Inhaled versus systemic corticosteroids for preventing bronchopulmonary dysplasia in ventilated very low birth weight preterm neonates

The Care of Preterm and Term Newborns with Respiratory Conditions: A Systematic Synthesis of Evidence from Low- and Middle-Income Countries

INTRODUCTION

Neonatal respiratory conditions are leading causes of mortality and morbidity during the neonatal period. This review evaluated 11 management interventions for respiratory distress syndrome (RDS), apnoea of prematurity (AOP), meconium aspiration syndrome (MAS), transient tachypnea of the newborn (TTN), as well as bronchopulmonary dysplasia (BPD) as a potential complication from respiratory care in low- and middle-income countries (LMICs).

METHODS

Two different methodological approaches were completed: (1) updating outdated reviews and pooling all LMIC studies and (2) re-analysis of LMIC studies from up-to-date reviews. Review updates were conducted between October 2022 and February 2023 and followed systematic methodology. A total of 50 studies were included across four review updates and seven review re-analyses.

RESULTS

Findings indicate that bubble CPAP (RR 0.74, 95% CI: 0.58-0.96) and prophylactic CPAP (RR 0.39, 95% CI: 0.26-0.57) for RDS reduced the risk of treatment failure compared to other ventilation types or supportive care, respectively. Postnatal corticosteroids reduced BPD assessed as oxygen requirement at 36 weeks' postmenstrual age (RR 0.56, 95% CI: 0.41-0.77). All other outcomes were found to be non-significant across remaining interventions.

CONCLUSIONS

Our findings indicate that prophylactic and bubble CPAP may provide some benefit by reducing treatment failure compared to other pressure sources. The safety and efficacy of other management interventions for RDS, AOP, BPD, MAS, and TTN remains uncertain given limited evaluations in LMICs. Future research should conduct adequately powered trials in underrepresented LMIC regions, investigate long-term outcomes, and evaluate cost-effectiveness.

INTRODUCTION

Neonatal respiratory conditions are leading causes of mortality and morbidity during the neonatal period. This review evaluated 11 management interventions for respiratory distress syndrome (RDS), apnoea of prematurity (AOP), meconium aspiration syndrome (MAS), transient tachypnea of the newborn (TTN), as well as bronchopulmonary dysplasia (BPD) as a potential complication from respiratory care in low- and middle-income countries (LMICs).

METHODS

Two different methodological approaches were completed: (1) updating outdated reviews and pooling all LMIC studies and (2) re-analysis of LMIC studies from up-to-date reviews. Review updates were conducted between October 2022 and February 2023 and followed systematic methodology. A total of 50 studies were included across four review updates and seven review re-analyses.

RESULTS

Findings indicate that bubble CPAP (RR 0.74, 95% CI: 0.58-0.96) and prophylactic CPAP (RR 0.39, 95% CI: 0.26-0.57) for RDS reduced the risk of treatment failure compared to other ventilation types or supportive care, respectively. Postnatal corticosteroids reduced BPD assessed as oxygen requirement at 36 weeks' postmenstrual age (RR 0.56, 95% CI: 0.41-0.77). All other outcomes were found to be non-significant across remaining interventions.

CONCLUSIONS

Our findings indicate that prophylactic and bubble CPAP may provide some benefit by reducing treatment failure compared to other pressure sources. The safety and efficacy of other management interventions for RDS, AOP, BPD, MAS, and TTN remains uncertain given limited evaluations in LMICs. Future research should conduct adequately powered trials in underrepresented LMIC regions, investigate long-term outcomes, and evaluate cost-effectiveness.

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.

Prescribing practices of inhaled corticosteroids for premature infants in the neonatal intensive care unit

OBJECTIVE

Despite limited safety and efficacy data, inhaled corticosteroids (ICS) are prescribed to premature infants in the neonatal intensive care unit (NICU). We examined contemporary use and risk factors for ICS use in the NICU.

STUDY DESIGN

Infants <33 weeks gestational age and <1500 gm birth weight discharged from Pediatrix Medical Group NICUs between 2010 and 2020 were included. We evaluated the association between ICS prescription and clinical characteristics using univariable and multivariable logistic regression.

RESULTS

Of 74,123 infants from 308 NICUs, 9253 (12.5%) were prescribed ICS: budesonide, fluticasone, or beclomethasone. Diagnosis of bronchopulmonary dysplasia (BPD), earlier gestational age, male sex, longer mechanical ventilation, oxygen support, and systemic steroids were independent risk factors for ICS prescription.

CONCLUSIONS

Use of ICS is common in many NICUs and is associated with a diagnosis of BPD and healthcare utilization. Prospective trials are needed to establish the safety, efficacy, and optimal indication in this vulnerable population.

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.

Interventions for reducing late-onset sepsis in neonates: an umbrella review

OBJECTIVES

Neonatal sepsis is one of the leading causes of neonatal deaths in neonatal intensive care units. Hence, it is essential to review the evidence from systematic reviews on interventions for reducing late-onset sepsis (LOS) in neonates.

METHODS

PubMed and the Cochrane Central were searched from inception through August 2020 without any language restriction. Cochrane reviews of randomized clinical trials (RCTs) assessing any intervention in the neonatal period and including one or more RCTs reporting LOS. Two authors independently performed screening, data extraction, assessed the quality of evidence using Cochrane Grading of Recommendations Assessment, Development and Evaluation, and assessed the quality of reviews using a measurement tool to assess of multiple systematic reviews 2 tool.

RESULTS

A total of 101 high-quality Cochrane reviews involving 612 RCTs and 193,713 neonates, evaluating 141 interventions were included. High-quality evidence showed a reduction in any or culture-proven LOS using antibiotic lock therapy for neonates with central venous catheters (CVC). Moderate-quality evidence showed a decrease in any LOS with antibiotic prophylaxis or vancomycin prophylaxis for neonates with CVC, chlorhexidine for skin or cord care, and kangaroo care for low birth weight babies. Similarly, moderate-quality evidence showed reduced culture-proven LOS with intravenous immunoglobulin prophylaxis for preterm infants and probiotic supplementation for very low birth weight (VLBW) infants. Lastly, moderate-quality evidence showed a reduction in fungal LOS with the use of systemic antifungal prophylaxis in VLBW infants.

CONCLUSIONS

The overview summarizes the evidence from the Cochrane reviews assessing interventions for reducing LOS in neonates, and can be utilized by clinicians, researchers, policymakers, and consumers for decision-making and translating evidence into clinical practice.

European Consensus Guidelines on the Management of Respiratory Distress Syndrome: 2022 Update

Respiratory distress syndrome (RDS) care pathways evolve slowly as new evidence emerges. We report the sixth version of "European Guidelines for the Management of RDS" by a panel of experienced European neonatologists and an expert perinatal obstetrician based on available literature up to end of 2022. Optimising outcome for babies with RDS includes prediction of risk of preterm delivery, appropriate maternal transfer to a perinatal centre, and appropriate and timely use of antenatal steroids. Evidence-based lung-protective management includes initiation of non-invasive respiratory support from birth, judicious use of oxygen, early surfactant administration, caffeine therapy, and avoidance of intubation and mechanical ventilation where possible. Methods of ongoing non-invasive respiratory support have been further refined and may help reduce chronic lung disease. As technology for delivering mechanical ventilation improves, the risk of causing lung injury should decrease, although minimising time spent on mechanical ventilation by targeted use of postnatal corticosteroids remains essential. The general care of infants with RDS is also reviewed, including emphasis on appropriate cardiovascular support and judicious use of antibiotics as being important determinants of best outcome. We would like to dedicate this guideline to the memory of Professor Henry Halliday who died on November 12, 2022.These updated guidelines contain evidence from recent Cochrane reviews and medical literature since 2019. Strength of evidence supporting recommendations has been evaluated using the GRADE system. There are changes to some of the previous recommendations as well as some changes to the strength of evidence supporting recommendations that have not changed. This guideline has been endorsed by the European Society for Paediatric Research (ESPR) and the Union of European Neonatal and Perinatal Societies (UENPS).

Late (≥ 7 days) inhaled corticosteroids to reduce bronchopulmonary dysplasia in preterm infants

BACKGROUND

Bronchopulmonary dysplasia (BPD), defined as oxygen dependence at 36 weeks' postmenstrual age (PMA), remains an important complication of prematurity. Pulmonary inflammation plays a central role in the pathogenesis of BPD. Attenuating pulmonary inflammation with postnatal systemic corticosteroids reduces the incidence of BPD in preterm infants but may be associated with an increased risk of adverse neurodevelopmental outcomes. Local administration of corticosteroids via inhalation may be an effective and safe alternative.

OBJECTIVES

To assess the benefits and harms of inhaled corticosteroids versus placebo, initiated between seven days of postnatal life and 36 weeks' postmenstrual age, to preterm infants at risk of developing bronchopulmonary dysplasia.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, CINAHL, and three trials registries to August 2022. We searched conference proceedings and the reference lists of retrieved articles for additional studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing inhaled corticosteroids to placebo, started between seven days' postnatal age (PNA) and 36 weeks' PMA, in infants at risk of BPD. We excluded trials investigating systemic corticosteroids versus inhaled corticosteroids.

DATA COLLECTION AND ANALYSIS

We collected data on participant characteristics, trial methodology, and inhalation regimens. The primary outcomes were mortality, BPD, or both at 36 weeks' PMA. Secondary outcomes included short-term respiratory outcomes (mortality or BPD at 28 days' PNA, failure to extubate, total days of mechanical ventilation and oxygen use, and need for systemic corticosteroids) and adverse effects. We contacted the trial authors to verify the validity of extracted data and to request missing data. We analysed all data using Review Manager 5. Where possible, we reported the results of meta-analyses using risk ratios (RRs) and risk differences (RDs) for dichotomous outcomes and mean differences (MDs) for continuous outcomes, along with their 95% confidence intervals (CIs). We analysed ventilated and non-ventilated participants separately. We used the GRADE approach to assess the certainty of the evidence.

MAIN RESULTS

We included seven trials involving 218 preterm infants in this review. We identified no new eligible studies in this update. The evidence is very uncertain regarding whether inhaled corticosteroids affects the combined outcome of mortality or BPD at 36 weeks' PMA (RR 1.10, 95% CI 0.74 to 1.63; RD 0.07, 95% CI -0.21 to 0.34; 1 study, 30 infants; very low-certainty) or its separate components: mortality (RR 3.00, 95% CI 0.35 to 25.78; RD 0.07, 95% CI -0.08 to 0.21; 3 studies, 61 infants; very low-certainty) and BPD (RR 1.00, 95% CI 0.59 to 1.70; RD 0.00, 95% CI -0.31 to 0.31; 1 study, 30 infants; very low-certainty) at 36 weeks' PMA. Inhaled corticosteroids may reduce the need for systemic corticosteroids, but the evidence is very uncertain (RR 0.51, 95% CI 0.26 to 1.00; RD -0.22, 95% CI -0.42 to -0.02; number needed to treat for an additional beneficial outcome 5, 95% CI 2 to 115; 4 studies, 74 infants; very low-certainty). There was a paucity of data on short-term and long-term adverse effects. Despite a low risk of bias in the individual studies, we considered the certainty of the evidence for all comparisons discussed above to be very low, because the studies had few participants, there was substantial clinical heterogeneity between studies, and only three studies reported the primary outcome of this review.

AUTHORS' CONCLUSIONS

Based on the available evidence, we do not know if inhaled corticosteroids initiated from seven days of life in preterm infants at risk of developing BPD reduces mortality or BPD at 36 weeks' PMA. There is a need for larger randomised placebo-controlled trials to establish the benefits and harms of inhaled corticosteroids.

Human breast milk-derived exosomes through inhibiting AT II cell apoptosis to prevent bronchopulmonary dysplasia in rat lung

Human breast milk (HBM) effectively prevents and cures neonatal bronchopulmonary dysplasia (BPD). Exosomes are abundant in breast milk, but the function of HBM‐derived exosomes (HBM‐Exo) in BPD is still unclear. This study was to investigate the role and mechanism of HBM‐Exo in BPD. Overall lung tissue photography and H&E staining showed that HBM‐Exo improved the lung tissue structure collapse, alveolar structure disorder, alveolar septum width, alveolar number reduction and other injuries caused by high oxygen exposure. Immunohistochemical results showed that HBM‐Exo improved the inhibition of cell proliferation and increased apoptosis caused by hyperoxia. qPCR and Western blot results also showed that HBM‐Exo improved the expression of Type II alveolar epithelium (AT II) surface marker SPC. In vivo study, CCK8 and flow cytometry showed that HBM‐Exo improved the proliferation inhibition and apoptosis of AT II cells induced by hyperoxia, qPCR and immunofluorescence also showed that HBM‐Exo improved the down‐regulation of SPC. Further RNA‐Seq results in AT II cells showed that a total of 88 genes were significantly different between the hyperoxia and HBM‐Exo with hyperoxia groups, including 24 up‐regulated genes and 64 down‐regulated genes. KEGG pathway analysis showed the enrichment of IL‐17 signalling pathway was the most significant. Further rescue experiments showed that HBM‐Exo improved AT II cell damage induced by hyperoxia through inhibiting downstream of IL‐17 signalling pathway (FADD), which may be an important mechanism of HBM‐Exo in the prevention and treatment of BPD. This study may provide new approach in the treatment of BPD.

Recent research on the effect of common treatments given in the perinatal period on neurodevelopment in offspring

The perinatal period is the key period for the development of brain and central nervous system, and different events in this period will have a profound influence on brain development. Glucocorticoids, antibiotics, magnesium sulfate, caffeine, pulmonary surfactant, and mild hypothermia treatment are commonly used drugs or treatment methods in the perinatal period and are closely associated with the prognosis of neonatal neurodevelopment. This article reviews the latest research on the effect of perinatal treatments on neonatal neurodevelopment, so as to provide a reference for clinical decision making.

Recent research on the mechanism of mesenchymal stem cells in the treatment of bronchopulmonary dysplasia

Bronchopulmonary dysplasia (BPD) is a chronic lung disease due to impaired pulmonary development and is one of the main causes of respiratory failure in preterm infants. Preterm infants with BPD have significantly higher complication and mortality rates than those without BPD. At present, comprehensive management is the main intervention method for BPD, including reasonable respiratory and circulatory support, appropriate enteral nutrition and parenteral nutrition, application of caffeine/glucocorticoids/surfactants, and out-of-hospital management after discharge. The continuous advances in stem cell medicine in recent years provide new ideas for the treatment of BPD. Various pre-clinical trials have confirmed that stem cell therapy can effectively prevent lung injury and promote lung growth and damage repair. This article performs a comprehensive analysis of the mechanism of mesenchymal stem cells in the treatment of BPD, so as to provide a basis for clinical applications.

Inhaled Pharmacotherapy for Neonates: A Narrative Review

The inhaled route for drug administration in neonates offers several advantages over the systemic routes, since it delivers medications directly to the diseased organ, enabling higher doses locally with less systemic toxicity. Respiratory drugs can be administered in both ventilated and non-ventilated term and preterm infants. This review was carried out using selected literature, with a focus on the most used inhaled pharmacological agents in neonatal care, summarizing, with levels of evidence (LoE), their indications, doses, administration schedules, and main adverse effects. Information is given on several inhaled drugs, namely albuterol, budesonide, ipratropium bromide, sodium cromoglycate, racemic epinephrine, nitric oxide, treprostinil, iloprost, epoprostenol, colistin, rhDNase, hypertonic saline, and calfactant. A summary of the main and most recent published studies on each of these inhaled pharmacological agents is also presented.

Late (≥ 7 days) systemic postnatal corticosteroids for prevention of bronchopulmonary dysplasia in preterm infants

BACKGROUND

Many infants born preterm develop bronchopulmonary dysplasia (BPD), with lung inflammation playing a role. Corticosteroids have powerful anti-inflammatory effects and have been used to treat individuals with established BPD. However, it is unclear whether any beneficial effects outweigh the adverse effects of these drugs.

OBJECTIVES

To examine the relative benefits and adverse effects of late (starting at seven or more days after birth) systemic postnatal corticosteroid treatment for preterm infants with evolving or established BPD.

SEARCH METHODS

We ran an updated search on 25 September 2020 of the following databases: CENTRAL via CRS Web and MEDLINE via OVID. We also searched clinical trials databases and reference lists of retrieved articles for randomised controlled trials (RCTs). We did not include quasi-RCTs.

SELECTION CRITERIA

We selected for inclusion in this review RCTs comparing systemic (intravenous or oral) postnatal corticosteroid treatment versus placebo or no treatment started at seven or more days after birth for preterm infants with evolving or established BPD. We did not include trials of inhaled corticosteroids.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. We extracted and analysed data regarding clinical outcomes that included mortality, BPD, and cerebral palsy. We used the GRADE approach to assess the certainty of evidence.

MAIN RESULTS

Use of the GRADE approach revealed that the certainty of evidence was high for most of the major outcomes considered, except for BPD at 36 weeks for all studies combined and for the dexamethasone subgroup, which were downgraded one level to moderate because of evidence of publication bias, and for the combined outcome of mortality or BPD at 36 weeks for all studies combined and for the dexamethasone subgroup, which were downgraded one level to moderate because of evidence of substantial heterogeneity. We included 23 RCTs (1817 infants); 21 RCTS (1382 infants) involved dexamethasone (one also included hydrocortisone) and two RCTs (435 infants) involved hydrocortisone only. The overall risk of bias of included studies was low; all were RCTs and most trials used rigorous methods. Late systemic corticosteroids overall reduce mortality to the latest reported age (risk ratio (RR) 0.81, 95% confidence interval (CI) 0.66 to 0.99; 21 studies, 1428 infants; high-certainty evidence). Within the subgroups by drug, neither dexamethasone (RR 0.85, 95% CI 0.66 to 1.11; 19 studies, 993 infants; high-certainty evidence) nor hydrocortisone (RR 0.74, 95% CI 0.54 to 1.02; 2 studies, 435 infants; high-certainty evidence) alone clearly reduce mortality to the latest reported age. We found little evidence for statistical heterogeneity between the dexamethasone and hydrocortisone subgroups (P = 0.51 for subgroup interaction). Late systemic corticosteroids overall probably reduce BPD at 36 weeks' postmenstrual age (PMA) (RR 0.89, 95% CI 0.80 to 0.99; 14 studies, 988 infants; moderate-certainty evidence). Dexamethasone probably reduces BPD at 36 weeks' PMA (RR 0.76, 95% CI 0.66 to 0.87; 12 studies, 553 infants; moderate-certainty evidence), but hydrocortisone does not (RR 1.10, 95% CI 0.92 to 1.31; 2 studies, 435 infants; high-certainty evidence) (P < 0.001 for subgroup interaction). Late systemic corticosteroids overall probably reduce the combined outcome of mortality or BPD at 36 weeks' PMA (RR 0.85, 95% CI 0.79 to 0.92; 14 studies, 988 infants; moderate-certainty evidence). Dexamethasone probably reduces the combined outcome of mortality or BPD at 36 weeks' PMA (RR 0.75, 95% CI 0.67 to 0.84; 12 studies, 553 infants; moderate-certainty evidence), but hydrocortisone does not (RR 0.98, 95% CI 0.88 to 1.09; 2 studies, 435 infants; high-certainty evidence) (P < 0.001 for subgroup interaction). Late systemic corticosteroids overall have little to no effect on cerebral palsy (RR 1.17, 95% CI 0.84 to 1.61; 17 studies, 1290 infants; high-certainty evidence). We found little evidence for statistical heterogeneity between the dexamethasone and hydrocortisone subgroups (P = 0.63 for subgroup interaction). Late systemic corticosteroids overall have little to no effect on the combined outcome of mortality or cerebral palsy (RR 0.90, 95% CI 0.76 to 1.06; 17 studies, 1290 infants; high-certainty evidence). We found little evidence for statistical heterogeneity between the dexamethasone and hydrocortisone subgroups (P = 0.42 for subgroup interaction). Studies had few participants who were not intubated at enrolment; hence, it is not possible to make any meaningful comments on the effectiveness of late corticosteroids in preventing BPD in non-intubated infants, including those who might in the present day be supported by non-invasive techniques such as nasal continuous positive airway pressure or high-flow nasal cannula oxygen/air mixture, but who might still be at high risk of later BPD. Results of two ongoing studies are awaited.

AUTHORS' CONCLUSIONS

Late systemic postnatal corticosteroid treatment (started at seven days or more after birth) reduces the risks of mortality and BPD, and the combined outcome of mortality or BPD, without evidence of increased cerebral palsy. However, the methodological quality of studies determining long-term outcomes is limited, and no studies were powered to detect increased rates of important adverse long-term neurodevelopmental outcomes. This review supports the use of late systemic corticosteroids for infants who cannot be weaned from mechanical ventilation. The role of late systemic corticosteroids for infants who are not intubated is unclear and needs further investigation. Longer-term follow-up into late childhood is vital for assessment of important outcomes that cannot be assessed in early childhood, such as effects of late systemic corticosteroid treatment on higher-order neurological functions, including cognitive function, executive function, academic performance, behaviour, mental health, motor function, and lung function. Further RCTs of late systemic corticosteroids should include longer-term survival free of neurodevelopmental disability as the primary outcome.

The Intertemporal Role of Respiratory Support in Improving Neonatal Outcomes: A Narrative Review

Defining improvements in healthcare can be challenging due to the need to assess multiple outcomes and measures. In neonates, although progress in respiratory support has been a key factor in improving survival, the same degree of improvement has not been documented in certain outcomes, such as bronchopulmonary dysplasia. By exploring the evolution of neonatal respiratory care over the last 60 years, this review highlights not only the scientific advances that occurred with the application of invasive mechanical ventilation but also the weakness of the existing knowledge. The contributing role of non-invasive ventilation and less-invasive surfactant administration methods as well as of certain pharmacological therapies is also discussed. Moreover, we analyze the cost-benefit of neonatal care-respiratory support and present future challenges and perspectives.

Clinical Characteristics and Outcomes Until 2 Years of Age in Preterm Infants With Typical Chest Imaging Findings of Bronchopulmonary Dysplasia: A Propensity Score Analysis

Objective: The goal of the current study was to assess the associations of typical chest imaging findings of bronchopulmonary dysplasia (BPD) in preterm infants with clinical characteristics and outcomes until 2 years of age. Method: This retrospective cohort study enrolled 256 preterm infants with BPD who were admitted between 2014 and 2018. A propensity score analysis was used to adjust for confounding factors. The primary outcomes were the severity of BPD, home oxygen therapy (HOT) at discharge and mortality between 28 days after birth and 2 years of age. A multivariate logistic regression analysis was performed to identify related variables of mortality. Results: Seventy-eight patients with typical chest imaging findings were enrolled, of which 50 (64.1%) were first found by CXR, while 28 (35.9%) were first found by CT. In addition, 85.9% (67/78) were discovered before 36 weeks postmenstrual age (PMA) (gestational age [GA] < 32 weeks) or before 56 days after birth (GA > 32 weeks). After propensity score matching, the matched groups consisted of 58 pairs of patients. Those with typical imaging findings had a remarkably higher mortality rate (29.3 vs. 12.1%, p = 0.022, OR 3.021), higher proportion of severe BPD (32.8 vs. 12.1%, p = 0.003, OR 4.669) and higher rate of HOT at discharge (74.1 vs. 46.6%, p = 0.002, OR 3.291) than those without typical imaging findings. The multivariate logistic regression analysis showed that typical imaging findings ≤ 7 days and typical typical imaging findings >7 days were independent risk factors for mortality in preterm infants with BPD (OR 7.794, p = 0.004; OR 4.533, p = 0.001). Conclusions: More attention should be given to chest imaging findings of BPD, especially in the early stage (within 7 days). Early recognition of the development of BPD helps early individualized treatment of BPD. Clinical Trial Registration:www.ClinicalTrials.gov, identifier: NCT04163822.

Assessment of Postnatal Corticosteroids for the Prevention of Bronchopulmonary Dysplasia in Preterm Neonates: A Systematic Review and Network Meta-analysis

IMPORTANCE

The safety of postnatal corticosteroids used for prevention of bronchopulmonary dysplasia (BPD) in preterm neonates is a controversial matter, and a risk-benefit balance needs to be struck.

OBJECTIVE

To evaluate 14 corticosteroid regimens used to prevent BPD: moderately early-initiated, low cumulative dose of systemic dexamethasone (MoLdDX); moderately early-initiated, medium cumulative dose of systemic dexamethasone (MoMdDX); moderately early-initiated, high cumulative dose of systemic dexamethasone (MoHdDX); late-initiated, low cumulative dose of systemic dexamethasone (LaLdDX); late-initiated, medium cumulative dose of systemic dexamethasone (LaMdDX); late-initiated, high cumulative dose of systemic dexamethasone (LaHdDX); early-initiated systemic hydrocortisone (EHC); late-initiated systemic hydrocortisone (LHC); early-initiated inhaled budesonide (EIBUD); early-initiated inhaled beclomethasone (EIBEC); early-initiated inhaled fluticasone (EIFLUT); late-initiated inhaled budesonide (LIBUD); late-initiated inhaled beclomethasone (LIBEC); and intratracheal budesonide (ITBUD).

DATA SOURCES

PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), Embase, World Health Organization's International Clinical Trials Registry Platform (ICTRP), and CINAHL were searched from inception through August 25, 2020.

STUDY SELECTION

In this systematic review and network meta-analysis, the randomized clinical trials selected included preterm neonates with a gestational age of 32 weeks or younger and for whom a corticosteroid regimen was initiated within 4 weeks of postnatal age. Peer-reviewed articles and abstracts in all languages were included.

DATA EXTRACTION AND SYNTHESIS

Two independent authors extracted data in duplicate. Network meta-analysis used a bayesian model.

MAIN OUTCOMES AND MEASURES

Primary combined outcome was BPD, defined as oxygen requirement at 36 weeks' postmenstrual age (PMA), or mortality at 36 weeks' PMA. The secondary outcomes included 15 safety outcomes.

RESULTS

A total of 62 studies involving 5559 neonates (mean [SD] gestational age, 26 [1] weeks) were included. Several regimens were associated with a decreased risk of BPD or mortality, including EHC (risk ratio [RR], 0.82; 95% credible interval [CrI], 0.68-0.97); EIFLUT (RR, 0.75; 95% CrI, 0.55-0.98); LaHdDX (RR, 0.70; 95% CrI, 0.54-0.87); MoHdDX (RR, 0.64; 95% CrI, 0.48-0.82); ITBUD (RR, 0.73; 95% CrI, 0.57-0.91); and MoMdDX (RR, 0.61; 95% CrI, 0.45-0.79). Surface under the cumulative ranking curve (SUCRA) value ranking showed that MoMdDX (SUCRA, 0.91), MoHdDX (SUCRA, 0.86), and LaHdDX (SUCRA, 0.76) were the 3 most beneficial interventions. ITBUD (RR, 4.36; 95% CrI, 1.04-12.90); LaHdDX (RR, 11.91; 95% CrI, 1.64-44.49); LaLdDX (RR, 6.33; 95% CrI, 1.62-18.56); MoHdDX (RR, 4.96; 95% CrI, 1.14-14.75); and MoMdDX (RR, 3.16; 95% CrI, 1.35-6.82) were associated with more successful extubation from invasive mechanical ventilation. EHC was associated with a higher risk of gastrointestinal perforation (RR, 2.77; 95% CrI, 1.09-9.32). MoMdDX showed a higher risk of hypertension (RR, 3.96; 95% CrI, 1.10-30.91). MoHdDX had a higher risk of hypertrophic cardiomyopathy (RR, 5.94; 95% CrI, 1.95-18.11).

CONCLUSIONS AND RELEVANCE

This study suggested that MoMdDX may be the most appropriate postnatal corticosteroid regimen for preventing BPD or mortality at a PMA of 36 weeks, albeit with a risk of hypertension. The quality of evidence was low.

Postnatal Corticosteroids to Prevent or Treat Bronchopulmonary Dysplasia

Bronchopulmonary dysplasia (BPD) remains a major morbidity for infants born preterm. Postnatal corticosteroids might reduce the risk of developing BPD, or reduce its severity when it occurs, because of their powerful anti-inflammatory effects. However, corticosteroids have adverse effects, including on the developing brain. There have been numerous randomized clinical trials of corticosteroids given via various routes, of varying types, and started at different postnatal ages. There is some evidence that inhaled corticosteroids started earlier in the postnatal period may reduce BPD, but increase mortality. Inhaled corticosteroids started after the first week of age have little effect, but data are sparse. Systemic corticosteroids started in the first week after birth reduce BPD but increase cerebral palsy. Systemic corticosteroids started after the first week of age reduce both BPD and mortality, without evidence of long-term neurological harm. However, no studies have been powered to look for important adverse long-term neurological effects. Of the 2 systemic corticosteroids assessed, most effects relate to dexamethasone and not to hydrocortisone, but hydrocortisone in the first week after birth may reduce mortality, and is worthy of further study. There are limited data directly comparing inhaled versus systemic corticosteroids, with no evidence of superiority of one mode over the other. Corticosteroids instilled into the trachea using surfactant as a vehicle to distribute the drug through the lungs offer promise in preventing BPD. For current clinical practice, systemic corticosteroids should be avoided in the first week of life, and thereafter used only in infants at high risk of BPD.

Bronchopulmonary Dysplasia: Then, Now, and Next

Bronchopulmonary dysplasia (BPD) has evolved considerably since its first description over 50 years ago. This review aims to provide a historical framework for conceptualizing BPD and a current understanding of the changing definition, epidemiology, pathophysiology, treatment, and outcomes of BPD. The transdisciplinary approach that led to the initial phenotypic description of BPD continues to hold promise today. Investigators are refining the definition of BPD in light of changes in clinical care and increasing survival rates of very preterm infants. Despite improvements in perinatal care the incidence of BPD continues to increase. There is growing recognition that antenatal risk factors play a key role in the development of BPD. Strategies designed to prevent or limit neonatal lung injury continue to evolve. Defining the phenotype of infants with BPD can meaningfully direct treatment. Infants with BPD benefit from an interdisciplinary approach to longitudinal care with a focus on growth and neurocognitive development. While the ultimate impact of BPD on long-term pulmonary morbidity remains an active area of investigation, current data indicate that most children and adolescents with a history of BPD have a quality of life comparable to that of other preterm infants.

Postnatal corticosteroids to prevent or treat bronchopulmonary dysplasia in preterm infants

Historically, postnatal corticosteroids have been used to prevent and treat bronchopulmonary dysplasia (BPD), a significant cause of morbidity and mortality in preterm infants. Administering dexamethasone to prevent BPD in the first 7 days post-birth has been associated with increasing risk for cerebral palsy, while early inhaled corticosteroids appear to be associated with an increased risk of mortality. Neither medication is presently recommended to prevent BPD. New evidence suggests that prophylactic hydrocortisone, when initiated in the first 48 hours post-birth, at a physiological dose, and in the absence of indomethacin, improves survival without BPD, with no adverse neurodevelopmental effects at 2 years. This therapy may be considered by clinicians for infants at highest risk for BPD. Routine dexamethasone therapy for all ventilator-dependent infants is not recommended, but after the first week post-birth, clinicians may consider a short course of low-dose dexamethasone (0.15 mg/kg/day to 0.2 mg/kg/day) for individual infants at high risk for, or with evolving, BPD. There is no evidence that hydrocortisone is an effective or safe alternative to dexamethasone for treating evolving or established BPD. Current evidence does not support inhaled corticosteroids for the treatment of BPD.

Allogeneic human umbilical cord-derived mesenchymal stem cells for severe bronchopulmonary dysplasia in children: study protocol for a randomized controlled trial (MSC-BPD trial)

BACKGROUND

Bronchopulmonary dysplasia (BPD) is a complex lung pathological lesion secondary to multiple factors and one of the most common chronic lung diseases. It has a poor prognosis, especially in preterm infants. However, effective therapies for this disease are lacking. Stem-cell therapy is a promising way to improve lung injury and abnormal alveolarization, and the human umbilical cord (hUC) is a good source of mesenchymal stem cells (MSCs), which have demonstrated efficacy in other diseases. We hypothesized that intravenously administered allogeneic hUC-MSCs are safe and effective for severe BPD.

METHODS

The MSC-BPD trial is a randomized, single-center, open-label, dose-escalation, phase-II trial designed to investigate the safety and efficacy of hUC-MSCs in children with severe BPD. In this study, 72 patients will be enrolled and randomly divided into two intervention groups and one control group. Patients in the intervention groups will receive a low dose of hUC-MSCs (n = 24; 2.5 million cells/kg) or a high dose of hUC-MSCs (n = 24; 5 million cells/kg) in combination with traditional supportive treatments for BPD. The patients in the control group (n = 24) will be treated with traditional supportive treatments alone without hUC-MSCs. The primary outcome measures will be cumulative duration of oxygen therapy. Follow-up assessments will be performed at 1, 3, 6, 12, and 24 months post intervention, and the key outcome during follow-up will be changes on chest radiography. Statistical analyses will evaluate the efficacy of the hUC-MSC treatment.

DISCUSSION

This will be the first randomized controlled trial to evaluate the safety and efficacy of intravenously administered hUC-MSCs in children with severe BPD. Its results should provide a new evidence-based therapy for severe BPD.

TRIAL REGISTRATION

ClinicalTrials.gov, ID: NCT03601416. Registered on 26 July 2018.

Recent advances in our understanding of the mechanisms of lung alveolarization and bronchopulmonary dysplasia

Bronchopulmonary dysplasia (BPD) is the most common cause of morbidity and mortality in preterm infants. A key histopathological feature of BPD is stunted late lung development, where the process of alveolarization-the generation of alveolar gas exchange units-is impeded, through mechanisms that remain largely unclear. As such, there is interest in the clarification both of the pathomechanisms at play in affected lungs, and the mechanisms of de novo alveoli generation in healthy, developing lungs. A better understanding of normal and pathological alveolarization might reveal opportunities for improved medical management of affected infants. Furthermore, disturbances to the alveolar architecture are a key histopathological feature of several adult chronic lung diseases, including emphysema and fibrosis, and it is envisaged that knowledge about the mechanisms of alveologenesis might facilitate regeneration of healthy lung parenchyma in affected patients. To this end, recent efforts have interrogated clinical data, developed new-and refined existing-in vivo and in vitro models of BPD, have applied new microscopic and radiographic approaches, and have developed advanced cell-culture approaches, including organoid generation. Advances have also been made in the development of other methodologies, including single-cell analysis, metabolomics, lipidomics, and proteomics, as well as the generation and use of complex mouse genetics tools. The objective of this review is to present advances made in our understanding of the mechanisms of lung alveolarization and BPD over the period 1 January 2017-30 June 2019, a period that spans the 50th anniversary of the original clinical description of BPD in preterm infants.

Development of an ex vivo respiratory pediatric model of bronchopulmonary dysplasia for aerosol deposition studies

Ethical restrictions are limitations of in vivo inhalation studies, on humans and animal models. Thus, in vitro or ex vivo anatomical models offer an interesting alternative if limitations are clearly identified and if extrapolation to human is made with caution. This work aimed to develop an ex vivo infant-like respiratory model of bronchopulmonary dysplasia easy to use, reliable and relevant compared to in vivo infant data. This model is composed of a 3D-printed head connected to a sealed enclosure containing a leporine thorax. Physiological data and pleural-mimicking depressions were measured for chosen respiratory rates. Homogeneity of ventilation was assessed by 81mkrypton scintigraphies. Regional radioaerosol deposition was quantified with 99mtechnetium-diethylene triamine pentaacetic acid after jet nebulization. Tidal volumes values are ranged from 33.16 ± 7.37 to 37.44 ± 7.43 mL and compliance values from 1.78 ± 0.65 to 1.85 ± 0.99 mL/cmH2O. Ventilation scintigraphies showed a homogenous ventilation with asymmetric repartition: 56.94% ± 9.4% in right lung and 42.83% ± 9.36 in left lung. Regional aerosol deposition in lungs exerted 2.60% ± 2.24% of initial load of radioactivity. To conclude the anatomical model satisfactorily mimic a 3-months old BPD-suffering bronchopulmonary dysplasia and can be an interesting tool for aerosol regional deposition studies.

Evaluating the use of corticosteroids in preventing and treating bronchopulmonary dysplasia in preterm neonates

Approximately 15 million babies worldwide are born premature, and complications of prematurity are one of the leading causes of death in neonates. Neonatal respiratory distress syndrome (NRDS) and bronchopulmonary dysplasia (BPD) are two of the most common and serious consequences of prematurity. Synthetic corticosteroids, including dexamethasone, have been central in efforts to treat and prevent BPD. There is strong evidence to show that prenatal corticosteroids reduce infant mortality and the incidence of NRDS, leading to their widespread use in obstetric units. However, data suggest that they are not as effective in reducing the incidence of BPD as NRDS, which may be due to the multifactorial pathogenesis of BPD. On the other hand, the use of postnatal corticosteroids in preterm infants is much more controversial. They have been shown to improve lung function and help in reducing the need for mechanical ventilation. These benefits, however, are associated with a range of adverse short- and long-term effects. This review will discuss the benefits and consequences of corticosteroids in treating BPD and will examine alternative treatments and future research that may improve the understanding of BPD and inform clinical practice.