Very preterm neonates receiving "aggressive" nutrition and early nCPAP had similar long-term respiratory outcomes as term neonates

Impaired lung function and associated risk factors in children born prematurely: a systematic review and meta-analysis

BACKGROUND

Immature lung development and respiratory morbidity place preterm-born children at high risk of long-term pulmonary sequelae. This systematic review and meta-analysis aims to quantify lung function in preterm-born children and identify risk factors for a compromised lung function.

METHODS

We searched MEDLINE, Embase, Cochrane Library, Web of Science and Scopus for relevant studies published on preterm cohorts born since 1990. Studies comparing forced expiratory volume in 1 s (FEV1) in preterm-born children aged ≥5 years to term-born controls or normative data were included. Study quality was assessed using the Newcastle-Ottawa Scale for cohort studies. Standardised mean differences in FEV1 and secondary spirometry outcomes per study were pooled using meta-analysis. The impact of different demographic and neonatal variables on studies' FEV1 effect sizes was investigated by meta-regression analyses. Certainty of evidence was assessed using the Grading of Recommendations, Assessment, Development, and Evaluations framework.

RESULTS

We identified 42 studies with unique cohorts including 4743 preterm children and 9843 controls. Median gestational age in the studies was 28.0 weeks and age at assessment ranged from 6.7 to 16.7 years. Preterm children had lower FEV1 than controls (-0.58 sd, 95% CI -0.69- -0.47 sd, p<0.001) resulting in a relative risk of 2.9 (95% CI 2.4-3.4) for abnormal outcome, with high certainty of evidence. FEV1 was significantly associated with gestational age, birthweight, bronchopulmonary dysplasia and invasive mechanical ventilation in univariate meta-regression analyses (R2=36-96%).

CONCLUSION

This systematic review shows robust evidence of impaired lung function in preterm-born children with a high certainty of evidence.

Temporal Dynamics of Oxidative Stress and Inflammation in Bronchopulmonary Dysplasia

Bronchopulmonary dysplasia (BPD) is the most common lung complication of prematurity. Despite extensive research, our understanding of its pathophysiology remains limited, as reflected by the stable prevalence of BPD. Prematurity is the primary risk factor for BPD, with oxidative stress (OS) and inflammation playing significant roles and being closely linked to premature birth. Understanding the interplay and temporal relationship between OS and inflammation is crucial for developing new treatments for BPD. Animal studies suggest that OS and inflammation can exacerbate each other. Clinical trials focusing solely on antioxidants or anti-inflammatory therapies have been unsuccessful. In contrast, vitamin A and caffeine, with antioxidant and anti-inflammatory properties, have shown some efficacy, reducing BPD by about 10%. However, more than one-third of very preterm infants still suffer from BPD. New therapeutic agents are needed. A novel tripeptide, N-acetyl-lysyltyrosylcysteine amide (KYC), is a reversible myeloperoxidase inhibitor and a systems pharmacology agent. It reduces BPD severity by inhibiting MPO, enhancing antioxidative proteins, and alleviating endoplasmic reticulum stress and cellular senescence in a hyperoxia rat model. KYC represents a promising new approach to BPD treatment.

Nutrition and Growth of Preterm Neonates during Hospitalization: Impact on Childhood Outcomes

The Special Issue has been completed with the publication of 13 review and research articles [...].

Are the current feeding volumes adequate for the growth of very preterm neonates?

Postnatal growth failure, a common problem in very preterm neonates associated with adverse neurodevelopmental outcome, has recently been shown not to be inevitable. There is a wide discussion regarding feeding practices of very preterm neonates, specifically regarding feeding volumes and nutrients supply to avoid postnatal growth failure. Current guidelines recommend an energy intake of 115–140 kcal /kg per d with a considerably higher upper limit of 160 kcal/kg per d. The feeding volume corresponding to this energy supply is not higher than 200 ml/kg in most cases. From the other side, randomised and observational studies used higher feeding volumes, and these were associated with better weight gain and growth, while no complications were noted. Taking into account the above, nutritional practices should be individualised in each very and extremely preterm infant trying to reduce postnatal growth failure, pointing out that available data are inconclusive regarding the effect of high-volume feeds on growth. Large clinical trials are necessary to conclude in the best feeding practices of very preterm neonates.

An Update on Lung Function of Extremely and Very Preterm Infants in Later Life: The Role of Early Nutritional Interventions

Birth occurring at ≤32 weeks' gestation ("very preterm") or at ≤28 weeks' gestation ("extremely preterm") potentially poses considerable health problems for the neonate, including respiratory sequelae, not only during the immediate newborn period, but throughout childhood and into adulthood. With the progressive improvements in neonatal care, the survival of extremely preterm and very preterm neonates has improved substantially. However, a considerable percentage of these infants suffer dysfunctions that may trigger, at some stage later in life, the onset of respiratory morbidities. The interruption of the normal development of the respiratory tract caused by preterm birth, in combination with postnatal lung injury caused by various interventions, e.g., mechanical ventilation and oxygen therapy, increases the risk ofthe development of long-term respiratory deficits in survivors. Those infants that are most affected are those who develop chronic lung disease of prematurity (also called bronchopulmonary dysplasia, BPD), but impaired lung function can develop irrespective of BPD diagnosis. Apart from indicating abnormal lung function in survivors of extreme prematurity, recent long-term follow-up studies also emphasize the crucial role of early nutritional intake as an effective strategy, which promotes lung growth and repair. This article will update the associations between extremely/very preterm birth with long-term respiratory outcomes. It will also discuss the protective effect of nutritional interventions, focusing on recently published follow-up data.

Extrauterine Growth Restriction and Optimal Growth of Very Preterm Neonates: State of the Art

Over the last few decades, there has been an ongoing debate over both the optimal feeding mode for very premature neonates (VPN) as well as what their optimal growth should be. Despite the American Academy of Pediatric declaring since 1997 that the growth of VPN should follow the trajectory of intrauterine fetal growth, differences of opinion persist, feeding policies keep changing, and the growth and development of VPN remains extremely variable not only between countries, but even between neighboring neonatal units. Even the appropriate terminology to express poor postnatal growth (extrauterine growth restriction (EGR) and postnatal growth failure (PGF)) remains a subject of ongoing discussion. A number of recent publications have shown that by implementing breast milk fortification and closely following growth and adjusting nutrition accordingly, as per the consensus guidelines of the major Neonatal Societies, we could achieve growth that closely follows birth centiles. A recent position paper from EPSGAN recommending targeted nutritional support to cover the energy and protein deficits sustained by VPN during periods of critical illness further strengthens the above findings. Conclusion: We can promote better growth of VPN by ensuring a stable administration of sufficient calories and protein, especially in the first 2 weeks of life, implementing breast milk fortification, covering energy and protein deficits due to critical illness, and increasing feeding volumes as per the latest guidelines. The adoption of universal protocol for nutrition and growth of VPN is essential and will enable better monitoring of long-term outcomes for this population.

Increasing airway obstruction through life following bronchopulmonary dysplasia: a meta-analysis

Background

Few studies exist investigating lung function trajectories of those born preterm; however growing evidence suggests some individuals experience increasing airway obstruction throughout life. Here we use the studies identified in a recent systematic review to provide the first meta-analysis investigating the impact of preterm birth on airway obstruction measured by the forced expiratory volume in 1 s (FEV1) to forced vital capacity (FVC) ratio.

Methods

Cohorts were included for analysis if they reported FEV1/FVC in survivors of preterm birth (<37 weeks' gestation) and control populations born at term. Meta-analysis was performed using a random effect model, expressed as standardised mean difference (SMD). Meta-regression was conducted using age and birth year as moderators.

Results

55 cohorts were eligible, 35 of which defined groups with bronchopulmonary dysplasia (BPD). Compared to control populations born at term, lower values of FEV1/FVC were seen in all individuals born preterm (SMD -0.56), with greater differences seen in those with BPD (SMD -0.87) than those without BPD (SMD -0.45). Meta-regression identified age as a significant predictor of FEV1/FVC in those with BPD with the FEV1/FVC ratio moving -0.04 sds away from the term control population for every year of increased age.

Conclusions

Survivors of preterm birth have significantly increased airway obstruction compared to those born at term with larger differences in those with BPD. Increased age is associated with a decline in FEV1/FVC values suggesting increased airway obstruction over the life course.

Geographical Differences and Temporal Improvements in Forced Expiratory Volume in 1 Second of Preterm-Born Children: A Systematic Review and Meta-analysis

Importance

Although preterm birth is associated with later deficits in lung function, there is a paucity of information on geographical differences and whether improvements occur over time, especially after surfactant was introduced.

Objective

To determine deficits in percentage predicted forced expiratory volume in 1 second (%FEV1) in preterm-born study participants, including those with bronchopulmonary dysplasia (BPD) in infancy, when compared with term-born control groups.

Data Sources

Eight databases searched up to December 2021.

Study Selection

Studies reporting spirometry for preterm-born participants with or without a term-born control group were identified.

Data Extraction and Synthesis

Data were extracted and quality assessed by 1 reviewer and checked by another. Data were pooled using random-effects models and analyzed using Review Manager and the R metafor package.

Main Outcomes and Measures

Deficits in %FEV1 between preterm-born and term groups. Associations between deficits in %FEV1 and year of birth, age, introduction of surfactant therapy, and geographical region of birth and residence were also assessed.

Results

From 16 856 titles, 685 full articles were screened: 86 with and without term-born control groups were included. Fifty studies with term controls were combined with the 36 studies from our previous systematic review, including 7094 preterm-born and 17 700 term-born participants. Of these studies, 45 included preterm-born children without BPD, 29 reported on BPD28 (supplemental oxygen dependency at 28 days), 26 reported on BPD36 (supplemental oxygen dependency at 36 weeks' postmenstrual age), and 86 included preterm-born participants. Compared with the term-born group, the group of all preterm-born participants (all preterm) had deficits of %FEV1 of -9.2%; those without BPD had deficits of -5.8%, and those with BPD had deficits of approximately -16% regardless of whether they had BPD28 or BPD36. As year of birth increased, there was a statistically significant narrowing of the difference in mean %FEV1 between the preterm- and term-born groups for the all preterm group and the 3 BPD groups but not for the preterm-born group without BPD. For the all BPD group, when compared with Scandinavia, North America and western Europe had deficits of -5.5% (95% CI, -10.7 to -0.3; P = .04) and -4.1% (95% CI, -8.8 to 0.5; P = .08), respectively.

Conclusions and Relevance

Values for the measure %FEV1 were reduced in preterm-born survivors. There were improvements in %FEV1 over recent years, but geographical region had an association with later %FEV1 for the BPD groups.

Impact of Illness Severity and Interventions on Successful Weaning from Nasal CPAP in Very Preterm Neonates: An Observational Study

This study aims to identify clinical variables that could affect successful weaning from nasal continuous positive airway pressure (NCPAP) in very preterm infants. Infants born at a gestational age (GA) of <32 weeks were retrospectively enrolled. Weaning from NCPAP was initiated when the infants were clinically stable. In the univariate analysis, GA, birth weight, body weight (BW) z-score at the time of successful NCPAP weaning, intubation, total duration of intubation, respiratory distress syndrome grade, APGAR score at the 1 and 5 min, initial shock, anemia, bronchopulmonary dysplasia, number of blood transfusions, total duration of dopamine use, administration of more than two doses of surfactant, use of aminophylline, use of a diuretic, and total duration of total parenteral nutrition were significantly associated with postmenstrual age (PMA) at the time of successful NCPAP weaning. Multivariate analysis showed that the total duration of intubation, bronchopulmonary dysplasia, and administration of more than two doses of surfactant were positively associated with PMA at the time of successful NCPAP weaning. A reverse association was noted between BW z-score and PMA at the time of successful NCPAP weaning. Sufficient nutrition and avoidance of further ventilator-induced lung injury could decrease NCPAP duration in very preterm infants.

"Aggressive" Feeding of Very Preterm Neonates and Body Mass Index at School Age

INTRODUCTION

The effects of "aggressive" neonatal feeding policies of very preterm neonates (VPN) and the risk of metabolic syndrome later in life remain questionable. We aimed to evaluate the effect of our "aggressive" nutrition policies of VPN during hospitalisation on body mass index (BMI) at ages 2 and 8 years.

MATERIALS AND METHODS

Eighty four VPN, who received "aggressive" nutrition during hospitalisation in an effort to minimise postnatal growth restriction (PGR) (group A), and 62 term neonates, as controls (group B), were enrolled in the study. Group A was further divided in four subgroups depending on the type (A1: fortified expressed breast milk and preterm formula; A2: exclusively preterm formula) and quantity of milk received (A3: maximum feeds 180-210 mL/kg/day; A4: maximum feeds 210 and up to 260 mL/kg/day). BMI was calculated at ages 2 and 8 years and plotted on the centile charts.

RESULTS

There was no significant difference in BMI between groups A and B at 2 and 8 years, respectively, in both absolute BMI values and their centile chart distribution. There was no significant difference in BMI at 2 and 8 years either between subgroups A1 and A2 or between subgroups A3 and A4.

CONCLUSIONS

"Aggressive" and individualised feeding policy for VPN did not affect the BMI and obesity rates at ages of 2 and 8 years in our study population. The type and quantity of milk feeds had no impact on their BMI at school age. Further larger studies are needed to confirm our results.

Variation in very preterm extrauterine growth in a European multicountry cohort

OBJECTIVE

Extrauterine growth restriction (EUGR) among very preterm infants is related to poor neurodevelopment, but lack of consensus on EUGR measurement constrains international research. Our aim was to compare EUGR prevalence in a European very preterm cohort using commonly used measures.

DESIGN

Population-based observational study.

SETTING

19 regions in 11 European countries.

PATIENTS

6792 very preterm infants born before 32 weeks' gestational age (GA) surviving to discharge.

MAIN OUTCOME MEASURES

We investigated two measures based on discharge-weight percentiles with (1) Fenton and (2) Intergrowth (IG) charts and two based on growth velocity (1) birth weight and discharge-weight Z-score differences using Fenton charts and (2) weight-gain velocity using Patel's model. We estimated country-level relative risks of EUGR adjusting for maternal and neonatal characteristics and associations with population differences in healthy newborn size, measured by mean national birth weight at 40 weeks' GA.

RESULTS

About twofold differences in EUGR prevalence were observed between countries for all indicators and these persisted after case-mix adjustment. Discharge weight <10th percentile using Fenton charts varied from 24% (Sweden) to 60% (Portugal) and using IG from 13% (Sweden) to 43% (Portugal), while low weight-gain velocity ranged from 35% (Germany) to 62% (UK). Mean term birth weight strongly correlated with both percentile-based measures (Spearman's rho=-0.90 Fenton, -0.84 IG, p<0.01), but not Patel's weight-gain velocity (rho: -0.38, p=0.25).

CONCLUSIONS

Very preterm infants have a high prevalence of EUGR, with wide variations between countries in Europe. Variability associated with mean term birth weight when using common postnatal growth charts complicates international benchmarking.

Transcutaneous carbon dioxide pattern and trend over time in preterm infants

BACKGROUND

Chronic lung disease remains a burden for extremely preterm infants. The changes in ventilation over time and optimal ventilatory management remains unknown. Newer, non-invasive technologies provide insight into these patterns.

METHODS

This single-center prospective cohort study enrolled infants ≤32 0/7 weeks. We obtained epochs of transcutaneous carbon dioxide (TcCO₂) measurements twice each week to describe the pattern of hypercarbia throughout their hospitalization.

RESULTS

Patterns of hypercarbia varied based on birth gestational age and post-menstrual age (PMA) (p = 0.03), regardless of respiratory support. Infants receiving the most respiratory support had values 16-21 mmHg higher than those on room air (p < 0.001). Infants born at the youngest gestational ages had the greatest total change but the rate of change was slower (p = 0.049) compared to infants born at later gestational ages. All infants had TcCO₂ values stabilize by 31-33 weeks PMA, when values were not significantly different compared to discharge. No rebound was observed when infants weaned off invasive support.

CONCLUSIONS

Hypercarbia improves as infants approached 31-33 weeks PMA. Hypercarbia was the highest in the most immature infants and improved with age and growth despite weaning respiratory support.

IMPACT

This study describes the evolution of hypercarbia as very preterm infants grow and develop. The pattern of ventilation is significantly different depending on the gestational age at birth and post-menstrual age. Average transcutaneous carbon dioxide (TCO₂) decreased over time as infants became more mature despite weaning respiratory support. This improvement was most significant in infants born at the lowest gestational ages.

Study on the Effect of Bilateral Mandible Distraction Osteogenesis About the Nutrition Status of Infants With Pierre-Robin Sequence

Objective: By comparing and studying the changes of food intake, weight, body length, BMI, blood albumin level and other indicators of infants with Pierre-Robin Sequence (PRS) before and after Bilateral Mandible Distraction Osteogenesis operation, to explore the effect of distraction osteogenesis on PRS patients about the improvement of nutrition status. Methods: The children with PRS who admitted to the Oral and Maxillofacial Surgery Department of Guangzhou Women and Children's Medical Center from July 2015 to December 2020 were selected. All patients accepted bilateral mandible distraction osteogenesis surgery, and the pre- and post-operative indicators were recorded, such as food intake, weight, length, blood albumin level and others. BMI was calculated based on the indicators mentioned above, and comparative statistical analysis was performed. Results: 1. All patients were fed with whole milk before the first surgery, and the average calorie per kg was 91.8 kcal/kg, significantly lower than the standard (100-150 kcal/kg), suggesting the overall nutritional intake of PRS patients is low; 2. t tests for independent samples were used to analyze the pre-operative and post-operative indicators. The WFA percentile increased from 14.16 ± 2.17 to 15.01 ± 1.85% (P = 0.0048), WFA z score increased from -2.40 ± 0.18 to -1.90 ± 0.14 after the surgery (P = 0.0010), LFA percentile increased from 20.04 ± 3.48 to 33.67 ± 4.29% (P = 0.0098), LFA z score increased from -2.09 ± 0.19 to -1.42 ± 0.23 (P = 0.0009), BMI z score increased from -1.95 ± 0.22 to -1.39 ± 0.16 (P = 0.0408), ALB raised from 37.06 ± 0.51 to 42.85 ± 0.30 g/L (P < 0.001), which indicating that the physique of patients improved after the distraction osteogenesis surgery, mainly was reflected by the lifting of weight and length growth curves; the body shape also improved, indicating that the patients' nutrition status after the surgery is also improved. Conclusion: Bilateral mandible distraction osteogenesis surgery has a positive effect on the nutrition status of children with PRS. This effect is mainly reflected by the improvements of the body physical indicators after surgery.

Caffeine and Gastric Emptying Time in Very Preterm Neonates

Background: Caffeine has been commonly used for prevention and treatment of apnea-related symptoms in premature infants. However, its side effects have not been thoroughly studied. We investigated whether caffeine affects gastric motility in very-preterm (VP) neonates. Methods: The study is a randomized crossover clinical trial. Twenty-two neonates with mean birth weight (BW) (standard deviation—SD) 1077 (229) g and mean gestational age (GA) (SD) 28.6 (2.1) weeks were recruited. Each neonate had its gastric emptying time checked twice with ultrasound assessment of changes in antral cross sectional area (ACSA). All neonates were sequentially allocated to the caffeine group (A) and the control group (B). Complications from the gastrointestinal tract were documented throughout the study. Results: Statistically significant difference was found with regards to the gastric emptying time [median, (range)] between caffeine and control group (p = 0.040). Additionally, in the neonates with BW 1000–1500 g and GA ≥ 28 weeks, the gastric emptying time (minutes) was significantly longer during caffeine treatment [44.5 (36–68.2)] and [40 (34.5–66.5)] respectively, as compared to the gastric emptying time during no caffeine treatment [27 (24.2–30)] (p = 0.002) and [27 (24.5–30)] (p = 0.001). The incidence of gastrointestinal (GI) complications was significantly greater in neonates receiving caffeine [6 (27.%)] as compared with those without caffeine treatment [1 (4.6%)] (p = 0.039). Conclusions: During caffeine treatment, a significantly delayed gastric emptying time was noted in all study neonates, especially in these with BW 1000–1500 g and those with GA ≥ 28 weeks. Further larger studies are necessary in order to confirm this interesting finding.

Reply: "It is Time for a Universal Nutrition Policy in Very Preterm Neonates during the Neonatal Period? Comment on: Applying Methods for Postnatal Growth Assessment in the Clinical Setting: Evaluation in a Longitudinal Cohort of Very Preterm Infants Nutrients 2019, 11, 2772"

We would like to thank Gounaris et al [...].

Intestinal Dysbiosis and the Developing Lung: The Role of Toll-Like Receptor 4 in the Gut-Lung Axis

Background

In extremely premature infants, postnatal growth restriction (PNGR) is common and increases the risk of developing bronchopulmonary dysplasia (BPD) and pulmonary hypertension (PH). Mechanisms by which poor nutrition impacts lung development are unknown, but alterations in the gut microbiota appear to play a role. In a rodent model, PNGR plus hyperoxia causes BPD and PH and increases intestinal Enterobacteriaceae, Gram-negative organisms that stimulate Toll-like receptor 4 (TLR4). We hypothesized that intestinal dysbiosis activates intestinal TLR4 triggering systemic inflammation which impacts lung development.

Methods

Rat pups were assigned to litters of 17 (PNGR) or 10 (normal growth) at birth and exposed to room air or 75% oxygen for 14 days. Half of the pups were treated with the TLR4 inhibitor TAK-242 from birth or beginning at day 3. After 14 days, pulmonary arterial pressure was evaluated by echocardiography and hearts were examined for right ventricular hypertrophy (RVH). Lungs and serum samples were analyzed by western blotting and immunohistochemistry.

Results

Postnatal growth restriction + hyperoxia increased pulmonary arterial pressure and RVH with trends toward increased plasma IL1β and decreased IκBα, the inhibitor of NFκB, in lung tissue. Treatment with the TLR4 inhibitor attenuated PH and inflammation.

Conclusion

Postnatal growth restriction induces an increase in intestinal Enterobacteriaceae leading to PH. Activation of the TLR4 pathway is a promising mechanism by which intestinal dysbiosis impacts the developing lung.