Respiratory disease and respiratory physiology: putting lung function into perspective: paediatric asthma

Skin Barrier Function and Infant Tidal Flow-Volume Loops-A Population-Based Observational Study

Background: The relationship between the skin barrier- and lung function in infancy is largely unexplored. We aimed to explore if reduced skin barrier function by high transepidermal water loss (TEWL), or manifestations of eczema or Filaggrin (FLG) mutations, were associated with lower lung function in three-month-old infants. Methods: From the population-based PreventADALL cohort, 899 infants with lung function measurements and information on either TEWL, eczema at three months of age and/or FLG mutations were included. Lower lung function by tidal flow-volume loops was defined as a ratio of time to peak tidal expiratory flow to expiratory time (tPTEF/tE) <0.25 and a tPTEF <0.17 s (<25th percentile). A high TEWL >8.83 g/m2/h (>75th percentile) denoted reduced skin barrier function, and DNA was genotyped for FLG mutations (R501X, 2282del4 and R2447X). Results: Neither a high TEWL, nor eczema or FLG mutations, were associated with a lower tPTEF/tE. While a high TEWL was associated with a lower tPTEF; adjusted OR (95% CI) 1.61 (1.08, 2.42), the presence of eczema or FLG mutations were not. Conclusions: Overall, a high TEWL, eczema or FLG mutations were not associated with lower lung function in healthy three-month-old infants. However, an inverse association between high TEWL and tPTEF was observed, indicating a possible link between the skin barrier- and lung function in early infancy.

Theoretical and contextual considerations for self-management strategies of children and adolescents with chronic diseases: An integrative review

The primary aim of this integrative review was to critically evaluate and synthesize published, peer-reviewed research to better understand self-management strategies of children and adolescents with chronic diseases. This review was guided by Whittemore and Knafl's methodological framework. The Pediatric Self-management Model provided the theoretical framework for understanding how self-management behaviors operate within the domains of individual, family, community, and healthcare systems. In June 2019, the electronic databases of EBSCOhost, PubMed, and Scopus, along with reference lists of applicable studies, were searched for appropriate publications. The initial searches yielded 920 citations. Of these, 11 studies met inclusion criteria. A key finding was that involving children and adolescents in the design and delivery phases of interventions was most effective in improving self-management when the interventions did not outweigh cognitive ability or maturity level. In addition, incorporating self-efficacy promotion into self-management interventions may lead to greater sense of responsibility and improved health outcomes. In terms of intervention delivery of self-management strategies, the use of technological platforms and devices was revealed as a promising avenue for youth. A final implication was the importance of family members, peers, and healthcare providers in supporting children and adolescents in adopting self-management behaviors.

Variation in pulmonary function tests among children with sickle cell anemia: a systematic review and meta-analysis

Introduction

the spectrum of pulmonary complications in sickle cell anemia (SCA) comprises mainly of acute chest syndrome (ACS), pulmonary hypertension (PH) and airway hyper-responsiveness (AHR). This study was conducted to examine the abnormalities in pulmonary function tests (PFTs) seen in children with SCA.

Methods

electronic databases (Cochrane library, PubMed, EMBASE, Scopus, Web of Science) were used as data sources. Two authors independently reviewed studies. All case-control studies with PFT performed in patients with SCA and normal controls were reviewed. Pulmonary functions were assessed with the help of spirometry, lung volume and gas diffusion findings.

Results

nine studies with 788 SCA children and 1101 controls were analyzed. For all studies, the pooled mean difference for forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), FEV1/FVC ratio, peak expiratory flow rate (PEFR), total lung capacity (TLC) and carbon mono-oxide diffusing capacity (DLCO) were -12.67, (95% CI: -15.41,-9.94), -11.69, (95% CI: -14.24, -9.14), -1.90, (95% CI: -4.32, 0.52), -3.36 (95% CI: -6.69, -0.02), -7.35, (95% CI: -14.97, -0.27) and -4.68, (95% CI -20.64, -11.29) respectively. FEV1 and FVC and were the only parameters found to be significantly decreased.

Conclusion

sickle cell anemia was associated with lower FEV1 and FVC, thus, supporting the role of routine monitoring for the progression of lung function decline in children with SCA with ACS. We recommend routine screening and lung function monitoring for early recognition of pulmonary function decline.

Validation of a Portable Game Controller to Assess Peak Expiratory Flow Against Conventional Spirometry in Children: Cross-sectional Study

BACKGROUND

International asthma guidelines recommend the monitoring of peak expiratory flow (PEF) as part of asthma self-management in children and adolescents who poorly perceive airflow obstruction, those with a history of severe exacerbations, or those who have difficulty controlling asthma. Measured with a peak flow meter, PEF represents a person's maximum speed of expiration and helps individuals to follow their disease evolution and, ultimately, to prevent asthma exacerbations. However, patient adherence to regular peak flow meter use is poor, particularly in pediatric populations. To address this, we developed an interactive tablet-based game with a portable game controller that can transduce a signal from the user's breath to generate a PEF value.

OBJECTIVE

The purpose of this study was to evaluate the concordance between PEF values obtained with the game controller and various measures derived from conventional pulmonary function tests (ie, spirometry) and to synthesize the participants' feedback.

METHODS

In this cross-sectional multicenter study, 158 children (aged 8-15 years old) with a diagnosis or suspicion of asthma performed spirometry and played the game in one of two hospital university centers. We evaluated the correlation between PEF measured by both the game controller and spirometry, forced expiratory volume at 1 second (FEV₁), and forced expiratory flow at 25%-75% of pulmonary volume (FEF_25-75), using Spearman correlation. A Bland-Altman plot was generated for comparison of PEF measured by the game controller against PEF measured by spirometry. A post-game user feedback questionnaire was administered and analyzed.

RESULTS

The participants had a mean age of 10.9 (SD 2.5) years, 44% (71/158) were female, and 88% (139/158) were White. On average, the pulmonary function of the participants was normal, including FEV₁, PEF, and FEV₁/forced vital capacity (FVC). The PEF measured by the game controller was reproducible in 96.2% (152/158) of participants according to standardized criteria. The PEF measured by the game controller presented a good correlation with PEF measured by spirometry (r=0.83, P<.001), with FEV₁ (r=0.74, P<.001), and with FEF_25-75 (r=0.65, P<.001). The PEF measured by the game controller presented an expected mean bias of -36.4 L/min as compared to PEF measured by spirometry. The participants' feedback was strongly positive, with 78.3% (123/157) reporting they would use the game if they had it at home.

CONCLUSIONS

The game controller we developed is an interactive tool appreciated by children with asthma, and the PEF values measured by the game controller are reproducible, with a good correlation to values measured by conventional spirometry. Future studies are necessary to evaluate the clinical impact this novel tool might have on asthma management and its potential use in an out-of-hospital setting.

Tidal breathing parameters measured by structured light plethysmography in children aged 2-12 years recovering from acute asthma/wheeze compared with healthy children

Measurement of lung function can be difficult in young children. Structured light plethysmography (SLP) is a novel, noncontact method of measuring tidal breathing that monitors displacement of the thoraco-abdominal wall. SLP was used to compare breathing in children recovering from an acute exacerbation of asthma/wheeze and an age-matched cohort of controls. Children aged 2-12 years with acute asthma/wheeze (n = 39) underwent two 5-min SLP assessments, one before bronchodilator treatment and one after. SLP was performed once in controls (n = 54). Nonparametric comparisons of patients to healthy children and of pre-bronchodilator to post-bronchodilator were made for all children, and also stratified by age group (2-5 vs. 6-12 years old). In the asthma/wheeze group, IE50_SLP (inspiratory to expiratory flow ratio) was higher (median 1.47 vs. 1.31; P = 0.002), thoraco-abdominal asynchrony (TAA) and left-right asynchrony were greater (both P < 0.001), and respiratory rate was faster (P < 0.001) than in controls. All other timing indices were shorter and displayed reduced variability (all P < 0.001). Variability in time to peak inspiratory flow was also reduced (P < 0.001). Younger children showed a greater effect than older children for TAA (interaction P < 0.05). After bronchodilator treatment, the overall cohort showed a reduction in within-subject variability in time to peak expiratory flow only (P < 0.001). Younger children exhibited a reduction in relative contribution of the thorax, TAA, and variability in TAA (interaction P < 0.05). SLP can be successfully performed in young children. The potential of SLP to monitor diseases such as asthma in children is worthy of further investigation. ClinicalTrials.gov identifier: NCT02543333.

The effect of early growth patterns and lung function on the development of childhood asthma: a population based study

BACKGROUND

Infant weight gain is associated with lower lung function and a higher risk of childhood asthma. Detailed individual childhood growth patterns might be better predictors of childhood respiratory morbidity than the difference between two weight and height measurements. We assessed the associations of early childhood growth patterns with lung function and asthma at the age of 10 years and whether the child's current body mass index (BMI) influenced any association.

METHODS

We derived peak height and weight growth velocity, BMI at adiposity peak, and age at adiposity peak from longitudinally measured weight and height data in the first 3 years of life of 4435 children enrolled in a population-based prospective cohort study. At 10 years of age, spirometry was performed and current asthma was assessed by questionnaire. Spirometry outcomes included forced vital capacity (FVC), forced expiratory volume in 1 s (FEV₁), FEV₁/FVC ratio, and forced expiratory flow after exhaling 75% of vital capacity (FEF₇₅).

RESULTS

Greater peak weight velocity was associated with higher FVC but lower FEV₁/FVC and FEF₇₅. Greater BMI at adiposity peak was associated with higher FVC and FEV₁ but lower FEV₁/FVC and FEF₇₅. Greater age at adiposity peak was associated with higher FVC, FEV₁, FEV₁/FVC and FEF₇₅, particularly in children with a small size at birth, and lower odds of current asthma in boys. The child's current BMI only explained the associations of peak weight velocity and BMI at adiposity peak with FVC and FEV₁. Peak height velocity was not consistently associated with impaired lung function or asthma.

CONCLUSION

Peak weight velocity and BMI at adiposity peak were associated with reduced airway patency in relation to lung volume, whereas age at adiposity peak was associated with higher lung function parameters and lower risk of asthma at 10 years, particularly in boys.

Tidal breathing parameters measured using structured light plethysmography in healthy children and those with asthma before and after bronchodilator

Structured light plethysmography (SLP) is a light‐based, noncontact technique that measures tidal breathing by monitoring displacements of the thoracoabdominal (TA) wall. We used SLP to measure tidal breathing parameters and their within‐subject variability (v) in 30 children aged 7–16 years with asthma and abnormal spirometry (forced expiratory volume in 1 sec [FEV1] <80% predicted) during a routine clinic appointment. As part of standard care, the reversibility of airway obstruction was assessed by repeating spirometry after administration of an inhaled bronchodilator. In this study, SLP was performed before and after bronchodilator administration, and also once in 41 age‐matched controls. In the asthma group, there was a significant increase in spirometry‐assessed mean FEV1 after administration of bronchodilator. Of all measured tidal breathing parameters, the most informative was the inspiratory to expiratory TA displacement ratio (IE50_SLP, calculated as TIF50_SLP/TEF50_SLP, where TIF50_SLP is tidal inspiratory TA displacement rate at 50% of inspiratory displacement and TEF50_SLP is tidal expiratory TA displacement rate at 50% of expiratory displacement). Median (m) IE50_SLP and its variability (vIE50_SLP) were both higher in children with asthma (prebronchodilator) compared with healthy children (mIE50_SLP: 1.53 vs. 1.22, P < 0.001; vIE50_SLP: 0.63 vs. 0.47, P < 0.001). After administration of bronchodilators to the asthma group, mIE50_SLP decreased from 1.53 to 1.45 (P = 0.01) and vIE50_SLP decreased from 0.63 to 0.60 (P = 0.04). SLP‐measured tidal breathing parameters could differentiate between children with and without asthma and indicate a response to bronchodilator.

Fractional exhaled nitric oxide and multiple breath nitrogen washout in preschool healthy and asthmatic children

INTRODUCTION

Objectively assessing pulmonary disease is challenging in preschool children with asthma. We evaluated the feasibility of measuring fractional exhaled nitrogen oxide (FeNO) and multiple breath nitrogen washout (N₂MBW) in children. We compared their capacities for discriminating between children with asthma and healthy controls.

METHODS

We measured FeNO and N₂MBW-derived indices of lung clearance (LCI_2.5) and conductive and acinar ventilation heterogeneity (S_cond and S_acin) in 65 preschool children; 35 with physician-diagnosed asthma and 30 healthy. FeNO was measured with a portable device (sampling time, 6 s). We employed data quality control guidelines on N₂MBW. Feasibility was evaluated in a maximum of 8 attempts for both methods. Atopic co-morbidity and first-degree disposition were evaluated with the ISAAC-questionnaire.

RESULTS

FeNO and N₂MBW testing were feasible in 45% and 91% of children, respectively. Feasibility was highly age-dependent. In children under 4 years old, FeNO was not feasible, but N₂MBW was 85% feasible. Children with asthma had significantly elevated S_cond values (median; 95% CI) (0.024; 0.020; 0.029) compared to healthy controls (0.019; 0.016; 0.023), but similar FeNO, LCI_2.5 and S_acinvalues.

CONCLUSION

The feasibility of measuring FeNO was highly age-dependent and not applicable in children under age 4. N₂MBW was feasible in the majority of preschool children. S_cond, but not FeNO, could discriminate between children with asthma and healthy controls.

Use of Global initiative for asthma (GINA) guidelines in asthma management among paediatric residents in a Sub Saharan African country: a cross-sectional descriptive study

Introduction

Clinical practice guidelines are systematically developed statements to assist practitioner and patient decisions about appropriate health care for specific clinical circumstances. Despite abundance of asthma guidelines, prevalence has continued to increase globally. There is need to assess how the contents of asthma guidelines are put to clinical use by doctors in the management of children with asthma. This study aims at evaluating the clinical practice of paediatric residents in applying GINA guidelines.

Methods

Cross-sectional descriptive study of paediatric residents from 23 university teaching hospitals in Nigeria using structured questionnaire. Data analyses were with Statistical Package for Social Sciences (SPSS) version 19 (Chicago IL). Chi square was used to assess for any significant associations between categorical variables. A p < 0.05 was regarded to be statistically significant.

Results

Sixty-six paediatric residents aged 27- 40 years were enrolled into the study (37 females and 29 males). One-third had spent more than three years in residency training. Fifty-eight residents (87.9%) were aware of the GINA guidelines while 46 (69.7%) were familiar with its contents. Only 39 (59.1%) residents adhered to the GINA guidelines. Twenty of the 35 junior residents (57.1%) compared to 26 of 31 (83.9%) senior residents were familiar with the GINA guidelines (p=0.031) while 15 of 35 junior residents (42.9%) compared to 24 of 31 senior residents (77.4%) consistently follow the GINA guidelines (p=0.006). Adherence to GINA guidelines was not influenced significantly by years of graduation or training (p>0.05).

Conclusion

The use of the GINA guidelines was poor among paediatric residents. Application of contents rather than just availability of asthma guidelines may partly account for increasing asthma prevalence globally.