRODUCTION

In previous papers we analysed the incidence of wheezing in young children living near the iron and steel factory in Călăraşi, and in a control region (Roseţi) without industrial air pollution.

RESEARCH QUESTION

Is industrial air pollution exposure during the first years of life a risk factor for the presence of asthmatic symptoms in children at school age?

METHODS

We assessed the prevalence of asthma symptoms using the ISAAC short form questionnaire for children aged 6-7 years, and measured the FEV1 and PEF in the children of both municipalities (297 children in Călăraşi, i.e. the exposed cohort, and 237 in Roseţi, i.e. the non-exposed cohort).

RESULTS

We found an OR of 7.2 (95% CI: 3.6-14.3) for affirmative answers to at least one of ISAAC questions for children living in Călăraşi compared to the children in Roseţi. The numbers of affirmative answers to all but one of the ISAAC questions were significantly higher in Călăraşi. The main result remained robust after adjusting for a series of co-variables using multiple logistic regression analysis (OR 14.8; 95% CI: 4.8-46.1). There was a strong relation between early life wheezing and asthma symptoms at school age (OR 9.0; 95%CI: 3.4-23.5).

CONCLUSION

Children, who had been living near an iron and steel factory during their early years, are still at increased risk for asthma symptoms at school age.

Quality of routine spirometry tests in Dutch general practices

BACKGROUND

Spirometry is an indispensable tool for diagnosis and monitoring of chronic airways disease in primary care.

AIM

To establish the quality of routine spirometry tests in general practice, and explore associations between test quality and patient characteristics.

DESIGN OF STUDY

Analysis of routine spirometry test records.

SETTING

Fifteen general practices which had a working agreement with a local hospital pulmonary function laboratory for spirometry assessment regarding test quality and interpretation.

METHOD

Spirometry tests were judged by a pulmonary function technician and a chest physician. Proportions of test adequacy were analysed using markers for manoeuvre acceptability and test reproducibility derived from the 1994 American Thoracic Society spirometry guideline. Associations between quality markers and age, sex, and severity of obstruction were examined using logistic regression.

RESULTS

Practices performed a mean of four (standard deviation = 2) spirometry tests per week; 1271 tests from 1091 adult patients were analysed; 96.4% (95% confidence interval [CI] = 95.6 to 97.2) of all tests consisted of ≥3 blows. With 60.6% of tests, forced expiratory time was the marker with the lowest acceptability rate. An overall 38.8% (95% CI = 36.0 to 41.6) of the tests met the acceptability as well as reproducibility criteria. Age, sex, and severity of obstruction were associated with test quality markers.

CONCLUSION

The quality of routine spirometry tests was better than in previous reports from primary care research settings, but there is still substantial room for improvement. Sufficient duration of forced expiratory time is the quality marker with the highest rate of inadequacy. Primary care professionals should be aware of patient characteristics that may diminish the quality of their spirometry tests. Further research is needed to establish to what extent spirometry tests that are inadequate, according to stringent international expert criteria, result in incorrect clinical interpretations in general practice.

Mannitol and exercise challenge tests in asthmatic children

BACKGROUND

Bronchial hyperresponsiveness (BHR), a characteristic feature of asthma, can be assessed through standardized bronchial provocation tests (BPT). Exercise as a BPT is used in diagnosing and monitoring exercise induced bronchoconstriction (EIB). Recently a novel osmotic BPT has been developed, using dry powder mannitol. The aim of this study was to investigate the clinical utility of the mannitol challenge to identify asthmatic children with EIB.

MATERIALS AND METHODS

Thirty-three clinically stable children, aged 9-18 years, with a history of EIB, performed both mannitol and exercise provocation challenges. Data were composed of a cross tabulation comparing the reaction on exercise provocation challenge to mannitol challenge. Correlations between post-exercise fall in FEV1 and response-dose ratio (RDR) and PD1) of mannitol were calculated.

RESULTS

Twenty-five children completed both tests. Pearson's correlation between log-transformed RDR for mannitol and post-exercise fall in FEV1 was r(p) = 0.666 (P < 0.001). There was no significant relationship between the log PD1) of mannitol and post-exercise fall in FEV1. Children on long acting bronchodilator agents (LABA) were significantly (P < 0.05) more likely to have a positive response on the mannitol challenge. Positive and negative predictive values of the mannitol challenge for EIB were 69% and 91%.

CONCLUSION

Mannitol challenge appears to be a suitable alternative for an exercise provocation test to assess EIB in asthmatic children. Given the negative predictive value of 91%, it is especially useful to exclude EIB.

The EPICure study: comparison of pediatric spirometry in community and laboratory settings

RATIONALE

Accuracy of spirometry testing is a prerequisite for its use as an objective outcome measure in large epidemiological studies. We compared spirometry measurements obtained by trained pediatricians in a variety of school settings with those obtained in the laboratory by respiratory physiologists.

METHODS

Following a 3-day training course, three pediatricians carried out spirometry in children born extremely preterm (EP) and age matched controls in schools across the UK and Ireland (The EPICure study). A subgroup had repeated measurements in the laboratory. Spirometric flows and volumes were expressed as Z-scores. Bland-Altman analysis was used to calculate within-subject differences.

RESULTS

Fifty children (40% boys), 37 (74%) of whom were born EP, with a mean age 10.8 years had paired spirometry results (average interval between tests: 20.3 weeks). There was no statistically significant difference between any of the outcome variables: mean (95% CI of difference) in Z-scores [school-laboratory]) being 0.0 (-0.1; 0.1) for FEV(1), 0.1 (-0.1; 0.3) for FVC, -0.1 (-0.3; 0.1) for FEF(25-75), and 0.0 (-0.3; 0.1) for FEV(1)/FVC. Within individuals, the 95% limits of agreement for repeated measures were within +/- 1 Z-score for FEV(1) and FVC, and within +/- 1.5 Z-score for FEF(25-75) and FEV(1)/FVC.

CONCLUSION

With appropriate training, quality control, and support, pediatric spirometry can reliably be performed outside the lung function laboratory.

Reproducibility of spirometry during cystic fibrosis pulmonary exacerbations

OBJECTIVES

To compare the within day variation of spirometry between hospital admission, discharge, and outpatient follow up among children with cystic fibrosis (CF) hospitalized for a pulmonary exacerbation.

HYPOTHESIS

Within day variation of spirometry will be greater at hospital admission than at hospital discharge or outpatient follow up.

METHODS

We performed a retrospective review of spirometry data for all patients with CF >or=6 years old admitted to our pediatric CF center for a pulmonary exacerbation in 2004 or 2005. For patients who had previously performed spirometry successfully, measurements were used from one admission only during 2004-2005 if the spirometry occurred within 3 days of hospital admission, 3 days of discharge, or at a follow up clinic visit when well. We compared the within day coefficients of variation (CV) for FVC, FEV(1), and FEF(25-75) between time points using the Wilcoxon signed rank-test. We also determined the change in spirometry that is likely to be beyond measurement variability during inpatient treatment of a pulmonary exacerbation.

RESULTS

Spirometry data were available from 40 subjects at admission and follow up and 35 at hospital discharge. There was no significant difference in CV at admission, discharge, and follow up for FVC, FEV(1), or FEF(25-75). The mean (SD) CV was 3.1% (2.7) for FVC, 3.2% (2.1) for FEV(1), and 9.7% (7.0) for FEF(25-75) at admission, 2.8% (2.2) for FVC, 3.1% (2.1) for FEV(1), and 8.1% (6.7) for FEF(25-75) at discharge, and 2.7% (1.7) for FVC, 2.8% (2.0) for FEV(1), and 8.4% (7.8) for FEF(25-75) at follow up. These are similar to previous reports of outpatients with CF. The improvement in spirometry that exceeded measurement variability for our cohort was 80 ml for FVC, 70 ml for FEV(1), and 220 ml/sec for FEF(25-75).

CONCLUSIONS

The presence of an acute pulmonary exacerbation in children and adolescents with CF does not substantially contribute to the within day variation in spirometry. Within day variation of spirometry for children with CF during pulmonary exacerbations is similar to previously reported values from clinically stable CF patients.

Acceptability and repeatability of spirometry in children using updated ATS/ERS criteria

Spirometry in pediatrics can be limited by the child's development which is usually related to age. In 2005 the American Thoracic Society (ATS) and European Respiratory Society (ERS) published updated quality control criteria for spirometry. In 2007 the ATS/ERS published specific criteria for spirometry in preschool children 6 years of age and younger. Our primary objective was to determine the influence of age on the ability of children to meet updated spirometry criteria for acceptable and repeatable tests. Our second objective was to determine which criteria are associated with unacceptable tests. Data was prospectively collected over 12 months for children 4-17 years of age performing spirometry for the first time. Unsuccessful tests were analyzed to determine specific criteria not achieved. Three hundred ninety-three studies were collected and 292 (74%) met recently revised ATS/ERS criteria for acceptable and repeatable tests. Acceptable and repeatable test success was not correlated to the gender or race of the children. The percentage of acceptable and repeatable spirometry increased with age rising above 50% by age 6 and reached a plateau with approximately 85% success at age 10. The most common unmet criteria for an unacceptable study among preschool children was glottic closure and non-maximal efforts, while in school-age children was failure to plateau. These data demonstrate most children are able to perform acceptable/repeatable spirometry with their first effort based on revised ATS/ERS criteria.

FEV1 performance among patients with acute asthma: results from a multicenter clinical trial

OBJECTIVE

To determine the ability of patients seen for acute asthma exacerbations in the emergency department (ED) to perform good-quality FEV(1) measurements.

METHODS

Investigators from 20 EDs were trained to perform spirometry testing as part of a clinical trial that included standardized equipment with special software-directed prompts. Spirometry was done on ED arrival and 30 min, 1 h, 2 h, and 4 h later, and during follow-up outpatient visits.

MEASUREMENTS

Study performance criteria differed from American Thoracic Society (ATS) guidelines because of the population acuity and severity of illness as follows: ability to obtain acceptable FEV(1) measures (defined as two or more efforts with forced expiratory times >/= 2 s and time to peak flow < 120 ms or back-extrapolated volume < 5% of the FVC) and reproducibility criteria (two highest acceptable FEV(1) values within 10% of each other).

RESULTS

Of the 620 patients (age range, 12 to 65 years), > 90% met study acceptability criteria on ED arrival and 74% met study reproducibility criteria. Mean initial FEV(1) was 38% of predicted. Spirometry quality improved over time; by 1 h, 90% of patients met study acceptability and reproducibility criteria. Patients with severe airway obstruction (FEV(1) < 25% of predicted) were initially less likely to meet quality goals, but this improved with time. The site was also an independent predictor of quality.

CONCLUSION

When staff are well trained and prompt feedback regarding adequacy of efforts is given, modified ATS performance goals for FEV(1) tests can be met from most acutely ill adolescent and adult asthmatics, even within the first hour of evaluation and treatment for an asthma exacerbation.

Experience using centralized spirometry in the phase 2 randomized, placebo-controlled, double-blind trial of denufosol in patients with mild to moderate cystic fibrosis

BACKGROUND

Centralized spirometry may significantly improve quality of spirometry and reduce variability of this outcome measure in clinical trials in cystic fibrosis (CF).

METHODS

Spirometry was performed during the phase 2 randomized, placebo-controlled, double-blind clinical trial of denufosol in patients with mild to moderate CF using American Thoracic Society guidelines. Uniform spirometers were used with electronic data transmission of all the data to a reading center. Spirometry was evaluated for quality by a central reader based on start of test, cough during the test, and evidence of a plateau.

RESULTS

A total of 1418 spirometry values were assessed in 89 subjects during the trial. In only 5 instances did the central reading center need to give feedback to sites regarding the quality of spirometry. The study site data matched the central reading center's data for all but 78 (6%) spirometry values in 33 patients. Many of these differences were small with only 35 (3%) values differing by more than 50 mL in 26 patients.

CONCLUSION

Spirometry in this clinical trial was of high quality with low rate of significant centralized over-read.

[Respiratory dynamics measurements in children with four to ten years of age]

BACKGROUND

respiratory dynamics measurements are frequently used in the speech-language pathology practice, but few are the scientific data for children.

AIM

to study the respiratory dynamics in children with nasal breathing.

METHOD

the study was performed with a stratified random sample of 106 nasal breathing children, male and female, from schools of the city of Marília-SP, with ages between four and ten years. The following measurements were obtained: vital capacity (VC) in both standing and sitting positions, with and without nasal occlusion; maximum phonation time (MPT) of sustained vowels and consonants and also of speech when counting numbers.

RESULTS

the mean values for VC in the standing position with and without nasal occlusion were of 1515.56ml and 1538.67ml respectively and for the sitting position of 1524ml and 1539.15ml respectively. MPT of vowels in seconds were: /a/ = 8.32, /i/ = 8.61 and /ul = 8.42; of consonants: /s/ = 6.64 and /z/ = 7.65; and when counting numbers: 7.76. It was observed that the mean values of these measurements progressively increased according to age. There was a statistically significant difference (p<0.05) not only for the MPT of vowels but also for the MPT of consonants in older children, i.e. between 4 and 10 year olds, 4 and 9 year olds and 4 and 8 year olds. There was no significant statistical difference for the VC values in consecutive age groups. There was a strong association between VC and the child's physical development.

CONCLUSION

this study presented respiratory dynamics measurements in children that can be used for the spech-language diagnosis and therapy. Other studies should be developed in order to bring additional information on the subject.

Spirometry can be done in family physicians' offices and alters clinical decisions in management of asthma and COPD

BACKGROUND

Spirometry is recommended for diagnosis and management of obstructive lung disease. While many patients with asthma and COPD are cared for by primary care practices, limited data are available on the use and results associated with spirometry in primary care.

OBJECT

To assess the technical adequacy, accuracy of interpretation, and impact of office spirometry.

DESIGN

A before-and-after quasiexperimental design.

SETTING

Three hundred eighty-two patients from 12 family medicine practices across the United States.

PARTICIPANTS

Patients with asthma and COPD, and staff from the 12 practices.

MEASUREMENTS

Technical adequacy of spirometry results, concordance between family physician and pulmonary expert interpretations of spirometry test results, and changes in asthma and COPD management following spirometry testing.

RESULTS

Of the 368 tests completed over the 6 months, 71% were technically adequate for interpretation. Family physician and pulmonary expert interpretations were concordant in 76% of completed tests. Spirometry was followed by changes in management in 48% of subjects with completed tests, including 107 medication changes (>85% concordant with guideline recommendations) and 102 nonpharmacologic changes. Concordance between family physician and expert interpretations of spirometry results was higher in those patients with asthma compared to those with COPD.

DISCUSSION AND CONCLUSIONS

US family physicians can perform and interpret spirometry for asthma and COPD patients at rates comparable to those published in the literature for international primary care studies, and the spirometry results modify care.

Symptom perception and functional morbidity across a 1-year follow-up in pediatric asthma

The purpose of this study was to examine the association between asthma symptom perception measured during a 5-6 week baseline and functional morbidity measured prospectively across a 1-year follow-up. Symptom perception was measured by comparing subjective ratings with peak expiratory flow rate (PEFR) and forced expiratory volume in one second (FEV(1)). We hypothesized that accurate symptom perception (ASP) would be associated with less functional morbidity. Participants consisted of 198 children with asthma ages 7-17 recruited from three sites. The children used a programmable electronic spirometer in the home setting to guess their PEFR prior to exhalation. Each "subjective" guess was classified as being in an ASP, dangerous symptom perception (DSP; underestimation of symptoms), or symptom magnification (SM; overestimation) zone based upon the corresponding measurement of PEFR or FEV(1). An index of functional morbidity was collected by parent report at baseline and across 1-year follow-up. A greater proportion of ASP blows and a lower proportion of DSP blows based on PEFR predicted less functional morbidity reported at baseline, independent of asthma severity and race/ethnicity. A greater proportion of ASP blows (using PEFR and FEV(1)) and a lower proportion of SM blows (using FEV(1)) predicted less functional morbidity across 1-year follow-up. Symptom perception was not associated with emergency department visits for asthma at baseline or across follow-up. In comparison to PEFR, FEV(1) more frequently detected a decline in pulmonary function that children did not report. Symptom perception measured in naturalistic settings was associated with functional morbidity at baseline and prospectively across 1-year follow-up. Support was found for including multiple measures of pulmonary function in the assessment of asthma symptom perception.

On ecological fallacy, assessment errors stemming from misguided variable selection, and the effect of aggregation on the outcome of epidemiological study

In social and environmental sciences, ecological fallacy is an incorrect assumption about an individual based on aggregate data for a group. In the present study, the validity of this assumption was tested using both individual estimates of exposure to air pollution and aggregate data for 1,492 schoolchildren living in the in vicinity of a major coal-fired power station in the Hadera region of Israel. In 1996 and 1999, the children underwent subsequent pulmonary function tests (PFT), and their parents completed a detailed questionnaire on their health status and housing conditions. The association between children's PFT results and their exposure to air pollution was investigated in two phases. During the first phase, PFT averages were compared with average levels of air pollution detected in townships, and small census areas in which the children reside. During the second phase, individual pollution estimates were compared with individual PFT results, and pattern detection techniques (Getis-Ord statistic) were used to investigate the spatial data structure. While different levels of areal data aggregation changed the results only marginally, the choice of indices measuring the children's PFT performance had a significant influence on the outcome of the analysis. As argued, differences between individual-level and group-level effects of exposure (i.e., ecological or cross-level bias) are not necessary outcomes of data aggregation, and that seemingly unexpected results may often stem from a misguided selection of variables chosen to measure health effects. The implications of the results of the analysis for epidemiological studies are discussed, and recommendations for public health policy are formulated.

Evaluation of daily home spirometry for school children with asthma: new insights

Home spirometers are useful for monitoring asthma therapy and for research, but the validity of maneuvers in children is in question. We evaluated the quality of PEF, FEV(1), and FVC data obtained from 67 children with persistent asthma who self-administered spirometry at home using the hand-held ndd EasyOne Frontline Spirometer with full expiratory curve data, electronic measurements of maneuver quality, and on-screen incentives. Half were studied in 2003 in one region, and half in 2004 in another region of Southern California. Subjects were followed at home weekly over 2 months and daily over 10 consecutive days. We retained completed spirometry sessions (9,916) consisting of three of six best maneuvers in the morning, afternoon, and evening. Percent compliance, software assessed repeatability and acceptability modified from American Thoracic Society criteria, and visually assessed quality of maneuvers, were compared across daily and weekly follow-up, study regions, and subject characteristics. Compliance was higher for daily (>90%) than for weekly follow-up (>84%), but not significantly different, and was consistent across subject characteristics. The number with two reproducible and acceptable maneuvers was significantly lower in the first than second region for daily (70 vs. 90%) and weekly follow-up (66 vs. 87%). Of 22,926 software accepted maneuvers, 1,944 (8.5%) were visually rejected (variable effort, cough, glottic closure). Maneuver quality was significantly lower for subjects age 9-12 versus 13-18 years, for subjects not taking anti-inflammatory medications, and for subjects with <80% predicted FEV(1). Longitudinal data collection is possible in children with asthma by employing repeated home training and follow-up, and using spirometers with built in quality assurance and incentive software. Region, age, and multiple indicators of persistent asthma, predict ability to perform reliable and accurate lung function maneuvers.

Spirometry in 3-5-year-old children with asthma

Spirometry with incentive games was applied to 207 2-5-year-old preschool children (PSC) with asthma in order to refine the quality-control criteria proposed by Aurora et al. (Am J Respir Crit Care Med 2004;169:1152-159). The data set in our study was much larger compared to that in Aurora et al. (Am J Respir Crit Care Med 2004;169:1152-159), where 42 children with cystic fibrosis and 37 healthy control were studied. At least two acceptable maneuvers were obtained in 178 (86%) children. Data were focused on 3-5-year-old children (n = 171). The proportion of children achieving a larger number of thresholds for each quality-control criterion (backward-extrapolated volume (Vbe), Vbe in percent of forced vital capacity (FVC, Vbe/FVC), time-to-peak expiratory flow (time-to-PEF), and difference (Delta) between the two FVCs (DeltaFVC), forced expiratory volume in 1 sec (DeltaFEV(1)), and forced expiratory volume in 0.5 sec (DeltaFEV(0.5)) from the two "best" curves) was calculated, and cumulative plots were obtained. The optimal threshold was determined for all ages by derivative function of rate of success-threshold curves, close to the inflexion point. The following thresholds were defined for acceptability: Vbe <or=75 ml and <or=10% of FVC, time-to-PEF <120 msec, and repeatability: DeltaFEV(1) and DeltaFEV(0.5) <or=110 ml and <or=10% of best effort, and DeltaFVC <or=100 ml and <or=12.5%. These were obtained in 85%, 93%, 94%, 90%, and 89% of children, respectively. For practical reasons, we suggest choosing the same threshold for all repeatability criteria, i.e., DeltaFVC, DeltaFEV(1), and DeltaFEV(0.5) <or=110 ml and <or=10%. In conclusion, a majority of PSC with asthma can perform at least two acceptable maneuvers. Acceptability and repeatability criteria defined in a larger data set can be applied to preschool children. Spirometry could therefore be used to assess respiratory function in preschool children with asthma.

Office spirometry in primary care pediatrics: a pilot study

OBJECTIVE

The aim of this study was to investigate the validity of office spirometry in primary care pediatric practices.

METHODS

Ten primary care pediatricians undertook a spirometry training program that was led by 2 pediatric pulmonologists from the Pediatric Department of the University of Padova. After the pediatricians' training, children with asthma or persistent cough underwent a spirometric test in the pediatrician's office and at a pulmonary function (PF) laboratory, in the same day in random order. Both spirometric tests were performed with a portable turbine flow sensor spirometer. We assessed the quality of the spirometric tests and compared a range of PF parameters obtained in the pediatricians' offices and in the PF laboratory according to the Bland and Altman method.

RESULTS

A total of 109 children (mean age: 10.4 years; range: 6-15) were included in the study. Eighty-five (78%) of the spirometric tests that were performed in the pediatricians' offices met all of the acceptability and reproducibility criteria. The 24 unacceptable test results were attributable largely to a slow start and failure to satisfy end-of-test criteria. Only the 85 acceptable spirometric tests were considered for analysis. The agreement between the spirometric tests that were performed in the pediatrician's office and in the PF laboratory was good for the key parameters (forced vital capacity, forced expiratory volume in 1 second, and forced expiratory flow between 25% and 75%). The repeatability coefficient was 0.26 L for forced expiratory volume in 1 second (83 of 85 values fall within this range), 0.30 L for forced vital capacity (81 values fall within this range), and 0.58 L/s for forced expiratory flow between 25% and 75% (82 values fall within this range). In 79% of cases, the primary care pediatricians interpreted the spirometric tests correctly.

CONCLUSIONS

It seems justifiable to perform spirometry in pediatric primary care, but an integrated approach involving both the primary care pediatrician and certified pediatric respiratory medicine centers is recommended because effective training and quality assurance are vital prerequisites for successful spirometry.

Increasing Peak Expiratory Flow Time in Amyotrophic Lateral Sclerosis

BACKGROUND

Serial measurements of pulmonary function to indicate decreasing respiratory muscle strength in patients with amyotrophic lateral sclerosis (ALS) is well documented. Quantitative outcome measures include declining FVC, FEV1, maximal inspired pressure, maximal expired pressure, and maximal voluntary ventilation. Increasing peak expiratory flow time (PEFT) may represent a further sensitive measure of declining respiratory muscle strength in ALS.

METHODS

Fifty-five patients with ALS performed flow-volume loops serially after presentation. The percentage change from baseline values for FVC, peak expiratory flow (PEFR), and PEFT were compared using Spearman correlation coefficients. The prolongation of PEFT with serial tests was analyzed using a Kruskal-Wallis with a Dunn multiple comparison test. Bulbar-onset and limb-onset PEFT was compared using the Mann-Whitney test.

RESULTS

PEFT was significantly increased from baseline values at all follow-up tests. However, PEFTs measured at the third, fourth, fifth, and sixth visits, although higher, were not significantly different. Significant negative correlations existed between the increase in PEFT and the decrease in PEFR and FVC. Significant positive correlations existed between the increase in PEFT and days from diagnosis and the decrease in PEFR and decrease in FVC.

CONCLUSION

PEFT increases significantly and linearly with time in patients with ALS and may begin to plateau with bulbar symptoms. PEFT increases at a faster rate than the rate of decline in both FVC and PEFR. PEFT is a quantitative measure of decreasing pulmonary function in ALS that is easily measured.

Respiratory function testing: the impact of respiratory scientists on the training and support of primary health care providers

OBJECTIVE

In rural Australia access to doctors is limited, access to respiratory physicians even more so and these are the traditional sources of lung function testing. The aim of this study was to assess the feasibility of training and supporting existing rural primary healthcare providers in lung function testing as a screening and monitoring mechanism due to the shortage of healthcare professionals capable of providing such a service.

METHODOLOGY

As pharmacists are readily accessible healthcare professionals, they were trained in spirometry measurement and supported with ongoing quality assurance by respiratory scientists. Spirometers were provided to the pharmacists. People purchasing respiratory medications or responding to advertising about the service were tested after giving informed consent. Spirometic assessments were assessed for accuracy and reproducibility. Participants' spirometry results were reviewed and those with abnormal test results were referred to their doctor.

RESULTS

Pharmacists were able to competently develop the skills necessary for providing spirometry measurement as a screening and monitoring technique. The level of competence exceeded that reported in previously published studies. Pharmacists were able to successfully identify spirometry results within the normal range.

CONCLUSIONS

Training and supporting accessible healthcare professionals to provide lung function testing increases access in areas of need and has implications for respiratory morbidity and mortality in such settings.