Sustained Lung Inflations During Neonatal Resuscitation at Birth: A Meta-analysis

Impact of neonatal noninvasive resuscitation strategies on lung mechanics, tracheal pressure, and tidal volume in preterm lambs

This study investigated the relationship between three respiratory support approaches on lung volume recruitment during the first 2 h of postnatal life in preterm lambs. We estimated changes in lung aeration, measuring respiratory resistance and reactance by oscillometry at 5 Hz. We also measured intratracheal pressure in subsets of lambs. The first main finding is that sustained inflation (SI) applied noninvasively (Mask SI; n = 7) or invasively [endotracheal tube (ETT) SI; n = 6] led to similar rapid lung volume recruitment (∼6 min). In contrast, Mask continuous positive airway pressure (CPAP) without SI (n = 6) resuscitation took longer (∼30-45 min) to reach similar lung volume recruitment. The second main finding is that, in the first 15 min of postnatal life, the Mask CPAP without SI group closed their larynx during custom ventilator-driven expiration, leading to intratracheal positive end-expiratory pressure of ∼17 cmH2O (instead of 8 cmH2O provided by the ventilator). In contrast, the Mask SI group used the larynx to limit inspiratory pressure to ∼26 cmH2O (instead of 30 cmH2O provided by the ventilator). These different responses affected tidal volume, being larger in the Mask CPAP without SI group [8.4 mL/kg; 6.7-9.3 interquartile range (IQR)] compared to the Mask SI (5.0 mL/kg; 4.4-5.2 IQR) and ETT SI groups (3.3 mL/kg; 2.6-3.7 IQR). Distinct physiological responses suggest that spontaneous respiratory activity of the larynx of preterm lambs at birth can uncouple pressure applied by the ventilator to that applied to the lung, leading to unpredictable lung pressure and tidal volume delivery independently from the ventilator settings.NEW & NOTEWORTHY We compared invasive and noninvasive resuscitation on lambs at birth, including or not sustained inflation (SI). Lung volume recruitment was faster in those receiving SI. During noninvasive resuscitation, larynx modulation reduced tracheal pressure from that applied to the mask in lambs receiving SI, while it led to increased auto-positive end-expiratory pressure and very large tidal volumes in lambs not receiving SI. Our results highlight the need for individualizing pressures and monitoring tidal volumes during resuscitation at birth.

Blinding Assessments in Neonatal Ventilation Meta-Analyses: A Systematic Meta-Epidemiological Review

INTRODUCTION

Randomization and blinding are generally important in randomized trials. In neonatology, blinding of ventilation strategies is unfeasible if not impossible and we hypothesized that its importance has been overestimated, while the peculiarities of the neonatal patient and the specific outcomes have not been considered.

METHODS

For this meta-epidemiological review, we searched PubMed and Scopus databases in November 2023. We included all meta-analyses focusing on ventilation, published in past 5 years, and reporting either mortality or bronchopulmonary dysplasia (BPD) as an outcome. We extracted the information about how the authors had analyzed risk of bias and evidence certainty.

RESULTS

We screened 494 abstracts and included 40 meta-analyses. Overall, 13 of the 40 reviews assessed blinding properly. Australian and European authors were most likely to perform correct assessment of the blinding (p = 0.03) and the use of RoB 2.0 tool was also associated with proper assessment (p < 0.001). In multivariate regression, the use of RoB 2.0 was the only factor associated with a proper assessment (Beta 0.57 [95% confidence interval: 0.29-0.99]). GRADE ratings were performed in 25 reviews, and the authors downgraded the evidence certainty due to risk of bias in 19 of these and none of these reviews performed the blinding assessment correctly.

CONCLUSION

In past neonatal evidence syntheses, the role of blinding has been mostly overestimated, which has led to downgrading of evidence certainty. Objective outcomes (such as mortality and BPD) do not need to be downgraded due to lack of blinding, as the knowledge of the received intervention does not influence the outcome assessment.

Preterm lung and brain responses to mechanical ventilation and corticosteroids

Mechanical ventilation is necessary to maintain oxygenation and ventilation in many preterm infants. Unfortunately, even short periods of mechanical ventilation can cause lung and airway injury, and initiate the lung inflammation that contributes to the development of bronchopulmonary dysplasia (BPD). The mechanical stretch leads to airway cell differentiation and simplification of the alveoli, and releases cytokines that cause systemic response in other organs. Mechanical ventilation also leads to brain injury (IVH, white and gray matter) and neuronal inflammation that can affect the neurodevelopment of preterm infants. In efforts to decrease BPD, corticosteroids have been used for both prevention and treatment of lung inflammation. Corticosteroids have also been demonstrated to cause neuronal injury, so the clinician must balance the negative effects of both mechanical ventilation and steroids on the brain and lungs. Predictive models for BPD can help assess the infants who will benefit most from corticosteroid exposure. This review describes the lung and brain injury from mechanical ventilation in the delivery room and chronic mechanical ventilation in animal models. It provides updates on the current guidelines for use of postnatal corticosteroids (dexamethasone, hydrocortisone, budesonide, budesonide with surfactant) for the prevention and treatment of BPD, and the effects the timing of each steroid regimen has on neurodevelopment.

Ventilation devices for neonatal resuscitation at birth: A systematic review and meta-analysis

Initial management of inadequate adaptation to extrauterine life relies on non-invasive respiratory support. Two types of devices are available: fixed pressure devices (FPD; T-pieces or ventilators) and hand driven pressure devices (HDPD; self- or flow-inflating bags). This systematic review and meta-analysis aims to compare clinical outcomes after neonatal resuscitation according to device type.

METHODS

Four databases were searched from inception to 2022, January. Search strategies included Mesh/Emtree terms as well as free language without any restriction. Randomized, quasi-randomized studies and prospective cohorts comparing the use of the two types of devices in neonatal resuscitation were included.

RESULTS

Nine studies recruiting 3621 newborns were included: 5 RCTs, 2 RCTs with interventions bundles and 2 prospective cohorts. Meta-analysis of the 5 RCTs demonstrated significant reductions in bronchopulmonary dysplasia (RR0,68[0,48-0,96]-NNT 31) and other respiratory outcomes: intubation in the delivery room (RR0,72[0,58-0,88]-NNT 13,4), mechanical ventilation requirements (RR0,81[0,67-0,96]-NNT 17) and duration (MD-1,54 days[-3,03- -0,05]), need for surfactant (RR0,79[0,64-0,96]-NNT 7,3). The overall analysis found a lower mortality in the FPD group (OR0,57[0,47-0,69]-NNT 12,7) and confirmed decreases in intubation, surfactant requirement and mechanical ventilation rates (OR 0,56[0,40-0,79]- NNT7,5; OR 0,67[0,55-0,82]-NNT10,7 and OR0,58[0,42-0,80]- NNT 7,4 respectively). The risk of cystic periventricular leukomalacia (cPVL) decreased significantly with FPD (OR0.59[0.41-0.85]-NNT 27). Pneumothorax rates were similar (OR0.82[0.44-1.52]).

CONCLUSION AND RELEVANCE

Resuscitation at birth with FPD improves respiratory transition and decreases BPD with a very low to moderate certainty of evidence. There is suggestion of decreases in mortality and cPVL. Further studies are still needed to confirm those results.

Positive pressure ventilation at birth

OBJECTIVE

To review the current state of the art of positive pressure ventilation (PPV) during resuscitation FINDINGS: The frequency of PPV during delivery room resuscitation varies across settings and gestational age subgroups. Goal targets and parameters for delivery room PPV remain undefined. The T-piece resuscitator provides the most consistent pressures during PPV and may improve clinical outcomes. The laryngeal mask may be an important alternative interface for PPV, but more data are needed to identify the optimal role of the supraglottic airway during PPV. No objective monitors of PPV have conclusively demonstrated improved outcomes to date.

CONCLUSION

More information, including real-world data from population-based studies, is needed to provide data-driven guidelines for positive pressure ventilation during neonatal transition after birth.

Recent Update on Neonatal Resuscitation

Every 5 y, the International Liaison Committee on Resuscitation publishes consensus on cardiopulmonary resuscitation, and emergency cardiovascular science and treatment recommendations. The latest update on neonatal resuscitation guidelines was published in 2020. Here, the authors review the important changes in the recent recommendations, including initial steps of resuscitation, umbilical cord management, management of nonvigorous infants born through meconium-stained amniotic fluid, sustained inflation in preterm infants, epinephrine, vascular access, timing of discontinuation of resuscitative effort, and team briefing and debriefing.

Resuscitation 2020: Proceedings From the NeoHeart 2020 International Conference

Resuscitation guidelines are developed and revised by medical societies throughout the world. These guidelines are increasingly based on evidence from preclinical and clinical research. The International Liaison Committee on Resuscitation reviews evidence for each resuscitation practice and provides summary consensus statements that inform resuscitation guideline committees. A similar process is used for different populations including neonatal, pediatric, and adult resuscitation. The NeoHeart 2020 Conference brought together experts in resuscitation to discuss recent evidence and guidelines for resuscitation practices. This review summarizes the main focus of discussion from this symposium.

Delivery Room Care for Premature Infants Born after Less than 25 Weeks' Gestation-A Narrative Review

Premature infants born after less than 25 weeks' gestation are particularly vulnerable at birth and stabilization in the delivery room (DR) is challenging. After birth, infants born after <25 weeks' gestation develop respiratory and hemodynamic instability due to their immature physiology and anatomy. Successful stabilization at birth has the potential to reduce morbidities and mortalities, while suboptimal DR care could increase long-term sequelae. This article reviews current neonatal resuscitation guidelines and addresses challenges during DR stabilization in extremely premature infants born after <25 weeks' gestation at the threshold of viability.

A comparative evaluation and appraisal of 2020 American Heart Association and 2021 European Resuscitation Council neonatal resuscitation guidelines

AIM

The International Liaison Committee on Resuscitation (ILCOR) 2020 Consensus on Science and Treatment Recommendations (CoSTR) for Neonatal Life Support forms the basis for guidelines developed by regional councils such as the American Heart Association (AHA) and the European Resuscitation Council (ERC). We aimed to determine if the updated guidelines are congruent, identify the source of variation, and score their quality.

METHODS

We compared the approach to developing recommendations, final recommendations, and cited evidence in the AHA 2020 and ERC 2021 neonatal resuscitation guidelines. Two investigators scored guideline quality using the Appraisal of Guidelines for Research and Evaluation II (AGREE II) tool.

RESULTS

Differences in the recommendations were found between AHA 2020 and ERC 2021 neonatal resuscitation guidelines. The councils gave differing recommendations for practices that had sparse evidence and made recommendations based on expert consensus or observational studies. AGREE II assessment revealed that AHA scored better for the domain 'rigour of development', but ERC had a higher score for 'stakeholder involvement'. Both AHA and ERC scored relatively less for 'applicability'.

CONCLUSION

AHA and ERC guidelines are predominantly based on the ILCOR CoSTR. Differences in recommendations between the two were largely related to the evidence gathering process for questions not reviewed by ILCOR, paucity of evidence for some recommendations based on existing regional practices and supported by expert opinion, and different interpretation or application of same evidence. Overall, both guidelines scored well on the AGREE II assessment, but each had domains that could be improved in future editions.

Singapore Neonatal Resuscitation Guidelines 2021

Neonatal resuscitation is a coordinated, team-based series of timed sequential steps that focuses on a transitional physiology to improve perinatal and neonatal outcomes. The practice of neonatal resuscitation has evolved over time and continues to be shaped by emerging evidence as well as key opinions. We present the revised Neonatal Resuscitation Guidelines for Singapore 2021. The recommendations from the International Liaison Committee on Resuscitation Neonatal Task Force Consensus on Science and Treatment Recommendations (2020) and guidelines from the American Heart Association and European Resuscitation Council were compared with existing guidelines. The recommendations of the Neonatal Subgroup of the Singapore Resuscitation and First Aid Council were derived after the work group discussed and appraised the current available evidence and their applicability to local clinical practice.

Is Chest Compression Superimposed with Sustained Inflation during Cardiopulmonary Resuscitation an Alternative to 3:1 Compression to Ventilation Ratio in Newborn Infants?

Approximately 0.1% for term and 10-15% of preterm infants receive chest compression (CC) in the delivery room, with high incidence of mortality and neurologic impairment. The poor prognosis associated with receiving CC in the delivery room has raised concerns as to whether specifically-tailored cardiopulmonary resuscitation methods are needed. The current neonatal resuscitation guidelines recommend a 3:1 compression:ventilation ratio; however, the most effective approach to deliver chest compression is unknown. We recently demonstrated that providing continuous chest compression superimposed with a high distending pressure or sustained inflation significantly reduced time to return of spontaneous circulation and mortality while improving respiratory and cardiovascular parameters in asphyxiated piglet and newborn infants. This review summarizes the current available evidence of continuous chest compression superimposed with a sustained inflation.