Randomized Trial of 42-Day Compared with 9-Day Courses of Dexamethasone for the Treatment of Evolving Bronchopulmonary Dysplasia in Extremely Preterm Infants

The use of two or more courses of low-dose systemic dexamethasone to extubate ventilator-dependent preterm neonates may be associated with a higher prevalence of cerebral palsy at two years of corrected age

BACKGROUND

Our objective was to determine whether the use of two or more courses of low-dose systemic dexamethasone for extubation of ventilator-dependent preterm infants after the first week of life, as proposed in the DART study, is associated with greater neurodevelopmental harm at two years of corrected age, compared to a single course.

METHODS

Retrospective review at seven level III neonatal intensive care units. Preterm infants who underwent only one course of systemic dexamethasone for extubation were grouped into DART-1; those who underwent two or more courses were grouped into DART-2. Data and outcomes of infants in DART-2 were compared with those in DART-1.

RESULTS

150 preterm infants were studied: 104 in DART-1 and 46 in DART-2. Patients in DART-2 had a lower gestational age (25 vs. 26 weeks, p = 0.031) and greater morbidity. The average dexamethasone cumulative dose for patients in DART-1 was 0.819 mg/kg, vs. 1.697 mg/kg for patients in DART-2. A total of 14 patients died. The neuromotor and neurosensory assessments at two years of corrected age revealed in the DART-2 survivors, after the multivariate analysis, a higher prevalence of cerebral palsy with functional motor class 2 (OR = 6.837; 95%CI: 1.054-44.337; p = 0.044) and ophthalmological problems requiring the use of glasses (OR = 4.157; 95%CI: 1.026-16.837; p = 0.046).

CONCLUSIONS

In this cohort, the use of more than one course of systemic dexamethasone in low doses for extubation of ventilator-dependent premature infants after the first week of life was associated, at two years of corrected age, with a higher prevalence of cerebral palsy with functional motor class 2 and ophthalmological problems requiring the use of glasses.

A Dose-Limited Dexamethasone and Bubble Continuous Positive Airway Pressure in Ventilation-Dependent Extremely Premature Infants

OBJECTIVE

Dexamethasone has been associated with early extubation and shorter duration of mechanical ventilation in preterm infants. High doses or prolonged courses of dexamethasone may be associated with poor neurodevelopmental outcomes.

STUDY DESIGN

This is an observational cohort study assessing the efficacy of a low-dose short dexamethasone course combined with postextubation bubble continuous positive airway pressure (bCPAP) strategy on rates of successful extubation and reduction of the duration of invasive mechanical ventilation in extremely preterm infants. We compared the short-term outcomes of implementing such strategy on a group of infants with birth weight <750 g to a historical cohort.

RESULTS

Among infants intubated for at least 10 days, median time to extubation from starting the dexamethasone course was 2 days (interquartile range: 1-3). Total duration of intubation was significantly shorter in infants who received dexamethasone compared with the control groups (21 ± 6 vs. 30 ± 10 days, p = 0.03), and although statistically nonsignificant, duration to wean to 21% bCPAP was shorter compared with the control group (48 ± 13 vs. 74 ± 29 days, p = 0.06).

CONCLUSION

A low-dose short dexamethasone course combined with postextubation bCPAP intervention may be associated with successful early extubation and shorter duration of mechanical ventilation.

KEY POINTS

· Noninvasive strategies may not succeed in infants < 750 g birth weight.. · Bubble CPAP has been shown to be associated with reduced complications including chronic lung disease.. · Postnatal dexamethasone therapy may succeed in conjunction with bubble CPAP to reduce reintubation..

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.

Outcomes of postnatal systemic corticosteroids administration in ventilated preterm newborns: a systematic review of randomized controlled trials

Introduction

Prolonged mechanical ventilation, commonly used to assist preterm newborns, increases the risk of developing bronchopulmonary dysplasia (BPD). In recent decades, studies have demonstrated that systemic corticosteroids play a significant role in the prevention and management of BPD. In this systematic review of randomized controlled trials (RCTs), we evaluated the association between the administration of systemic corticosteroids in preterm infants and its long-term outcomes, such as neurodevelopment, growth, extubation rate, and related adverse effects.

Methods

We conducted an electronic search in Medline, Scopus, and PubMed using the following terms: "premature infants" and "corticosteroids." We considered all RCTs published up to June 2023 as eligible. We included all studies involving preterm newborns treated with systemic corticosteroids and excluded studies on inhaled corticosteroids.

Results

A total of 39 RCTs were evaluated. The influence of steroids administered systemically during the neonatal period on long-term neurological outcomes remains unknown, with no influence observed for long-term growth. The postnatal administration of systemic corticosteroids has been found to reduce the timing of extubation and improve respiratory outcomes. Dexamethasone appears to be more effective than hydrocortisone, despite causing a higher rate of systemic hypertension and hyperglycemia. However, in the majority of RCTs analyzed, there were no differences in the adverse effects related to postnatal corticosteroid administration.

Conclusion

Dexamethasone administered during the neonatal period appears to be more effective than hydrocortisone in terms of respiratory outcomes; however, caution should be taken when administering dexamethasone. Data derived from current evidence, including meta-analyses, are inconclusive on the long-term effects of the administration of systemic steroids in preterm infants or the possibility of neurodevelopmental consequences.

Race and Ethnicity of Infants Enrolled in Neonatal Clinical Trials: A Systematic Review

Importance

Representativeness of populations within neonatal clinical trials is crucial to moving the field forward. Although racial and ethnic disparities in research inclusion are well documented in other fields, they are poorly described within neonatology.

Objective

To describe the race and ethnicity of infants included in a sample of recent US neonatal clinical trials and the variability in this reporting.

Evidence Review

A systematic search of US neonatal clinical trials entered into Cochrane CENTRAL 2017 to 2021 was conducted. Two individuals performed inclusion determination, data extraction, and quality assessment independently with discrepancies adjudicated by consensus.

Findings

Of 120 studies with 14 479 participants that met the inclusion criteria, 75 (62.5%) included any participant race or ethnicity data. In the studies that reported race and ethnicity, the median (IQR) percentage of participants of each background were 0% (0%-1%) Asian, 26% (9%-42%) Black, 3% (0%-12%) Hispanic, 0% (0%-0%) Indigenous (eg, Alaska Native, American Indian, and Native Hawaiian), 0% (0%-0%) multiple races, 57% (30%-68%) White, and 7% (1%-21%) other race or ethnicity. Asian, Black, Hispanic, and Indigenous participants were underrepresented, while White participants were overrepresented compared with a reference sample of the US clinical neonatal intensive care unit (NICU) population from the Vermont Oxford Network. Many participants were labeled as other race or ethnicity without adequate description. There was substantial variability in terms and methods of reporting race and ethnicity data. Geographic representation was heavily skewed toward the Northeast, with nearly one-quarter of states unrepresented.

Conclusions and Relevance

These findings suggest that neonatal research may perpetuate inequities by underrepresenting Asian, Black, Hispanic, and Indigenous neonates in clinical trials. Studies varied in documentation of race and ethnicity, and there was regional variation in the sites included. Based on these findings, funders and clinical trialists are advised to consider a 3-point targeted approach to address these issues: prioritize identifying ways to increase diversity in neonatal clinical trial participation, agree on a standardized method to report race and ethnicity among neonatal clinical trial participants, and prioritize the inclusion of participants from all regions of the US in neonatal clinical trials.

Comparing low-dose (DART) and enhanced low-dose dexamethasone regimens in preterm infants with bronchopulmonary dysplasia

Introduction

Determining the optimal dexamethasone dosage for facilitating extubation in extremely low birth weight (ELBW) infants with bronchopulmonary dysplasia (BPD) remains uncertain. This study aims to compare the effectiveness of low-dose (DART) and enhanced low-dose dexamethasone regimens in achieving successful extubation in these infants.

Methods

We conducted a retrospective cohort study at the Women's Wellness and Research Center (WWRC) involving ELBW infants who received dexamethasone for BPD prevention or treatment, or for extubation between January 1st, 2015, and December 31st, 2019. Our goal was to assess successful extubation within various time points of treatement.

Results

A total of 77 patients, matched in gestational age and BW, were enrolled in the study, receiving a total of 121 dexamethasone courses. Low-dose dexamethasone courses were administered 75 times to 49 infants, while 46 courses of enhanced low-dose were given to 28 infants. Treatment commenced at 30.8 ± 3.4 weeks post-menstrual age, compared to 32.1 ± 2.5 weeks in the enhanced low-dose group (p = 0.014). The median (IQR) course duration was seven (3-10) days in the low-dose group, while it was 10 (8-14) days in the enhanced low-dose group (p < 0.001). The median (IQR) course dose was 0.73 (0.53-0.86) mg/kg in the low-dose group and 1.27 (0.97-2.05) mg/kg in the enhanced low-dose group (p < 0.001). There were no differences in extubation success at any time point between the two groups at 72 h and seven days after treatment initiation, by course completion, and within seven days after treatment completion. However, regression analysis identified several predictors of successful extubation; baseline FiO2, course duration, and duration of invasive mechanical ventilation were negatively associated with successful extubation at various time points, while received dose per kg and cumulative dose positively correlated with successful extubation at different time points. No significant differences were observed in secondary outcomes, including death or BPD.

Conclusion

The choice between low-dose and enhanced low-dose dexamethasone regimens may not significantly impact extubation success. However, careful consideration of dosing, ventilation status, and treatment duration remains crucial in achieving successful extubation. This study highlights the need for personalized dexamethasone therapy in ELBW infants.

Systemic corticosteroids for the prevention of bronchopulmonary dysplasia, a network meta-analysis

BACKGROUND

Despite considerable improvement in outcomes for preterm infants, rates of bronchopulmonary dysplasia (BPD) remain high, affecting an estimated 33% of very low birthweight infants, with corresponding long-term respiratory and neurosensory issues. Systemic corticosteroids can address the inflammation underlying BPD, but the optimal regimen for prevention of this disease, balancing of the benefits with the potentially meaningful risks of systemic corticosteroids, continues to be a medical quandary. Numerous studies have shown that systemic corticosteroids, particularly dexamethasone and hydrocortisone, effectively treat or prevent BPD. However, concerning short and long-term side effects have been reported and the optimal approach to corticosteroid treatment remains unclear.

OBJECTIVES

To determine whether differences in efficacy and safety exist between high-dose dexamethasone, moderate-dose dexamethasone, low-dose dexamethasone, hydrocortisone, and placebo in the prevention of BPD, death, the composite outcome of death or BPD, and other relevant morbidities, in preterm infants through a network meta-analysis, generating both pairwise comparisons between all treatments and rankings of the treatments.

SEARCH METHODS

We searched the Cochrane Library for all systematic reviews of systemic corticosteroids for the prevention of BPD and searched for completed and ongoing studies in the following databases in January 2023: Cochrane Central Register of Controlled Trials, MEDLINE, Embase, and clinical trial databases.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) in preterm infants (< 37 weeks' gestation) at risk for BPD that evaluated systemic corticosteroids (high-dose [≥ 4 mg/kg cumulative dose] dexamethasone, moderate-dose [≥ 2 to < 4 mg/kg] dexamethasone, low-dose [< 2 mg/kg] dexamethasone, or hydrocortisone) versus control or another systemic corticosteroid.

DATA COLLECTION AND ANALYSIS

Our main information sources were the systematic reviews, with reference to the original manuscript only for data not included in these reviews. Teams of two paired review authors independently performed data extraction, with disagreements resolved by discussion. Data were entered into Review Manager 5 and exported to R software for network meta-analysis (NMA). NMA was performed using a frequentist model with random-effects. Two separate networks were constructed, one for early (< seven days) initiation of treatment and one for late (≥ seven days) treatment initiation, to reflect the different patient populations evaluated. We assessed the certainty of evidence derived from the NMA for our primary outcomes using principles of the GRADE framework modified for application to NMA.

MAIN RESULTS

We included 59 studies, involving 6441 infants, in our analyses. Only six of the included studies provided direct comparisons between any of the treatment (dexamethasone or hydrocortisone) groups, forcing network comparisons between treatments to rely heavily on indirect evidence through comparisons with placebo/no treatment groups. Thirty-one studies evaluated early corticosteroid treatment, 27 evaluated late corticosteroid treatment, and one study evaluated both early and late corticosteroid treatments. Early treatment (prior to seven days after birth): Benefits:NMA for early treatment showed only moderate-dose dexamethasone to decrease the risk of BPD at 36 weeks' postmenstrual age (PMA) compared with control (RR 0.56, 95% CI 0.39 to 0.80; moderate-certainty evidence), although the other dexamethasone dosing regimens may have similar effects compared with control (high-dose dexamethasone, RR 0.71, 95% CI 0.50 to 1.01; low-certainty evidence; low-dose dexamethasone, RR 0.83, 95% CI 0.67 to 1.03; low-certainty evidence). Other early treatment regimens may have little or no effect on the risk of death at 36 weeks' PMA. Only moderate-dose dexamethasone decreased the composite outcome of death or BPD at 36 weeks' PMA compared with control (RR 0.77, 95% CI 0.60 to 0.98; moderate-certainty evidence).

HARMS

Low-dose dexamethasone increased the risk for cerebral palsy (RR 1.92, 95% CI 1.12 to 3.28; moderate-certainty evidence) compared with control. Hydrocortisone may decrease the risk of major neurosensory disability versus low-dose dexamethasone (RR 0.65, 95% CI 0.41 to 1.01; low-certainty evidence). Late treatment (at seven days or later after birth): Benefits: NMA for late treatment showed high-dose dexamethasone to decrease the risk of BPD both versus hydrocortisone (RR 0.66, 95% CI 0.51 to 0.85; low-certainty evidence) and versus control (RR 0.72, CI 0.59 to 0.87; moderate-certainty evidence). The late treatment regimens evaluated may have little or no effect on the risk of death at 36 weeks' PMA. High-dose dexamethasone decreased risk for the composite outcome of death or BPD compared with all other treatments (control, RR 0.69, 95% CI 0.59 to 0.80, high-certainty evidence; hydrocortisone, RR 0.69, 95% CI 0.58 to 0.84, low-certainty evidence; low-dose dexamethasone, RR 0.73, 95% CI 0.60 to 0.88, low-certainty evidence; moderate-dose dexamethasone, RR 0.76, 95% CI 0.62 to 0.93, low-certainty evidence).

HARMS

No effect was observed for the outcomes of major neurosensory disability or cerebral palsy. The evidence for the primary outcomes was of overall low certainty, with notable deductions for imprecision and heterogeneity across the networks.

AUTHORS' CONCLUSIONS

While early treatment with moderate-dose dexamethasone or late treatment with high-dose dexamethasone may lead to the best effects for survival without BPD, the certainty of the evidence is low. There is insufficient evidence to guide this therapy with regard to plausible adverse long-term outcomes. Further RCTs with direct comparisons between systemic corticosteroid treatments are needed to determine the optimal treatment approach, and these studies should be adequately powered to evaluate survival without major neurosensory disability.

Systemic corticosteroid regimens for prevention of bronchopulmonary dysplasia in preterm infants

BACKGROUND

Systematic reviews showed that systemic postnatal corticosteroids reduce the risk of bronchopulmonary dysplasia (BPD) in preterm infants. However, corticosteroids have also been associated with an increased risk of neurodevelopmental impairment. It is unknown whether these beneficial and adverse effects are modulated by differences in corticosteroid treatment regimens related to type of steroid, timing of treatment initiation, duration, pulse versus continuous delivery, and cumulative dose.

OBJECTIVES

To assess the effects of different corticosteroid treatment regimens on mortality, pulmonary morbidity, and neurodevelopmental outcome in very low birth weight infants.

SEARCH METHODS

We conducted searches in September 2022 of MEDLINE, the Cochrane Library, Embase, and two trial registries, without date, language or publication- type limits. Other search methods included checking the reference lists of included studies for randomized controlled trials (RCTs) and quasi-randomized trials.

SELECTION CRITERIA

We included RCTs comparing two or more different treatment regimens of systemic postnatal corticosteroids in preterm infants at risk for BPD, as defined by the original trialists. The following comparisons of intervention were eligible: alternative corticosteroid (e.g. hydrocortisone) versus another corticosteroid (e.g. dexamethasone); lower (experimental arm) versus higher dosage (control arm); later (experimental arm) versus earlier (control arm) initiation of therapy; a pulse-dosage (experimental arm) versus continuous-dosage regimen (control arm); and individually-tailored regimens (experimental arm) based on the pulmonary response versus a standardized (predetermined administered to every infant) regimen (control arm). We excluded placebo-controlled and inhalation corticosteroid studies.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed eligibility and risk of bias of trials, and extracted data on study design, participant characteristics and the relevant outcomes. We asked the original investigators to verify if data extraction was correct and, if possible, to provide any missing data. We assessed the following primary outcome: the composite outcome mortality or BPD at 36 weeks' postmenstrual age (PMA). Secondary outcomes were: the components of the composite outcome; in-hospital morbidities and pulmonary outcomes, and long-term neurodevelopmental sequelae. We analyzed data using Review Manager 5 and used the GRADE approach to assess the certainty of the evidence.

MAIN RESULTS

We included 16 studies in this review; of these, 15 were included in the quantitative synthesis. Two trials investigated multiple regimens, and were therefore included in more than one comparison. Only RCTs investigating dexamethasone were identified. Eight studies enrolling a total of 306 participants investigated the cumulative dosage administered; these trials were categorized according to the cumulative dosage investigated, 'low' being < 2 mg/kg, 'moderate' being between 2 and 4 mg/kg, and 'high' > 4 mg/kg; three studies contrasted a high versus a moderate cumulative dose, and five studies a moderate versus a low cumulative dexamethasone dose. We graded the certainty of the evidence low to very low because of the small number of events, and the risk of selection, attrition and reporting bias. Overall analysis of the studies investigating a higher dose versus a lower dosage regimen showed no differences in the outcomes BPD, the composite outcome death or BPD at 36 weeks' PMA, or abnormal neurodevelopmental outcome in survivors assessed. Although there was no evidence of a subgroup difference for the higher versus lower dosage regimens comparisons (Chi2 = 2.91, df = 1 (P = 0.09), I2 = 65.7%), a larger effect was seen in the subgroup analysis of moderate-dosage regimens versus high-dosage regimens for the outcome cerebral palsy in survivors. In this subgroup analysis, there was an increased risk of cerebral palsy (RR 6.85, 95% CI 1.29 to 36.36; RD 0.23, 95% CI 0.08 to 0.37; P = 0.02; I² = 0%; NNTH 5, 95% CI 2.6 to 12.7; 2 studies, 74 infants). There was evidence of subgroup differences for higher versus lower dosage regimens comparisons for the combined outcomes death or cerebral palsy, and death and abnormal neurodevelopmental outcomes (Chi2 = 4.25, df = 1 (P = 0.04), I2 = 76.5%; and Chi2 = 7.11, df = 1 (P = 0.008), I2 = 85.9%, respectively). In the subgroup analysis comparing a high dosage regimen of dexamethasone versus a moderate cumulative-dosage regimen, there was an increased risk of death or cerebral palsy (RR 3.20, 95% CI 1.35 to 7.58; RD 0.25, 95% CI 0.09 to 0.41; P = 0.002; I² = 0%; NNTH 5, 95% CI 2.4 to 13.6; 2 studies, 84 infants; moderate-certainty evidence), and death or abnormal neurodevelopmental outcome (RR 3.41, 95% CI 1.44 to 8.07; RD 0.28, 95% CI 0.11 to 0.44; P = 0.0009; I² = 0%; NNTH 4, 95% CI 2.2 to 10.4; 2 studies, 84 infants; moderate-certainty evidence). There were no differences in outcomes between a moderate- and a low-dosage regimen. Five studies enrolling 797 infants investigated early initiation of dexamethasone therapy versus a moderately early or delayed initiation, and showed no significant differences in the overall analyses for the primary outcomes. The two RCTs investigating a continuous versus a pulse dexamethasone regimen showed an increased risk of the combined outcome death or BPD when using the pulse therapy. Finally, three trials investigating a standard regimen versus a participant-individualized course of dexamethasone showed no difference in the primary outcome and long-term neurodevelopmental outcomes. We assessed the GRADE certainty of evidence for all comparisons discussed above as moderate to very low, because the validity of all comparisons is hampered by unclear or high risk of bias, small samples of randomized infants, heterogeneity in study population and design, non-protocolized use of 'rescue' corticosteroids and lack of long-term neurodevelopmental data in most studies.

AUTHORS' CONCLUSIONS

The evidence is very uncertain about the effects of different corticosteroid regimens on the outcomes mortality, pulmonary morbidity, and long term neurodevelopmental impairment. Despite the fact that the studies investigating higher versus lower dosage regimens showed that higher-dosage regimens may reduce the incidence of death or neurodevelopmental impairment, we cannot conclude what the optimal type, dosage, or timing of initiation is for the prevention of BPD in preterm infants, based on current level of evidence. Further high quality trials would be needed to establish the optimal systemic postnatal corticosteroid dosage regimen.

The prevention and management strategies for neonatal chronic lung disease

INTRODUCTION

Survival from even very premature birth is improving, but long-term respiratory morbidity following neonatal chronic lung disease (bronchopulmonary dysplasia (BPD)) has not reduced. Affected infants may require supplementary oxygen at home, because they have more hospital admissions particularly due to viral infections and frequent, troublesome respiratory symptoms requiring treatment. Furthermore, adolescents and adults who had BPD have poorer lung function and exercise capacity.

AREAS COVERED

Antenatal and postnatal preventative strategies and management of infants with BPD. A literature review was undertaken using PubMed and Web of Science.

EXPERT OPINION

There are effective preventative strategies which include caffeine, postnatal corticosteroids, vitamin A, and volume guarantee ventilation. Side-effects, however, have appropriately caused clinicians to reduce use of systemically administered corticosteroids to infants only at risk of severe BPD. Promising preventative strategies which need further research are surfactant with budesonide, less invasive surfactant administration (LISA), neurally adjusted ventilatory assist (NAVA) and stem cells. The management of infants with established BPD is under-researched and should include identifying the optimum form of respiratory support on the neonatal unit and at home and which infants will most benefit in the long term from pulmonary vasodilators, diuretics, and bronchodilators.

Postnatal Corticosteroids to Prevent or Treat Chronic Lung Disease Following Preterm Birth

The American Academy of Pediatrics continues to provide guidance on the use of postnatal corticosteroids to manage or prevent chronic lung disease following preterm birth (formerly referred to as bronchopulmonary dysplasia). Since the last revision of such guidance in 2010, several prospective randomized trials have been published. This revision provides a review of those studies as well as updated recommendations, which include the use of systemic low-dose corticosteroid in preterm neonates with or at high risk for chronic lung disease. High-dose dexamethasone (≥0.5 mg/kg per day) is not recommended. New evidence suggests that inhaled corticosteroids may confer benefit if provided with surfactant as a vehicle, but safety data are lacking. Evidence remains insufficient to make any recommendations regarding routine use of postnatal corticosteroids in preterm infants. Neonatologists and other hospital care providers must continue to use their clinical judgment in individual patients, balancing the potential adverse effects of corticosteroid treatment with those of chronic lung disease. The decision to use postnatal corticosteroids for this purpose should be made together with the infant's parents, and the care providers should document their discussions with parents in the patient's medical record.

Let's Talk about Dex: When do the Benefits of Dexamethasone for Prevention of Bronchopulmonary Dysplasia Outweigh the Risks?

Bronchopulmonary dysplasia (BPD) is the most common complication of extreme prematurity and carries increased respiratory morbidity into childhood and adulthood. Systemic administration of dexamethasone during the preterm period has been shown to decrease the incidence of BPD in this population. However, enthusiasm about its use has been tempered by early evidence that suggested potential adverse neurodevelopmental outcomes. More recent studies suggest that the timing, dosing, and duration of therapy may have a significant impact on the safety and efficacy of dexamethasone administration and that side effects and harms may be minimized if its use is appropriately targeted. Focusing on studies published since the 2010s American Academy of Pediatrics (AAP) statement on dexamethasone, this review seeks to examine the evidence from recent clinical trials to present the current state of knowledge regarding the systemic dexamethasone administration to prevent BPD in extremely premature infants and how dose, duration, and timing might impact its safety and efficacy in this vulnerable population.

Current evidence for prenatal and postnatal corticosteroids in preterm infants

Antenatal corticosteroids undoubtedly save many lives and improve the quality of many others. However, the currently accepted dosage schedule has been in place since 1972, and recent studies have suggested that beneficial effects may be seen with less. Most but not all studies of long-term outcome show no adverse effects. The use of antenatal corticosteroids in women with COVID-19 raises important questions regarding potential risks and benefits. However, currently, most authorities recommend continuing according to published guidelines. With regard to postnatal corticosteroids, alternatives to systemic dexamethasone, the somewhat tainted standard of care, show promise in preventing bronchopulmonary dysplasia without adverse effects. Systemic hydrocortisone and inhaled corticosteroids are of note. The mixture of surfactant and corticosteroids deserves particular attention in the coming years.

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.

Early (&lt; 7 days) systemic postnatal corticosteroids for prevention of bronchopulmonary dysplasia in preterm infants

BACKGROUND

Bronchopulmonary dysplasia (BPD) remains a major problem for infants born extremely preterm. Persistent inflammation in the lungs is important in its pathogenesis. Systemic corticosteroids have been used to prevent or treat BPD because of their potent anti-inflammatory effects.

OBJECTIVES

To examine the relative benefits and adverse effects of systemic postnatal corticosteroids commenced within the first six days after birth for preterm infants at risk of developing BPD.

SEARCH METHODS

We ran an updated search of the following databases on 25 September 2020: 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 cluster randomised trials, cross-over trials, or quasi-RCTs.

SELECTION CRITERIA

For this review, we selected RCTs examining systemic (intravenous or oral) postnatal corticosteroid treatment started within the first six days after birth (early) in high-risk preterm infants. We included studies that evaluated the use of dexamethasone, as well as studies that assessed hydrocortisone, even when the latter was used primarily for management of hypotension, rather than for treatment of lung problems. 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, mortality or BPD, failure to extubate, complications during the primary hospitalisation, and long-term health and neurodevelopmental outcomes. 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 the major outcomes considered, except for BPD at 36 weeks for all studies combined, which was downgraded one level to moderate because of evidence of publication bias. We included 32 RCTs (4395 infants). The overall risk of bias of included studies was low; all were RCTs, and most trials used rigorous methods. Early systemic corticosteroids overall have little or no effect on mortality to the latest reported age (risk ratio (RR) 0.95, 95% confidence interval (CI) 0.85 to 1.06; 31 studies, 4373 infants; high-certainty evidence), but hydrocortisone alone reduces mortality (RR 0.80, 95% CI 0.65 to 0.99; 11 studies, 1433 infants; high-certainty evidence). Early systemic corticosteroids overall probably reduce BPD at 36 weeks' postmenstrual age (PMA) (RR 0.80, 95% CI 0.73 to 0.88; 26 studies, 4167 infants; moderate-certainty evidence), as does dexamethasone (RR 0.72, 95% CI 0.63 to 0.82; 17 studies, 2791 infants; high-certainty evidence), but hydrocortisone has little to no effect (RR 0.92, 95% CI 0.81 to 1.06; 9 studies, 1376 infants; high-certainty evidence). Early systemic corticosteroids overall reduce the combined outcome of mortality or BPD at 36 weeks' PMA (RR 0.89, 95% CI 0.84 to 0.94; 26 studies, 4167 infants; high-certainty evidence), as do both dexamethasone (RR 0.88, 95% CI 0.81 to 0.95; 17 studies, 2791 infants; high-certainty evidence) and hydrocortisone (RR 0.90, 95% CI 0.82 to 0.99; 9 studies, 1376 infants; high-certainty evidence). Early systemic corticosteroids overall increase gastrointestinal perforation (RR 1.84, 95% CI 1.36 to 2.49; 16 studies, 3040 infants; high-certainty evidence), as do both dexamethasone (RR 1.73, 95% CI 1.20 to 2.51; 9 studies, 1936 infants; high-certainty evidence) and hydrocortisone (RR 2.05, 95% CI 1.21 to 3.47; 7 studies, 1104 infants; high-certainty evidence). Early systemic corticosteroids overall increase cerebral palsy (RR 1.43, 95% CI 1.07 to 1.92; 13 studies, 1973 infants; high-certainty evidence), as does dexamethasone (RR 1.77, 95% CI 1.21 to 2.58; 7 studies, 921 infants; high-certainty evidence) but not hydrocortisone (RR 1.05, 95% CI 0.66 to 1.66; 6 studies, 1052 infants; high-certainty evidence). Early systemic corticosteroids overall have little to no effect on the combined outcome of mortality or cerebral palsy (RR 1.03, 95% CI 0.91 to 1.16; 13 studies, 1973 infants; high-certainty evidence), nor does hydrocortisone (RR 0.86, 95% CI 0.71 to 1.05; 6 studies, 1052 infants; high-certainty evidence). However, early dexamethasone probably increases the combined outcome of mortality or cerebral palsy (RR 1.18, 95% CI 1.01 to 1.37; 7 studies, 921 infants; high-certainty evidence), In sensitivity analyses by primary intention for treatment with hydrocortisone (lung problems versus hypotension), there was little evidence of differences in effects on major outcomes of mortality, BPD, or combined mortality or BPD, by indication for the drug.

AUTHORS' CONCLUSIONS

Early systemic postnatal corticosteroid treatment (started during the first six days after birth) prevents BPD and the combined outcome of mortality or BPD. However, it increases risks of gastrointestinal perforation, cerebral palsy, and the combined outcome of mortality or cerebral palsy. Most beneficial and harmful effects are related to early treatment with dexamethasone, rather than to early treatment with hydrocortisone, but early hydrocortisone may prevent mortality, whereas early dexamethasone does not. 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 early 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 early corticosteroids, particularly of hydrocortisone, should include longer-term survival free of neurodevelopmental disability as the primary outcome.

Optimized Clustering Algorithm for Comparative Analysis of Different Prenatal Corticosteroid Neurological Deficits in Premature Infants through Magnetic Reasoning Imaging (MRI)

Objective

This study aimed to explore the application of different prenatal corticosteroids in the assessment of neurological deficits and prognosis in premature infants through Magnetic Reasoning Imaging (MRI) under optimized cluster algorithm.

Methods

100 pregnant women with threatened preterm labor were retrospectively analyzed, in which 38 pregnant women with lasting threatened preterm labor (group A) were treated with multiple courses of antenatal corticosteroids (dexamethasone treatment) and 62 cases of pregnant women with threatened preterm labor (group B) were treated with single course of dexamethasone treatment. Craniocerebral MRI images based on optimal clustering algorithm were used to examine neonates. Neonatal hypoxic-ischemic encephalopathy (HIE) rate, serum neuron-specific enolase (NSE) concentration, neonatal behavioral neurological score (NBNA), respiratory distress syndrome (RDS) rate, perinatal mortality, neonatal birth weight, and maternal complications rate of two groups were compared.

Results

Compared with other traditional image segmentation algorithms, this algorithm had the best segmentation effect, the shortest running time (1.43 s), the least number of iterations (5 times), and the highest segmentation accuracy (97.98%). There was no significant difference in the HIE rate, serum NSE concentration, NBNA score, RDS score, and perinatal mortality in group A and group B (P > 0.05). Compared with group B, neonates' body weight in group A was decreased, while the maternal complication rate in group A was increased (P < 0.05).

Conclusion

MRI images based on optimized clustering algorithm can be used in the diagnosis of neonatal hypoxic-ischemic encephalopathy. There is no significant difference in the application of different antenatal corticosteroids affecting premature nerve function defect and prognosis, but multiple courses of antenatal corticosteroids can affect neonatal body mass and increased maternal complications to a certain extent; therefore, before threatened premature delivery treatment, the pros and cons of multiple courses of antenatal corticosteroids should fully be considered and in the treatment, measures should be actively taken to alleviate the side effect.

Eligibility Criteria and Representativeness of Randomized Clinical Trials That Include Infants Born Extremely Premature: A Systematic Review

OBJECTIVE

To assess the eligibility criteria and trial characteristics among contemporary (2010-2019) randomized clinical trials (RCTs) that included infants born extremely preterm (<28 weeks of gestation) and to evaluate whether eligibility criteria result in underrepresentation of high-risk subgroups (eg, infants born at <24 weeks of gestation).

STUDY DESIGN

PubMed and Scopus were searched January 1, 2010, to December 31, 2019, with no language restrictions. RCTs with mean or median gestational ages at birth of <28 weeks of gestation were included. The study followed the PRISMA guidelines; outcomes were registered prospectively. Data extraction was performed independently by multiple observers. Study quality was evaluated using a modified Jadad scale.

RESULTS

Among RCTs (n = 201), 32 552 infants were included. Study participant characteristics, interventions, and outcomes were highly variable. A total of 1603 eligibility criteria were identified; rationales were provided for 18.8% (n = 301) of criteria. Fifty-five RCTs (27.4%) included infants <24 weeks of gestation; 454 (1.4%) infants were identified as <24 weeks of gestation.

CONCLUSIONS

The present study identifies sources of variability across RCTs that included infants born extremely preterm and reinforces the critical need for consistent and transparent policies governing eligibility criteria.

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.

Tissue-Resident Type 2 Innate Lymphoid Cells Arrest Alveolarization in Bronchopulmonary Dysplasia

Bronchopulmonary dysplasia (BPD) is a severe complication of the respiratory system associated with preterm birth. Type 2 innate lymphoid cells (ILC2s) play a major role in tissue homeostasis, inflammation, and wound healing. However, the role in BPD remains unclear. The present study showed that ILC2s, interleukin-4 (IL-4), IL-13, and anti-inflammatory (M2) macrophages increased significantly in BPD mice as compared to the control mice. Administration with recombinant mouse IL-33 amplified the above phenomena and aggravated the alveolar structural disorder and functional injury in mice subjected to BPD, and the opposite was true with anti-ST2 antibody. In addition, the depletion of ILC2s in BPD mice with anti-CD90.2 antibody substantially abolished the destructive effect on BPD. In the treatment of BPD with dexamethasone, the number of ILC2s and M2 macrophages and levels of IL-4 and IL-13 decreased with remission as compared to the control group. This study identified a major destructive role of the ILC2s in BPD that could be attenuated as a therapeutic strategy.

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.

Systemic corticosteroid regimens for prevention of bronchopulmonary dysplasia in preterm infants

BACKGROUND

Cochrane systematic reviews show that systemic postnatal corticosteroids reduce the risk of bronchopulmonary dysplasia (BPD) in preterm infants. However, corticosteroids have also been associated with an increased risk of neurodevelopmental impairment. It is unknown whether these beneficial and adverse effects are modulated by differences in corticosteroid treatment regimens.

OBJECTIVES

To assess the effects of different corticosteroid treatment regimens on mortality, pulmonary morbidity, and neurodevelopmental outcome in very low birth weight (VLBW) infants.

SEARCH METHODS

We used the standard search strategy of the Cochrane Neonatal Review group to search the Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 2) in the Cochrane Library (searched 21 March 2016), MEDLINE via PubMed (1966 to 21 March 2016), Embase (1980 to 21 March 2016), and CINAHL (1982 to 21 March 2016). We also searched clinical trials' databases, conference proceedings, and the reference lists of retrieved articles for randomized controlled trials.

SELECTION CRITERIA

Randomized controlled trials (RCTs) comparing two or more different treatment regimens of systemic postnatal corticosteroids in preterm infants at risk for BPD, as defined by the original trialists. Studies investigating one treatment regimen of systemic corticosteroids to a placebo or studies using inhalation corticosteroids were excluded.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed eligibility and quality of trials and extracted data on study design, participant characteristics and the relevant outcomes. We asked the original investigators to verify if data extraction was correct and, if possible, to provide any missing data. The primary outcomes to be assessed were: mortality at 36 weeks' postmenstrual age (PMA) or at hospital discharge; BPD defined as oxygen dependency at 36 weeks' PMA; long-term neurodevelopmental sequelae, including cerebral palsy, measured by the Bayley Mental Developmental Index (MDI); and blindness or poor vision. Secondary outcomes were: duration of mechanical ventilation and failure to extubate at day 3 and 7 after initiating therapy; rescue treatment with corticosteroids outside the study period; and the incidence of hypertension, sepsis and hyperglycemia during hospitalizations. Data were analyzed using Review Manager 5 (RevMan 5). We used the GRADE approach to assess the quality of evidence.

MAIN RESULTS

Fourteen studies were included in this review. Only RCTs investigating dexamethasone were identified. Eight studies enrolling a total of 303 participants investigated the cumulative dosage administered; three studies contrasted a high versus a moderate and five studies a moderate versus a low cumulative dexamethasone dose.Analysis of the studies investigating a moderate dexamethasone dose versus a high-dosage regimen showed an increased risk of BPD (typical risk ratio (RR) 1.50, 95% confidence interval (CI) 1.01 to 2.22; typical risk difference (RD) 0.26, 95% CI 0.03 to 0.49; number needed to treat for an additional harmful outcome (NNTH) 4, 95% CI 1.9 to 23.3; I² = 0%, 2 studies, 55 infants) as well as an increased risk of abnormal neurodevelopmental outcome (typical RR 8.33, 95% CI 1.63 to 42.48; RD 0.30, 95% CI 0.14 to 0.46; NNTH 4, 95% CI 2.2 to 7.3; I² = 68%, 2 studies, 74 infants) when using a moderate cumulative-dosage regimen. The composite outcomes of death or BPD and death or abnormal neurodevelopmental outcome showed similar results although the former only reached borderline significance.There were no differences in outcomes between a moderate- and a low-dosage regimen.Four other studies enrolling 762 infants investigated early initiation of dexamethasone therapy versus a moderately early or delayed initiation and showed no significant differences in the primary outcomes. The two RCTs investigating a continuous versus a pulse dexamethasone regimen showed an increased risk of the combined outcome death or BPD when using the pulse therapy. Finally, two trials investigating a standard regimen versus a participant-individualized course of dexamethasone showed no difference in the primary outcome and long-term neurodevelopmental outcomes.The quality of evidence for all comparisons discussed above was assessed as low or very low, because the validity of all comparisons is hampered by small samples of randomized infants, heterogeneity in study population and design, non-protocolized use of 'rescue' corticosteroids and lack of long-term neurodevelopmental data in most studies.

AUTHORS' CONCLUSIONS

Despite the fact that some studies reported a modulating effect of treatment regimens in favor of higher-dosage regimens on the incidence of BPD and neurodevelopmental impairment, recommendations on the optimal type of corticosteroid, the optimal dosage, or the optimal timing of initiation for the prevention of BPD in preterm infants cannot be made based on current level of evidence. A well-designed large RCT is urgently needed to establish the optimal systemic postnatal corticosteroid dosage regimen.