Long-term pulmonary outcomes in BPD throughout the life-course

Respiratory disease is one of the most common complications of preterm birth. Survivors of prematurity have increased risks of morbidities and mortalities independent of prematurity, and frequently require multiple medications, home respiratory support, and subspecialty care to maintain health. Although advances in neonatal and pulmonary care have improved overall survival, earlier gestational age, lower birth weight, chorioamnionitis and late onset sepsis continue to be major factors in the development of bronchopulmonary dysplasia. These early life events associated with prematurity can have respiratory consequences that persist into adulthood. Furthermore, after initial hospital discharge, air pollution, respiratory tract infections and socioeconomic status may modify lung growth trajectories and influence respiratory outcomes in later life. Given that the incidence of respiratory disease associated with prematurity remains stable or increased, there is a need for pediatric and adult providers to be familiar with the natural history, manifestations, and common complications of disease.

Continuous Neuromuscular Blockade for Bronchopulmonary Dysplasia

OBJECTIVE

 Bronchopulmonary dysplasia (BPD) is the most common late morbidity for premature infants. Continuous neuromuscular blockade (CNMB) is suggested for the most unstable phase of BPD, despite no outcome data. We explored the association between duration of CNMB for severe BPD and mortality.

DESIGN

 Medical record review of children <5 years old admitted from 2016 to 2022 with BPD and one or more course of CNMB for ≥14 days.

RESULTS

 Twelve children received a total of 20 episodes of CNMB for ≥14 days (range 14-173 d) during their hospitalization. Most (10/12) were born at <28 weeks' gestation and most (11/12) with birth weight <1,000 g; 7/12 were of Black race/ethnicity. All were hospitalized since birth. Most (10/12) were initially transferred from an outside neonatal intensive care unit (ICU), typically after a >60-day hospitalization (9/12). Half (6/12) of them had a ≥60-day stay in our neonatal ICU before transferring to our pediatric ICU for, generally, ≥90 days (8/12). The primary study outcome was survival to discharge: 2/12 survived. Both had shorter courses of CNMB (19 and 25 d); only one child who died had a course ≤25 days. Just two infants had increasing length Z-scores during hospitalization; only one infant had a final length Z-score > - 2.

CONCLUSION

 In this case series of infants with severe BPD, there were no survivors among those receiving ≥25 days of CNMB. Linear growth, an essential growth parameter for infants with BPD, decreased in most patients. These data do not support the use of ≥25 days of CNMB to prevent mortality in infants with severe BPD.

KEY POINTS

· This is a case series of neuromuscular blockade for severe BPD.. · Neuromuscular blockade did not improve linear growth.. · Ten out of 12 infants who were on prolonged neuromuscular blockade died..

Human Milk Cessation in the NICU in Infants with Bronchopulmonary Dysplasia

OBJECTIVE

 The objective of this study was to identify factors associated with the cessation of human milk prior to neonatal intensive care unit (NICU) discharge for infants diagnosed with bronchopulmonary dysplasia (BPD).

STUDY DESIGN

 Participants were recruited from the Johns Hopkins BPD Clinic between January 2016 and October 2018. Clinical and demographic characteristics were analyzed based on whether participants stopped human milk before or after NICU discharge.

RESULTS

 Of the 224 infants included, 109 (48.7%) infants stopped human milk prior to discharge. The median duration of human milk intake was less for infants who stopped human milk prior to discharge compared with those who continued after discharge (2 vs. 8 months, p < 0.001). In multivariate regression analysis, pulmonary hypertension (odds ratio [OR]: 2.90; p = 0.016), public insurance (OR: 2.86; p < 0.001), and length of NICU admission (OR: 1.26 per additional month; p = 0.002) were associated with human milk cessation prior to NICU discharge.

CONCLUSION

 Infants with BPD who have severe medical comorbidities and markers of lower socioeconomic status may be at higher risk for earlier human milk discontinuation.

KEY POINTS

· Half of infants in our study with BPD who received human milk stopped human milk prior to NICU discharge.. · For infants on human milk after discharge, the duration of human milk intake was 8.6 months.. · Infants with pulmonary hypertension, tracheostomies, and ventilation stopped human milk earlier.. · Non-White race, lower income, and public insurance were predictors of early human milk cessation..

Long-term outcomes of infants with severe BPD

Preterm birth disrupts the normal sequence of lung development. Additionally, interventions that support gas exchange, including positive pressure ventilation and supplemental oxygen can further exacerbate lung injury, increasing the risk of developing bronchopulmonary dysplasia (BPD) in infants born preterm. Approximately 50,000 preterm infants each year in the United States develop BPD. Heterogeneous lung pathology involving the upper and lower respiratory tract can contribute to the BPD phenotype and can be age-dependent. These phenotypes include alveolar, upper airway, large airways, small airways, and vascular. Each of these phenotypes may improve, resolve, or persist at different ages, throughout childhood. The development of BPD endotypes can be influenced by gestational age and length and type of respiratory support. Although, long-term pulmonary outcomes of infants with severe BPD are variable, the presence of small airway disease is a common phenotype in school age and adolescent children. In this review we examine the more common respiratory endotypes found in infants and children with severe BPD and discuss the long-term prognosis for cardiovascular, neurological, and gastrointestinal morbidities in this patient population.

Number of children in the household influences respiratory morbidities in children with bronchopulmonary dysplasia in the outpatient setting

BACKGROUND

Bronchopulmonary dysplasia (BPD), a common complication of prematurity, is associated with outpatient morbidities, including respiratory exacerbations. Daycare attendance is associated with increased rates of acute and chronic morbidities in children with BPD. We sought to determine if additional children in the household conferred similar risks for children with BPD.

METHODS

The number of children in the household and clinical outcomes were obtained via validated instruments for 933 subjects recruited from 13 BPD specialty clinics in the United States. Clustered logistic regression models were used to test for associations.

RESULTS

The mean gestational age of the study population was 26.5 ± 2.2 weeks and most subjects (69.1%) had severe BPD. The mean number of children in households (including the subject) was 2.1 ± 1.3 children. Each additional child in the household was associated with a 13% increased risk for hospital admission, 13% increased risk for antibiotic use for respiratory illnesses, 10% increased risk for coughing/wheezing/shortness of breath, 14% increased risk for nighttime symptoms, and 18% increased risk for rescue medication use. Additional analyses found that the increased risks were most prominent when there were three or more other children in the household.

CONCLUSIONS

We observed that additional children in the household were a risk factor for adverse respiratory outcomes. We speculate that secondary person-to-person transmission of respiratory viral infections drives this finding. While this risk factor is not easily modified, measures do exist to mitigate this disease burden. Further studies are needed to define best practices for mitigating this risk associated with household viral transmission.

Ambient Air Pollution and Outpatient Morbidities in Bronchopulmonary Dysplasia

Rationale: Bronchopulmonary dysplasia (BPD) is the most common long-term complication of prematurity. Although socioeconomic status is associated with BPD morbidities, the drivers of this association are poorly understood. In the United States, ambient air pollution (AAP) exposure is linked to both race/ethnicity and socioeconomic status. Furthermore, AAP exposure is known to have a detrimental effect on respiratory health in children. Objectives: To assess if AAP exposure is linked to BPD morbidity in the outpatient setting. Methods: Participants with BPD were recruited from outpatient clinics at Johns Hopkins University and the Children's Hospital of Philadelphia between 2008 and 2021 (N = 800) and divided into low, moderate, and high AAP exposure groups, based on publicly available U.S. Environmental Protection Agency data. Clinical data were obtained by chart review and caregiver questionnaires. Results: Non-White race, home ventilator use, and lower median household income were associated with higher degrees of air pollution exposure. After adjustment for these factors, moderate and high air pollution exposure were associated with requiring systemic steroids (odds ratio, 1.78 and 2.17, respectively) compared with low air pollution. Similarly, high air pollution exposure was associated with emergency department visits (odds ratio, 1.59). Conclusions: This study demonstrates an association between AAP exposure and BPD morbidity after initial hospital discharge. AAP exposure was closely linked to race and median household income. As such, it supports the notion that AAP exposure may be contributing to health disparities in BPD outcomes. Further studies directly measuring exposure and establishing a link between biomarkers of exposure and outcomes are prerequisites to developing targeted interventions protecting this vulnerable population.

Actigraphy methodology in the Kids Mod PAH trial: Physical activity as a functional endpoint in pediatric clinical trials

Pulmonary vasodilator treatment can improve hemodynamics, right ventricular function, symptoms, and survival in pediatric pulmonary hypertension (PH). However, clinical trial data are lacking due to many constraints. One major limitation is the lack of relevant trial endpoints reflective of hemodynamics or functional status in patients in whom standard exercise testing is impractical, unreliable, or not reproducible. The Kids Mod PAH trial (Mono- vs. Duo Therapy for Pediatric Pulmonary Arterial Hypertension) is an ongoing multicenter, Phase III, randomized, open-label, pragmatic trial to compare the safety and efficacy of first-line combination therapy (sildenafil and bosentan) to first-line monotherapy (sildenafil alone) in 100 pediatric patients with PH across North America. Investigators will measure participants' physical activity with a research-grade, wrist-worn actigraphy device at multiple time points as an exploratory secondary outcome. Vector magnitude counts per minute and activity intensity will be compared between the treatment arms. By directly and noninvasively measuring physical activity in the ambulatory setting, we aim to identify a novel, simple, inexpensive, and highly reproducible approach for quantitative assessment of exercise tolerance in pediatric PH. These data will increase the field's understanding of the effect of pulmonary vasodilator treatment on daily activity - a quantitative measure of functional status and wellbeing in pediatric PH and a potential primary outcome for future clinical trials in children with cardiopulmonary disorders.

Kids Mod PAH trial: A multicenter trial comparing mono- versus duo-therapy for initial treatment of pediatric pulmonary hypertension

Pulmonary hypertension (PH) is a significant health problem that contributes to high morbidity and mortality in diverse cardiac, pulmonary, and systemic diseases in children. Evidence-based advances in PH care have been challenged by a paucity of quality endpoints for assessing clinical course and the lack of robust clinical trial data to guide pharmacologic therapies in children. While the landmark adult AMBITION trial demonstrated the benefit of up-front combination PH therapy with ambrisentan and tadalafil, it remains unknown whether upfront combination therapy leads to more rapid and sustained clinical benefits in children with various categories of PH. In this article, we describe the inception of the Kids Mod PAH Trial, a multicenter Phase III trial, to address whether upfront combination therapy (sildenafil and bosentan vs. sildenafil alone) improves PH outcomes in children, recognizing that marked differences between the etiology and therapeutic response between adults and children exist. The primary endpoint of this study is WHO functional class (FC) 12 months after initiation of study drug therapy. In addition to the primary outcome, secondary endpoints are being assessed, including a composite measure of time to clinical worsening, WHO FC at 24 months, echocardiographic assessment of PH and quantitative assessment of right ventricular function, 6-min walk distance, and NT-proBNP levels. Exploratory endpoints include selected biomarkers, actigraphy, and assessments of quality of life. This study is designed to pave the way for additional clinical trials by establishing a robust infrastructure through the development of a PPHNet Clinical Trials Network.

Patterns of early life somatic growth in infants and children with a history of chronic lung disease of prematurity

OBJECTIVE

Preterm infants, and especially those with additional comorbidities, are at risk of early life growth failure, which may impact postnatal lung growth and attainment of peak lung function. However, little is known about the early life growth patterns of those with chronic lung disease. The goal of this study was to describe the patterns appreciated in this population and their association with certain clinical characteristics.

STUDY DESIGN

Demographic, clinical characteristics, and somatic growth parameters between birth and 3 years were retrospectively reviewed for a cohort of children (n = 616) recruited from an outpatient pulmonary clinic. Group-based trajectory modeling was used to identify unique longitudinal trajectories for each growth parameter. Demographic and clinical characteristics were compared using nonparametric analysis.

RESULTS

Four distinct trajectories were appreciated in all three somatic growth domains (weight, length, and weight-for-length), which demonstrated a sizable proportion of subjects with a z-score below zero at 36 months of age, suggesting that the traditional preterm paradigm of "catch-up" growth may not be accurate for this population.

CONCLUSIONS

Children with a history of chronic lung disease begin life with somatic growth measurements well below their term peers and display heterogeneous patterns of weight and length growth through the first 3 years of life. Future studies should focus on further understanding the relationship between somatic growth and respiratory outcomes in this population, which will ideally allow for the use of somatic growth measures as surrogate markers to identify individuals at the highest risk of postnatal growth failure and poor respiratory outcomes.

Association of Pseudomonas aeruginosa infection stage with lung function trajectory in children with cystic fibrosis

BACKGROUND

Pseudomonas aeruginosa (Pa) infection in cystic fibrosis (CF) is characterized in stages: never (prior to first positive culture) to incident (first positive culture) to chronic. The association of Pa infection stage with lung function trajectory is poorly understood and the impact of age on this association has not been examined. We hypothesized that FEV1 decline would be slowest prior to Pa infection, intermediate after incident infection and greatest after chronic Pa infection.

METHODS

Participants in a large US prospective cohort study diagnosed with CF prior to age 3 contributed data through the U.S. CF Patient Registry. Cubic spline linear mixed effects models were used to evaluate the longitudinal association of Pa stage (never, incident, chronic using 4 different definitions) with FEV1 adjusted for relevant covariates. Models contained interaction terms between age and Pa stage.

RESULTS

1,264 subjects born 1992-2006 provided a median 9.5 (IQR 0.25 to 15.75) years of follow up through 2017. 89% developed incident Pa; 39-58% developed chronic Pa depending on the definition. Compared to never Pa, incident Pa infection was associated with greater annual FEV1 decline and chronic Pa infection with the greatest FEV1 decline. The most rapid FEV1 decline and strongest association with Pa infection stage was seen in early adolescence (ages 12-15).

CONCLUSIONS

Annual FEV1 decline worsens significantly with each Pa infection stage in children with CF. Our findings suggest that measures to prevent chronic infection, particularly during the high-risk period of early adolescence, could mitigate FEV1 decline and improve survival.

Sex-Specific Differences in Congenital Diaphragmatic Hernia Mortality

OBJECTIVE

To compare disease severity and mortality differences between female and male patients with congenital diaphragmatic hernia (CDH).

STUDY DESIGN

We queried the CDH Study Group (CDHSG) database for CDH neonates managed between 2007 and 2018. Female and males were compared in statistical analyses using t tests, χ² tests, and Cox regression, as appropriate (P ≤ .05).

RESULTS

There were 7288 CDH patients, of which 3048 (41.8%) were female. Females weighed less on average at birth than males (2.84 kg vs 2.97 kg, P < .001) despite comparable gestational age. Females had similar rates of extracorporeal life support (ECLS) utilization (27.8% vs 27.3%, P = .65). Although both cohorts had equivalent defect size and rates of patch repair, female patients had increased rates of intrathoracic liver herniation (49.2% vs 45.9%, P = .01) and pulmonary hypertension (PH) (86.6% vs 81.1%, P < .001). Females had lower survival rates at 30-days (77.3% vs 80.1%, P = .003) and overall lower survival to discharge (70.2% vs 74.2%, P < .001). Subgroup analysis revealed that increased mortality was significant among those who underwent repair but were never supported on ECLS (P = .005). On Cox regression analysis, female sex was independently associated with mortality (adjusted hazard ratio 1.32, P = .02).

CONCLUSION

After controlling for the established prenatal and postnatal predictors of mortality, female sex remains independently associated with a higher risk of mortality in CDH. Further study into the underlying causes for sex-specific disparities in CDH outcomes is warranted.

Classifying multicenter approaches to invasive mechanical ventilation for infants with bronchopulmonary dysplasia using hierarchical clustering analysis

INTRODUCTION

Evidence-based ventilation strategies for infants with severe bronchopulmonary dysplasia (BPD) remain unknown. Determining whether contemporary ventilation approaches cluster as specific BPD strategies may better characterize care and enhance the design of clinical trials. The objective of this study was to test the hypothesis that unsupervised, multifactorial clustering analysis of point prevalence ventilator setting data would classify a discrete number of physiology-based approaches to mechanical ventilation in a multicenter cohort of infants with severe BPD.

METHODS

We performed a secondary analysis of a multicenter point prevalence study of infants with severe BPD treated with invasive mechanical ventilation. We clustered the cohort by mean airway pressure (MAP), positive end expiratory pressure (PEEP), set respiratory rate, and inspiratory time (Ti) using Ward's hierarchical clustering analysis (HCA).

RESULTS

Seventy-eight patients with severe BPD were included from 14 centers. HCA classified three discrete clusters as determined by an agglomerative coefficient of 0.97. Cluster stability was relatively strong as determined by Jaccard coefficient means of 0.79, 0.85, and 0.77 for clusters 1, 2, and 3, respectively. The median PEEP, MAP, rate, Ti, and PIP differed significantly between clusters for each comparison by Kruskall-Wallis testing (p < 0.0001).

CONCLUSIONS

In this study, unsupervised clustering analysis of ventilator setting data identified three discrete approaches to mechanical ventilation in a multicenter cohort of infants with severe BPD. Prospective trials are needed to determine whether these approaches to mechanical ventilation are associated with specific severe BPD clinical phenotypes and differentially modify respiratory outcomes.

Lung function and secondhand smoke exposure among children with cystic fibrosis: A Bayesian meta-analysis

BACKGROUND

Secondhand smoke exposure, an important environmental health factor in cystic fibrosis (CF), remains uniquely challenging to children with CF as they strive to maintain pulmonary function during early stages of growth and throughout adolescence. Despite various epidemiologic studies among CF populations, little has been done to coalesce estimates of the association between secondhand smoke exposure and lung function decline.

METHODS

A systematic review was performed using PRISMA guidelines. A Bayesian random-effects model was employed to estimate the association between secondhand smoke exposure and change in lung function (measured as FEV1% predicted).

RESULTS

Quantitative synthesis of study estimates indicated that second-hand smoke exposure corresponded to a significant drop in FEV1 (estimated decrease: -5.11% predicted; 95% CI: -7.20, -3.47). The estimate of between-study heterogeneity was 1.32% predicted (95% CI: 0.05, 4.26). There was moderate heterogeneity between the 6 analyzed studies that met review criteria (degree of heterogeneity: I2=61.9% [95% CI: 7.3-84.4%] and p = 0.022 from the frequentist method.) CONCLUSIONS: Our results quantify the impact at the pediatric population level and corroborate the assertion that secondhand smoke exposure negatively affects pulmonary function in children with CF. Findings highlight challenges and opportunities for future environmental health interventions in pediatric CF care.

Genetic Modifiers of Cystic Fibrosis Lung Disease Severity: Whole-Genome Analysis of 7,840 Patients

Rationale: Lung disease is the major cause of morbidity and mortality in persons with cystic fibrosis (pwCF). Variability in CF lung disease has substantial non-CFTR (CF transmembrane conductance regulator) genetic influence. Identification of genetic modifiers has prognostic and therapeutic importance. Objectives: Identify genetic modifier loci and genes/pathways associated with pulmonary disease severity. Methods: Whole-genome sequencing data on 4,248 unique pwCF with pancreatic insufficiency and lung function measures were combined with imputed genotypes from an additional 3,592 patients with pancreatic insufficiency from the United States, Canada, and France. This report describes association of approximately 15.9 million SNPs using the quantitative Kulich normal residual mortality-adjusted (KNoRMA) lung disease phenotype in 7,840 pwCF using premodulator lung function data. Measurements and Main Results: Testing included common and rare SNPs, transcriptome-wide association, gene-level, and pathway analyses. Pathway analyses identified novel associations with genes that have key roles in organ development, and we hypothesize that these genes may relate to dysanapsis and/or variability in lung repair. Results confirmed and extended previous genome-wide association study findings. These whole-genome sequencing data provide finely mapped genetic information to support mechanistic studies. No novel primary associations with common single variants or rare variants were found. Multilocus effects at chr5p13 (SLC9A3/CEP72) and chr11p13 (EHF/APIP) were identified. Variant effect size estimates at associated loci were consistently ordered across the cohorts, indicating possible age or birth cohort effects. Conclusions: This premodulator genomic, transcriptomic, and pathway association study of 7,840 pwCF will facilitate mechanistic and postmodulator genetic studies and the development of novel therapeutics for CF lung disease.

Validation of an outpatient questionnaire for bronchopulmonary dysplasia control

INTRODUCTION

Despite bronchopulmonary dysplasia (BPD) being a common morbidity of preterm birth, there is no validated objective tool to assess outpatient respiratory symptom control for clinical and research purposes.

METHODS

Data were obtained from 1049 preterm infants and children seen in outpatient BPD clinics of 13 US tertiary care centers from 2018 to 2022. A new standardized instrument was modified from an asthma control test questionnaire and administered at the time of clinic visits. External measures of acute care use were also collected. The questionnaire for BPD control was validated in the entire population and selected subgroups using standard methodology for internal reliability, construct validity, and discriminative properties.

RESULTS

Based on the scores from BPD control questionnaire, the majority of caregivers (86.2%) felt their child's symptoms were under control, which did not differ by BPD severity (p = 0.30) or a history of pulmonary hypertension (p = 0.42). Across the entire population and selected subgroups, the BPD control questionnaire was internally reliable, suggestive of construct validity (albeit correlation coefficients were -0.2 to -0.4.), and discriminated control well. Control categories (controlled, partially controlled, and uncontrolled) were also predictive of sick visits, emergency department visits, and hospital readmissions.

CONCLUSION

Our study provides a tool for assessing respiratory control in children with BPD for clinical care and research studies. Further work is needed to identify modifiable predictors of disease control and link scores from the BPD control questionnaire to other measures of respiratory health such as lung function testing.

Outpatient respiratory outcomes in children with BPD on supplemental oxygen

INTRODUCTION

Preterm children with bronchopulmonary dysplasia (BPD) frequently require supplemental oxygen in the outpatient setting. In this study, we sought to determine patient characteristics and demographics associated with need for supplemental oxygen at initial hospital discharge, timing to supplemental oxygen liberation, and associations between level of supplemental oxygen and likelihood of respiratory symptoms and acute care usage in the outpatient setting.

METHODS

A retrospective analysis of subjects with BPD on supplemental oxygen (O2 ) was performed. Subjects were recruited from outpatient clinics at Johns Hopkins University and the Children's Hospital of Philadelphia between 2008 and 2021. Data were obtained by chart review and caregiver questionnaires.

RESULTS

Children with BPD receiving ≥1 L of O2 were more likely to have severe BPD, pulmonary hypertension, and be older at initial hospital discharge. Children discharged on higher levels of supplemental O2 were slower to wean to room air compared to lower O2 groups (p < 0.001). Additionally, weaning off supplemental O2 in the outpatient setting was delayed in children with gastrostomy tubes and those prescribed inhaled corticosteroids, on public insurance or with lower household incomes. Level of supplemental O2 at discharge did not influence outpatient acute care usage or respiratory symptoms.

CONCLUSION

BPD severity and level of supplemental oxygen use at discharge did not correlate with subsequent acute care usage or respiratory symptoms in children with BPD. Weaning of O2 however was significantly associated with socioeconomic status and respiratory medication use, contributing to the variability in O2 weaning in the outpatient setting.

Respiratory Outcomes for Ventilator-Dependent Children With Bronchopulmonary Dysplasia

OBJECTIVES

To describe outpatient respiratory outcomes and center-level variability among children with severe bronchopulmonary dysplasia (BPD) who require tracheostomy and long-term mechanical ventilation.

METHODS

Retrospective cohort of subjects with severe BPD, born between 2016 and 2021, who received tracheostomy and were discharged on home ventilator support from 12 tertiary care centers participating in the BPD Collaborative Outpatient Registry. Timing of key respiratory events including time to tracheostomy placement, initial hospital discharge, first outpatient clinic visit, liberation from the ventilator, and decannulation were assessed using Kaplan-Meier analysis. Differences between centers for the timing of events were assessed via log-rank tests.

RESULTS

There were 155 patients who met inclusion criteria. Median age at the time of the study was 32 months. The median age of tracheostomy placement was 5 months (48 weeks' postmenstrual age). The median ages of hospital discharge and first respiratory clinic visit were 10 months and 11 months of age, respectively. During the study period, 64% of the subjects were liberated from the ventilator at a median age of 27 months and 32% were decannulated at a median age of 49 months. The median ages for all key events differed significantly by center (P ≤ .001 for all events).

CONCLUSIONS

There is wide variability in the outpatient respiratory outcomes of ventilator-dependent infants and children with severe BPD. Further studies are needed to identify the factors that contribute to variability in practice among the different BPD outpatient centers, which may include inpatient practices.

Early life growth trajectories in cystic fibrosis are associated with lung function at age six

BACKGROUND

Higher growth percentiles are associated with more favorable lung function in cystic fibrosis (CF), prompting the creation of CF Foundation (CFF) nutritional guidelines.

OBJECTIVES

To describe early childhood growth trajectories within CF, to determine if growth trajectories are associated with differences in lung function at age six, and to identify factors that differ between trajectory groups.

METHODS

Retrospective cohort study of children diagnosed with CF and born 2000-2011 using the US CFF Patient Registry. Annualized growth parameters prior to age six were included in group-based trajectory modeling to identify unique early life growth trajectories. FEV1 percent predicted (FEV1pp) at age six was compared between trajectory groups using linear regression. Factors associated with group membership were identified using multinomial logistic regression.

RESULTS

6,809 children met inclusion criteria. Six discrete growth trajectories were identified, including three groups that began with growth parameters >50th percentile, termed: "always high", "gradual decliner", "rapid decliner", and three which began with growth parameters <50th percentile, termed: "rapid riser", "gradual riser", "always low". FEV1pp at age six was highest for the Always High trajectory. The Always Low trajectory was nearly 10% lower than the Always High trajectory. Sex, ethnicity, newborn screening and pancreatic function were associated with trajectory class membership.

CONCLUSIONS

Distinct early life growth trajectories were identified within CF. Trajectories that met CFF nutritional guideline recommendations were associated with higher FEV1pp at age six. CF care teams should continue to partner with families to encourage interventions to support optimal growth to improve lung function in CF.

Racial and Ethnic Disparities in Outcomes Among Newborns with Congenital Diaphragmatic Hernia

Importance

There is some data to suggest that racial and ethnic minority infants with congenital diaphragmatic hernia (CDH) have poorer clinical outcomes.

Objective

To determine what patient- and institutional-level factors are associated with racial and ethnic differences in CDH mortality.

Design, Setting, and Participants

Multicenter cohort study of 49 US children's hospitals using the Pediatric Health Information System database from January 1, 2015, to December 31, 2020. Participants were patients with CDH admitted on day of life 0 who underwent surgical repair. Patient race and ethnicity were guardian-reported vs hospital assigned as Black, Hispanic (White or Black), or White. Data were analyzed from August 2021 to March 2022.

Exposures

Patient race and ethnicity: (1) White vs Black and (2) White vs Hispanic; and institutional-level diversity (as defined by the percentage of Black and Hispanic patients with CDH at each hospital): (1) 30% or less, (2) 31% to 40%, and (3) more than 40%.

Main Outcomes and Measures

The primary outcomes were in-hospital and 60-day mortality. The study hypothesized that hospitals managing a more racially and ethnically diverse population of patients with CDH would be associated with lower mortality among Black and Hispanic infants.

Results

Among 1565 infants, 188 (12%), 306 (20%), and 1071 (68%) were Black, Hispanic, and White, respectively. Compared with White infants, Black infants had significantly lower gestational ages (mean [SD], White: 37.6 [2] weeks vs Black: 36.6 [3] weeks; difference, 1 week; 95% CI for difference, 0.6-1.4; P < .001), lower birthweights (White: 3.0 [1.0] kg vs Black: 2.7 [1.0] kg; difference, 0.3 kg; 95% CI for difference, 0.2-0.4; P < .001), and higher extracorporeal life support use (White: 316 patients [30%] vs Black: 69 patients [37%]; χ21 = 3.9; P = .05). Black infants had higher 60-day (White: 99 patients [9%] vs Black: 29 patients [15%]; χ21 = 6.7; P = .01) and in-hospital (White: 133 patients [12%] vs Black: 40 patients [21%]; χ21 = 10.6; P = .001) mortality . There were no mortality differences in Hispanic patients compared with White patients. On regression analyses, institutional diversity of 31% to 40% in Black patients (hazard ratio [HR], 0.17; 95% CI, 0.04-0.78; P = .02) and diversity greater than 40% in Hispanic patients (HR, 0.37; 95% CI, 0.15-0.89; P = .03) were associated with lower mortality without altering outcomes in White patients.

Conclusions and Relevance

In this cohort study of 1565 who underwent surgical repair patients with CDH, Black infants had higher 60-day and in-hospital mortality after adjusting for disease severity. Hospitals treating a more racially and ethnically diverse patient population were associated with lower mortality in Black and Hispanic patients.

Approaches to Interdisciplinary Care for Infants with Severe Bronchopulmonary Dysplasia: A Survey of the Bronchopulmonary Dysplasia Collaborative

OBJECTIVE

 Bronchopulmonary dysplasia (BPD) remains the most common late morbidity for extremely premature infants. Care of infants with BPD requires a longitudinal approach from the neonatal intensive care unit to ambulatory care though interdisciplinary programs. Current approaches for the development of optimal programs vary among centers.

STUDY DESIGN

 We conducted a survey of 18 academic centers that are members of the BPD Collaborative, a consortium of institutions with an established interdisciplinary BPD program. We aimed to characterize the approach, composition, and current practices of the interdisciplinary teams in inpatient and outpatient domains.

RESULTS

 Variations exist among centers, including composition of the interdisciplinary team, whether the team is the primary or consult service, timing of the first team assessment of the patient, frequency and nature of rounds during the hospitalization, and the timing of ambulatory visits postdischarge.

CONCLUSION

 Further studies to assess long-term outcomes are needed to optimize interdisciplinary care of infants with severe BPD.

KEY POINTS

· Care of infants with BPD requires a longitudinal approach from the NICU to ambulatory care.. · Benefits of interdisciplinary care for children have been observed in other chronic conditions.. · Current approaches for the development of optimal interdisciplinary BPD programs vary among centers..

Clinical outcomes in cystic fibrosis at 6 years of age with tricare insurance coverage

Health insurance coverage is associated with outcomes in cystic fibrosis (CF). A fraction of individuals in the United States are covered through Tricare, a federally funded program for military members and their dependents. The role of Tricare on CF health outcomes is unknown. Using a retrospective CF Foundation Patient Registry cohort born 2000-2011, insurance status was defined as any Tricare (n = 328) with reference groups of always private (n = 3,455) and exclusively public (n = 2,669) during the first 6 years of life. Subjects with Tricare coverage attended more CF care centers and lived in more zip codes by age 6 than their counterparts. BMI did not differ between groups. Subjects with Tricare had a higher FEV1 at age 6 compared to those with always public insurance. Overall, outcomes for those with Tricare insurance appeared more similar to those with always private insurance. Future research should consider treating Tricare coverage similar to private insurance.

Daycare Attendance is Linked to Increased Risk of Respiratory Morbidities in Children Born Preterm with Bronchopulmonary Dysplasia

OBJECTIVES

To test the hypothesis that daycare attendance among children with bronchopulmonary dysplasia (BPD) is associated with increased chronic respiratory symptoms and/or greater health care use for respiratory illnesses during the first 3 years of life.

STUDY DESIGN

Daycare attendance and clinical outcomes were obtained via standardized instruments for 341 subjects recruited from 9 BPD specialty clinics in the US. All subjects were former infants born preterm (<34 weeks) with BPD (71% severe) requiring outpatient follow-up between 0 and 3 years of age. Mixed logistic regression models were used to test for associations.

RESULTS

Children with BPD attending daycare were more likely to have emergency department visits and systemic steroid usage. Children in daycare up to 3 years of age also were more likely to report trouble breathing, having activity limitations, and using rescue medications when compared with children not in daycare. More severe manifestations were found in children attending daycare between 6 and 12 months of chronological age.

CONCLUSIONS

In this study, children born preterm with BPD who attend daycare were more likely to visit the emergency department, use systemic steroids, and have chronic respiratory symptoms compared with children not in daycare, indicating that daycare may be a potential modifiable risk factor to minimize respiratory morbidities in children with BPD during the preschool years.

Area deprivation and respiratory morbidities in children with bronchopulmonary dysplasia

INTRODUCTION

Infants and children diagnosed with bronchopulmonary dysplasia (BPD) have a higher likelihood of recurrent hospitalizations and asthma-like symptoms. Socio-environmental factors that influence the frequency and severity of pulmonary symptoms in these children during the preschool age are poorly understood. In this study, we used the Area Deprivation Index (ADI) to evaluate the relationship between the socio-environmental exposures in children with BPD and respiratory outcomes during the first few years of life.

METHODS

A registry of subjects recruited from outpatient BPD clinics at Johns Hopkins University (n = 909) and the Children's Hospital of Philadelphia (n = 125) between January 2008 and October 2021 was used. Subjects were separated into tertiles by ADI scores aggregated to ZIP codes. Caregiver questionnaires were used to assess the frequency of respiratory morbidities and acute care usage for respiratory symptoms.

RESULTS

The mean gestational age of subjects was 26.8 ± 2.6 weeks with a mean birthweight of 909 ± 404 g. The highest tertile (most deprived) of ADI was significantly associated with emergency department visits (aOR 1.72; p = 0.009), hospital readmissions (aOR 1.66; p = 0.030), and activity limitations (aOR 1.55; p = 0.048) compared to the lowest tertile. No association was seen with steroid, antibiotic or rescue medication use, trouble breathing, or nighttime symptoms.

CONCLUSION

In this study, children with BPD who lived in areas of higher deprivation were more likely to be rehospitalized and have ED visits for respiratory reasons. Identifying socio-environmental factors that contribute to adverse pulmonary outcomes in children with BPD may provide opportunities for earlier interventions to improve long-term pulmonary outcomes.

Perinatal Inflammatory Biomarkers and Respiratory Disease in Preterm Infants

OBJECTIVE

To measure plasma levels of vascular endothelial growth factor (VEGF) and several cytokines (Interleukin [IL]-6 IL-8, IL-10) during the first week of life to examine the relationship between protein expression and likelihood of developing respiratory distress syndrome (RDS) and bronchopulmonary dysplasia (BPD).

STUDY DESIGN

Levels of IL-6, IL-8, IL-10, and VEGF were measured from plasma obtained from preterm patients during the first week of life. Newborns were recruited from a single center between April 2009 and April 2019. Criteria for the study included being inborn, birth weight of less than 1500 grams, and a gestational age of less than 32 weeks at birth.

RESULTS

The development of RDS in preterm newborns was associated with lower levels of VEGF during the first week of life. Higher plasma levels of IL-6 and IL-8 plasma were associated with an increased likelihood and increased severity of BPD at 36 weeks postmenstrual age. In contrast, plasma levels of VEGF, IL-6, IL-8, and IL-10 obtained during the first week of life were not associated with respiratory symptoms and acute care use in young children with BPD in the outpatient setting.

CONCLUSIONS

During the first week of life, lower plasma levels of VEGF was associated with the diagnosis of RDS in preterm infants. Preterm infants with higher levels of IL-6 and IL-8 during the first week of life were also more likely to be diagnosed with BPD. These biomarkers may help to predict respiratory morbidities in preterm newborns during their initial hospitalization.

Insurance coverage and respiratory morbidities in bronchopulmonary dysplasia

INTRODUCTION

Preterm infants and young children with bronchopulmonary dysplasia (BPD) are at increased risk for acute care utilization and chronic respiratory symptoms during early life. Identifying risk factors for respiratory morbidities in the outpatient setting could decrease the burden of care. We hypothesized that public insurance coverage was associated with higher acute care usage and respiratory symptoms in preterm infants and children with BPD after initial neonatal intensive care unit (NICU) discharge.

METHODS

Subjects were recruited from BPD clinics at 10 tertiary care centers in the United States between 2018 and 2021. Demographics and clinical characteristics were obtained through chart review. Surveys for clinical outcomes were administered to caregivers.

RESULTS

Of the 470 subjects included in this study, 249 (53.0%) received employer-based insurance coverage and 221 (47.0%) received Medicaid as sole coverage at least once between 0 and 3 years of age. The Medicaid group was twice as likely to have sick visits (adjusted odd ratio [OR]: 2.06; p = 0.009) and emergency department visits (aOR: 2.09; p = 0.028), and three times more likely to be admitted for respiratory reasons (aOR: 3.04; p = 0.001) than those in the employer-based group. Additionally, those in the Medicaid group were more likely to have nighttime respiratory symptoms (aOR: 2.62; p = 0.004).

CONCLUSIONS

Children with BPD who received Medicaid coverage were more likely to utilize acute care and have nighttime respiratory symptoms during the first 3 years of life. More comprehensive studies are needed to determine whether the use of Medicaid represents a barrier to accessing care, lower socioeconomic status, and/or a proxy for detrimental environmental exposures.

Patterns and predictors of air purifier adherence in children with asthma living in low-income, urban households

OBJECTIVE

Black children and children from low-income communities are disproportionately affected by asthma, attributed partly to pollution exposure. Air purifiers reduce indoor air pollution and improve asthma symptoms in children. In order to implement air purifier interventions, an understanding of patterns of use and potential barriers is necessary.

METHODS

In a home intervention study, 127 children with asthma living in Baltimore were randomized to receive two active or two placebo air purifiers. The 16-week study period included: baseline clinic visit, home visit for air purifier installation (active or placebo) with instruction to use the high or turbo settings, and electronic adherence monitoring of air purifiers. Determinants of adherence were identified using linear regression models.

RESULTS

Air purifiers were used 80% of the time, and participants demonstrated adherence to high or turbo settings for 60% of the time. In an adjusted model, season was the major determinant of air purifier adherence, with 21% lower use in the winter (p = 0.025) attributed to the cold draft generated by the machine.

CONCLUSION

In a clinical trial with electronic adherence monitoring, air purifier use was high and participants were adherent to use of high or turbo settings the majority of the time. Addressing practical barriers to consistent use, such as draft during the winter, in addition to financial barriers may improve air purifier adherence among children with asthma living in low-income, urban households.

CLINICAL TRIALS REGISTRY NUMBER

NCT02763917.

Developmental Effects of Electronic Cigarette Use

Electronic cigarettes have gained widespread acceptance among adolescents and young adults. As a result of this popularity, there are concerns regarding the potential harm of primary, secondhand and thirdhand electronic cigarette exposures on fetal and postnatal development. In vitro studies have shown that constituents in electronic cigarette liquids, including nicotine, flavorings, and carrier agents can alter cellular processes and growth. Additionally, aerosolized electronic cigarette emissions have been shown to disrupt organ development and immune responses in preclinical studies. In clinical studies, an association between electronic cigarette use and frequent respiratory symptoms, greater asthma severity and impaired mucociliary clearance has been demonstrated with adolescent and young adult users of electronic cigarettes having twice the frequency of cough, mucus production, or bronchitis compared to nonusers. Along with the popularity of electronic cigarette use, secondhand electronic cigarette exposure has increased substantially; with almost one-fourth of middle and high school children reporting exposure to secondhand vapors. The health consequences of secondhand electronic cigarette exposure on children and other vulnerable populations are poorly understood but detectable levels of cotinine have been measured in nonusers. Pregnant women and their offspring are another vulnerable group at increased risk for health consequences from electronic cigarette exposure. Nicotine crosses the placenta and can disrupt brain and lung development in preclinical studies. This article will focus on the physiological and health effects associated with primary or secondhand exposure to electronic cigarettes. It is expected that with ongoing availability of electronic cigarettes as well as the accumulation of additional follow-up time for long-term outcomes, the risks associated with exposure will become better clarified. © 2022 American Physiological Society. Compr Physiol 12:3337-3346, 2022.

Ventilatory Strategies in Infants with Established Severe Bronchopulmonary Dysplasia: A Multicenter Point Prevalence Study

We performed a point prevalence study on infants with severe bronchopulmonary dysplasia (BPD), collecting data on type and settings of ventilatory support; 187 infants, 51% of whom were on invasive positive-pressure ventilation (IPPV), from 15 centers were included. We found a significant center-specific variation in ventilator modes.

Indoor air pollution exposure is associated with greater morbidity in cystic fibrosis

BACKGROUND

Exposure to higher levels of outdoor air pollution is associated with increased morbidity in individuals with cystic fibrosis. Limited information exist regarding the potential adverse effects of indoor air pollution on those with cystic fibrosis.

METHODS

Individuals with cystic fibrosis who were enrolled in the Twin and Sibling Study from 2000-2013, self-reported exposure to four known sources of indoor air pollution (secondhand smoke, forced hot air, wood stove and fireplace). Change in lung function, rates of hospitalizations and pulmonary exacerbations were followed over 4 years to compare outcomes in those who were exposed to those who were not exposed.

RESULTS

Of 1432 participants with data on secondhand smoke exposure, 362 (25.3%) were exposed. Of 765 individuals with data on forced hot air exposure, 491 (64.2%) were exposed. Of 1247 participants with data on wood stove exposure and 830 with data on fireplace exposure, 182 (14.6%) and 373 (44.9%) were exposed, respectively. In longitudinal analysis, pediatric individuals either exposed to secondhand smoke or to forced hot air had a 0.60% predicted/year decrease in FEV₁% predicted (P=0.002) or a 0.46% predicted/year decrease in FEV1% predicted (P=0.048), respectively compared to individuals who were not exposed. Adults exposed to secondhand smoke had a 42% increased yearly risk of hospitalization compared to those who were not exposed (P=0.045).

CONCLUSIONS

Our questionnaire-based data suggest that exposure to sources of indoor air pollution increase morbidity in both the pediatric and adult cystic fibrosis populations. Future studies with quantitative indoor air quality assessments are needed.

Mortality in Outpatients with Bronchopulmonary Dysplasia

OBJECTIVES

To study the demographic and clinical characteristics of preterm infants with bronchopulmonary dysplasia (BPD) to identify the factors most strongly predictive of outpatient mortality, with the goal of identifying those individuals at greatest risk.

STUDY DESIGN

Demographic and clinical characteristics were retrospectively reviewed for 862 subjects recruited from an outpatient BPD clinic. Characteristics of the deceased and living participants were compared using nonparametric analysis. Regression analysis was performed to identify factors associated with mortality.

RESULTS

Of the 862 subjects, 13 (1.5%) died during follow-up, for an overall mortality rate of approximately 15.1 deaths per 1000 subjects. Two patients died in the postneonatal period (annual mortality incidence, 369.9 per 100 000), 9 died between age 1 and 4 years (annual mortality incidence, 310.2 per 100 000), and 2 died between age of 5 and 14 years (annual mortality incidence, 71.4 per 100 000). After adjusting for gestational age and BPD severity, mortality was found to be associated with the amount of supplemental oxygen required at discharge from the neonatal intensive care unit (adjusted hazard ratio [aHR], 4.10; P = .001), presence of a gastrostomy tube (aHR, 8.13; P = .012), and presence of a cerebrospinal fluid (CSF) shunt (aHR, 4.31; P = .021).

CONCLUSIONS

The incidence of mortality among preterm infants with BPD is substantially higher than that seen in the general population. The need for greater amounts of home supplemental oxygen and the presence of a gastrostomy tube or CSF shunt were associated with an increased risk of postdischarge mortality. Future studies should focus on clarifying risk factors for the development of severe disease to allow for early identification and treatment of those at highest risk.

Association between insurance variability and early lung function in children with cystic fibrosis

BACKGROUND

Lower socioeconomic status (SES) has consistently been associated with poorer outcomes in individuals with cystic fibrosis (CF). Previous studies have compared outcomes for children with and without private insurance coverage, however the potential role of changes in insurance status on early health outcomes in children with CF remains unknown.

OBJECTIVES

To describe the variability in insurance status in early childhood and to evaluate whether insurance variability was associated with poorer outcomes at age 6.

METHODS

Retrospective observational study using the Cystic Fibrosis Foundation Patient Registry. Insurance status was defined as: always private (including Tricare), exclusively public, or intermittent private insurance (private insurance and exclusively public insurance in separate years) during the first 6 years of life. Outcomes at age 6 included body mass index (BMI) and FEV₁ percent predicted (maxFEV₁pp).

RESULTS

From a 2000-2011 birth cohort (n = 8,109), 42.3% always had private insurance, 30.0% had exclusively public insurance, and 27.6% had intermittent private insurance. BMI percentiles did not differ between groups; however, children with intermittent private insurance and exclusively public insurance had a 3.3% and 6.6% lower maxFEV₁pp at age 6, respectively, compared to those with always private insurance.

CONCLUSIONS

A substantial proportion of young children in a modern CF cohort have public or intermittent private insurance coverage. While public insurance has been associated with poorer health outcomes in CF, variability in health insurance coverage may also be associated with an intermediate risk of disparities in lung function as early as age 6.

Outpatient Respiratory Management of Infants, Children, and Adolescents with Post-Prematurity Respiratory Disease: An Official American Thoracic Society Clinical Practice Guideline

Background: Premature birth affects millions of neonates each year, placing them at risk for respiratory disease due to prematurity. Bronchopulmonary dysplasia is the most common chronic lung disease of infancy, but recent data suggest that even premature infants who do not meet the strict definition of bronchopulmonary dysplasia can develop adverse pulmonary outcomes later in life. This post-prematurity respiratory disease (PPRD) manifests as chronic respiratory symptoms, including cough, recurrent wheezing, exercise limitation, and reduced pulmonary function. This document provides an evidence-based clinical practice guideline on the outpatient management of infants, children, and adolescents with PPRD. Methods: A multidisciplinary panel of experts posed questions regarding the outpatient management of PPRD. We conducted a systematic review of the relevant literature. The Grading of Recommendations, Assessment, Development, and Evaluation approach was used to rate the quality of evidence and the strength of the clinical 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 were developed for or against three common medical therapies and four diagnostic evaluations in the context of the outpatient management of PPRD. Conclusions: The panel developed recommendations for the outpatient management of patients with PPRD on the basis of limited evidence and expert opinion. Important areas for future research were identified.

Protracted respiratory findings in children post-SARS-CoV-2 infection

INTRODUCTION

Although prolonged respiratory symptoms following severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection have been described in adults, data are emerging that children also experience long-term sequelae of coronavirus disease 2019 (COVID-19). The respiratory sequelae of COVID-19 in children remain poorly characterized. In this study we describe health data and respiratory findings in pediatric patients presenting with persistent respiratory symptoms following COVID-19.

METHODS

This study included patients referred to Pulmonary Clinic at the Children's Hospital of Philadelphia between December 2020 and April 2021 (n = 29). Inclusion criteria included a history of SARS-CoV-2 RNA positivity or confirmed close household contact and suggestive symptoms. A retrospective chart review was performed and demographic, clinical, imaging, and functional test data were collected.

RESULTS

The mean age at presentation to clinic was 13.1 years (range: 4-19 years). Patients had persistent respiratory symptoms ranging from 1.3 to 6.7 months postacute infection. Persistent dyspnea and/or exertional dyspnea were present in nearly all (96.6%) patients at the time of clinic presentation. Other reported chronic symptoms included cough (51.7%) and exercise intolerance (48.3%). Fatigue was reported in 13.8% of subjects. Many subjects were overweight or obese (62.1%) and 11 subjects (37.9%) had a prior history of asthma. Spirometry and plethysmography were normal in most patients. The six-minute walk test (6MWT) revealed exercise intolerance and significant tachycardia in two-thirds of the nine children tested.

CONCLUSION

Exertional dyspnea, cough and exercise intolerance were the most common respiratory symptoms in children with postacute COVID-19 respiratory symptoms seen in an outpatient pulmonary clinic. Spirometry (and plethysmography when available), however, was mostly normal, and exertional intolerance was frequently demonstrated using the 6MWT.

Accurate assignment of disease liability to genetic variants using only population data

PURPOSE

The growing size of public variant repositories prompted us to test the accuracy of pathogenicity prediction of DNA variants using population data alone.

METHODS

Under the a priori assumption that the ratio of the prevalence of variants in healthy population vs that in affected populations form 2 distinct distributions (pathogenic and benign), we used a Bayesian method to assign probability to a variant belonging to either distribution.

RESULTS

The approach, termed Bayesian prevalence ratio (BayPR), accurately parsed 300 of 313 expertly curated CFTR variants: 284 of 296 pathogenic/likely pathogenic variants in 1 distribution and 16 of 17 benign/likely benign variants in another. BayPR produced an area under the receiver operating characteristic curve of 0.99 for 103 functionally confirmed missense CFTR variants, which is equal to or exceeds 10 commonly used algorithms (area under the receiver operating characteristic curve range = 0.54-0.99). Application of BayPR to expertly curated variants in 8 genes associated with 7 Mendelian conditions led to the assignment of a disease-causing probability of ≥80% to 1350 of 1374 (98.3%) pathogenic/likely pathogenic variants and of ≤20% to 22 of 23 (95.7%) benign/likely benign variants.

CONCLUSION

Irrespective of the variant type or functional effect, the BayPR approach provides probabilities of pathogenicity for DNA variants responsible for Mendelian disorders using only the variant counts in affected and unaffected population samples.

Bronchopulmonary dysplasia as a determinant of respiratory outcomes in adult life

Respiratory disease is unfortunately common in preterm infants with the archetype being bronchopulmonary dysplasia (BPD). BPD affects approximately 50,000 preterm infants in the U.S. annually with substantial morbidity and mortality related to its pathology (alveolar, airway, and pulmonary vasculature maldevelopment). Predicting the likelihood and severity of chronic respiratory disease in these children as they age is difficult and compounded by the lack of consistent phenotyping. Barriers to understanding the actual scope of this problem include few longitudinal studies, information limited by small retrospective studies and the ever-changing landscape of therapies in the NICU that affect long-term respiratory outcomes. Thus, the true burden of adult respiratory disease caused by premature birth is currently unknown. Nevertheless, limited data suggest that a substantial percentage of children with a history of BPD have long-term respiratory symptoms and persistent airflow obstruction associated with altered lung function trajectories into adult life. Small airway disease with variable bronchodilator responsiveness, is the most common manifestation of lung dysfunction in adults with a history of BPD. The etiology of this is unclear however, developmental dysanapsis may underlie the airflow obstruction in some adults with a history of BPD. This type of flow limitation resembles that of aging adults with chronic obstructive lung disease with no history of smoking. It is also unclear whether lung function abnormalities in people with a history of BPD are static or if these individuals with BPD have a more accelerated decline in lung function as they age compared to controls. While some of the more significant mediators of lung function, such as tobacco smoke and respiratory infections have been identified, more work is necessary to identify the best means of preserving lung function for individuals born prematurely throughout their lifespan.

Family history of asthma influences outpatient respiratory outcomes in children with BPD

INTRODUCTION

Preterm children with bronchopulmonary dysplasia (BPD) are at increased risk for intermittent and chronic respiratory symptoms during childhood and adult life. Identifying children at higher risk for respiratory morbidities in the outpatient setting could help improve long-term outcomes. In this study, we hypothesized that a family history of asthma (FHA) is a risk factor for higher acute care usage and respiratory symptoms in preterm infants/children with BPD, following initial discharge home.

METHODS

Subjects were recruited from the Johns Hopkins Bronchopulmonary Dysplasia outpatient clinic between January 2008 and February 2020 (n = 827). Surveys were administered to caregivers and demographics and clinical characteristics were obtained through chart review.

RESULTS

Demographic features associated with FHA included public health insurance, lower median household income, and nonwhite race. Children with FHA had higher odds of emergency department (ED) visits, systemic steroid use, nighttime respiratory symptoms, and activity limitations. There was no association between FHA and BPD severity.

CONCLUSION

This study found that children with BPD and FHA were more likely to have respiratory symptoms and acute care usage during the first 3 years of life and that FHA was associated with lower socioeconomic status. Although there was no association between FHA and BPD severity, FHA could predict an increased likelihood of both ED visits and need for systemic steroids in infants/children with BPD followed in the outpatient setting.

Influences of environmental exposures on preterm lung disease

Introduction: Environmental factors play a critical role in the progression or resolution of chronic respiratory diseases. However, studies are limited on the impact of environmental risk factors on individuals born prematurely with lung disease after they leave the neonatal intensive care unit and are discharged into the home environment.Areas covered: In this review, we cover current knowledge of environmental exposures that impact outcomes of preterm respiratory disease, including air pollution, infections, and disparities. The limited data do suggest that certain exposures should be avoided and there are potential preventative strategies for other exposures. There is a need for additional research outside the neonatal intensive care unit that focuses on individual and community-level factors that affect long-term outcomes.Expert opinion: Preterm respiratory disease can impose a significant burden on infants, children, and young adults born prematurely, but may improve for many individuals over time. In this review, we outline the exposures that may potentially hasten, delay, or prevent resolution of lung injury in preterm children.

Comparing encounter-based and annualized chronic pseudomonas infection definitions in cystic fibrosis

Chronic Pseudomonas aeruginosa (Pa) infection is associated with increased morbidity and mortality in people with cystic fibrosis (CF). There is no gold standard definition of chronic Pa infection in CF. We compared chronic Pa definitions using encounter-based versus annualized data in the Early Pseudomonas Infection Control (EPIC) Observational study cohort, and subsequently compared annualized chronic Pa definitions across a range of U.S. cohorts spanning decades of CF care. We found that an annualized chronic Pa definition requiring at least 1 Pa+ culture in 3 of 4 consecutive years ("Green 3/4") resulted in chronic Pa metrics similar to established encounter-based modified Leeds criteria definitions, including a similar age at and proportion who fulfilled chronic Pa criteria, and a similar proportion with sustained Pa infection after meeting the chronic Pa definition. The Green 3/4 chronic Pa definition will be valuable for longitudinal analyses in cohorts with limited culture frequency.

Characteristics of infants or children presenting to outpatient bronchopulmonary dysplasia clinics in the United States

INTRODUCTION

Bronchopulmonary dysplasia (BPD) is a common respiratory sequelae of preterm birth, for which longitudinal outpatient data are limited. Our objective was to describe a geographically diverse outpatient cohort of former preterm infants followed in BPD-disease specific clinics.

METHODS

Seven BPD specialty clinics contributed data using standardized instruments to this retrospective cohort study. Inclusion criteria included preterm birth (<37 weeks) and respiratory symptoms or needs requiring outpatient follow-up.

RESULTS

A total of 413 preterm infants and children were recruited (mean age: 2.4 ± 2.7 years) with a mean gestational age of 27.0 ± 2.8 weeks and a mean birthweight of 951 ± 429 grams of whom 63.7% had severe BPD. Total, 51.1% of subjects were nonwhite. Severe BPD was not associated with greater utilization of acute care/therapies compared to non-severe counterparts. Of children with severe BPD, differences in percentage of those on any home respiratory support (p = .001), home positive pressure ventilation (p = .003), diuretics (p < .001), inhaled corticosteroids (p < .001), and pulmonary vasodilators (p < .001) were found between centers, however no differences in acute care use were observed.

DISCUSSION

This examination of a multicenter collaborative registry of children born prematurely with respiratory disease demonstrates a diversity of management strategies among geographically distinct tertiary care BPD centers in the United States. This study reveals that the majority of children followed in these clinics were nonwhite and that neither variation in management nor severity of BPD at 36 weeks influenced outpatient acute care utilization. These findings suggest that post-neonatal intensive care unit factors and follow-up may modify respiratory outcomes in BPD, possibly independently of severity.

Health-related quality of life of caregivers of children with congenital diaphragmatic hernia

OBJECTIVE

Congenital diaphragmatic hernia (CDH) is a congenital defect associated with significant mortality and morbidity. We sought to assess the health-related quality of life (HRQoL) for caregivers of infants/children with CDH and determine risk factors for poorer HRQoL.

METHODS

Families were recruited from a CDH-specific outpatient clinic and HRQoL was assessed by a validated HRQoL instrument (PedsQLTM Family Impact Module) at several time points. Mixed models were used to identify demographic and clinical factors associated with worse HRQoL for caregivers.

RESULTS

A total of 29 subjects were recruited at a mean age of 2.4 ± 2.3 years. In terms of defect size, 6.9% had a Type A, 37.9% a Type B, 31.0% a Type C, and 24.1% a Type D. The mean HRQoL score at the first encounter was 67.6 ± 18.3; scores are reported from 0 to 100 with higher scores representing the higher reported quality of life. Lower median household incomes (p = .021) and use of extracorporeal membrane oxygenation (p = .013) were associated with poorer HRQoL scores. The presence of respiratory symptoms decreased HRQoL for caregivers, including daytime symptoms (p < .001) and nighttime symptoms (p < .001). While emergency department visits were not associated with a decrease in HRQoL, hospital admissions (p = .002), and reoperations for CDH (p < .001) were.

CONCLUSION

Our study found a reduced quality of life associated with socioeconomic factors and severity of ongoing disease. Further study is needed to confirm these findings and identify strategies for aiding families cope with the chronicity of this congenital disease.

Factors That Impact the Timing and Removal of Gastrostomy Placement/Nissen Fundoplication in Children with Bronchopulmonary Dysplasia

OBJECTIVE

 The study aimed to identify factors that impact timing of gastrostomy placement/removal and Nissen fundoplication (NF) in infants with bronchopulmonary dysplasia (BPD).

STUDY DESIGN

 Clinical data were reviewed retrospectively from patients recruited from the Johns Hopkins Bronchopulmonary Dysplasia Clinic (January 1, 2014-December 31, 2018).

RESULTS

 Patients with gastrostomy tubes (GTs) placed in the neonatal intensive care unit (NICU) were older at discharge (p < 0.001) and less likely to have abnormal upper gastrointestinal series findings (p = 0.005) than those with GTs placed after NICU discharge. Patients with NF had lower mean gestational ages (p = 0.011), longer NICU stays (p = 0.019), more frequent home ventilation requirements (p = 0.005), and greater likelihood of pulmonary hypertension (p = 0.032) compared with those without. Median age of GT removal was 61.6 months. Patients with GTs were weaned from supplemental oxygen and/or home ventilation before GT removal (p < 0.001).

CONCLUSION

 Patients with GT/NF were more medically complex than those with GT alone. Patients were more likely to be weaned from home respiratory support before GT removal.

KEY POINTS

· Patients with GT/NF were more medically complex than those with GT alone.. · Patients were more likely to be weaned from home respiratory support before GT removal.. · Patients with GTs placed in NICU were older at discharge and less likely to have abnormal upper gastrointestinal series result..

Predictors of pulmonary function at 6 years of age in infants with bronchopulmonary dysplasia

RATIONALE

Bronchopulmonary dysplasia (BPD) is a major complication of premature birth and the most common cause of chronic lung disease in infancy. Previous studies have shown that children with a history of BPD have impaired lung function in childhood compared to their term counterparts. However, little is known about potential modifiable factors that alter lung function trajectories and subsequent respiratory morbidity in this population.

OBJECTIVES

To identify potential modifiable risk factors for the development of impaired lung function in patients with a history of prematurity and bronchopulmonary dysplasia.

METHODS

Growth parameters (birth, 2 years old, 6 years old) and pulmonary function testing (6 years old) were retrospectively reviewed for subjects (n = 598) recruited from an outpatient BPD clinic who were born ≤36 weeks gestation and were ≥5 years of age.

RESULTS

Of the 598 recruited subjects, 88 (14.7%) performed adequate pulmonary function testing at approximately 6 years of age. The mean forced expiratory volume in 1 s global lung initiative (GLI) Z-score was -1.31 with lower values associated with Nissen fundoplication. The mean forced vital capacity GLI Z-score was -0.72 with lower values associated with higher amounts of oxygen required at time of initial hospital discharge and Nissen fundoplication.

CONCLUSION

Our study found that children with BPD have lower predicted lung function values. Although growth parameters at age 2 and 6 years did not correlate with lung function values at 6 years of age; use and greater requirement for supplemental oxygen and the presence of a Nissen fundoplication at discharge were associated with lower lung function. Prospective studies should focus on identifying modifiable risk factors that could minimize the impact of BPD on later lung function.

Cystic Fibrosis

Cystic fibrosis (CF) is one of the most commonly diagnosed genetic disorders. Clinical characteristics include progressive obstructive lung disease, sinusitis, exocrine pancreatic insufficiency leading to malabsorption and malnutrition, liver and pancreatic dysfunction, and male infertility. Although CF is a life-shortening disease, survival has continued to improve to a median age of 46.2 years due to earlier diagnosis through routine newborn screening, promulgation of evidence-based guidelines to optimize nutritional and pulmonary health, and the development of CF-specific interdisciplinary care centers. Future improvements in health and quality of life for individuals with CF are likely with the recent development of mutation-specific modulator therapies. In this review, we will cover the current understanding of the disease manifestations, diagnosis, and management as well as common complications seen in individuals with CF.

Effects of Obstructive Sleep Apnea and Obesity on Morphine Pharmacokinetics in Children

BACKGROUND

Obesity increases susceptibility to chronic pain, increases metabolism, and is associated with obstructive sleep apnea syndrome (OSAS), all which can complicate perioperative pain management of patients. In addition, obesity and OSAS can cause elevation of the adipose-derived hormone leptin, which increases metabolism. We hypothesized that obesity along with sleep apnea and leptin independently enhance morphine pharmacokinetics.

METHODS

Children 5-12 years of age who were presenting for surgery were administered a morphine dose of 0.05 mg/kg. Blood was collected at baseline and at subsequent preset times for pharmacokinetic analysis of morphine and its metabolites. Three groups were studied: a nonobese group with severe OSAS, an obese group with severe OSAS, and a control group.

RESULTS

Thirty-four patients consisting of controls (n = 16), nonobese/OSAS (n = 8), and obese/OSAS (n = 10) underwent analysis. The obese/OSAS group had a higher dose-adjusted mean maximum morphine concentration (CMAX) over 540 minutes compared to the controls (P < .001) and those with only OSAS (P = .014). The obese/OSAS group also had lower volume of distribution (Vd) when compared to OSAS-only patients (P = .007). In addition, those in the obese/OSAS group had a higher morphine 3-glucuronide (M3G) maximum concentration (P = .012) and a higher ratio of M3G to morphine than did the control group (P = .011). Time to maximum morphine 6-glucuronide (M6G) concentration was significantly lower in both nonobese/OSAS and obese/OSAS groups than in the control group (P < .005). C-reactive protein (CRP), interleukin (IL)-10, and leptin were all higher in the obese/OSAS group than in controls (P = .004, 0.026, and <0.001, respectively), and compared to OSAS-only patients, CRP (P = .013) and leptin (P = .002) levels were higher in the obese/OSAS group.

CONCLUSIONS

The combination of obesity and OSAS was associated with an increase in morphine metabolism compared with that in normal-weight controls. Our previous study in mice demonstrated that obesity from leptin deficiency decreased morphine metabolism, but that metabolism normalized after leptin replacement. Leptin may be a cause of the increased morphine metabolism observed in obese patients.

Endostatin and ST2 are predictors of pulmonary hypertension disease course in infants

INTRODUCTION

Pulmonary hypertension (PH) is a common comorbidity of cardiopulmonary disease. Endostatin, an inhibitor of angiogenesis, is elevated in neonates with lung disease. ST2 is a heart failure biomarker correlated with PH in adults. We hypothesized that these biomarkers may be useful in diagnosing PH and categorizing its severity in infants.

METHODS

Endostatin, ST2, and NT-proBNP plasma concentrations from 26 infants with PH and 21 control infants without PH were correlated with echocardiographic and clinical features using regression models over time.

RESULTS

Endostatin, ST2, and NT-proBNP concentrations were elevated in PH participants versus controls (p < 0.0001). Endostatin was associated with right ventricular dysfunction (p = 0.014), septal flattening (p = 0.047), and pericardial effusion (p < 0.0001). ST2 concentrations predicted right to left patent ductus arteriosus flow (p = 0.009). NT-proBNP was not associated with PH features.

CONCLUSIONS

Endostatin and ST2 concentrations were associated with echocardiographic markers of worse PH in infants and may be better predictors than existing clinical standards.

Indoor Air Pollution Sources and Respiratory Symptoms in Bronchopulmonary Dysplasia

OBJECTIVE

To evaluate the impact of exposure to indoor air pollution on respiratory health outcomes (healthcare utilization, symptoms, medication use) in infants and children with bronchopulmonary dysplasia (BPD).

STUDY DESIGN

A total of 244 subjects were included from the Johns Hopkins Bronchopulmonary Dysplasia registry. Parents completed an environmental exposure questionnaire including secondhand smoke and indoor combustion (gas/propane heat, gas or wood stove, gas/wood burning fireplace) exposures in the home. Respiratory symptoms, both acute (healthcare utilization, steroid/antibiotic use) and chronic (cough/wheeze, nocturnal cough, use of beta-agonists, tolerance of physical activity), were also collected.

RESULTS

Three-quarters of the infants were exposed to at least 1 combustible source of air pollution in the home, and this exposure was associated with an increased risk of hospitalization in infants and children on home respiratory support. Only 14% of the study population reported secondhand smoke exposure, but we found that this was associated with chronic respiratory symptoms, including activity limitation and nocturnal cough. Infants on respiratory support also had increased daytime cough and wheezing. Approximately one-third reported having an air purifier in the home, and its presence attenuated the effect of secondhand smoke exposure on reported activity limitation.

CONCLUSIONS

Exposure to combustible sources of indoor air pollution was associated with increased respiratory morbidity in a group of high risk of infants with BPD. Our results support that indoor air pollution is a modifiable risk factor for respiratory health in infants with BPD.