Severe bronchopulmonary dysplasia - incidence and predictive factors in a prospective, multicenter study in very preterm infants with respiratory distress syndrome

Early childhood respiratory morbidity according to gestational age at birth: A nationwide cohort study

BACKGROUND

Preterm birth survivors are at risk for short- and long-term respiratory morbidity. This includes increased rates of chronic obstructive pulmonary disease and infectious morbidity. Previous studies showed increased utilization of healthcare services throughout early childhood. However, only a few large-scale studies showed the effect on respiratory morbidity throughout the full spectrum of gestational age at birth. The aim of this study was to show the healthcare burden associated with prematurity, in a large nationwide cohort.

STUDY DESIGN

Data regarding gestational age at birth, month and year of birth, and infant sex were gathered for all 1,762,149 infants born in Israel between January 1, 2010, and December 31, 2019. Rates of hospitalization, length of hospitalization, and emergency department visits were calculated per 1000 live births and stratified by gestational age. Poisson regression was constructed to adjust for infant sex, year and month of birth.

RESULTS

Preterm birth occurred in 6.43 % of deliveries (n = 109,405). A negative association was found between gestational age at birth and respiratory morbidity. As gestational age at birth advances, rates of respiratory hospitalization decrease, and length of hospitalization shortens. This association continues even after full term is reached.

CONCLUSION

The short- and long-term effect of preterm birth poses a significant burden on healthcare systems globally, not only at birth or in infancy, but well into early childhood. These results are a call for action to stakeholders and professional organizations to increase efforts in preventing and treating preterm and early term labor.

A Comprehensive Compilation of Data on the Relationship Between Surfactant Protein-B (SFTPB) Polymorphisms and Susceptibility to Neonatal Respiratory Distress Syndrome

BACKGROUND

This study aims to explore the association between variations in the Surfactant Protein-B (SFTPB) gene and the risk of neonatal respiratory distress syndrome (NRDS).

METHODS

A comprehensive literature search was conducted across PubMed, Scopus, EMBASE, and CNKI databases up to February 10, 2024, to identify pertinent studies.

RESULTS

A total of seventeen studies examining the +1580 C/T polymorphism (2,058 cases and 2,596 controls) and five studies investigating the -18 A/C polymorphism (680 cases and 739 controls) were included in the analysis. The pooled data indicated that the +1580 C/T polymorphism confers a protective effect against NRDS in various populations and ethnic groups. Conversely, the -18 A/C polymorphism did not demonstrate a significant association either globally or among Asian neonates.

CONCLUSIONS

The +1580 C/T variant appears to be protective against NRDS, whereas the -18 A/C polymorphism shows minimal impact on the disease's progression.

Predictive value of serum MED1 and PGC-1α for bronchopulmonary dysplasia in preterm infants

OBJECTIVE

This study aimed to predict the bronchopulmonary dysplasia (BPD) in preterm infants with a gestational age(GA) < 32 weeks utilizing clinical data, serum mediator complex subunit 1 (MED1), and serum peroxisome proliferator-activated receptor gamma coactivator-1alpha (PGC-1α).

METHODS

This prospective observational study enrolled 70 preterm infants with GA < 32 weeks. The infants were categorized into two groups: non-BPD group(N = 35) and BPD group(N = 35), including 25 cases with mild BPD and 10 patients with moderate/severe subgroups. We performed multifactorial regression analysis to investigate the postnatal risk factors for BPD. Furthermore, we compared serum levels of biomarkers, including MED1 and PGC-1α, among infants with and without BPD at postnatal days 1, 7, 14, 28, and PMA 36 weeks. A logistic regression model was constructed to predict BPD's likelihood using clinical risk factors and serum biomarkers.

RESULTS

Serum levels of MED1 on the first postnatal day, PGC-1α on the 1st, 7th, and 28th days, and PMA at 36 weeks were significantly lower in the BPD group than in the non-BPD group (P < 0.05). Furthermore, the predictive model for BPD was created by combing serum levels of MED1 and PGC-1α on postnatal day 1 along with clinical risk factors such as frequent apnea, mechanical ventilation time > 7 d, and time to reach total enteral nutrition. Our predictive model had a high predictive accuracy(C statistics of 0.989) .

CONCLUSION

MED1and PGC-1α could potentially serve as valuable biomarkers, combined with clinical factors, to aid clinicians in the early diagnosis of BPD.

Long-term pulmonary outcomes of young adults born prematurely: a Polish prospective cohort study PREMATURITAS 20

BACKGROUND

The long-term consequences of prematurity are often not sufficiently recognized. To address this gap, a prospective cohort study, which is a continuation of the multicenter Polish study PREMATURITAS, was conducted, utilizing unique clinical data from 20 years ago.

OBJECTIVE

The main goal was to evaluate lung function, detect any structural abnormalities using lung ultrasound, and assess psychological well-being in young adults born between 24 and 34 weeks of gestational age (GA). Additionally, the study aimed to investigate potential associations between perinatal risk factors and abnormalities observed in pulmonary function tests (PFTs) during adulthood.

METHODS

The young survivors underwent a comprehensive set of PFTs, a lung ultrasound, along with the quality of life assessment. Information regarding the neonatal period and respiratory complications was obtained from the baseline data collected in the PREMATURITAS study.

RESULTS

A total of 52 young adults, with a mean age of 21.6 years, underwent PFTs. They were divided into two groups based on GA: 24-28 weeks (n = 12) and 29-34 weeks (n = 40). The subgroup born more prematurely had significantly higher lung clearance index (LCI), compared to the other subgroup (p = 0.013). LCI ≥ 6.99 was more frequently observed in the more premature group (50% vs. 12.5%, p = 0.005), those who did not receive prenatal steroids (p = 0.020), with a diagnosis of Respiratory Distress Syndrome (p = 0.034), those who received surfactant (p = 0.026), and mechanically ventilated ≥ 7 days (p = 0.005). Additionally, elevated LCI was associated with the diagnosis of asthma (p = 0.010).

CONCLUSIONS

The findings suggest pulmonary effects due to prematurity persist into adulthood and their insult on small airway function. Regular follow-up evaluations of young survivors born preterm should include assessments of PFTs. Specifically, the use of LCI can provide valuable insights into long-term pulmonary impairment.

Risk Prediction of Severe Bronchopulmonary Dysplasia (BPD) Using the Respiratory Severity Score (RSS) in Extremely Preterm Infants: A Retrospective Study From Saudi Arabia

Background Bronchopulmonary dysplasia (BPD) is a significant complication in extremely preterm infants. Therefore, early diagnosis of BPD is important for planning treatment strategies. In this study, we aimed to assess the predictive efficacy of the Respiratory Severity Score (RSS) in determining severe BPD or death outcomes in very preterm infants. Methodology This retrospective study included preterm infants born with a gestational age of ≤30 weeks. The inclusion criteria comprised individuals who were mechanically ventilated (<1 week) during the first four weeks of life. Any patients who died during the first seven days of life were excluded. RSS values were recorded on days 3, 14, 21, and 28 of life. Multivariate logistic regression was used to identify a correlation between RSS and patient outcomes. Results A total of 154 infants were included in the analysis, of whom 82 (53.24%) developed severe BPD and 38 (24.67%) died. RSS was higher in patients who either died or developed severe BPD compared to those who survived. The multivariate logistic regression analysis revealed that RSSs at postnatal day 14 (odds ratio (OR) = 3.970; 95% confidence interval (CI) = 1.114-14.147; p < 0.05), day 21 (OR = 6.201; 95% CI = 1.937-19.851; p < 0.05), and day 28 (OR = 8.925; 95% CI = 3.331-28.383; p < 0.05) was significantly associated with a higher risk of death or severe BPD. Conclusions The findings of the present study revealed that RSS can help predict the risk of severe BPD in very preterm infants.

Overview of Caffeine Effects on Human Health and Emerging Delivery Strategies

Caffeine is a naturally occurring alkaloid found in various plants. It acts as a stimulant, antioxidant, anti-inflammatory, and even an aid in pain management, and is found in several over-the-counter medications. This naturally derived bioactive compound is the best-known ingredient in coffee and other beverages, such as tea, soft drinks, and energy drinks, and is widely consumed worldwide. Therefore, it is extremely important to research the effects of this substance on the human body. With this in mind, caffeine and its derivatives have been extensively studied to evaluate its ability to prevent diseases and exert anti-aging and neuroprotective effects. This review is intended to provide an overview of caffeine's effects on cancer and cardiovascular, immunological, inflammatory, and neurological diseases, among others. The heavily researched area of caffeine in sports will also be discussed. Finally, recent advances in the development of novel nanocarrier-based formulations, to enhance the bioavailability of caffeine and its beneficial effects will be discussed.

Identification of genetic susceptibility in preterm newborns with bronchopulmonary dysplasia by whole-exome sequencing: BIVM gene may play a role

Bronchopulmonary dysplasia (BPD) is a common chronic respiratory disease in preterm infants caused by multifactorial etiology. Genetic factors are involved in the occurrence of BPD, but studies have found that candidate genes have poor reproducibility and are influenced by ethnic heterogeneity; therefore, more exploration is still needed. We performed whole-exon sequencing in 34 preterm infants with BPD and 32 non-BPD control neonates. The data were analyzed and interpreted by Fisher difference comparison, PLINK and eQTL association analysis, KEGG and GO enrichment analysis, STRING tool, Cytoscape software, ProtParam tool, HOPE online software, and GEOR2 analysis on NCBI GEO dataset. BPD has a highly heterogeneity in different populations, and we found 35 genes overlapped with previous whole-exon sequencing studies, such as APOB gene. Arterial and epithelial cell development and energy metabolism pathways affect BPD. In this study, 24 key genes were identified, and BIVM rs3825519 mutation leads to prolonged assisted ventilation in patients with BPD. A novel DDAH1 mutation site (NM_012137: exon1: c.89 T > G: p.L30R) was found in 9 BPD patients.

CONCLUSION

BIVM gene rs3825519 mutation may play a role in the pathogenesis of BPD by affecting cilia movement, and the DDAH1 and APOB genes mutations may have a pathogenic role in BPD.

WHAT IS KNOWN

• Genetic factors are involved in the occurrence of bronchopulmonary dysplasia. • The candidate genes have poor reproducibility and are influenced by ethnic heterogeneity, therefore, more exploration is still needed.

WHAT IS NEW

• We identified the role of susceptible SNPs in BPD in Shenzhen, China, and identified 24 key genes that influence the pathogenesis of BPD, and also found 35 genes overlapped with previous whole exon sequencing studies, such as APOB gene. • We found that BIVM and DDAH1 genes may play a pathogenic role in the pathogenesis of BPD.

Factors influencing extrauterine growth retardation in singleton-non-small for gestational age infants in China: A prospective multicenter study

BACKGROUND

The incidence of extrauterine growth retardation (EUGR) varies considerably in different countries due to the distinct definitions and inclusion criteria of individual studies. Most studies included small for gestational age (SGA) very preterm infants (VPIs), resulting in a higher incidence of EUGR. Experts have suggested the accurate definition of "EUGR" in SGA infants is not "true EUGR". The postnatal growth curve of multiple premature births also differs from that of singletons. As far as we know, there is no study about relationship between singleton-non-SGA preterm infants and EUGR.

OBJECTIVES

To analyze the factors influencing EUGR among VPIs who were singleton-non-SGA in China.

METHODS

A prospective-multicenter study was conducted in 28 hospitals distributed through China from September 2019 to December 2020. The clinical data on singleton-non-SGA among VPIs were divided into EUGR group (n = 692) and non-EUGR group (n = 912).

RESULTS

Compared to non-EUGR group, the mean gestational age (GA), mean birth weight (BW) and percentage of BW in Fenton curve in EUGR group were lower (P < 0.001 for all). The incidence of EUGR among distinct GA groups (classifications of GA < 28weeks, 28-28⁺⁶ weeks, 29-29⁺⁶ weeks, 30-30⁺⁶ weeks and 31-31⁺⁶ weeks) and distinct BW groups (classifications of BW<1000 g, 1000-1249 g, 1250-1499 g, 1500-1999g and 2000-2500 g) were statistically significant (P = 0.004 and P <.001). Logistic regression analysis indicated that later addition of human milk fortifier (HMF), later attainment of HMF sufficient fortification, later return to BW, more accumulative days of fasting, longer duration of parenteral nutrition, total duration of oxygen support and moderate/severe bronchopulmonary dysplasia (BPD) were risk factors for the development of EUGR in singleton-non-SGA VPIs (P < 0.001, P = 0.002, P < 0.001, P = 0.002, P = 0.017, P = 0.003 and P = 0.002, respectively). The use of full-course antenatal steroids, greater BW as a percentile of the Fenton curve, breastfeeding initiation and faster average velocity of weight growth effectively protected against EUGR (P = 0.008, P < 0.001, P < 0.001 and P < 0.001, respectively).

CONCLUSIONS

The overall incidence of EUGR was 43.1% among singleton-non-SGA VPIs in China. Raising the full-course antenatal steroids usage, reducing the incidence of moderate and severe BPD, attaching importance to the management of enteral nutrition in VPIs and increasing the weight growth velocity can reduce the incidence of EUGR.

Relationship of plasma MBP and 8-oxo-dG with brain damage in preterm

Preterm infants face a significant risk of brain injury in the perinatal period, as well as potential long-term neurodevelopmental disabilities. However, preterm children with brain injury lack specific clinical manifestations in the early days. Therefore, timely and accurate diagnosis of brain injury is of vital importance. This study was to explore the diagnostic efficiency of myelin basic protein (MBP) and 8-oxo-deoxyguanosine (8-oxo-dG) serum levels in brain injury of premature infants. A total of 75 preterm infants with gestational age between 28 and 32 weeks and birth weight higher than 1,000 g were prospectively included. MBP serum levels were significantly higher in premature infants with white matter injury (WMI). 8-oxo-dG serum levels were significantly increased in both WMI and periventricular–intraventricular hemorrhages (PIVH). MBP and 8-oxo-dG were significantly correlated. The area under the curve was 0.811 [95% confidence interval (CI) 0.667–0.955; p = 0.002] in MBP and 0.729 (95% CI 0.562–0.897; p = 0.020) in 8-oxo-dG. Therefore, the results showed that high MBP levels indicated a possibility of WMI in the premature brain during the early postnatal period, while high 8-oxo-dG levels were closely related to both WMI and PIVH, thus suggesting that MBP and 8-oxo-dG could be used as potential neuro-markers of preterm brain injury.

Cardiopulmonary Function Abnormalities in Cohort of Adults following Bronchopulmonary Dysplasia as Preterm Infants

OBJECTIVE

This study was aimed to describe the cardiopulmonary profiles of adult patients with bronchopulmonary dysplasia (BPD), comparing them to normative adult values.

STUDY DESIGN

This study presents a retrospective chart review of all BPD patients followed in the adult BPD clinic, identified from institutional and archive databases, born preterm at ≤33 weeks of estimated gestational age (EGA) between January 1980 and December 2000.

RESULTS

Forty-four patients with BPD (26.4 ± 2.7 weeks of EGA) were included. Average age at follow-up was 19 years. Majority (61.4%) of the patients had a diagnosis of asthma. Mean spirometry values were: first second of forced expiration (FEV1) 74.1%, forced vital capacity (FVC) 80.7%, and FEV1/FVC 82.5%. Echocardiography (ECHO) images were reviewed, left ventricular (LV) structure and performance did not differ between obstructive and nonobstructive pulmonary function test (PFT) groups, but values of LV longitudinal strain were 4.8% lower than expected normal for adults. Patients with obstructive PFT had additional decreased right ventricular (RV) function by ECHO.

CONCLUSION

BPD patients in this study were found to have a burden of cardiorespiratory alterations that persisted into adulthood, with RV performance abnormalities found among patients with obstructive PFT.

KEY POINTS

· BPD patients born at extremes of prematurity have cardiorespiratory alterations in adulthood.. · Among patients with obstructive lung function, subtle cardiac performance abnormalities were found.. · Future directions should include systematic follow-up of premature newborns with BPD..

Mechanism of lncRNA H19 in Regulating Pulmonary Injury in Hyperoxia-Induced Bronchopulmonary Dysplasia Newborn Mice

OBJECTIVE

Bronchopulmonary dysplasia (BPD) is a pulmonary injury related to inflammation and is a major cause of premature infant death. Long noncoding RNAs (lncRNAs) are important regulators in pulmonary injury and inflammation. We investigated the molecular mechanism of lncRNA H19 in pulmonary injury and inflammation in hyperoxia (Hyp)-induced BPD mice.

STUDY DESIGN

The BPD newborn mouse model was established and intervened with H19 to evaluate the pathologic conditions and radial alveolar count (RAC) in lung tissues of mice in the room air (RA) and Hyp group on the 4th, 7th, and 14th days after birth. The levels of BPD-related biomarkers vascular endothelial growth factor (VEGF), transforming growth factor β1 (TGF-β1), and surfactant protein C (SPC) in lung tissues were detected on the 14th day after birth. The expression of and relationships among H19 and miR-17, miR-17, and STAT3 were detected and verified. Levels of interleukin (IL)-6, IL-1β, p-STAT3, and STAT3 levels in mouse lung tissues were detected on the 14th day after birth.

RESULTS

Hyp-induced mice showed increased alveolar diameter, septum, and hyperemia and inflammatory cell infiltration, upregulated H19, decreased overall number and significantly reduced RAC on the 7th and 14th days after birth, which were reversed in the si-H19-treated mice. VEGF was upregulated and TGF-β1 and SPC was decreased in si-H19-treated mice. Moreover, H19 competitively bound to miR-17 to upregulate STAT3. IL-6 and IL-1β expressions and p-STAT3 and STAT3 levels were downregulated after inhibition of H19.

CONCLUSION

Downregulated lncRNA H19 relieved pulmonary injury via targeting miR-17 to downregulate STAT3 and reduced inflammatory response caused by p-STAT3 in BPD newborn mice.

KEY POINTS

· lncRNA H19 was highly expressed in Hyp-induced BPD newborn mice.. · si-H19 relieved pulmonary injury in Hyp-induced BPD newborn mice.. · si-H19 upregulated miR-17 and downregulated STAT3 expression..

Caffeine and bronchopulmonary dysplasia: Clinical benefits and the mechanisms involved

Bronchopulmonary dysplasia (BPD) is a chronic respiratory disease that occurs during the neonatal period and is commonly associated with prematurity. This condition results in a severe economic burden on society and the families involved. Caffeine is used not only for the treatment of apnea in prematurity, but also for the prevention of BPD. There are multiple clinical benefits of caffeine treatment, including improved extubation success, a reduced duration of mechanical ventilation, improved lung function, and a reduction of patent ductus arteriosus requiring treatment. These clinical benefits of caffeine for the treatment of BPD are supported by both clinical trials and evidence from animal models. However, the mechanism by which caffeine protects against BPD remains unclear. Here, we review the clinical value of caffeine in the prevention of BPD and its potential mechanisms of action, including anti-inflammatory, antioxidant, antifibrotic, and antiapoptotic properties, the regulation of angiogenesis, and diuretic effects. Our aim is to provide a new theoretical basis for the clinical treatment of BPD.

Efficacy and safety of intratracheal administration of budesonide combined with pulmonary surfactant in preventing bronchopulmonary dysplasia: a prospective randomized controlled trial

OBJECTIVES

To study the efficacy and safety of early intratracheal administration of budesonide combined with pulmonary surfactant (PS) in preventing bronchopulmonary dysplasia (BPD).

METHODS

A prospective randomized controlled trial was designed. A total of 122 infants with a high risk of BPD who were admitted to the neonatal intensive care unit of the Third Affiliated Hospital of Zhengzhou University from January to July 2021 were enrolled. The infants were randomly divided into a conventional treatment group with 62 infants (treated with PS alone at an initial dose of 200 mg/kg, followed by a dose of 100 mg/kg according to the condition of the infant) and an observation group with 60 infants (treated with PS at the same dose as the conventional treatment group, with the addition of budesonide 0.25 mg/kg for intratracheal instillation at each time of PS application). The two groups were compared in terms of the times of PS use, ventilator parameters at different time points, oxygen inhalation, incidence rate and severity of BPD, incidence rate of complications, and tidal breathing pulmonary function at the corrected gestational age of 40 weeks.

RESULTS

Compared with the conventional treatment group, the observation group had a significantly lower proportion of infants using PS for two or three times (P<0.05). Compared with the conventional treatment group, the observation group had a significantly lower fraction of inspired oxygen at 24 and 48 hours and 3, 7, and 21 days after administration, significantly shorter durations of invasive ventilation, noninvasive ventilation, ventilator application, and oxygen therapy, a significantly lower incidence rate of BPD, and a significantly lower severity of BPD (P<0.05). There was no significant difference in the incidence rate of glucocorticoid-related complications between the two groups (P>0.05).

CONCLUSIONS

Compared with PS use alone in preterm infants with a high risk of BPD, budesonide combined with PS can reduce repeated use of PS, lower ventilator parameters, shorten the duration of respiratory support, and reduce the incidence rate and severity of BPD, without increasing the incidence rate of glucocorticoid-related complications.

Lung ultrasound predicts the development of bronchopulmonary dysplasia: a prospective observational diagnostic accuracy study

This study aimed to evaluate the predictive ability of lung ultrasound (LU) in the development of bronchopulmonary dysplasia (BPD) in very low birth weight (VLBW) infants. A total of 130 VLBW infants with gestational age < 32 weeks were included; LU was performed at days 1, 2, 3, 6, 9, 12, and 15 postnatally. We calculated the LU score by 12-region, 10-region, and 6-region protocols. The incidence of BPD according to the National Institutes of Health (NIH) 2001 definition and 2019 criteria was 38.5% and 64.6%, respectively. By 12-region and 10-region protocols, LU predicted BPD from the 9^th to 15^th days of life (DOLs) regardless of the criteria used, with an area under the curve (AUC) ranging from 0.826 (95% confidence interval (CI): 0.750-0.887) to 0.877 (95% CI: 0.807-0.928). According to the 2019 BPD definition, the LU score incorporated gestational age, and invasive mechanical ventilation >6 days predicted BPD on the 6^th DOL with an AUC of 0.862 (95% CI: 0.790-0.916). The 6-region protocol had significantly smaller AUC values on the 6^th and 9^th DOLs than the other two protocols.Conclusion: The 12-region and 10-region LU scoring protocols are superior to the 6-region protocol in the prediction of BPD. LU can predict the development of BPD from the 9^th to 15^th DOLs. With the addition of clinical variables, the earliest prediction time was the 6^th DOL. What is Known: • Bronchopulmonary dysplasia is the most common and adverse complication of prematurity. Recent four studies found that lung ultrasound score or findings predicted the development of bronchopulmonary dysplasia. What is New: • We present analysis by classical 6-region and the other two lung ultrasound score (10-region and 12-region) which include an assessment of the posterior lung to allow to understand what is the best score to be used. In addition, we explore whether LU-incorporated clinical variables could improve the predictive value for BPD.

VitA or VitD ameliorates bronchopulmonary dysplasia by regulating the balance between M1 and M2 macrophages

PURPOSE

To investigate the therapeutic effects of vitamin A (VitA) or vitamin D (VitD) against bronchopulmonary dysplasia (BPD) and the underlying mechanism from the perspective of macrophage polarization.

METHODS

A BPD model was established on rats. Hematoxylin and eosin staining was used to evaluate the pathological state of lung tissues. The expression of CD68 was determined by immunohistochemistry assay. The infiltration of M1 and M2 macrophages was marked by immunofluorescence. The expression levels of tumor necrosis factor (TNF)-α, interleukin (IL)-10, nitric oxide synthase (NOS), and arginase-1 (Arg-1) were evaluated by quantitative reverse transcription polymerase chain reaction assay, and the ratio of M1/M2 in the bronchoalveolar lavage fluid was determined by flow cytometry.

RESULTS

Disordered alveolar structure in the lung tissue, thickened alveolar septa, and infiltration of inflammatory cells around the alveolar cavity and pulmonary septa were observed in lipopolysaccharide (LPS)-treated rats. On day 21 post-natal (PN21), the pathological state was aggravated, alveolar simplification was observed, and the expression level of CD68 in the lung tissues was significantly elevated, and these results were dramatically alleviated in the VitA, VitD, and VitA+VitD groups. However, no significant synergistic effect was observed between VitA+VitD and VitA or VitD groups. After the administration with VitA or VitD, IL-10 and Arg-1 were up-regulated on PN10. TNF-α and NOS were up-regulated on PN21. The ratio of macrophage polarization and M2 macrophages increased considerably after the stimulation with LPS, and this result was significantly reversed by VitA or VitD. A significant difference was observed on the effect of different dosages of VitA or VitD on macrophage polarization, among which moderate dosages of VitA or VitD exerted the most significant influence on macrophage polarization.

CONCLUSION

The BPD-linked pulmonary injury stimulated by LPS can be ameliorated by the introduction of VitA or VitD.

Delivery room resuscitation and short-term outcomes of extremely preterm and extremely low birth weight infants: a multicenter survey in North China

Background:

Delivery room resuscitation assists preterm infants, especially extremely preterm infants (EPI) and extremely low birth weight infants (ELBWI), in breathing support, while it potentially exerts a negative impact on the lungs and outcomes of preterm infants. This study aimed to assess delivery room resuscitation and discharge outcomes of EPI and ELBWI in China.

Methods:

The clinical data of EPI (gestational age [GA] <28 weeks) and ELBWI (birth weight [BW] <1000 g), admitted within 72 h of birth in 33 neonatal intensive care units from five provinces and cities in North China between 2017 and 2018, were analyzed. The primary outcomes were delivery room resuscitation and risk factors for delivery room intubation (DRI). The secondary outcomes were survival rates, incidence of bronchopulmonary dysplasia (BPD), and risk factors for BPD.

Results:

A cohort of 952 preterm infants were enrolled. The incidence of DRI, chest compressions, and administration of epinephrine was 55.9% (532/952), 12.5% (119/952), and 7.0% (67/952), respectively. Multivariate analysis revealed that the risk factors for DRI were GA <28 weeks (odds ratio [OR], 3.147; 95% confidence interval [CI], 2.082–4.755), BW <1000 g (OR, 2.240; 95% CI, 1.606–3.125), and antepartum infection (OR, 1.429; 95% CI, 1.044–1.956). The survival rate was 65.9% (627/952) and was dependent on GA. The rate of BPD was 29.3% (181/627). Multivariate analysis showed that the risk factors for BPD were male (OR, 1.603; 95% CI, 1.061–2.424), DRI (OR, 2.094; 95% CI, 1.328–3.303), respiratory distress syndrome exposed to ≥2 doses of pulmonary surfactants (PS; OR, 2.700; 95% CI, 1.679–4.343), and mechanical ventilation ≥7 days (OR, 4.358; 95% CI, 2.777–6.837). However, a larger BW (OR, 0.998; 95% CI, 0.996–0.999), antenatal steroid (OR, 0.577; 95% CI, 0.379–0.880), and PS use in the delivery room (OR, 0.273; 95% CI, 0.160–0.467) were preventive factors for BPD (all P < 0.05).

Conclusion:

Improving delivery room resuscitation and management of respiratory complications are imperative during early management of the health of EPI and ELBWI.

Ciclesonide activates glucocorticoid signaling in neonatal rat lung but does not trigger adverse effects in the cortex and cerebellum

Synthetic glucocorticoids (sGCs) such as dexamethasone (DEX), while used to mitigate inflammation and disease progression in premature infants with severe bronchopulmonary dysplasia (BPD), are also associated with significant adverse neurologic effects such as reductions in myelination and abnormalities in neuroanatomical development. Ciclesonide (CIC) is a sGC prodrug approved for asthma treatment that exhibits limited systemic side effects. Carboxylesterases enriched in the lower airways convert CIC to the glucocorticoid receptor (GR) agonist des-CIC. We therefore examined whether CIC would likewise activate GR in neonatal lung but have limited adverse extra-pulmonary effects, particularly in the developing brain. Neonatal rats were administered subcutaneous injections of CIC, DEX or vehicle from postnatal days 1-5 (PND1-PND5). Systemic effects linked to DEX exposure, including reduced body and brain weight, were not observed in CIC treated neonates. Furthermore, CIC did not trigger the long-lasting reduction in myelin basic protein expression in the cerebral cortex nor cerebellar size caused by neonatal DEX exposure. Conversely, DEX and CIC were both effective at inducing the expression of select GR target genes in neonatal lung, including those implicated in lung-protective and anti-inflammatory effects. Thus, CIC is a promising, novel candidate drug to treat or prevent BPD in neonates given its activation of GR in neonatal lung and limited adverse neurodevelopmental effects. Furthermore, since sGCs such as DEX administered to pregnant women in pre-term labor can adversely affect fetal brain development, the neurological-sparing properties of CIC, make it an attractive alternative for DEX to treat pregnant women severely ill with respiratory illness, such as with asthma exacerbations or COVID-19 infections.

Does surfactant nebulization prevent early intubation in preterm infants? A protocol for a systematic review and meta-analysis

BACKGROUND

Respiratory distress syndrome (RDS) is the most common cause of respiratory failure in preterm infants. Treatment consists of respiratory support and exogenous surfactant administration. Commonly, surfactant is administered intratracheally. However, this requires airway instrumentation and subsequent fluid instillation which may be harmful. Surfactant nebulization (SN) may offer a safe and effective alternative for surfactant administration, but the clinical efficacy is not yet established. Thus, this systematic review and meta-analysis of randomized controlled trials will summarize the available evidence to determine the effectiveness and safety of SN for the prevention of intubation and subsequent mechanical ventilation at 72 h after birth.

METHODS

A systematic literature search in Medline, Embase, and The Cochrane Library will be performed, and all randomized controlled trials (RCTs) and quasi-RCTs from published articles, presentations, and trial registries will be included in this meta-analysis. Titles and abstracts of all records identified in the search will be screened by two reviewers independently. Data on preterm infants (≤ 37 weeks) receiving nebulized surfactant in the first 72 h after birth for the treatment or prevention of RDS will be evaluated. Primary outcome is the intubation rate by 72 h after birth, and secondary outcomes include peridosing safety effects as well as major neonatal morbidities. Risk of bias will be assessed using the revised Cochrane ROB tool, and subgroup analyses will be performed to evaluate potential confounding factors. Publication bias will be assessed by examining a funnel plot. The meta-analysis will be performed using a fixed-effects model.

DISCUSSION

This review will provide an evidence-based tool for information about surfactant nebulization, illustrating the current knowledge and hopefully revealing potential novel avenues for researchers and clinicians alike.

SYSTEMATIC REVIEW REGISTRATION

This review is registered with the publicly available resource PROSPERO ( CRD42020175625 ).

Development and Validation of a Nomogram for Predicting Bronchopulmonary Dysplasia in Very-Low-Birth-Weight Infants

Background: Bronchopulmonary dysplasia is a common pulmonary disease in newborns and is one of the main causes of death. The aim of this study was to build a new simple-to-use nomogram to screen high-risk populations. Methods: In this single-center retrospective study performed from January 2017 to December 2020, we reviewed data on very-low-birth-weight infants whose gestational ages were below 32 weeks. LASSO regression was used to select variables for the risk model. Then, we used multivariable logistic regression to build the prediction model incorporating these selected features. Discrimination was assessed by the C-index, and and calibration of the model was assessed by and calibration curve and the Hosmer-Lemeshow test. Results: The LASSO regression identified gestational age, duration of ventilation and serum NT-proBNP in the 1st week as significant predictors of BPD. The nomogram-illustrated model showed good discrimination and calibration. The C-index was 0.853 (95% CI: 0.851-0.854) in the training set and 0.855 (95% CI: 0.77-0.94) in the validation set. The calibration curve and Hosmer-Lemeshow test results showed good calibration between the predictions of the nomogram and the actual observations. Conclusion: We demonstrated a simple-to-use nomogram for predicting BPD in the early stage. It may help clinicians recognize high-risk populations.

Lung disease and pulmonary hypertension in the premature infant

The premature infant is born into the world unprepared to naturally thrive in a foreign environment. Lung development entails immense growth, structural remodeling and differentiation of specialized cells during the normal term perinatal and postnatal periods. Thus, the premature infant presents with a lung deficient for appropriate respiration. Disruption of lung development seen in bronchopulmonary dysplasia (BPD) and chronic lung disease (CLD) results in not only impaired airway growth but also a deficiency in the accompanying vasculature including the capillary system required for gas exchange. Deficient vascular area can lead to elevated pulmonary vascular resistance and the development of pulmonary hypertension (PH). Unlike PH seen in children and adults with pulmonary arterial hypertension (PAH), treatment with conventional pulmonary vasodilators can be limited in developmental lung disease-associated PH because there are fewer blood vessels to dilate. In this brief review, we highlight some of the knowledge on PH in the premature infant presented at the Proceedings of the 22^nd Annual Update on Pediatric and Congenital Cardiovascular Disease.

Physiological Basis of Neonatal Aerodigestive Difficulties in Chronic Lung Disease

In the United States, preterm birth rates have steadily increased since 2014. Despite the recent advances in neonatal-perinatal care, more than 40% of very low-birth-weight infants develop chronic lung disease (CLD) and almost 25% have feeding difficulties resulting in delayed achievement of full oral feeds and longer hospital stay. Establishment of full oral feeds, a major challenge for preterm infants, becomes magnified among those on respiratory support and/or with CLD. The strategies to minimize aerodigestive disorders include supporting nonnutritive sucking, developing infant-directed feeding protocols, sensory oromotor stimulation, and early introduction of oral feeds.

Early prediction of moderate to severe bronchopulmonary dysplasia in extremely premature infants

BACKGROUND

Bronchopulmonary Dysplasia (BPD) is the commonest morbidity in extremely preterm infants (PTIs). Risk factors for BPD have been described in the era before the widespread availability of non-invasive ventilation (NIV) in the delivery room (DR). The objective of this study is to identify risk factors for Moderate/Severe BPD in an era of widespread availability of NIV in the DR.

METHODS

Detailed antenatal and postnatal data were abstracted for PTIs, 23^0/7-27^6/7 weeks GA. Multivariate logistic regression and classification and regression tree analyses (CART) identified predictors for the primary outcome of Moderate/Severe BPD.

RESULTS

Of 263 eligible infants, 59% had Moderate/Severe BPD. Moderate/Severe BPD was significantly associated with birthweight, gender, DR intubation and surfactant compared to No/Mild BPD. Of infants not intubated in the DR, 40% with No/Mild BPD and 80% with Moderate/Severe BPD received intubation by 48 hours (p < 0.05). Infants with Moderate/Severe BPD received longer duration of oxygen and mechanical (MV). On logistic regression, birthweight, gender, oxygen concentration, cumulative duration of oxygen and MV, surfactant, and blood transfusions predicted Moderate/Severe BPD. Both CART analysis and logistic regression showed duration of oxygen and MV to be the most important predictors for Moderate/Severe BPD.

CONCLUSIONS

In an era of increasing availability of NIV in the DR, lower birthweight, male gender, surfactant treatment, blood transfusions and respiratory support in the first 2-3 weeks after birth predict Moderate/Severe BPD with high sensitivity and specificity. The majority of these infants received intubation within 48 hours of birth (97%). These data suggest that early failures of NIV represent opportunities for improvement of NIV techniques and of non-invasive surfactant to avoid intubation in the first 48 hours. Furthermore, these risk factors may allow earlier identification of infants most likely to benefit from interventions to prevent or decrease severity of BPD.

Genetic Polymorphisms of LPCAT1, CHPT1 and PCYT1B and Risk of Neonatal Respiratory Distress Syndrome among a Chinese Han Population

BACKGROUND

The study of genetic polymorphisms of surfactant-lipids related genes can help to understand individual variability in the susceptibility to development of pulmonary pathologies. The purpose of this study was to evaluate the association of polymorphisms of surfactant-lipids related genes (LPCAT1, CHPT1 and PCYT1B) with the risk/severity of respiratory distress syndrome (RDS) in preterm neonates among the Chinese Han population in Southern China.

METHODS

Four hundred and forty-six preterm neonates were enrolled in a case-control study. Six polymorphisms of 3 genes were analyzed by PCR amplification of genomic DNA and genotyping was performed using an improved multiplex ligation detection reaction (iMLDR) technique based on LDR.

RESULTS

The GG genotype and G allele of LPCAT1-rs9728 were found less frequently in the RDS group than in the controls (11.5% vs. 22.0% and 38.3% vs. 48.2%, respectively) (p < 0.05).

CONCLUSION

This report is the first study to evaluate a direct genetic association between polymorphisms of LPCAT1 and RDS development in Chinese Han preterm infants. Our study raises the possibility that a genetic variation of LPCAT1 could be implicated in the pathophysiology of RDS in preterm neonates. GG genotype and G allele of rs9728 are protective factors for the development of RDS in preterm infants.

An Innovative Model of Bronchopulmonary Dysplasia in Premature Infants

Bronchopulmonary dysplasia (BPD) is one of the common chronic lung diseases (CLD) of premature infants, which causes unpredictable consequences to the family and society. Therefore, the pathogenesis and prevention methods of BPD are the focus of current research, and the establishment of an effective and appropriate animal model of BPD in premature infants is the key to the research. In this study, premature rats were exposed to hyperoxia environment. Compared with the air group, the body weight and alveolar radiation count of the hyperoxia group decreased significantly, but there was no significant difference in body length. HE staining was used to observe the pathological changes of BPD in the lung tissue. The above results proved that under the hyperoxia condition, the BPD animal model of premature infants was successfully established, which provided a new choice for the future research of BPD.

Predictors of Early Extubation after Patent Ductus Arteriosus Ligation among Infants Born Extremely Preterm Dependent on Mechanical Ventilation

We conducted a retrospective study of 166 ventilator-dependent neonates born extremely preterm in whom patent ductus arteriosus was surgically ligated and evaluated the association of preoperative characteristics and time-to-successful postoperative extubation. Larger patent ductus arteriosus diameter ([>2.5 mm], adjusted hazard ratio 0.51, 95% CI 0.36-0.72) and left-ventricular dilatation (z score ≥2, adjusted hazard ratio 0.61, 95% CI 0.42-0.87) were associated with earlier extubation.

Timing of Referral to Early Intervention Services in Infants With Severe Bronchopulmonary Dysplasia

This study is a secondary analysis of an observational prospective case series of 50 infants with severe bronchopulmonary dysplasia that describes patient factors associated with the time between initial hospital discharge and referral to early intervention (EI) services. It also evaluates associations between (1) timing of EI referral and reception of EI services and (2) early referral to EI and developmental outcomes at 18 to 36 months corrected age. The results demonstrated that a referral from a neonatologist versus a pediatrician was associated with fewer days between discharge and EI referral. Earlier EI referrals were associated with a shorter time to intake evaluation and service initiation. The Bayley-III (Bayley Scales of Infant and Toddler Development, 3rd Edition) scores at 24 months corrected age (n = 28) were not associated with timing of EI referral. In conclusion, an early referral to EI promoted earlier evaluation and initiation of EI services and should be standard for high-risk infants.

Long-term outcomes of preterm infants treated with less invasive surfactant technique (LISA)

OBJECTIVE

The aim of this study is to compare the clinical outcomes at 24 months postmenstrual age of two populations receiving beractant replacement therapy using less invasive surfactant administration (LISA) versus intubation, administration of surfactant, and early extubation (INSURE). Hospital admission requirements, psychomotor development, and respiratory and neurological outcomes were studied.

STUDY DESIGN

This was a single-center, retrospective, and descriptive study with a sample of 60 patients (30 for each group) on nasal continuous positive airway pressure during the first 3 days of life, requiring surfactant administration.

RESULTS

We found no significant differences between both groups on psychomotor development and respiratory and neurological outcomes.

CONCLUSION

Compared to INSURE technique, the administration of surfactant by LISA is feasible and safe and reduces invasive mechanical ventilation exposure with no differences in the follow-up neurodevelopmental and respiratory outcomes at 24 postmenstrual age.

The Impact of Nonequilibrium Conditions in Lung Surfactant: Structure and Composition Gradients in Multilamellar Films

The lipid-protein mixture that covers the lung alveoli, lung surfactant, ensures mechanical robustness and controls gas transport during breathing. Lung surfactant is located at an interface between water-rich tissue and humid, but not fully saturated, air. The resulting humidity difference places the lung surfactant film out of thermodynamic equilibrium, which triggers the buildup of a water gradient. Here, we present a millifluidic method to assemble multilamellar interfacial films from vesicular dispersions of a clinical lung surfactant extract used in replacement therapy. Using small-angle X-ray scattering, infrared, Raman, and optical microscopies, we show that the interfacial film consists of several coexisting lamellar phases displaying a substantial variation in water swelling. This complex phase behavior contrasts to observations made under equilibrium conditions. We demonstrate that this disparity stems from additional lipid and protein gradients originating from differences in their transport properties. Supplementing the extract with cholesterol, to levels similar to the endogenous lung surfactant, dispels this complexity. We observed a homogeneous multilayer structure consisting of a single lamellar phase exhibiting negligible variations in swelling in the water gradient. Our results demonstrate the necessity of considering nonequilibrium thermodynamic conditions to study the structure of lung surfactant multilayer films, which is not accessible in bulk or monolayer studies. Our reconstitution methodology also opens avenues for lung surfactant pharmaceuticals and the understanding of composition, structure, and property relationships at biological air-liquid interfaces.

Pulmonary endothelial cells exhibit sexual dimorphism in their response to hyperoxia

Abnormal pulmonary vascular development is a critical factor in the pathogenesis of bronchopulmonary dysplasia (BPD). Despite the well-established sex-specific differences in the incidence of BPD, the molecular mechanism(s) behind these are not completely understood. Exposure to a high concentration of oxygen (hyperoxia) contributes to BPD and creates a profibrotic environment in the lung. Our objective was to elucidate the sex-specific differences in neonatal human pulmonary microvascular endothelial cells (HPMECs) in normoxic and hyperoxic conditions, including the propensity for endothelial-to-mesenchymal transition. HPMECs (18- to 24-wk gestation donors, 6 male donors and 5 female donors) were subjected to hyperoxia (95% O₂ and 5% CO₂) or normoxia (air and 5% CO₂) up to 72 h. We assessed cell migration and angiogenesis at baseline. Cell proliferation, viability, and expression of endothelial (CD31) and fibroblast markers (α-smooth muscle actin) were measured upon exposure to hyperoxia. Female HPMECs had significantly higher cell migration when assessed by the wound healing assay (40.99 ± 4.4%) compared with male HPMECs (14.76 ± 3.7%) and showed greater sprouting (1710 ± 962 μm in female cells vs. 789 ± 324 in male cells) compared with male endothelial cells in normoxia. Hyperoxia exposure decreased cell viability (by 9.8% at 48 h and 11.7% at 72 h) and proliferation (by 26.7% at 72 h) markedly in male HPMECs, whereas viability was sustained in female endothelial cells. There was greater expression of α-smooth muscle actin (2.5-fold) and decreased expression (5-fold) of CD31 in male HPMECs upon exposure to hyperoxia. The results indicate that cellular sex affects response in HPMECs in normoxia and hyperoxia. NEW & NOTEWORTHY Cellular sex affects response in human neonatal pulmonary microvascular endothelial cells in normoxia and hyperoxia. Under normoxic conditions, female human neonatal pulmonary microvascular endothelial cells display greater migration and angiogenic sprouting compared with male endothelial cells. Compared with female endothelial cells, hyperoxia exposure decreased cell viability and proliferation and increased α-smooth muscle actin and decreased CD31 expression in male endothelial cells, indicating an increased endothelial-mesenchymal transition.

Does the sex of the preterm baby affect respiratory outcomes?

Being born very preterm is associated with later deficits in lung function and an increased rate of respiratory symptoms compared with term-born children. The rates of early respiratory infections are higher in very preterm-born subjects, which may independently lead to deficits in lung function in later life. As with very preterm-born children, deficits in lung function, increased respiratory symptoms and an increased risk of respiratory infections in early life are observed in late -preterm-born children. However, the rates of respiratory symptoms are lower compared with very preterm-born children. There is some evidence to suggest that respiratory outcomes may be improving over time, although not all the evidence suggests improvements. Male sex appears to increase the risk for later adverse respiratory illness. Although not all studies report that males have worse long-term respiratory outcomes than females. It is essential that preterm-born infants are followed up into childhood and beyond, and that appropriate treatment for any lung function deficits and respiratory symptoms is prescribed if necessary. If these very preterm-born infants progress to develop chronic obstructive airway disease in later life then the impact, not only on the individuals, but also the economic impact on healthcare services, is immense.

Educational aims

To report the effect of the sex of the preterm baby on respiratory outcomes.To explore the short- and long-term respiratory outcomes of preterm birth.