Invasive mechanical ventilation at 36 weeks post-menstrual age, adverse outcomes with a comparison of recent definitions of bronchopulmonary dysplasia

Outcomes of infants and children with bronchopulmonary dysplasia-associated pulmonary hypertension who required home ventilation

BACKGROUND

To characterize a cohort of ventilator-dependent infants and children with bronchopulmonary dysplasia-associated pulmonary hypertension (BPD-PH) and to describe their cardiorespiratory outcomes.

METHODS

Subjects with BPD on chronic home ventilation were recruited from outpatient clinics. PH was defined by its presence on ≥1 cardiac catheterization or echocardiogram on or after 36 weeks post-menstrual age. Kaplan-Meier analysis was used to compare the timing of key events.

RESULTS

Of the 154 subjects, 93 (60.4%) had PH and of those, 52 (55.9%) required PH-specific medications. The ages at tracheostomy, transition to home ventilator, and hospital discharge were older in those with PH. Most subjects were weaned off oxygen and liberated from the ventilator by 5 years of age, which did not occur later in subjects with PH. The mortality rate after initial discharge was 2.6%.

CONCLUSIONS

The majority of infants with BPD-PH receiving chronic invasive ventilation at home survived after initial discharge. Subjects with BPD-PH improved over time as evidenced by weaning off oxygen and PH medications, ventilator liberation, and tracheostomy decannulation. While the presence of PH was not associated with later ventilator liberation or decannulation, the use of PH medications may be a marker of a more protracted disease trajectory.

IMPACT STATEMENT

There is limited data on long-term outcomes of children with bronchopulmonary dysplasia (BPD) who receive chronic invasive ventilation at home, and no data on those with the comorbidity of pulmonary hypertension (PH). Almost all subjects with BPD-PH who were on chronic invasive ventilation at home survived after their initial hospital discharge. Subjects with BPD-PH improved over time as evidenced by weaning off oxygen, PH medications, liberation from the ventilator, and tracheostomy decannulation. The presence of PH did not result in later ventilator liberation or decannulation; however, the use of outpatient PH medications was associated with later ventilation liberation and decannulation.

Timeline of Weaning in Pediatric Long-Term Mechanical Ventilator Dependent Children: A Longitudinal Cohort Study

BACKGROUND

Children with invasive long-term mechanical ventilation (LTMV) dependence are a complex, heterogeneous population with wide variability in respiratory outcomes. Limited data exist on their ventilator weaning trajectories and respiratory characteristics as they progress toward liberation from the ventilator.

OBJECTIVE

To describe a population of children with invasive LTMV dependence who have successfully liberated from ventilator support, focusing on ventilator parameters as potential early predictors of liberation.

METHODS

This was a retrospective study of children who initiated chronic ventilator support at < 12 months of age at our institution, received ventilator support through a tracheostomy tube, were followed through our outpatient clinic, and were fully liberated from mechanical ventilation. Our primary outcome was age at liberation from ventilator support. Multiple covariates were described, including baseline descriptors, health system utilization descriptors, disease markers, and care milestones.

RESULTS

Seventy-eight patients were identified. The median age of tracheostomy was 3.8 [IQR: 3.0-4.8] months. The median age of first hospital discharge to home care was 9.3 months [IQR: 7.5-12], with a median of 44 hospital encounters after initial discharge. These patients were liberated at a median age of 23.9 [18.3-32.2] months. Age at liberation from the ventilator was highly variable within our institution.

CONCLUSION

The most significant variation in outcome was introduced after hospital discharge and appears to be largely independent of lung disease severity as indicated by ventilatory support. No single covariate was strongly correlated with liberation outcome. Further studies are needed to identify underlying pathophysiology that may contribute to the varied weaning trajectories to better define objective weaning strategies.

Surfactant treatment at birth in a contemporary cohort of preterm infants with bronchopulmonary dysplasia

OBJECTIVE

Initial surfactant studies demonstrated improvements in survival and need for respiratory support. However, as the use of non-invasive respiratory support has increased the use of surfactant has decreased. We examined in a contemporary cohort of BPD patients if surfactant use was associated with BPD severity.

STUDY DESIGN

An observational study using data from the BPD Collaborative Registry.

RESULTS

971 infants with BPD met entry criteria, 864 (89%) had received surfactant in the first 72 h of life (SURF) and the remainder had not (no surfactant). There was an association between SURF and BPD grade, with a greater likelihood of grade 3 BPD in infants who received surfactant in the DR or who had 2 or more doses.

CONCLUSIONS

We speculate that the use of surfactant in the DR and use of multiple doses reflect the impact of perinatal factors beyond immaturity alone that increase the risk for grade 3 BPD.

Managing established bronchopulmonary dysplasia without using routine blood gas measurements

OBJECTIVE

Routine blood gas measurements are common in infants with severe bronchopulmonary dysplasia (sBPD) and are a noxious stimulus. We developed a guideline-driven approach to evaluate the care of infants with sBPD without routine blood gas sampling in the chronic phase of NICU care (after diagnosis at 36 weeks PMA).

STUDY DESIGN

We examined blood gas utilization and outcomes in our sBPD inpatient care unit using data collected between 2014 and 2020.

RESULTS

485 sBPD infants met inclusion criteria, and 303 (62%) never had a blood gas obtained after 36 weeks PMA. In infants who had blood gas measurements, the median number of total blood gases per patient was only 4 (IQR 1-10). We did not identify adverse effects on hospital outcomes in patients without routine blood gas measurements.

CONCLUSIONS

We found that patients with established BPD could be managed without routine blood gas analyses after 36 weeks PMA.

The impact of early tracheostomy on neurodevelopmental outcomes of infants with severe bronchopulmonary dysplasia exposed to postnatal corticosteroids

OBJECTIVE

To compare the cognitive, language and motor scores of infants with severe BPD exposed to postnatal corticosteroids (PCS) and had early (ET), late (LT) or no tracheostomy (NT).

METHODS

Retrospective study was designed to compare the developmental outcomes of 71 infants born between 2010 and 2017 with severe BPD exposed to PCS and had ET (≤122 days), LT (>122 days), or NT.

RESULTS

Cognitive scores were lower in LT versus NT and ET (p = 0.050); motor scores were worse in LT versus NT and ET (p = 0.004). Dexamethasone use was higher in LT versus NT and ET (p = 0.040). Adjusted for PCS, odds for major cognitive impairment were 90% less in ET versus LT. Trend for improved language and motor outcomes was seen in ET versus LT.

CONCLUSION

Infants with severe BPD exposed to PCS and had ET had significantly better cognitive, and trend toward improved language and motor outcomes.

Association between viral infection and bronchopulmonary dysplasia in preterm infants: a systematic review and meta-analysis

Bronchopulmonary dysplasia (BPD) is the most common serious complication of very preterm infants (VPI) or very low birth weight (VLBW) infants. Studies implicate viral infections in etiopathogenesis. The aim of this study was to summarize the relationship between viral infections and BPD through a systematic review and meta-analysis. We searched PubMed, Embase, the Web of Science Core Collection, and the Cochrane Database on December 19, 2023. We included observational studies that examined the association between viral infections and BPD in preterm infants. We extracted data on study methods, participant characteristics, exposure assessment, and outcome measures. We assessed study risk of bias using the Newcastle-Ottawa Scale (NOS). We included 17 and 15 studies in the qualitative review and meta-analysis, respectively. The meta-analysis showed a significant association between viral infection and BPD diagnosed at 36 weeks postmenstrual age (odds ratio (OR): 2.42, 95% confidence interval: 1.89-3.09, 13 studies, very low certainty of evidence). In a subgroup analysis of specific viruses, cytomegalovirus (CMV) proved to be significantly associated with BPD diagnosed at 36 weeks postmenstrual age (OR: 2.34, 95% confidence interval: 1.80-3.05, 11 studies). We did not find an association between viral infection and BPD diagnosed on the 28th day of life, probably due to the small sample size of the included prospective studies.  Conclusion: Viral infections, especially CMV, are associated with an increased risk of BPD in preterm infants. Methodologically reliable prospective studies with large samples are needed to validate our conclusions, and high-quality randomized controlled studies are needed to explore the effect of prevention or treatment of viral infections on the incidence of BPD. What is Known: • Studies have attempted to identify viral infections and bronchopulmonary dysplasia in preterm infants; however, results have been inconsistent. What is New: • Systematic demonstration that viral infections, particularly cytomegalovirus, are positively associated with bronchopulmonary dysplasia diagnosed in preterm infants at the 36th week of postmenstrual age. • The importance of screening for viral infections in preterm infants, especially cytomegalovirus. More high-quality studies should be produced in the future to investigate the causal relationship between viral infections and bronchopulmonary dysplasia.

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

BACKGROUND

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

RESEARCH QUESTION

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

STUDY DESIGN AND METHODS

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

RESULTS

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

INTERPRETATION

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

A clinical informatics approach to bronchopulmonary dysplasia: current barriers and future possibilities

Bronchopulmonary dysplasia (BPD) is a complex, multifactorial lung disease affecting preterm neonates that can result in long-term pulmonary and non-pulmonary complications. Current therapies mainly focus on symptom management after the development of BPD, indicating a need for innovative approaches to predict and identify neonates who would benefit most from targeted or earlier interventions. Clinical informatics, a subfield of biomedical informatics, is transforming healthcare by integrating computational methods with patient data to improve patient outcomes. The application of clinical informatics to develop and enhance clinical therapies for BPD presents opportunities by leveraging electronic health record data, applying machine learning algorithms, and implementing clinical decision support systems. This review highlights the current barriers and the future potential of clinical informatics in identifying clinically relevant BPD phenotypes and developing clinical decision support tools to improve the management of extremely preterm neonates developing or with established BPD. However, the full potential of clinical informatics in advancing our understanding of BPD with the goal of improving patient outcomes cannot be achieved unless we address current challenges such as data collection, storage, privacy, and inherent data bias.

To Trach or Not To Trach: Long-term Tracheostomy Outcomes in Infants with BPD

See Bonus NeoBriefs videos and downloadable teaching slides Infants born preterm who are diagnosed with bronchopulmonary dysplasia (BPD) demonstrate a wide spectrum of illness severity. For infants with the most severe forms of BPD, safe discharge from the hospital may only be possible by providing long-term ventilation via a surgically placed tracheostomy. Though tracheostomy placement in infants with BPD is infrequent, recent reports suggest that rates of tracheostomy placement are increasing in this population. Even though there are known respiratory and neurodevelopmental risks associated with tracheostomy placement, no evidence-based criteria or consensus clinical practice guidelines exist to inform tracheostomy placement in this growing and vulnerable population. An incomplete knowledge of long-term post-tracheostomy outcomes in infants with BPD may unduly bias medical decision-making and family counseling regarding tracheostomy placement. This review aims to summarize our current knowledge of the epidemiology and long-term outcomes of tracheostomy placement in infants with BPD to provide a family-centered framework for tracheostomy counseling.

Tracheostomy in Severe Bronchopulmonary Dysplasia-How to Decide in the Absence of Evidence

Infants with the most severe forms of bronchopulmonary dysplasia (BPD) may require long-term invasive positive pressure ventilation for survival, therefore necessitating tracheostomy. Although life-saving, tracheostomy has also been associated with high mortality, postoperative complications, high readmission rates, neurodevelopmental impairment, and significant caregiver burden, making it a highly complex and challenging decision. However, for some infants tracheostomy may be necessary for survival and the only way to facilitate a timely and safe transition home. The specific indications for tracheostomy and the timing of the procedure in infants with severe BPD are currently unknown. Hence, centers and clinicians display broad variations in practice with regard to tracheostomy, which presents barriers to designing evidence-generating studies and establishing a consensus approach. As the incidence of severe BPD continues to rise, the question remains, how do we decide on tracheostomy to provide optimal outcomes for these patients?

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Bronchopulmonary Dysplasia: Ongoing Challenges from Definitions to Clinical Care

Bronchopulmonary dysplasia (BPD) is the most common complication of extreme prematurity. Its etiology is multifactorial and is attributed to genetic susceptibility to prenatal and postnatal factors. As advancements in neonatology have led to the increased survival of premature infants, a parallel increase in the incidence of BPD has occurred. Over time, the definition and diagnostic criteria for BPD have evolved, as have management strategies. However, challenges continue to exist in the management of these infants, which is not surprising given the complexity of the disease. We summarize the key diagnostic criteria and provide insight into the challenges related to various aspects of BPD definitions, data comparisons, and clinical care implementation.

Respiratory Outcomes for Ventilator-Dependent Children With Bronchopulmonary Dysplasia

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Outcomes of infants with severe bronchopulmonary dysplasia who received tracheostomy and home ventilation

OBJECTIVE

To describe the survival rate, timing of liberation from the ventilator, and factors favorable for decannulation among infants with severe bronchopulmonary dysplasia (sBPD) who received tracheostomy.

METHODS

Demographics and clinical outcomes were obtained through retrospective chart review of 98 infants with sBPD who were born between 2004 and 2017, received tracheostomy at <1 year of age, and were followed in the Infant Tracheostomy and Home Ventilator clinic up to 4 years of age.

RESULTS

The number of infants with sBPD who received tracheostomy increased significantly over the study period. The median age at tracheostomy was 4 months (IQR 3, 5) or 43 weeks corrected gestational age; the median age at NICU discharge was 7 months (IQR 6, 9). At 48 months of age, all subjects had been liberated from the ventilator, at a median age of 24 months (IQR 18, 29); 52% had been decannulated with a median age at decannulation of 32 months (IQR 26, 39). Only 1 (1%) infant died. Multivariate logistic regression showed infants who were White, liberated from the ventilator by 24 months of age and have public insurance had significantly greater odds of being decannulated by 48 months of age. Tracheobronchomalacia was associated with decreased odds of decannulation.

CONCLUSION

Infants with sBPD who received tracheostomy had an excellent survival rate. Liberation from home ventilation and decannulation are likely to occur by 4 years of age.

Association of newer definitions of bronchopulmonary dysplasia with pulmonary hypertension and long-term outcomes

BACKGROUND

The definition of bronchopulmonary dysplasia (BPD) has been evolved recently from definition by the National Institute of Child Health and Human Development in 2001 (NICHD 2001) to the definition reported in 2018 (NICHD 2018) and that proposed by Jensen et al. in 2019 (NICHD 2019). The definition was developed based on the evolution of non-invasive respiratory support and to achieve better prediction of later outcomes. Our objective was to evaluate the association between different definitions of BPD and occurrence of pulmonary hypertension (PHN) and long term outcomes.

METHODS

This retrospective study enrolled preterm infants born at < 32 weeks of gestation between 2014 and 2018. The association between re-hospitalization owing to a respiratory illness until a corrected age (CA) of 24 months, neurodevelopmental impairment (NDI) at a CA of 18-24 months, and PHN at a postmenstrual age (PMA) of 36 weeks was evaluated, with the severity of BPD defined based on these three definitions.

RESULTS

Among 354 infants, the gestational age and birth weight were the lowest in severe BPD based on the NICHD 2019 definition. In total, 14.1% of the study population experienced NDI and 19.0% were re-hospitalized owing to a respiratory illness. At a PMA of 36 weeks, PHN was identified in 9.2% of infants with any BPD. Multiple logistic regression analysis showed that the adjusted odds ratio (OR) for re-hospitalization was the highest for Grade 3 BPD of the NICHD 2019 criteria (5.72, 95% confidence interval [CI]: 1.37-23.92), while the adjusted OR of Grade 3 BPD was 4.96 (95% CI: 1.73-14.23) in the NICHD 2018 definition. Moreover, no association of the severity of BPD was found in the NICHD 2001 definition. The adjusted ORs for NDI (12.09, 95% CI: 2.52-58.05) and PHN (40.37, 95% CI: 5.15-316.34) were also the highest for Grade 3 of the NICHD 2019 criteria.

CONCLUSION

Based on recently suggested criteria by the NICHD in 2019, BPD severity is associated with long-term outcomes and PHN at a PMA of 36 weeks in preterm infants.

Safety and Efficacy of Mesenchymal Stem Cells for the Treatment of Evolving and Established Bronchopulmonary Dysplasia: A Systematic Literature Review

Bronchopulmonary dysplasia (BPD) is a frequent sequela of modern medicine when infants are born prematurely. Currently, there is no single treatment or combination of treatments to prevent or fully treat BPD. Mesenchymal stem cells (MSCs) have promising properties that could aid in the reversal of lung injury, as seen in patients with BPD. This study reviews the available evidence regarding the safety and efficacy of the use of MSCs for the treatment of evolving and established BPD. This systematic review was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). We found eight studies that fulfilled the inclusion and exclusion criteria. While all studies proved the safety and efficacy of MSCs administered intravenously and intratracheally, the only available randomized controlled trial (RCT) failed to demonstrate the benefit of MSC administration in the early treatment of BPD. The remaining studies varied between phase I clinical trials and case reports, but all seemed to show some evidence that MSCs may be of benefit in the late treatment of established BPD. Considering some of the studies have less evidence, early treatment to prevent lung fibrosis may be more successful, particularly in the younger gestational ages where lung development is more immature, and research should focus on this.

Contributions of the NICHD neonatal research network to the diagnosis, prevention, and treatment of bronchopulmonary dysplasia

Despite improvements in the care and outcomes of infants born extremely preterm, bronchopulmonary dysplasia (BPD) remains a common and frustrating complication of prematurity. This review summarizes the BPD-focused research conducted by the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network (NRN). To improve disease classification and outcome prediction, the NRN developed new data-driven diagnostic criteria for BPD and web-based tools that allow clinicians and investigators to reliably estimate BPD risk in preterm infants. Randomized trials of intramuscular vitamin A and prophylactic nasal continuous positive airway pressure conducted by the NRN have contributed to our current use of these therapies as evidence-based approaches to reduce BPD risk. A recent large, randomized trial of hydrocortisone administered beginning between the 2nd and 4th postnatal weeks provided strong evidence that this therapy promotes successful extubation but does not lower BPD rates. Ongoing studies within the NRN will address important, unanswered questions on the risks and benefits of intratracheal surfactant/corticosteroid combinations and treatment versus expectant management of the patent ductus arteriosus to prevent BPD.

Comparison of definitions of bronchopulmonary dysplasia to reflect the long-term outcomes of extremely preterm infants

Survivors of neonatal bronchopulmonary dysplasia (BPD) have persistent respiratory, neurodevelopmental, and growth impairment over the first few years of life and later childhood, which represents an emerging burden for health systems. Therefore, there is an increasing need for a new definition and grading system of BPD that predicts long-term outcomes of high-risk infants who need timely and proper intervention to improve outcomes. We compared new definitions of BPD (National Institute of Child Health and Human Development [NICHD] 2018 and Neonatal Research Network [NRN] 2019) to the original NICHD 2001 definition at 3 years of age using a nationwide cohort of extreme preterm infants. New definitions and severity grading were clearly related to respiratory, neurodevelopmental, and growth impairments at 3 years of age and at 18-24 months corrected age (CA), whereas the original NICHD 2001 definition was not. Furthermore, the negative effect of BPD on growth was ameliorated at 3 years of age compared to 18-24 months CA. However, the negative effect of BPD in neonates on the respiratory system and neurodevelopment persisted at 3 years of age. These new definitions should be adopted to identify high-risk infants and improve long-term outcomes by exact diagnosis and BPD severity classification.

Association of Racial Disparities With In-Hospital Outcomes in Severe Bronchopulmonary Dysplasia

Importance

Bronchopulmonary dysplasia (BPD) is the most common serious morbidity of preterm birth. Short-term respiratory outcomes for infants with the most severe forms of BPD are highly variable. The mechanisms that explain this variability remain unknown and may be mediated by racial disparities.

Objective

To determine the association of maternal race with death and length of hospital stay in a multicenter cohort of infants with severe BPD.

Design, Setting, and Participants

This multicenter cohort study included preterm infants enrolled in the BPD Collaborative registry from January 1, 2015, to July 19, 2021, involving 8 BPD Collaborative centers located in the US. Included patients were born at less than 32 weeks' gestation, had a diagnosis of severe BPD as defined by the 2001 National Institutes of Health Consensus Criteria, and were born to Black or White mothers.

Exposures

Maternal race: Black vs White.

Main Outcomes and Measures

Death and length of hospital stay.

Results

Among 834 registry infants (median [IQR] gestational age, 25 [24-27] weeks; 492 male infants [59%]) meeting inclusion criteria, the majority were born to White mothers (558 [67%]). Death was observed infrequently in the study cohort (32 [4%]), but Black maternal race was associated with an increased odds of death (adjusted odds ratio, 2.1; 95% CI, 1.2-3.5) after adjusting for center. Black maternal race was also significantly associated with length of hospital stay (adjusted between-group difference, 10 days; 95% CI, 3-17 days).

Conclusions and Relevance

In a multicenter severe BPD cohort, study results suggest that infants born to Black mothers had increased likelihood of death and increased length of hospital stay compared with infants born to White mothers. Prospective studies are needed to define the sociodemographic mechanisms underlying disparate health outcomes for Black infants with severe BPD.

Steroid use for established bronchopulmonary dysplasia: study protocol for a systematic review and meta-analysis

INTRODUCTION

Postnatal steroids during the first few weeks of life have been demonstrated to be effective in decreasing the incidence of bronchopulmonary dysplasia (BPD), a serious chronic respiratory condition affecting preterm infants. However, this preventive option is limited by the concern of neurological side effects. Steroids are used to treat established BPD in an attempt to reduce mortality, and length of stay and home oxygen therapy, both of which associated with high levels of parental stress and healthcare costs. Moreover, a late timing for steroid treatment may show a more favourable safety profile in terms of neurodevelopment outcomes, considering the added postnatal brain maturation of these infants. Here, we report a protocol for a systematic review, which aims to determine the efficacy and long-term safety of postnatal steroids for the treatment of established BPD in preterm infants.

METHODS AND ANALYSIS

MEDLINE, Embase, Cochrane databases and sources of grey literature for conference abstracts and trial registrations will be searched with no time or language restriction. We will include case-control studies, cohort studies and non-randomised or randomised trials that evaluate postnatal steroids for infants diagnosed with moderate or severe established BPD at 36 weeks' postmenstrual age. We will pool data from studies that are sufficiently similar to make this appropriate. Data extraction forms will be developed a priori. Observational studies and non-randomised and randomised clinical trials will be analysed separately. We will combine OR with 95% CI for dichotomous outcomes and the mean difference (95% CI) for continuous outcomes. We will account for the expected heterogeneity by using a random-effects model. We will perform subgroup analysis based on the a priori determined covariate of interest.

ETHICS AND DISSEMINATION

Systematic reviews are exempted from approval by an ethics committee. Attempts will be sought to publish all results.

PROSPERO REGISTRATION NUMBER

CRD42021218881.

Endotypes of Prematurity and Phenotypes of Bronchopulmonary Dysplasia: Toward Personalized Neonatology

Bronchopulmonary dysplasia (BPD), the chronic lung disease of prematurity, is increasingly recognized as the consequence of a pathological reparative response of the developing lung to both antenatal and postnatal injury. According to this view, the pathogenesis of BPD is multifactorial and heterogeneous with different patterns of antenatal stress (endotypes) that combine with varying postnatal insults and might distinctively damage the development of airways, lung parenchyma, interstitium, lymphatic system, and pulmonary vasculature. This results in different clinical phenotypes of BPD. There is no clear consensus on which are the endotypes of prematurity but the combination of clinical information with placental and bacteriological data enables the identification of two main pathways leading to birth before 32 weeks of gestation: (1) infection/inflammation and (2) dysfunctional placentation. Regarding BPD phenotypes, the following have been proposed: parenchymal, peripheral airway, central airway, interstitial, congestive, vascular, and mixed phenotype. In line with the approach of personalized medicine, endotyping prematurity and phenotyping BPD will facilitate the design of more targeted therapeutic and prognostic approaches.

Noninvasive Respiratory Severity Indices Predict Adverse Outcomes in Bronchopulmonary Dysplasia

OBJECTIVE

To test the hypothesis that elevated respiratory severity indices will identify patients with severe bronchopulmonary dysplasia (BPD) at the greatest risk for adverse in-hospital outcomes.

STUDY DESIGN

This was a retrospective cohort study. A modified respiratory severity score (mean airway pressure × fraction of inspired oxygen) and a modified pulmonary score (respiratory support score × fraction of inspired oxygen + sum of medication scores) were calculated in a consecutive cohort of patients ≥36 weeks of postmenstrual age with severe BPD admitted to a referral center between 2010 and 2018. The association between each score and the primary composite outcome of death/prolonged length of stay (>75th percentile for cohort) was assessed using area under the receiver operator characteristic curve (AUROC) analysis and logistic regression. Death and the composite outcome death/tracheostomy were analyzed as secondary outcomes.

RESULTS

In 303 patients, elevated scores were significantly associated with increased adjusted odds of death/prolonged length of stay: aOR 1.5 (95% CI 1.3-1.7) for the modified respiratory severity score and aOR 11.5 (95% CI 5.5-24.1) for the modified pulmonary score. The modified pulmonary score had slightly better discrimination of death/prolonged length of stay when compared with the modified respiratory severity score, AUROC 0.90 (95% CI 0.85-0.94) vs 0.88 (95% CI 0.84-0.93), P = .03. AUROCs for death and death/tracheostomy did not differ significantly when comparing the modified respiratory severity score with the modified pulmonary score.

CONCLUSIONS

In our referral center, the modified respiratory severity score or the modified pulmonary score identified patients with established severe BPD at the greatest risk for death/prolonged length of stay, death, and death/tracheostomy.

Volume-guarantee vs. pressure-limited ventilation in evolving bronchopulmonary dysplasia

INTRODUCTION

Extremely premature infants are at high risk for developing bronchopulmonary dysplasia (BPD). While noninvasive support is preferred, they may require ventilator support. Although volume-targeted ventilation (VTV) has been shown to be beneficial in preventing BPD, no data exists to guide ventilator management of infants with evolving BPD. Thus, clinicians employ a host of ventilator strategies, traditionally time-cycled pressure-limited ventilation (PLV) and more recently volume-guarantee ventilation (VGV) (a form of VTV). In this study, we sought to test the hypothesis that use of VGV in evolving BPD is associated with improved clinical and pulmonary outcomes when compared with PLV.

DESIGN

Single-center, retrospective cohort review of premature infants born less than 28 weeks inborn to a Level 4 NICU from January 2015 to December 2020. Data abstracted included demographics, maternal and birth data, and ventilator data until death or discharge. Exposure to either VGV or PLV was also examined, including ventilator "dose" (number of time points from DOL 14, 21 and 28 the patient was on that particular ventilator) during the period of evolving BPD.

RESULTS

Of a total of 471 patients with ventilation data available on DOL 14, 268 were not ventilated and 203 were ventilated. PLV at DOL 21 and 28 was associated with significantly higher risk of BPD and the composite outcome of BPD or death before 36 weeks compared to VGV. Both increasing VGV and PLV doses were significantly associated with higher odds of BPD and the composite outcome. For each additional time point of VGV and PLV exposure, the predicted length of stay (LOS) increased by 15.3 days (p < 0.001) and 28.8 days (p < 0.001), respectively.

DISCUSSION

Our study demonstrates the association of use of VGV at DOL 21 and 28 with decreased risk of BPD compared to use of PLV. Prospective trials are needed to further delineate the most effective ventilatory modality for this population with "evolving" BPD.

Comparisons of two definitions of bronchopulmonary dysplasia for the premature infants

OBJECTIVE

Bronchopulmonary dysplasia (BPD) is a very common respiratory disease in premature infants, but there is still a different understanding of the definition of BPD. Therefore, this study is intended to compare are main clinical results and health economic expenditures under different BPD definitions.

METHODS

This study included premature infants who came into the neonatal intensive care unit (NICU) from January 2018 to January 2020, who were not more than 32 weeks of premenstrual age. The main clinical consequences and health economic expenditures were analyzed by the National Institute of Health and Human Development definition (Workshop) and Jensen definition.

RESULTS

Total 303 survivors were evaluated at 36 weeks. BPD was performed in 47.5% and 37.6% of infants, respectively, with Workshop's and Jensen's definitions. The percentage of unclassified BPD infants was 0.9% in Workshop's and 3.3% in Jensen's definitions. Further discussing the health economic burden and found that Jensen's definitions had a significantly correlated with NICU charges than the Workshop's definitions.

CONCLUSION

Comparing the Workshop definition of BPD, the Jensens definition was better correlated to health expenditure.