Characterization of Disease Phenotype in Very Preterm Infants with Severe Bronchopulmonary Dysplasia

Current and Emerging Therapies for Prevention and Treatment of Bronchopulmonary Dysplasia in Preterm Infants

Although advances in the care of extremely preterm born infants have yielded improvements in survival and reductions in important morbidities, rates of bronchopulmonary dysplasia (BPD) have remained relatively unchanged. As BPD can have a long-lasting impact on the quality of life for survivors of prematurity and their families, this remains a continuing challenge. Treatments that have consistently shown efficacy in preventing either BPD or the composite outcome of BPD and death prior to 36 weeks post menstrual age (PMA) in large-scale randomized clinical trials (RCTs) include caffeine [adjusted odds ratio aOR for BPD, 0.63; 95% confidence interval (95% CI) 0.52-0.76; p < 0.001)], vitamin A [relative risk (RR) for death or BPD 0.89; 95% CI 0.80-0.99], low-dose hydrocortisone in the first week of life [OR for survival without BPD, 1.45; 95% CI 1.11-1.90; p = 0.007], and post-natal dexamethasone [RR for BPD or mortality; 0.76; 95% CI 0.66-0.87]. Although early caffeine therapy is now a widely used strategy to prevent BPD, the potentially severe side effects of post-natal glucocorticoids and the concerns regarding the cost-benefit of vitamin A have led to inconsistent use of these drugs in clinical practice. Inhaled bronchodilators and diuretics provide differing degrees of symptomatic relief for patients according to their phenotypic pattern of lung injury; however, these medications do not prevent BPD. Currently available pharmaceuticals do not sufficiently address the degree of structural immaturity and immune dysregulation that is present in the growing population of survivors born prior to 25 weeks gestational age. In this article, we provide both an evidence-based summary of pharmacological treatments currently available to prevent and manage BPD and a discussion of emerging therapies that could help preserve normal lung development in infants born preterm.

Decoding bronchopulmonary dysplasia in premature infants through an epigenetic lens

This review provides a comprehensive overview of the evolving insights into the epigenetic mechanisms associated with bronchopulmonary dysplasia (BPD). It specifically highlights the roles of DNA methylation, histone modifications, and RNA regulation in the development of BPD in premature infants. BPD results from complex interactions among genetic factors, environmental exposures, and neonatal stressors. Key findings suggest that intrauterine hypoxia, hyperoxia, and nutrition can lead to epigenetic alterations, affecting gene expression and methylation, which may serve as biomarkers for early BPD detection. RUNX3 is identified as a critical transcription factor influencing lung development and inflammation, while changes in DNA methylation and histone dynamics in cord blood are linked to immune dysregulation associated with BPD. The role of m6A RNA methylation regulators from the IGF2BP family affects mRNA stability and gene expression relevant to BPD. Additionally, specific histones and microRNAs, particularly from the miR-17∼92 cluster, are implicated in pulmonary development and vascular regulation. Long non-coding RNAs (lncRNAs), such as MALAT1, also play a role in gene regulation via competitive endogenous RNA networks, indicating their potential as biomarkers and therapeutic targets. The interplay of these epigenetic mechanisms underscores the need for further research to develop targeted interventions aimed at reducing BPD severity and enhancing health outcomes for at-risk neonates.

Accuracy of point-of-care nasopharyngeal Interleukin 6 and lung ultrasound in predicting the development of bronchopulmonary dysplasia in preterm infants born before 30 weeks of gestation

Background Bronchopulmonary dysplasia (BPD) is a common cause of morbidity in preterm infants, leading to long-term respiratory complications and risk of neurodevelopmental impairment. Although it has a multifactorial etiology, local inflammation may play a major role.

OBJECTIVES

We aimed to analyze the relationship between nasopharyngeal aspirate (NA) interleukin 6 (IL6) levels and clinical and imaging findings of BPD.

METHODS

Pilot study in preterm infants < 30 weeks. NA was collected at 7 days of life (DOL) and serial lung ultrasounds (LUS) were performed during admission. NA-IL6 levels were measured using an automated electrochemiluminescence immune-analyzer Cobas-e602 and an IL6 ELISA method.

RESULTS

Forty-two patients were studied. Infants with BPD had significantly lower gestational age and higher levels of NA-IL6 at DOL 7. Both methods showed good agreement: ICC = 0.937 (95%CI 0.908-0.957); p < 0.001) and Passing-Bablok Regression (R2 = 0.961). LUS score (AUC = 0.83) and NA-IL6 (AUC = 0.81) at DOL 7 predicted BPD. The AUC of NA-IL6 as a stand-alone marker of BPD was 0.808 (95% CI 0.67 - 0.94); p = 0.002, with 24 pg/ml being the best cutoff with a sensitivity and specificity of 83.3%. A model including birth weight, LUS score at DOL7, NA-IL6 at DOL7, and days of mechanical ventilation predicted BPD with R2 = 0.600 (p < 0.001).

CONCLUSIONS

Point-of-care assessment of NA-IL6 is feasible and reliable compared with a reference method and can be useful in managing BPD. Predictive models of BPD in the first week of life, including clinical, biological, and imaging biomarkers must be tested in larger cohorts.

Outcomes of Ventilator-Dependent Children With Severe Bronchopulmonary Dysplasia and Tracheobronchomalacia

OBJECTIVES

To characterize an observational cohort of ventilator-dependent infants and children with bronchopulmonary dysplasia (BPD) with or without tracheobronchomalacia (TBM) and determine the impact of TBM on the need for ventilator support, liberation from the ventilator and tracheostomy decannulation.

METHODS

Demographics and clinical outcomes were obtained by retrospective review from 12 centers participating in the outpatient BPD Collaborative registry. The cohort consisted of infants born between 2016 and 2021 who were dependent on invasive mechanical ventilation at home. The respiratory outcomes of those infants with TBM were compared to those who did not have TBM.

RESULTS

There were 154 subjects included and about half (48.7%) had documented TBM. Both the TBM and non-TBM groups had similar demographic characteristics and respiratory outcomes. However, the non-TBM were found to have lower mean birth weight (673 vs. 832 grams; p = 0.006), higher likelihood of having Nissen fundoplication (34.2% vs. 12.2%; p = 0.006) and higher use of diuretics (59.2% vs. 37.3%; p = 0.007). Both groups were similar in terms of ventilator requirements, timing of liberation from the ventilator, and rate of decannulation.

CONCLUSIONS

The presence of TBM in ventilator-dependent infants with BPD did not affect ventilator support needs, liberation from the ventilator and the rate of tracheostomy decannulation. We speculate that the relative contributions of the other components of BPD disease may play critical roles in determining the need for tracheostomy and their ultimate respiratory outcomes. A prospective multicenter study to assess the impact of TBM in severe BPD is urgently needed.

Physiologic Pulmonary Phenotyping of Infants Born Preterm and Post-Discharge Respiratory Morbidity

OBJECTIVE

To determine whether airway and parenchymal function identifies subgroups of infants born preterm according to the predominant pulmonary pathophysiology, and whether these subgroups have different risks for respiratory disease during infancy.

STUDY DESIGN

We prospectively enrolled a cohort of 125 infants born preterm with planned clinical follow-up after neonatal intensive care unit discharge. The study included monthly questionnaires for wheeze and visits to a physician or care provider for any respiratory illness. In addition, infant lung function testing near 5 months corrected-age included measures of airways and parenchymal function using forced expiratory flows, alveolar volume (VA), and the carbon monoxide transfer constant (diffusion capacity of lung [DL]/VA). Phenotypes were defined using 2 approaches: an a priori defined phenotypes based on forced expiratory flow 75% and DL/VA z-scores, and an unbiased approach to classifying infants using k-means clustering.

RESULTS

We identified 4 pulmonary physiologic phenotypes that distinguished participants with predominantly decreased airway and/or parenchymal function. Although the worst physiologic phenotypes were associated with a lower gestational age at birth, these phenotypes had a better predictive value than gestational age, sex, and diagnosis of bronchopulmonary dysplasia for increased respiratory morbidity during infancy (area under the curve = 0.71 vs 0.63 for respiratory illness and 0.69 vs 0.63 for wheeze).

CONCLUSIONS

Physiologic pulmonary phenotypes of infants born preterm were associated with differential risks for respiratory morbidities as infants, which may identify heterogeneous risks for long-term respiratory sequelae to individualize therapeutic strategies.

Predicting Clinical Outcomes of Severe Bronchopulmonary Dysplasia through New Definitions and Phenotypes

This study aimed to compare the accuracy of three newly proposed definitions of bronchopulmonary dysplasia (BPD) in predicting outcomes, and to investigate the impact of large airway versus parenchymal versus vascular BPD phenotypes on BPD outcomes.Retrospective chart review of 100 infants with severe BPD discharged from a Children's hospital between 2020 and 2021. Multivariable models evaluated the associations between BPD definitions and phenotypes with tracheostomy and death at 6 months and 1 year after NICU discharge. Secondary outcomes included the need for respiratory support, the use of pulmonary medications, and the need for long-term gastrostomy feeding.Neonatal research network (NRN) and BPD collaborative criteria best-predicted outcomes associated with tracheostomy and/or death (p < 0.001). Among the three BPD phenotypes, large airway disease was independently associated with death or tracheostomy (odds ratios [OR]: 10.5; 95% confidence interval [CI]: 1.6, 68.1). The combination of all three phenotypes was also associated with death or tracheostomy (OR: 9.8; 95% CI: 1.0, 93.5). Both NRN and BPD collaborative definitions showed an association with the need for respiratory support, medication use, and need for long-term gastrostomy tube feeding. Among the 29 infants for whom complete information was available, 18 (62%), 20 (69%), and 18 (62%) had parenchymal, central airway and pulmonary vascular phenotype, respectively.Our results indicate that newer definitions of BPD may better predict the severity of BPD and the need for long-term invasive ventilation support compared with the 2001 National Institute of Health definition of BPD phenotypes impacting mortality and short-term outcomes. These data may be useful for counseling families and developing phenotype-based individualized treatment plans. · The current definition of BPD has limitations.. · New definitions of BPD better predict outcomes.. · BPD phenotypes can better predict outcomes..

Long-term respiratory consequences of prematurity

Approximately 10% of all children worldwide are born preterm and respiratory consequences are amongst the most common sequelae of preterm birth. Except for a higher prevalence of respiratory symptoms and hospital admissions, preterm birth is associated with lower lung function that may track into adulthood. Lung function impairment is not restricted to extreme or very preterm-born subjects as also children born moderate-late preterm have lower Z-scores for lung function. Given the heterogeneity of prematurity-associated lung disease, phenotype-based, multidisciplinary management is needed to improve respiratory health in preterm-born subjects.

Modifiable and Non-Modifiable Risk Factors for Tracheostomy in Preterm Infants

OBJECTIVE

To identify risk factors for tracheostomy among infants born < 33 week gestational age.

METHODS

We conducted a retrospective matched case-control study of infants < 33 week gestation who underwent tracheostomy between 2000 and 2018 at a single level IV NICU. For each case, we identified two controls matched for gestational age ± 1 week and birthweight ± 100 g who were admitted during the same year. Records were reviewed for IMV duration, number of intubations/extubations, postnatal steroid exposure, BPD severity and other clinical factors. Odds ratios and 95% CI were calculated by a conditional logistic regression.

RESULTS

The mean (SD) gestation of the cohort (30 tracheostomy cases; 60 controls) was 26.2 (2.2) week. Tracheostomies were performed at 158 d (127-183) of age and 48 week (44.6-55) post-menstrual age (PMA) following 92 d (64-134) IMV; median (IQR). Tracheostomy was indicated for severe BPD [N = 19(68%)], acquired airway obstruction [N = 4(14%)], or severe BPD with airway obstruction [N = 5(18%)]. Additional risk factors included male sex, outborn birth, intrauterine growth retardation, pulmonary hypertension, and sepsis. IMV duration and length of stay were longer, postnatal steroid exposure was more common and PMA at discharge was later for tracheostomy cases than controls. The number of intubations, extubations (planned and unplanned) and extubations adjusted for IMV duration were significantly higher in cases than controls. In the final logistic model, the number of unplanned extubations and steroid courses were independently associated with tracheostomy.

CONCLUSION

Strategies to minimize tracheostomy risk should target modifiable risk factors such as reducing unplanned extubations and limiting postnatal steroids in high-risk infants.

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.

Clinical Outcomes Through Two Years for Infants With Bronchopulmonary Dysplasia and Tracheomalacia

BACKGROUND

Tracheomalacia (TM) is common in infants with bronchopulmonary dysplasia (BPD) and associated with respiratory morbidity. Assessment of TM was historically via bronchoscopy, but recent studies demonstrate that ultrashort echo-time (UTE) magnetic resonance imaging (MRI) can accurately assess TM in neonates.

RESEARCH QUESTION

Do neonates with MRI-identified TM and BPD have increased respiratory morbidity through age 2 years?

METHODS

We performed an observational cohort study of 54 subjects with BPD and assessed TM using UTE MRI at term-equivalent age. TM was defined as an airway minor/major axis ratio (rd,min) of < 0.7. Outcomes through 2 years of life were evaluated via electronic medical record review.

RESULTS

There were 23 subjects (43%) with TM. Modified Ochiai MRI scores were similar between the subjects with and without TM (7.3 ± 4.1 vs. 7.4 ± 4.1). Subjects with TM were more likely to require respiratory support at age 2 years (62% vs. 30%, p = 0.04) and be prescribed systemic corticosteroids (71% vs. 27%, p = 0.004). Most patients with TM were prescribed bronchodilators (90% vs. 60%, p = 0.04). A 10% increase in tracheal collapse correlated with a 28-day increased hospital length of stay (p = 0.047), increased likelihood of pneumonia (p = 0.05), and treatment with antibiotics (p = 0.04) and systemic steroids (p = 0.008).

CONCLUSIONS

TM in the neonatal period was associated with increased respiratory morbidity through age 2 years, demonstrated by increased respiratory support and more frequent usage of systemic corticosteroids and bronchodilators, independent of the severity of BPD. These results highlight the significance of central airway disease in neonates with BPD.

Airway diseases in very low birth weight infants

OBJECTIVE

To identify the incidence and characteristics of airway diseases in very low birth weight infants (VLBWIs).

METHODS

A retrospective study of 214 inborn VLBWIs admitted to our NICU between April 2009 and March 2022 (approval no: 2023-0008). Neonatologists ourselves performed bronchoscopy to diagnose airway diseases.

RESULTS

Symptomatic airway diseases were present in 36/214 (16.8%) of VLBWIs. Common airway diseases were tracheobronchomalacia (TBM) and pharyngomalacia. Infants with airway diseases had shorter gestational age, lower birth weight, more boys, and more moderate/severe bronchopulmonary dysplasia (BPD). Regarding treatment, more infants with airway diseases required intubation were intubated longer, used more dexamethasone, were on ventilators and oxygen longer, and were hospitalized longer.

CONCLUSION

We found that VLBWIs were more frequently complicated with airway diseases, especially TBM. We also observed many pharyngeal lesions, which have not been previously reported. Intensity of prematurity, BPD, and the need for stronger respiratory management were risks for airway diseases. In VLBWIs, bronchoscopy should be actively performed because airway diseases are important complications.

The cross-talk between the metabolome and microbiome in a double-hit neonatal rat model of bronchopulmonary dysplasia

Bronchopulmonary dysplasia (BPD), a chronic lung disease in preterm infants, is associated with inflammation and high oxygen exposure. However, the effects of antenatal inflammation and postnatal extended hyperoxia on the metabolome and microbiome remain unclear. In this study, pregnant rats received lipopolysaccharide or saline injections on gestational day 20 and were exposed to either 21 % or 80 % oxygen for 4 weeks post-birth. Analysis revealed an increase in Firmicutes, Proteobacteria, and Actinobacteria, with a decrease in Bacteroidetes in BPD rats. Metabolomic analysis identified 78 altered metabolites, primarily lipids, enriched in pathways including arginine biosynthesis, sphingolipid metabolism, and primary bile acid biosynthesis in BPD rats. Integration analysis revealed strong correlations between intestinal microbiota and metabolites in BPD rats. These findings underscored the impact of antenatal inflammation and prolonged postnatal hyperoxia on gut microbiota and serum metabolome, suggesting their role in BPD pathogenesis.

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.

Correlating Severity of Pulmonary Hypertension by Echocardiogram with Mortality in Premature Infants with Bronchopulmonary Dysplasia

OBJECTIVE

 Bronchopulmonary dysplasia (BPD) is the most common complication of preterm birth. Infants with BPD are at increased risk for pulmonary hypertension (PH). Cardiac catheterization is the gold standard for diagnosing PH, but cardiac catheterization is challenging to perform in small, sick, premature infants. The utility of echocardiography for diagnosing PH and predicting outcomes in extremely premature infants has not been clearly defined. Therefore, we sought to use predefined criteria to diagnose PH by echocardiogram and relate PH severity to mortality in extremely premature infants with BPD.

STUDY DESIGN

 Echocardiograms from 46 infants born ≤28 weeks' postmenstrual age with a diagnosis of BPD were assessed for PH by three pediatric cardiologists using predefined criteria, and survival times among categories of PH patients were compared. A total of 458 echocardiograms were reviewed, and 15 (33%) patients were found to have at least moderate PH. Patients with at least moderate PH had similar demographic characteristics to those with no/mild PH.

RESULTS

 Ninety percent of infants without moderate to severe PH survived to hospital discharge, compared with 67% of infants with at least moderate PH (p = 0.048). Patients with severe PH had decreased survival to hospital discharge (38%) compared with moderate (100%) and no/mild PH (90%) groups. Kaplan-Meier survival curves also differed among PH severity groups (Wilcoxon p < 0.001).

CONCLUSION

 Using predefined criteria for PH, premature infants with BPD can be stratified into PH severity categories. Patients diagnosed with severe PH by echocardiogram have significantly reduced survival.

KEY POINTS

· A composite score definition of PH by echocardiogram showed high inter- and intrarater reliability.. · Infants with severe PH by echocardiogram had decreased survival rates.. · Early diagnosis of PH by echocardiogram dictates treatment which may improve outcomes..

Implication of m6A Methylation Regulators in the Immune Microenvironment of Bronchopulmonary Dysplasia

N6-methyladenosine (m6A) regulates gene expression and governs many important biological processes. However, the function of m6A in the development of bronchopulmonary dysplasia (BPD) remains poorly characterized. Thus, the purpose of this investigation was to evaluate the effects of m6A RNA methylation regulators on the development of BPD. BPD-related transcriptome data were downloaded from the GEO database. Differentially expressed m6A methylation regulators between BPD and control group were identified. Consensus clustering was conducted for the classification of BPD and association between clusters and BPD phenotypes were explored. Analysis of differentially expressed genes (DEGs) and immune-related DEGs was performed. The GSEA, GO and KEGG analyses were used to interpret the functional enrichments. The composition of immune cell subtypes in BPD subsets was predicted by CIBERSORT analysis. Compared with the control group, expression of most m6A regulators showed significant alteration, especially for IGF2BP1/2/3. BPD was classified into 2 subsets, and cluster 1 was correlated with severe BPD. Furthermore, the results of functional enrichment analyses showed a disturbed immune-related signaling pathway. Based on CIBERSORT analysis, we found that the proportion of immune cell subsets changed between cluster 1 and cluster 2. Our study revealed the implication of m6A methylation regulators in the development of BPD, which might provide a novel insight for the diagnosis and treatment of BPD.

Achieved oxygen saturations and risk for bronchopulmonary dysplasia with pulmonary hypertension in preterm infants

OBJECTIVE

Characterisation of oxygen saturation (SpO2)-related predictors that correspond with both bronchopulmonary dysplasia-associated pulmonary hypertension (BPD-PH) development and survival status in infants with BPD-PH may improve patient outcomes. This investigation assessed whether (1) infants with BPD-PH compared with infants with BPD alone, and (2) BPD-PH non-survivors compared with BPD-PH survivors would (a) achieve lower SpO2 distributions, (b) have a higher fraction of inspired oxygen (FiO2) exposure and (c) have a higher oxygen saturation index (OSI).

DESIGN

Case-control study between infants with BPD-PH (cases) and BPD alone (controls) and by survival status within cases.

SETTING

Single-centre study in the USA.

PATIENTS

Infants born at <29 weeks' gestation and on respiratory support at 36 weeks' postmenstrual age.

EXPOSURES

FiO2 exposure, SpO2 distributions and OSI were analysed over the week preceding BPD-PH diagnosis.

MAIN OUTCOMES AND MEASURES

BPD-PH, BPD alone and survival status in infants with BPD-PH.

RESULTS

40 infants with BPD-PH were compared with 40 infants with BPD alone. Infants who developed BPD-PH achieved lower SpO2 compared with infants with BPD (p<0.001), were exposed to a higher FiO2 (0.50 vs 0.34; p=0.02) and had a higher OSI (4.3 vs 2.6; p=0.03). Compared with survivors, infants with BPD-PH who died achieved a lower SpO2 (p<0.001) and were exposed to a higher FiO2 (0.70 vs 0.42; p=0.049).

CONCLUSIONS

SpO2-related predictors differed between infants with BPD-PH and BPD alone and among infants with BPD-PH by survival status. The OSI may provide a non-invasive predictor for BPD-PH in preterm infants.

Impact of severity and age with variable definitions of bronchopulmonary dysplasia on neurodevelopmental outcomes

BACKGROUND

Bronchopulmonary dysplasia (BPD) is associated with neurodevelopmental impairment (NDI).

METHODS

To compare the ability of NICHD 2001 and Jensen 2019 definitions of BPD and respiratory support at 40 weeks postmenstrual age (PMA) to predict NDI, a retrospective study (1/2010-12/2020) was conducted in infants with gestational age <32 weeks and birth weight <1500 g. The primary outcome measure was NDI at 18-24 months corrected age.

RESULTS

Of 1119 infants, 227 (20.7%) met the inclusion criteria and had adequate follow-up data. Multivariate regression analysis showed that the NICHD 2001 definition was not predictive of NDI. Infants with Grade 2 or 3 BPD (Jensen 2019) had 4.75 (95% CI: 1.282-17.563) times greater odds of having NDI than infants without BPD. Infants requiring respiratory support at 40 weeks PMA had 4.95 (95% CI: 1.490-16.47) times greater odds of having NDI. Receiver operating characteristic curves demonstrated that the 2 definitions of BPD and the need for respiratory support at 40 weeks PMA were similar in their ability to predict NDI.

CONCLUSION

There is no significant difference in the ability of the NICHD 2001 and Jensen 2019 BPD definitions, as well as the need for respiratory support at 40 weeks, for predicting NDI.

IMPACT STATEMENT

Current bronchopulmonary dysplasia (BPD) definitions may not effectively predict neurodevelopmental impairment (NDI) in preterm infants. Grades 2/3 BPD (Jensen 2019 criteria) significantly associate with NDI. Infants requiring respiratory support at 40 weeks post-menstrual age (PMA) have 5 times higher odds of NDI than those on room air at 40 weeks PMA. The NICHD 2001, Jensen 2019 definitions, and the requirement for respiratory support at 40 weeks PMA, do not differ in their ability to predict NDI. Future studies should include multiple centers, with level III-IV NICUs, catering to socioeconomic, culturally, and racially diverse populations.

Lower peripheral blood CD4+ lymphocyte ratio is associated with severe bronchopulmonary dysplasia

OBJECTIVE

To elucidate the characteristics of lymphocyte subsets in bronchopulmonary dysplasia (BPD) diagnosis following Jensen's criterion to understand the spectrum of lymphocytes in different degrees of BPD.

STUDY DESIGN

This single-center retrospective cohort study included 120 neonates admitted to the neonatal intensive care unit between 1 July 2014 and 30 June 2021, who had undergone peripheral blood lymphocyte subpopulation detection.

RESULTS

Thirty-one neonates were included in the control group, whereas 33 infants with BPD were included in the case group. In addition, we selected 56 infants with a gestational age (GA) <37 weeks without BPD who were receiving oxygen therapy. Among the three groups, the B cell and NK cell frequencies were significantly higher and the frequencies of T cells and CD4+ cells were significantly lower in the BPD group. In newborns without BPD, the distribution of T lymphocyte subsets was similar at different GAs. Comparing different degrees of BPD, the patients in the grades 2-3 BPD group had significantly lower percentages of T lymphocytes and CD4+ T cells than those in the other groups. Remarkably, the frequencies of NK cells were significantly higher in patients with grades 2-3 BPD, and the Treg cells slightly increased with BPD severity, although the differences were not significant.

CONCLUSION

Healthy neonates had similar ratios of lymphocyte subsets among different GAs; although as the GAs increased, the percentage of lymphocytes increased slightly. Severe BPD was associated with lower CD4+ T cells and higher NK cells. However, whether such changes were the cause or the consequence of BPD has not been determined.

Continuous Neuromuscular Blockade for Bronchopulmonary Dysplasia

OBJECTIVE

 Bronchopulmonary dysplasia (BPD) is the most common late morbidity for premature infants. Continuous neuromuscular blockade (CNMB) is suggested for the most unstable phase of BPD, despite no outcome data. We explored the association between duration of CNMB for severe BPD and mortality.

DESIGN

 Medical record review of children <5 years old admitted from 2016 to 2022 with BPD and one or more course of CNMB for ≥14 days.

RESULTS

 Twelve children received a total of 20 episodes of CNMB for ≥14 days (range 14-173 d) during their hospitalization. Most (10/12) were born at <28 weeks' gestation and most (11/12) with birth weight <1,000 g; 7/12 were of Black race/ethnicity. All were hospitalized since birth. Most (10/12) were initially transferred from an outside neonatal intensive care unit (ICU), typically after a >60-day hospitalization (9/12). Half (6/12) of them had a ≥60-day stay in our neonatal ICU before transferring to our pediatric ICU for, generally, ≥90 days (8/12). The primary study outcome was survival to discharge: 2/12 survived. Both had shorter courses of CNMB (19 and 25 d); only one child who died had a course ≤25 days. Just two infants had increasing length Z-scores during hospitalization; only one infant had a final length Z-score > - 2.

CONCLUSION

 In this case series of infants with severe BPD, there were no survivors among those receiving ≥25 days of CNMB. Linear growth, an essential growth parameter for infants with BPD, decreased in most patients. These data do not support the use of ≥25 days of CNMB to prevent mortality in infants with severe BPD.

KEY POINTS

· This is a case series of neuromuscular blockade for severe BPD.. · Neuromuscular blockade did not improve linear growth.. · Ten out of 12 infants who were on prolonged neuromuscular blockade died..

Monitoring lung and cerebral oxygenation using near-infrared spectroscopy in preterm infants during kangaroo mother care

Lung function has never been assessed during kangaroo mother care (KMC) in preterm infants. We measured lung (rSO2L) and cerebral (rSO2C) oxygenation by near-infrared spectroscopy (NIRS) in infants born at less than 32 weeks of gestation or weighing ≤ 1500 g during KMC. rSO2L, rSO2C, and pulmonary (FOEL) and cerebral (FOEC) tissue oxygen extraction fraction were measured in 20 preterm infants before, during, and after a 2-h period of KMC at a mean postnatal age of 36 ± 21 days of life. We found that rSO2L, rSO2C, FOEL, and FOEC did not change in our patients. After 120 min of KMC, rSO2L was lower (71.3 ± 1.4 vs. 76.7 ± 4.6%; P = 0.012) in infants with BPD (n = 6; 30%) than in infants without BPD (n = 14 = 60%), while FOEL was higher (0.26 ± 0.02 vs. 0.20 ± 0.05; P = 0.012).Conclusion: Cerebral and lung oxygenation did not change in preterm infants during KMC. A transient decrease in lung oxygenation was offset by the increase in oxygen extraction, but these changes were clinically insignificant. These results confirm the safety of KMC in preterm infants who are in stable clinical conditions. What is Known • Kangaroo mother care (KMC) is widely used to improve the care of preterm newborns since it improves their outcome. • KMC is safe as patients' vital parameters, are not negatively affected, but lung function has never been directly assessed. What is New • Cerebral and lung oxygenation measured by near-infrared spectroscopy did not change during KMC. • A transient decrease in lung oxygenation compensated for by the increase in oxygen extraction occurred only in infants with BPD, but these changes were clinically insignificant.

Bronchopulmonary Dysplasia

Bronchopulmonary dysplasia (BPD) is a chronic lung disease, associated with premature birth, that arises during the infantile period. It is an evolving disease process with an unchanged incidence due to advancements in neonatal care which allow for the survival of premature infants of lower gestational ages and birth weights. Currently, there are few effective interventions to prevent BPD. However, careful attention to BPD phenotypes and comprehensive care provided by an interdisciplinary team have improved care. Interventions early in the disease course hold promise for improving long-term survival and outcomes in adulthood for this high-risk population.

The respiratory consequences of preterm birth: from infancy to adulthood

Survival of preterm-born infants, especially at extremes of prematurity (less than 28 weeks gestation), is now common, particularly in the developed world. Despite advances in neonatal care, short-term respiratory morbidity, termed bronchopulmonary dysplasia (also called chronic lung disease of prematurity), remains an important clinical outcome. As survival during the neonatal period has improved, preterm-born individuals are now entering childhood, adolescence and adulthood in far greater numbers, and adverse longer-term respiratory outcomes following birth at an immature stage of lung development are becoming increasingly apparent. In this article, we shall review the background of the major respiratory complications in the neonatal period, bronchopulmonary dysplasia, and the current evidence regarding its prevention and management. In addition, we shall review the emerging literature on the respiratory morbidity experienced in childhood, adolescence, and adulthood by preterm-born survivors, with reduced lung function and a risk of developing chronic obstructive pulmonary disease in early adult life. As this population of preterm-born individuals increases, an understanding of the respiratory consequences of preterm birth will become increasingly important not only for neonatologists, paediatricians and paediatric pulmonologists but also for physicians and healthcare professionals involved in the care of adults who were born preterm.

Interdisciplinary clinical bronchopulmonary dysplasia programs: development, evolution, and maturation

Multidisciplinary bronchopulmonary dysplasia (BPD) programs provide improved and consistent medical management, care of the developing infant, family support, and smoother transitions in care resulting in improved survival, pulmonary, and extra-pulmonary outcomes. This review summarizes the benefits of interdisciplinary BPD management, as well as strategies for initial programmatic development, program growth, and maintenance at centers across the United States factoring in institutional, provider, and parent reported goals that were derived from a consensus conference on BPD management.

Assessing the role of tracheostomy placement in bronchopulmonary dysplasia with pulmonary hypertension

OBJECTIVE

Bronchopulmonary dysplasia (BPD) is a common complication of preterm birth and is associated with abnormal vasculature that contributes to pulmonary hypertension (PH). We evaluated how a tracheostomy may alter PH in these patients.

METHODS

A retrospective chart review over 15-years identified 17 patients with BPD and PH who underwent tracheostomy. Each patient had four echocardiograms re-reviewed and scored for tricuspid valve regurgitation velocity (TR), tricuspid annular plane systolic excursion (TAPSE), right atrial cross-sectional area (RACA), and left ventricle eccentricity indices (EI).

RESULT

There was improvement in TR, TAPSE, RACA, and left ventricle EI indicating reduction in PH after tracheostomy.

CONCLUSION

PH improves over time though role of tracheostomy in PH needs to be further defined. The EI may be a sensitive marker to follow over time in these patients.

Bronchopulmonary Dysplasia-Associated Pulmonary Hypertension: Basing Care on Physiology

Bronchopulmonary dysplasia (BPD) is the heterogeneous chronic lung developmental disease of prematurity, which is often accompanied by multisystem comorbidities. Pulmonary vascular disease and pulmonary hypertension (PH) contribute significantly to the pathogenesis and pathophysiology of BPD and dramatically influence the outcomes of preterm infants with BPD. When caring for those patients, clinicians should consider the multitude of phenotypic presentations that fall under the "BPD-PH umbrella," reflecting the need for matching therapies to specific physiologies to improve short- and long-term outcomes. Individualized management based on the patient's prenatal and postnatal risk factors, clinical course, and cardiopulmonary phenotype needs to be identified and prioritized to provide optimal care for infants with BPD-PH.

Measurement of lung oxygenation by near-infrared spectroscopy in preterm infants with bronchopulmonary dysplasia

INTRODUCTION

It has recently been reported that it is possible to monitor lung oxygenation (rSO2L) by near-infrared spectroscopy (NIRS) in preterm infants with respiratory distress syndrome (RDS). Thus, our aim was to assess the possibility of monitoring rSO2L in infants with evolving and established bronchopulmonary dysplasia (BPD) and to evaluate if rSO2L correlates with BPD severity and other oxygenation indices.

METHODS

We studied 40 preterm infants with gestational age ≤30 weeks at risk for BPD. Patients were continuously studied for 2 h by NIRS at 28 ± 7 days of life and 36 weeks ± 7 days of postmenstrual age.

RESULTS

rSO2L was similar at the first and second NIRS recordings (71.8 ± 7.2 vs. 71.4 ± 4.2%) in the overall population, but it was higher in infants with mild than in those with moderate-to-severe BPD at both the first (73.3 ± 3.1 vs. 71.2 ± 3.2%, p = .042) and second (72.3 ± 2.8 vs. 70.5 ± 2.8, p = .049) NIRS recording. A rSO2L cutoff value of 71.6% in the first recording was associated with a risk for moderate-to-severe BPD with a sensitivity of 66% and a specificity of 60%. Linear regression analysis demonstrated a significant positive relationship between rSO2L and SpO2/FiO2 ratio (p = .013) and a/APO2 (p = .004).

CONCLUSIONS

Monitoring of rSO2L by NIRS in preterm infants with evolving and established BPD is feasible and safe. rSO2L was found to be higher in infants with mild BPD, and predicts the risk for developing moderate-to-severe BPD and correlates with other indices of oxygenation.

Validating the Physician Documentation Quality Instrument for Intensive Care Unit-Ward Transfer Notes

Background

Physician communication failures during transfers of patients from the intensive care unit (ICU) to the general ward are common and can lead to adverse events. Efforts to improve written handoffs during these transfers are increasingly prominent, but no instruments have been developed to assess the quality of physician ICU-ward transfer notes.

Objective

To collect validity evidence for the modified nine-item Physician Documentation Quality Instrument (mPDQI-9) for assessing ICU-ward transfer note usefulness across several hospitals.

Methods

Twenty-four physician raters independently used the mPDQI-9 to grade 12 notes collected from three academic hospitals. A priori, we excluded the "up-to-date" and "accurate" domains, because these could not be assessed without giving the rater access to the complete patient chart. Assessments therefore used the domains "thorough," "useful," "organized," "comprehensible," "succinct," "synthesized," and "consistent." Raters scored each domain on a Likert scale ranging from 1 (low) to 5 (high). The total mPDQI-9 was the sum of these domain scores. The primary outcome was the raters' perceived clinical utility of the notes, and the primary measures of interest were criterion validity (Spearman's ρ) and interrater reliability (intraclass correlation [ICC]).

Results

Mean mPDQI-9 scores by note ranged from 19 (SD = 5.5) to 30 (SD = 4.2). Mean note ratings did not systematically differ by rater expertise (for interaction, P = 0.15). The proportion of raters perceiving each note as independently sufficient for patient care (the primary outcome) ranged from 33% to 100% across the set of notes. We found a moderately positive correlation between mPDQI-9 ratings and raters' overall assessments of each note's clinical utility (ρ = 0.48, P < 0.001). Interrater reliability was strong; the overall ICC was 0.89 (95% confidence interval [CI], 0.80-0.85), and ICCs were similar among reviewer groups. Finally, Cronbach's α was 0.87 (95% CI, 0.84-0.89), indicating good internal consistency.

Conclusions

We report moderate validity evidence for the mPDQI-9 to assess the usefulness of ICU-ward transfer notes written by internal medicine residents.

ATS core curriculum 2023. Pediatric pulmonary medicine: Respiratory disorders in infants

The American Thoracic Society Core Curriculum updates clinicians annually in pediatric pulmonary disease. This is a summary of the Pediatric Pulmonary Medicine Core Curriculum presented at the 2023 American Thoracic Society International Conference. The respiratory disorders of infancy discussed in this year's review include: the care of the patient with bronchopulmonary dysplasia in the neonatal intensive care unit, clinical phenotypes and comorbidities; diffuse lung disease; pulmonary hypertension; central and obstructive sleep apnea. The care of infants with respiratory disorders often poses significant challenges to the general pediatric pulmonologist, sleep clinician, and neonatologist. This review aims to highlight the most clinically relevant aspects of the evaluation, management, and outcomes of infants with these key respiratory disorders, while emphasizing the importance of multidisciplinary care. Furthermore, this document summarizes essential aspects of genetic testing, novel imaging and treatment modalities, and includes multiple resources for clinical practice.

Rates of bronchopulmonary dysplasia in very low birth weight neonates: a systematic review and meta-analysis

IMPORTANCE

Large-scale estimates of bronchopulmonary dysplasia (BPD) are warranted for adequate prevention and treatment. However, systematic approaches to ascertain rates of BPD are lacking.

OBJECTIVE

To conduct a systematic review and meta-analysis to assess the prevalence of BPD in very low birth weight (≤ 1,500 g) or very low gestational age (< 32 weeks) neonates.

DATA SOURCES

A search of MEDLINE from January 1990 until September 2019 using search terms related to BPD and prevalence was performed.

STUDY SELECTION

Randomized controlled trials and observational studies evaluating rates of BPD in very low birth weight or very low gestational age infants were eligible. Included studies defined BPD as positive pressure ventilation or oxygen requirement at 28 days (BPD28) or at 36 weeks postmenstrual age (BPD36).

DATA EXTRACTION AND SYNTHESIS

Two reviewers independently conducted all stages of the review. Random-effects meta-analysis was used to calculate the pooled prevalence. Subgroup analyses included gestational age group, birth weight group, setting, study period, continent, and gross domestic product. Sensitivity analyses were performed to reduce study heterogeneity.

MAIN OUTCOMES AND MEASURES

Prevalence of BPD defined as BPD28, BPD36, and by subgroups.

RESULTS

A total of 105 articles or databases and 780,936 patients were included in this review. The pooled prevalence was 35% (95% CI, 28-42%) for BPD28 (n = 26 datasets, 132,247 neonates), and 21% (95% CI, 19-24%) for BPD36 (n = 70 studies, 672,769 neonates). In subgroup meta-analyses, birth weight category, gestational age category, and continent were strong drivers of the pooled prevalence of BPD.

CONCLUSIONS AND RELEVANCE

This study provides a global estimation of BPD prevalence in very low birth weight/low gestation neonates.

Approaches to Interdisciplinary Care for Infants with Severe Bronchopulmonary Dysplasia: A Survey of the Bronchopulmonary Dysplasia Collaborative

OBJECTIVE

Bronchopulmonary dysplasia (BPD) remains the most common late morbidity for extremely premature infants. Care of infants with BPD requires a longitudinal approach from the neonatal intensive care unit to ambulatory care though interdisciplinary programs. Current approaches for the development of optimal programs vary among centers.

STUDY DESIGN

We conducted a survey of 18 academic centers that are members of the BPD Collaborative, a consortium of institutions with an established interdisciplinary BPD program. We aimed to characterize the approach, composition, and current practices of the interdisciplinary teams in inpatient and outpatient domains.

RESULTS

Variations exist among centers, including composition of the interdisciplinary team, whether the team is the primary or consult service, timing of the first team assessment of the patient, frequency and nature of rounds during the hospitalization, and the timing of ambulatory visits postdischarge.

CONCLUSION

Further studies to assess long-term outcomes are needed to optimize interdisciplinary care of infants with severe BPD.

KEY POINTS

· Care of infants with BPD requires a longitudinal approach from the NICU to ambulatory care.. · Benefits of interdisciplinary care for children have been observed in other chronic conditions.. · Current approaches for the development of optimal interdisciplinary BPD programs vary among centers..

Long-term pulmonary outcomes in BPD throughout the life-course

Respiratory disease is one of the most common complications of preterm birth. Survivors of prematurity have increased risks of morbidities and mortalities independent of prematurity, and frequently require multiple medications, home respiratory support, and subspecialty care to maintain health. Although advances in neonatal and pulmonary care have improved overall survival, earlier gestational age, lower birth weight, chorioamnionitis and late onset sepsis continue to be major factors in the development of bronchopulmonary dysplasia. These early life events associated with prematurity can have respiratory consequences that persist into adulthood. Furthermore, after initial hospital discharge, air pollution, respiratory tract infections and socioeconomic status may modify lung growth trajectories and influence respiratory outcomes in later life. Given that the incidence of respiratory disease associated with prematurity remains stable or increased, there is a need for pediatric and adult providers to be familiar with the natural history, manifestations, and common complications of disease.

Types of home respiratory support in children with bronchopulmonary dysplasia and factors determining its duration: A scoping review

Bronchopulmonary dysplasia also known as chronic lung disease of prematurity has changed as a disease entity over the last five decades and children with "new bronchopulmonary dysplasia (BPD)" have better survival rates. This necessitates strategies to prevent severe BPD and provide organized home support. Home respiratory support in these children varies from home oxygen to noninvasive ventilation and tracheostomy ventilation. This review was conducted utilizing Joanna Briggs Institute publications on evidence synthesis and presentation of results for a scoping review. The Preferred Reporting Items for Systematic Review and Meta-Analyses were used to report the results. The risk of bias assessment was done using "The Cochrane Handbook for Systematic Reviews tool for interventional studies." After screening for the duplication of results and applying inclusion and exclusion criteria, twenty-seven studies were assessed by reading the full texts. Out of these, eleven were finally included in this systematic review. The total sample size from all studies was 4794, including 2705 males. The 4/11 studies home oxygen, one study reported continuous positive airway pressure/bilevel positive airway pressure and seven studies used tracheostomy or tracheostomy ventilation. The median duration of post-natal invasive ventilation was higher in those discharged on home oxygen compared to those who did not need oxygen at discharge. There is a significant proportion of children who are tracheostomy ventilated (8.65%) at home. In the absence of established guidelines, these children are vulnerable when it comes to care at home and the timing of decannulation. For home oxygen alone, guidelines by ERS, ATS and BTS have streamlined weaning protocols and the need for having a multi-disciplinary team to care for these children.

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.

Association of the respiratory severity score with bronchopulmonary dysplasia-associated pulmonary hypertension in infants born extremely preterm

OBJECTIVE

To test the hypothesis that elevations in the respiratory severity score (RSS) are associated with increased probability of bronchopulmonary dysplasia-associated pulmonary hypertension (BPD-PH).

STUDY DESIGN

Retrospective cohort study of infants born extremely preterm admitted to a BPD center between 2010 and 2018. Echocardiograms obtained ≥ 36 weeks' post-menstrual age (PMA) were independently adjudicated by two blinded cardiologists to determine the presence/absence of BPD-PH. Multivariable logistic regression estimated the association between RSS and BPD-PH.

RESULT

BPD-PH was observed in 68/223 (36%) of subjects. The median RSS at time of echocardiography was 3.04 (Range 0-18.3). A one-point increase in the RSS was associated with BPD-PH, aOR 1.3 (95% CI 1.2-1.4), after adjustment for gestational age and PMA at time of echocardiography.

CONCLUSION

Elevations in the RSS were associated with a greater probability of BPD-PH. Prospective studies are needed to determine the validity and performance of RSS as a clinical susceptibility/risk biomarker for BPD-PH.

Transpyloric feeding is associated with adverse in-hospital outcomes in infants with severe bronchopulmonary dysplasia

OBJECTIVE

To estimate the association of transpyloric feeding (TPF) with the composite outcome of tracheostomy or death for patients with severe bronchopulmonary dysplasia (sBPD).

STUDY DESIGN

Retrospective multi-center cohort study of preterm infants <32 weeks with sBPD receiving enteral feedings. We compared infants who received TPF at 36, 44, or 50 weeks post-menstrual age to those who did not receive TPF at any of those timepoints. Odds ratios were adjusted for gestational age, small for gestational age, male sex, and invasive ventilation and FiO2 at 36 weeks.

RESULTS

Among 1039 patients, 129 (12%) received TPF. TPF was associated with an increased odds of tracheostomy or death (aOR 3.5, 95% CI 2.0-6.1) and prolonged length of stay or death (aOR 3.1, 95% CI 1.9-5.2).

CONCLUSIONS

Use of TPF in sBPD after 36 weeks was infrequent and associated with worse in-hospital outcomes, even after adjusting for respiratory severity at 36 weeks.

Does faster weight trajectory lead to improved neurodevelopmental outcomes in ELBW infants with bronchopulmonary dysplasia?

OBJECTIVE

Examine the relationship between weight trajectory and 2-year neurodevelopmental outcomes for extremely low birthweight (ELBW) infants with BPD.

STUDY DESIGN

Secondary analysis of infants born from 2010 to 2019. The predictor was BPD severity and the outcome was neurodevelopmental impairment, defined as any Bayley Scales of Infant Development (BSID) III score <70 at 24 months' corrected age. Repeated measures logistic regression was performed.

RESULTS

In total, 5042 infants were included. Faster weight trajectory was significantly associated with a decreased probability of having at least one BSID III score <70 for infants with grade 1-2 BPD (p < 0.0001) and an increased probability of at least one BSID III score <70 for infants with grade 3 BPD (p < 0.009). There was no significant association between weight trajectory and BSID III score <70 for infants with grade 0 BPD.

CONCLUSION

The association between postnatal weight trajectory and neurodevelopmental outcome in this study differs by BPD severity.

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.

Impact of bronchopulmonary dysplasia on brain GABA concentrations in preterm infants: Prospective cohort study

BACKGROUND

Bronchopulmonary dysplasia (BPD) is associated with cognitive-behavioral deficits in very preterm (VPT) infants, often in the absence of structural brain injury. Advanced GABA-editing techniques like Mescher-Garwood point resolved spectroscopy (MEGA-PRESS) can quantify in-vivo gamma-aminobutyric acid (GABA+, with macromolecules) and glutamate (Glx, with glutamine) concentrations to investigate for neurophysiologic perturbations in the developing brain of VPT infants.

OBJECTIVE

To investigate the relationship between the severity of BPD and basal-ganglia GABA+ and Glx concentrations in VPT infants.

METHODS

MRI studies were performed on a 3 T scanner in a cohort of VPT infants [born ≤32 weeks gestational age (GA)] without major structural brain injury and healthy-term infants (>37 weeks GA) at term-equivalent age. MEGA-PRESS (TE68ms, TR2000ms, 256averages) sequence was acquired from the right basal-ganglia voxel (∼3cm3) and metabolite concentrations were quantified in institutional units (i.u.). We stratified VPT infants into no/mild (grade 0/1) and moderate-severe (grade 2/3) BPD.

RESULTS

Reliable MEGA-PRESS data was available from 63 subjects: 29 healthy-term and 34 VPT infants without major structural brain injury. VPT infants with moderate-severe BPD (n = 20) had the lowest right basal-ganglia GABA+ (median 1.88 vs. 2.28 vs. 2.12 i.u., p = 0.025) and GABA+/choline (0.73 vs. 0.99 vs. 0.88, p = 0.004) in comparison to infants with no/mild BPD and healthy-term infants. The GABA+/Glx ratio was lower (0.34 vs. 0.44, p = 0.034) in VPT infants with moderate-severe BPD than in infants with no/mild BPD.

CONCLUSIONS

Reduced GABA+ and GABA+/Glx in VPT infants with moderate-severe BPD indicate neurophysiologic perturbations which could serve as early biomarkers of future cognitive deficits.

Pulmonary phenotypes of bronchopulmonary dysplasia in the preterm infant

Bronchopulmonary dysplasia (BPD) remains the most common complication of premature birth, imposing a significant and potentially life-long burden on patients and their families. Despite advances in our understanding of the mechanisms that contribute to patterns of lung injury and dysfunctional repair, current therapeutic strategies remain non-specific with limited success. Contemporary definitions of BPD continue to rely on clinician prescribed respiratory support requirements at specific time points. While these criteria may be helpful in broadly identifying infants at higher risk of adverse outcomes, they do not offer any precise information regarding the degree to which each compartment of the lung is affected. In this review we will outline the different pulmonary phenotypes of BPD and discuss important features in the pathogenesis, clinical presentation, and management of these frequently overlapping scenarios.

Bronchopulmonary dysplasia - associated pulmonary hypertension: An updated review

Bronchopulmonary dysplasia (BPD) is the leading cause of chronic lung disease in infants and the commonest complication of prematurity. Advances in respiratory and overall neonatal care have increased the survival of extremely low gestational age newborns, leading to the continued high incidence of BPD. Pulmonary hypertension (PH) represents the severe form of the pulmonary vascular disease associated with BPD, and affects almost one-third of infants with moderate to severe BPD. PH responds suboptimally to pulmonary vasodilators and increases morbidity and mortality in BPD infants. An up-to-date knowledge of the pathogenesis, pathophysiology, diagnosis, treatment, and outcomes of BPD-PH can be helpful to develop meaningful and novel strategies to improve the outcomes of infants with this disorder. Therefore, our multidisciplinary team has attempted to thoroughly review and summarize the latest advances in BPD-PH in preventing and managing this morbid lung disorder of preterm infants.

Respiratory management of established severe bronchopulmonary dysplasia

Respiratory management of infants with established severe BPD is difficult and there is little evidence upon which to base decisions. Nonetheless, the physiology of severe BPD is well described with a predominantly obstructive pattern. This pulmonary dysfunction results in prolonged exhalatory time constants and thus ventilator management must be focused on maintaining adequate oxygenation and ventilation through achieving full exhalation. This approach is often difficult to maintain in acute care settings and a culture of chronic care focused on slow change and steady progress is imperative. Once respiratory stability is achieved, the focus should shift to growth and development and avoidance of care practices and medications that impair neurodevelopment.

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.

Development and Disorders of the Airway in Bronchopulmonary Dysplasia

Bronchopulmonary dysplasia (BPD), a disorder characterized by arrested lung development, is a frequent cause of morbidity and mortality in premature infants. Parenchymal lung changes in BPD are relatively well-characterized and highly studied; however, there has been less emphasis placed on the role that airways disease plays in the pathophysiology of BPD. In preterm infants born between 22 and 32 weeks gestation, the conducting airways are fully formed but still immature and therefore susceptible to injury and further disruption of development. The arrest of maturation results in more compliant airways that are more susceptible to deformation and damage. Consequently, neonates with BPD are prone to developing airway pathology, particularly for patients who require intubation and positive-pressure ventilation. Airway pathology, which can be divided into large and small airways disease, results in increased respiratory morbidity in neonates with chronic lung disease of prematurity.

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.

Association of the Respiratory Severity Score with Bronchopulmonary Dysplasia-Associated Pulmonary Hypertension in Infants Born Extremely Preterm

Objective

To test the hypothesis that elevations in the respiratory severity score (RSS) are associated with increased risk of bronchopulmonary dysplasia-associated pulmonary hypertension (BPD-PH).

Study Design

Retrospective cohort study of infants born extremely preterm admitted to a BPD center between 2010-2018. Echocardiograms obtained ≥36 weeks' post-menstrual age (PMA) were independently adjudicated by two blinded cardiologists to determine the presence/absence of BPD-PH. Multivariable logistic regression estimated the association between RSS with BPD-PH.

Result

BPD-PH was observed in 68/223 (36%) of subjects. The median RSS at time of echocardiography was 3.04 (Range 0-18.3). A one-point increase in RSS was associated with BPD-PH, aOR 1.3 (95% CI 1.2-1.4), after adjustment for gestational age and PMA at time of echocardiography.

Conclusion

Elevations in the RSS were associated with a greater risk of BPD-PH. Prospective studies are needed to determine the validity and performance of RSS as a clinical susceptibility/risk biomarker for BPD-PH.