The evolution of modern respiratory care for preterm infants

Lung function outcomes in adults born extremely preterm across three decades of advancing perinatal medicine

AIM

Advances in perinatal medicine from 1980 to 2000 improved survival in extremely preterm (EP) neonates. Long-term effects of these developments remain unclear, and we aimed to investigate potential cohort effects on adult lung function.

METHODS

Three 18-year-old population-based cohorts born at ≤28 weeks gestation or with birthweight ≤1000 g during 1982-85, 1991-92 and 1999-2000 and term-controls underwent spirometry, body plethysmography, and tests of lung diffusing capacity, bronchodilator reversibility, and airway hyperresponsiveness. We used Welch's t-tests to compare term- with EP-born as a group and split by bronchopulmonary dysplasia (BPD), and regression models to test group/cohort interactions.

RESULTS

In all EP-born cohorts, z-scores for FEV1, FEV1/FVC, FEF25%-75%, DLCO and KCO were reduced compared with term-born. For the 82-85, 91-92 and 99-00 cohorts, deficits for z-FEV1 and z-DLCO were 1.23 and 0.53; 0.68 and 0.92; and 0.51 and 0.57, respectively (p ≤0.01 for all). Cohort analyses showed stable lung function across the three cohorts overall, but improvements across cohorts for the BPD subgroups in z-FEV1, z-FEV1/FVC, and z-FEF25%-75%.

CONCLUSION

Adults born EP across three formative decades of neonatal care had stable lung function overall, with notable improvements in BPD subgroups across cohorts.

Keep the PEEP: A quality improvement project assessing safety and feasibility of prolonged non-invasive positive end expiratory pressure

IntroductionInfants born less than 32-week gestation are at increased risk of respiratory distress syndrome due to underdeveloped pulmonary alveoli. Despite known respiratory benefits associated with positive end expiratory pressure (PEEP), our staff expressed concern that prolonged exposure to PEEP would contribute to increased risk of pneumothorax and delayed initiation of oral feeding.​ This quality improvement project aimed to standardize PEEP use with a guideline for early initiation, continuation, and subsequent discontinuation in infants born at less than 32-week gestation.MethodsWe developed and implemented a "Keep the PEEP" guideline, which included recommendations for initiation of PEEP at delivery, continuation through 32-week post-menstrual age (PMA), and discontinuation. Data collection occurred between July 2019-July 2021 (pre-intervention) and July 2021-August 2023 (post-intervention). Data analysis included run charts for monthly compliance, and bivariate analysis of pre- and post-intervention data. Interventions included team member education and team engagement through auditing.ResultsWe achieved a median compliance of 100% with PEEP use through 32-week PMA. We found no statistically significant differences in a pre- versus post-intervention comparison of pneumothorax incidence [14 versus 13, p = 0.86], bronchopulmonary dysplasia (BPD) incidence [82 versus 68, p = 0.65], median post-menstrual age at first oral feed [34.1 versus 34.1, p = 0.56], or median length of stay [55 versus 43, p = 0.2].ConclusionsWe successfully implemented a new respiratory guideline to standardize PEEP use in our unit during the study period. Despite initial concerns, the incidence of pneumothorax and the median gestational age at initiation of oral feedings remained unchanged.

The practice of a modified bubble CPAP therapy in a rural Sierra Leone SCBU-A pilot study

Background

Continuous Positive Airway Pressure (CPAP) is an effective intervention for managing neonatal respiratory distress. However, its implementation encounters numerous challenges in resource-limited settings. It is imperative for healthcare professionals to devise highly practical and cost-effective modifications to CPAP systems to address these challenges.

Objective

To evaluate the clinical efficacy and operational feasibility of a modified bubble CPAP therapy utilizing locally available materials in reducing respiratory distress and improving survival rates of neonates in the Special Care Baby Unit (SCBU) of the Sierra Leone-China Friendship Hospital.

Materials and methods

93 neonates with respiratory distress were divided into the control group (n = 48) for nasal cannula oxygen therapy and the observation group (n = 45) for modified bubble CPAP therapy. The modified CPAP device was constructed using locally available materials, such as drinking cups and modified nasal cannulas, with oxygen delivered via concentrators. Respiratory Severity Score, blood oxygen saturation, heart rate, and respiration were monitored with data recorded at admission and 8 h after intervention.

Results

After intervention, the neonates in the observation group showed significant improvements in all parameters: decreased RSS scores (7.40 ± 0.986 vs. 5.33 ± 1.447, P < 0.001), heart rate (153.13 ± 5.998 vs. 141.60 ± 8.830, P < 0.001), and respiratory rate (47.87 ± 4.103 vs. 43.47 ± 3.833, P < 0.01), and higher oxygen saturation (73.60% ± 10.636% vs. 91.07% ± 8.940%, P < 0.001) and survival rate (88% vs. 62.5%, P < 0.01).

Conclusion

The study indicated that the implementation of modified bubble CPAP therapy enhanced respiratory outcomes and increased survival rates among neonates experiencing respiratory distress in a resource-constrained setting in rural Sierra Leone.

The impact of neonatal care on moderate-risk infants: Evidence from healthcare use in the first two years of life

Advances in evidence-based neonatal care have led to large improvements in the survival rates of high-risk newborns. Yet studies have documented wide variation in the care of more prevalent moderate-risk infants, who comprise a much larger proportion of admissions to neonatal care. In this study, we build on a small literature which uses quasi-experimental design to understand the impact of neonatal care, and for the first time, examine this moderate-risk cohort of infants. We use individual-level data on the full population of births in the state of New South Wales, Australia to examine the impact of neonatal care on the healthcare use of moderate-risk infants in the first two years of life. We implement a regression discontinuity design exploiting admission protocols based on birthweight among neonatal units of three different and explicit levels of capability. Unlike previous studies, which examine differences in outcomes across the high-risk cut-off at 1500 g, our study examines differences for moderate-risk infants born near birthweight cut-offs closer to normal birth weight (2500 g). While admission to the neonatal unit jumps across the cut-off, we find modest impacts on downstream healthcare use, including both in-hospital and out-of-hospital care. However, we identify heterogeneous effects across varying capability levels. Moderate risk infants admitted to lower capability neonatal units received more cost-intensive care, resulting in reduced healthcare use following discharge from hospital, while the same was not observed for those admitted to the highest capability units. We suggest that this is due to more aggressive clinical management at lower capability units, and leave this as a priority for future research.

Interleukin-11 Is Involved in Hyperoxia-induced Bronchopulmonary Dysplasia in Newborn Mice by Mediating Epithelium-Fibroblast Cross-talk

BACKGROUND

Bronchopulmonary dysplasia (BPD) is a chronic lung disorder predominantly affecting preterm infants. Oxygen therapy, a common treatment for BPD, often leads to hyperoxia-induced pulmonary damage, particularly targeting alveolar epithelial cells (AECs). Crucially, disrupted lung epithelium-fibroblast interactions significantly contribute to BPD's pathogenesis. Previous studies on interleukin-11 (IL-11) in lung diseases have yielded conflicting results. Recent research, however, highlights IL-11 as a key regulator of fibrosis, stromal inflammation, and epithelial dysfunction. Despite this, the specific role of IL-11 in BPD remains underexplored. Our transcriptome analysis of normal and hyperoxia-exposed murine lung tissues revealed an increased expression of IL-11 RNA. This study aimed to investigate IL-11's role in modulating the disrupted interactions between AECs and fibroblasts in BPD.

METHODS

BPD was modeled in vivo by exposing C57BL/6J neonatal mice to hyperoxia. Histopathological changes in lung tissue were evaluated with hematoxylin-eosin staining, while lung fibrosis was assessed using Masson staining and immunohistochemistry (IHC). To investigate IL-11's role in pulmonary injury contributing to BPD, IL-11 levels were reduced through intraperitoneal administration of IL-11RαFc in hyperoxia-exposed mice. Additionally, MLE-12 cells subjected to 95% oxygen were collected and co-cultured with mouse pulmonary fibroblasts (MPFs) to measure α-SMA and Collagen I expression levels. IL-11 levels in the supernatants were quantified using an enzyme-linked immunosorbent assay (ELISA).

RESULTS

Both IHC and Masson staining revealed that inhibiting IL-11 expression alleviated pulmonary fibrosis in neonatal mice induced by hyperoxia, along with reducing the expression of fibrosis markers α-SMA and collagen I in lung tissue. In vitro analysis showed a significant increase in IL-11 levels in the supernatant of MLE-12 cells treated with hyperoxia. Silencing IL-11 expression in MLE-12 cells reduced α-SMA and collagen I concentrations in MPFs co-cultured with the supernatant of hyperoxia-treated MLE-12 cells. Additionally, ERK inhibitors decreased α-SMA and collagen I levels in MPFs co-cultured with the supernatant of hyperoxia-treated MLE-12 cells. Clinical studies found increased IL-11 levels in tracheal aspirates (TA) of infants with BPD.

CONCLUSION

This research reveals that hyperoxia induces IL-11 secretion in lung epithelium. Additionally, IL-11 derived from lung epithelium emerged as a crucial mediator in myofibroblast differentiation via the ERK signaling pathway, highlighting its potential therapeutic value in BPD treatment.

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.

Respect for history: an important dimension of contemporary obstetrics and gynecology

"Those who cannot remember the past are condemned to repeat it." This maxim underscores the importance of historical awareness in medicine, particularly for obstetricians and gynecologists (ObGyns). ObGyns significantly impact societal health through their care for pregnant women, fetuses, and newborns, uniquely positioning them to advocate for health initiatives with lasting societal benefits. Despite its importance, the history of medicine is underrepresented in medical curricula, missing opportunities to foster critical thinking and ethical decision-making. In today's climate of threatened reproductive rights, vaccine misinformation, and harmful ideologies, it is imperative for ObGyns to champion comprehensive historical education. The history of medicine, particularly in relation to societal issues - such as racism, discrimination, genocides, pandemics, and wars - provides valuable context for addressing challenges like maternal mortality, reproductive rights, vaccine hesitancy, and ethical issues. Understanding historical milestones and notable ethical breaches, such as the Tuskegee Study and the thalidomide tragedy, informs better practices and safeguards patient rights. Technological advancements in hygiene, antibiotics, vaccines, and prenatal care have revolutionized the field, yet contemporary ObGyns must remain vigilant about lessons learned from past challenges and successes. Integrating historical knowledge into medical training enhances clinical proficiency and ethical responsibility, fostering innovation and improving health outcomes. By reflecting on historical achievements and their impacts, current and future ObGyns can advance the field, ensuring comprehensive and ethically sound approaches to patient care. This paper highlights the crucial role of historical knowledge in shaping modern ObGyn practices, advocating for its integration into medical education to address contemporary health challenges and ethical considerations.

Transamniotic Delivery of Surfactant Protein B mRNA in a Healthy Model

INTRODUCTION

We sought to determine whether exogenous surfactant protein B (SPB) mRNA could be incorporated and translated by the fetal lung after simple transamniotic administration.

METHODS

Fetuses (n = 149) of twelve time-dated dams underwent intra-amniotic injections of either human SPB (hSPB) mRNA encapsulated into lipopolyplex (mRNA, n = 99) or lipopolyplex without mRNA (control; n = 50) on gestational day 17 (E17, term = E21-22). Lungs were screened for hSPB by enzyme-linked immunosorbent assay daily until term. Phosphatidylcholine (PC) (a surrogate for surfactant production) was measured in the amniotic fluid by fluorometric assay. Statistical analysis included nonparametric Wilcoxon rank sum test.

RESULTS

Significantly improved survival in the mRNA group compared to controls was observed at E18 (100% vs. 85.7%) and E20 (100% vs. 83.3%) (both p < 0.001). When controlled by mRNA-free injections, hSPB protein was detected in the mRNA group's lungs at E18, 19, and term (p = 0.002 to <0.001). Amniotic fluid PC levels were increased compared to control at term [285.9 (251.1, 363.9) μM versus 263.1 (222.8, 309.1) μM]; however, this did not reach significance (p = 0.33).

CONCLUSIONS

Encapsulated exogenous SPB mRNA can be incorporated and translated by fetal lung cells following intra-amniotic injection in a healthy rat model. Transamniotic mRNA delivery could become a novel strategy for perinatal surfactant protein replacement.

Non-Invasive Ventilatory Support in Preterm Neonates in the Delivery Room and the Neonatal Intensive Care Unit: A Short Narrative Review of What We Know in 2024

BACKGROUND

Guidelines recommend non-invasive ventilatory (NIV) support as first-line respiratory support mode in preterm infants as NIV is superior to intubation and mechanical ventilation in preventing death or bronchopulmonary dysplasia. However, with an ever-expanding variety of NIV modes available, there is much debate about which NIV modality should ideally be used, how, and when. The aims of this work were to summarise the evidence on different NIV modalities for both primary and secondary respiratory support: nCPAP, nasal high-flow therapy (nHFT), and nasal intermittent positive airway pressure ventilation (nIPPV), bi-level positive airway pressure (BiPAP), nasal high-frequency oscillatory ventilation (nHFOV), and nasally applied, non-invasive neurally adjusted ventilatory assist (NIV-NAVA) modes, with particular focus on their use in preterm infants.

SUMMARY

This is a narrative review with reference to published guidelines by European Consensus Guidelines on the Management of Respiratory Distress Syndrome: 2022 Update. nCPAP is currently the most commonly used primary and secondary NIV modality for premature infants. However, there is increasing evidence on the superiority of nIPPV over nCPAP. No beneficial effect was found for BiPAP over nCPAP. For the use of nHFT, nHFOV, and NIV-NAVA, more studies are needed to establish their place in neonatal respiratory care.

KEY MESSAGES

The superiority of nIPPV over nCPAP needs to be confirmed by contemporaneous trials comparing nCPAP to nIPPV at comparable mean airway pressures. Future trials should study NIV modalities in preterm infants with comparable respiratory pathology and indications, at comparable pressure settings and with different modes of synchronisation. Importantly, future trials should not exclude infants of the smallest gestational ages.

Prophylactic early low-dose hydrocortisone and survival without bronchopulmonary dysplasia among extremely preterm infants born at 22-27 weeks' gestation

OBJECTIVE

To compare survival without BPD among extremely preterm infants (EPI) who received prophylactic early low-dose hydrocortisone (PEH) with those who did not (non-PEH).

STUDY DESIGN

This single-center retrospective study compared risk-adjusted rates of survival without BPD, BPD, bowel perforation, and late-onset sepsis among infants (22-27 weeks' gestation at birth) who received PEH (n = 82) and who did not (n = 205).

RESULTS

Infants in the PEH group were of lower gestational age, lower birthweight, and higher day-1 risk of death/BPD. After adjusting for risk of death/BPD, PEH-treated infants demonstrated increased survival without BPD (aOR 2.04, 95%CI 1.1-3.7), and lower BPD rates (aOR 0.46, 95%CI 0.25-0.87). Importantly, bowel perforation or sepsis rate were similar among both groups.

CONCLUSION

After risk adjustment, PEH-treated infants demonstrated improved survival without BPD and did not increase rates of bowel perforation or sepsis. In our cohort of infants, PEH was safe and effective among the sickest preterm neonates.

Health-related quality of life in two birth cohorts of extremely preterm born adults

AIM

Investigate potential long-term cohort influences on health-related quality of life (HRQoL) in adults born extremely preterm (EP) during the 1980-90s, in view of advancements in neonatal care within that timeframe.

METHODS

Two cohorts of EP-born adults (82-85 cohort and 91-92 cohort) enrolling matched term controls, were compared. Participants were assessed at 18 years and again in their mid-twenties using the Child Health Questionnaire Children Form-87 (CHQ-CF87) and the Short Form Health Survey (SF-36).

RESULTS

At 18 years, 77 (90%) EP-born and 75 (93%) term controls had data, followed by 67 (78%) EP-born and 66 (82%) term controls in their mid-twenties. At 18 years, there were no differences across the birth decades, and EP-born and term-born reported relatively similar HRQoL scores. In the mid-twenties, birth decade did also not significantly impact HRQoL scores, although the EP-born 82-85 cohort scored numerically poorer than the 91-92 cohort in three domains. Term controls scored similarly across birth decade in all domains. Regarding influence from neonatal factors, postnatal corticosteroids had a negative impact in some domains.

CONCLUSION

No significant differences in HRQoL were observed between EP-born adults from the 82-85 cohort versus the 91-92 cohort, although the EP-born 82-85 cohort tended to score poorer in their mid-twenties.

Abdullah AS, Oishee I, Boyce C, Dey SK, Mannan MA, Moni SC, Shabuj MKH, Jahan I, Chowdhury RM, Afroze S, Wall S, Shahidullah M. Vayu bubble continuous positive airway pressure is a promising solution with favorable treatment outcomes for respiratory distress syndrome in newborns: a qualitative study in Bangladesh

Background

According to Bangladesh Demographic and Health Survey (2022), neonatal mortality, comprising 67% of under-5 deaths in Bangladesh, is significantly attributed to prematurity and low birth weight (LBW), accounting for 32% of neonatal deaths. Respiratory distress syndrome (RDS) is a prevalent concern among preterm and LBW infants, leading to substantial mortality. The World Health Organization (WHO) recommends bubble continuous positive airway pressure (bCPAP) therapy, but the affordability and accessibility of conventional bCPAP devices for a large number of patients become major hurdles in Bangladesh due to high costs and resource intensiveness. The Vayu bCPAP, a simple and portable alternative, offers a constant flow of oxygen-enriched, filtered, humidified, and pressurized air. Our study, conducted in five health facilities, explores the useability, acceptability, and perceived treatment outcome of Vayu bCPAP in the local context of Bangladesh.

Methods

A qualitative approach was employed in special care newborn units (SCANUs) of selected facilities from January to March 2023. Purposive sampling identified nine key informants, 40 in-depth interviews with service providers, and 10 focus group discussions. Data collection and analysis utilized a thematic framework approach led by trained anthropologists and medical officers.

Results

Service providers acknowledged Vayu bCPAP as a lightweight, easily movable, and cost-effective device requiring minimal training. Despite challenges such as consumable shortages and maintenance issues, providers perceived the device as user-friendly, operable with oxygen cylinders, and beneficial during referral transportation. Treatment outcomes indicated effective RDS management, reduced hospital stays, and decreased referrals. Though challenges existed, healthcare providers and facility managers expressed enthusiasm for Vayu bCPAP due to its potential to simplify advanced neonatal care delivery.

Conclusions

The Vayu bCPAP device demonstrated useability, acceptability, and favorable treatment outcomes in the care of neonates with RDS. However, sustained quality service necessitates continuous monitoring, mentoring and retention of knowledge and skills. Despite challenges, the enthusiasm among healthcare providers underscores the potential of Vayu bCPAP to save lives and simplify neonatal care delivery. Development of Standard Operating procedure on Vayu bCPAP is required for systematic implementation. Further research is needed to determine how the utilization of Vayu bCPAP devices enhances accessibility to efficient bCPAP therapy for neonates experiencing RDS.

Synergistic effects of achieving perinatal interventions on bronchopulmonary dysplasia in preterm infants

To investigate the effect of perinatal interventions on the risk of severe BPD (sBPD) and death in extremely preterm infants (EPIs) and their synergistic effects. This was a secondary analysis of the prospective cohort Chinese Neonatal Network (CHNN). Infants with a birth weight of 500 to 1250 g or 24-28 weeks completed gestational age were recruited. The impacts and the synergistic effects of six evidence-based perinatal interventions on the primary outcomes of sBPD and death were assessed by univariate and multivariable logistic regression modeling. Totally, 6568 EPIs were finally enrolled. Antenatal corticosteroid (adjusted OR, aOR, 0.74; 95%CI, 0.65-083), birth in centers with tertiary NICU (aOR, 0.64; 95%CI, 0.57-0.72), preventing intubation in the delivery room (aOR, 0.65; 95%CI, 0.58-0.73), early caffeine therapy (aOR, 0.59; 95%CI, 0.52-0.66), and early extubating (aOR, 0.42; 95%CI 0.37-0.47), were strongly associated with a lower risk of sBPD and death while early surfactant administration was associated with a lower risk of death (aOR, 0.84; 95%CI, 0.72, 0.98). Compared with achieving 0/1 perinatal interventions, achieving more than one intervention was associated with decreased rates (46.6% in 0/1 groups while 38.5%, 29.6%, 22.2%, 16.2%, and 11.7% in 2/3/4/5/6-intervention groups respectively) and reduced risks of sBPD/death with aORs of 0.76(0.60, 0.96), 0.55(0.43, 0.69), 0.38(0.30, 0.48), 0.28(0.22, 0.36), and 0.20(0.15, 0.27) in 2, 3, 4, 5, and 6 intervention groups respectively. Subgroup analyses showed consistent results.

CONCLUSION

Six perinatal interventions can effectively reduce the risk of sBPD and death in a synergistic form.

WHAT IS KNOWN

• Bronchopulmonary dysplasia (BPD) is a multifactorial chronic lung disease associated with prematurity. The effective management of BPD requires a comprehensive set of interventions. However, the extent to which these interventions can mitigate the risk of severe outcomes, such as severe BPD or mortality, or if they possess synergistic effects remains unknown.

WHAT IS NEW

• The implementation of various perinatal interventions, such as prenatal steroids, birth in centers with tertiary NICU, early non-Invasive respiratory support, surfactant administration within 2 hours after birth, early caffeine initiation within 3 days, and early extubation within 7 days after birth has shown promising results in the prevention of severe bronchopulmonary dysplasia (BPD) or mortality in extremely preterm infants. Moreover, these interventions have demonstrated synergistic effects when implemented in combination.

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.

Unravelling the respiratory health path across the lifespan for survivors of preterm birth

Many survivors of preterm birth will have abnormal lung development, reduced peak lung function and, potentially, an increased rate of physiological lung function decline, each of which places them at increased risk of chronic obstructive pulmonary disease across the lifespan. Current rates of preterm birth indicate that by the year 2040, around 50 years since the introduction of surfactant therapy, more than 700 million individuals will have been born prematurely-a number that will continue to increase by about 15 million annually. In this Personal View, we describe current understanding of the impact of preterm birth on lung function through the life course, with the aim of putting this emerging health crisis on the radar for the respiratory community. We detail the potential underlying mechanisms of prematurity-associated lung disease and review current approaches to prevention and management. Furthermore, we propose a novel way of considering lung disease after preterm birth, using a multidimensional model to determine individual phenotypes of lung disease-a first step towards optimising management approaches for prematurity-associated lung disease.

Case Report: Neurally adjusted ventilatory assist as an effective rescue treatment for pulmonary interstitial emphysema in extremely low birth weight infants

Pulmonary interstitial emphysema (PIE) is a complication observed in extremely low birth weight (ELBW) infants on mechanical ventilation. Despite various proposed therapeutic interventions, the success rates have shown inconsistency. Neurally adjusted ventilatory assist (NAVA) stands out as a novel respiratory support mode, offering lower pressure and tidal volume in comparison to conventional ventilation methods. In this case report, we present five ELBW infants with refractory PIE who were transitioned to NAVA ventilation. Following the switch to NAVA, all cases of PIE gradually resolved. In contrast to traditional modes, NAVA provided respiratory support with significantly lower fraction of inspired oxygen, reduced peak inspiratory pressure, diminished mean airway pressure, and decreased tidal volume within 7 days of NAVA utilization (p = 0.042, 0.043, 0.043, and 0.042, respectively). Consequently, we propose that NAVA could serve as a valuable rescue treatment for ELBW infants with PIE.

Trends in neonatal morbidity and mortality for very low birthweight infants: a 20-year single-center experience

OBJECTIVE

To describe trends in mortality and morbidity rates of very low birth weight infants as well as their pre-, peri- and postnatal characteristics over a period of 20 years' time.

METHODS

Retrospective study in all very low birth weight infants admitted to the neonatal intensive care unit of the University Hospitals Ghent from 1 January 2000, to 31 December 2020. Mortality was the primary outcome variable with major morbidities being co-primary outcome variables. Pre-, peri- and postnatal characteristics are secondary outcome variables. We compared pre-, peri- and postnatal characteristics, as well as major morbidities between different groups with comparable rates of mortality.

RESULTS

We included a total of 2037 very low birth weight infants and divided them in 3 epochs based on stepwise reductions in mortality in 2008 and 2013: 2000-2007 (n = 718), 2008-2012 (n = 506) and 2013-2020 (n = 813). Mortality decreased significantly over the years in all gestational ages, but predominantly in those with the youngest gestational age. Changes in obstetric and neonatal care were observed over time. Most significant changes were the increased use of antenatal corticosteroids, magnesium sulfate and surfactant. Intraventricular hemorrhage grade III/IV decreased significantly in all gestational ages. Significant increase in retinopathy of prematurity was observed. Bronchopulmonary dysplasia at 36 weeks and discharge home with oxygen is increasing in the total group. In those born below 26 weeks a slight increase in all major morbidities was observed especially of patent ductus arteriosus and retinopathy of prematurity. Increase of all other major morbidities seems to stabilize in epoch 3. The number of infants surviving without any major morbidity increases to almost 1/2 in all very low birth weight infants and to 1/10 in those born 24-25 weeks gestation.

CONCLUSION

Analysis of the real-life experience showed that survival in very low birth weight infants significantly increased over time. Evolution of major morbidities will have to be carefully watched in the future.

Respiratory outcomes in preterm infants following intravitreal bevacizumab for retinopathy of prematurity-a 10-year matched case study

OBJECTIVES

To evaluate respiratory outcomes in preterm infants with retinopathy of prematurity (ROP) following intravitreal bevacizumab injection (IVB).

METHODS

This single-centre study enroled preterm infants with a gestational age (GA) < 34 weeks or a birth weight (BW) < 1500 g with bilateral type 1 ROP who received a single IVB, and a treatment-free control group matched by GA, postmenstrual age, and respiratory status at the time of the IVB. The primary outcome was serial respiratory changes in mean airway pressure (MAP), fraction of inspired oxygen (FiO2), and respiratory severity score (RSS, MAP x FiO2) during the 28-day post-IVB/matching period and overall respiratory improvement at day 28 and at discharge. The duration of supplemental oxygen therapy following IVB/matching was documented.

RESULTS

A total of 5578 infants were included. Seventy-eight infants were enroled in the IVB group, and another 78 infants were matched as the control group. Both groups had downward trends in the MAP, FiO2, and RSS over the study period (all P < 0.001), but there were no between-group differences in these measures. The percentage of overall respiratory improvement was similar between the IVB and control groups, so was the duration of invasive and in-hospital oxygen ventilation. A lower percentage of oxygen dependence at discharge in the IVB group (P = 0.03) remained significant after adjusting for GA and BW.

CONCLUSIONS

This is a matched case study to evaluate respiratory outcomes in preterm infants following IVB for ROP. We found that the IVBs did not compromise respiratory outcomes in preterm infants during the 28-day post-IVB period and at discharge.

Higher versus lower nasal continuous positive airway pressure for extubation of extremely preterm infants in Australia (ÉCLAT): a multicentre, randomised, superiority trial

BACKGROUND

Extremely preterm infants often require invasive mechanical ventilation, and clinicians aim to extubate these infants as soon as possible. However, extubation failure occurs in up to 60% of extremely preterm infants and is associated with increased mortality and morbidity. Nasal continuous positive airway pressure (nCPAP) is the most common post-extubation respiratory support, but there is no consensus on the optimal nCPAP level to safely avoid extubation failure in extremely preterm infants. We aimed to determine if higher nCPAP levels compared with standard nCPAP levels would decrease rates of extubation failure in extremely preterm infants within 7 days of their first extubation.

METHODS

In this multicentre, randomised, open-label controlled trial done at three tertiary perinatal centres in Australia, we assigned extremely preterm infants to extubation to either higher nCPAP (10 cmH2O) or standard nCPAP (7 cmH2O). Infants were eligible if they were born at less than 28 weeks' gestation, were receiving mechanical ventilation via an endotracheal tube, and were being extubated for the first time to nCPAP. Eligible infants must have received previous treatment with exogenous surfactant and caffeine. Infants were ineligible if they were planned to be extubated to a mode of respiratory support other than nCPAP, if they had a known major congenital anomaly that might affect breathing, or if ongoing intensive care was not being provided. Parents or guardians provided prospective, written, informed consent. Infants were maintained within an assigned nCPAP range for a minimum of 24 h after extubation (higher nCPAP group 9-11 cmH2O and standard nCPAP group 6-8 cmH2O). Randomisation was stratified by both gestation (22-25 completed weeks or 26-27 completed weeks) and recruiting centre. The primary outcome was extubation failure within 7 days and analysis was by intention to treat. This trial was prospectively registered with the Australian New Zealand Clinical Trials Registry, number ACTRN12618001638224.

FINDINGS

Between March 3, 2019, and July 31, 2022, 483 infants were born at less than 28 weeks and admitted to the recruiting centres. 92 infants were not eligible, 172 were not approached, 65 families declined to participate, and 15 consented but were not randomly assigned. 139 infants were enrolled and randomly assigned, 70 to the higher nCPAP group and 69 to the standard nCPAP group. One infant in the higher nCPAP group was excluded from the analysis because consent was withdrawn after randomisation. 104 (75%) of 138 mothers were White. The mean gestation was 25·7 weeks (SD 1·3) and the mean birthweight was 777 grams (201). 70 (51%) of 138 infants were female. Extubation failure occurred in 24 (35%) of 69 infants in the higher nCPAP group and in 39 (57%) of 69 infants in the standard nCPAP group (risk difference -21·7%, 95% CI -38·5% to -3·7%). There were no significant differences in rates of adverse events between groups during the primary outcome period. Three patients died (two in the higher nCPAP group and one in the standard nCPAP group), pneumothorax occurred in one patient from each group, spontaneous intestinal perforation in three patients (two in the higher nCPAP group and one in the standard nCPAP group) and there were no events of pulmonary interstitial emphysema.

INTERPRETATION

Extubation of extremely preterm infants to higher nCPAP significantly reduced extubation failure compared with extubation to standard nCPAP, without increasing rates of adverse effects. Future larger trials are essential to confirm these findings in terms of both efficacy and safety.

FUNDING

National Health and Medical Research Council Centre for Research Excellence in Newborn Medicine, number 1153176.

Changes in neonatal morbidity, neonatal care practices, and length of hospital stay of surviving infants born very preterm in the Netherlands in the 1980s and in the 2000s: a comparison analysis with identical characteristics definitions

BACKGROUND

This study evaluates changes in the neonatal morbidity, the neonatal care practices, and the length of hospital stay of surviving very preterm (VP) infants born in the Netherlands in the 1980s and in the 2000s; a period over which historical improvements were introduced into neonatal care. We, herein, also study whether these changes in neonatal morbidity, neonatal care practices and length of hospital stay are associated with sociodemographic, prenatal, and infant characteristics.

METHODS

Two community-based cohorts from 1983 (POPS) and 2002-03 (LOLLIPOP) have provided the perinatal data for our study. The analysis enrolled 1,228 participants born VP (before the 32nd week of gestation) and surviving to 2 years of age without any severe congenital malformation. A rigorous harmonisation protocol ensured a precise comparison of the cohorts by using identical definitions of the perinatal characteristics.

RESULTS

In 2003, mothers were older when giving birth, had higher multiple birth rates, and significantly more parents had received higher education. In 2003, less VP infants had severe intraventricular haemorrhage and sepsis and relatively more received continuous positive airway pressure, mechanical ventilation and caffeine therapy than in 1983. Antenatal corticosteroids and surfactant therapy were provided only in 2003. The length of the stay in the neonatal intensive care unit and in hospital had decreased in 2003 by 22 and 11 days, respectively. Differences persisted after adjustment for sociodemographic, prenatal, and infant characteristics.

CONCLUSIONS

Neonatal morbidities of the surviving VP infants in this study have not increased, and exhibit improvements for various characteristics in two cohorts born 20 years apart with comparable gestational age and birth weight. Our data suggest that the improvements found are associated with more advanced therapeutic approaches and new national protocols in place, and less so with sociodemographic changes. This analysis provides a basis for further comparative analyses of the health and the development of VP children, particularly with regard to long-term outcomes.

Correlation between nasal anatomical characteristics in newborns and short binasal prong dimensions

OBJECTIVE

To correlate the nasal anatomical characteristics of newborns with the dimensions of short binasal prongs.

METHOD

Observational, cross-sectional study carried out in two hospitals in southern Brazil. The authors evaluated 1620 newborns with neonatal data and nasal dimensions. To measure the dimensions of the nasal region, the authors considered the width of the medial columella, the right nostril diameter, and the left nostril diameter. These data were correlated with the dimensions of two models of short binasal prongs.

RESULTS

Of the total newborns evaluated, 807 were female (49.8%), and 813 were male (50.2%). The majority were white (96.2%). The mean gestational age was 37.4 ± 2.9 weeks, ranging from 22 to 42 weeks. The birthweight was 2946.8 ± 699.3 g, ranging from 490.0 to 4740.0 g. Most of the nasal measures were significantly larger than both prong model measurements.

CONCLUSION

The sizes of short binasal prongs available on the Brazilian market do not match the nasal anatomical characteristics of newborns.

Gestational age at birth and hospitalisations for infections among individuals aged 0-50 years in Norway: a longitudinal, register-based, cohort study

Background

Preterm birth is associated with increased risk of childhood infections. Whether this risk persists into adulthood is unknown and limited information is available on risk patterns across the full range of gestational ages.

Methods

In this longitudinal, register-based, cohort study, we linked individual-level data on all individuals born in Norway (January 01, 1967-December 31, 2016) to nationwide hospital data (January 01, 2008-December 31, 2017). Gestational age was categorised as 23-27, 28-31, 32-33, 34-36, 37-38, 39-41, and 42-44 completed weeks. The analyses were stratified by age at follow-up: 0-11 months and 1-5, 6-14, 15-29, and 30-50 years. The primary outcome was hospitalisation due to any infectious disease, with major infectious disease groups as secondary outcomes. Adjusted hospitalisation rate ratios (RRs) for any infection and infectious disease groups were estimated using negative binomial regression. Models were adjusted for year of birth, maternal age at birth, parity, and sex, and included an offset parameter adjusted for person-time at risk.

Findings

Among 2,695,830 individuals with 313,940 hospitalisations for infections, we found a pattern of higher hospitalisation risk in lower gestational age groups, which was the strongest in childhood but still evident in adulthood. Comparing those born very preterm (28-31) and late preterm (34-36) to full-term (39-41 weeks), RRs (95% confidence interval) for hospitalisation for any infectious disease at ages 1-5 were 3.3 (3.0-3.7) and 1.7 (1.6-1.8), respectively. At 30-50 years, the corresponding estimates were 1.4 (1.2-1.7) and 1.2 (1.1-1.3). The patterns were similar for the infectious disease groups, including bacterial and viral infections, respiratory tract infections (RTIs), and infections not attributable to RTIs.

Interpretation

Increasing risk of hospitalisations for infections in lower gestational age groups was most prominent in children but still evident in adolescents and adults. Possible mechanisms and groups that could benefit from vaccinations and other prevention strategies should be investigated.

Funding

St. Olav's University Hospital and Norwegian University of Science and Technology, Norwegian Research Council, Liaison Committee for education, research and innovation in Central Norway, European Commission, Academy of Finland, Sigrid Jusélius Foundation, Foundation for Pediatric Research, and Signe and Ane Gyllenberg Foundation.

Cryptotanshinone affects HFL-1 cells proliferation by inhibiting cytokines secretion in RAW264.7 cells and ameliorates inflammation and fibrosis in newborn rats with hyperoxia induced lung injury

Objective: Bronchopulmonary dysplasia (BPD) is a common complication of prematurity and has no specific treatment option. Moreover, inflammation and fibrosis play a vital role in the development of BPD. Thus, this study aimed to explore the role of the anti-inflammatory and anti-fibrotic drug cryptotanshinone (CTS) in the treatment of inflammation and fibrosis in BPD. Methods: In vivo, Sprague-Dawley rats (male) were divided into air, hyperoxia and CTS groups with different dose interventions (7.5, 15, and 30 mg/kg). A BPD rat model was induced by continuous inhalation of hyperoxia (95%) for 7 days, during which different doses of CTS were injected intraperitoneally. Furthermore, histological examination, hydroxyproline content measurement, Western blot and real-time quantitative polymerase chain reaction were used to detect the levels of inflammation and fibrosis in the tissues. RAW264.7 cells exposed to 95% oxygen were collected and co-cultured with fibroblasts to determine the expression levels of α-SMA, collagen-Ⅰ and MMPs. The levels of pro-inflammatory cytokines such as TNF-α, IL-6 and pro-fibrotic factor TGF-β1 in the supernatants were measured using enzyme-linked immunosorbent assay. Results: Haematoxylin and eosin staining revealed that CTS reduced the inflammatory response in rat lungs. Masson staining revealed that CTS alleviated the level of pulmonary fibrosis. CTS also reduced the levels of TNF-α, IL-6 and TGF-β1 along with the expression of the fibrosis marker α-SMA in lung tissue. Similarly, in vitro analysis revealed that CTS decreased the levels of TNF-α, IL-6 and TGF-β1 expressed in RAW 264.7 cells, and reduced α-SMA, collagen-Ⅰ, MMPs concentrations in HFL-1 cells co-cultured with the supernatant of RAW264.7 cells after hyperoxia. Conclusion: CTS can attenuate the hyperoxia-induced inflammatory response and the level of fibrosis by regulating the levels of inflammatory factors and fibrotic factor TGF-β1 expressed by macrophages, thereby highlighting the therapeutic potential of CTS in the treatment of BPD.

Health service utilisation for acute respiratory infections in infants graduating from the neonatal intensive care unit: a population-based cohort study

BACKGROUND

Despite advances in neonatal intensive care, babies admitted to Neonatal Intensive Care Units (NICU) suffer from adverse outcomes. We aim to describe the longer-term respiratory infectious morbidity of infants discharged from NICU using state-wide population-based linked data in Western Australia.

STUDY DESIGN

We used probabilistically linked population-based administrative data to analyse respiratory infection morbidity in a cohort of 23,784 infants admitted to the sole tertiary NICU, born 2002-2013 with follow up to 2015. We analysed incidence rates of secondary care episodes (emergency department presentations and hospitalisations) by acute respiratory infection (ARI) diagnosis, age, gestational age and presence of chronic lung disease (CLD). Poisson regression was used to investigate the differences in rates of ARI hospital admission between gestational age groups and those with CLD, after adjusting for age at hospital admission.

RESULTS

From 177,367 child-years at risk (i.e., time that a child could experience an ARI outcome), the overall ARI hospitalisation rate for infants and children aged 0-8 years was 71.4/1000 (95% confidence interval, CI: 70.1, 72.6), with the highest rates in infants aged 0-5 months (242.9/1000). For ARI presentations to emergency departments, equivalent rates were 114/1000 (95% CI: 112.4, 115.5) and 337.6/1000, respectively. Bronchiolitis was the most common diagnosis among both types of secondary care, followed by upper respiratory tract infections. Extremely preterm infants (< 28 weeks gestation at birth) were 6.5 (95% CI: 6.0, 7.0) times more likely and those with CLD were 5.0 (95% CI: 4.7, 5.4) times more likely to be subsequently admitted for ARI than those in NICU who were not preterm or had CLD after adjusting for age at hospital admission.

CONCLUSIONS

There is an ongoing burden of ARI in children who graduate from the NICU, especially those born extremely preterm, that persists into early childhood. Early life interventions to prevent respiratory infections in these children and understanding the lifelong impact of early ARI on later lung health are urgent priorities.

Inter-rater reliability of the Silverman and Andersen index-a measure of respiratory distress in preterm infants

BACKGROUND

There are various methods of respiratory support available to optimize respiratory function in preterm infants. Respiratory scoring tools might provide information on which method to choose and the level and duration of support needed. Before implementing a respiratory scoring tool in our clinical practice, we aimed to test the inter- and intra-rater reliability of the Silverman and Andersen index (SA index) among neonatologists and nurses when applied to preterm infants on respiratory support. We also examined the association between the SA index and the electrical activity of the diaphragm (Edi signals).

METHODS

This was a multicenter study including three newborn intensive care units in Norway. Four neonatologists and 10 nurses applied the SA index when assessing 80 videos of 44 preterm infants on High Flow Nasal Cannula, Continuous Positive Airway Pressure and Neurally Adjusted Ventilatory Assist. The inter- and intra-rater reliability for the sum scores were measured by the intra-class correlation coefficient (ICC), and Kendall's W was used to assess the degree of agreement for each item. We quantified the association between the Edi signals and the SA index scores by the Spearman's correlation coefficient.

RESULTS

We found poor inter-rater reliability with an ICC for absolute agreement of 0.34 (95% CI: 0.20 to 0.53). There was fair agreement measuring each item separately for upper chest movements (Kendall's W 0.30), and moderate for lower chest movements (0.43) and xiphoid retractions (0.44). Expiratory grunting showed substantial agreement (0.67). The intra-rater reliability was good (ICC for absolute agreement 0.77; 95% CI: 0.68 to 0.84). We found a moderate positive correlation (r = 0.468, p = 0.028) between the maximum inspiratory diaphragm activity (Edi peak) and the mean inspiratory SA index scores.

CONCLUSION

Our study showed poor inter-rater and good intra-rater reliability of the SA index when nurses and neonatologists assessed videos of preterm infants on various types of respiratory support. Edi peak and SA index had a moderate positive correlation. Formal training might be essential to improve the inter-rater reliability.

TRIAL REGISTRATION

Registered 26th June 2017, ClinicalTrials.gov Identifier: NCT03199898.

Oxygen and mechanical stretch in the developing lung: risk factors for neonatal and pediatric lung disease

Chronic airway diseases, such as wheezing and asthma, remain significant sources of morbidity and mortality in the pediatric population. This is especially true for preterm infants who are impacted both by immature pulmonary development as well as disproportionate exposure to perinatal insults that may increase the risk of developing airway disease. Chronic pediatric airway disease is characterized by alterations in airway structure (remodeling) and function (increased airway hyperresponsiveness), similar to adult asthma. One of the most common perinatal risk factors for development of airway disease is respiratory support in the form of supplemental oxygen, mechanical ventilation, and/or CPAP. While clinical practice currently seeks to minimize oxygen exposure to decrease the risk of bronchopulmonary dysplasia (BPD), there is mounting evidence that lower levels of oxygen may carry risk for development of chronic airway, rather than alveolar disease. In addition, stretch exposure due to mechanical ventilation or CPAP may also play a role in development of chronic airway disease. Here, we summarize the current knowledge of the impact of perinatal oxygen and mechanical respiratory support on the development of chronic pediatric lung disease, with particular focus on pediatric airway disease. We further highlight mechanisms that could be explored as potential targets for novel therapies in the pediatric population.

Respiratory Management of the Preterm Infant: Supporting Evidence-Based Practice at the Bedside

Extremely preterm infants frequently require some form of respiratory assistance to facilitate the cardiopulmonary transition that occurs in the first hours of life. Current resuscitation guidelines identify as a primary determinant of overall newborn survival the establishment, immediately after birth, of adequate lung inflation and ventilation to ensure an adequate functional residual capacity. Any respiratory support provided, however, is an important contributing factor to the development of bronchopulmonary dysplasia. The risks correlated to invasive ventilatory techniques increase inversely with gestational age. Preterm infants are born at an early stage of lung development and are more susceptible to lung injury deriving from mechanical ventilation. Any approach aiming to reduce the global burden of preterm lung disease must implement lung-protective ventilation strategies that begin from the newborn’s first breaths in the delivery room. Neonatologists today must be able to manage both invasive and noninvasive forms of respiratory assistance to treat a spectrum of lung diseases ranging from acute to chronic conditions. We searched PubMed for articles on preterm infant respiratory assistance. Our narrative review provides an evidence-based overview on the respiratory management of preterm infants, especially in the acute phase of neonatal respiratory distress syndrome, starting from the delivery room and continuing in the neonatal intensive care unit, including a section regarding exogenous surfactant therapy.

Association Between Enteral Supplementation With High-Dose Docosahexaenoic Acid and Risk of Bronchopulmonary Dysplasia in Preterm Infants: A Systematic Review and Meta-analysis

Importance

High-dose docosahexaenoic acid (DHA), a long-chain polyunsaturated fatty acid, may affect the risk of bronchopulmonary dysplasia (BPD). However, high-level summative evidence supporting such clinical association in very preterm infants is lacking.

Objective

To examine the association between enteral supplementation with high-dose DHA during the neonatal period and the risk of BPD in preterm infants born at less than 29 weeks' gestation.

Data Sources

PubMed, Embase, Web of Science, Cochrane Central Register of Controlled Trials, medRxiv, and ClinicalTrials.gov were searched from inception to August 1, 2022, for eligible articles with no language restrictions.

Study Selection

Randomized clinical trials (RCTs) were eligible for inclusion (1) if their interventions involved direct administration of a minimum DHA supplementation of 40 mg/kg/d or breast milk or formula feeding of at least 0.4% of total fatty acids, and (2) if they reported data on either BPD, death, BPD severity, or a combined outcome of BPD and death.

Data Extraction and Synthesis

Two investigators completed independent review of titles and abstracts, full text screening, data extraction, and quality assessment using the Cochrane Risk of Bias 2.0. Risk ratios (RRs) with 95% CIs were pooled using random-effect meta-analyses.

Main Outcomes and Measures

Primary outcome was BPD using trial-specific definitions, which was further stratified for RCTs that used a more stringent BPD definition based on systematic pulse oximetry assessment at 36 weeks' postmenstrual age. Other outcomes were BPD, death, BPD severity, or combined BPD and death.

Results

Among the 2760 studies screened, 4 RCTs were included, which involved 2304 infants (1223 boys [53.1%]; mean [SD] gestational age, 26.5 [1.6] weeks). Enteral supplementation with high-dose DHA was associated with neither BPD (4 studies [n = 2186 infants]; RR, 1.07 [95% CI, 0.86-1.34]; P = .53; I2 = 72%) nor BPD or death (4 studies [n = 2299 infants]; RR, 1.04 [95% CI, 0.91-1.18]; P = .59; I2 = 61%). However, an inverse association with BPD was found in RCTs that used a more stringent BPD definition (2 studies [n = 1686 infants]; RR, 1.20 [95% CI, 1.01-1.42]; P = .04; I2 = 48%). Additionally, DHA was inversely associated with moderate-to-severe BPD (3 studies [n = 1892 infants]; RR, 1.16 [95% CI, 1.04-1.29]; P = .008; I2 = 0%).

Conclusions and Relevance

Results of this study showed that enteral supplementation with high-dose DHA in the neonatal period was not associated overall with BPD, but an inverse association was found in the included RCTs that used a more stringent BPD definition. These findings suggest that high-dose DHA supplementation should not be recommended to prevent BPD in very preterm infants.

Nasal intermittent positive pressure ventilation as a rescue therapy after nasal continuous positive airway pressure failure in infants with respiratory distress syndrome

OBJECTIVE

Evaluate whether nasal intermittent positive-pressure ventilation (NIPPV) as rescue therapy after initial nasal continuous positive airway (NCPAP) failure reduces need for invasive mechanical ventilation (IMV) in infants with respiratory distress syndrome (RDS).

DESIGN

Retrospective cohort involving 156 preterm infants who failed initial NCPAP and were then submitted to NIPPV rescue therapy and classified into NIPPV success or failure, according to need for IMV.

RESULT

Of all infants included, 85 (54.5%) were successfully rescued with NIPPV while 71 (45.5%) failed. The NIPPV success group had significantly lower rates of bronchopulmonary dysplasia, peri/intraventricular hemorrhage, patent ductus arteriosus and greater survival without morbidities (all p ≤ 0.01). Infants who failed NIPPV had earlier initial NCPAP failure (p = 0.09). In final logistic regression model, birthweight ≤1000 g and need for surfactant remained significant factors for NIPPV failure.

CONCLUSION

NIPPV rescue therapy reduced the need for IMV in infants that failed NCPAP and was associated with better outcomes.

Clinical impact of less invasive surfactant administration using video laryngoscopy in extremely preterm infants

BACKGROUND

Examine the real-world clinical impact of adopting less invasive surfactant administration (LISA) as the primary surfactant administration method in extremely preterm infants.

METHODS

Single-center pre-post cohort study conducted over a 4-year period comparing outcomes of spontaneously breathing inborn infants 24⁺⁰-28⁺⁶ weeks gestational age (GA) receiving surfactant via endotracheal tube (pre-cohort, n = 154) or LISA via thin catheter (post-cohort, n = 70). Primary outcome was need for invasive mechanical ventilation (IMV, ≥2 h) ≤72 h of age. Secondary outcomes were a composite of mortality, bronchopulmonary dysplasia, intraventricular hemorrhage ≥grade 3 or necrotizing enterocolitis, and its individual components. Groups were compared using propensity score methods, including covariates: GA, birth weight, sex, small for GA, SNAP II ≥20, premature rupture of membranes, maternal hypertension/diabetes, and C-section.

RESULTS

GA and birth weight were 27.1 (26, 28.1) weeks and 914 (230) g, and 27.1 (26.1, 28.1) weeks and 920 (236) g for pre- and post-cohorts, respectively. Pre-cohort had higher C-section rates, (67% vs. 51%, p = 0.03). After adjustment for covariates, LISA was associated with reduced IMV exposure [AOR (95% CI) 0.07 (0.04, 0.11)], lower odds of the composite clinical outcome [0.49 (0.33, 0.73)], and most of its individual components.

CONCLUSION

Real-world experience favors LISA as the primary method in extremely preterm infants with established spontaneous respiration.

IMPACT

Less invasive surfactant administration (LISA) is associated with a reduction in respiratory morbidity, but real-world data of routine use among extremely preterm infants are limited. LISA is associated with reduced frequency of exposure to and duration of IMV in both ≤72 h after birth and during hospital stay. LISA is associated with a reduction in mortality, and most other major morbidities including bronchopulmonary dysplasia, and interventricular hemorrhage. Data from a large North American center providing real-world clinical outcomes following LISA as the primary method of surfactant administration.

European Consensus Guidelines on the Management of Respiratory Distress Syndrome: 2022 Update

Respiratory distress syndrome (RDS) care pathways evolve slowly as new evidence emerges. We report the sixth version of "European Guidelines for the Management of RDS" by a panel of experienced European neonatologists and an expert perinatal obstetrician based on available literature up to end of 2022. Optimising outcome for babies with RDS includes prediction of risk of preterm delivery, appropriate maternal transfer to a perinatal centre, and appropriate and timely use of antenatal steroids. Evidence-based lung-protective management includes initiation of non-invasive respiratory support from birth, judicious use of oxygen, early surfactant administration, caffeine therapy, and avoidance of intubation and mechanical ventilation where possible. Methods of ongoing non-invasive respiratory support have been further refined and may help reduce chronic lung disease. As technology for delivering mechanical ventilation improves, the risk of causing lung injury should decrease, although minimising time spent on mechanical ventilation by targeted use of postnatal corticosteroids remains essential. The general care of infants with RDS is also reviewed, including emphasis on appropriate cardiovascular support and judicious use of antibiotics as being important determinants of best outcome. We would like to dedicate this guideline to the memory of Professor Henry Halliday who died on November 12, 2022.These updated guidelines contain evidence from recent Cochrane reviews and medical literature since 2019. Strength of evidence supporting recommendations has been evaluated using the GRADE system. There are changes to some of the previous recommendations as well as some changes to the strength of evidence supporting recommendations that have not changed. This guideline has been endorsed by the European Society for Paediatric Research (ESPR) and the Union of European Neonatal and Perinatal Societies (UENPS).

Circular RNAs expression profiles and bioinformatics analysis in bronchopulmonary dysplasia

BACKGROUND

Bronchopulmonary dysplasia (BPD) has long been considered the most challenging chronic lung disease for neonatologists and researchers due to its complex pathological mechanisms and difficulty in prediction. Growing evidence indicates that BPD is associated with the dysregulation of circular RNAs (circRNAs). Therefore, we aimed to explore the expression profiles of circRNAs and investigate the underlying molecular network associated with BPD.

METHODS

Peripheral blood was collected from very-low-birth-weight (VLBW) infants at 5-8 days of life to extract PBMCs. Microarray analysis and qRT-PCR tests were performed to determine the differentially expressed circRNAs (DEcircRNAs) between BPD and non-BPD VLBW infants. Simultaneous analysis of GSE32472 was conducted to obtain differentially expressed mRNAs (DEmRNA) from BPD infants. The miRNAs were predicted by DEcircRNAs and DEmRNAs of upregulated, respectively, and then screened for overlapping ones. GO and KEGG analysis was performed following construction of the competing endogenous RNA regulatory network (ceRNA) for further investigation.

RESULTS

A total of 65 circRNAs (52 upregulated and 13 downregulated) were identified as DEcircRNAs between the two groups (FC >2.0 and p.adj <0.05). As a result, the ceRNA network was constructed based on three upregulated DEcircRNAs validated by qRT-PCR (hsa_circ_0007054, hsa_circ_0057950, and hsa_circ_0120151). Bioinformatics analysis indicated these DEcircRNAs participated in response to stimulus, IL-1 receptor activation, neutrophil activation, and metabolic pathways.

CONCLUSIONS

In VLBW infants with a high risk for developing BPD, the circRNA expression profiles in PBMCs were significantly altered in the early post-birth period, suggesting immune dysregulation caused by infection and inflammatory response already existed.

Non-invasive ventilatory support in neonates: An evidence-based update

Non-invasive ventilatory support (NIV) is considered the gold standard in the care of preterm infants with respiratory distress syndrome (RDS). NIV from birth is superior to mechanical ventilation (MV) for the prevention of death or bronchopulmonary dysplasia (BPD), with a number needed to treat between 25 and 35. Various methods of NIV are available, some of them extensively researched and with well proven efficacy, whilst others are needing further research. Nasal continuous positive airway pressure (nCPAP) has replaced routine invasive mechanical ventilation (MV) for the initial stabilization and the treatment of RDS. Choosing the most suitable form of NIV and the most appropriate patient interface depends on several factors, including gestational age, underlying lung pathophysiology and the local facilities. In this review, we present the currently available evidence on NIV as primary ventilatory support to preventing intubation and for secondary ventilatory support, following extubation. We review nCPAP, nasal high-flow cannula, nasal intermittent positive airway pressure ventilation, bi-level positive airway pressure, nasal high-frequency oscillatory ventilation and nasal neurally adjusted ventilatory assist modes. We also discuss most suitable NIV devices and patient interfaces during resuscitation of the newborn in the delivery room.

A comparison of the effect of bi-level positive airway pressure and synchronized intermittent mandatory ventilation in preterm infants with respiratory distress syndrome

OBJECTIVE

Bi-level positive airway pressure (BiPAP) and synchronized intermittent mandatory ventilation (SIMV) can be used to achieve peak inspiratory pressure and positive end-expiratory pressure to avoid alveolar collapse and improve oxygenation in preterm infants during the treatment of respiratory distress syndrome (RDS), and there is an urgent demand for evaluating the effects and prognoses of these two ventilation modes.

STUDY DESIGN

We conducted a retrospective study on preterm infants (≤32 weeks and <2500 g) from March 2015 to March 2020 with BiPAP (n = 63) and SIMV (n = 63). The primary outcomes were successful treatment and weaning within 72 h, the demand for a second pulmonary surfactant supply and the need for a second respiratory support. The secondary outcome was the incidence of complications.

RESULTS

There were no significant differences (p > .05) in the primary outcomes or the incidence of complications (pneumonia, apnea, respiratory failure, air leak syndrome, persistence of patent ductus arteriosus, neonatal sepsis, necrotizing enterocolitis, retinopathy of prematurity, and intraventricular hemorrhage). There were significant differences (p < .05) in the incidence of pulmonary hemorrhage, bronchopulmonary dysplasia and IVH (≥grade II).

CONCLUSIONS

Although both BiPAP and SIMV achieved good early treatment outcomes of RDS in preterm infants, BiPAP support is recommended for reducing the incidence of pulmonary hemorrhage, bronchopulmonary dysplasia and IVH (≥grade II) if infants are tolerant. Attempts should be made to prevent these complications from happening with the use of SIMV support if infants are intolerant.

Do newborn infants exhale through the CPAP system? Secondary analysis of a randomised cross-over trial

BACKGROUND

During nasal continuous positive airway pressure (nCPAP) treatment in neonates, leakage is inevitable and can lead to reduced distending pressure in the lungs of the infant. In current practice, neither leakage nor expiratory flow is measured, which makes it difficult to assess if exhalation is through the device or entirely through leakages.

OBJECTIVE

To examine if infants treated with nCPAP exhale through the CPAP system.

DESIGN AND SETTING

Secondary data analyses from the ToNIL trial on leakages during nCPAP treatment. We retrospectively examined respiratory curves for the 50 infants included in the trial, using NI LabVIEW 2015. Each infant was measured with both prongs and nasal masks. A flow recording was classified as exhalation through the system if more than 50% of all expirations showed reverse flow, each for a minimum duration of 0.1 s.

PATIENTS

50 infants were included, born with a mean gestational age (GA) of 34 weeks, median birth weight of 1948 g and mean age at measurement 6.5 days. Inclusion criteria were CPAP treatment and a postmenstrual age (PMA) of 28-42 weeks.

RESULTS

In our measurements, 32/50 infants exhaled through the CPAP system in at least one recording with either nasal mask or prongs. Leakages exceeding 0.3 L/min were seen in 97/100 recordings.

CONCLUSIONS

During nCPAP treatment, infants can exhale through the CPAP system and leakage was common. Measuring expiratory flows and leakages in clinical settings could be valuable in optimising CPAP treatment of infants.

TRIAL REGISTRATION NUMBER

NCT03586856.

Prioritizing Health Care Strategies to Reduce Childhood Mortality

IMPORTANCE

Although child mortality trends have decreased worldwide, deaths among children younger than 5 years of age remain high and disproportionately circumscribed to sub-Saharan Africa and Southern Asia. Tailored and innovative approaches are needed to increase access, coverage, and quality of child health care services to reduce mortality, but an understanding of health system deficiencies that may have the greatest impact on mortality among children younger than 5 years is lacking.

OBJECTIVE

To investigate which health care and public health improvements could have prevented the most stillbirths and deaths in children younger than 5 years using data from the Child Health and Mortality Prevention Surveillance (CHAMPS) network.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study used longitudinal, population-based, and mortality surveillance data collected by CHAMPS to understand preventable causes of death. Overall, 3390 eligible deaths across all 7 CHAMPS sites (Bangladesh, Ethiopia, Kenya, Mali, Mozambique, Sierra Leone, and South Africa) between December 9, 2016, and December 31, 2021 (1190 stillbirths, 1340 neonatal deaths, 860 infant and child deaths), were included. Deaths were investigated using minimally invasive tissue sampling (MITS), a postmortem approach using biopsy needles for sampling key organs and fluids.

MAIN OUTCOMES AND MEASURES

For each death, an expert multidisciplinary panel reviewed case data to determine the plausible pathway and causes of death. If the death was deemed preventable, the panel identified which of 10 predetermined health system gaps could have prevented the death. The health system improvements that could have prevented the most deaths were evaluated for each age group: stillbirths, neonatal deaths (aged <28 days), and infant and child deaths (aged 1 month to <5 years).

RESULTS

Of 3390 deaths, 1505 (44.4%) were female and 1880 (55.5%) were male; sex was not recorded for 5 deaths. Of all deaths, 3045 (89.8%) occurred in a healthcare facility and 344 (11.9%) in the community. Overall, 2607 (76.9%) were deemed potentially preventable: 883 of 1190 stillbirths (74.2%), 1010 of 1340 neonatal deaths (75.4%), and 714 of 860 infant and child deaths (83.0%). Recommended measures to prevent deaths were improvements in antenatal and obstetric care (recommended for 588 of 1190 stillbirths [49.4%], 496 of 1340 neonatal deaths [37.0%]), clinical management and quality of care (stillbirths, 280 [23.5%]; neonates, 498 [37.2%]; infants and children, 393 of 860 [45.7%]), health-seeking behavior (infants and children, 237 [27.6%]), and health education (infants and children, 262 [30.5%]).

CONCLUSIONS AND RELEVANCE

In this cross-sectional study, interventions prioritizing antenatal, intrapartum, and postnatal care could have prevented the most deaths among children younger than 5 years because 75% of deaths among children younger than 5 were stillbirths and neonatal deaths. Measures to reduce mortality in this population should prioritize improving existing systems, such as better access to antenatal care, implementation of standardized clinical protocols, and public education campaigns.

Identifying the essential knowledge and skills for Neonatal-Perinatal Medicine: a systematic analysis of practice

The knowledge and skills expected for board certification in Neonatal-Perinatal Medicine (NPM) should reflect the clinical practice of neonatology. First, a 14-member panel of practicing neonatologists, convened by the American Board of Pediatrics (ABP), drafted a practice analysis document which identified the practice domains, tasks, knowledge, and skills deemed essential for clinical practice. NPM fellowship program directors provided feedback via online survey resulting in revisions to the document. During the second phase of the project, the panel organized testable knowledge areas into content domains and subdomains to update the existing ABP NPM content outline. All ABP board-certified neonatologists were asked to review via online survey, and results were used to guide final revisions to the content outline. The NPM practice analysis document and the updated NPM content outline should serve as helpful resources for educators, trainees, and practicing neonatologists.

Clinical Evaluation of an Automatic Oxygen Control System for Premature Infants Receiving High-Flow Nasal Cannula for Respiratory Support: A Pilot Study

A pilot clinical study was conducted that compared the peripheral oxygen saturation (SpO2) targeting performance of an automatic oxygen control system with manual oxygen control, which is the standard of care for preterm and low birth weight infants on high-flow nasal cannula (HFNC). The new oxygen control device studied was used to automatically adjust the fraction of inspired oxygen (FiO2) according to a desired SpO2 target setpoint and measured feedback signals including the SpO2 and other signals. A crossover study was designed with several endpoints including the comparison of the percentage of time that the SpO2 was within the target range with the automatic oxygen control device versus manual oxygen control. Other metrics were also compared to assess the performance of the system including the number of bradycardia events. The pilot study included six patients that fit the inclusion criteria. The results showed that there were improvements in all of the measured outcomes considered including statistically significant improvements in the number of bradycardia events during the period when the automatic oxygen control device was used.

Impact of Kangaroo Mother Care Intervention on Immunological and Pulmonary Functions of Preterm Infants during Breastfeeding

Objective

Preterm infants (PTIs) are prone to respiratory failure or other diseases due to immature organ development and poor immunological function. Herein, the effects of Kangaroo Mother Care (KMC) on the immunological and pulmonary functions of PTIs during breastfeeding were investigated in this study.

Methods

The study recruited 86 delivery women and their PTIs with preterm pregnancy outcomes, consisting of 46 cases receiving breastfeeding plus KMC intervention (KMC group) and 40 cases receiving breastfeeding plus routine care (control group). The time of first lactation, time of first breastfeeding, and duration of first breastfeeding were observed in both cohorts. The breastfeeding status was assessed using the LATCH system. Maternal psychological status was evaluated by the breastfeeding self-efficacy scale (BSES) and self-rating anxiety/depression scale (SAS/SDS). The growth and development of PTIs were recorded, and the levels of postalbumin (PA), transferrin (TRF), plasma albumin (ALB), immunoglobulin (Ig) A, IgG, IgM, and complement C3 and C4 were measured. The tidal volume (VT), tidal volume per kilogram (VT/kg), minute volume (MV), and minute volume per kilogram (MV/kg) were detected using a pulmonary function tester.

Results

The KMC group presented shorter time of first lactation and first breastfeeding than the control group, with longer duration of first breastfeeding (P < 0.05). After intervention, the BSES scores of delivery women were increased, while the SAS and SDS scores were decreased, with more notable improvements in the KMC group (P < 0.05). The levels of PA, TRF, ALB, IgA, IgG, VT, and MV were elevated in PTIs in both groups, with more evident increase in the KMC group than in the control group (P < 0.05). A better growth of PTIs was found in the KMC group than the control group (P < 0.05).

Conclusions

The study demonstrated that KMC intervention during breastfeeding could benefit PTIs specifically regarding their immunological and pulmonary functions.

Neonatal Preterm Respiratory Care in Ukraine: An Observational Study of Outcomes in Relation to Timing and Methods of Surfactant Treatment

OBJECTIVE

Timely and effective noninvasive respiratory support and surfactant administration are the key determinants of clinical outcomes in very preterm infants. The objective of this study was to evaluate the impact of the changes in clinical practice of surfactant administration on clinical outcomes and the incidence of continuous positive airway pressure (CPAP) failure defined as the need for mechanical ventilation (MV) during the first 5 days of life in preterm infants <32 weeks.

STUDY DESIGN

One hundred sixty-five outborn very preterm infants with respiratory distress syndrome (RDS), initially managed on CPAP, were enrolled in a retrospective cohort study. Fifty-two infants treated with surfactant using less invasive or INSURE technique were included in the surfactant group. One hundred thirteen control infants received surfactant only in case of CPAP failure.

RESULTS

The study groups were similar in gestational age, rates of main obstetric complications, and antenatal steroid prophylaxis. The rate of cesarean delivery was significantly higher but birth weight and need for resuscitation were lower in infants from the surfactant group. Fifty-five infants with CPAP failure (49%) received surfactant after initiation of MV in the control group in comparison with 52 (100%) in the surfactant group (p < 0.001). The incidence of CPAP failure was significantly higher in the control group (49 vs. 27%; p < 0.01) and it occurred earlier (median [interquartile range age: 4 [2-5] vs. 47 [36-99] hours, respectively; p < 0.001). Early surfactant administration significantly and independently affected the probability of CPAP failure (adjusted odds ratio: 0.29, 95% confidence interval: 0.13-0.67; p < 0.01). There were no differences in morbidities between the groups, but CPAP failure was significantly associated with higher morbidity and mortality.

CONCLUSION

Adherence to the European RDS guidelines with early rescue, less invasive surfactant administration in very preterm infants decreased the probability of CPAP failure which was significantly associated with higher morbidity and mortality.

KEY POINTS

· Early surfactant decreases the probability of CPAP failure.. · Timing and methods of surfactant administration are important.. · Randomized comparisons of prophylactic LISA and CPAP are needed..

Ultrasound-guided caudal blockade and sedation for paediatric surgery: a retrospective cohort study

Data on safety and success rates of ultrasound‐guided caudal blockade, performed on sedated children with an uninstrumented airway, are scarce. We performed a retrospective observational study of validated data from April 2014 to December 2020 in a paediatric cohort where the initial plan for anaesthetic management was sedation and caudal epidural without general anaesthesia or airway instrumentation. We examined success rates of this approach and rates of block failure and block‐related complications. In total, 2547 patients ≤ 15 years of chronological age met inclusion criteria. Among the 2547 cases, including 453 (17.8%) former preterm patients, caudal‐plus‐sedation success rate was 95.1%. The primary anaesthesia plan was abandoned for general anaesthesia in 124 cases. Pain‐related block failure in 83 (3.2%) was the most common cause for conversion. Complications included 39 respiratory events and 9 accidental spinal anaesthetics. Higher odds of pain‐related block failure were associated with higher body weight (adjusted OR 1.063, 95%CI 1.035–1.092, p < 0.001) as well as with mid‐abdominal surgery (e.g. umbilical hernia repair) (adjusted OR 15.11, 95%CI 7.69–29.7, p < 0.001), whereas extreme (< 28 weeks) former prematurity, regardless of chronological age, was associated with higher odds (adjusted OR 3.62, 95%CI 1.38–9.5, p = 0.009) for respiratory problems. Ultrasound‐guided caudal epidural, performed under sedation with an uninstrumented airway, is an effective technique in the daily clinical routine. Higher body weight and mid‐abdominal surgical procedures are risk factors for pain‐related block failure. Patients who, regardless of chronological age, had been born as extreme preterm babies are at the highest risk for respiratory events.

Tracking of lung function from 10 to 35 years after being born extremely preterm or with extremely low birth weight

Background

Lifelong pulmonary consequences of being born extremely preterm or with extremely low birth weight remain unknown. We aimed to describe lung function trajectories from 10 to 35 years of age for individuals born extremely preterm, and address potential cohort effects over a period that encompassed major changes in perinatal care.

Methods

We performed repeated spirometry in three population-based cohorts born at gestational age ≤28 weeks or with birth weight ≤1000 g during 1982–85, 1991–92 and 1999–2000, referred to as extremely preterm-born, and in term-born controls matched for age and gender. Examinations were performed at 10, 18, 25 and 35 years. Longitudinal data were analysed using mixed models regression, with the extremely preterm-born stratified by bronchopulmonary dysplasia (BPD).

Results

We recruited 148/174 (85%) eligible extremely preterm-born and 138 term-born. Compared with term-born, the extremely preterm-born had lower z-scores for forced expiratory volume in 1 s (FEV₁) at most assessments, the main exceptions were in the groups without BPD in the two youngest cohorts. FEV₁ trajectories were largely parallel for the extremely preterm- and term-born, also during the period 25–35 years that includes the onset of the age-related decline in lung function. Extremely preterm-born had lower peak lung function than term-born, but z-FEV₁ values improved for each consecutive decade of birth (p=0.009). More extremely preterm—than term-born fulfilled the spirometry criteria for chronic obstructive pulmonary disease, 44/148 (30%) vs 7/138 (5%), p<0.001.

Conclusions

Lung function after extremely preterm birth tracked in parallel, but significantly below the trajectories of term-born from 10 to 35 years, including the incipient age-related decline from 25 to 35 years. The deficits versus term-born decreased with each decade of birth from 1980 to 2000.

Excess risk of subsequent infection in hospitalized children from a community cohort study in Cambodia and Madagascar

BACKGROUND

Children in low- and middle-income countries are particularly vulnerable in the months following an initial health event (IHE), with increased risk of mortality caused mostly by infectious diseases. Due to exposure to a wide range of environmental stressors, hospitalization in itself might increase child vulnerability at discharge. The goal of this study was to disentangle the role of hospitalization on the risk of subsequent infection.

METHODS

Data from a prospective, longitudinal, international, multicenter mother-and-child cohort were analysed. The main outcome assessed was the risk of subsequent infection within 3 months of initial care at hospital or primary healthcare facilities. First, risk factors for being hospitalized for the IHE (Step 1) and for having a subsequent infection (Step 2) were identified. Then, inpatients were matched with outpatients using propensity scores, considering the risk factors identified in Step 1. Finally, adjusted on the risk factors identified in Step 2, Cox regression models were performed on the matched data set to estimate the effect of hospitalization at the IHE on the risk of subsequent infection.

RESULTS

Among the 1312 children presenting an IHE, 210 (16%) had a subsequent infection, mainly lower-respiratory infections. Although hospitalization did not increase the risk of subsequent diarrhoea or unspecified sepsis, inpatients were 1.7 (95% Confidence Intervals [1.0-2.8]) times more likely to develop a subsequent lower-respiratory infection than comparable outpatients.

CONCLUSION

For the first time, our findings suggest that hospitalization might increase the risk of subsequent lower-respiratory infection adjusted on severity and symptoms at IHE. This highlights the need for robust longitudinal follow-up of at-risk children and the importance of investigating underlying mechanisms driving vulnerability to infection.

Risk factors and bronchopulmonary dysplasia severity: data from the Spanish Bronchopulmonary Dysplasia Research Network

GEIDIS is a national-based research-net registry of patients with bronchopulmonary dysplasia (BPD) from public and private Spanish hospitals. It was created to provide data on the clinical characterization and follow-up of infants with BPD until adulthood. The purpose of this observational study was to analyze the characteristics and the impact of perinatal risk factors on BPD severity. The study included 1755 preterm patients diagnosed with BPD. Of the total sample, 90.6% (n = 1591) were less than 30 weeks of gestation. The median gestational age was 27.1 weeks (25.8-28.5) and median birth weight 885 g (740-1,070 g). A total of 52.5% (n = 922) were classified as mild (type 1), 25.3% (n = 444) were moderate (type 2), and 22.2% (n = 389) were severe BPD (type 3). In patients born at under 30 weeks' gestation, most pre-and postnatal risk factors for type 2/3 BPD were associated with the length of exposure to mechanical ventilation (MV). Independent prenatal risk factors were male gender, oligohydramnios, and intrauterine growth restriction. Postnatal risk factors included the need for FiO2 of > 0.30 in the delivery room, nosocomial pneumonia, and the length of exposure to MV. Conclusion: In this national-based research-net registry of BPD patients, the length of MV is the most important risk factor associated with type 2/3 BPD. Among type 3 BPD patients, those who required an FiO2 > .30 at 36 weeks' postmenstrual age had a higher morbidity, during hospitalization and at discharge, compared to those with nasal positive pressure but FiO2 < .30. What is Known: • BPD is a highly complex multifactorial disease associated with preterm birth. What is New: • The length of exposure to mechanical ventilation is the most important postnatal risk factor associated to bronchopulmonary severity which modulate the effect of most pre and postnatal risk factors. • Among patients with BPD, the requirement for FiO2 >.30% at 36 weeks of postmenstrual age is associated with greater morbidity during hospitalization and at discharge.

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

INTRODUCTION

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

DESIGN

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

RESULTS

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

DISCUSSION

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

Synchronized Invasive Mechanical Ventilation

Respiratory care of premature neonates has witnessed substantial advances in the last two decades and has played a crucial role in decreasing early mortality in this population. This review outlines advances in techniques of synchronization and modes of synchronized invasive mechanical ventilation in neonates. The use of synchronized ventilation in the neonatal population was delayed as compared to adults, mainly because of technical reasons. Coordinating the infant's respiratory effort and the onset of mechanical ventilation in the neonatal population has requested high sensitivity instruments.

Deferred Consent in Neonatal Clinical Research: Why, When, How?

Deferred consent has gained traction in some countries as a possible adjunct to prospective consent for evaluating emergency therapies in the neonatal population. This form of consent has been shown to increase recruitment of acutely and critically unwell patients, potentially reduce parent decision-making burden, and provide more robust evidence for clinical treatments where equipoise exists. However, deferred consent raises complex ethical concerns and guidelines for its use vary across different jurisdictions. The views of all stakeholders, including neonatal providers and parents, are important in determining the appropriateness of deferred consent in high-risk patients. Deferred consent may be ethically justifiable for assessing various treatments, particularly those used in emergency medical management. We present a framework based on neonatal deferred consent trials that assess both non-drug and drug interventions, our experience conducting deferred consent neonatal studies in Australia, and the views of providers and parents on how to best implement deferred consent in the neonatal research setting.