Correlation of Early Nutritional Supply and Development of Bronchopulmonary Dysplasia in Preterm Infants <1,000 g

Multidisciplinary evidence-based tools for improving consistency of care and neonatal nutrition

BACKGROUND

Extrauterine growth restriction from inadequate nutrition remains a significant morbidity in very low birth weight infants. Participants in the California Perinatal Quality Care Collaborative Quality Improvement Collaborative, Grow, Babies, Grow! developed or refined tools to improve nutrition and reduce practice variation.

METHOD

Five Neonatal Intensive Care Units describe the development and implementation of nutrition tools. Tools include Parenteral Nutrition Guidelines, Automated Feeding Protocol, electronic medical record Order Set, Nutrition Time-Out Rounding Tool, and a Discharge Nutrition Recommendations. 15 of 22 participant sites completed a survey regarding tool value and implementation.

RESULTS

Reduced growth failure at discharge was observed in four of five NICUs, 11-32% improvement. Tools assisted with earlier TPN initiation (8 h) and reaching full feeds (2-5 days). TPN support decreased by 5 days. 80% of survey respondents rated the tools as valuable.

CONCLUSION

Evidence and consensus-based nutrition tools help promote standardization, leading to improved and sustainable outcomes.

Breast-feeding as protective factor against bronchopulmonary dysplasia in preterm infants

Breast-feeding is associated with fewer comorbidities in very-low-birth-weight (VLBW) preterm infants. Bronchopulmonary dysplasia (BPD) of VLBW infants is a multifactorial pathology in which nutritional aspects may be of special importance. The aim of this study is to determine, in a cohort of VLBW infants, whether breast milk nutrition is associated with a reduced prevalence and severity of BPD. A retrospective study was conducted to record the intake of mother's own milk (MOM), pasteurised donor human milk or preterm formula milk in the first 2 weeks of postnatal life of 566 VLBW newborns at our hospital during the period January 2008-December 2021. After applying the relevant exclusion criteria, data for 489 VLBW infants were analysed; 195 developed some degree of BPD. Moderate or severe BPD is associated with less weight gain. Moreover, the preferential ingestion of breast milk in the first and second postnatal weeks had effects associated with lower OR for BPD, which were statistically demonstrable for mild (OR 0·16; 95 % CI 0·03, 0·71) and severe (OR 0·08; 95 % CI 0·009, 0·91) BPD. Breast-feeding during the first weeks of postnatal life is associated with a reduced prevalence of BPD, which is frequently associated with less weight gain as a result of greater respiratory effort with greater energy expenditure.

The role of nutritional interventions in the prevention and treatment of chronic lung disease of prematurity

Chronic lung disease of prematurity or bronchopulmonary dysplasia (BPD) is a common complication of preterm birth. Nutrition may affect incidence and severity of BPD. In this context, the Section on Nutrition, Gastroenterology and Metabolism, the Pulmonary Section of the European Society for Paediatric Research (ESPR) and SPR have joined forces to review the current knowledge on nutritional issues related to BPD. The aim of this narrative review is to discuss the clinical implications for nutritional practice. Nutrient deficiencies may influence pathogenesis of BPD. Adequate nutrition and growth can play a crucial role in the prevention of and recovery from BPD. Optimal nutrition strategy is an important principle, especially in the early postnatal period. As optimal energy intake in infants at risk of BPD or with evolving BPD is not yet defined, further research with well-designed studies on nutritional strategies for preterm infants with BPD is urgently needed. IMPACT: Based on current evidence it seems reasonable to recommend that BPD diagnosed infants should receive an energy supply ranging from 120 to 150 Kcal/kg/d. Exclusive MOM feed with adequate fortification should be encouraged as this is associated with a significant reduction in the risk of BPD. Suboptimal nutritional delivery is often seen in preterm infants with BPD compared to controls.

AMPK/MTOR/TP53 Signaling Pathway Regulation by Calcitonin Gene-Related Peptide Reduces Oxygen-Induced Lung Damage in Neonatal Rats through Autophagy Promotion

Our previous studies indicated that calcitonin gene-related peptide (CGRP) alleviates hyperoxia-induced lung injury and suggested the possible involvement of autophagy in this process. Herein, we aimed to further explore the potential involvement of tumor protein p53 (TP53) and autophagy in the mode of action of CGRP against hyperoxia-induced lung injury in vitro and in vivo. The study conducted tests on type II alveolar epithelial cells (AECII) and rats that were subjected to hyperoxia treatment or combined treatment of hyperoxia with CGRP, CGRP inhibitor, rapamycin (an autophagy agonist), 3-methyladenine (3-MA, an autophagy inhibitor), TP53 silencing/inhibitor (pifithrin-α), or expression vector/activator (PRIMA-1 (2,2-bis(hydroxymethyl)-3-quinuclidinone)) and their corresponding controls. We found that oxidative stress, apoptosis, and autophagy were all increased by hyperoxia treatment in vitro. However, treating AECII cells with CGRP reversed hyperoxia-induced oxidative stress and apoptosis but further promoted autophagy. In addition, the combined treatment with rapamycin or TP53 silencing with CGRP promoted the effect of CGRP, while contrary results were obtained with combined therapy with 3-MA or TP53 overexpression. In vivo, the number of hyperoxia-induced autophagosomes was promoted in the lung tissue of neonatal rats. Furthermore, hyperoxia increased the expression levels of AMP-activated protein kinase (AMPK) alpha 1 (also known as protein kinase AMP-activated catalytic subunit alpha 1 (PRKAA1)) but inhibited TP53 and mechanistic target of rapamycin (MTOR); these expression trends were regulated by CGRP treatment. In conclusion, we showed that CGRP can attenuate hyperoxia-induced lung injury in neonatal rats by enhancing autophagy and regulating the TP53/AMPK/MTOR crosstalk axis.

Microbial signatures in amniotic fluid at preterm birth and association with bronchopulmonary dysplasia

BACKGROUND

Microbiome dysbiosis can have long-lasting effects on our health and induce the development of various diseases. Bronchopulmonary dysplasia (BPD) is a multifactorial disease with pre- and postnatal origins including intra-amniotic infection as main risk factor. Recently, postnatal pathologic lung microbiota colonization was associated with BPD. The objectives of this prospective observational cohort study were to describe differences in bacterial signatures in the amniotic fluid (AF) of intact pregnancies without clinical signs or risk of preterm delivery and AF samples obtained during preterm deliveries and their variations between different BPD disease severity stages.

METHODS

AF samples were collected under sterile conditions during fetal intervention from intact pregnancies (n = 17) or immediately before preterm delivery < 32 weeks (n = 126). Metabarcoding based approaches were used for the molecular assessment of bacterial 16S rRNA genes to describe bacterial community structure.

RESULTS

The absolute amount of 16S rRNA genes was significantly increased in AF of preterm deliveries and detailed profiling revealed a reduced alpha diversity and a significant change in beta diversity with a reduced relative abundance of 16S rRNA genes indicative for Lactobacillus and Acetobacter while Fusobacterium, Pseudomonas, Ureaplasma and Staphylococcus 16S rRNA gene prevailed. Although classification of BPD by disease severity revealed equivalent absolute 16S rRNA gene abundance and alpha and beta diversity in no, mild and moderate/severe BPD groups, for some 16S rRNA genes differences were observed in AF samples. Bacterial signatures of infants with moderate/severe BPD showed predominance of 16S rRNA genes belonging to the Escherichia-Shigella cluster while Ureaplasma and Enterococcus species were enriched in AF samples of infants with mild BPD.

CONCLUSIONS

Our study identified distinct and diverse intrauterine 16S rRNA gene patterns in preterm infants immediately before birth, differing from the 16S rRNA gene signature of intact pregnancies. The distinct 16S rRNA gene signatures at birth derive from bacteria with varying pathogenicity to the immature lung and are suited to identify preterm infants at risk. Our results emphasize the prenatal impact to the origins of BPD.

Nutrition-based implications and therapeutics in the development and recovery of bronchopulmonary dysplasia

Premature births account for over 10% of live births worldwide. Bronchopulmonary dysplasia (BPD) represents a severe sequela in neonates born very prematurely and remains the most common chronic neonatal lung disease, often leading to serious adverse consequences in adulthood. Nutrition plays a crucial role in lung development and repair. Ongoing research has primarily focused on the pathogenesis and prevention of BPD in preterm birth. However, infants with established BPD need specialist medical care that persists throughout their hospitalization and continues after discharge. This manuscript aims to highlight the impact of growth and nutrition on BPD and highlight research gaps to provide direction for future studies. Protective practices include ensuring adequate early energy delivery through parenteral nutrition and enteral feedings while carefully monitoring total fluid intake and the use of breast milk over formula. These nutritional strategies remain the same for infants with established BPD with the addition of limiting the use of diuretics and steroids; but if employed, monitoring carefully without compromising total energy delivery. Functional nutrient supplements with a potential protective role against BPD are revisited, despite the limited evidence of their efficacy, including vitamins, trace elements, zinc, lipids, and sphingolipids. Planning post-intensive care and outpatient longitudinal nutrition support is critical in caring for an infant with established BPD.

Noninvasive Ventilation and Rapid Enteral Feeding Advances in Preterm Infants-2-Year Follow-Up of the STENA-Cohort

The importance of nutritional supply for somatic growth and neurodevelopmental outcome in very-low-birthweight infants is an established medical strategy for reducing long-term morbidities. Our cohort study on rapid enteral feeding advances using a standardized protocol (STENA) previously demonstrated a 4-day reduction of parenteral nutrition. STENA did not impede the success of noninvasive ventilations strategies but significantly less infants required mechanical ventilation. Most importantly, STENA resulted in improved somatic growth at 36 weeks of gestation. Here, we evaluated our cohort for psychomotor outcomes and somatic growth at 2 years of age. n = 218 infants of the original cohort were followed-up (74.4%). Z-scores for weight and length did not differ but the benefits of STENA for head circumference persisted until the age of 2 years (p = 0.034). Concerning the psychomotor outcome, we neither found any statistically significant differences in the mental developmental index (MDI) (p = 0.738), norin the psychomotor developmental index (PDI) (p = 0.122). In conclusion, our data adds important insights on the topic of rapid enteral feeding advances and confirms the safety of STENA with respect to somatic growth and psychomotor outcome measures.

[Influencing factors for the development and severity of bronchopulmonary dysplasia in preterm infants with a gestational age of <32 weeks and a birth weight of <1 500 g]

OBJECTIVES

To study the influencing factors for the development and severity of bronchopulmonary dysplasia (BPD) in preterm infants with a gestational age of <32 weeks and a birth weight of <1 500 g.

METHODS

A retrospective analysis was performed on the medical data of preterm infants with a gestational age of <32 weeks and a birth weight of <1 500 g who were admitted to Women and Children's Hospital Affiliated to Xiamen University from January 1, 2017 to December 31, 2021. According to oxygen dependence on day 28 after birth, they were divided into two groups: BPD (n=218) and non-BPD (n=142). According to disease severity based on oxygen concentration required at the corrected age of 36 weeks or at discharge, the infants with BPD were divided into two groups: mild BPD (n=154) and moderate/severe BPD (n=64). Indices such as perinatal data and nutritional status were compared between groups. The multivariate logistic regression analysis was used to determine the influencing factors for BPD and its severity.

RESULTS

The incidence rate and severity of BPD increased with the reduction in gestational age and birth weight (P<0.05). The multivariate logistic regression analysis showed that a long duration of invasive mechanical ventilation (OR=1.320, P<0.05), hemodynamically significant patent ductus arteriosus (OR=2.032, P<0.05), and a prolonged time to reach oral calorie goal of 110 kcal/(kg·d) (OR=1.041, P<0.05) were risk factors for BPD, while an older gestational age was a protective factor against BPD (OR=0.535, P<0.05). Early-onset sepsis (OR=2.524, P<0.05) and a prolonged time to reach oral calorie goal of 110 kcal/(kg·d) (OR=1.029, P<0.05) were risk factors for moderate/severe BPD, while a high mean weight growth velocity was a protective factor against moderate/severe BPD (OR=0.906, P<0.05).

CONCLUSIONS

The incidence rate and severity of BPD in preterm infants with a gestational age of <32 weeks and a birth weight of <1 500 g can be reduced by shortening the duration of invasive mechanical ventilation, giving early treatment of early-onset sepsis and hemodynamically significant patent ductus arteriosus, adopting active enteral nutritional strategies, and increasing mean weight growth velocity.

Insights into the Black Box of Intra-Amniotic Infection and Its Impact on the Premature Lung: From Clinical and Preclinical Perspectives

Intra-amniotic infection (IAI) is one major driver for preterm birth and has been demonstrated by clinical studies to exert both beneficial and injurious effects on the premature lung, possibly due to heterogeneity in the microbial type, timing, and severity of IAI. Due to the inaccessibility of the intra-amniotic cavity during pregnancies, preclinical animal models investigating pulmonary consequences of IAI are indispensable to elucidate the pathogenesis of bronchopulmonary dysplasia (BPD). It is postulated that on one hand imbalanced inflammation, orchestrated by lung immune cells such as macrophages, may impact on airway epithelium, vascular endothelium, and interstitial mesenchyme, resulting in abnormal lung development. On the other hand, excessive suppression of inflammation may as well cause pulmonary injury and a certain degree of inflammation is beneficial. So far, effective strategies to prevent and treat BPD are scarce. Therapeutic options targeting single mediators in signaling cascades and mesenchymal stromal cells (MSCs)-based therapies with global regulatory capacities have demonstrated efficacy in preclinical animal models and warrant further validation in patient populations. Ante-, peri- and postnatal exposome analysis and therapeutic investigations using multiple omics will fundamentally dissect the black box of IAI and its effect on the premature lung, contributing to precisely tailored and individualized therapies.

Compatibility of rapid enteral feeding advances and noninvasive ventilation in preterm infants-An observational study

AIM

To evaluate safety and clinical outcome of rapid enteral feeding advances in preterm infants <1500 g birthweight (BW).

METHODS

In this single-center retrospective cohort study, 293 preterm infants born during 2015-2018 were comparatively analyzed before (n = 145) and after (n = 148) the implementation of a rapid enteral feeding protocol with daily milk increments of 20-30 ml/kg of body weight. Major outcome parameters were focused toward pulmonary morbidities and nutritional variables.

RESULTS

Preterm infants in the rapid feeding advancement group were more successfully stabilized on noninvasive ventilation (p < 0.001) never requiring mechanical ventilation. Duration of respiratory support (0.465) and frequency of bronchopulmonary dysplasia (BPD) (p = 0.341) and severe BPD (0.273) did not differ between both groups. Furthermore, patients in the rapid feeding group achieved full volume feedings faster (p < 0.001), regained BW earlier (p = 0.009), and displayed significantly improved somatic growth at 36 weeks gestational age (p < 0.001). There was no increased risk for further morbidities of prematurity including feeding intolerance, necrotizing enterocolitis (NEC), and focal intestinal perforation.

CONCLUSION

Rapid enteral feeding advancements in preterm infants <1500 g BW are safe and do not impede stabilization on noninvasive ventilation.

When inflammation meets lung development-an update on the pathogenesis of bronchopulmonary dysplasia

Even more than 50 years after its initial description, bronchopulmonary dysplasia (BPD) remains one of the most important and lifelong sequelae following premature birth. Tremendous efforts have been undertaken since then to reduce this ever-increasing disease burden but a therapeutic breakthrough preventing BPD is still not in sight. The inflammatory response provoked in the immature lung is a key driver of distorted lung development and impacts the formation of alveolar, mesenchymal, and vascular structures during a particularly vulnerable time-period. During the last 5 years, new scientific insights have led to an improved pathomechanistic understanding of BPD origins and disease drivers. Within the framework of current scientific progress, concepts involving disruption of the balance of key inflammatory and lung growth promoting pathways by various stimuli, take center stage. Still today, the number of efficient therapeutics available to prevent BPD is limited to a few, well-established pharmacological interventions including postnatal corticosteroids, early caffeine administration, and vitamin A. Recent advances in the clinical care of infants in the neonatal intensive care unit (NICU) have led to improvements in survival without a consistent reduction in the incidence of BPD. Our update provides latest insights from both preclinical models and clinical cohort studies and describes novel approaches to prevent BPD.

Ventilation-Induced Lung Injury (VILI) in Neonates: Evidence-Based Concepts and Lung-Protective Strategies

Supportive care with mechanical ventilation continues to be an essential strategy for managing severe neonatal respiratory failure; however, it is well known to cause and accentuate neonatal lung injury. The pathogenesis of ventilator-induced lung injury (VILI) is multifactorial and complex, resulting predominantly from interactions between ventilator-related factors and patient-related factors. Importantly, VILI is a significant risk factor for developing bronchopulmonary dysplasia (BPD), the most common chronic respiratory morbidity of preterm infants that lacks specific therapies, causes life-long morbidities, and imposes psychosocial and economic burdens. Studies of older children and adults suggest that understanding how and why VILI occurs is essential to developing strategies for mitigating VILI and its consequences. This article reviews the preclinical and clinical evidence on the pathogenesis and pathophysiology of VILI in neonates. We also highlight the evidence behind various lung-protective strategies to guide clinicians in preventing and attenuating VILI and, by extension, BPD in neonates. Further, we provide a snapshot of future directions that may help minimize neonatal VILI.

Enteral Feeding/Total Fluid Intake Ratio Is Associated With Risk of Bronchopulmonary Dysplasia in Extremely Preterm Infants

BACKGROUND

Nutrition is an essential factor in preventing and managing bronchopulmonary dysplasia (BPD), a multifactorial chronic respiratory disease in premature infants. This study examined the association between nutritional intakes during the first 2 weeks of life and BPD in extremely preterm infants.

METHODS

A retrospective single-center cohort study was performed in infants born <28 weeks' gestational age or with a birth weight <1,000 g. Intake of energy and ratio of enteral feeding/ total fluid intake during the first 2 weeks of life and association with outcome of BPD were examined.

RESULTS

134 infants were included in our study, and 43 infants (32.1%) developed BPD. During the first 2 weeks of life, the average of total caloric intake and the ratio of enteral feeding/ total fluid intake were significantly lower in the BPD group (total caloric intake:91.90 vs. 95.72 kcal/kg/d, p < 0.05, ratio of enteral feeding/total fluid intake: 0.14 vs. 0.18, p < 0.05), while the average of total fluid intake, caloric and protein intake from parenteral nutrition did not differ between the groups. The ratio of enteral feeding/ total fluid intake during the second week were significantly lower in the BPD group (0.21 vs. 0.28, p < 0.05), while this ratio during the first week did not differ between the groups. An increase of 10% in the ratio of enteral feeding/ total fluid intake during the second week of life significantly reduced the risk of BPD (OR 0.444, 95% CI: 0.270-0.731).

CONCLUSIONS

A higher ratio of enteral feeding/ total fluid intake was associated with a lower risk for BPD. Early and rapidly progressive enteral nutrition should be encouraged in extremely preterm infants in the absence of feeding intolerance.

Respiratory distress syndrome management in resource limited settings-Current evidence and opportunities in 2022

The complications of prematurity are the leading cause of neonatal mortality worldwide, with the highest burden in the low- and middle-income countries of South Asia and Sub-Saharan Africa. A major driver of this prematurity-related neonatal mortality is respiratory distress syndrome due to immature lungs and surfactant deficiency. The World Health Organization's Every Newborn Action Plan target is for 80% of districts to have resources available to care for small and sick newborns, including premature infants with respiratory distress syndrome. Evidence-based interventions for respiratory distress syndrome management exist for the peripartum, delivery and neonatal intensive care period- however, cost, resources, and infrastructure limit their availability in low- and middle-income countries. Existing research and implementation gaps include the safe use of antenatal corticosteroid in non-tertiary settings, establishing emergency transportation services from low to high level care facilities, optimized delivery room resuscitation, provision of affordable caffeine and surfactant as well as implementing non-traditional methods of surfactant administration. There is also a need to optimize affordable continuous positive airway pressure devices able to blend oxygen, provide humidity and deliver reliable pressure. If the high prematurity-related neonatal mortality experienced in low- and middle-income countries is to be mitigated, a concerted effort by researchers, implementers and policy developers is required to address these key modalities.

Oxygen Toxicity to the Immature Lung-Part II: The Unmet Clinical Need for Causal Therapy

Oxygen toxicity continues to be one of the inevitable injuries to the immature lung. Reactive oxygen species (ROS) production is the initial step leading to lung injury and, subsequently, the development of bronchopulmonary dysplasia (BPD). Today, BPD remains the most important disease burden following preterm delivery and results in life-long restrictions in lung function and further important health sequelae. Despite the tremendous progress in the pathomechanistic understanding derived from preclinical models, the clinical needs for preventive or curative therapies remain unmet. This review summarizes the clinical progress on guiding oxygen delivery to the preterm infant and elaborates future directions of research that need to take into account both hyperoxia and hypoxia as ROS sources and BPD drivers. Many strategies have been tested within clinical trials based on the mechanistic understanding of ROS actions, but most have failed to prove efficacy. The majority of these studies were tested in an era before the latest modes of non-invasive respiratory support and surfactant application were introduced or were not appropriately powered. A comprehensive re-evaluation of enzymatic, antioxidant, and anti-inflammatory therapies to prevent ROS injury is therefore indispensable. Strategies will only succeed if they are applied in a timely and vigorous manner and with the appropriate outcome measures.