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

A comparison of peak cough flow and peak expiratory flow in children with neuromuscular disorders

Spirometry and peak cough flow testing (PCF) are commonly used in the respiratory assessment of children with a neuromuscular disorder (NMD). Testing uses two different machines, increases laboratory time, costs and resource utilisation. No studies have assessed the correlation between peak expiratory flow (PEF) obtained from spirometry and PCF in children with NMD using one device. An audit of children with a NMD managed at the Children's Hospital at Westmead in 2022-2024 aged < 20 years who performed spirometry and PCF testing on the same device (Vyaire Body BoxTM, Ultrasonic flow meter-based, or Vyaire PneumotachographTM, Pneumotach flow meter-based; Germany) was conducted to assess the correlation between PCF and PEF. Fifty-one sets of testing were identified, and 40 subjects (9F) had reproducible testing and were included. Median (range) age was 14.95 (7.20-19.00) years. Median PEF (L/min) was 4.05 (1.22-10.26) and median PCF (L/min) was 4.29 (1.69-10.82). PEF and PCF had a strong Pearson's correlation coefficient, (R = 0.97, p = 0.03). The coefficient of determination was 0.93. If laboratory resources permit, spirometry should be the test of choice for children with NMD. On average, spirometry required multiple practices to achieve reproducibility to meet ATS/ERS standards. PCF testing can be utilised for children where performing technically acceptable spirometry is not possible.

Detection of Bronchiolitis Obliterans Syndrome after Pediatric Hematopoietic Stem Cell Transplantation: An Official American Thoracic Society Clinical Practice Guideline

Background: Many children undergo allogeneic hematopoietic stem cell transplantation (HSCT) for the treatment of malignant and nonmalignant conditions. Unfortunately, pulmonary complications occur frequently post-HSCT, with bronchiolitis obliterans syndrome (BOS) being the most common noninfectious pulmonary complication. Current international guidelines contain conflicting recommendations regarding post-HSCT surveillance for BOS, and a recent NIH workshop highlighted the need for a standardized approach to post-HSCT monitoring. As such, this guideline provides an evidence-based approach to detection of post-HSCT BOS in children. Methods: A multinational, multidisciplinary panel of experts identified six questions regarding surveillance for, and evaluation of, post-HSCT BOS in children. A systematic review of the literature was undertaken to answer each question. The Grading of Recommendations, Assessment, Development, and Evaluation approach was used to rate the quality of evidence and the strength of recommendations. Results: The panel members considered the strength of each recommendation and evaluated the benefits and risks of applying the intervention. In formulating the recommendations, the panel considered patient and caregiver values, the cost of care, and feasibility. Recommendations addressing the role of screening pulmonary function testing and diagnostic tests in children with suspected post-HSCT BOS were made. Following a Delphi process, new diagnostic criteria for pediatric post-HSCT BOS were also proposed. Conclusions: This document provides an evidence-based approach to the detection of post-HSCT BOS in children while also highlighting considerations for the implementation of each recommendation. Further, the document describes important areas for future research.

Telemedicine and home spirometry in cystic fibrosis: A prospective multicenter study

OBJECTIVES

Telehealth and home spirometry feasibility for children has been established, but their impact on cystic fibrosis (CF) disease progression remains unassessed. We aimed to evaluate the effects of telehealth and home spirometry on CF disease progression and care.

METHODS

Children with CF aged 5-17 years from all Swedish CF centers were provided with home spirometers. A minimum of two in-person visits were replaced with telemedicine visits and participants were instructed to conduct home spirometry before visits. Linear mixed-effects models were used to compare annual CF disease trajectories during the intervention period and prepandemic period (1 January 2019 to 28 February 2020). Participants and caregivers completed study questionnaires.

RESULTS

A total of 59 individuals completed the study over a mean (SD) period of 6.8 (1.4) months, made 3.1 (1.0) physical visits and 2.2 (0.6) telehealth visits per patient year during the study period. The mean difference (95% CI) between the intervention and prepandemic period progression rate for FEV1%, lung clearance index and BMI were -0.4 (-1.3 to 0.5, p = 0.39), 0.11 (-0.07 to 0.28, p = 0.25) and -0.02 (-0.13 to 0.08, p = 0.70), respectively. There were no major shifts in the incidence of airway pathogens, sputum cultures, or antibiotics use between the periods (p > 0.05). The intervention did not increase stress. Almost all participants and caregivers expressed a desire to continue with home spirometry and telemedicine.

CONCLUSION

Combining telehealth and physical visits with access to home spirometry demonstrated comparable effectiveness as exclusively in-person care with enhanced flexibility and personalization of CF care.

Flexible bronchoscopy in pediatric lung transplantation

Pediatric lung transplantation represents a treatment option for children with advanced lung disease or pulmonary vascular disorders who are deemed an appropriate candidate. Pediatric flexible bronchoscopy is an important and evolving field that is highly relevant in the pediatric lung transplant population. It is thus important to advance our knowledge to better understand how care for children after lung transplant can be maximally optimized using pediatric bronchoscopy. Our goals are to continually improve procedural skills when performing bronchoscopy and to decrease the complication rate while acquiring adequate samples for diagnostic evaluation. Attainment of these goals is critical since allograft assessment by bronchoscopic biopsy is required for histological diagnosis of acute cellular rejection and is an important contributor to establishing chronic lung allograft dysfunction, a common complication after lung transplant. Flexible bronchoscopy with bronchoalveolar lavage and transbronchial lung biopsy plays a key role in lung transplant graft assessment. In this article, we discuss the application of bronchoscopy in pediatric lung transplant evaluation including historical approaches, our experience, and future directions not only in bronchoscopy but also in the evolving pediatric lung transplantation field. Pediatric flexible bronchoscopy has become a vital modality for diagnosing lung transplant complications in children as well as assessing therapeutic responses. Herein, we review the value of flexible bronchoscopy in the management of children after lung transplant and discuss the application of novel techniques to improve care for this complex pediatric patient population and we provide a brief update about new diagnostic techniques applied in the growing lung transplantation field.

(F)utility of preoperative pulmonary function testing in pectus excavatum to assess severity

PURPOSE

The utility of pulmonary function testing (PFT) in pectus excavatum (PE) has been subject to debate. Although some evidence shows improvement from preoperative to postoperative values, the clinical significance is uncertain. A high failure-to-completion rate for operative PFT (48%) was identified in our large institutional cohort. With such a high non-completion rate, we questioned the overall utility of PFT in the preoperative assessment of PE and sought to evaluate if other measures of PE severity or cardiopulmonary function could explain this finding.

METHODS

Demographics, clinical findings, and results from cardiac MRI, PFT (spirometry and plethysmography), and cardiopulmonary exercise tests (CPET) were reviewed in 270 patients with PE evaluated preoperatively between 2015 and 2018. Regression modeling was used to measure associations between PFT completion and cardiopulmonary function.

RESULTS

There were no differences in demographics, symptoms, connective tissue disorders, or multiple indices of pectus severity and cardiac deformation in PFT completers versus non-completers. While regression analysis revealed higher RVEF, LVEF, and LVEF-Z scores, lower RV-ESV/BSA, LV-ESV/BSA, and LV-ESV/BSA-Z scores, and abnormal breathing reserve in PFT completers vs. non-completers, these findings were not consistent across continuous and binary analyses.

CONCLUSIONS

We found that PFT completers were not significantly different from non-completers in most structural and functional measures of pectus deformity and cardiopulmonary function. Inability to complete PFT is not an indicator of pectus severity.

Mother's smoking habits affects IL10 methylation but not asthma in Ecuadorian children

There is no evidence evaluating the IL10 epigenetic upregulation among mestizo children in a high-altitude Andean city in Latin America.

OBJECTIVE

To identify polymorphisms and methylation profiles in the IL10 gene associated with asthma in children aged 5 to 11.

METHODS

A case-control study was conducted with asthmatic and non-asthmatic children aged 5 to 11 years in Cuenca-Ecuador. Data on allergic diseases and risk factors were collected through a questionnaire for parents. Atopy was measured by skin prick test (SPT) to relevant aeroallergens. Three IL10 single nucleotide polymorphisms were evaluated in all participants, and methylation analysis was performed in 54 participants. Association between risk factors, allergic diseases and genetic factors were estimated using multivariate logistic regression.

RESULTS

The results of polymorphisms showed no differences between cases and controls when comparing the SNPs rs3024495, rs3024496, rs1800896 allelic and genotypic frequencies. In the methylation analysis, no differences in the IL10 methylation profile were found between cases and controls; however, the multivariate analysis showed an association between the mother's smoking habits and the IL10 methylation profile.

CONCLUSION

Smoking habit could be essential as an environmental exposure factor in regulating gene expression in children with asthma.

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.

Diagnosis and Management of the Systemic Juvenile Idiopathic Arthritis Patient with Emerging Lung Disease

Chronic lung disease in children with systemic juvenile idiopathic arthritis (SJIA-LD) is an emerging and potentially life-threatening disease complication. Despite recent descriptions of its clinical spectrum, preliminary immunologic characterization, and proposed hypotheses regaarding etiology, optimal approaches to diagnosis and management remain unclear. Here, we review the current clinical understanding of SJIA-LD, including the potential role of biologic therapy in disease pathogenesis, as well as the possibility of drug reactions with eosinophilia and systemic symptoms (DRESS). We discuss approaches to evaluation of children with suspected SJIA-LD, including a proposed algorithm to risk-stratify all SJIA patients for screening to detect LD early. We review potential pharmacologic and non-pharmacologic treatment approaches that have been reported for SJIA-LD or utilized in interstitial lung diseases associated with other rheumatic diseases. This includes lymphocyte-targeting therapies, JAK inhibitors, and emerging therapies against IL-18 and IFNγ. Finally, we consider urgent unmet needs in this area including in basic discovery of disease mechanisms and clinical research to improve disease detection and patient outcomes.

Clinic vs Home Spirometry for Monitoring Lung Function in Patients With Asthma

BACKGROUND

Studies examining agreement between home and clinic spirometry in patients with asthma are limited, with conflicting results. Understanding the strengths and limitations of telehealth and home spirometry is particularly important considering the SARS-CoV-2 pandemic.

RESEARCH QUESTION

How well do home and clinic measurements of trough FEV1 agree in patients with uncontrolled asthma?

STUDY DESIGN AND METHODS

This post hoc analysis used trough FEV1 data from the randomized double-anonymized parallel-group phase 3A CAPTAIN (205715; NCT02924688) and phase 2B 205832 (NCT03012061) trials in patients with uncontrolled asthma. CAPTAIN evaluated the impact of adding umeclidinium to fluticasone furoate/vilanterol via a single inhaler; the 205832 trial investigated adding umeclidinium to fluticasone furoate vs placebo. Trough FEV1 measurements were collected via home spirometry and supervised in-person spirometry in the research clinic. To compare home and clinic spirometry, we examined the time-course analyses of home and clinic trough FEV1, and generated post hoc Bland-Altman plots to assess agreement between home and clinic spirometry.

RESULTS

Data from 2,436 patients (CAPTAIN trial) and 421 patients (205832 trial) were analyzed. Treatment-related improvements in FEV1 were observed in both trials, using home and clinic spirometry. Improvements measured by home spirometry were of lower magnitude and less consistent than clinic measurements. Bland-Altman plots suggested poor agreement between home and clinic trough FEV1 at baseline and week 24.

INTERPRETATION

This post hoc comparison of home and clinic spirometry is the largest conducted in asthma. Results showed that home spirometry was less consistent than and lacked agreement with clinic spirometry, suggesting that unsupervised home readings are not interchangeable with clinic measurements. However, these findings may only be applicable to home spirometry using the specific device and coaching methods employed in these studies. Postpandemic, further research to optimize home spirometry use is needed.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov; Nos.: NCT03012061 and NCT02924688; URL: www.

CLINICALTRIALS

gov.

Small airways in asthma: Pathophysiology, identification and management

Background

The aim of this review is to summarize the current evidence regarding small airway disease in asthma, focusing on recent advances in small airway pathophysiology, assessment and therapeutic implications.

Methods

A search in Medline was performed, using the keywords "small airways", "asthma", "oscillometry", "nitrogen washout" and "imaging". Our review was based on studies from adult asthmatic patients, although evidence from pediatric populations is also discussed.

Results

In asthma, inflammation in small airways, increased mucus production and airway wall remodelling are the main pathogenetic mechanisms of small airway disease. Small airway dysfunction is a key component of asthma pathophysiology, leading to increased small airway resistance and airway closure, with subsequent ventilation inhomogeneities, hyperresponsiveness and airflow limitation. Classic tests of lung function, such as spirometry and body plethysmography are insensitive to detect small airway disease, providing only indirect measurements. As discussed in our review, both functional and imaging techniques that are more specific for small airways, such as oscillometry and the multiple breath nitrogen washout have delineated the role of small airways in asthma. Small airways disease is prevalent across all asthma disease stages and especially in severe disease, correlating with important clinical outcomes, such as asthma control and exacerbation frequency. Moreover, markers of small airways dysfunction have been used to guide asthma treatment and monitor response to therapy.

Conclusions

Assessment of small airway disease provides unique information for asthma diagnosis and monitoring, with potential therapeutic implications.

Adherence, reliability, and variability of home spirometry telemonitoring in cystic fibrosis

Introduction

Forced spirometry is the gold standard to assess lung function, but its accessibility may be limited. By contrast, home spirometry telemonitoring allows a multi-weekly lung function follow-up but its real-life adherence, reliability, and variability according to age have been poorly studied in patients with CF (PwCF). We aimed to compare real-life adherence, reliability and variability of home spirometry between children, teenagers and adults with CF.

Methods

This real-life observational study included PwCF followed for six months in whom lung function (i.e, forced expiratory volume maximum in 1 s (FEV1), forced vital capacity (FVC), forced mid-expiratory flow (FEF) and FEV1/FVC ratio) was monitored by both conventional and home spirometry between July 2015 and December 2021. The adherence, reliability and variability of home spirometry was assessed in all PwCF and compared between children (<12years old), teenagers (12-18 years old) and adults.

Results

174 PwCF were included (74 children, 43 teenagers and 57 adults). Home spirometry was used at least one time per week by 64.1 ± 4.9% PwCF, more frequently in children and teenagers than in adults (79.4 ± 2.9%, 69.2 ± 5.5% and 40.4 ± 11.5% respectively). The reliability to conventional lung function testing was good for all assessed parameters (e.g., FEV1: r = 0.91, p < 0.01) and the variability over the 6 months of observation was low (FEV1 coefficient of variation = 11.5%). For each parameter, reliability was better, and the variability was lower in adults than in teenagers than in children.

Conclusion

Home spirometry telemonitoring appears to be a reliable tool for multi-weekly lung function follow-up of PwCF.

Associations between sleep, obesity, and asthma in urban minority children

STUDY OBJECTIVES

Although obesity, asthma, and sleep-disordered breathing are interrelated, there is limited understanding of the independent contributions of body-mass index and pulmonary function on polysomnography in children with asthma.

METHODS

We conducted a retrospective chart review on 448 7- to 18-year-old children with asthma who had undergone polysomnography testing between 1/2007-12/2011 to elucidate the association between spirometry variables, body-mass index, and polysomnography parameters, adjusting for asthma and antiallergic medications.

RESULTS

Obese children had poorer sleep architecture and more severe gas exchange abnormalities compared to healthy weight children. Multivariate analysis revealed an independent association of body-mass index with sleep efficiency, with more light and less deep sleep in both obese and healthy-weight children, and with baseline oxygen saturation and oxygen nadir in obese children. In obese children, forced vital capacity was independently associated with less deep sleep (time in N3 sleep) as well as with oxygen nadir, while among healthy-weight children, forced expiratory volume directly correlated but forced vital capacity inversely correlated with deep sleep. In obese children, inhaled corticosteroid was associated with baseline oxygen saturation, and montelukast was associated with lower end-tidal carbon dioxide. In healthy-weight children, inhaled corticosteroid was associated with arousal awakening index, and montelukast was associated with light sleep. Antiallergic medications were not independently associated with polysomnography parameters.

CONCLUSIONS

Pulmonary function, body-mass index, and asthma medications have independent and differing influences on sleep architecture and gas exchange polysomnography parameters in obese and healthy-weight children with asthma. Asthma medications are associated with improved gas exchange in obese children and improved sleep architecture in healthy-weight children with asthma.

CITATION

Conrad LA, Nandalike K, Rani S, Rastogi D. Associations between sleep, obesity, and asthma in urban minority children. J Clin Sleep Med. 2022;18(10):2377-2385.

Geographical Differences and Temporal Improvements in Forced Expiratory Volume in 1 Second of Preterm-Born Children: A Systematic Review and Meta-analysis

Importance

Although preterm birth is associated with later deficits in lung function, there is a paucity of information on geographical differences and whether improvements occur over time, especially after surfactant was introduced.

Objective

To determine deficits in percentage predicted forced expiratory volume in 1 second (%FEV1) in preterm-born study participants, including those with bronchopulmonary dysplasia (BPD) in infancy, when compared with term-born control groups.

Data Sources

Eight databases searched up to December 2021.

Study Selection

Studies reporting spirometry for preterm-born participants with or without a term-born control group were identified.

Data Extraction and Synthesis

Data were extracted and quality assessed by 1 reviewer and checked by another. Data were pooled using random-effects models and analyzed using Review Manager and the R metafor package.

Main Outcomes and Measures

Deficits in %FEV1 between preterm-born and term groups. Associations between deficits in %FEV1 and year of birth, age, introduction of surfactant therapy, and geographical region of birth and residence were also assessed.

Results

From 16 856 titles, 685 full articles were screened: 86 with and without term-born control groups were included. Fifty studies with term controls were combined with the 36 studies from our previous systematic review, including 7094 preterm-born and 17 700 term-born participants. Of these studies, 45 included preterm-born children without BPD, 29 reported on BPD28 (supplemental oxygen dependency at 28 days), 26 reported on BPD36 (supplemental oxygen dependency at 36 weeks' postmenstrual age), and 86 included preterm-born participants. Compared with the term-born group, the group of all preterm-born participants (all preterm) had deficits of %FEV1 of -9.2%; those without BPD had deficits of -5.8%, and those with BPD had deficits of approximately -16% regardless of whether they had BPD28 or BPD36. As year of birth increased, there was a statistically significant narrowing of the difference in mean %FEV1 between the preterm- and term-born groups for the all preterm group and the 3 BPD groups but not for the preterm-born group without BPD. For the all BPD group, when compared with Scandinavia, North America and western Europe had deficits of -5.5% (95% CI, -10.7 to -0.3; P = .04) and -4.1% (95% CI, -8.8 to 0.5; P = .08), respectively.

Conclusions and Relevance

Values for the measure %FEV1 were reduced in preterm-born survivors. There were improvements in %FEV1 over recent years, but geographical region had an association with later %FEV1 for the BPD groups.

Can the response to a single dose of beclomethasone dipropionate predict the outcome of long-term treatment in childhood exercise-induced bronchoconstriction?

BACKGROUND

Exercise-induced bronchoconstriction (EIB) is a frequent and highly specific symptom of childhood asthma. Inhaled corticosteroids (ICS) are the mainstay of controller therapy for EIB and asthma; however, a proportion of asthmatic children and adolescents is less responsive to ICS. We hypothesized that a single dose response to ICS could function as a predictor for individual long-term efficacy of ICS.

OBJECTIVE

To assess the predictive value of the bronchoprotective effect of a single-dose beclomethasone dipropionate (BDP) against EIB for the bronchoprotective effect of 4 weeks of treatment, using an exercise challenge test (ECT).

METHODS

Thirty-two steroid-naïve children and adolescents aged 6 to 18 years with EIB were included in this prospective cohort study. They performed an ECT at baseline, after a single-dose BDP (200µg) and after 4 weeks of BDP treatment (100 µg twice daily) to assess EIB severity.

RESULTS

The response to a single-dose BDP on exercise-induced fall in FEV1 showed a significant correlation with the response on exercise-induced fall in FEV1 after 4 weeks of BDP treatment (r = .38, p = .004). A reduction in post-exercise fall in FEV1 of more than 8% after a single-dose BDP could predict BDP efficacy against EIB after 4 weeks of treatment with a positive predictive value of 100% (CI: 86.1-100%) and a negative predictive value of 29.4% (CI: 11.7%-53.7%).

CONCLUSION

We found that the individual response to a single-dose BDP against EIB has a predictive value for the efficacy of long-term treatment with BDP. This could support clinicians in providing personalized management of EIB in childhood asthma.

Changes in ventilation distribution in children with neuromuscular disease using the insufflator/exsufflator technique: an observational study

Patients with neuromuscular disease often suffer from weak and ineffective cough resulting in mucus retention and increased risk for chest infections. Different airway clearance techniques have been proposed, one of them being the insufflator/exsufflator technique. So far, the immediate physiological effects of the insufflator/exsufflator technique on ventilation distribution and lung volumes are not known. We aimed to describe the immediate effects of the insufflator/exsufflator technique on different lung volumes, forced flows and ventilation distribution. Eight subjects (age 5.8–15.2 years) performed lung function tests including spirometry, multiple breath washout and electrical impedance tomography before and after a regular a chest physiotherapy session with an insufflator/exsufflator device. Forced lung volumes and flows as well as parameters of ventilation distribution derived from multiple breath washout and electrical impedance tomography were compared to assess the short-term effect of the therapy. In this small group of stable paediatric subjects with neuromuscular disease we could not demonstrate any short-term effects of insufflation/exsufflation manoeuvres on lung volumes, expiratory flows and ventilation distribution. With the currently used protocol of the insufflation/exsufflation manoeuvre, we cannot demonstrate any immediate changes in lung function.

Community-based asthma assessment in young children: adaptations for a multicentre longitudinal study in South Asia

Background:

Systematic assessment of childhood asthma is challenging in low- and middle-income country (LMIC) settings due to the lack of standardised and validated methodologies. We describe the contextual challenges and adaptation strategies in the implementation of a community-based asthma assessment in four resource-constrained settings in Bangladesh, India, and Pakistan.

Method:

We followed a group of children of age 6–8 years for 12 months to record their respiratory health outcomes. The study participants were enrolled at four study sites of the ‘Aetiology of Neonatal Infection in South Asia (ANISA)’ study. We standardised the research methods for the sites, trained field staff for uniform data collection and provided a ‘Child Card’ to the caregiver to record the illness history of the participants. We visited the children on three different occasions to collect data on respiratory-related illnesses. The lung function of the children was assessed in the outreach clinics using portable spirometers before and after 6-minute exercise, and capillary blood was examined under light microscopes to determine eosinophil levels.

Results:

We enrolled 1512 children, 95.5% (1476/1512) of them completed the follow-up, and 81.5% (1232/1512) participants attended the lung function assessment tests. Pre- and post-exercise spirometry was performed successfully in 88.6% (1091/1232) and 85.7% (1056/1232) of children who attempted these tests. Limited access to health care services, shortage of skilled human resources, and cultural diversity were the main challenges in adopting uniform procedures across all sites. Designing the study implementation plan based on the local contexts and providing extensive training of the healthcare workers helped us to overcome these challenges.

Conclusion:

This study can be seen as a large-scale feasibility assessment of applying spirometry and exercise challenge tests in community settings of LMICs and provides confidence to build capacity to evaluate children’s respiratory outcomes in future translational research studies.

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.

National Institutes of Health Consensus Development Project on Criteria for Clinical Trials in Chronic Graft-versus-Host Disease: IV. The 2020 Highly morbid forms report

Chronic graft-versus-host disease (GVHD) can be associated with significant morbidity, in part because of nonreversible fibrosis, which impacts physical functioning (eye, skin, lung manifestations) and mortality (lung, gastrointestinal manifestations). Progress in preventing severe morbidity and mortality associated with chronic GVHD is limited by a complex and incompletely understood disease biology and a lack of prognostic biomarkers. Likewise, treatment advances for highly morbid manifestations remain hindered by the absence of effective organ-specific approaches targeting "irreversible" fibrotic sequelae and difficulties in conducting clinical trials in a heterogeneous disease with small patient numbers. The purpose of this document is to identify current gaps, to outline a roadmap of research goals for highly morbid forms of chronic GVHD including advanced skin sclerosis, fasciitis, lung, ocular and gastrointestinal involvement, and to propose strategies for effective trial design. The working group made the following recommendations: (1) Phenotype chronic GVHD clinically and biologically in future cohorts, to describe the incidence, prognostic factors, mechanisms of organ damage, and clinical evolution of highly morbid conditions including long-term effects in children; (2) Conduct longitudinal multicenter studies with common definitions and research sample collections; (3) Develop new approaches for early identification and treatment of highly morbid forms of chronic GVHD, especially biologically targeted treatments, with a special focus on fibrotic changes; and (4) Establish primary endpoints for clinical trials addressing each highly morbid manifestation in relationship to the time point of intervention (early versus late). Alternative endpoints, such as lack of progression and improvement in physical functioning or quality of life, may be suitable for clinical trials in patients with highly morbid manifestations. Finally, new approaches for objective response assessment and exploration of novel trial designs for small populations are required.

129Xe MRI as a measure of clinical disease severity for pediatric asthma

BACKGROUND

Measurement of regional lung ventilation with hyperpolarized ¹²⁹Xe magnetic resonance imaging (¹²⁹Xe MRI) in pediatric asthma is poised to advance our understanding of disease mechanisms and pathophysiology in a disorder with diverse clinical phenotypes. ¹²⁹Xe MRI has not been investigated in a pediatric asthma cohort.

OBJECTIVE

We hypothesized that ¹²⁹Xe MRI is feasible and can demonstrate ventilation defects that relate to and predict clinical severity in a pediatric asthma cohort.

METHODS

Thirty-seven children (13 with severe asthma, 8 with mild/moderate asthma, 16 age-matched healthy controls) aged 6 to 17 years old were imaged with ¹²⁹Xe MRI. Ventilation defect percentage (VDP) and image reader score were calculated and compared with clinical measures at baseline and at follow-up.

RESULTS

Children with asthma had higher VDP (P = .002) and number of defects per image slice (defects/slice) (P = .0001) than children without asthma. Children with clinically severe asthma had significantly higher VDP and number of defects/slice than healthy controls. Children with asthma who had a higher number of defects/slice had a higher rate of health care utilization (r = 0.48; P = .03) and oral corticosteroid use (r = 0.43; P = .05) at baseline. Receiver-operating characteristic analysis demonstrated that the VDP and number of defects/slice were predictive of increased health care utilization, asthma, and severe asthma. VDP correlated with FEV₁ (r = -0.35; P = .04) and FEV₁/forced vital capacity ratio (r = -0.41; P = .01).

CONCLUSIONS

¹²⁹Xe MRI correlates with asthma severity, health care utilization, and oral corticosteroid use. Because delineation of clinical severity is often difficult in children, ¹²⁹Xe MRI may be an important biomarker for severity, with potential to identify children at higher risk for exacerbations and improve outcomes.

Quantitative inspiratory-expiratory chest CT to evaluate pulmonary involvement in pediatric hematopoietic stem-cell transplantation patients

Pulmonary complications following allogeneic hematopoietic stem-cell transplantation (HSCT) are a significant source of morbidity and complications may arise from a myriad of infectious and noninfectious sources. These complications may occur soon or many months post-transplantation and can have a broad range of outcomes. Surveillance for pulmonary involvement in the pediatric HSCT population can be challenging due to poor compliance with clinical pulmonary function testing, primarily spirometry, and there may be a role for clinical imaging to provide an additional means of monitoring, particularly in the era of clinical low-dose computed tomography (CT) protocols. In this single-site, retrospective study, a review of our institution's radiological and HSCT databases was conducted to assess the utility of a quantitative CT algorithm to describe ventilation abnormalities on high-resolution chest CT scans of pediatric HSCT patients. Thirteen non-contrast enhanced chest CT examinations acquired both in inspiration and expiration, from 12 deceased HSCT patients (median age at HSCT 10.4 years, median days of CT 162) were selected for the analysis. Also, seven age-matched healthy controls (median age 15.5) with non-contrast-enhanced inspiration-expiration chest CT were selected for comparison. We report that, compared to healthy age-matched controls, HSCT patients had larger percentages of poorly ventilated (median, 13.5% vs. 2.3%, p < .001) and air trapped (median 12.3% vs. 0%, p < .001) regions of lung tissue, suggesting its utility as a potential screening tool. Furthermore, there was wide variation within individual HSCT patients, supporting the use of multivolume CT and quantitative analysis to describe and phenotype post-transplantation lung involvement.

The Need for Testing-The Exercise Challenge Test to Disentangle Causes of Childhood Exertional Dyspnea

Exertional dyspnea is a common symptom in childhood which can induce avoidance of physical activity, aggravating the original symptom. Common causes of exertional dyspnea are exercise induced bronchoconstriction (EIB), dysfunctional breathing, physical deconditioning and the sensation of dyspnea when reaching the physiological limit. These causes frequently coexist, trigger one another and have overlapping symptoms, which can impede diagnoses and treatment. In the majority of children with exertional dyspnea, EIB is not the cause of symptoms, and in asthmatic children it is often not the only cause. An exercise challenge test (ECT) is a highly specific tool to diagnose EIB and asthma in children. Sensitivity can be increased by simulating real-life environmental circumstances where symptoms occur, such as environmental factors and exercise modality. An ECT reflects daily life symptoms and impairment, and can in an enjoyable way disentangle common causes of exertional dyspnea.

Non-invasive forced oscillometry to quantify respiratory mechanics in term neonates

BACKGROUND

To determine normative data by forced oscillation technique (FOT) in non-sedated normal term neonates and test the hypothesis that infants with transient tachypnea of the newborn (TTN) have higher resistance (R) and lower reactance (X) on day 1.

METHODS

Healthy term infants (n = 138) and infants with TTN (n = 17) were evaluated on postnatal days 1 through 3 (NCT03346343). FOT was measured with a mask using a TremoFlo C-100 Airwave System™. R, X, and area under the reactance curve (AX) were measured at prime frequencies 7-41 Hz for 8 s.

RESULTS

In all, 86% of control infants had adequate measurements (coherence >0.8, CV < 0.25) on day 1. Infants with TTN had higher resistance at 13 Hz (TTN 32.5 cm H₂O·s/L [95% CI 25.5-39.4]; controls 23.8 cm H₂O·s/L [95% CI 22.2 to 25.3], P = 0.007) and lower reactance from 17 to 37 Hz (TTN -35.1 to -10.5; controls -26.3 to -6.1, P < 0.05). In healthy controls, lung mechanics were unchanged from days 1 to 3. In TTN, lung mechanics normalized on days 2 and 3.

CONCLUSIONS

FOT is feasible in neonates and distinguishes normal control infants from those with TTN on postnatal day 1. Oscillometry offers a non-invasive, longitudinal technique to assess lung mechanics in newborns.

Efficacy of Pidotimod use in treating allergic rhinitis in a pediatric population

Background

Allergic rhinitis (AR) and adenoidal hypertrophy (AH) are the most frequent causative disorders of nasal obstruction in children, leading to recurrent respiratory infections. Both nasal cavities are colonized by a stable microbial community susceptible to environmental changes and Staphylococcus aureus seems to play the major role. Furthermore, nasal microbiota holds a large number and variety of viruses with upper respiratory tract infections. This local microbiota deserves attention because its modification could induce a virtuous cross-talking with the immune system, with a better clearance of pathogens. Although AR and AH present a different etiopathogenesis, they have in common a minimal chronic inflammation surrounding nasal obstruction; hence it would be challenging to evaluate the effect of an immunomodulator on this minimal chronic inflammation with possible clinical and microbiological effects. The aim of this study is therefore to evaluate the efficacy of an immunomoldulator (Pidotimod) on nasal obstruction in children with AR and/or AH and whether its action involves a variation of nasal microbiota.

Methods

We enrolled 76 children: those with allergic rhinitis (AR) sensitized to dust mites entered the AR group, those with adenoidal hypertrophy (AH) the AH group, those with both conditions the AR/AH group and those without AR ± AH as controls (CTRL). At the first visit they performed: skin prick tests, nasal fiberoptic endoscopy, anterior rhinomanometry, nasal swabs. Children with.

AR ± AH started treatment with Pidotimod.

After 1 month they were re-evaluated performing the same procedures.

The primary outcome was the evaluation of nasal obstruction after treatment and the secondary outcome was the improvement of symptoms and the changes in nasal microflora.

Results

All patients improved their mean nasal flow (mNF) in respect to the baseline. In AR children mNF reached that one of CTRL. In AH children±AR the mNF was lower in respect to CTRL and AR group. We did not find any differences among all the groups at the two different time points in nasal microflora.

Conclusions

Pidotimod is able to give an improvement in nasal obstruction, especially in AR children but this effect seems to be not mediated by changes in nasal microbiota.

The Practical Significance of Measurement Error in Pulmonary Function Testing Conducted in Research Settings

Conventional spirometry produces measurement error by using repeatability criteria (RC) to discard acceptable data and terminating tests early when RC are met. These practices also implicitly assume that there is no variation across maneuvers within each test. This has implications for air pollution regulations that rely on pulmonary function tests to determine adverse effects or set standards. We perform a Monte Carlo simulation of 20,902 tests of forced expiratory volume in 1 second (FEV₁ ), each with eight maneuvers, for an individual with empirically obtained, plausibly normal pulmonary function. Default coefficients of variation for inter- and intratest variability (3% and 6%, respectively) are employed. Measurement error is defined as the difference between results from the conventional protocol and an unconstrained, eight-maneuver alternative. In the default model, average measurement error is shown to be ∼5%. The minimum difference necessary for statistical significance at p < 0.05 for a before/after comparison is shown to be 16%. Meanwhile, the U.S. Environmental Protection Agency has deemed single-digit percentage decrements in FEV₁ sufficient to justify more stringent national ambient air quality standards. Sensitivity analysis reveals that results are insensitive to intertest variability but highly sensitive to intratest variability. Halving the latter to 3% reduces measurement error by 55%. Increasing it to 9% or 12% increases measurement error by 65% or 125%, respectively. Within-day FEV₁ differences ≤5% among normal subjects are believed to be clinically insignificant. Therefore, many differences reported as statistically significant are likely to be artifactual. Reliable data are needed to estimate intratest variability for the general population, subpopulations of interest, and research samples. Sensitive subpopulations (e.g., chronic obstructive pulmonary disease or COPD patients, asthmatics, children) are likely to have higher intratest variability, making it more difficult to derive valid statistical inferences about differences observed after treatment or exposure.

Socioeconomic and Environmental Risk Factors for Pediatric Asthma in an American Indian Community

BACKGROUND

American Indian (AI)/Alaska Native children have increased asthma prevalence, morbidity, and mortality compared to non-Hispanic white children. Our study sought to examine environmental and socioeconomic factors of asthma among children in an AI community.

METHODS

This case-control study included children with physician-diagnosed asthma and age-matched controls, ages 6 through 17 years, in an AI community. Diagnosis and clinical characteristics were obtained from medical record review. Home visits included interviews regarding sociodemographic and household environmental exposures, physical exams, spirometry, and asthma control questionnaires (cases only).

RESULTS

Among the 108 asthma cases and 215 controls, 64% had an annual household income of <$25,000. Children with asthma had significantly higher odds of living in a multi-unit dwelling (odds ratio [OR], 2.3; 95% confidence interval [CI], 1.2-4.4) or in residences with rodent or insect infestation (OR, 2.1; 95% CI, 1.1-3.8) and were less likely to live in homes with more than 8 occupants (OR, 0.5; 95% CI, 0.3-0.9). Also, there was a trend for lower caregiver education level, unmarried caregiver marital status, and annual household income level of <$25,000 in univariate analysis. However, after adjustment for socioeconomic status and household environmental factors, these estimates were not significant. Nearly half of cases had poorly controlled asthma and reported persistent cough, wheeze, and dyspnea, yet only 24% reported using a controller medication.

CONCLUSIONS

In this low-income AI community, we identified several social and environmental determinants of asthma, which were mediated by socioeconomic status and other household environmental factors, suggesting a complex interplay between socioeconomic status and environmental exposures. Furthermore, many children with asthma reported poor asthma control.

Comparison of Pulmonary Function Decline in Steroid-Treated and Steroid-Naïve Patients with Duchenne Muscular Dystrophy

OBJECTIVE

To describe and compare the lung function decline in patients with Duchenne muscular dystrophy on glucocorticoid therapy in contrast with glucocorticoid-naïve patients, and to define the deciles of pulmonary decline in glucocorticoid-treated patients.

STUDY DESIGN

This retrospective study examined lung function of patients with Duchenne muscular dystrophy over 6 years of age followed between 2001 and 2015 at 2 centers-glucocorticoid-treated patients in Cincinnati, Ohio, and glucocorticoid-naïve patients in Paris, France. Forced vital capacity (FVC, FVC%), forced expiratory volume in 1 second, maximal inspiratory pressure, maximal expiratory pressure, and peak expiratory flow data were analyzed. Only FVC data were available for the French cohort.

RESULTS

There were 170 glucocorticoid-treated patients (92%), 5 patients (2.7%) with past glucocorticoid use, and 50 French glucocorticoid-naïve patients. The peak absolute FVC was higher and was achieved at earlier ages in glucocorticoid-treated compared with glucocorticoid-naïve patients (peak FVC, 2.4 ± 0.6 L vs 1.9 ± 0.7 L; P < .0001; ages 13.5 ± 3.0 years vs 14.3 ± 2.8 years; P = .03). The peak FVC% was also higher and was achieved at earlier ages in glucocorticoid-treated patients (peak FVC%, 105.1 ± 25.1% vs 56 ± 20.9%; P < .0001; ages 11.9 ± 2.9 years vs 13.6 ± 3.2 years; P = .002). Rates of decline for both groups varied with age. Maximal rates of decline were 5.0 ± 0.26% per year (12-20 years) for glucocorticoid-treated and 5.1 ± 0.39% per year for glucocorticoid-naïve patients (11-20 years; P = .2). Deciles of FVC% decline in glucocorticoid-treated patients show that patients experience accelerated decline at variable ages.

CONCLUSIONS

These data describe nonlinear rates of decline of pulmonary function in patients with Duchenne muscular dystrophy, with improved function in glucocorticoid-treated patients. FVC% deciles may be a useful tool for clinical and research use.

Xenon-129 MRI detects ventilation deficits in paediatric stem cell transplant patients unable to perform spirometry

BACKGROUND

Early detection of pulmonary morbidity following haematopoietic stem cell transplantation (HSCT) remains an important challenge for intervention, primarily due to the insensitivity of spirometry to early change, and in paediatrics, patient compliance provides additional challenges. Regional lung ventilation abnormalities in paediatric HSCT patients were quantified using hyperpolarised xenon-129 (129Xe) magnetic resonance imaging (MRI) and compared to spirometry.

METHODS

Medically stable, paediatric allogeneic HSCT patients (n=23, ages 6-16 years) underwent an outpatient MRI scan where regional ventilation was quantified with a breath-hold of hyperpolarised 129Xe gas. Ventilation deficits, regions of the lung that ventilate poorly due to obstruction, were quantified as a ventilation defect percentage (VDP) and compared to forced expiratory volume in 1 s (FEV1), FEV1/forced vital capacity (FVC) ratio, and forced expiratory flow at 25-75% of FVC (FEF25-75%) from spirometry using linear regression.

RESULTS

The mean±sd 129Xe VDP was 10.5±9.4% (range 2.6-41.4%). 129Xe VDP correlated with FEV1, FEV1/FVC ratio and FEF25-75% (p≤0.02 for all comparisons). Ventilation deficits were detected in patients with normal spirometry (i.e. FEV1 >80%), supporting the sensitivity of 129Xe MRI to early obstruction reported in other pulmonary conditions. Seven (30%) patients could not perform spirometry, yet ventilation deficits were observed in five of these patients, detecting abnormalities that otherwise may have gone undetected and untreated until advanced.

CONCLUSION

Lung ventilation deficits were detected using hyperpolarised 129Xe gas MRI in asymptomatic paediatric HSCT patients and in a subgroup who were unable to perform reliable spirometry. 129Xe MRI provides a reliable imaging-based assessment of pulmonary involvement in this potentially difficult to diagnose paediatric population.

Quantitative CT and pulmonary function in children with post-infectious bronchiolitis obliterans

Objective

To investigate the feasibility of CT-based quantitative airway and air-trapping measurements and to assess their correlation with pulmonary function in children with post-infectious bronchiolitis obliterans (PIBO).

Materials and methods

This retrospective study approved by the institutional review board included chest CT scans and pulmonary function tests (PFT) completed between January 2005 and December 2016 in children diagnosed with PIBO. The quantitative analysis of segmental and subsegmental bronchi was performed on each chest CT scan, measuring the areas or diameters of lumens, walls, or the entire airway. The air-trapping volume (ATV), the volume of lung area exhibiting lower attenuation than the mean attenuation of normal and air-trapping areas, was also measured in each lobe. Comparison analyses between CT parameters and PFT results were performed with Pearson or Spearman correlation.

Results

In total, 23 patients were enrolled (mean age 7.0 ± 3.3 years; range, 4–15 years). We successfully measured 89.6% of all segmental bronchi. In the airway analysis, wall area showed a negative correlation with forced expiratory volume in one second (FEV₁) in the majority of the pulmonary lobes. Air-trapping analyses demonstrated that ATV was negatively correlated with FEV₁ and positively correlated with reactance at 5 Hz.

Conclusion

Quantitative airway and air-trapping measurements from chest CT are feasible and correlate with pulmonary function in pediatric PIBO patients.

A randomized pilot trial of a school-based psychoeducational intervention for children with asthma

BACKGROUND

Asthma is a common childhood illness with high morbidity and mortality among minority and socio-economically disadvantaged children. Disparities are not fully accounted for by differences in asthma prevalence, highlighting a need for interventions targeting factors associated with poorer asthma control. One such factor is psychological stress.

OBJECTIVE

Here, we examine the feasibility and acceptability of "I Can Cope (ICC)," a school-based stress management and coping intervention for children with asthma.

METHODS

A parallel randomized pilot trial was conducted. One hundred and four low-income children (mean age 10 years; 54% male; 70% African American) with persistent asthma were recruited from 12 urban schools and randomized to the following: (a) ICC or one of two control conditions: (b) "Open Airways for Schools (OAS)"-an asthma education intervention or (c) no treatment.

RESULTS

Seventy one percentage of eligible children participated in the study, with a dropout rate of 12%. ICC was rated as highly acceptable by participating children and parents. Preliminary efficacy data suggest that when compared with no treatment, ICC resulted in decreased symptoms of depression, perceived stress and child-reported symptoms of asthma, and improvements in sleep quality and child-reported asthma control. There were no intervention-related changes in objective measures of asthma morbidity. The magnitude of intervention effects on psychological function did not differ between the ICC and OAS groups.

CONCLUSIONS

Results support the feasibility and acceptability of utilizing school-based interventions to access hard to reach children with asthma. Preliminary findings offer support for future, large-scale efficacy studies of school-based interventions designed to target multiple factors that contribute to asthma disparities.

Clinical course of chronic suppurative lung disease and bronchiectasis in Alaska Native children

INTRODUCTION

Alaska Native (AN) children from the Yukon Kuskokwim (YK) Delta region have high rates of chronic suppurative lung disease (CSLD), including bronchiectasis. We characterized the clinical progress of an AN adolescent cohort with CSLD/bronchiectasis, and estimated bronchiectasis prevalence trends in this region.

METHODS

The original cohort comprised 41 AN children (originally aged 0.5-8 years) with CSLD/bronchiectasis, recruited between 2005 and 2008, with follow-up in 2015-2016. Clinical assessments, lung function, radiography, medical chart review, and spirometry were obtained. We also conducted data queries of bronchiectasis diagnoses in YK individuals born between 1990 and 2010 to estimate prevalence.

RESULTS

Thirty-four (83%) of the original cohort aged 7.3-17.6 years were reviewed, of whom 14 (41%) had high-resolution computed tomography (HRCT)-confirmed bronchiectasis, eight (24%) had no evidence of bronchiectasis on HRCT scans, while 12 (35%) had not undergone HRCT scans. Annual lower respiratory tract infection (LRTI) frequency decreased with age, although 27 (79%) still had respiratory symptoms, including all with HRCT-confirmed bronchiectasis, who were also more likely than those without confirmed bronchiectasis to have recent wheeze (80 vs 25%, P = 0.005), auscultatory crackles (60 vs 0%, P < 0.001), and lower mean forced expiratory volume in 1-second/forced vital capacity ratio (73 vs 79%, P = 0.03). The bronchiectasis prevalence for YK AN people born during 2000-2009 was 7 per 1000 births, which was lower than previously reported.

CONCLUSION

Despite reduced LRTI frequency, most AN children with CSLD/bronchiectasis had symptoms/signs of underlying lung disease as they entered adolescence. Close clinical follow-up remains essential for managing these patients as they transition to adulthood.

SPIROMETRY IN SCHOOLCHILDREN FOR FIELD STUDIES: DOES TESTING ON DIFFERENT DAYS CHANGE THE RESULT OF THE EXAM?

OBJECTIVE

To analyze if there is variation in the results of spirometry performed by healthy schoolchildren on different days.

METHODS

Cross-sectional study with healthy schoolchildren aged 7 to 12 years old, in Florianópolis, Santa Catarina, Southern Brazil. Prepubescent children, non-athletes, born at full term, without cardiorespiratory, rheumatic, musculoskeletal, neurological and visual or hearing deficit were included. The child's health was assessed by a health questionnaire and by the survey International Study of Asthma and Allergies in Childhood. The spirometric test was performed on 3 different days, not exceeding the interval of 15 days between the first and last exams, following the guidelines of the American Thoracic Society. The absolute values and percentages of predicted values of forced vital capacity, forced volume in the first second and peak expiratory flow were analyzed. Statistical analysis was performed using the Shapiro-Wilk normality test followed by one-way analysis of variance or Friedman test and by Bonferroni's post-hoc test for multiple parametric comparisons. Also, the intraclass correlation coefficient was applied to compare results on the same patients on the different tested days.

RESULTS

Twenty-two children were analyzed, with a mean age of 9.3±1.1 years. All the spirometric parameters showed a reduction in absolute value after the first exam, but without significant difference. Regarding reproducibility of spirometry results, the tests presented intraclass correlation coefficient >0.70.

CONCLUSIONS

There was no change in the results of spirometry performed by healthy schoolchildren on three different days.

Overall and peripheral lung function assessment by spirometry and forced oscillation technique in relation to asthma diagnosis and control

BACKGROUND

Classic spirometry is effort dependent and of limited value in assessing small airways. Peripheral airway involvement, and relation to poor control, in asthma, has been highlighted recently. Forced oscillation technique (FOT) offers an effort-independent assessment of overall and peripheral lung mechanics. We studied the association between lung function variables, obtained either by spirometry or multifrequency (5, 11 and 19 Hz) FOT, and asthma diagnosis and control.

METHODS

Spirometry measures, resistance at 5 (R5) and 19 Hz (R19), reactance at 5 Hz (X5), resonant frequency (f_res ), resistance difference between 5-19 Hz (R5-R19) and Asthma Control Test scores were determined in 234 asthmatic and 60 healthy subjects (aged 13-39 years). We used standardized lung function variables in logistic regression analyses, unadjusted and adjusted for age, height, gender and weight.

RESULTS

Lower FEV₁ /FVC (OR [95% CI] 0.47 [0.32, 0.69]) and FEF₅₀ (0.62 [0.46, 0.85]) per standard deviation increase, and higher R5 (3.31 [1.95, 5.62]) and R19 (2.54 [1.65, 3.91]) were associated with asthma diagnosis. Independent predictive effects of FEV₁ /FVC and R5 or R19, respectively, were found for asthma diagnosis. Lower FEV₁ /FVC and altered peripheral FOT measures (X5, f_res and R5-R19) were associated with uncontrolled asthma (P-values < .05).

CONCLUSIONS

Resistance FOT measures were equally informative as spirometry, related to asthma diagnosis, and, furthermore, offered additive information to FEV₁ /FVC, supporting a complementary role for FOT. Asthma control was related to FOT measures of peripheral airways, suggesting a potential use in identifying such involvement. Further studies are needed to determine a clinical value and relevant reference values in children, for the multifrequency FOT measurements.

Physical activity, black carbon exposure, and DNA methylation in the FOXP3 promoter

Background

Physical activity is associated with improvement in lung function; however, pollution exposure during physical activity can lead to a transient reduction in lung function. This paradoxical relationship may be linked to altered T regulatory (Treg) cell activity, which increases with exercise and suppresses airway inflammation, but decreases in association with exposure to air pollution. To clarify these relationships, we investigated buccal cell DNA methylation of the forkhead box p3 (FOXP3) gene promoter, a proposed biomarker of Treg activity. We hypothesized that active urban children would have lower FOXP3 promoter methylation, associated with better lung function compared to non-active children. We also hypothesized that this relationship would be attenuated by high exposure to the air pollutant black carbon (BC).

Methods

We performed a cross-sectional study of 135 children ages 9–14 who live in New York City. Activity was measured across 6 days. BC exposure was assessed by personal monitors worn for two 24-h periods, followed by lung function assessment. Buccal swabs were collected for DNA methylation analysis of three regions (six CpG sites) in the FOXP3 promoter.

Results

In multivariable regression models, overall, there was no significant relationship between physical activity and FOXP3 promoter methylation (p > 0.05). However, in stratified analyses, among children with higher BC exposure (≥1200 ng/m³), physical activity was associated with 2.37% lower methylation in promoter 2 (CpGs −77, −65, and −58) (β_estimate = −2.37%, p < 0.01) but not among those with lower BC exposure (β_estimate = 0.54%, p > 0.05). Differences across strata were statistically significant (p_interaction = 0.04). Among all children, after controlling for BC concentration, promoter 2 methylation was associated with reduced FEV₁/FVC (β_estimate = −0.40%, p < 0.01) and reduced FEF_25–75% (β_estimate = −1.46%, p < 0.01).

Conclusions

Physical activity in urban children appeared associated with lower FOXP3 promoter methylation, a possible indicator of greater Treg function, under conditions of high BC exposure. Reduced FOXP3 promoter methylation was associated with higher lung function. These findings suggest that physical activity may induce immunologic benefits, particularly for urban children with greater risk of impaired lung function due to exposure to higher air pollution. FOXP3 promoter buccal cell methylation may function as a useful biomarker of that benefit.

Electronic supplementary material

The online version of this article (doi:10.1186/s13148-017-0364-0) contains supplementary material, which is available to authorized users.

Effect of variable backpack load and strap option on the pulmonary function of children: A simulation using treadmill walking

BACKGROUND

The restrictive effect of backpack loads on chest expansion has been widely reported but little is known whether pulmonary function in children is affected by the placement of the straps of the backpack.

OBJECTIVE

To determine the effects of strap configuration and backpack loads on pulmonary function among school age children.

METHODS

Eighteen children (mean age of 12±1.68 years) participated in this study. Pulmonary functionwas assessed using spirometryat baseline and during five test conditions. Two strap configurations were compared: double straps with the backpack worn midline on the back with one strap over each shoulder and single strap with the backpack worn laterally with one strap over the shoulder.

RESULTS

A marginal increase was shown in all measures of pulmonary function during standing and walking, and as the backpack weight increased. However, all the marginal changes in pulmonary function tests across different weights and strap patterns were not statistically significant.

CONCLUSION

Variable backpack loading and strap options appear to influence changes to the pulmonary function of children. Although the observed changes are marginal, it could not be determined if they have a long term effect. Further investigations of larger sample size are required to inform practice.

Infant lung function predicts asthma persistence and remission in young adults

BACKGROUND AND OBJECTIVE

Asthma in adults is associated with a persistent reduction in lung function from childhood, but this link has not been assessed back to infancy. Reduced infant lung function (ILF), a measure of antenatal and infant lung growth, is associated with asthma into adolescence. Our aim was to assess whether this link persists into adulthood and whether ILF can predict the remission of asthma symptoms in young adults.

METHODS

The study cohort was an unselected full-term birth cohort of 253 subjects enrolled antenatally with lung function assessments at 1, 6 and 12 months (maximum expiratory flow at functional residual capacity, V'maxFRC), and 6, 11, 18 and 24 years (spirometry) of age.

RESULTS

Infants with V'maxFRC in the lowest quartile at 1 month had an OR of 5.1 (95% CI: 2-13, P = 0.001) for asthma at 24 years. Subjects with asthma at 24 years had a mean V'maxFRC at 1 month of 69% predicted (95% CI: 48-90%) versus 110% (95% CI: 101-119%) in non-asthmatic patients (P = 0.001). Subjects with current versus resolved asthma symptoms at 24 years had a mean V'maxFRC at 1 month of 69% predicted (95% CI: 53-84%) versus 105% (88-123%), respectively (P = 0.003). Subjects with current asthma at 24 years had persistently lower lung function from infancy with a mean reduction of 16.2% (95% CI: 8.1-24.3%, P < 0.0001).

CONCLUSION

Reduced lung function in early infancy is predictive of persistent asthma in young adults and a persistent reduction in lung function, suggesting abnormal lung development and growth in utero or very early in life.

Frequência de sucesso de pré-escolares e escolares com e sem sintomas respiratórios nos testes de função pulmonar

RESUMO O objetivo deste estudo foi avaliar a frequência de sucesso de pré-escolares e escolares com e sem sintomas respiratórios nos testes de função pulmonar. Foram incluídas crianças e adolescentes com idade entre quatro e 12 anos com e sem sintomas respiratórios, baseados no questionário de doenças respiratórias. Os participantes foram recrutados em duas escolas e classificados, de acordo com sua faixa etária, em pré-escolares (4-6 anos) e escolares (7-12 anos). Foram coletados dados demográficos e antropométricos, além das variáveis dos testes de manovacuometria (PIMAX e PEMAX) e de espirometria (VEF1, CVF, VEF1/CVF e FEF25-75%). Os testes de função pulmonar foram considerados bem-sucedidos quando os participantes preenchiam os critérios de aceitabilidade e reprodutibilidade das diretrizes nacionais e internacionais. Para fins estatísticos, utilizou-se o teste de qui-quadrado e correlação de Pearson. Foram incluídos 148 participantes, com média de idade de 8,1±1,7 anos, sendo 51,4% do sexo feminino e 85,1% saudáveis. A taxa de sucesso no teste de manovacuometria e de espirometria foi de 91,9% e 91,2%, respectivamente. Houve uma taxa de sucesso significativamente menor no grupo de pré-escolares em comparação aos escolares, tanto para o teste de manovacuometria (p=0,044) como para o exame espirométrico (p=0,015). As correlações entre as variáveis do teste de manovacuometria e do exame espirométrico mostraram-se positivas e moderadas entre a PIMAX e a CVF, e a PEMAX e o VEF1 e FEF25-75%. Os achados demonstram uma frequência de sucesso significativamente menor no grupo etário pré-escolar em comparação com os sujeitos escolares em ambos os testes de função pulmonar avaliados.

Lessons learnt from a primary care asthma improvement project

Asthma is a very common disease that can occur at any age. In the UK and in many other countries it is mainly managed in primary care. The published evidence suggests that the key to improving diagnosis and management lies in better training and education rather than in the discovery of new medications. An asthma improvement project managed through the British Lung Foundation is attempting to do this. The project has three pilot sites: two in England supported by the Department of Health and one in Scotland supported by the Scottish Government. If the project is successful it will be rolled out to other health areas within the UK. The results of this project are not yet available. This article highlights the challenges encountered in setting up the project and may well be applicable to other areas in the UK and to other countries where similar healthcare systems exist. The encountered challenges reflect the complex nature of healthcare systems and electronic data capture in primary care. We discuss the differences between general practices in their ability and willingness to support the project, the training and education of their staff on asthma management, governance issues in relation to information technology systems, and the quality of data capture. Virtually all the challenges have now been overcome, but discussing them should ensure that others become aware of them at an early stage should they wish to undertake similar projects in the future.

Spirometry interpretation feasibility among pre-school children according to the European Respiratory Society and American Thoracic Society Guidelines

INTRODUCTION

Spirometry is the most used test to evaluate pulmonary function. Guidelines that defined acceptability and repeatability criteria for its implementation and interpretation among preschoolers were published in 2007. Our objective was to quantify the actual compliance with these criteria among pre-school patients.

METHODS

A review was performed on the baseline spirometry measured in patients aged 2 to 5 years in the Pediatric Respiratory Laboratory of the Pontificia Universidad Católica de Chile, who were admitted due to recurrent or persistent coughing or wheezing. Only those results obtained in patients who took the test for the first time were considered. They were analyzed by international standards.

RESULTS

A total of 93 spirometry results (mean age 57.4 ± 8.6 months, 48 males) were obtained, of which 44 (47%) met all acceptable criteria, 87 (93%) obtained expiratory time of ≥ 0.5seconds, and 67 (72%) of the patients had an end-expiratory flow of ≤10% from peak flow. The variation in the measurement of forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) was very low (intraclass correlation coefficient > 0.9).

CONCLUSION

It was possible to meet the acceptability and repeatability criteria for spirometry among pre-school children in our Center, which was similar to previous reports. As in older children, this test is fully recommended for pre-school children who require lung function studies.

Clinical characteristics of children and adolescents with severe therapy-resistant asthma in Brazil

OBJECTIVE

To describe the clinical characteristics, lung function, radiological findings, and the inflammatory cell profile in induced sputum in children and adolescents with severe therapy-resistant asthma (STRA) treated at a referral center in southern Brazil.

METHODS

We retrospectively analyzed children and adolescents (3-18 years of age) with uncontrolled STRA treated with high-dose inhaled corticosteroids and long-acting β2 agonists. We prospectively collected data on disease control, lung function, skin test reactivity to allergens, the inflammatory cell profile in induced sputum, chest CT findings, and esophageal pH monitoring results.

RESULTS

We analyzed 21 patients (mean age, 9.2 ± 2.98 years). Of those, 18 (86%) were atopic. Most had uncontrolled asthma and near-normal baseline lung function. In 4 and 7, induced sputum was found to be eosinophilic and neutrophilic, respectively; the inflammatory cell profile in induced sputum having changed in 67% of those in whom induced sputum analysis was repeated. Of the 8 patients receiving treatment with omalizumab (an anti-IgE antibody), 7 (87.5%) showed significant improvement in quality of life, as well as significant reductions in the numbers of exacerbations and hospitalizations.

CONCLUSIONS

Children with STRA present with near-normal lung function and a variable airway inflammatory pattern during clinical follow-up, showing a significant clinical response to omalizumab. In children, STRA differs from that seen in adults, further studies being required in order to gain a better understanding of the disease mechanisms.

Disparities in pulmonary function in healthy children across the Indian urban-rural continuum

RATIONALE

Marked socioeconomic health-care disparities are recognized in India, but lung health inequalities between urban and rural children have not been studied.

OBJECTIVES

We investigated whether differences exist in spirometric pulmonary function in healthy children across the Indian urban-rural continuum and compared results with those from Indian children living in the UK.

METHODS

Indian children aged 5 to 12 years were recruited from Indian urban, semiurban, and rural schools, and as part of the Size and Lung Function in Children study, London. Anthropometric and spirometric assessments were undertaken.

MEASUREMENTS AND MAIN RESULTS

Acceptable spirometric data were obtained from 728 (58% boys) children in India and 311 (50% boys) UK-Indian children. As an entire group, the India-resident children had significantly lower z FEV1 and z FVC than UK-Indian children (P < 0.0005), when expressed using Global Lung Function Initiative-2012 equations. However, when India-resident children were categorized according to residence, there were no differences in z FEV1 and z FVC between Indian-urban and UK-Indian children. There were, however, significant reductions of ∼ 0.5 z scores and 0.9 z scores in both FEV1 and FVC (with no difference in FEV1/FVC) in Indian-semiurban and Indian-rural children, respectively, when compared with Indian-urban children (P < 0.0005). z Body mass index, socioeconomic circumstances, tobacco, and biomass exposure were individually significantly associated with z FEV1 and z FVC (P < 0.0005).

CONCLUSIONS

The presence of an urban-rural continuum of lung function within a specific ethnic group emphasizes the impact of environmental factors on lung growth in emerging nations such as India, which must be taken into account when developing ethnic-specific reference values or designing studies to optimize lung health.

Impact of backpack type on respiratory muscle strength and lung function in children

We examine the influence of backpack type on lung function and respiratory muscle strength in children. Thirty-seven children were assessed for lung function and inspiratory and expiratory muscle strength under four randomly determined conditions: unloaded erect standing and three conditions carrying 15% of the child's body weight. In these three conditions, children carried the weight on a backpack with bilateral shoulder straps carried over both shoulders, on a backpack with bilateral shoulder straps carried over one shoulder and on a backpack with a mono shoulder strap. Significantly lower forced vital capacity, forced expiratory volume in one second and maximal expiratory pressure were observed when children carried a backpack with a mono shoulder strap compared to the unloaded standing position. In conclusion, the restrictive effect and the decrease in expiratory muscle strength were more pronounced for the backpack with a mono shoulder strap, suggesting that a double strap backpack is preferable to a mono shoulder strap backpack. Practitioner summary: There is little known about the effect of schoolbags on respiratory muscle function. We investigated the influence of backpack type on lung function and respiratory muscle strength. A backpack with a mono shoulder strap created a restrictive effect and a decrease in strength, suggesting that a double strap backpack is preferable to a mono shoulder strap backpack.

Atopy, cytokine production, and airway reactivity as predictors of pre-school asthma and airway responsiveness

BACKGROUND

Childhood asthma is often characterized by recurrent wheezing, airway hyper-reactivity, atopy, and altered immune characteristics; however, our understanding of the development of these relationships from early in life remains unclear. The aim of our study was to evaluate whether atopy, cytokine production by peripheral blood mononuclear cells (PBMCs), and airway responsiveness, assessed in infants and toddlers, are associated with asthma and airway responsiveness at 4-years of age.

METHODS

Infants with eczema (N = 116), enrolled prior to wheezing, were assessed at entry (mean age of 10.7 months), at 1-year follow-up (N = 112), and at 4-years of age (N = 94). Total serum IgE, specific IgE to allergens, and cytokines produced by stimulated PBMCs, were assessed at entry and 1-year follow-up. Spirometry was obtained at all 3-visits, while airway reactivity to methacholine was assessed at entry and 1-year follow-up, and bronchodilator (BD) responsiveness, as well as current asthma was assessed at 4-years of age.

RESULTS

We found that pre-school children with asthma had lower spirometry and a greater BD-response. Serum IgE, particularly to egg and/or milk, and altered cytokine production by PBMCs at entry to the study were associated with asthma, lower spirometry, and greater airway responsiveness at 4-years of age. In addition, we found that airway responsiveness, as well as spirometry, tracked from infancy to 4-years of age.

CONCLUSIONS

While spirometry and airway responsiveness track longitudinally from early in life, atopy and cytokine production by PBMCs are associated not only with an increased risk of pre-school asthma, but also lower spirometry and increased airway responsiveness.

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.

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.

Independent and synergistic associations of asthma and obesity with systemic inflammation in adolescents

INTRODUCTION

Both asthma and obesity often occur in the same individual. Each increases the risk of cardiovascular disease (CVD) with systemic inflammation likely playing a vital role. We examined the independent and synergistic associations of asthma and obesity with systemic inflammation using high-sensitivity C-reactive protein (hs-CRP) levels in adolescents.

METHODS

This study involves the cross-sectional design carried out in the adolescent and respiratory medicine practices in a children's hospital. Out of 124 adolescents (mean age 16.1 ± 2.3 years), who were either of obese (N = 75) or of normal weight (N = 49). 51 had asthma (18 normal weight and 33 obese).

RESULTS

hs-CRP levels were higher in obese versus normal weight groups (geometric mean ± SD: 2.38 ± 2.91 vs. 0.72 ± 3.54; p < .001), and in the asthmatic versus non-asthmatic groups (geometric mean ± SD: 1.21 ± 3.71 vs.1.96 ± 3.28; p = .039). We found a trend of increasing hs-CRP levels across the four groups (p < .001), with the obese asthmatic group having the highest level. In multivariate regression, we found a strong association between obesity and log-CRP (β ± SE: 1.43 ± 0.23; p < .001) and a moderate association between asthma and log-CRP (β ± SE: 0.48 ± 0.21; p < .028), with additive synergy between obesity and asthma.

CONCLUSIONS

Both asthma and obesity are independently and synergistically associated with systemic inflammation. These findings underline the need of a multifaceted approach to address CVD risk in adolescence.

Associations of obesity and asthma with functional exercise capacity in urban minority adolescents

PURPOSE

To examine the independent association of asthma and obesity and of their co-existence with functional exercise capacity among urban adolescents.

METHODS

One hundred eighteen Hispanic- and African-American adolescents including 33 obese asthmatics, 18 normal-weight asthmatics, 38 obese non-asthmatics, and 29 normal-weight non-asthmatics underwent anthropometric measures, 6-minute walk test (6MWT) as measure of functional exercise capacity and spirometry as measure of pulmonary function. The 6-minute walk distance (6MWD) was compared between the four study groups. The association of 6MWD with measures of lower airway obstruction, and measures of adiposity was assessed.

RESULTS

The 6MWD was lower among the obese groups with the least distance covered by the obese asthmatic group (P = 0.02). In the obese asthmatic group, there was a negative correlation between 6MWD and body mass index (BMI) (r = -0.35, P = 0.03), but no association was noted with percent-predicted forced expiratory volume in the 1st second (FEV(1) ; r = 0.07, P = 0.70). Conversely, the 6MWD correlated with FEV(1) among normal-weight asthmatics (r = 0.45, P = 0.04) and normal-weight non-asthmatics (r = 0.4, P = 0.03), but was not associated with BMI in either of the two groups. After adjusting for age, height, gender, and ethnicity, BMI was noted to be a significant predictor (β -2.76, 95% CI -4.77 to -0.76, P < 0.01) of the 6MWD among the obese while percent predicted FEV(1) (β 1.87, 95% CI 0.28-3.45, P = 0.02) was a significant predictor among the normal-weight participants.

CONCLUSIONS

Our findings suggest that among urban minority obese asthmatic adolescents, functional exercise capacity was associated with obesity, rather than pulmonary function.

Early termination of exhalation: effect on spirometric parameters in healthy preschool children

OBJECTIVE

To evaluate the acceptability and reproducibility of spirometry in preschool children; to estimate the effect size of early termination of exhalation (ETE) on FVC, FEV(1) and FEV(0.5); and to evaluate the validity of FEV(0.5) in curves with ETE.

METHODS

Spirometric data were obtained from 240 healthy preschool children, who were selected by simple sampling. On the basis of the best curve from each child according to the end of exhalation, three groups were formed: no ETE (nETE); ETE and flow ≤ 10% of the highest PEF (ETE≤10); and ETE and flow > 10% of the highest PEF value (ETE>10). The reproducibility of FVC, FEV(1) and FEV(0.5) was compared among the three groups. The effect of ETE on FVC, FEV(1), and FEV(0.5) was assessed.

RESULTS

Of the 240 children tested, 112 (46.5%)-82 (34.0%) of those in the nETE group and 30 (12.5%) of those in the ETE≤10 group--had acceptable curves for all the parameters. In 64 (27.0%) of those in the ETE>10 group, the curves were acceptable only for FEV(0.5), increasing the proportion of children with valid FEV(0.5) to 73.0%. There were no significant differences between the nETE and ETE≤10 groups in terms of the mean values of the parameters assessed.

CONCLUSIONS

Maneuvers with ETE and flow ≤ 10% of the highest PEF are valid. In individuals with a flow > 10% of the highest PEF value, these maneuvers are only valid for FEV(0.5).

Risk factors for childhood asthma deaths from the UK Eastern Region Confidential Enquiry 2001-2006

BACKGROUND

Confidential enquiries into asthma deaths can identify inadequacies in medical management and factors which contribute to patients' death.

AIMS

To identify risk factors for paediatric asthma deaths over a 6-year period.

METHODS

Observational case-series study of paediatric asthma deaths between 2001-2006 in the UK Eastern Region. Hospital, primary care and post-mortem data were obtained for every child (≤17 yrs) with asthma recorded on the death certificate, and a detailed questionnaire was completed. Information was obtained on asthma severity, medications, hospital admissions, GP and hospital follow-up, adherence, psychosocial / behavioural factors, allergies, details of the terminal attack and precipitating factors.

RESULTS

20 children (10 male; 8-17 yrs; median: 11.5 yrs) died of asthma between 2001-2006. 9/20 had mild to moderate asthma (BTS/ SIGN criteria), 10/20 had severe asthma and 1 child was not known to have asthma. 13/20 were clinically atopic. Only 3 had undergone allergy assessment. 10/20 died between June and August. 12/20 children had adverse psychosocial and behavioural factors. 7/20 children were on non-combination long-acting β2-agonist (LABA) treatment without inhaled corticosteroids (ICS).

CONCLUSIONS

Almost half the deaths occurred in children with mild/moderate asthma. We recommend that allergic factors and seasonal allergy should be identified early, non-combination LABAs avoided, and speculate that overuse of short-acting β2-agonists (SABAs) may indicate non-adherence with ICS. Asthma deaths in children can be avoided if risk factors are identified early.