From liquid to air: breathing after birth

Delivery Room Lung Ultrasound-Feasibility, Normal Patterns, and Predictive Value for Respiratory Support in Term and Near-Term Neonates: A Monocentric Study

AIM

our study aimed to characterize the lung ultrasound (LUS) patterns noted immediately after delivery in term and near-term neonates, and to investigate whether the LUS scores or patterns observed at that point could anticipate the need for respiratory support in the sample of patients studied.

MATERIALS AND METHODS

We performed two ultrasound examinations: one in the delivery room and the second at one hour of age. The anterior and lateral regions of both lungs were examined. We assessed the correlation between the LUS scores or patterns and the gestational age, umbilical arterial blood gases, the need for respiratory support (CPAP or mechanical ventilation), the presence of respiratory distress, and the need for the administration of oxygen.

RESULTS

LUS scores were significantly higher in the delivery room examination (8.05 ± 1.95) than at 1 h of age (6.4 ± 1.75) (p < 0.001). There were also statistically significant differences between the LUS patterns observed in different lung regions between the delivery room exam and the exam performed at 1 h of age (p values between 0.001 and 0.017). There were also differences noted regarding the LUS patterns between different lung regions at the exam in the delivery room (the right anterior region LUS patterns were significantly worse than the right lateral LUS patterns (p < 0.004), left anterior LUS patterns (p < 0.001), and left lateral LUS patterns (p < 0.001)). A statistically significant correlation was found between LUS scores and the gestational age of the patients (r = 0.568, p < 0.001-delivery room; r = 4.0443, p < 0.001-one hour of age). There were statistically significant associations between LUS scores, patterns at delivery (p < 0.001) and 1 h of age (p < 0.001), and the need for respiratory support (CPAP or mechanical ventilation).

CONCLUSIONS

LUS in the delivery room offers important information regarding lung fluid elimination and aeration of the lungs, and early LUS features are significantly associated with the risk of respiratory distress and the need for respiratory support.

Transferring an extremely premature infant to an extra-uterine life support system: a prospective view on the obstetric procedure

To improve care for extremely premature infants, the development of an extrauterine environment for newborn development is being researched, known as Artificial Placenta and Artificial Womb (APAW) technology. APAW facilitates extended development in a liquid-filled incubator with oxygen and nutrient supply through an oxygenator connected to the umbilical vessels. This setup is intended to provide the optimal environment for further development, allowing further lung maturation by delaying gas exposure to oxygen. This innovative treatment necessitates interventions in obstetric procedures to transfer an infant from the native to an artificial womb, while preventing fetal-to-neonatal transition. In this narrative review we analyze relevant fetal physiology literature, provide an overview of insights from APAW studies, and identify considerations for the obstetric procedure from the native uterus to an APAW system. Lastly, this review provides suggestions to improve sterility, fetal and maternal well-being, and the prevention of neonatal transition.

The vocal cords are predominantly closed in preterm infants <30 weeks gestation during transition after birth; an observational study

AIM

Studies in animals have shown that vocal cords (VCs) close during apnoea before and after birth, thereby impairing the effect of non-invasive ventilation. We tested the feasibility of visualising VCs using ultrasonography (US) and investigated the position and movement of the VCs during non-invasive respiratory support of preterm infants at birth.

METHODS

In an observational study, VCs were visualised using US in infants <30 weeks gestation during both stabilisation after birth and at one hour after birth. Respiratory efforts were simultaneously recorded. The percentage of time the VCs were closed in the first ten minutes was determined from videoframes acquired at 15 Hz and compared with respiratory flow patterns measured using a respiratory function monitor.

RESULTS

US of the VCs could be performed in 20/20 infants included (median (IQR) gestational age 27+6 (27+1-28+6) weeks) without interfering with stabilisation, of whom 60% (12/20) were initially breathing and 40% (8/20) were apnoeic at birth. In breathing infants, the VCs closed between breaths and during breath holds, which accounted for 57% (49-66) of the time. In apnoeic infants receiving positive pressure ventilation, the VCs were closed for 93% (81-99) of the time. US at one hour after birth could be performed in 14/20 infants, VCs were closed between breaths and during breath holds, accounting for 46% (27-52) of the time.

CONCLUSION

Visualising VCs in preterm infants at birth using US is feasible. The VCs were closed during apnoea, in between breaths and during breath holds, impairing the effect of ventilation given.

Video-Recorded Airway Suctioning of Clear and Meconium-Stained Amniotic Fluid and Associated Short-Term Outcomes in Moderately and Severely Depressed Preterm and Term Infants

BACKGROUND

The aim of this study was to investigate delivery room airway suctioning and associated short-term outcomes in depressed infants.

METHODS

This is a single-centre prospective observational study of transcribed video recordings of preterm (gestational age, GA < 37 weeks) and term (GA ≥ 37 weeks) infants with a 5 min Apgar score ≤ 7. We analysed the association between airway suctioning, breathing, bradycardia and prolonged resuscitation (≥10 min). For comparison, non-suctioned infants with a 5 min Apgar score ≤ 7 were included.

RESULTS

Two hundred suction episodes were performed in 19 premature and 56 term infants. Breathing improved in 1.9% of premature and 72.1% of term infants, and remained unchanged in 84.9% of premature and 27.9% of term infants after suctioning. In our study, 61 (81.3%) preterm and term infants who were admitted to the neonatal intensive care unit experienced bradycardia after airway suctioning. However, the majority of the preterm and more than half of the term infants were bradycardic before the suction procedure was attempted. Among the non-airway suctioned infants (n = 26), 73.1% experienced bradycardia, with 17 non-airway suctioned infants being admitted to the neonatal intensive care unit. There was a need for resuscitation ≥ 10 min in 8 (42.1%) preterm and 32 (57.1%) term infants who underwent airway suctioning, compared to 2 (33.3%) preterm and 19 (95.0%) term infants who did not receive airway suctioning.

CONCLUSIONS

In the infants that underwent suctioning, breathing improved in most term, but not preterm infants. More non-suctioned term infants needed prolonged resuscitation. Airway suctioning was not directly associated with worsening of breathing, bradycardia, or extended resuscitation needs.

Fetal Pulmonary Venous Return: From Basic Research to the Clinical Value of Doppler Assessment

The fetal pulmonary circulation represents less than 25% of the fetal cardiac output. In comparison with the pulmonary arteries, studies on pulmonary veins are few and limited, and many questions remain to be answered. The literature reports that pulmonary veins play an important role in regulating vascular flow, forming an active segment of the pulmonary circulation. The development of more sophisticated ultrasonography technology has allowed the investigation of the extraparenchymal pulmonary veins and their waveform. The recognition of the pulmonary vein anatomy in echocardiography is important for the diagnosis of anomalous pulmonary venous connections, with a significant impact on prognosis. On the other hand, the identification of the normal pulmonary vein waveform seems to be a reliable way to study left heart function, with potential applicability in fetal and maternal pathology. Thus, the goal of this narrative review was to provide a clinically oriented perspective of the available literature on this topic.

The Respiratory Management of the Extreme Preterm in the Delivery Room

The fetal-to-neonatal transition poses an extraordinary challenge for extremely low birth weight (ELBW) infants, and postnatal stabilization in the delivery room (DR) remains challenging. The initiation of air respiration and the establishment of a functional residual capacity are essential and often require ventilatory support and oxygen supplementation. In recent years, there has been a tendency towards the soft-landing strategy and, subsequently, non-invasive positive pressure ventilation has been generally recommended by international guidelines as the first option for stabilizing ELBW in the delivery room. On the other hand, supplementation with oxygen is another cornerstone of the postnatal stabilization of ELBW infants. To date, the conundrum concerning the optimal initial inspired fraction of oxygen, target saturations in the first golden minutes, and oxygen titration to achieve desired stability saturation and heart rate values has not yet been solved. Moreover, the retardation of cord clamping together with the initiation of ventilation with the patent cord (physiologic-based cord clamping) have added additional complexity to this puzzle. In the present review, we critically address these relevant topics related to fetal-to-neonatal transitional respiratory physiology, ventilatory stabilization, and oxygenation of ELBW infants in the delivery room based on current evidence and the most recent guidelines for newborn stabilization.

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.

Transitional circulation and hemodynamic monitoring in newborn infants

Transitional circulation is normally transient after birth but can vary markedly between infants. It is actually in a state of transition between fetal (in utero) and neonatal (postnatal) circulation. In the absence of definitive clinical trials, information from applied physiological studies can be used to facilitate clinical decision making in the presence of hemodynamic compromise. This review summarizes the peculiar physiological features of the circulation as it transitions from one phenotype into another in term and preterm infants. The common causes of hemodynamic compromise during transition, intact umbilical cord resuscitation, and advanced hemodynamic monitoring are discussed. IMPACT: Transitional circulation can vary markedly between infants. There are alterations in preload, contractility, and afterload during the transition of circulation after birth in term and preterm infants. Hemodynamic monitoring tools and technology during neonatal transition and utilization of bedside echocardiography during the neonatal transition are increasingly recognized. Understanding the cardiovascular physiology of transition can help clinicians in making better decisions while managing infants with hemodynamic compromise. The objective assessment of cardio-respiratory transition and understanding of physiology in normal and disease states have the potential of improving short- and long-term health outcomes.

Physiology of neonatal resuscitation: Giant strides with small breaths

The transition of a fetus to a newborn involves a sequence of well-orchestrated physiological events. Most neonates go through this transition without assistance but 5-10% may require varying degrees of resuscitative interventions at birth. The most crucial event during this transition is lung inflation with optimal concentrations of oxygen. Rarely, extensive resuscitation including chest compressions and medication may be required. In the past few decades, significant strides have been made in our understanding of the cardiorespiratory transition at birth from a fetus to a newborn and the subsequent resuscitation. This article reviews the physiology behind neonatal transition at birth and various interventions during neonatal resuscitation.

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.

The Newborn's Reaction to Light as the Determinant of the Brain's Activation at Human Birth

Developmental neuroscience research has not yet fully unveiled the dynamics involved in human birth. The trigger of the first breath, often assumed to be the marker of human life, has not been characterized nor has the process entailing brain modification and activation at birth been clarified yet. To date, few researchers only have investigated the impact of the extrauterine environment, with its strong stimuli, on birth. This ‘hypothesis and theory' article assumes the role of a specific stimulus activating the central nervous system (CNS) at human birth. This stimulus must have specific features though, such as novelty, efficacy, ubiquity, and immediacy. We propose light as a robust candidate for the CNS activation via the retina. Available data on fetal and neonatal neurodevelopment, in particular with reference to retinal light-responsive pathways, will be examined together with the GABA functional switch, and the subplate disappearance, which, at an experimental level, differentiate the neonatal brain from the fetal brain. In this study, we assume how a very rapid activation of retinal photoreceptors at birth initiates a sudden brain shift from the prenatal pattern of functions to the neonatal setup. Our assumption implies the presence of a photoreceptor capable of capturing and transducing light/photon stimulus, transforming it into an effective signal for the activation of new brain functions at birth. Opsin photoreception or, more specifically, melanopsin-dependent photoreception, which is provided by intrinsically photosensitive retinal ganglion cells (ipRGCs), is considered as a valid candidate. Although what is assumed herein cannot be verified in humans based on knowledge available so far, proposing an important and novel function can trigger a broad range of diversified research in different domains, from neurophysiology to neurology and psychiatry.

Decreasing Intubation for Ineffective Ventilation after Birth for Very Low Birth Weight Neonates

Despite recommendations promoting noninvasive delivery room (DR) ventilation, local historical preterm DR noninvasive ventilation rates were low (50%−64%). Project aims were to improve DR noninvasive ventilation rate in very low birth weight (VLBW) neonates (<1500 g) with a focus on decreasing DR intubations for ineffective positive pressure ventilation (PPV).

Evaluation of T-piece resuscitator in the delivery room management of pre-term neonates with respiratory distress syndrome in resource-limited settings: A pre-post intervention study

The aim of our study was to evaluate the impact of the T-piece resuscitator in the delivery room management of pre-term neonates in a resource-limited setting. We compared the incidence rates of delivery room intubation, surfactant replacement therapy, pulmonary air leak syndrome, and pre-term very low birth weight infant mortality, before and after T-piece use. Bi-monthly neonatal resuscitation training sessions were conducted for healthcare providers during the study period. We emphasized hands-on experience with the T-piece resuscitator and delivery room early respiratory care practices during the post-intervention epoch. Our pre- and post-intervention data recorded statistically significant decline in delivery room intubations, a 32% decrease in surfactant replacement therapy, and a 57% decrease in air leaks in pre-term neonates. However, the use of T-piece resuscitator did not have a statistically significant effect on pre-term very low birth weight infant mortality.

The newborn delivery room of tomorrow: emerging and future technologies

Advances in neonatal care have resulted in improved outcomes for high-risk newborns with technologies playing a significant part although many were developed for the neonatal intensive care unit. The care provided in the delivery room (DR) during the first few minutes of life can impact short- and long-term neonatal outcomes. Increasingly, technologies have a critical role to play in the DR particularly with monitoring and information provision. However, the DR is a unique environment and has major challenges around the period of foetal to neonatal transition that need to be overcome when developing new technologies. This review focuses on current DR technologies as well as those just emerging and further over the horizon. We identify what key opinion leaders in DR care think of current technologies, what the important DR measures are to them, and which technologies might be useful in the future. We link these with key technologies including respiratory function monitors, electoral impedance tomography, videolaryngoscopy, augmented reality, video recording, eye tracking, artificial intelligence, and contactless monitoring. Encouraging funders and industry to address the unique technological challenges of newborn care in the DR will allow the continued improvement of outcomes of high-risk infants from the moment of birth. IMPACT: Technological advances for newborn delivery room care require consideration of the unique environment, the variable patient characteristics, and disease states, as well as human factor challenges. Neonatology as a speciality has embraced technology, allowing its rapid progression and improved outcomes for infants, although innovation in the delivery room often lags behind that in the intensive care unit. Investing in new and emerging technologies can support healthcare providers when optimising care and could improve training, safety, and neonatal outcomes.

Individualized dynamic PEEP (dynPEEP) vs. positive pressure ventilation in delivery room management: A retrospective cohort study

OBJECTIVE

Although nasal continuous positive airway pressure (nCPAP) is recommended in delivery room (DR) management for preterm infants, the effect of delivering nCPAP at 6-8 cmH₂O is not satisfactory. Therefore, we conducted this retrospective cohort study to compare the effects of individualized dynamic positive end-expiratory pressure (dynPEEP) vs. positive pressure ventilation (PPV) in the DR on clinical outcomes.

METHODS

Preterm infants with a gestational age (GA) less than 30 weeks who received PPV (peak inspiratory pressure, PIP/PEEP 15-25/6-8 cmH₂O) from August 2018 to July 2020 were included as Cohort 1 (PPV group, n = 55), and those who received dynPEEP (nCPAP 8-15 cmH₂O) from June 2020 to April 2022 were included as Cohort 2 (dynPEEP group, n = 62). Primary outcomes included the DR intubation rate and the bronchopulmonary dysplasia (BPD) rate. The secondary outcomes included DR stabilization, transfer, admission, respiratory function, and other outcomes.

RESULTS

The percentage of singleton infants was higher in the PPV group (63.6%) than in the dynPEEP group (22.6%, p = 0.000). The DR intubation and chest compression rates were higher in the PPV group (80.0% and 18.2%, respectively) than in the dynPEEP group (45.2%, p = 0.000; 3.0%, p = 0.008, respectively). The percentage of patients with 5-min Apgar scores < 5 was higher in the PPV group (9.1%) than in the dynPEEP group (0%, p = 0.016). The partial pressure of carbon dioxide was lower in the PPV group (49.77 ± 11.28) than in the dynPEEP group (56.44 ± 13.17, p = 0.004), and lactate levels were higher in the PPV group (3.60 (2.10, 5.90)) than in the dynPEEP group (2.25 (1.38, 3.33), p = 0.002). No significant differences in the BPD rate or other secondary outcomes were noted.

CONCLUSIONS

In this retrospective cohort study, the dynPEEP strategy reduced the need for DR intubation compared with PPV. The dynPEEP strategy is feasible and potentially represents an alternative respiratory strategy to PPV. Nevertheless, a randomized control trial is needed to evaluate the dynPEEP strategy.

Sustained Inflation Versus Intermittent Positive Pressure Ventilation for Preterm Infants at Birth: Respiratory Function and Vital Sign Measurements

OBJECTIVE

To characterize respiratory function monitor (RFM) measurements of sustained inflations and intermittent positive pressure ventilation (IPPV) delivered noninvasively to infants in the Sustained Aeration of Infant Lungs (SAIL) trial and to compare vital sign measurements between treatment arms.

STUDY DESIGN

We analyzed RFM data from SAIL participants at 5 trial sites. We assessed tidal volumes, rates of airway obstruction, and mask leak among infants allocated to sustained inflations and IPPV, and we compared pulse rate and oxygen saturation measurements between treatment groups.

RESULTS

Among 70 SAIL participants (36 sustained inflations, 34 IPPV) with RFM measurements, 40 (57%) were spontaneously breathing prior to the randomized intervention. The median expiratory tidal volume of sustained inflations administered was 5.3 mL/kg (IQR 1.1-9.2). Significant mask leak occurred in 15% and airway obstruction occurred during 17% of sustained inflations. Among 34 control infants, the median expiratory tidal volume of IPPV inflations was 4.3 mL/kg (IQR 1.3-6.6). Mask leak was present in 3%, and airway obstruction was present in 17% of IPPV inflations. There were no significant differences in pulse rate or oxygen saturation measurements between groups at any point during resuscitation.

CONCLUSION

Expiratory tidal volumes of sustained inflations and IPPV inflations administered in the SAIL trial were highly variable in both treatment arms. Vital sign values were similar between groups throughout resuscitation. Sustained inflation as operationalized in the SAIL trial was not superior to IPPV to promote lung aeration after birth in this study subgroup.

TRIAL REGISTRATION

Clinicaltrials.gov: NCT02139800.

Respiratory support after delayed cord clamping: a prospective cohort study of at-risk births at ≥35+0 weeks gestation

OBJECTIVE

To identify risk factors associated with delivery room respiratory support in at-risk infants who are initially vigorous and received delayed cord clamping (DCC).

DESIGN

Prospective cohort study.

SETTING

Two perinatal centres in Melbourne, Australia.

PATIENTS

At-risk infants born at ≥35⁺⁰ weeks gestation with a paediatric doctor in attendance who were initially vigorous and received DCC for >60 s.

MAIN OUTCOME MEASURES

Delivery room respiratory support defined as facemask positive pressure ventilation, continuous positive airway pressure and/or supplemental oxygen within 10 min of birth.

RESULTS

Two hundred and ninety-eight infants born at a median (IQR) gestational age of 39⁺³ (38⁺²-40⁺²) weeks were included. Cord clamping occurred at a median (IQR) of 128 (123-145) s. Forty-four (15%) infants received respiratory support at a median of 214 (IQR 156-326) s after birth. Neonatal unit admission for respiratory distress occurred in 32% of infants receiving delivery room respiratory support vs 1% of infants who did not receive delivery room respiratory support (p<0.001). Risk factors independently associated with delivery room respiratory support were average heart rate (HR) at 90-120 s after birth (determined using three-lead ECG), mode of birth and time to establish regular cries. Decision tree analysis identified that infants at highest risk had an average HR of <165 beats per minute at 90-120 s after birth following caesarean section (risk of 39%). Infants with an average HR of ≥165 beats per minute at 90-120 s after birth were at low risk (5%).

CONCLUSIONS

We present a clinical decision pathway for at-risk infants who may benefit from close observation following DCC. Our findings provide a novel perspective of HR beyond the traditional threshold of 100 beats per minute.

Expired carbon dioxide during newborn resuscitation as predictor of outcome

AIM

To explore and compare expired CO₂ (ECO₂) and heart rate (HR), during newborn resuscitation with bag-mask ventilation, as predictors of 24-h outcome.

METHODS

Observational study from March 2013 to June 2017 in a rural Tanzanian hospital. Side-stream measures of ECO₂, ventilation parameters, HR, clinical information, and 24-h outcome were recorded in live born bag-mask ventilated newborns with initial HR < 120 bpm. We analysed the data using logistic regression models and compared areas under the receiver operating curves (AUC) for ECO₂ and HR within three selected time intervals after onset of ventilation (0-30 s, 30.1-60 s and 60.1-300 s).

RESULTS

Among 434 included newborns (median birth weight 3100 g), 378 were alive at 24 h, 56 had died. Both ECO₂ and HR were independently significant predictors of 24-h outcome, with no differences in AUCs. In the first 60 s of ventilation, ECO₂ added extra predictive information compared to HR alone. After 60 s, ECO₂ lost significance when adjusted for HR. In 70% of newborns with initial ECO₂ <2% and HR < 100 bpm, ECO₂ reached ≥2% before HR ≥ 100 bpm. Survival at 24 h was reduced by 17% per minute before ECO₂ reached ≥2% and 44% per minute before HR reached ≥100 bpm.

CONCLUSIONS

Higher levels and a faster rise in ECO₂ and HR during newborn resuscitation were independently associated with improved survival compared to persisting low values. ECO₂ increased before HR and may serve as an earlier predictor of survival.

Something must happen before first breath

BACKGROUND

Definition and concept of the 'beginning of human life' are weakened by co-existing contrasting hypotheses based on humanistic or religious beliefs rather than scientific foundations. This plethora of conceptually distant views have important common concerns in different fields of science and shape, in turn, several societal aspects including laws related, for instance, to inheritance eligibility or abortion, end-of-life care and euthanasia, and reproductive technology. Also, they are fundamental to evaluate opportunity for resuscitation vs. palliative care in extremely preterm infants. In this article, we address one of the most common tenets in medicine: the acceptance that human life starts with first breath, even though several events are well-documented to take place before its occurrence.

MAIN TEXT

Several studies show how pivotal physiological events take place before first breath. Evidence of a number of neurological events occurring before first breath opens the way to the primacy of the Central Nervous System, given its immediate extra-uterine activation at birth. This activation eventually sets specific physiological conditions that allow the complex sequence of events determining the muscle activity associated with the influx of air in the lung and the settling of a continuous and successful extra-uterine respiration. We would like to invite the scientific community to endorse a clear-cut position against the paradigm of 'first breath' as the beginning of life. Herein, we also assume how, a still undefined, yet possibly specific quid in the external environment triggers further physiological response in newborns. Better understanding of the critical events that occur at the beginning of human life is likely to cause great concern and expectations in scientists, researchers and physicians working in the domain of brain, and its physiology, and mental health.

CONCLUSIONS

The comparison between beliefs and evidence-based observations generates confusion, misperceptions and false expectations in society, hence, in the scientific and medical community. Different and more solid alternatives about the carachterization of the 'beginning of human life' are indeed available and require to be explored and defined.

European Resuscitation Council Guidelines 2021: Newborn resuscitation and support of transition of infants at birth

The European Resuscitation Council has produced these newborn life support guidelines, which are based on the International Liaison Committee on Resuscitation (ILCOR) 2020 Consensus on Science and Treatment Recommendations (CoSTR) for Neonatal Life Support. The guidelines cover the management of the term and preterm infant. The topics covered include an algorithm to aid a logical approach to resuscitation of the newborn, factors before delivery, training and education, thermal control, management of the umbilical cord after birth, initial assessment and categorisation of the newborn infant, airway and breathing and circulation support, communication with parents, considerations when withholding and discontinuing support.

A Single-Center Observational Clinical Study on Factors Associated with Regional Cerebral Oxygen Saturation in Full-Term Newborn Infants During Birth Transition

Background

Hypoxic hypoperfusion injury in the brain is a cause of potential injury and even death in the growth period of newborns. Therefore, monitoring regional cerebral oxygen saturation (CrSO₂) during this period is particularly important. This observational clinical study from a single center aimed to investigate the factors associated with CrSO₂ in full-term newborn infants during birth transition.

Material/Methods

We enrolled 84 full-term newborn infants delivered by cesarean section. We started the stopwatch with the obstetrician clamping the newborns’ umbilical cords and recorded the values of newborns’ CrSO₂, pulse oxygen saturation (SpO₂)_, pulse rate (PR), end-tidal carbon dioxide (EtCO₂), and respiratory rate (RR) at 2 min, 5 min, and 10 min. We weighed the newborns before they left the operating room and used statistical methods to compare the correlation between each observation factor.

Results

Pearson correlation coefficients between CrSO₂ and SpO₂ measured at 2 min, 5 min, and 10 min were 0.491, 0.599, and 0.587, respectively (P<0.01). Pearson correlation coefficients between CrSO₂ and EtCO₂ measured at 2 min, 5 min, and 10 min were −0.304, −0.443, and −0.243, respectively (P<0.05). Regardless of a newborn’s weight, PR, or RR, the correlation between any of those factors and the value of CrSO₂ measured at the corresponding time point had no significance (P>0.05).

Conclusions

This study showed a correlation between CrSO₂ and SpO₂ and CrSO₂ and EtCO₂ during birth transition of full-term infants delivered by elective cesarean section, but CrSO₂ had no significant correlation with neonatal weight, PR, or RR.

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.

Sustained Lung Inflation in Pre-term Infants at Birth: A Randomized Controlled Trial

BACKGROUND

Invasive mechanical ventilation (IMV) of pre-term infants may be associated with high rate of mortality and iatrogenic complications in low- and middle-income countries. Sustained lung inflation (SLI) may help to reduce their need for IMV.

METHODS

This randomized controlled trial included 160 infants with gestational age (GA) ≥27 and ≤32 weeks who were randomly assigned to receive either SLI; using a pressure of 20 cmH2O for 15 s followed by nasal continuous positive airway pressure (CPAP) of 5 cmH2O or nasal CPAP alone, through an appropriate mask and a T-piece resuscitator. Primary outcome was the need for IMV in the first 72 h of life.

RESULTS

There was no difference in the primary outcome between SLI group; 55% (44 out of 80) and the control group; 65% (52 out of 80) [odds ratio (OR): 0.623, 95% confidence interval (CI): 0.33-1.18; p = 0.145]. However, SLI significantly reduced the primary outcome in the sicker infants; who had clinical eligibility criteria (CEC; OR: 0.224, 95% CI: 0.076-0.663; p = 0.005) and in the smaller babies; whose GA was <30 weeks (OR: 0.183, 95% CI: 0.053-0.635; p = 0.005).

CONCLUSION

SLI was not harmful. Although, it did not lead to reduction in the need for IMV in the first 72 h of life in pre-term infants with GA ≥27 and ≤32 weeks, SLI reduced this outcome in the subgroup of infants with CEC and those with GA <30 weeks. Future trials are needed to investigate the effect of SLI on these two subgroups.

TRIAL REGISTRATION

Clinical trials.gov, NCT03518762. https://www.clinicaltrials.gov/ct2/show/NCT03518762?term=NCT03518762&rank=1.

[Newborn resuscitation and support of transition of infants at birth]

The European Resuscitation Council has produced these newborn life support guidelines, which are based on the International Liaison Committee on Resuscitation (ILCOR) 2020 Consensus on Science and Treatment Recommendations (CoSTR) for Neonatal Life Support. The guidelines cover the management of the term and preterm infant. The topics covered include an algorithm to aid a logical approach to resuscitation of the newborn, factors before delivery, training and education, thermal control, management of the umbilical cord after birth, initial assessment and categorisation of the newborn infant, airway and breathing and circulation support, communication with parents, considerations when withholding and discontinuing support.

2020 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations

This 2020 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations (CoSTR) for neonatal life support includes evidence from 7 systematic reviews, 3 scoping reviews, and 12 evidence updates. The Neonatal Life Support Task Force generally determined by consensus the type of evidence evaluation to perform; the topics for the evidence updates followed consultation with International Liaison Committee on Resuscitation member resuscitation councils. The 2020 CoSTRs for neonatal life support are published either as new statements or, if appropriate, reiterations of existing statements when the task force found they remained valid.Evidence review topics of particular interest include the use of suction in the presence of both clear and meconium-stained amniotic fluid, sustained inflations for initiation of positive-pressure ventilation, initial oxygen concentrations for initiation of resuscitation in both preterm and term infants, use of epinephrine (adrenaline) when ventilation and compressions fail to stabilize the newborn infant, appropriate routes of drug delivery during resuscitation, and consideration of when it is appropriate to redirect resuscitation efforts after significant efforts have failed.All sections of the Neonatal Resuscitation Algorithm are addressed, from preparation through to postresuscitation care. This document now forms the basis for ongoing evidence evaluation and reevaluation, which will be triggered as further evidence is published.Over 140 million babies are born annually worldwide (https://ourworldindata.org/grapher/births-and-deaths-projected-to-2100). If up to 5% receive positive-pressure ventilation, this evidence evaluation is relevant to more than 7 million newborn infants every year. However, in terms of early care of the newborn infant, some of the topics addressed are relevant to every single baby born.

Recent Advances in Pathophysiology and Management of Transient Tachypnea of Newborn

Transient tachypnea of newborn (TTN) results from failure of the newborn to effectively clear the fetal lung fluid soon after birth. TTN represents the most common etiology of respiratory distress in term gestation newborns and sometimes requires admission to the neonatal intensive care unit. TTN can lead to maternal-infant separation, the need for respiratory support, extended unnecessary exposure to antibiotics and prolonged hospital stays. Recent evidence also suggests that TTN may be associated with wheezing syndromes later in childhood. New imaging modalities such as lung ultrasound can help in the diagnosis of TTN and early management with distending pressure using continuous positive airway pressure may prevent exacerbation of respiratory distress.

Neonatal Life Support: 2020 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations

This 2020 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations (CoSTR) for neonatal life support includes evidence from 7 systematic reviews, 3 scoping reviews, and 12 evidence updates. The Neonatal Life Support Task Force generally determined by consensus the type of evidence evaluation to perform; the topics for the evidence updates followed consultation with International Liaison Committee on Resuscitation member resuscitation councils. The 2020 CoSTRs for neonatal life support are published either as new statements or, if appropriate, reiterations of existing statements when the task force found they remained valid. Evidence review topics of particular interest include the use of suction in the presence of both clear and meconium-stained amniotic fluid, sustained inflations for initiation of positive-pressure ventilation, initial oxygen concentrations for initiation of resuscitation in both preterm and term infants, use of epinephrine (adrenaline) when ventilation and compressions fail to stabilize the newborn infant, appropriate routes of drug delivery during resuscitation, and consideration of when it is appropriate to redirect resuscitation efforts after significant efforts have failed. All sections of the Neonatal Resuscitation Algorithm are addressed, from preparation through to postresuscitation care. This document now forms the basis for ongoing evidence evaluation and reevaluation, which will be triggered as further evidence is published. Over 140 million babies are born annually worldwide (https://ourworldindata.org/grapher/births-and-deaths-projected-to-2100). If up to 5% receive positive-pressure ventilation, this evidence evaluation is relevant to more than 7 million newborn infants every year. However, in terms of early care of the newborn infant, some of the topics addressed are relevant to every single baby born.

Noninvasive Ventilation in the Delivery Room for the Preterm Infant

A decade ago, preterm infants were prophylactically intubated and mechanically ventilated starting in the delivery room; however, now the shift is toward maintaining even the smallest of neonates on noninvasive respiratory support. The resuscitation of very low gestational age neonates continues to push the boundaries of neonatal care, as the events that transpire during the golden minutes right after birth prove ever more important for determining long-term neurodevelopmental outcomes. Continuous positive airway pressure (CPAP) remains the most important mode of noninvasive respiratory support for the preterm infant to establish and maintain functional residual capacity and decrease ventilation/perfusion mismatch. However, the majority of extremely low gestational age infants require face mask positive pressure ventilation during initial stabilization before receiving CPAP. Effectiveness of face mask positive pressure ventilation depends on the ability to detect and overcome mask leak and airway obstruction. In this review, the current evidence on devices and techniques of noninvasive ventilation in the delivery room are discussed.

Do commonly available round facemasks fit near-term and term infants?

OBJECTIVE

With inappropriately large facemasks, it is more difficult to create a seal on the face, potentially leading to ineffective ventilation during neonatal stabilisation. We investigated whether commonly available round facemasks are of appropriate size by measuring facial dimensions in near-term and term infants using two-dimensional (2D) and three-dimensional (3D) images.

DESIGN

Prospective single-centre observational study.

SETTING

Infants born in our centre at 34-41 weeks' gestation were eligible.

INTERVENTION

Patients were photographed with 2D and 3D technique.

MAIN OUTCOME MEASURES

Distances between nasion and gnathion were measured and compared with the outer diameter of various round facemasks.

METHODS

2D and 3D images were performed using standard equipment. Correlations between gestational age and the above-mentioned distances were assessed using Pearson's r.

RESULTS

Images were taken from 102 infants with a mean (SD) gestational age of 37.9 (2.3) weeks. Mean distance between nasion and gnathion was 46.9 mm (5.1) in 2D and 49.9 mm (4.1) in 3D images, that is, on average 3 mm smaller in 2D than with 3D (p<0.01). Based on these measurements, round facemasks with an external diameter of 50 mm seemed fitting for most (61%) term infants and 42 mm masks for most (72%) near-term infants (GA 34-36 weeks).

CONCLUSIONS

Round facemasks with an external diameter of 60 mm are too large for almost all newborn infants, while 42/50 mm round facemasks are well fitting. Important anatomical structures were only visible using 3D images.

CLINICAL TRIAL REGISTRATION NUMBER

NCT03369028.

Establishment of functional residual capacity at birth: Observational study of 821 neonatal resuscitations

AIM OF THE STUDY

Establishing functional residual capacity (FRC) during positive pressure ventilation (PPV) of apnoeic neonates is critical for survival. This may be difficult due to liquid-filled airways contributing to low lung compliance. The objectives were to describe initial PPV, changes in lung compliance and establishment of FRC in near-term/term neonates ≥36 weeks gestation at birth.

METHODS

Observational study of all neonatal resuscitations between 01.07.13 and 30.06.18 in a Tanzanian referral hospital. Perinatal events and characteristics were observed and recorded by trained research assistants. PPV were performed using self-inflating bag-masks without positive end-expiratory pressure (PEEP). Ventilation signals (pressure/flow), expired CO₂ (ECO₂) and heart rate were recorded by resuscitation monitors.

RESULTS

19,587 neonates were born, 1451 received PPV, of these 821 of median (p25, p75) birthweight 3180 (2844, 3500) grams and gestation 38 (37, 40) weeks had ≥20 ventilations and complete datasets. There was a significant increase in expired volume (from 3.3 to 6.0 ml/kg), ECO₂ (0.3-2.4%), lung compliance (0.13-0.19 ml/kg/mbar) and heart rate (109-138 beats/min) over the first 20 PPVs. Inflation volume, time, and peak inflation pressure (PIP) were stable around 12-13 ml/kg, 0.45 s, and 36 mbar, respectively.

CONCLUSIONS

The combination of increasing expired volumes, ECO₂, and heart rate with decreasing inflation/expired volume ratios and constant PIP, suggests establishment of FRC during the first 20 PPVs in near-term/term neonates using a self-inflating bag-mask without PEEP, the most common device worldwide for ventilating non-breathing neonates. Initial lung compliance is low, and with short inflation times, higher than recommended PIP seem necessary to deliver adequate tidal volumes.

Interactions of Symbiotic Partners Drive the Development of a Complex Biogeography in the Squid-Vibrio Symbiosis

The complexity, inaccessibility, and time scales of initial colonization of most animal microbiomes present challenges for the characterization of how the bacterial symbionts influence the form and function of tissues in the minutes to hours following the initial interaction of the partners. Here, we use the naturally occurring binary squid-vibrio association to explore this phenomenon. Imaging of the spatiotemporal landscape of this symbiosis during its onset provides a window into the impact of differences in both host-tissue maturation and symbiont strain phenotypes on the establishment of a dynamically stable symbiotic system. These data provide evidence that the symbionts shape the host-tissue landscape and that tissue maturation impacts the influence of strain-level differences on the daily rhythms of the symbiosis, the competitiveness for colonization, and antibiotic sensitivity.

Microbes live in complex microniches within host tissues, but how symbiotic partners communicate to create such niches during development remains largely unexplored. Using confocal microscopy and symbiont genetics, we characterized the shaping of host microenvironments during light organ colonization of the squid Euprymna scolopes by the bacterium Vibrio fischeri. During embryogenesis, three pairs of invaginations form sequentially on the organ’s surface, producing pores that lead to interior compressed tubules at different stages of development. After hatching, these areas expand, allowing V. fischeri cells to enter and migrate ∼120 μm through three anatomically distinct regions before reaching blind-ended crypt spaces. A dynamic gatekeeper, or bottleneck, connects these crypts with the migration path. Once V. fischeri cells have entered the crypts, the bottlenecks narrow, and colonization by the symbiont population becomes spatially restricted. The actual timing of constriction and restriction varies with crypt maturity and with different V. fischeri strains. Subsequently, starting with the first dawn following colonization, the bottleneck controls a lifelong cycle of dawn-triggered expulsions of most of the symbionts into the environment and a subsequent regrowth in the crypts. Unlike other developmental phenotypes, bottleneck constriction is not induced by known microbe-associated molecular patterns (MAMPs) or by V. fischeri-produced bioluminescence, but it does require metabolically active symbionts. Further, while symbionts in the most mature crypts have a higher proportion of live cells and a greater likelihood of expulsion at dawn, they have a lower resistance to antibiotics. The overall dynamics of these distinct microenvironments reflect the complexity of the host-symbiont dialogue.

Defining information needs in neonatal resuscitation with work domain analysis

OBJECTIVE

To gain a deeper understanding of the information requirements of clinicians conducting neonatal resuscitation in the first 10 min after birth.

BACKGROUND

During the resuscitation of a newborn infant in the first minutes after birth, clinicians must monitor crucial physiological adjustments that are relatively unobservable, unpredictable, and highly variable. Clinicians' access to information regarding the physiological status of the infant is also crucial to determining which interventions are most appropriate. To design displays to support clinicians during newborn resuscitation, we must first carefully consider the information requirements.

METHODS

We conducted a work domain analysis (WDA) for the neonatal transition in the first 10 min after birth. We split the work domain into two 'subdomains'; the physiology of the neonatal transition, and the clinical resources supporting the neonatal transition. A WDA can reveal information requirements that are not yet supported by resources.

RESULTS

The physiological WDA acted as a conceptual tool to model the exact processes and functions that clinicians must monitor and potentially support during the neonatal transition. Importantly, the clinical resources WDA revealed several capabilities and limitations of the physical objects in the work domain-ultimately revealing which physiological functions currently have no existing sensor to provide clinicians with information regarding their status.

CONCLUSION

We propose two potential approaches to improving the clinician's information environment: (1) developing new sensors for the information we lack, and (2) employing principles of ecological interface design to present currently available information to the clinician in a more effective way.

Initiating resuscitation before umbilical cord clamping in infants with congenital diaphragmatic hernia: a pilot feasibility trial

BACKGROUND

Infants with congenital diaphragmatic hernia (CDH) often experience hypoxaemia with acidosis immediately after birth. The traditional approach in the delivery room is immediate cord clamping followed by intubation. Initiating resuscitation prior to umbilical cord clamping (UCC) may support this transition.

OBJECTIVES

To establish the safety and feasibility of intubation and ventilation prior to UCC for infants with CDH. To compare short-term outcomes between trial participants and matched controls treated with immediate cord clamping before intubation and ventilation.

DESIGN

Single-arm, single-site trial of infants with CDH and gestational age ≥36 weeks. Infants were placed on a trolley immediately after birth and underwent intubation and ventilation, with UCC performed after qualitative CO₂ detection. The primary feasibility endpoint was successful intubation prior to UCC. Prespecified safety and physiological outcomes were compared with historical controls matched for prognostic variables using standard bivariate tests.

RESULTS

Of 20 enrolled infants, all were placed on the trolley, and 17 (85%) infants were intubated before UCC. The first haemoglobin and mean blood pressure at 1 hour of life were significantly higher in trial participants than controls. There were no significant differences between groups for subsequent blood pressure values, vasoactive medications, inhaled nitric oxide or extracorporeal membrane oxygenation. Blood gas and oxygenation index values did not differ between groups at any point.

CONCLUSIONS

Intubation and ventilation prior to UCC is safe and feasible among infants with CDH. The impact of this approach on clinically relevant outcomes deserves investigation in a randomised trial.

Comprehensive Quantitative Assessment of Lung Liquid Clearance by Lung Ultrasound Score in Neonates with No Lung Disease during the First 24 Hours

Objectives

To comprehensively and quantitatively assess the process of lung liquid clearance using the lung ultrasound score. This study is to evaluate the whole healthy lungs of neonates during the first 24 h.

Methods

Lung ultrasound was performed in neonates with no respiratory symptoms within 3 h after birth, and scans were then repeated at 6 hours and 24 hours, respectively. The entire chest wall was divided into 12 regions. The lung ultrasound scores of the anterior, posterior, upper, and lower regions and sum of all regions were calculated according to the ultrasound pattern of each region examined.

Results

The total lung ultrasound score decreased gradually during the first 24 h, with the total lung ultrasound score at 6 h being significantly lower than that at <3 h (P < 0.05). At <3 h, B-lines were more abundant in the posterior chest than in the anterior chest (P < 0.05). At <3 h, B-lines were more abundant in the posterior chest than in the anterior chest (P < 0.05). At <3 h, B-lines were more abundant in the posterior chest than in the anterior chest (.

Conclusion

Changes in the lung ultrasound score may quantitatively reflect the characteristics of different regions and processes of lung liquid clearance during the first 24 h.

Effect of sustained inflations and intermittent positive pressure ventilation on bronchopulmonary dysplasia or death among neonatal: A protocol for systematic review

BACKGROUND

Sustained Inflations (SI) and Intermittent Positive Pressure Ventilation (IPPV) are two interventions to prevent Bronchopulmonary dysplasia (BPD). The aim of this study is to assess the effect of these two interventions.

METHODS

The databases of PubMed, EMBASE, and Cochrane Central Register of Controlled Trials (CENTRAL) will be comprehensively searched from inception to September 2019. All RCTs and quasi-RCTs which compare the efficacy of SI vs IPPV among preterm infants are eligible. We will assess the methodological quality using the Cochrane Handbook version 5.1.0. A meta-analysis will be performed using RevMan 5.3 software and the results will be presented using risk ratios (RRs) and 95% confidence intervals (CIs).

CONCLUSIONS

This study will provide strong evidence for assessing the effect of SI and IPPV on BPD or death among preterm infants.

PROSPERO REGISTRATION NUMBER

CRD42019135816.

Enhanced monitoring during neonatal resuscitation

Immediately after birth through spontaneous breaths, infants' clear lung liquid replacing it with air, and gradually establishing a functional residual capacity to achieve gas exchange. Most infants start breathing independently after birth and ~3% of infants who require positive pressure ventilation. When newborns fail to start breathing the current neonatal resuscitation guidelines recommend initiatingpositive pressure ventilationusing a face mask and a ventilation device. Adequate ventilation is the cornerstone of successful neonatal resuscitation; therefore, it is mandatory that anybody involved in neonatal resuscitation is trained in mask ventilation techniques. One of the main problems with mask ventilation is that it is very subjective with direct feedback lacking and not uncommonly, the resuscitator does not realise that their technique is unsatisfactory. Many studies have shown that monitoring tidal volume and leak around the mask or endotracheal tube enables the resuscitator to identify the problem and adjust their technique to reduce the leak and deliver and appropriate tidal volume. This chapter discusses the currently available monitoring devices used during stabilization/resuscitation in the delivery room.

Issues in cardiopulmonary transition at birth

The transition from fetal to newborn life involves a complex series of physiological events that commences with lung aeration, which is thought to involve 3 mechanisms. Two mechanisms occur during labour, Na⁺ reabsorption and fetal postural changes, and one occurs after birth due to pressure gradients generated by inspiration. However, only one of these mechanisms, fetal postural changes, involves the loss of liquid from the respiratory system. Both other mechanisms involve liquid being reabsorbed from the airways into lung tissue. While this stimulates an increase in pulmonary blood flow (PBF), in large quantities this liquid can adversely affect postnatal respiratory function. The increase in PBF (i) facilitates the onset of pulmonary gas exchange and (ii) allows pulmonary venous return to take over the role of providing preload for the left ventricle, a role played by umbilical venous return during fetal life. Thus, aerating the lung and increasing PBF before umbilical cord clamping (known as physiological based cord clamping), can avoid the loss of preload and reduction in cardiac output that normally accompanies immediate cord clamping.

Caesarean section and children's health: A quasi-experimental design

The prevalence of inflammatory child health conditions-such as asthma, eczema, and food allergy-and their associated costs have increased rapidly over the last 30 years. While environmental factors likely underpin these increases, recent studies explain only a fraction of the trend and rely on associational methods. Caesarean (or C-) section rates increased dramatically in the period of interest, and this method of delivery is an understudied environmental factor linked to child health outcomes via the gut microbiome. We fuse 22 years of birth cohort data from the United States National Surveys of Children's Health with C-section rates from the National Vital Statistics System generated for subgroups based on state, sex, race, Hispanic origin, and birth year. Then, we model the effects of C-section on rates of asthma, eczema, and food allergy using a quasi-experimental fixed effects design. We find that C-section significantly predicts food allergy, with qualitatively significant implications.

Predictors for expired CO2 in neonatal bag-mask ventilation at birth: observational study

BACKGROUND

Expired carbon dioxide (ECO2) indicates degree of lung aeration immediately after birth. Favourable ventilation techniques may be associated with higher ECO2 and a faster increase. Clinical condition will however also affect measured values. The aim of this study was to explore the relative impact of ventilation factors and clinical factors on ECO2 during bag-mask ventilation of near-term newborns.

METHODS

Observational study performed in a Tanzanian rural hospital. Side-stream measures of ECO2, ventilation data, heart rate and clinical information were recorded in 434 bag-mask ventilated newborns with initial heart rate <120 beats per minute. We studied ECO2 by clinical factors (birth weight, Apgar scores and initial heart rate) and ventilation factors (expired tidal volume, ventilation frequency, mask leak and inflation pressure) in random intercept models and Cox regression for time to ECO2 >2%.

RESULTS

ECO2 rose non-linearly with increasing expired tidal volume up to >10 mL/kg, and sufficient tidal volume was critical for the time to reach ECO2 >2%. Ventilation frequency around 30/min was associated with the highest ECO2. Higher birth weight, Apgar scores and initial heart rate were weak, but significant predictors for higher ECO2. Ventilation factors explained 31% of the variation in ECO2 compared with 11% for clinical factors.

CONCLUSIONS

Our findings indicate that higher tidal volumes than currently recommended and a low ventilation frequency around 30/min are associated with improved lung aeration during newborn resuscitation. Low ECO2 may be used to identify unfavourable ventilation technique. Clinical factors are also associated with persistently low ECO2 and must be accounted for in the interpretation.

Postnatal gene expression of airway epithelial sodium transporters associated with birth stress in humans

INTRODUCTION

Lung fluid clearance is essential for successful postnatal pulmonary adaptation. The epithelial sodium channel (ENaC) and Na-K-ATPase, induced by serum- and glucocorticoid-inducible kinase 1 (SGK1) as well as aquaporins (AQP), represent key players in the switch from fetal lung fluid secretion to absorption and in early postnatal lung fluid balance. Birth stress, including a surge in catecholamines, promotes pulmonary adaptation, likely through the augmentation of epithelial sodium reabsorption.

OBJECTIVES

We sought to determine the changes in the airway gene expression of molecules vital to epithelial sodium transport during early pulmonary adaptation, and the association with birth stress reflected in the norepinephrine concentration in the cord blood in humans.

METHODS

We included 70 term newborns: 28 born via vaginal delivery and 42 via elective cesarean section. We determined the norepinephrine concentrations in the cord blood using tandem mass spectrometry and collected nasal epithelial cell samples at 2 min, 1 h, and 24 h postnatally to quantify ENaC, Na-K-ATPase, AQP5, and SGK1 mRNAs using RT-PCR.

RESULTS

The molecular gene expression involved in airway epithelium sodium transport changed markedly within the first hour postnatally. Newborns born via elective cesarean section exhibited a lower expression of ENaC, Na-K-ATPase, and SGK1. Significant correlations existed between the expressions of ENaC, Na-K-ATPase, and SGK1, and the concentration of norepinephrine in the cord blood.

CONCLUSIONS

The association of ENaC, Na-K-ATPase, and SGK1 expression with the cord blood norepinephrine concentration points to the importance of birth stress in promoting lung fluid clearance during early postnatal pulmonary adaptation.

Visual attention on a respiratory function monitor during simulated neonatal resuscitation: an eye-tracking study

OBJECTIVE

A respiratory function monitor (RFM) may improve positive pressure ventilation (PPV) technique, but many providers do not use RFM data appropriately during delivery room resuscitation. We sought to use eye-tracking technology to identify RFM parameters that neonatal providers view most commonly during simulated PPV.

DESIGN

Mixed methods study. Neonatal providers performed RFM-guided PPV on a neonatal manikin while wearing eye-tracking glasses to quantify visual attention on displayed RFM parameters (ie, exhaled tidal volume, flow, leak). Participants subsequently provided qualitative feedback on the eye-tracking glasses.

SETTING

Level 3 academic neonatal intensive care unit.

PARTICIPANTS

Twenty neonatal resuscitation providers.

MAIN OUTCOME MEASURES

Visual attention: overall gaze sample percentage; total gaze duration, visit count and average visit duration for each displayed RFM parameter. Qualitative feedback: willingness to wear eye-tracking glasses during clinical resuscitation.

RESULTS

Twenty providers participated in this study. The mean gaze sample captured wa s 93% (SD 4%). Exhaled tidal volume waveform was the RFM parameter with the highest total gaze duration (median 23%, IQR 13-51%), highest visit count (median 5.17 per 10 s, IQR 2.82-6.16) and longest visit duration (median 0.48 s, IQR 0.38-0.81 s). All participants were willing to wear the glasses during clinical resuscitation.

CONCLUSION

Wearable eye-tracking technology is feasible to identify gaze fixation on the RFM display and is well accepted by providers. Neonatal providers look at exhaled tidal volume more than any other RFM parameter. Future applications of eye-tracking technology include use during clinical resuscitation.

T-piece resuscitators: how do they compare?

BACKGROUND

The T-piece resuscitator (TPR) has seen increased use as a primary resuscitation device with newborns. Traditional TPR design uses a high resistance expiratory valve to produce positive end expiratory pressure (PEEP) or continuous positive airway pressure (CPAP) at resuscitation. A new TPR device that uses a dual flow ratio valve (fluidic flip) to produce PEEP/CPAP is now available (rPAP). We aimed to compare the measured ventilation performance of different TPR devices in a controlled bench test study.

DESIGN/METHODS

Single operator provided positive pressure ventilation to an incremental testlung compliance (Crs) model (0.5-5 mL/cmH₂O) with five different brands of TPR device (Atom, Neopuff, rPAP, GE Panda warmer and Draeger Resuscitaire). At recommended peak inflation pressure (PIP) 20 cmH₂O, PEEP of 5 cmH₂O and rate of 60 inflations per minute.

RESULTS

1864 inflations were analysed. Four of the five devices tested demonstrated inadvertent elevations in mean PEEP (5.5-10.3 cmH₂O, p<0.001) from set value as Crs was increased, while one device (rPAP) remained at the set value. Measured PIP exceeded the set value in two infant warmer devices (GE and Draeger) with inbuilt TPR at Crs of 0.5 (24.5 and 23.5 cmH₂O, p<0.001). Significant differences were seen in tidal volumes across devices particularly at higher Crs (p<0.001).

CONCLUSIONS

Results show important variation in delivered ventilation from set values due to inherent TPR device design characteristics with a range of lung compliances expected at birth. Device-generated inadvertent PEEP and overdelivery of PIP may be clinically deleterious for term and preterm newborns or infants with larger Crs during resuscitation.

Supporting breathing of preterm infants at birth: a narrative review

Most very preterm infants have difficulty aerating their lungs and require respiratory support at birth. Currently in clinical practice, non-invasive ventilation in the form of continuous positive airway pressure (CPAP) and positive pressure ventilation (PPV) is applied via facemask. As most very preterm infants breathe weakly and unnoticed at birth, PPV is often administered. PPV is, however, frequently ineffective due to pressure settings, mask leak and airway obstruction. Meanwhile, high positive inspiratory pressures and spontaneous breathing coinciding with inflations can generate high tidal volumes. Evidence from preclinical studies demonstrates that high tidal volumes can be injurious to the lungs and brains of premature newborns. To reduce the need for PPV in the delivery room, it should be considered to optimise spontaneous breathing with CPAP. CPAP is recommended in guidelines and commonly used in the delivery room after a period of PPV, but little data is available on the ideal CPAP strategy and CPAP delivering devices and interfaces used in the delivery room. This narrative review summarises the currently available evidence for why PPV can be inadequate at birth and what is known about different CPAP strategies, devices and interfaces used the delivery room.

Comparison of Two Respiratory Support Strategies for Stabilization of Very Preterm Infants at Birth: A Matched-Pairs Analysis

Objective: Respiratory support for stabilizing very preterm infants at birth varies between centers. We retrospectively compared two strategies that involved either increasing continuous positive airway pressures (CPAP), or increasing oxygen supplementation. Methods: Matched-pairs of infants (<28 weeks of gestation) were born either at the Leiden University Medical Center [low-pressure: CPAP 5-8 cmH₂O and/or positive pressure ventilation (PPV) and fraction of inspired oxygen (FiO₂) 0.3-1.0; n = 27], or at the University Hospital of Cologne (high-pressure: CPAP 12-35 cmH₂O, no PPV and FiO₂ 0.3-0.4; n = 27). Respiratory support was initiated non-invasively via facemask at both units. Infants (n = 54) were matched between centers for gestational age and birth weight, to compare physiological and short-term clinical outcomes. Results: In the low-pressure group, 20/27 (74%) infants received 1-2 sustained inflations (20, 25 cm H₂O) and 22/27 (81%) received PPV (1:19-3:01 min) using pressures of 25-27 cm H₂O. Within 3 min of birth [median (IQR)], mean airway pressures [12 (6-15) vs. 19 (16-23) cmH₂O, p < 0.001] and FiO₂ [0.30 (0.28-0.31) vs. 0.22 (0.21-0.30), p < 0.001] were different in low- vs. high-pressure groups, respectively. SpO₂ and heart rates were similar. After 3 min, higher FiO₂ levels [0.62 (0.35-0.98) vs. 0.28 (0.22-0.38), p = 0.005] produced higher SpO₂ levels [77 (50-92) vs. 53 (42-69)%, p < 0.001] in the low-pressure group, but SpO₂/FiO₂ and heart rates were similar. While intubation rates during admission were significantly different (70 vs. 30%, p = 0.013), pneumothorax rates (4 vs. 19%, p = 0.125) and the occurrence of spontaneous intestinal perforations (0 vs. 15%, p = 0.125) were similar between groups. Conclusion: Infants (<28 weeks) can be supported non-invasively at birth with either higher or lower pressures and while higher-pressure support may require less oxygen, it does not eliminate the need for oxygen supplementation. Future studies need to examine the effect of high pressures and pressure titration in the delivery room.