Short- and Long-Term Complications of Bronchopulmonary Dysplasia

Nasal High-Flow Therapy Versus Low-Flow Oxygen Therapy Post-Discharge in Infants With Bronchopulmonary Dysplasia: A Retrospective Observational Study

INTRODUCTION

Low-flow oxygen therapy (LFOT) has been the only option for infants with bronchopulmonary dysplasia (BPD) requiring supplemental oxygen after discharge for years. Nasal high-flow therapy (NHFT) has more recently become available as a home device. We compared the impact of NHFT and LFOT on respiratory morbidity and lung function over the first 4 years in infants with BPD requiring respiratory support post-discharge.

METHOD

We retrospectively analyzed data on respiratory morbidity and lung function assessed by tidal breathing flow-volume loop (TBFVL) analysis available from follow-up visits of infants with BPD discharged home with LFOT or NHFT up to 4 years. We compared long-term respiratory outcomes by applying a mixed model, adjusting for mechanical ventilation, overall respiratory support duration, pulmonary hypertension, oxygen therapy, caffeine therapy, and smoking exposure.

RESULTS

We included 26 infants discharged with LFOT and 47 with NHFT. The two groups were homogeneous for baseline demographics and BPD severity. Infants in the NHFT group were weaned from respiratory support earlier compared to the LFOT group (median [IQR] 8.0 [4.0; 12.0] vs 14.5 [6.0; 21.5] months, p 0.046). After applying a mixed model, the NHFT group showed a lower incidence of upper (p = 0.025) and lower respiratory tract infections (p = 0.003), wheezing (p: 0.001), and need for bronchodilator (p = 0.028) and systemic steroids (p < 0.001) during the initial 4 years. Lung function testing did not highlight between-group differences.

CONCLUSIONS

NHFT as an alternative to LFOT may positively impact long-term clinical outcomes of infants with BPD requiring noninvasive respiratory support post-discharge.

Bronchopulmonary dysplasia and ventilation-associated outcomes after pediatric tracheostomy

OBJECTIVES

The objective of this study is to determine the time to ventilator liberation and decannulation after tracheostomy placement in children with bronchopulmonary dysplasia (BPD) and pulmonary hypertension.

METHODS

A prospective cohort study included all children (<18 years old) who underwent tracheostomy between 2015 and 2021 with or without a diagnosis of BPD. The primary outcomes were time to ventilator liberation, tracheostomy decannulation, or death with tracheostomy in place.

RESULTS

A total of 303 children met inclusion with a median (interquartile range [IQR]) age at tracheostomy of 6.9 (IQR: 4.0-49.5) months. A diagnosis of BPD was made for 42% (N = 127) and this group was younger (5.1 vs. 24.5 months, p < .001) and more often had pulmonary hypertension (68% vs. 24%, p < .001). Children with BPD spent a median of 2.9 years (IQR: 1.6-4.0) on ventilation compared to 1.9 years (IQR: 0.9-3.7) for children without BPD (p = .009). The time to decannulation was greater among children with BPD (3.4 vs. 1.8 years, p < .001). However, unadjusted estimates of ventilator liberation (hazard ratio [HR]: 1.05, 95% confidence interval [95% CI]: 0.77-1.44) and decannulation (HR: 1.11, 95% CI: 0.74-1.66) over time were not prolonged by BPD. Pulmonary hypertension was associated with shorter time to death (adjusted HR [aHR] = 1.99, 95% CI: 1.17-3.38, p = .01), while BPD was associated with longer time to death (aHR: 0.38, 95% CI: 0.22-0.67, p = .001).

CONCLUSION

BPD is associated with increased ventilation and duration of tracheostomy but over time many children with BPD will wean off the ventilator and be decannulated. Pulmonary hypertension and not BPD is associated with increased time to death after tracheostomy.

Perception of quality of life in school-age children born before 32 weeks of gestational age

Preterm infants with bronchopulmonary dysplasia (BPD) are at increased risk of disruptions in their quality of life (QoL) at school age, often associated with respiratory morbidity and the need for ongoing hospital care. The objective of this study is to assess the impact of BPD on the perceived quality of life in preterm infants at school age. We conducted a prospective observational study of infants born at less than 32 weeks gestation who were admitted to our neonatal unit between January 2012 and December 2014. These children were followed up, and at ages 8 to 10 years, their quality of life was assessed using the Pediatric Quality of Life (PedsQL) questionnaire, with higher scores indicating poorer quality of life. The study included 102 patients with a mean gestational age of 29.42 weeks (SD 1.87) and a mean birth weight of 1221.36 g (SD 347.25), with an average age of 8.59 years (SD 0.90) at the time of the survey. Patients with BPD 2-3 exhibited a significantly poorer perception of "total quality of life" (p = 0.03) and in the "social activities" domain (p = 0.02) compared to those without BPD or with BPD 1, even after adjusting for gestational age in a multivariate model. No significant differences were observed for the "health and activities" domain (p = 0.31), "emotional state" domain (p = 0.58), or "school activities" domain (p = 0.33). Patients who experienced asthma symptoms during follow-up had a poorer perception of total quality of life than those who did not (20.53 (SD 6.19) vs. 11.89 (SD 1.44), p < 0.01). No significant differences were found between patients without a diagnosis of BPD and those with grade 1 BPD. Similarly, no significant differences were observed when comparing patients of less than 28 weeks gestational age and more than 28 weeks of gestational age.

CONCLUSION

In our population of preterm school-aged children with grades 2-3 BPD, worse perceived quality of life was reported compared to those with no BPD or grade 1 BPD. Preterm children who developed asthma symptoms during the follow-up period also reported lower perceived quality of life. No differences in QoL were observed between patients with no BPD and those with grade 1 BPD, or between those born before and after 28 weeks of gestation. These findings highlight the importance of assessing the QoL in preterm patients with BPD, particularly those with grade 2-3 BPD or asthma symptoms, as early assessment can help identify patients who may benefit from targeted interventions to improve quality of life and long-term outcomes.

WHAT IS KNOWN

• Survival rates of extremely preterm infants have increased significantly in recent years, but respiratory morbidity, particularly bronchopulmonary dysplasia, remains a common problem. The impact of BPD on the quality of life of preterm infants, particularly at school age, is still debated. BPD is associated with an increased risk of asthma and abnormal lung function, but its effect on QoL is not fully understood.

WHAT IS NEW

• Preterm infants with grade 2-3 BPD have a significantly worse perception of QoL at school age, especially in the domain of "social activities". This finding emphasises the need for long-term follow-up and possible interventions to improve QoL, especially in terms of social integration. Asthma symptoms during childhood also contribute to poorer QoL perceptions, highlighting the importance of early diagnosis and effective treatment.

Neonatal multimorbidity and the phenotype of premature aging in preterm infants

Multimorbidity is the co-occurrence of multiple chronic health problems, associated with aging, frailty, and poor functioning. Children born preterm experience more multimorbid conditions in early life compared to term-born peers. Though neonatal multimorbidity is linked to poor health-related quality of life, functional outcomes, and peer group participation, gaps in our theoretical understanding and conceptualization remain. Drawing from life course epidemiology and the Developmental Origins of Heath and Disease models, we offer a framework that neonatal multimorbidity reflects maturational vulnerability posed by preterm birth. The impact of such vulnerability on health and development may be further amplified by adverse exposures and interventions within the environment of the neonatal intensive care unit. This can be exacerbated by disadvantaged home or community contexts after discharge. Uncovering the physiologic and social antecedents of multiple morbid conditions in the neonatal period and their biological underpinnings will allow for more accurate risk-prediction, counseling, and care planning for preterm infants and their families. According to this framework, the maturational vulnerability to multimorbidity imparted by preterm birth and its negative effects on health and development are not predetermined or static. Elucidating pathways of early biologic and physical aging will lead to improvements in care and outcomes. IMPACT: Multimorbidity is associated with significant frailty and dysfunction among older adults and is indicative of early physiologic aging. Preterm infants commonly experience multimorbidities in the newborn period, an underrecognized threat to long-term health and development. We offer a novel framework incorporating multimorbidity, early cellular aging, and life course health development to innovate risk-prediction, care-planning, and therapeutics.

Nintedanib preserves lung growth and prevents pulmonary hypertension in a hyperoxia-induced lung injury model

BACKGROUND

Bronchopulmonary dysplasia (BPD), the chronic lung disease associated with prematurity, is characterized by poor alveolar and vascular growth, interstitial fibrosis, and pulmonary hypertension (PH). Although multifactorial in origin, the pathophysiology of BPD is partly attributed to hyperoxia-induced postnatal injury, resulting in lung fibrosis. Recent work has shown that anti-fibrotic agents, including Nintedanib (NTD), can preserve lung function in adults with idiopathic pulmonary fibrosis. However, NTD is a non-specific tyrosine kinase receptor inhibitor that can potentially have adverse effects on the developing lung, and whether NTD treatment can prevent or worsen risk for BPD and PH is unknown.

HYPOTHESIS

We hypothesize that NTD treatment will preserve lung growth and function and prevent PH in an experimental model of hyperoxia-induced BPD in rats.

METHODS

Newborn rats were exposed to either hyperoxia (90%) or room air (RA) conditions and received daily treatment of NTD or saline (control) by intraperitoneal (IP) injections (1 mg/kg) for 14 days, beginning on postnatal day 1. At day 14, lung mechanics were measured prior to harvesting lung and cardiac tissue. Lung mechanics, including total respiratory resistance and compliance, were measured using a flexiVent system. Lung tissue was evaluated for radial alveolar counts (RAC), mean linear intercept (MLI), pulmonary vessel density (PVD), and pulmonary vessel wall thickness (PVWT). Right ventricular hypertrophy (RVH) was quantified with cardiac weights using Fulton's index (ratio of right ventricle to the left ventricle plus septum).

RESULTS

When compared with RA controls, hyperoxia exposure reduced RAC by 64% (p < 0.01) and PVD by 65% (p < 0.01) and increased MLI by 108% (p < 0.01) and RVH by 118% (p < 0.01). Hyperoxia increased total respiratory resistance by 94% and reduced lung compliance by 75% (p < 0.01 for each). NTD administration restored RAC, MLI, RVH, PVWT and total respiratory resistance to control values and improved PVD and total lung compliance in the hyperoxia-exposed rats. NTD treatment of control animals did not have adverse effects on lung structure or function at 1 mg/kg. When administered at higher doses of 50 mg/kg, NTD significantly reduced alveolar growth in RA controls, suggesting dose-related effects on normal lung structure.

CONCLUSIONS

We found that NTD treatment preserved lung alveolar and vascular growth, improved lung function, and reduced RVH in experimental BPD in infant rats without apparent adverse effects in control animals. We speculate that although potentially harmful at high doses, NTD may provide a novel therapeutic strategy for prevention of BPD and PH.

IMPACT

Anti-fibrotic therapies may be a novel therapeutic strategy for the treatment or prevention of BPD. High-dose anti-fibrotics may have adverse effects on developing lungs, while low-dose anti-fibrotics may treat or prevent BPD. There is very little preclinical and clinical data on the use of anti-fibrotics in the developing lung. Dose timing and duration of anti-fibrotic therapies may be critical for the treatment of neonatal lung disease. Currently, strategies for the prevention and treatment of BPD are lacking, especially in the context of lung fibrosis, so this research has major clinical applicability.

Effect of Low Dose Glucocorticoid Inhalation on Bronchopulmonary Dysplasia in Premature Infants

The aim of the study was to explore the effect of low dose glucocorticoid on bronchopulmonary dysplasia in premature infants, to provide new ideas for clinical prevention and cure of bronchopulmonary dysplasia in premature infants. The 144 cases of premature infants were divided into 72 each: control group and experimental group. Control group received routine clinical prevention and cure, while experimental group was received low dose glucocorticoid on the basis of control group. The serum interleukin-10 (IL-10) , interleukin-8 (IL-8), and transforming growth factor-1 (TGF-β1) before and after treatment were compared between two groups. The incidence and severity of bronchopulmonary dysplasia was compared between two groups. The mechanical ventilation time, oxygen inhalation time and hospitalization time in two groups were recorded, and the body mass, head circumference and body length at 30 days after birth were assessed in both groups. After treatment, the serum IL-10 level in experimental group was increased and IL-8, TGF-β1 levels were decreased compared with control group (p <0.05). The incidence rate of bronchopulmonary dysplasia in experimental group was 13.89% and the disease severity in experimental group was significantly reduced (p<0.05). Both groups exhibited no notable adverse reactions (p>0.05). Low-dose glucocorticoids have a significant preventive and therapeutic effect on bronchopulmonary dysplasia in preterm infants, and have a high safety, showing high clinical application value for bronchopulmonary dysplasia in preterm infants.

Temporal Dynamics of Oxidative Stress and Inflammation in Bronchopulmonary Dysplasia

Bronchopulmonary dysplasia (BPD) is the most common lung complication of prematurity. Despite extensive research, our understanding of its pathophysiology remains limited, as reflected by the stable prevalence of BPD. Prematurity is the primary risk factor for BPD, with oxidative stress (OS) and inflammation playing significant roles and being closely linked to premature birth. Understanding the interplay and temporal relationship between OS and inflammation is crucial for developing new treatments for BPD. Animal studies suggest that OS and inflammation can exacerbate each other. Clinical trials focusing solely on antioxidants or anti-inflammatory therapies have been unsuccessful. In contrast, vitamin A and caffeine, with antioxidant and anti-inflammatory properties, have shown some efficacy, reducing BPD by about 10%. However, more than one-third of very preterm infants still suffer from BPD. New therapeutic agents are needed. A novel tripeptide, N-acetyl-lysyltyrosylcysteine amide (KYC), is a reversible myeloperoxidase inhibitor and a systems pharmacology agent. It reduces BPD severity by inhibiting MPO, enhancing antioxidative proteins, and alleviating endoplasmic reticulum stress and cellular senescence in a hyperoxia rat model. KYC represents a promising new approach to BPD treatment.

[Role of reactive oxygen species/silent information regulator 1 in hyperoxia-induced bronchial epithelial cell injury]

OBJECTIVES

To investigate the effect of reactive oxygen species (ROS)/silent information regulator 1 (SIRT1) on hyperoxia-induced mitochondrial injury in BEAS-2B cells.

METHODS

The experiment was divided into three parts. In the first part, cells were divided into H0, H6, H12, H24, and H48 groups. In the second part, cells were divided into control group, H48 group, H48 hyperoxia+SIRT1 inhibitor group (H48+EX 527 group), and H48 hyperoxia+SIRT1 agonist group (H48+SRT1720 group). In the third part, cells were divided into control group, 48-hour hyperoxia+N-acetylcysteine group (H48+NAC group), and H48 group. The ROS kit was used to measure the level of ROS. Western blot and immunofluorescent staining were used to measure the expression levels of SIRT1 and mitochondria-related proteins. Transmission electron microscopy was used to observe the morphology of mitochondria.

RESULTS

Compared with the H0 group, the H6, H12, H24, and H48 groups had a significantly increased fluorescence intensity of ROS (P<0.05), the H48 group had significant reductions in the expression levels of SIRT1 protein and mitochondria-related proteins (P<0.05), and the H24 and H48 groups had a significant reduction in the fluorescence intensity of mitochondria-related proteins (P<0.05). Compared with the H48 group, the H48+SRT1720 group had significant increases in the expression levels of mitochondria-related proteins and the mitochondrial aspect ratio (P<0.05), and the H48+EX 527 group had a significant reduction in the mitochondrial area (P<0.05). Compared with the H48 group, the H48+NAC group had a significantly decreased fluorescence intensity of ROS (P<0.05) and significantly increased levels of SIRT1 protein, mitochondria-related proteins, mitochondrial area, and mitochondrial aspect ratio (P<0.05).

CONCLUSIONS

The ROS/SIRT1 axis is involved in hyperoxia-induced mitochondrial injury in BEAS-2B cells.

Role of Myeloperoxidase, Oxidative Stress, and Inflammation in Bronchopulmonary Dysplasia

Bronchopulmonary dysplasia (BPD) is a lung complication of premature births. The leading causes of BPD are oxidative stress (OS) from oxygen treatment, infection or inflammation, and mechanical ventilation. OS activates alveolar myeloid cells with subsequent myeloperoxidase (MPO)-mediated OS. Premature human neonates lack sufficient antioxidative capacity and are susceptible to OS. Unopposed OS elicits inflammation, endoplasmic reticulum (ER) stress, and cellular senescence, culminating in a BPD phenotype. Poor nutrition, patent ductus arteriosus, and infection further aggravate OS. BPD survivors frequently suffer from reactive airway disease, neurodevelopmental deficits, and inadequate exercise performance and are prone to developing early-onset chronic obstructive pulmonary disease. Rats and mice are commonly used to study BPD, as they are born at the saccular stage, comparable to human neonates at 22-36 weeks of gestation. The alveolar stage in rats and mice starts at the postnatal age of 5 days. Because of their well-established antioxidative capacities, a higher oxygen concentration (hyperoxia, HOX) is required to elicit OS lung damage in rats and mice. Neutrophil infiltration and ER stress occur shortly after HOX, while cellular senescence is seen later. Studies have shown that MPO plays a critical role in the process. A novel tripeptide, N-acetyl-lysyltyrosylcysteine amide (KYC), a reversible MPO inhibitor, attenuates BPD effectively. In contrast, the irreversible MPO inhibitor-AZD4831-failed to provide similar efficacy. Interestingly, KYC cannot offer its effectiveness without the existence of MPO. We review the mechanisms by which this anti-MPO agent attenuates BPD.

Effects of bradycardia, hypoxemia and early intubation on bronchopulmonary dysplasia in very preterm infants: An observational study

BACKGROUND

Bronchopulmonary dysplasia (BPD) is the most common pulmonary complication in preterm infants.

OBJECTIVES

The study aimed to explore the effects of bradycardia, hypoxemia, and early intubation on BPD in very preterm infants.

METHODS

This is a prospective observational cohort study. Preterm infants with a mean gestational age of 28.67 weeks were recruited from two level III neonatal intensive care units (NICUs) in Taiwan. Continuous electrocardiography was used to monitor heart rates and oxygen saturation (SpO2). Infants were monitored for heart rates of <100 beats per minute and SpO2 levels of <90 % lasting for 30 s. Generalized estimating equations were used to analyze the effects of bradycardia, hypoxemia, and early intubation on BPD in very preterm infants. Model fit was visually assessed using receiver operating characteristic curve analysis.

RESULTS

Bradycardia, hypoxemia, and early intubation significantly increased the odds of BPD among the preterm infants (N = 39) during NICU stay; the odds ratios for bradycardia, hypoxemia, and early intubation for BPD versus non-BPD were 1.058, 1.013, and 29.631, respectively (all p < 0.05). A model combining bradycardia, hypoxemia, and early intubation accurately predicted BPD development (area under the curve = 0.919).

CONCLUSIONS

Bradycardia, hypoxemia, and early intubation significantly increased the odds of BPD among very preterm infants during NICU stay. The model combining bradycardia, hypoxemia, and early intubation accurately predicted BPD development.

Severe Bronchopulmonary Dysplasia Adversely Affects Brain Growth in Preterm Infants

INTRODUCTION

Bronchopulmonary dysplasia (BPD) is associated with neurodevelopmental outcomes of preterm infants, but its effect on brain growth in preterm infants after the neonatal period is unknown. This study aimed to evaluate the effect of severe BPD on brain growth of preterm infants from term to 18 months of corrected age (CA).

METHODS

Sixty-three preterm infants (42 with severe BPD and 21 without severe BPD) who underwent magnetic resonance imaging at term equivalent age (TEA) and 18 months of CA were studied by using the Infant Brain Extraction and Analysis Toolbox (iBEAT). We measured segmented brain volumes and compared brain volume and brain growth velocity between the severe BPD group and the non-severe BPD group.

RESULTS

There was no significant difference in brain volumes at TEA between the groups. However, the brain volumes of the total brain and cerebral white matter in the severe BPD group were significantly smaller than those in the non-severe BPD group at 18 months of CA. The brain growth velocities from TEA to 18 months of CA in the total brain, cerebral cortex, and cerebral white matter in the severe BPD group were lower than those in the non-severe BPD group.

CONCLUSION

Brain growth in preterm infants with severe BPD from TEA age to 18 months of CA is less than that in preterm infants without severe BPD.

Association of Fetal Lung Development Disorders with Adult Diseases: A Comprehensive Review

Fetal lung development is a crucial and complex process that lays the groundwork for postnatal respiratory health. However, disruptions in this delicate developmental journey can lead to fetal lung development disorders, impacting neonatal outcomes and potentially influencing health outcomes well into adulthood. Recent research has shed light on the intriguing association between fetal lung development disorders and the development of adult diseases. Understanding these links can provide valuable insights into the developmental origins of health and disease, paving the way for targeted preventive measures and clinical interventions. This review article aims to comprehensively explore the association of fetal lung development disorders with adult diseases. We delve into the stages of fetal lung development, examining key factors influencing fetal lung maturation. Subsequently, we investigate specific fetal lung development disorders, such as respiratory distress syndrome (RDS), bronchopulmonary dysplasia (BPD), congenital diaphragmatic hernia (CDH), and other abnormalities. Furthermore, we explore the potential mechanisms underlying these associations, considering the role of epigenetic modifications, transgenerational effects, and intrauterine environmental factors. Additionally, we examine the epidemiological evidence and clinical findings linking fetal lung development disorders to adult respiratory diseases, including asthma, chronic obstructive pulmonary disease (COPD), and other respiratory ailments. This review provides valuable insights for healthcare professionals and researchers, guiding future investigations and shaping strategies for preventive interventions and long-term care.

Exploring the Association of Male Sex With Adverse Outcomes in Severe Bronchopulmonary Dysplasia: A Retrospective, Multicenter Cohort Study

BACKGROUND

Bronchopulmonary dysplasia (BPD) is a significant contributor to morbidity and death in infants who are born premature. Male sex is an independent risk factor for the development of BPD. However, whether male sex is associated with adverse outcomes that occur after formal diagnosis of severe BPD prior to hospital discharge remains unclear.

RESEARCH QUESTION

Is male sex associated with a higher risk of adverse outcomes in infants with established severe BPD?

STUDY DESIGN AND METHODS

A retrospective, multicenter cohort study of infants enrolled in the BPD Collaborative Registry from January 1, 2015, to June 29, 2022, was performed. Demographics, clinical characteristics, and outcomes were stratified by sex (ie, male vs female). Regression modeling was used to estimate the association of sex with the primary composite outcome of death or tracheostomy at hospital discharge.

RESULTS

We identified 1,156 infants with severe BPD, defined at 36 weeks postmenstrual age by the National Institutes of Health 2001 consensus definition. The cohort was predominantly male (59% male infants, 41% female infants). However, rates of mechanical ventilation at 36 weeks postmenstrual age (ie, type 2 severe BPD) did not differ by sex. Overall mortality rates within the cohort were low (male infants, 5.3%; female infants, 3.6%). The OR of death or tracheostomy for male-to-female infants was 1.0 (95% CI, 0.7-1.5).

INTERPRETATION

Our results lead us to speculate that, although sex is an important variable that contributes to the development and pathogenesis of severe BPD, it does not appear to be associated with adverse outcomes in this cohort of infants with established disease. The surprising results raise important questions surrounding the temporal role of biological sex in the development of severe BPD and its progression during the neonatal ICU stay. As we explore the phenotypes and endotypes of BPD, it is imperative to consider how sex modulates the disease from birth through hospital discharge.

Early-life pulmonary viral infection leads to long-term functional and lower airway structural changes in the lungs

Early-life respiratory virus infections have been correlated with enhanced development of childhood asthma. In particular, significant numbers of respiratory syncytial virus (RSV)-hospitalized infants go on to develop lung disease. It has been suggested that early-life viral infections may lead to altered lung development or repair that negatively impacts lung function later in life. Our data demonstrate that early-life RSV infection modifies lung structure, leading to decreased lung function. At 5 wk postneonatal RSV infection, significant defects are observed in baseline pulmonary function test (PFT) parameters consistent with decreased lung function as well as enlarged alveolar spaces. Lung function changes in the early-life RSV-infected group continue at 3 mo of age. The altered PFT and structural changes induced by early-life RSV were mitigated in TSLPR-/- mice that have previously been shown to have reduced immune cell accumulation associated with a persistent Th2 environment. Importantly, long-term effects were demonstrated using a secondary RSV infection 3 mo following the initial early-life RSV infection and led to significant additional defects in lung function, with severe mucus deposition within the airways, and consolidation of the alveolar spaces. These studies suggest that early-life respiratory viral infection leads to alterations in lung structure/repair that predispose to diminished lung function later in life.NEW & NOTEWORTHY These studies outline a novel finding that early-life respiratory virus infection can alter lung structure and function long-term. Importantly, the data also indicate that there are critical links between inflammatory responses and subsequent events that produce a more severe pathogenic response later in life. The findings provide additional data to support that early-life infections during lung development can alter the trajectory of airway function.

Trends in bronchopulmonary dysplasia and respiratory support among extremely preterm infants in China over a decade

OBJECTIVE

Bronchopulmonary dysplasia (BPD) is one of the most serious complications affecting extremely preterm infants. We aimed to evaluate temporal trends in BPD and administration of respiratory support among extremely preterm infants in China over a decade.

METHODS

This was a retrospective study using data from a multicenter database, which included infants born less than 28 weeks' gestation discharged from 68 tertiary neonatal care centers in China between 2010 and 2019. Changes in rates and severity of BPD, as well as modalities and duration of respiratory support, were evaluated.

RESULTS

Among 4808 eligible infants with gestational age (GA) of 21+6/7  to 27+6/7 weeks and a mean (SD) birth weight of 980 (177) g, no significant change of median GA was found over time. Overall, 780 (16.2%) infants died before 36 weeks' postmenstrual age, 2415 (50.2%) were classified as having no BPD, 917 (19.1%) developed Grade 1 BPD, 578 (12.0%) developed Grade 2 BPD, and 118 (2.5%) developed Grade 3 BPD. The rate of BPD increased from 20.8% in 2010 to 40.7% in 2019 (aRR for trend, 1.081; 95% confidence interval, 1.062-1.099), especially for Grade 1 and Grade 2. Although survival to discharge improved over the decade, the overall survival without BPD did not change during the study period. The use of invasive mechanical ventilation (IMV) remained unchanged. However, the use of noninvasive ventilation (NIV) increased from 71.5% in 2010 to 89.8% in 2019. Moreover, the median duration of NIV increased over time, from 17.0 (4.8, 34.0) days in 2010 to 33.0 (21.0, 44.0) days in 2019, without significant change in the duration of IMV.

CONCLUSIONS

Although survival increased over the decade and respiratory support practices changed significantly between 2010 and 2019 in China, with increased use and duration of NIV, there was an increased rate of BPD and survival without BPD has not improved.

[Management of lung diseases under ultrasound monitoring: potential to make bronchopulmonary dysplasia in preterm infants as an avoidable disease]

Bronchopulmonary dysplasia (BPD) is the most common chronic lung disease in preterm infants. Despite significant progress in the understanding of its etiology, mechanisms, prevention, and treatment, the prognosis remains poor. BPD not only has a high mortality rate but also causes persistent respiratory, neurological, and cardiovascular impairments in survivors. The author's team has successfully prevented the occurrence of BPD by managing neonatal lung diseases under lung ultrasound monitoring for nearly 7 years, opening up a new approach in BPD prevention. This article provides a brief overview of the approach, aiming to facilitate further research and provide more scientifically sound management strategies to prevent or minimize the occurrence of BPD.

Stem/Progenitor Cells and Related Therapy in Bronchopulmonary Dysplasia

Bronchopulmonary dysplasia (BPD) is a chronic lung disease commonly seen in preterm infants, and is triggered by infection, mechanical ventilation, and oxygen toxicity. Among other problems, lifelong limitations in lung function and impaired psychomotor development may result. Despite major advances in understanding the disease pathologies, successful interventions are still limited to only a few drug therapies with a restricted therapeutic benefit, and which sometimes have significant side effects. As a more promising therapeutic option, mesenchymal stem cells (MSCs) have been in focus for several years due to their anti-inflammatory effects and their secretion of growth and development promoting factors. Preclinical studies provide evidence in that MSCs have the potential to contribute to the repair of lung injuries. This review provides an overview of MSCs, and other stem/progenitor cells present in the lung, their identifying characteristics, and their differentiation potential, including cytokine/growth factor involvement. Furthermore, animal studies and clinical trials using stem cells or their secretome are reviewed. To bring MSC-based therapeutic options further to clinical use, standardized protocols are needed, and upcoming side effects must be critically evaluated. To fill these gaps of knowledge, the MSCs' behavior and the effects of their secretome have to be examined in more (pre-) clinical studies, from which only few have been designed to date.

The role of rhIGF-1/BP3 in the prevention of pulmonary hypertension in bronchopulmonary dysplasia and its underlying mechanism

BACKGROUND

This study aimed to determine whether postnatal treatment with recombinant human IGF-1 (rhIGF-1)/binding peptide 3 (BP3) ameliorates lung injury and prevents pulmonary hypertension (PH) in bronchopulmonary dysplasia (BPD) models.

METHODS

We used two models of BPD in this study: one model that was associated with chorioamnionitis (CA), stimulated by intra-amniotic fluid and exposure to lipopolysaccharide (LPS), whereas the other was exposed to postnatal hyperoxia. Newborn rats were treated with rhIGF-1/BP3 (0.2 mg/Kg/d) or saline via intraperitoneal injection. The study endpoints included the wet/dry weight (W/D) ratio of lung tissues, radial alveolar counts (RACs), vessel density, right ventricular hypertrophy (RVH), lung resistance, and lung compliance. Hematoxylin and eosin (H&E) and Masson staining were used to evaluate the degree of lung injury and pulmonary fibrosis. IGF-1 and eNOS expression were detected using western blotting or quantitative reverse transcriptase polymerase chain reaction (qRT-PCR). The levels of SP-C, E-cadherin, N-cadherin, FSP1, and Vimentin in the lung tissues were detected by immunofluorescence.

RESULTS

LPS and hyperoxia treatment increased lung injury and pulmonary fibrosis, enhanced RVH and total respiratory resistance, and decreased RAC, pulmonary vascular density and pulmonary compliance in young mice (all p < 0.01). Simultaneously, LPS and hyperoxia induced an increase in epithelial-mesenchymal transition (EMT) in airway epithelial cells. However, rhIGF-1/BP3 treatment reduced lung injury and pulmonary fibrosis, decreased RVH and total respiratory resistance, and enhanced RAC, pulmonary vascular density and pulmonary compliance, as well as inhibited EMT in airway epithelial cells in LPS and hyperoxia treated mice.

CONCLUSION

Postnatal rhIGF-1/BP3 treatment relieved the effects of LPS or hyperoxia on lung injury and prevented RVH, providing a promising strategy for the treatment of BPD.

Impaired pulmonary function mediates inattention in young adults born extremely preterm

AIM

To test whether poor childhood pulmonary function explains the relationship between extremely preterm (EP) birth and attention-deficit/hyperactivity disorder (ADHD) symptoms in young adulthood.

METHODS

EPICure birth cohort participants include children born <26 weeks' gestation in the United Kingdom and Ireland in 1995 and their term-born classmates. Predictor was EP birth. Outcomes were inattention/hyperactivity subscale z-scores at 19 years. Forced expiratory volume (FEV1) z-scores in childhood and young adulthood were mediators. We used recursive path analysis to determine the direct effect of EP birth on inattention/hyperactivity and its indirect effect through pulmonary function.

RESULTS

Ninety EP and 47 term-born participants had pulmonary function testing at 11 and 19 years. Inattention z-scores were higher in the EP group (mean difference 0.55 [95% CI 0.11, 0.99]) but not hyperactivity. Compared to term-born peers, EP participants had lower FEV1 z-scores at 11 (mean difference-1.35 [95% CI -1.72, -0.98]) and 19 (mean difference-1.29 [95% CI -1.65, -0.92]). Path models revealed that childhood pulmonary function explained the relationship between EP birth and inattention.

CONCLUSIONS

Extremely preterm young adults have increased risk for inattention compared to term-born peers. Poor pulmonary function appears to underlie this risk. The mechanisms responsible remain unclear and warrant further study.

Effect of systemic hydrocortisone in ventilated preterm infants on parent-reported behavioural outcomes at 2 years' corrected age: follow-up of a randomised clinical trial

OBJECTIVE

To report the parent-reported behavioural outcomes of infants included in the Systemic Hydrocortisone To Prevent Bronchopulmonary Dysplasia in preterm infants study at 2 years' corrected age (CA).

DESIGN

Randomised placebo-controlled trial.

SETTING

Dutch and Belgian neonatal intensive care units.

PATIENTS

Infants born <30 weeks' gestation and/or birth weight <1250 g, and ventilator dependent in the second week of life.

INTERVENTION

Infants were randomly assigned to a 22-day course of systemic hydrocortisone (cumulative dose 72.5 mg/kg; n=182) or placebo (n=190).

MAIN OUTCOME MEASURES

Parent-reported behavioural outcomes at 2 years' CA assessed with the Child Behavior Checklist (CBCL 1½-5).

RESULTS

Parents completed the CBCL of 183 (70% (183/262)) infants (hydrocortisone group, n=96; placebo group, n=87). Multiple imputation was used to account for missing data. Infants with critically elevated T-scores (>55) were found in 22.9%, 19.1% and 29.4% of infants for total, internalising and externalising problems, respectively; these scores were not significantly different between groups (mean difference -1.52 (95% CI -4.00 to 0.96), -2.40 (95% CI -4.99 to 0.20) and -0.81 (95% CI -3.40 to 1.77), respectively). In the subscales, we found a significantly lower T-score for anxiety problems in the hydrocortisone group (mean difference -1.26, 95% CI -2.41 to -0.12).

CONCLUSION

This study found high rates of behaviour problems at 2 years' CA following very preterm birth, but these problems were not associated with hydrocortisone treatment initiated between 7 and 14 days after birth in ventilated preterm infants.

TRIAL REGISTRATION NUMBER

NTR2768; EudraCT 2010-023777-19.