Bronchopulmonary dysplasia: A review of pathogenesis and pathophysiology

Changes in adrenomedullin in bronchoalveolar lavage fluid with chorioamnionitis in a sheep-based model

BACKGROUND

Adrenomedullin (AM) is a potent angiogenic, antioxidant and anti-inflammatory peptide protecting the developing lung from injury due to bronchopulmonary dysplasia (BPD) of the preterm infant. At this stage, no data on the potential effects of chorioamnionitis (CA) occurrence and glucocorticoids (GC) administration on AM in developing lungs are still lacking.

OBJECTIVE

to investigate, in a sheep-based model, the positive/side-effects of combined exposure to CA and GC on AM concentrations measured in bronchoalveolar lavage fluid (BALF).

METHODS

Time-mated ewes were randomly admitted to one of six treatment groups receiving injection: saline (controls); lipopolysaccharide (L) in intra-amniotic fluid treated alone at 7 or 14 d before delivery or associated with betamethasone (B) intramuscularly; B treated alone (7d) or associated with L (14d). Lambs were surgically delivered at 120 days gestation and euthanized. BALF was used for AM measurement in the studied groups.

RESULTS

AM BALF levels significantly (p < 0.05, for all) changed both to B and L exposure in a time-dependent manner. The latter was characterized by AM levels at short term superimposable to controls, whilst significantly (p > 0.05) decreased at long-term. The former showed increased AM at short and decreased at long-term (p < 0.05, for all), respectively.

CONCLUSIONS

the present results showing AM BALF changes in a sheep-based model support the AM role in the hemodynamic patterns due to CA and BPD occurrence and open the way to further studies investigating the role of vasoactive agents as trustable markers of lung development/damage.

Proline betaine facilitates angiogenesis in bronchopulmonary dysplasia

BACKGROUND

Bronchopulmonary dysplasia (BPD) is prevalent and severe diseases in preterm infants, characterized by abnormal lung development. This study aims to investigate the therapeutic potential of proline betaine, a natural alkaloid recognized for its vasculo-protective and anti-inflammatory properties, in BPD model.

METHODS

Network pharmacology was utilized to predict the targets of proline betaine and BPD-related genes (BPD-RGs). In vitro, HUVECs were treated with proline betaine to evaluate its effects on proliferation and angiogenesis. In vivo, a hyperoxia-induced BPD rat model (85 % oxygen, first day to 14th day) was used to evaluate the effects of proline betaine on pulmonary injury, angiogenesis and fibrosis.

RESULTS

We identified a total of 100 proline-betaine targets and 825 BPD-RGs, with 20 shared targets between them. These shared targets modulated inflammation, immune response, hypoxia, and vascular homeostasis, especially the vascular phenotype. In vitro, proline betaine significantly enhanced the activity, number of tubes, and capillary length of HUVECs. The pro-angiogenic effect of proline betaine on HUVECs was dose-dependent. The hyperoxia-induced BPD rat model corroborated these findings. In vivo, proline betaine increased the radial alveolar count and reduced the mean linear intercept and collagen content in the lung. Mechanistically, proline betaine upregulated VEGF and VEGFR2 expression as well as MEK/ERK pathway activity. Notably, blocking the VEGFR2 and MEK/ERK pathways made proline betaine less effective as a medicine.

CONCLUSION

Proline betaine enhances angiogenesis and mitigates pulmonary injury through the MEK/ERK pathway. These findings suggest that proline betaine could serve as a novel therapeutic strategy for managing BPD in neonates.

Gender-specific effects of prenatal polystyrene nanoparticle exposure on offspring lung development

Nanoplastics are widely present in the environment. Exposure to environmental pollutants during pregnancy can have adverse effects on fetal development and health. Establishing a link between nanoplastics and Bronchopulmonary Dysplasia (BPD) requires further investigation. In this study, we examined the impact of prenatal exposure to 80 nm polystyrene nanoparticles (PS-NPs) on offspring lung development, taking into account potential gender-specific effects. Pregnant female mice were exposed to PS-NPs through oropharyngeal aspiration, and critical data on lung development were collected at postnatal days 1, 7, and 21. We found that exposure to PS-NPs reduced birth weight in female offspring and significantly increased lung weight in both male and female offspring by PND 21. Maternal exposure led to a reduction in alveolar numbers across offspring, with distinct underlying mechanisms observed between sexes. In female offspring, the reduction in alveolar numbers was linked to disrupted surfactant protein expression, significant inflammation, and increased apoptosis and fibrosis. In male offspring, impaired angiogenesis was the primary factor contributing to the increased risk of BPD. The impact on alveolar development was substantial in both genders. This study underscores the gender-specific impacts of prenatal nanoplastic exposure on lung development and offers new evidence and direction for future research on the cross-generational respiratory toxicity of PS-NPs.

Feasibility of volume targeted- positive pressure ventilation for preterm infants requiring invasive ventilation in the delivery room

BACKGROUND

Positive pressure ventilation (PPV) with high variability in delivered tidal volume (TV) may cause volutrauma. We aimed to assess feasibility of providing Volume Targeted-Positive Pressure Ventilation (VT-PPV) to preterm infants receiving invasive mechanical ventilation via endotracheal tube in the delivery room (DR).

DESIGN/METHODS

TV measurements were available from a respiratory function monitor (RFM) to adjust peak inspiratory pressures to target TV of 4-6 ml/kg for participants in the intervention cohort (VT-PPV). This data was compared with a historic cohort (HC), where providers were blinded from RFM measurements.

RESULTS

With VT-PPV, goal TV (4-6 ml/kg) was provided 40.1% of times (vs. HC:23.6%, p = 0.002); low TV (<4 ml/kg) was provided 8.6% of times (vs. HC:28.1%, p ≤ 0.001). There was no difference in higher TV provided in the two cohorts.

CONCLUSION

Providing VT-PPV in intubated preterm infants may be feasible in DR and may result in increased number of breaths in target range.

The Central Role of Cytochrome P450 Reductase (CPR) in Hyperoxic Lung Injury

INTRODUCTION

Hyperoxic lung injury results from excessive supplemental oxygen therapy in conditions such as bronchopulmonary dysplasia (BPD) in preterm infants and acute respiratory distress syndrome (ARDS) in adults. This review explores the role of cytochrome P450 reductase (CPR) in hyperoxic lung injury.

AREAS COVERED

Hyperoxia induces the production of reactive oxygen species in excessive amounts, overwhelming the body's antioxidant defenses and exacerbating lung injury in ARDS/BPD. This review examines the differential roles of CPR-dependent enzymes in the context of hyperoxic lung injury. Additionally, we highlight the potential of targeting CPR to study mechanisms of lung injury and leverage gene-editing technologies to deepen our understanding of CPR-mediated pathways. This review consolidates existing knowledge on CPR-dependent processes and their roles in hyperoxic lung injury, based on a literature search conducted in the PubMed database for studies published between 1988 and 2024.

EXPERT OPINION

This review emphasizes the need for a deeper understanding of disease mechanisms, particularly CPR-mediated pathways. As a regulatory hub for ROS modulation and enzyme activity, CPR represents a promising target, offering a unified strategy to mitigate hyperoxic lung injury and improve outcomes in BPD/ARDS.

Home oxygen therapy for Thai preterm infants with bronchopulmonary dysplasia. What are the predictive factors for successful weaning: a 20-year review

BACKGROUND

Consequences of lung injury and inflammation in preterm infants with bronchopulmonary dysplasia (BPD) contribute to prolonged oxygen requirements. Home oxygen therapy (HOT) is an alternative way of respiratory support in infant with BPD. However, there is no consensus on weaning guidelines. Our objective is to identify the median age of HOT discontinuation and the factors that might predict the duration of HOT in a resource poor country.

METHODS

All preterm (≤ 36 weeks' gestation) infants diagnosed with BPD who required HOT after discharged from Ramathibodi Hospital during January 2000 - December 2019 comprised this retrospective study. Timing of HOT withdrawal was identified. Demographic data, severity of BPD, maternal condition, respiratory support, comorbidities, complications, and growth were recorded and analyzed as factors associated of home oxygen withdrawal.

RESULTS

Of 8581 preterm infants born during the 20-year period, 563 (6.6%) had BPD. Among 40 infants treated with HOT, 18 (45%) were successfully weaned from oxygen within 12 months. The median corrected age (CA) of oxygen withdrawal was 13.8 months (8.5, 22.1). Longer duration of total respiratory support, longer length of hospital stay and poor growth determined by weight, length and head circumference were associated with longer duration of HOT. Greater weight gain was associated with a shorter duration of HOT at 12 months CA (adjusted OR, 1.97; 95% CI, 1.13-3.23; p = 0.015).

CONCLUSIONS

The median corrected age of oxygen withdrawal in Thai BPD infants was 13.8 months. Severe BPD and poor linear growth were associated with prolonged HOT.

Azithromycin for Preventing Bronchopulmonary Dysplasia in Extremely Preterm Infants: A Cohort Study

OBJECTIVES

To test the effect of azithromycin in reducing bronchopulmonary dysplasia (BPD) risk in extremely preterm infants (EPI) without pulmonary infection.

STUDY DESIGN

A retrospective cohort study was performed in EPI in a tertiary unit from September 2018 to September 2022. Since only Ureaplasma species positive infants were treated with azithromycin, we included infants without Ureaplasma species (no azithromycin treatment) and those diagnosed with Ureaplasma species colonization (azithromycin treatment) in the study, while infants with Ureaplasma species pneumonia were excluded. The primary outcome was grade II+ BPD, defined as BPD of grade II or higher according to the updated NICHD criteria (2018). Multiple logistic regression analysis was used to identify the independent association between grade II+ BPD and azithromycin treatment.

RESULTS

A total of 237 EPIs were included in the current study, of which 202 infants were classified as no azithromycin treatment (Ureaplasma species negative) and 35 infants were classified as azithromycin treatment (Ureaplasma species colonization). Clinical characteristics were similar between groups. Infants treated with azithromycin had a significantly lower rate of grade II+ BPD (8.6% vs. 31.2%, p = 0.006), and shorter duration of invasive ventilation (0 vs. 3 days, p = 0.045) compared to untreated ones. After adjusting for confounders, azithromycin treatment was significantly associated with reduced risk of grade II+ BPD in the whole cohort (odd ratio [OR] 0.211, 95% CI: 0.056, 0.786, p = 0.020], and infants absent of other pulmonary infection (OR 0.115, 95% CI: 0.014, 0.979, p = 0.048).

CONCLUSION

Azithromycin is associated with a reduced risk of grade II+ BPD in EPIs, likely due to its anti-inflammatory effect.

LncRNA MIAT binding to GATA3 activates MAPK signaling pathway and influences bronchopulmonary dysplasia

Bronchopulmonary dysplasia (BPD) manifests in premature neonates with aberrant pulmonary function. Numerous long non-coding RNAs (lncRNAs) have been implicated in the pathogenesis of BPD. This study aims to elucidate the impact of the lncRNA myocardial infarction-associated transcript (MIAT) on the initiation and progression of BPD. Initially, BPD murine models were established through hyperoxia induction in newborn mice. Subsequently, MIAT and GATA binding protein 3 (GATA3) expression levels were assessed, and intravenous administration of short hairpin RNAs (shRNAs) targeting MIAT and GATA3 was performed. Pulmonary histological alterations were examined through histological staining. Levels of inflammatory mediators were quantified using enzyme-linked immunosorbent assay (ELISA) kits. The interaction between MIAT and GATA3 was scrutinized through RNA immunoprecipitation, RNA pull-down, and fluorescence in situ hybridization. The downstream mechanisms of GATA3 were explored using bioinformatics analysis. In summary, lncRNA MIAT exhibited elevated expression in the lung tissues of BPD-afflicted mice. MIAT localized to the nucleus and interacted with GATA3, thereby activating the mitogen-activated protein kinase (MAPK) pathway. Knockdown of MIAT or silencing of GATA3 attenuated the inflammatory response, deactivated the MAPK pathway, and ameliorated BPD symptoms in mice, on the other hand, p-Cresyl sulfate potassium can activate the MAPK signaling pathway and attenuates the effects of si-MIAT or si-GAT3. These improvements were characterized by enhanced alveolar differentiation and reduced glycogen and collagen deposition. In conclusion, lncRNA MIAT plays a pivotal role in activating the MAPK pathway and exacerbating hyperoxia-induced BPD in mice through the binding to GATA3. It's an important discovery for the pathogenesis of BPD and may provide some new treatment for infants diagnosed with BPD.

Effects of early parenteral nutrition on the development of premature infants born at 22-23 weeks of gestation: a retrospective cohort study evaluated by brain magnetic resonance imaging

BACKGROUND

The effect of early parenteral nutrition (EPN) therapy on brain development in extremely premature infants at a gestational age (GA) of 22-25 weeks remains unknown.

OBJECTIVES

This study investigated the effect of EPN therapy on GA 22 to 25 weeks of gestation using magnetic resonance imaging (MRI) global brain abnormality score (GBAS).

SUBJECTS

Forty-six preterm infants born before 26 weeks of gestation were divided into the GA 22-23 weeks (GA 22-23; n = 18) and GA 24-25 weeks (GA 24-25; n = 28) group.

METHODS

Each infant received ≥3.0 g/kg/day of amino acids from day 1 of life and ≥1.0 g/kg/day of lipid emulsion the next day. Weight change during hospitalization, GBAS at discharge, and developmental quotient (DQ) until three years old were compared between the groups.

RESULTS

GA 22-23 showed long-term postnatal weight loss, but weight at 41 weeks of postmenstrual age did not differ between the groups. The GBAS score was not significantly different, but the head circumference was smaller in GA 22-23 than in GA 24-25 until 2 years old. The DQ at 1-1.5 years old was lower in GA 22-23 than that of GA 24-25; however, there was no significant difference in DQ after 2 years old between the groups.

CONCLUSIONS

The effect of nutritional support with EPN therapy in premature neonates born at <24 weeks of gestation may still be inadequate. GBAS is useful for assessing brain development in very preterm infants, and the importance of nutritional support during the first few weeks of life should continue to be explored.

Oxygen in the newborn period: Could the oxygen reserve index offer a new perspective?

Oxygen therapy has been one of the main challenges in neonatal intensive care units (NICU). The guidelines currently in use try to balance the burden of hypoxia and hyperoxia such as retinopathy of prematurity, bronchopulmonary dysplasia, and death. The goal of this paper is to review neonatal oxygenation and the impact of hyperoxia and hypoxia in neonatal outcomes as well as review the available literature concerning the use of Oxygen Reserve Index (ORiTM) in clinical practice and its potential in Neonatology, particularly in NICU. Pulse oximetry has been used to monitor oxygenation in newborns with the advantage of being a noninvasive and continuous parameter, however it has limitations in detecting hyperoxemic states due to the flattening of the hemoglobin dissociation curve. The ORiTM is a new parameter that has been used to detect moderate hyperoxia and, when used in addiction to spO2, could be helpful in both hypoxia and hyperoxia. Studies using this tool are mainly in the adult population, during anesthetic procedures with only a small number of studies being performed in pediatric context. Oxygen targets remain a major problem for neonatal population and regardless of the efforts made to establish a safe oxygenation range, a more individualized approach seems to be the more appropriate pathway. ORiTM monitoring could help defining how much oxygen is too much for each newborn. Despite its promising potential, ORiTM is still a recent technology that requires more studies to determine its true potential in clinical practice.

Association of TNF-α genetic variants with neonatal bronchopulmonary dysplasia: consolidated results

Objectives

Inflammation is increasingly recognized as a key factor in the pathophysiology of bronchopulmonary dysplasia (BPD). While previous research has established significant links between TNF-α polymorphisms and BPD susceptibility, further validation of these associations is needed. This study aims to examine the relationship between TNF-α polymorphisms and the risk of BPD.

Methods

All relevant articles published before October 1, 2024, have been screened in the PubMed, Web of Science, CNKI, and Scopus databases.

Results

A total of 14 case-control studies were conducted: five studies with 1,252 cases and 1,377 controls on -308G/A, three studies with 1,180 cases and 1,194 controls on -238G/A, four studies with 149 cases and 192 controls on -857C/T, and two studies with 82 cases and 162 controls on 1,031 T/C. A significant association was found between the TNF-α -238G/A polymorphism and the risk of BPD. However, no significant relationships were observed for the TNF-α -308G/A, -857C/T, and 1,031 T/C polymorphisms regarding BPD susceptibility.

Conclusions

Our findings indicate a significant association between the TNF-α -238G/A polymorphism and the susceptibility to BPD in preterm neonates, suggesting potential biomarkers for its pathogenesis. However, this meta-analysis has limitations, including possible publication bias and heterogeneity due to the limited number of studies, which may affect the reliability of our conclusions. Moreover, population variability further complicates the interpretation of the link between TNF-α polymorphisms and BPD risk.

Influence of inhaled nitric oxide on bronchopulmonary dysplasia in preterm infants with PPHN or HRF at birth: a propensity score matched study

Background

Bronchopulmonary Dysplasia (BPD) is a chronic lung disease affecting preterm infants, with limited prevention and treatment options. Inhaled Nitric Oxide (iNO) is sometimes used to treat Persistent Pulmonary Hypertension of the Newborn (PPHN) and Hypoxemic Respiratory Failure (HRF), and its impact on BPD development remains debated.

Objective

To assess whether iNO-related factors are potential contributors to the development of BPD Grade Ⅱ-Ⅲ in very premature infants (VPI) diagnosed with PPHN or HRF at birth using Propensity Score Matching (PSM).

Methods

We conducted a retrospective cohort study of infants born at 22-32 weeks gestation with PPHN or HRF, treated with iNO for over 3 h. PSM matched groups by gestational age, birth weight, and gender, etc. Multivariate logistic regression evaluated the association between iNO treatment and BPD outcomes to identify influencing factors, while Restricted Cubic Spline (RCS) and mediation analysis examined iNO dose effects and potential mediators like mechanical ventilation time and oxygenation index (OI).

Results

A higher initial iNO dose was significantly associated with a reduced risk of BPD Grade Ⅱ-Ⅲ (adjusted OR = 0.68, 95% CI: 0.52-0.89, p < 0.01). Additionally, administration of iNO within the first 7 days of life was identified as an important influencing factor No significant mediation effects were observed for factors such as mechanical ventilation time and OI.

Conclusion

A higher initial iNO dose within the first 7 days was associated with a reduced risk of BPD Grade Ⅱ-Ⅲ in VPI with PPHN or HRF.

Purinergic P2X7 receptor mediates hyperoxia-induced injury in pulmonary microvascular endothelial cells via NLRP3-mediated pyroptotic pathway

Background

Hyperoxia-induced injury is a well-recognized cause of bronchopulmonary dysplasia (BPD). Existing research studies have not well elucidated the exact mechanisms underlying hyperoxia-induced cellular damage. This study examines the involvement of the P2X7 receptor (P2X7R) in hyperoxia-induced damage to human pulmonary microvascular endothelial cells (HPMVECs) via the NOD-like receptor family, pyrin domain-containing protein 3 (NLRP3) pathway.

Methods

HPMVECs developing hyperoxia-induced injury were subjected to the treatment of either selective inhibitors or a P2X7R/NLRP3 agonist. Western blot analysis assisted in the quantification of the levels of P2X7R, NLRP3, caspase-1, and gasdermin D (GSDMD). Additionally, the release of TNF-α, IL-1β, and IL-18 was assessed by ELISA and qRT-PCR.

Results

Exposure to hyperoxia diminished cell viability and escalated the levels of P2X7R, caspase-1, NLRP3, GSDMD, and N-terminal-GSDMD. This exposure notably increased the release of TNF-α, IL-1β, and IL-18 in HPMVECs. Notably, the suppression of P2X7R using the inhibitor A438079 decreased pyroptosis and inflammatory responses. Conversely, stimulation of P2X7R by 3'-O-(4-benzoylbenzoyl) adenosine 5'-triphosphate (BzATP) triggered pyroptosis, while inhibition of NLRP3 with glibenclamide ameliorated the damage induced by BzATP.

Conclusions

The P2X7R/NLRP3 pathway crucially affects the hyperoxia-induced inflammation and pyroptosis in HPMVECs, hinting the potential of blocking P2X7R/NLRP3-mediated pyroptotic pathway as a valuable therapeutic strategy for BPD.

Childhood outcomes following discharge from a referral bronchopulmonary dysplasia program

OBJECTIVES

The primary objective of this study was to profile the childhood health, development, and health-related quality of life (HR QoL) for children with the most severe bronchopulmonary dysplasia (BPD), those discharged from a quaternary referral program.

STUDY DESIGN

We collected cross-sectional data through telephone interviews with 282 families of children ages 18 months to 11 years who had been discharged from a BPD referral program.

RESULTS

Respiratory morbidities were near universal, with 42% of children ever having required a tracheostomy and severity of these morbidities correlated with parent-reported health and QoL. Developmental morbidities were also marked: 97% required an individualized educational plan. While respiratory morbidities and overall health improved over time, developmental morbidities were increasingly prominent, resulting in lower quality of life.

CONCLUSIONS

Among children referred to a quaternary BPD program, respiratory and developmental morbidities are on numerous counts more severe than any reported in the literature.

Research progress of microvascular development in bronchopulmonary dysplasia

Bronchopulmonary dysplasia (BPD) is a chronic lung disease that arises during the neonatal period, and its underlying mechanisms are still not fully understood. The disorder of microvascular development plays a significant role in the development of BPD. This article presents a comprehensive review of the advancements made in understanding the mechanisms and treatment approaches related to microvascular development in the pathogenesis of BPD.

A Survey of Minimally Invasive Surfactant Use in the United States

OBJECTIVE

 Minimally invasive surfactant therapy (MIST) has become the standard of care in delivering surfactant noninvasively in many parts of the world, particularly throughout Europe; however, centers in the United States have been slower to adopt it. The most recent assessment of the use of MIST in the United States was in 2018 by Kurepa et al. Considering the increasing evidence favoring MIST, this paper reassessed the current rate of utilization and aims to examine barriers to MIST implementation.

STUDY DESIGN

 A web-based survey was distributed to approximately 4,500 individuals in the American Academy of Pediatrics Section of Neonatal-Perinatal Medicine (AAP SoNPM) mailing list. The questions were aimed at addressing MIST usage in the United States, examining barriers for neonatology providers to implement MIST into their practice, and determining the use of sedation during the MIST procedure.

RESULTS

 Of the 381 respondents, 39% used MIST as part of their practice, which was an increase from 15% in 2018. The most prevalent barrier to implementation was the lack of procedural training. There was a large increase in the use of sedation for the procedure compared with 2018.

CONCLUSION

 MIST use among AAP SoNPM respondents has more than doubled since 2018; InSurE (INtubation-SURfactant delivery Extubation) remains the most prevalent method of surfactant delivery in non-intubated patients. The list of different types of barriers and comments provided by respondents can be a resource for units planning to implement MIST.

KEY POINTS

· The usage of MIST in the United States.. · What are the barriers to MIST implementation?. · The usage of sedation during MIST procedure..

The potential therapeutic effect of human umbilical cord mesenchymal stem cell-derived exosomes in bronchopulmonary dysplasia

Bronchopulmonary dysplasia (BPD) is a chronic lung disease of preterm infants, with its incidence rising due to improved survival rates of these infants. BPD results from a combination of prenatal and postnatal factors, such as mechanical ventilation, oxygen toxicity, and infections, all of which significantly impact the prognosis and growth of affected infants. Current treatment options for BPD are largely supportive and do not address the underlying pathology. Exosomes are cell-derived bilayer-enclosed membrane structures enclosing proteins, lipids, RNAs, growth factors, cytokines and metabolites. They have become recognized as crucial regulators of intercellular communication in various physiological and pathological processes. Previous studies have revealed the therapeutic potential of human umbilical cord mesenchymal stem cells-derived exosomes (HUCMSCs-Exos) in promoting tissue repair and regeneration. Therefore, HUCMSCs-Exos maybe a promising and effective therapeutic modality for BPD. In this review, we firstly provide a comprehensive overview of BPD, including its etiology and the mechanisms of lung injury. Then we detail the isolation, characterization, and contents of HUCMSCs-Exos, and discuss their potential mechanisms of HUCMSCs-Exos in BPD treatment. Additionally, we summarize current clinical trials and discuss the challenges in translating these findings from bench to bedside. This review aims to lay the groundwork for future clinical applications of HUCMSCs-Exos in treating BPD.

Inter-hospital variations in the respiratory outcomes of very and extremely pre-term infants: A cohort study in Japan

BACKGROUND

Hospital-level and international variations exist in the management strategies of bronchopulmonary dysplasia (BPD). However, studies evaluating hospital-level variations in the respiratory outcomes of pre-term infants associated with differing management strategies of BPD are lacking.

OBJECTIVE

Herein, we aimed to assess inter-hospital variations in the respiratory outcomes of BPD in very pre-term and extremely pre-term infants.

METHODS

In this cohort study, the administrative claims and discharge summary data were extracted from 276 hospitals in Japan between April 2014 and March 2016. This study assessed neonates of a gestational age of 22-31 weeks old, who had been hospitalised for ≥7 days. The primary outcome was a BPD defined using any respiratory support, such as supplemental oxygen, high-flow nasal cannula, CPAP, or mechanical ventilation at 36 weeks PMA. The median odds ratio (MOR) was calculated using a multilevel logistic regression model, including baseline characteristics, comorbidities, and treatment as covariates, to evaluate the inter-hospital variation of the outcome.

RESULTS

Of the 8143 neonates from across 132 hospitals, 53.7% were male, with a mean gestational age (standard deviation) of 28.0 (2.5)-weeks-old and birthweight of 1086 (386) g. Among these patients, BPD occurred in 2737 (33.6%). The MOR was 2.49, representing the median value of odds ratios when comparing two neonates with identical covariates from hospitals with high and low propensity for the outcomes to occur.

CONCLUSIONS

Outcome variations in the BPD were observed among hospitals in Japan, even after adjusting for individual factors, including gestational age, birthweight, comorbidities, and treatments. Thus, in Japan, developing strategies is essential to decrease the BPD rates, while minimising inter-hospital heterogeneity, to improve the healthcare quality for pre-term neonates.

Flexible bronchoscopy in preterm infants with bronchopulmonary dysplasia: findings and complications in a matched control study

Bronchopulmonary dysplasia (BPD) poses a significant challenge as the most common late morbidity of preterm infants. This study aimed to evaluate airway abnormalities in infants with BPD who underwent flexible bronchoscopy (FB) to gain insights into the prevalence of upper airway obstruction and associated complications. A retrospective case-control study was conducted on BPD patients who underwent FB at a tertiary center between 2013 and 2023. BPD patients were matched (1:3) with a reference group based on age, gender, and ethnicity, who also had undergone FB. Demographic data, comorbidities, indications for FB, findings, and complications during and after FB were collected. The study included 50 BPD patients (mean age 1.26 ± 0.9 years, 58% males), and 150 controls. As expected, BPD patients had a lower gestational age, lower birth weight, and longer hospitalizations and were treated with more medications. Abnormal bronchoscopy findings were significantly more common in the BPD group compared to the reference group, with an increased rate of turbinate hypertrophy (OR [95% CI]: 3.44 [1.27-9.37], P = 0.014), adenoid hypertrophy (OR: 2.7 [1.38-5.29], P = 0.004), lingual tonsils (OR: 5.44 [1.29-27.4], P = 0.0024), subglottic stenosis (OR: 6.95 [2.08-27.1], P = 0.002), and tracheomalacia (OR: 2.98 [1.06-8.19], P = 0.034). Complications including desaturation (OR: 3.89 [1.32-11.7], P = 0.013) and PICU admission (OR: 16.6 [2.58-322], P = 0.011) were more frequent in the BPD than in the reference group.

CONCLUSION

The study revealed a high prevalence of structural anomalies leading to upper airway obstruction and complications in infants with BPD undergoing FB. These findings emphasize the importance of careful consideration and preparation for bronchoscopic procedures in this vulnerable population.

WHAT IS KNOWN

• Bronchopulmonary dysplasia (BPD) represents the most prevalent late morbidity among preterm infants. • Preterm infants diagnosed with BPD frequently undergo diagnostic procedures, including flexible and rigid bronchoscopies, to identify structural pathologies within the respiratory tract.

WHAT IS NEW

• A significantly higher prevalence of structural anomalies leading to upper airway obstruction was observed in the BPD group compared to controls. • The incidence of complications during flexible bronchoscopy was higher in the BPD group than in controls.

A Comprehensive Consolidation of Data on the Relationship Between Surfactant Protein-B (SFTPB) Polymorphisms and Susceptibility to Bronchopulmonary Dysplasia

BACKGROUND

This meta-analysis aims to evaluate the potential link between common variations in the Surfactant Protein-B (SFTPB) gene and the risk of bronchopulmonary dysplasia (BPD) in preterm neonates.

METHODS

All pertinent articles published prior to February 1, 2024, in PubMed, Web of Science, EMBASE, CNKI, and Scopus databases were reviewed.

RESULTS

Nineteen case-control studies involving 1149 BPD cases and 1845 non-BPD controls, were analyzed. Combined data indicated a significant link between SFTPB -18 A > C and Intron 4 VNTR polymorphisms with increased BPD susceptibility, while the 1580 C > T polymorphism provides a protective impact on BPD initiation.

CONCLUSIONS

Pooled data indicated a significant association between SFTPB -18 A > C and Intron 4 VNTR polymorphisms with increased BPD risk, whereas the 1580 C > T polymorphism confers protection. These findings suggest a genetic susceptibility to BPD, underscoring the complex interplay of different genetic elements in its development.

Bronchopulmonary dysplasia demonstrates dysregulated autotaxin/lysophosphatidic acid signaling in a neonatal mouse model

BACKGROUND

Bronchopulmonary dysplasia (BPD) is a chronic lung disease affecting premature infants who require oxygen supplementation and ventilator therapy to support their underdeveloped lungs. Autotaxin (ATX), an enzyme that generates the bioactive phospholipid lysophosphatidic acid (LPA), which acts via G-protein coupled receptors, has been implicated in numerous pulmonary diseases. In this study, we explored the pathophysiological role of the ATX/LPA signaling pathway in BPD.

METHODS

Neonatal mice were exposed to normoxia or hyperoxia (85%) for 14 days from birth while being treated with vehicle, ATX inhibitor or LPA receptor 1 (LPA1) inhibitor. In vitro studies utilized human lung fibroblast (HLF) cells exposed to room air, 85% oxygen, or LPA for varying time periods. Supernatants and cells were collected for assays and Western blotting.

RESULTS

Animals exposed to hyperoxia showed elevated expression of ATX, ATX activity, and LPA1. Inhibiting ATX or LPA1 improved alveolarization, reduced inflammation, and mitigated extracellular matrix deposition and lysyl oxidase (LOX) expression. LPA1 inhibition leading to reduced LOX expression was associated with a reduction in phosphorylation of AKT.

CONCLUSION

Hyperoxia increases the expression of ATX and LPA1 associated with increased LOX in the lungs. Targeting the ATX/LPA1 pathway could be a potential therapeutic approach to BPD.

IMPACT

Exposure to hyperoxia increases the expression and activity of autotaxin (ATX), as well as expression of LPA receptor 1 (LPA1). Increased expression of ATX influences extra cellular matrix (ECM) remodeling. Inhibitors targeting the ATX/LPA pathway could offer a new therapeutic approach to bronchopulmonary dysplasia (BPD), potentially mitigating ECM deposition and improving lung development.

Nonlinear relationship between vitamin D status on admission and bronchopulmonary dysplasia in preterm infants

BACKGROUND

This research will explore non-linear relationship between vitamin D status on admission and bronchopulmonary dysplasia (BPD) in preterm infants.

METHODS

Data were retrospectively collected on preterm infants ≤32 weeks gestation and ≥28 weeks gestation hospitalized in our hospital between Jan. 2019 and Jul. 2022, which were classified into BPD and non-BPD groups according to BPD diagnostic criteria. Independent influences between the two groups were staged using comparison of differences between groups, univariate analysis, multivariate analysis, smoothed curve fitting, and threshold effect staging.

RESULTS

255 preterm infants were enrolled in this research, including 135 males and 120 females, with a mean gestational age of 30.59 ± 0.86 weeks. Vitamin D status on admission was an independent protective factor for BPD in preterm infants, with a 6% reduction in the probability of BPD for every 1 ng/ml increase in vitamin D status on admission (p = 0.036). There was also a non-linear relationship, with each 1 ng/ml increase in vitamin D status on admission being associated with an 87% reduction in the incidence of BPD when vitamin D status was <12.82 ng/ml (p = 0.010).

CONCLUSION

Vitamin D status on admission and BPD are non-linearly in preterm infants at 28-32 weeks gestation.

IMPACT STATEMENT

Analyzing the relationship between vitamin D status on admission and BPD. A nonlinear relationship and turning point between vitamin D status on admission and BPD was derived by curve fitting and threshold effect. We provide a new reference point for vitamin D supplementation for the prevention of neonatal BPD and to avoid ineffective overmedication.

Personalized lung care: Bronchopulmonary dysplasia risk prediction tool tailored for neonates born in resource-limited settings

PURPOSE

Predicting bronchopulmonary dysplasia (BPD) to assess the risk-benefit of therapy is necessary considering the side effects of medications. We developed and validated an instrument for predicting BPD and compared it with an instrument currently used for neonates born in a Brazilian hospital.

METHODS

This was a retrospective cohort study of patients born between 2016 and 2020 with a gestational age (GA) between 23 and 30 weeks. Predictive equations were elaborated using methods of component variable selection collected on the 14th day of life; 70% of the sample was randomly selected for the construction of risk prediction equations and the remaining 30% for their validation, application, and comparison with the National Institute of Child Health and Human Development (NICHD) instrument. The sensitivity, specificity, and predictive values of the equations were calculated.

RESULTS

The equation that used variables with p < 5% in Fisher's exact test presented the best results: specificity of 98% and positive predictive value of 93% and could be used for BPD prediction of all small-for-gestational-age (SGA) infants. The NICHD calculator applied to our population had a specificity of 93% and a positive predictive value of 75% and could not be applied to extremely SGA infants.

CONCLUSION

Our tool can predict the risk of BPD on the 14th day of life, has higher specificity and positive predictive value to our population than the NICHD instrument, and can be suitable for SGA infants. The results must be confirmed by applying it to other populations to validate our tool.

Prevalence and Risk Factors of Bronchopulmonary Dysplasia Among Very Premature Infants in a Tunisian Neonatal Intensive Care Unit

INTRODUCTION

Bronchopulmonary dysplasia (BPD) stands as the primary chronic respiratory complication in premature infants, posing a substantial public health concern due to its rising prevalence, potential mortality, and socioeconomic burden.

AIM

The aim of this study was to determine the prevalence of BPD in very preterm infants and identify its associated risk factors.

METHODS

We conducted a retrospective, descriptive, and analytical study including all premature infants born between 26 and 31 weeks of gestation age (GA) who survived beyond the 28th day of life, over a five-year period (2017-2021). Patients were divided into two groups based on the presence or absence of BPD, which was defined by the need for oxygen supplementation for at least 28 days.

RESULTS

we included 231 newborns. The prevalence of BPD was 37.7% among survivors on the 28th day of life and 36.7% among those reaching 36 weeks postmenstrual age. BPD was mild, moderate and severe in 25.2%, 4.9% and 6.6% of cases, respectively. Multivariate analysis identified maternal hypertensive disorders (RR=6.15, 95%CI=[2.27-16.67], p<0.001), chorioamnionitis (RR=4.23, 95%CI=[1.25 -14.27], p=0.02), intrauterine growth restriction (IUGR) (RR =20.4, 95%CI=[3.39 -122.66], p=0.001), GA less than 30 weeks (RR=26.97, 95%CI=[10.23 -71.14], p<0.001), and mechanical ventilation (MV) (RR=5.33, 95%CI=[1.95-14.54], p=0.001) as independent factors associated with BPD occurrence. The mortality rate was 10.3% among patients with BPD versus 0.7% in patients without BPD (p = 0.001).

CONCLUSION

Our study revealed a high prevalence of BPD in very preterm infants and identified several independent risk factors such as maternal hypertensive disorders, IUGR, chorioamnionitis, MV, and GA less than 30 weeks.

miR-3202 inhibits bronchopulmonary dysplasia-mediated apoptosis and oxidative stress in bronchial epithelial cells via targeting RAG1

BACKGROUND

BPD is a refractory disease affecting preterm infants with alveolar dysplasia and declined pulmonary function. However, the molecular mechanism underlying BPD is largely unknown. To explore the pathogenic mechanism of BPD and to facilitate better diagnosis and treatment of this disease.

METHOD

The DEMs and DEGs in BPD vs. Control samples from the miRNA expression data in GSE108754 and mRNA expression data in the GSE108755 were screened, followed by the construction of the miRNA-mRNA regulatory network. DEGs PPI network and hub DEGs analysis were constructed by using the STRING database and Cytoscape software. Functional and pathway enrichment analyses were then performed for these DEGs and DEMs based on the ClusterProfiler package in the R and the miRWalk database. The k-mean algorithm is used to perform clustering analysis of DEGs. Cellular experiments (flow cytometry, western blot, RT-PCR, dual-luciferase reporter assay) were used to validate the results of bioinformatics.

RESULTS

We obtained 20 DEMs and 262 DEGs. A 15 DEMs-11 DEGs regulatory network was constructed. miR-3202-RAG1 is a core sub-network. Hyperoxia induced a cell model of BPD. The upregulation of RAG1 and downregulation of miR-3202 were observed in BPD cells. Furthermore, siRNA targeting RAG1 was transfected into BEAS-2B cells to inhibit its expression and miR-3202 mimics was transfected into the cells to increase its expression. Inhibition of RAG1 and elevation of miR-3202 inhibit cell apoptosis and reduce ROS level caused by hyperoxia. A double-luciferase reporter assay revealed that miR-3202 directly targets RAG1.

CONCLUSION

The miRNA-3202/RAG1 axis contributes into BPD-induced cell apoptosis and ROS production. The present study provides a probable target for the treatment of BPD.

Recombinant CXCL17 Treatment Alleviates Hyperoxia-Induced Lung Apoptosis and Inflammation In Vivo and Vitro by Activating the AKT Pathway: A Possible Therapeutic Approach for Bronchopulmonary Dysplasia

Bronchopulmonary dysplasia (BPD), caused by hyperoxia exposure, is the most common complication affecting preterm infants. The C-X-C motif chemokine ligand 17 (CXCL17) belongs to the chemokine family that plays important roles in various processes, but the function in BPD is unknown. Elevated serum CXCL17 levels were observed in human premature infants with hyperoxia-induced lung injury, suggesting that CXCL17 might be involved in BPD. To further validate our speculation, studies were conducted in a hyperoxia-induced lung injury mouse model and primary murine alveolar epithelial cells Type II (T2AEC) cells exposed to hyperoxia. RT-qPCR and western blot were used to validate CXCL17 expression in newborn mice. Hyperoxia exposure-induced lung injury was determined by assessing the lung wet-weight/dry-weight ratio and histological changes. Oxidative stress and inflammatory factors were examined by ELISA assay and RT-qPCR. Reactive oxygen species (ROS) level was evaluated by DHE staining. Apoptosis was assessed by TUNEL staining and western blot. The results showed that hyperoxia exposure increased CXCL17 levels in newborn mice pups. Hyperoxia exposure increased lung wet-weight/dry-weight ratio, increased alveolar diameter and enlarged alveoli, and reduced surfactant protein C expression. However, recombinant CXCL17 (rCXCL17) treatment alleviated hyperoxia-induced lung injury. rCXCL17 treatment inhibited hyperoxia-induced inflammation, oxidative stress, and apoptosis in neonatal mice. These results were further verified in T2AEC cells. Additionally, rCXCL17 treatment activated the AKT pathway, which is a protective pathway in BPD. Collectively, rCXCL17 alleviates hyperoxia-induced lung injury in neonatal mice by activating the AKT pathway, indicating that CXCL17 may be a promising target for BPD therapy.

Examining the contribution of Notch signaling to lung disease development

Notch pathway is a widely observed signaling system that holds pivotal functions in regulating various developmental cellular functions and operations. The Notch signaling mechanism is crucial for lung homeostasis, damage, and restoration. Based on increasing evidence, the Notch pathway has been identified, as critical for fibrosis and subsequently, the development of chronic fibroproliferative conditions in various organs and tissues. Recent research indicates that deregulation of Notch signaling correlates with the pathogenesis of significant pulmonary conditions, particularly chronic obstructive pulmonary disease (COPD), pulmonary fibrosis, asthma, pulmonary arterial hypertension (PAH), lung carcinoma, and pulmonary abnormalities in some hereditary disorders. In various cellular and tissue environments, and across both physiological and pathological conditions, multiple consequences of Notch activation have been observed. Studies have ascertained that the Notch signaling cascade exhibits close associations with various other signaling systems. This study provides an updated overview of Notch signaling's role, especially its link to fibrosis and its potential therapeutic implications. This study sheds light on the latest findings regarding the mechanisms and outcomes of irregular or lacking Notch activity in the onset and development of pulmonary diseases. As our insight into this signaling mechanism suggests that modulating Notch signaling might hold potential as a valuable additional therapeutic approach in upcoming research.

Epidemiological characteristics and clinical antibiotic resistance analysis of Ureaplasma urealyticum infection among women and children in southwest China

BACKGROUND

The aim of this study was to investigate the epidemiological characteristics and antibiotic resistance patterns of Ureaplasma urealyticum (UU) infection among women and children in southwest China.

METHODS

A total of 8,934 specimens, including urogenital swabs and throat swabs were analyzed in this study. All samples were tested using RNA-based Simultaneous Amplification and Testing (SAT) methods. Culture and drug susceptibility tests were performed on UU positive patients.

RESULTS

Among the 8,934 patients, the overall positive rate for UU was 47.92%, with a higher prevalence observed among women of reproductive age and neonates. The majority of UU positive outpatients were women of reproductive age (88.03%), while the majority of UU positive inpatients were neonates (93.99%). Overall, hospitalization rates due to UU infection were significantly higher in neonates than in women. Further analysis among neonatal inpatients revealed a higher incidence of preterm birth and low birth weight in UU positive inpatients (52.75% and 3.65%, respectively) than in UU negative inpatients (44.64% and 2.89%, respectively), especially in very preterm and extremely preterm neonates. Moreover, the incidence rate of bronchopulmonary dysplasia (BPD) among hospitalized neonatal patients was significantly higher in the UU positive group (6.89%) than in the UU negative group (4.18%). The drug susceptibility tests of UU in the neonatology, gynecology and obstetrics departments exhibited consistent sensitivity patterns to antibiotics, with high sensitivity to tetracyclines and macrolides, and low sensitivity to fluoroquinolones. Notably, UU samples collected from the neonatology department exhibited significantly higher sensitivity to azithromycin and erythromycin (93.8% and 92.9%, respectively) than those collected from the gynecology and obstetrics departments.

CONCLUSIONS

This study enhances our understanding of the current epidemiological characteristics and antibiotic resistance patterns of UU infection among women and children in southwest China. These findings can aid in the development of more effective intervention, prevention and treatment strategies for UU infection.

Evaluating endotracheal tube length in very and extremely preterm infants

OBJECTIVE

Our study objective was to evaluate changes in ETT tube depth throughout the initial intubation course in very and extremely preterm infants in order to evaluate the risk of outgrowing an endotracheal tube (ETT).

METHODS

This was a retrospective cohort study of preterm infants born at <32 weeks of gestation who were admitted to the NICU between 2012 and 2021 and required intubation for mechanical ventilation. Infants who were intubated only for surfactant administration and those with airway malformations were excluded. Descriptive statistics were used to define the range of ETT depths at the time of extubation, stratified by gestational age (<28 weeks vs 28-32 weeks of gestation). Relative ETT depth was defined as the final depth minus the initial depth.

RESULTS

Out of 496 infants, 140 patients met all criteria for inclusion. Descriptive analysis of extubation depths across the populations demonstrated median relative ETT depth of 0 cm for the 28-32-week gestational age group, and -0.25 cm for the <28-week gestational age group. The 95th percentile for both gestational age groups was a relative depth of 0.5 cm and the 99th percentile was 1.0-1.5 cm.

CONCLUSION

The results of our study suggest that the vast majority of patients in the NICU are unlikely to "outgrow" ETT tube length which should be taken into account when deciding where to trim the ETT in order to minimize airway resistance.

A lactobacilli-based inhaled live biotherapeutic product attenuates pulmonary neutrophilic inflammation

Bronchopulmonary dysplasia (BPD) is a chronic lung disease of prematurity. Exposure to noxious stimuli such as hyperoxia, volutrauma, and infection in infancy can have long-reaching impacts on lung health and predispose towards the development of conditions such as chronic obstructive pulmonary disease (COPD) in adulthood. BPD and COPD are both marked by lung tissue degradation, neutrophil influx, and decreased lung function. Both diseases also express a change in microbial signature characterized by firmicute depletion. However, the relationship between pulmonary bacteria and the mechanisms of downstream disease development has yet to be elucidated. We hypothesized that murine models of BPD would show heightened acetylated proline-glycine-proline (Ac-PGP) pathway and neutrophil activity, and through gain- and loss-of-function studies we show that Ac-PGP plays a critical role in driving BPD development. We further test a inhaled live biotherapeutic (LBP) using active Lactobacillus strains in in vitro and in vivo models of BPD and COPD. The Lactobacillus-based LBP is effective in improving lung structure and function, mitigating neutrophil influx, and reducing a broad swath of pro-inflammatory markers in these models of chronic pulmonary disease via the MMP-9/PGP (matrix metalloproteinase/proline-glycine-proline) pathway. Inhaled LBPs show promise in addressing common pathways of disease progression that in the future can be targeted in a variety of chronic lung diseases.

Therapeutic potential of extracellular vesicles derived from human amniotic epithelial cells for perinatal cerebral and pulmonary injury

Lung and brain injury that occurs during the perinatal period leads to lifelong disability and is often driven and/or exacerbated by inflammation. Human amniotic epithelial cells (hAEC), which demonstrate immunomodulatory, anti-fibrotic, and regenerative capabilities, are being explored as a therapeutic candidate for perinatal injury. However, limitations regarding scalable manufacturing, storage, transport, and dose-related toxicity have impeded clinical translation. Isolated therapeutic extracellular vesicles (EVs) from stem and stem-like cells are thought to be key paracrine mediators of therapeutic efficacy. The unique characteristics of EVs suggest that they potentially circumvent the limitations of traditional cell-based therapies. However, given the novelty of EVs as a therapeutic, recommendations around ideal methods of production, isolation, storage, and delivery have not yet been created by regulatory agencies. In this concise review, we discuss the pertinence and limitations of cell-based therapeutics in perinatal medicine. We also review the preclinical evidence supporting the use of therapeutic EVs for perinatal therapy. Further, we summarize the arising considerations regarding adequate cell source, biodistribution, isolation and storage methods, and regulatory roadblocks for the development of therapeutic EVs.

Aspects on Oxygenation in Preterm Infants before, Immediately after Birth, and Beyond

BACKGROUND

Oxygen is crucial for life but too little (hypoxia) or too much (hyperoxia) may be fatal or cause lifelong morbidity.

SUMMARY

In this review, we discuss the challenges of balancing oxygen control in preterm infants during fetal development, the first few minutes after birth, in the neonatal intensive care unit and after hospital discharge, where intensive care monitoring and response to dangerous oxygen levels is more often than not, out of reach with current technologies and services.

KEY MESSAGES

Appropriate oxygenation is critically important even from before birth, but at no time is the need to strike a balance more important than during the first few minutes after birth, when body physiology is changing at its most rapid pace. Preterm infants, in particular, have a poor control of oxygen balance. Underdeveloped organs, especially of the lungs, require supplemental oxygen to prevent hypoxia. However, they are also at risk of hyperoxia due to immature antioxidant defenses. Existing evidence demonstrate considerable challenges that need to be overcome before we can ensure safe treatment of preterm infants with one of the most commonly used drugs in newborn care, oxygen.

Mother's own milk and bronchopulmonary dysplasia in appropriate for gestational age preterm infants

OBJECTIVE

To evaluate the association between mother's own milk (MOM) and bronchopulmonary dysplasia (BPD) in appropriate for gestational age (AGA) preterm infants <32 weeks.

METHODS

Clinical data of AGA preterm infants (24+0/7-31+6/7 weeks) were reviewed. Infants with ≥66% of cumulative prescribed enteral volumes as MOM from birth to 36 weeks were allocated to the high provision of MOM group (H-MOM), whereas those with <66% were assigned to the low provision of MOM group (L-MOM). Multiple regressions were used to assess the association of H-MOM with BPD and oxygen saturation to fraction inspired oxygen ratio (SFR) at 36 weeks.

RESULTS

A total of 1041 infants met the inclusion criteria, with a median provision of cumulative enteral nutrition volumes of 5721 (IQR 2616) mL/kg. Among them, 517 (49.7%) were H-MOM and 524 (50.3%) L-MOM infants. H-MOM showed a reduction in the incidence of BPD to 31.6% compared to L-MOM infants. H-MOM had a lower risk of BPD than L-MOM infants after the adjustment for gestational age, sex, cesarean section, mean SFR at the first hours of life, surfactant administration, patent ductus arteriosus, sepsis, prolonged ventilatory supports/oxygen exposure, and cumulative energy intakes from birth to 36 weeks [aOR: 0.613, p = 0.047]. H-MOM was also associated with a lower risk of SFR in the first quartile at 36 weeks [aOR: 0.616, p = 0.028] than L-MOM.

CONCLUSION

A high provision (≥66%) of enteral volume as MOM from birth to 36 weeks is associated with a reduced risk of both BPD and low SFR at 36 weeks in AGA preterm infants <32 weeks.

Patent Ductus Arteriosus and Lung Magnetic Resonance Imaging Phenotype in Moderate and Severe Bronchopulmonary Dysplasia-Pulmonary Hypertension

Rationale: Hemodynamically significant patent ductus arteriosus (hsPDA) in premature infants has been associated with bronchopulmonary dysplasia (BPD) and pulmonary hypertension (PH). However, these associations remain incompletely understood. Objectives: To assess the associations between hsPDA duration and clinical outcomes, PH, and phenotypic differences on lung magnetic resonance imaging (MRI). Methods: In this retrospective cohort study, we identified all infants with BPD at <32 weeks' gestation who also underwent research lung MRI at <48 weeks' postmenstrual age (PMA) from 2014 to 2022. Clinical echocardiograms were reviewed for hsPDA and categorized as no hsPDA, hsPDA 1-60 days, and hsPDA >60 days. Outcome variables included BPD severity, PH at 36 weeks' PMA, PH after 36 weeks' PMA in the absence of shunt (PH-pulmonary vascular disease [PVD]), tracheostomy or death, and lung phenotype by MRI via modified Ochiai score, indexed total lung volume, and whole-lung hyperdensity. Logistic regression and ANOVA were used. Measurements and Main Results: In total, 133 infants born at 26.2 ± 1.9 weeks, weighing 776 ± 276 g, were reviewed (47 with no hsPDA, 44 with hsPDA 1-60 days, and 42 with hsPDA >60 d). hsPDA duration > 60 days was associated with BPD severity (P < 0.01), PH at 36 weeks' PMA (adjusted odds ratio [aOR], 9.7 [95% confidence interval (CI), 3.3-28.4]), PH-PVD (aOR, 6.5 [95% CI, 2.3-18.3]), and tracheostomy or death (aOR, 3.0 [95% CI, 1.0-8.8]). Duration of hsPDA > 60 days was associated with higher Ochiai score (P = 0.03) and indexed total lung volume (P = 0.01) but not whole-lung hyperdensity (P = 0.91). Conclusions: In infants with moderate or severe BPD, prolonged exposure to hsPDA is associated with BPD severity, PH-PVD, and increased parenchymal lung disease by MRI.

Physical Rehabilitation Using Oromotor Stimulation, Manual Airway Clearance Technique, Positioning, and Tactile and Kinaesthetic Stimulation (PROMPT) Protocol in Low-Birth-Weight Triplets With Neonatal Respiratory Distress: A Case Series

Neonatal respiratory distress syndrome (RDS), a severe respiratory illness that is likely to affect preterm newborns especially those who were born preterm with low birth weight (LBW) or multiple births, is one of the complications that preterm babies are likely to develop. Physical Rehabilitation using Oromotor Stimulation, Manual Airway Clearance Technique, Positioning, and Tactile and Kinaesthetic Stimulations (PROMPT) is the intervention followed in this study to determine its effectiveness in the treatment of RDS in LBW triplets. The PROMPT protocol involves interventions such as manually promoting the airway, positioning, oral motor stimulation, and tactile and kinesthetic stimulation. The study examined triplets of similar weight, 1.23g, 1.36g, and 1.18g, at birth. Thus, all known triplets were suffering from the symptoms of RDS like fast breathing and grunting. They were born via premature delivery at 30+5 weeks of pregnancy. Chest X-rays were used as a diagnostic tool for assessing RDS. At the same time, the PROMPT protocol was administered and significant improvements were seen in respiratory health and there was reduced use of mechanical ventilation. The PROMPT protocol shows how effectively an organized method can be applied to treat RDS in LBW triplets.

Umbilical cord blood-derived therapy for preterm lung injury: a systematic review and meta-analysis

INTRODUCTION

Lung injuries, such as bronchopulmonary dysplasia (BPD), remain a major complication of preterm birth, with limited therapeutic options. One potential emerging therapy is umbilical cord blood (UCB)-derived therapy.

OBJECTIVES

To systematically assess the safety and efficacy of UCB-derived therapy for preterm lung injury in preclinical and clinical studies.

METHODS

A systematic search of MEDLINE, Embase, CENTRAL, ClinicalTrials.gov, and WHO International Trials Registry Platform was performed. A meta-analysis was conducted with Review Manager (5.4.1) using a random effects model. Data was expressed as standardized mean difference (SMD) for preclinical data and pooled relative risk (RR) for clinical data, with 95% confidence intervals (CI). Potential effect modifiers were investigated via subgroup analysis. Certainty of evidence was assessed using the GRADE system.

RESULTS

Twenty-three preclinical studies and six clinical studies met eligibility criteria. Statistically significant improvements were seen across several preclinical outcomes, including alveolarization (SMD, 1.32, 95%CI [0.99, 1.65]), angiogenesis (SMD, 1.53, 95%CI [0.87, 2.18]), and anti-inflammatory cytokines (SMD, 1.68, 95%CI [1.03, 2.34]). In clinical studies, 103 preterm infants have received UCB-derived therapy for preterm lung injury and no significant difference was observed in the development of BPD (RR, 0.93, 95%CI [0.73, 1.18]). Across both preclinical and clinical studies, administration of UCB-derived therapy appeared safe. Certainty of evidence was assessed as "low."

CONCLUSIONS

Administration of UCB-derived therapy was associated with statistically significant improvements across several lung injury markers in preclinical studies. Early clinical studies demonstrated the administration of UCB-derived therapy as safe and feasible but lacked data regarding efficacy.

Association of cord blood Ang-1 and sCD105 levels with bronchopulmonary dysplasia in preterm infants

BACKGROUND

To investigate the relationship between cord blood levels of Angiopoietin-1 (Ang-1) and S-endoglin (sCD105) and bronchopulmonary dysplasia (BPD) in preterm infants.

METHODS

Sixty-one preterm infants admitted to the neonatal intensive care unit of the study hospital between July 2021 and September 2022 were included. Cord blood was collected after the birth of premature infants. Ang-1 and sCD105 levels were quantified using the vascular endothelial growth factor enzyme-linked immunosorbent assay. Preterm infants were divided into BPD and non-BPD groups, and differences in Ang-1 and sCD105 levels between the two groups were compared. A binary logistic model was used to assess the association between low and high levels Ang-1 and BPD in preterm infants.

RESULTS

In the study, there were 20 preterm infants with BPD (32.8%) and 41 preterm infants with non-BPD (67.2%). Ang-1 concentration levels were lower in the BPD group than in the non-BPD group (7105.43 (5617.01-8523.00) pg/ml vs. 10488.03 (7946.19-15962.77) pg/ml, P = 0.027). However, the sCD105 concentration levels were not significantly different between the BPD and non-BPD groups (P = 0.246). A median Ang-1 concentration of 8800.40 pg/ml was calculated. Logistic regression analysis showed that after adjusting for gestational age, birth weight, and maternal prenatal steroid hormone application, the odds ratio (OR) was 8.577 for the risk of BPD in preterm infants with Ang-1 concentrations of ≤ 8800.40 pg/ml compared to those with Ang-1 concentrations of > 8800.40 pg/ml (OR: 8.577, 95% confidence interval: 1.265-58.155, P = 0.028).

CONCLUSION

Our study indicated that Ang-1 levels in the cord blood of preterm infants may be associated the risk of BPD. In the future, we will continue to conduct study with large samples.

Exploring the relation between patent ductus arteriosus and bronchopulmonary dysplasia: Insights from national inpatient sample

Background

Bronchopulmonary dysplasia (BPD) poses a challenge in neonatal care. Previous literature recommended a hypothetical role for patent ductus arteriosus (PDA) in the development of BPD. This study explores the possible link between PDA and BPD, aiming to illuminate demographic and clinical factors influencing BPD development within the context of PDA.

Methods

This retrospective cohort analysis employed data from the National Inpatient Sample (NIS) spanning from 2016 to 2020. The study focused on patients diagnosed with PDA and BPD, identified through International Classification of Diseases 10th Revision codes Q250 and P271, respectively. Utilizing STATA ×15, descriptive and inferential statistics, encompassing univariate and multivariate regression analyses, were conducted to examine the association between PDA and BPD.

Results

A total of 9737 patients were included: 5133 without PDA and 4604 with PDA. The mortality rate was significantly higher among patients with PDA (3.80%) compared to those without PDA (2.53%) (P < 0.0001). Univariate and multivariate regression analyses identified a significant association between PDA and BPD, with odds ratios of 14.62 and 2.43, respectively (both P < 0.0001). BPD patients with PDA also exhibited a significantly higher prevalence of extremely preterm birth (76.24% vs. 58.31%, P < 0.0001) and extremely low birth weight (65.57% vs. 42.70%, P < 0.0001) compared to BPD patients without PDA. In addition, significant associations were observed between BPD and factors such as preterm birth category, neonatal sepsis, race, hospital status, and region (all P < 0.0001).

Conclusions

This research confirms the connection between PDA and BPD, stressing the importance of continued investigation and prospective studies. The findings highlight the need to consider several factors in understanding the etiology of the disease, which could lead to more targeted interventions and improved patient care.

PC (16:0/14:0) ameliorates hyperoxia-induced bronchopulmonary dysplasia by upregulating claudin-1 and promoting alveolar type II cell repair

Bronchopulmonary dysplasia (BPD) remains a significant challenge in neonatal care, the pathogenesis of which potentially involves altered lipid metabolism. Given the critical role of lipids in lung development and the injury response, we hypothesized that specific lipid species could serve as therapeutic agents in BPD. This study aimed to investigate the role of the lipid Phosphatidylcholine (PC) (16:0/14:0) in modulating BPD pathology and to elucidate its underlying mechanisms of action. Our approach integrated in vitro and in vivo methodologies to assess the effects of PC (16:0/14:0) on the histopathology, cellular proliferation, apoptosis, and molecular markers in lung tissue. In a hyperoxia-induced BPD rat model, we observed a reduction in alveolar number and an enlargement in alveolar size, which were ameliorated by PC (16:0/14:0) treatment. Correspondingly, in BPD cell models, PC (16:0/14:0) intervention led to increased cell viability, enhanced proliferation, reduced apoptosis, and elevated surfactant protein C (SPC) expression. RNA sequencing revealed significant gene expression differences between BPD and PC (16:0/14:0) treated groups, with a particular focus on Cldn1 (encoding claudin 1), which was significantly enriched in our analysis. Our findings suggest that PC (16:0/14:0) might protect against hyperoxia-induced alveolar type II cell damage by upregulating CLDN1 expression, potentially serving as a novel therapeutic target for BPD. This study not only advances our understanding of the role of lipids in BPD pathogenesis, but also highlights the significance of PC (16:0/14:0) in the prevention and treatment of BPD, offering new avenues for future research and therapeutic development.

Brain Network Characterization of Preterm Infants With Bronchopulmonary Dysplasia

BACKGROUND

Bronchopulmonary dysplasia (BPD) affects the microstructure of white matter in preterm infants, but its influence on the changes of the brain structural network has not been elaborated. This study aims to investigate the connectivity characteristics of the brain structural network of BPD by using diffusion tensor imaging.

METHODS

Thirty-three infants with BPD and 26 infants without BPD were enrolled in this study. Brain structural networks were constructed utilizing automated anatomic labeling mapping by tracing the fibers between each pair of regions in individual space. We calculated network metrics such as global efficiency, local efficiency, clustering coefficients, characteristic path length, and small-worldness. Then we compared the network metrics of these infants with those of 57 healthy term infants of comparable postmenstrual age at magnetic resonance imaging scan. Finally, network-based statistics was used to analyze the differences in brain network connectivity between the groups with and without BPD.

RESULTS

Preterm infants with BPD had higher local efficiency and clustering coefficient, lower global efficiency, and longer characteristic path length. Also, preterm infants with BPD had decreased strength of limbic connections mainly in four brain regions: the left lingual gyrus, the left calcarine fissure and surrounding cortex, the right parahippocampal gyrus, and the left precuneus.

CONCLUSIONS

Our findings suggest that preterm infants with BPD have lower network integration and higher segregation at term-equivalent age, which may reflect a compensatory mechanism. In addition, BPD affects brain regions involved in visual as well as cognitive functions; these findings provide a new approach to diagnose potential brain damage in preterm infants with BPD.

Deficiency of Secreted Phosphoprotein 1 Alleviates Hyperoxia-induced Bronchopulmonary Dysplasia in Neonatal Mice

Bronchopulmonary dysplasia (BPD) is a common chronic lung disorder characterized by impaired proximal airway and bronchoalveolar development in premature births. Secreted phosphoprotein 1 (SPP1) is involved in lung development and lung injury events, while its role was not explored in BPD. For establishing the in vivo models of BPD, a mouse model of hyperoxia-induced lung injury was generated by exposing neonatal mice to hyperoxia for 7 days after birth. Alveolar myofibroblasts (AMYFs) were treated with hyperoxia to establish the in vitro models of BPD. Based on the scRNA-seq analysis of lungs of mice housed under normoxia or hyperoxia conditions, mouse macrophages and fibroblasts were main different cell clusters between the two groups, and differentially expressed genes in fibroblasts were screened. Further GO and KEGG enrichment analysis revealed that these differentially expressed genes were mainly enriched in the pathways related to cell proliferation, apoptosis as well as the PI3K-AKT and ERK/MAPK pathways. SPP1 was found up-regulated in the lung tissues of hyperoxia mice. We also demonstrated the up-regulation of SPP1 in the BPD patients, the mouse model of hyperoxia-induced lung injury, and hyperoxia-induced cells. SPP1 deficiency was revealed to reduce the hyperoxia-induced apoptosis, oxidative stress and inflammation and increase the viability of AMYFs. In the mouse model of hyperoxia induced lung injury, SPP1 deficiency was demonstrated to reverse the hyperoxia-induced alveolar growth disruption, oxidative stress and inflammation. Overall, SPP1 exacerbates BPD progression in vitro and in vivo by regulating oxidative stress and inflammatory response via the PI3K-AKT and ERK/MAPK pathways, which might provide novel therapeutic target for BPD therapy.

Grimm S, Coarfa C, Theis F, Simon LM, Shivanna B. Leveraging Integrated RNA Sequencing to Decipher Adrenomedullin's Protective Mechanisms in Experimental Bronchopulmonary Dysplasia

Bronchopulmonary dysplasia (BPD) is a chronic lung disease commonly affecting premature infants, with limited therapeutic options and increased long-term consequences. Adrenomedullin (Adm), a proangiogenic peptide hormone, has been found to protect rodents against experimental BPD. This study aims to elucidate the molecular and cellular mechanisms through which Adm influences BPD pathogenesis using a lipopolysaccharide (LPS)-induced model of experimental BPD in mice. Bulk RNA sequencing of Adm-sufficient (wild-type or Adm+/+) and Adm-haplodeficient (Adm+/-) mice lungs, integrated with single-cell RNA sequencing data, revealed distinct gene expression patterns and cell type alterations associated with Adm deficiency and LPS exposure. Notably, computational integration with cell atlas data revealed that Adm-haplodeficient mouse lungs exhibited gene expression signatures characteristic of increased inflammation, natural killer (NK) cell frequency, and decreased endothelial cell and type II pneumocyte frequency. Furthermore, in silico human BPD patient data analysis supported our cell type frequency finding, highlighting elevated NK cells in BPD infants. These results underscore the protective role of Adm in experimental BPD and emphasize that it is a potential therapeutic target for BPD infants with an inflammatory phenotype.

Right ventricular function indices and platelet parameters for early prediction value of bronchopulmonary dysplasia: a retrospective study

BACKGROUND

To examine the value of early echocardiographic indices for the right ventricular function combined with platelet(PLT) parameters for predicting bronchopulmonary dysplasia (BPD) in preterm infants.

METHODS

This retrospective study included infants with gestational age (GA) below 32 weeks, who were admitted to the neonatal intensive care unit(NICU). The detection rate of tricuspid regurgitation jet velocity (TRVJ), ventricular septal flattening, pulmonary artery widening, right ventricular dilation, and right atrial enlargement on the 7th day of life (DOL 7) were compared between BPD and non-BPD infants. Echocardiographic indices of the right ventricular function including tricuspid annular plane systolic excursion (TAPSE) and right ventricular index of myocardial performance (RIMP) were measured on 1 day of life (DOL 1)、on DOL 7 and on 14 day of life (DOL 14) respectively. The PLT parameters including the PLT count, mean platelet volume (MPV), platelet hematocrit (PCT) level, and platelet distribution width (PDW) were measured on the DOL 1,DOL 7, and DOL 14. Multivariate logistic regression was used to analyze the relationship between these parameters and BPD. Receiver operating characteristic curve analysis was performed to assess the predictive value of the right ventricular function indices and PLT parameters for BPD.

RESULTS

A total of 220 preterm infants were included in this study, and of these, 85 infants developed BPD among them. The RIMP of the BPD group on DOL 14 was higher than that of the non-BPD group (P < 0.05). The TAPSE of the BPD group on DOL 14 was lower than that of the non-BPD group (P < 0.05). The PLT count of the BPD group on DOL 1 was lower than that of the non-BPD group (P < 0.05), and the MPV of the BPD group on DOL 1 was higher than that of the non-BPD group (P < 0.05). Using multivariate logistic regression, GA、invasive mechanical ventilation duration ≥ 7 days、 PLT、 MPV、 TAPSE and RIMP were found to be independent risk factors for BPD. The area under the receiver operating characteristic curve was 0.846 (95CI: 0.794∼0.899), which improved when using right ventricular function indices combined with platelet parameters.

CONCLUSION

TAPSE and RIMP combined with PLT count and MPV can help identify preterm infants at an increased risk of developing BPD.

Mitochondrial DNA mutations in extremely preterm infants with bronchopulmonary dysplasia

Bronchopulmonary dysplasia (BPD) is a serious chronic lung disease affecting extremely preterm infants. While mitochondrial dysfunction has been investigated in various medical conditions, limited research has explored mitochondrial DNA (mtDNA) gene mutations, specifically in BPD. This study aimed to evaluate mitochondrial mtDNA gene mutations in extremely preterm infants with BPD. In this prospective observational study, we enrolled a cohort of extremely preterm infants diagnosed with BPD. Clinical data were collected to provide comprehensive patient profiles. Peripheral blood mononuclear cells were isolated from whole-blood samples obtained within a defined timeframe. Subsequently, mtDNA extraction and sequencing using next-generation sequencing technology were performed to identify mtDNA gene mutations. Among the cohort of ten extremely preterm infants with BPD, mtDNA sequencing revealed the presence of mutations in seven patients, resulting in a total of twenty-one point mutations. Notably, many of these mutations were identified in loci associated with critical components of the respiratory chain complexes, vital for proper mitochondrial function and cellular energy production. This pilot study provides evidence of mtDNA point mutations in a subset of extremely preterm infants with BPD. These findings suggest a potential association between mitochondrial dysfunction and the pathogenesis of BPD. Further extensive investigations are warranted to unravel the mechanisms underlying mtDNA mutations in BPD.

Respiratory polygraphy in children with bronchopulmonary dysplasia: a retrospective study

BACKGROUND

Periodic assessment of the need for oxygen supplementation and/or mechanical ventilation in children with severe bronchopulmonary dysplasia (BPD) is crucial. The aim of the study was to analyze the indications and results of respiratory polygraphies (RP) performed in preterm infants with BPD followed at a tertiary university hospital.

METHODS

All subjects <5-year-old with BPD who had a RP between September and February 2018 were included. The indications and results of RP and consequent medical management were analyzed.

RESULTS

Fourteen infants (9 females, mean gestational age 27.6±3.3 weeks) underwent a RP at mean age of 26.4±19.4 months. Five subjects were evaluated for the need of long-term respiratory support (RS), 3 started continuous positive airway pressure (CPAP), 2 were weaned from RS. Four subjects underwent RP for suspected obstructive sleep apnea (OSA), one started on CPAP. Central apnea syndrome (CSA) was confirmed in 2 subjects and one was started on non-invasive ventilation. RP allowed safe tracheostomy decannulation in 2 subjects. Finally, RP was normal in one subject who had a brief resolved unexplained event.

CONCLUSIONS

RP represents an important tool for the evaluation of children with BPD and leads to important therapeutic decisions.

Quality Improvement Initiative Enhances Outpatient Pediatric Pulmonology Follow-up for Premature Infants with Bronchopulmonary Dysplasia

Introduction

Bronchopulmonary dysplasia (BPD) is a chronic lung disorder affecting many premature infants. Infants with BPD have higher hospital readmission rates due to respiratory-related morbidity. We aimed to increase the rates of outpatient pulmonary follow-up and attendance of premature babies with moderate and severe BPD to above 85% within 6 months.

Methods

We conducted a quality improvement project at Yale New Haven Children's Hospital. Key interventions included developing a BPD clinical pathway integrated into the electronic medical record to assist providers in correctly classifying BPD severity, assigning the appropriate International Classification of Diseases, 10th Revision code (P27.1), and providing standardized treatment options. The outcome measures included correct diagnosis and classification of BPD, the percentage of patients with BPD scheduled for pediatric pulmonology appointments within 45 days, and the percentage attending those appointments.

Results

There were 226 patients in our study, including 85 in the baseline period. Correct diagnosis of BPD increased from 49% to 95%, the percentage of scheduled appointments increased from 71.9% to 100%, and the percentage of appointments attended increased from 55.6% to 87.1%.

Conclusions

Our quality improvement initiative improved the accuracy of diagnosis, severity classification, and outpatient pulmonary follow-up of children with moderate and severe BPD.

Retrospective study of serial polysomnograms of bronchopulmonary dysplasia patients with oxygen dependence

INTRODUCTION

This retrospective study describes characteristics of serial polysomnograms (PSGs) of BPD patients on home oxygen therapy and describes PSG parameters associated with discontinuation of supplemental oxygen.

METHODS

A single-center study was performed at Children's Hospital Los Angeles, where serial PSGs for 44 patients with BPD infants discharged on home oxygen therapy were extracted for maximum of five PSGs or until oxygen discontinuation. Clinical and polysomnography data was collected. Characteristics of PSG1 were compared amongst the patients who were weaned from oxygen after PSG2 and PSG3.

RESULTS

Of 44 patients, 68.2% of patients were males with median birth gestational age of 26 weeks (IQR: 24.6-28.1), median birthweight of 777.5 g (IQR: 632.5-1054 g) and 77.3% of the cohort had severe BPD. A total of 138 PSGs were studied between all 44 patients serially. When comparing PSG1 and PSG2 parameters, statistically significant improvement was noted in multiple parameters. Median baseline SpO2, peak RR, and average PETCO2 were found to be potential predictors of prolonged oxygen use. Gestational age and birth weight were not associated with prolonged oxygen use after PSG3. The median age of oxygen discontinuation was calculated to be about 2 years of age.

CONCLUSIONS

The severity of hypoxia and tachypnea on initial infant PSG are associated with prolonged oxygen therapy past 2 years of age. Growth and development of lungs with maturation of control of breathing help improve these parameters over time regardless of BPD severity. The study may inform discussions between providers and parents for patients discharged home on oxygen therapy.

Improving early diagnosis of bronchopulmonary dysplasia

INTRODUCTION

Bronchopulmonary disease (BPD) is associated with long-term neurodevelopmental and cardiorespiratory complications, often requiring significant use of resources. To reduce this healthcare burden, it is essential that those at high risk of BPD are identified early so that strategies are introduced to prevent disease progression. Our aim was to discuss potential methods for improving early diagnosis in the first week after birth.

AREAS COVERED

A narrative review was undertaken. The search strategy involved searching PubMed, Embase and Cochrane databases from 1967 to 2024. The results of potential biomarkers and imaging modes are discussed. Furthermore, the value of scoring systems is explored.

EXPERT OPINION

BPD occurs as a result of disruption to pulmonary vascular and alveolar development, thus abnormal levels of factors regulating those processes are promising avenues to explore with regard to early detection of high-risk infants. Data from twin studies suggests genetic factors can be attributed to 82% of the observed difference in moderate to severe BPD, but large genome-wide studies have yielded conflicting results. Comparative studies are required to determine which biomarker or imaging mode may most accurately diagnose early BPD development. Models which include the most predictive factors should be evaluated going forward.

[Impact of different angles of pulmonary surfactant administration on bronchopulmonaryplasia and intracranial hemorrhage in preterm infants: a prospective randomized controlled study]

OBJECTIVES

To investigate the effects of different angles of pulmonary surfactant (PS) administration on the incidence of bronchopulmonary dysplasia and intracranial hemorrhage in preterm infants.

METHODS

A prospective study was conducted on 146 preterm infants (gestational age <32 weeks) admitted to the Department of Neonatology, Provincial Hospital Affiliated to Anhui Medical University from January 2019 to May 2023. The infants were randomly assigned to different angles for injection of pulmonary surfactant groups: 0° group (34 cases), 30° group (36 cases), 45° group (38 cases), and 60° group (38 cases). Clinical indicators and outcomes were compared among the groups.

RESULTS

The oxygenation index was lower in the 60° group compared with the other three groups, with shorter invasive ventilation time and oxygen use time, and a lower incidence of bronchopulmonary dysplasia than the other three groups (P<0.05). The incidence of intracranial hemorrhage was lower in the 60° group compared to the 0° group (P<0.05). The cure rate in the 60° group was higher than that in the 0° group and the 30° group (P<0.05).

CONCLUSIONS

The clinical efficacy of injection of pulmonary surfactant at a 60° angle is higher than other angles, reducing the incidence of intracranial hemorrhage and bronchopulmonary dysplasia in preterm infants.

Corticosteroids for the prevention and treatment of bronchopulmonary dysplasia: an overview of systematic reviews

BACKGROUND

Bronchopulmonary dysplasia (BPD) remains an important complication of prematurity. Pulmonary inflammation plays a central role in the pathogenesis of BPD, explaining the rationale for investigating postnatal corticosteroids. Multiple systematic reviews (SRs) have summarised the evidence from numerous randomised controlled trials (RCTs) investigating different aspects of administrating postnatal corticosteroids. Besides beneficial effects on the outcome of death or BPD, potential short- and long-term harms have been reported.

OBJECTIVES

The primary objective of this overview was to summarise and appraise the evidence from SRs regarding the efficacy and safety of postnatal corticosteroids in preterm infants at risk of developing BPD.

METHODS

We searched the Cochrane Database of Systematic Reviews, MEDLINE, Embase, CINAHL, and Epistemonikos for SRs in April 2023. We included all SRs assessing any form of postnatal corticosteroid administration in preterm populations with the objective of ameliorating pulmonary disease. All regimens and comparisons were included. Two review authors independently checked the eligibility of the SRs comparing corticosteroids with placebo, and corticosteroids with different routes of administration and regimens. The included outcomes, considered key drivers in the decision to administer postnatal corticosteroids, were the composite outcome of death or BPD at 36 weeks' postmenstrual age (PMA), its individual components, long-term neurodevelopmental sequelae, sepsis, and gastrointestinal tract perforation. We independently assessed the methodological quality of the included SRs by using AMSTAR 2 (A Measurement Tool to Assess Systematic Reviews) and ROBIS (Risk Of Bias In Systematic reviews) tools. We assessed the certainty of the evidence using GRADE. We provided a narrative description of the characteristics, methodological quality, and results of the included SRs.

MAIN RESULTS

We included nine SRs (seven Cochrane, two non-Cochrane) containing 87 RCTs, 1 follow-up study, and 9419 preterm infants, investigating the effects of postnatal corticosteroids to prevent or treat BPD. The quality of the included SRs according to AMSTAR 2 varied from high to critically low. Risk of bias according to ROBIS was low. The certainty of the evidence according to GRADE ranged from very low to moderate. Early initiated systemic dexamethasone (< seven days after birth) likely has a beneficial effect on death or BPD at 36 weeks' PMA (risk ratio (RR) 0.88, 95% confidence interval (CI) 0.81 to 0.95; number needed to treat for an additional beneficial outcome (NNTB) 16, 95% CI 10 to 41; I2 = 39%; 17 studies; 2791 infants; moderate-certainty evidence) and on BPD at 36 weeks' PMA (RR 0.72, 95% CI 0.63 to 0.82; NNTB 13, 95% CI 9 to 21; I2 = 39%; 17 studies; 2791 infants; moderate-certainty evidence). Early initiated systemic hydrocortisone may also have a beneficial effect on death or BPD at 36 weeks' PMA (RR 0.90, 95% CI 0.82 to 0.99; NNTB 18, 95% CI 9 to 594; I2 = 43%; 9 studies; 1376 infants; low-certainty evidence). However, these benefits are likely accompanied by harmful effects like cerebral palsy or neurosensory disability (dexamethasone) or gastrointestinal perforation (both dexamethasone and hydrocortisone). Late initiated systemic dexamethasone (≥ seven days after birth) may have a beneficial effect on death or BPD at 36 weeks' PMA (RR 0.75, 95% CI 0.67 to 0.84; NNTB 5, 95% CI 4 to 9; I2 = 61%; 12 studies; 553 infants; low-certainty evidence), mostly contributed to by a beneficial effect on BPD at 36 weeks' PMA (RR 0.76, 95% CI 0.66 to 0.87; NNTB 6, 95% CI 4 to 13; I2 = 14%; 12 studies; 553 infants; low-certainty evidence). No harmful side effects were shown in the outcomes chosen as key drivers to the decision to start or withhold late systemic dexamethasone. No effects, either beneficial or harmful, were found in the subgroup meta-analyses of late hydrocortisone studies. Early initiated inhaled corticosteroids probably have a beneficial effect on death and BPD at 36 weeks' PMA (RR 0.86, 95% CI 0.75 to 0.99; NNTB 19, 95% CI not applicable; I2 = 0%; 6 studies; 1285 infants; moderate-certainty evidence), with no apparent adverse effects shown in the SRs. In contrast, late initiated inhaled corticosteroids do not appear to have any benefits or harms. Endotracheal instillation of corticosteroids (budesonide) with surfactant as a carrier likely has a beneficial effect on death or BPD at 36 weeks' PMA (RR 0.60, 95% CI 0.49 to 0.74; NNTB 4, 95% CI 3 to 6; I2 = 0%; 2 studies; 381 infants; moderate-certainty evidence) and on BPD at 36 weeks' PMA. No evidence of harmful effects was found. There was little evidence for effects of different starting doses or timing of systemic corticosteroids on death or BPD at 36 weeks' PMA, but potential adverse effects were observed for some comparisons. Lowering the dose might result in a more unfavourable balance of benefits and harms. Moderately early initiated systemic corticosteroids, compared with early systemic corticosteroids, may result in a higher incidence of BPD at 36 weeks' PMA. Pulse dosing instead of continuous dosing may have a negative effect on death and BPD at 36 weeks' PMA. We found no differences for the comparisons of inhaled versus systemic corticosteroids.

AUTHORS' CONCLUSIONS

This overview summarises the evidence of nine SRs investigating the effect of postnatal corticosteroids in preterm infants at risk for BPD. Late initiated (≥ seven days after birth) systemic administration of dexamethasone is considered an effective intervention to reduce the risk of BPD in infants with a high risk profile for BPD, based on a favourable balance between benefits and harms. Endotracheal instillation of corticosteroids (budesonide) with surfactant as a carrier is a promising intervention, based on the beneficial effect on desirable outcomes without (so far) negative side effects. Pending results of ongoing large, multicentre RCTs investigating both short- and long-term effects, endotracheal instillation of corticosteroids (budesonide) with surfactant as a carrier is not appropriate for clinical practice at present. Early initiated (< seven days after birth) systemic dexamethasone and hydrocortisone and late initiated (≥ seven days after birth) hydrocortisone are considered ineffective interventions, because of an unfavourable balance between benefits and harms. No conclusions are possible regarding early and late inhaled corticosteroids, as more research is needed.