The journey towards lung protective respiratory support in preterm neonates

Association of Antenatal Terbutaline and Respiratory Support Requirements in Preterm Neonates

BACKGROUND

Before the advent of antenatal steroids, early non-invasive respiratory support (NIV), and intratracheal surfactant, antenatal terbutaline was also used to improve lung compliance and reduce the incidence of respiratory distress syndrome (RDS).

OBJECTIVES

The objective of this paper was to study the association between antenatal terbutaline and endotracheal intubation (ET) within the first 24 hours of life, RDS, bronchopulmonary dysplasia (BPD), and intraventricular hemorrhage (IVH) in infants with the gestational age (GA) of <32 weeks, and to study the association between antenatal terbutaline, and ET or NIV within the first 24 hours of life, and RDS in infants with the GA of 32 to 36 weeks.

METHOD

This was a retrospective medical record review of preterm infants delivered at a single tertiary care center from October 2016 to December 2020. Multivariable logistic regression was used to explore the association between antenatal terbutaline and neonatal respiratory support.

RESULT

1,794 infants were included, 234 (13.0%) had the GA of <32 weeks and 1,560 (86.9%) had the GA of 32 to 36 weeks. Antenatal terbutaline, corticosteroid, or both agents were administered in 561 (31.3%), 1,461 (81.4%), and 555 (30.9%), respectively. Antenatal terbutaline was significantly associated with a reduction in ET (adjusted odds ratio [aOR] = 0.40, 95% confident interval [CI] 0.19-0.82, p = 0.012) in infants with the GA of <32 weeks, but not in infants with the GA of 32-36 weeks. Antenatal terbutaline was not associated with RDS or BPD but was significantly associated with a reduction in grade III-IV IVH (aOR 0.11, CI 0.01-0.98; p = 0.048), in infants with the GA of <32 weeks.

CONCLUSION

In a state-of-the-art neonatal care setting, antenatal terbutaline was associated with a reduction in ET during the first 24 hours in infants with the GA of <32 weeks. The use of antenatal terbutaline to improve acute neonatal respiratory outcomes merits reconsideration.

KEY POINTS

· The neonatal respiratory benefits of antenatal terbutaline in the era of antenatal corticosteroids were uncertain.. · Terbutaline is associated with a reduction in endotracheal intubation in a modern care setting.. · The role of terbutaline, and potentially other betamimetics, to improve neonatal respiratory outcomes merits reconsideration..

Non-invasive versus invasive respiratory support in preterm infants

Respiratory insufficiency is almost ubiquitous in infants born preterm, with its incidence increasing with lower gestational age. A wide range of respiratory support management strategies are available for these infants, separable into non-invasive and invasive forms of respiratory support. Here we review the history and evolution of respiratory care for the preterm infant and then examine evidence that has emerged to support a non-invasive approach to respiratory management where able. Continuous positive airway pressure (CPAP) is the non-invasive respiratory support mode currently with the most evidence for benefit. CPAP can be delivered safely and effectively and can commence in the delivery room. Particularly in early life, time spent on non-invasive respiratory support, avoiding intubation and mechanical ventilation, affords benefit for the preterm infant by virtue of a lessening of lung injury and hence a reduction in incidence of bronchopulmonary dysplasia. In recent years, enthusiasm for application of non-invasive support has been further bolstered by new techniques for administration of exogenous surfactant. Methods of less invasive surfactant delivery, in particular with a thin catheter, have allowed neonatologists to administer surfactant without resort to endotracheal intubation. The benefits of this approach appear to be sustained, even in those infants subsequently requiring mechanical ventilation. This cements the notion that any reduction in exposure to mechanical ventilation leads to alleviation of injury to the vulnerable preterm lung, with a long-lasting effect. Despite the clear advantages of non-invasive respiratory support, there will continue to be a role for intubation and mechanical ventilation in some preterm infants, particularly for those born <25 weeks' gestation. It is currently unclear what role early non-invasive support has in this special population, with more studies required.

Geographical distribution of antimicrobial exposure among very preterm and very low birth weight infants: A nationwide database study in Japan

OBJECTIVES

To examine spatial effects in neonatal care, we conducted a retrospective cohort study to investigate the geographical distribution of antimicrobial exposure among very preterm and very low birth weight infants in Japan.

STUDY DESIGN

We utilized a nationwide claims database in Japan to extract prescriptions of injectable antimicrobials for 41,423 very preterm and very low birth weight infants admitted within the first two days of life from April 2010 to March 2021. We identified frequently prescribed antimicrobials, revealed early neonatal exposure and neonatal exposure to each antimicrobial agent by 47 prefectures in Japan, and evaluated their spatial autocorrelation using global and local Moran's I statistics. We then scrutinized regional disparities in antimicrobial drug prescriptions.

RESULTS

The top 10 antimicrobials prescribed to very preterm and very low birth weight infants in Japan were ampicillin, amikacin, gentamicin, cefotaxime, fluconazole, ampicillin combination, micafungin, cefmetazole, cefazolin, and vancomycin. We identified northern cold spots for fluconazole exposure and southern hot spots for ampicillin, amikacin, gentamicin, and cefmetazole exposure. Geographical heterogeneity in the selection of antibacterial and antimycotic agents was observed.

CONCLUSION

Our study revealed the geographical distribution of antimicrobial exposure among very preterm and very low birth weight infants in Japan, thus disclosing its spatial effects. Further research addressing the spatial effects of neonatal care is needed to understand how drug exposure affects the outcomes of preterm infants.

Buy-in and breakthroughs: the Overton window in neonatology for the resuscitation of extremely preterm infants

To understand the future of neonatology, it is important to reflect upon the past and the factors that lead to significant advances in the field. In this article, we explore the evolving landscape of neonatology and the shifting practices in the resuscitation of extremely premature infants, with a particular focus on societal influences that have driven these changes. Using the political policy concept of an Overton Window, we explore how breakthroughs move from unthinkable to acceptable practice and how the increasing involvement of parents and their advocacy efforts have played a pivotal role in that progress. In the era of expanded shared decision making, it is crucial that we apply that same approach to setting priorities in our field, acknowledging the crucial perspectives of both parents and former premature infants in shaping the future of neonatology.

[Changes in neonatal care : Implications for ophthalmological care]

BACKGROUND

Preterm infants are at risk of characteristic, sometimes life-threatening diseases and development of deficits related to immaturity. In the field of ophthalmology, retinopathy of prematurity (ROP) and vision impairment reflect structural and functional disturbances in this large group of patients. In high income countries, more and more very immature preterm infants survive into adolescence and adulthood.

OBJECTIVE

To characterize the impact of an increasing number of surviving individuals born preterm on the provision of ophthalmological care in Germany.

MATERIAL AND METHODS

A literature search and analysis of key figures and quality indicators published in national health registers were carried out.

RESULTS

Currently, about 60,000 preterm infants are born in Germany every year. Of these, approximately 3600 extremely immature preterm infants with a gestational age < 28 weeks are treated with a curative approach on neonatal units. The survival rate is around 80%. A rise in the proportion of infants suffering from severe ROP has not been observed in recent years in Germany. The incidences of other structural and functional visual impairments vary between 3% and 25% in high income countries.

CONCLUSION

The incidence of ROP apparently has not increased in Germany. However, specific peculiarities of the structure and function of the visual system of individuals born preterm have to be taken into account. Approximately 70,000 outpatient check-ups of infants and toddlers, who require both, ophthalmological and developmental neurological expertise, are estimated for Germany each year.

Efficacy of perinatal pharmacotherapeutic actions for survival of very preterm newborn rabbits at 26-day gestation

Investigation of the pathophysiology of lung impairment and protection in very preterm neonates at birth requires adequate experimental models. This study aimed to elucidate the efficacy and mechanism of perinatal pharmacotherapeutic action in postnatal survival of very preterm rabbits. Pregnant New Zealand White rabbits on 25-day gestation (term 31 days) were given dexamethasone (D), or sham injection as control (C), and cesarean delivered 24 hours later on day 26. Newborns were anesthetized, intratracheally intubated, randomly received either saline or porcine surfactant (S), allocated to four groups (C, S, D, and DS), and ventilated with low tidal volume. Under the identical protocol, another four groups were added with nitric oxide (N) inhalation (CN, SN, DN, and DSN). Survival length, lung mechanics, histopathology, and pathobiology of lung tissue were measured for benefits and injury patterns. DSN had the longest median survival time (ST50, 10.3 h), whereas C had the shortest (3.5 h), with remaining groups in-between. The survival was mainly benefited by S, when additive effects with D and/or N were discernible, by improved lung mechanics and alveolar aeration, ameliorated lung injury severity and pneumothorax, and augmented lung phospholipid pools, with DSN being the most optimal. Variable mRNA expression profiles of alveolar epithelia-associated cytokines and inflammatory mediators further characterized injury and response patterns as phenotyping conditioned in pharmacotherapeutic actions. In conclusion, the combined regimens of perinatal medications achieved remarkable survival in very preterm rabbits with lung protective ventilation strategy, offering a unique model in investigation of very preterm birth-associated respiratory physiology and morbidities.NEW & NOTEWORTHY By establishing a very preterm rabbit model with 26-day gestation (term 31 days), optimal survival length for 50% of animals in groups was achieved by comparing regimens of combined antenatal glucocorticoids, postnatal surfactant and inhaled nitric oxide, with a low tidal volume ventilation strategy. The efficacies of pharmacotherapeutic action were associated with significantly improved lung mechanics, ameliorated lung injury and pneumothorax, and enhanced surfactant phospholipid metabolism, along with variable mRNA expression profiles characterizing the response patterns.

[Efficacy of volume-targeted ventilation versus high-frequency oscillatory ventilation in the treatment of neonatal respiratory distress syndrome]

OBJECTIVES

To study the clinical efficacy of volume-targeted ventilation (VTV) versus high-frequency oscillatory ventilation (HFOV) in the treatment of neonatal respiratory distress syndrome (NRDS).

METHODS

A retrospective cohort analysis was performed on the medical data of 140 neonates with severe NRDS who were admitted from September 2016 to February 2022, with 55 neonates in the VTV group and 85 in the HFOV group. The neonates in the VTV group received conventional mechanical ventilation and target tidal volume, and those in the HFOV group received HFOV. Arterial blood gas parameters were collected at 48 hours after admission, and related indices during hospitalization were recorded, including mortality rate, duration of invasive mechanical ventilation, duration of oxygen therapy, and the incidence rates of complications.

RESULTS

Compared with the VTV group, the HFOV group had significantly lower incidence rates of grade Ⅲ-Ⅳ periventricular-intraventricular hemorrhage and neonatal necrotizing enterocolitis (P<0.05), and there were no significant differences between the two groups in the duration of invasive mechanical ventilation, the duration of oxygen therapy, mortality rate, and the incidence rates of bronchopulmonary dysplasia, hypocapnia, hypercapnia, periventricular leukomalacia, and retinopathy of prematurity (P>0.05).

CONCLUSIONS

HFOV has a better clinical efficacy than VTV in the treatment of NRDS.

Regular lung recruitment maneuvers during high-frequency oscillatory ventilation in extremely preterm infants: a randomized controlled trial

BACKGROUND

Lung recruitment maneuvers (LRMs) improve lung volume at initiation of high-frequency oscillatory ventilation (HFOV), but it is unclear when to repeat LRMs. We evaluated the efficiency of scheduled LRMs.

METHODS

In a randomized controlled trial, extremely preterm infants on HFOV received either LRMs at 12-hour intervals and when clinically indicated (intervention) or only when clinically indicated (control). The primary outcome was the cumulative oxygen saturation index (OSI) over HFOV time, limited to 7 days. Additionally, LRMs were analyzed with respect to OSI improvement.

RESULTS

Fifteen infants were included in each group. The mean (SD) postmenstrual age and weight at HFOV start were 23 + 6 (0 + 5) weeks and 650 (115) g in the intervention group and 24 + 4 (0 + 6) weeks (p = 0.03) and 615 (95) g (p = 0.38) in the control group. The mean (SD) cumulative OSI amounted to 4.95 (1.72) in the intervention versus 5.30 (2.08) in the control group (p = 0.61). The mean (SD) number of LRMs in 12 h was 1.3 (0.2) in the intervention versus 1.1 (0.5) in the control group (p = 0.13). Performing LRM when FiO2 > 0.6 resulted in a mean OSI reduction of 3.6.

CONCLUSION

Regular versus clinically indicated LRMs were performed with equal frequency in preterm infants during HFOV, and consequently, no difference in lung volume was observed. LRMs seem to be most efficient at high FiO2.

TRIAL REGISTRATION

ClinicalTrials.gov ID: NCT04289324 (28/02/2020).

Ventilator Management in Extremely Preterm Infants

Advances in ventilation strategies for infants in the NICU have led to increased survival of extremely preterm infants. More than 75% of infants born at less than or equal to 27 weeks' gestation require initial mechanical ventilation for survival due to developmental immaturity of their lungs and respiratory drive. Various ventilators using different technologies and involving multiple management strategies are available for use in this population. Centers across the world have successfully used conventional, high-frequency oscillatory and high-frequency jet ventilation to manage respiratory failure in extremely preterm infants. This review explores the existing evidence for each mode of ventilation and the importance of individualizing ventilator management strategies when caring for extremely preterm infants.

Mechanical properties of the premature lung: From tissue deformation under load to mechanosensitivity of alveolar cells

Many preterm infants require mechanical ventilation as life-saving therapy. However, ventilation-induced overpressure can result in lung diseases. Considering the lung as a viscoelastic material, positive pressure inside the lung results in increased hydrostatic pressure and tissue compression. To elucidate the effect of positive pressure on lung tissue mechanics and cell behavior, we mimic the effect of overpressure by employing an uniaxial load onto fetal and adult rat lungs with different deformation rates. Additionally, tissue expansion during tidal breathing due to a negative intrathoracic pressure was addressed by uniaxial tension. We found a hyperelastic deformation behavior of fetal tissues under compression and tension with a remarkable strain stiffening. In contrast, adult lungs exhibited a similar response only during compression. Young’s moduli were always larger during tension compared to compression, while only during compression a strong deformation-rate dependency was found. In fact, fetal lung tissue under compression showed clear viscoelastic features even for small strains. Thus, we propose that the fetal lung is much more vulnerable during inflation by mechanical ventilation compared to normal inspiration. Electrophysiological experiments with different hydrostatic pressure gradients acting on primary fetal distal lung epithelial cells revealed that the activity of the epithelial sodium channel (ENaC) and the sodium-potassium pump (Na,K-ATPase) dropped during pressures of 30 cmH₂O. Thus, pressures used during mechanical ventilation might impair alveolar fluid clearance important for normal lung function.

Outcomes after neonatal cardiac surgery: The impact of a dedicated neonatal cardiac program

OBJECTIVES

Prematurity is a risk factor for in-hospital mortality after cardiac surgery. The structure of intensive care unit models designed to deliver optimal care to neonates including those born preterm with critical congenital heart disease is unknown. The objective of this study was to evaluate in-hospital outcomes after cardiac surgery across gestational ages in an institution with a dedicated neonatal cardiac program.

METHODS

This study is a single-center, retrospective review of infants who underwent cardiac surgical interventions from our dedicated neonatal cardiac intensive care program between 2006 and 2017. We evaluated in-hospital mortality and morbidity rates across all gestational ages.

RESULTS

A total of 1238 subjects met inclusion criteria over a 11-year period. Overall in-hospital mortality after cardiac surgery was 6.1%. The mortality rate in very preterm infants (n = 68; <34 weeks' gestation at birth) was 17.6% (odds ratio, 3.52 [1.4-8.53]), versus 4.3% in full-term (n = 563; 39-40 weeks) referent/control infants. Very preterm infants with isolated congenital heart disease (without evidence of other affected organ systems) experienced a mortality rate of 10.5% after cardiac surgery. Neither the late preterm (34-36 ^6/7 weeks) nor the early term (37-38 ^6/7) groups had significantly increased odds of mortality compared with full-term infants. Seventy-eight percent of very preterm infants incurred a preoperative or postoperative complication (odds ratio, 4.78 [2.61-8.97]) compared with 35% of full-term infants.

CONCLUSIONS

In this study of a single center with a dedicated neonatal cardiac program, we report some of the lowest mortality and morbidity rates after cardiac surgery in preterm infants in the recent era. The potential survival advantage of this model is most striking for very preterm infants born with isolated congenital heart disease.

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

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

Lung Protection During Mechanical Ventilation in the Premature Infant

Mechanical ventilation can be life-saving for the premature infant, but is often injurious to immature and underdeveloped lungs. Lung injury is caused by atelectrauma, oxygen toxicity, and volutrauma. Lung protection must include appropriate lung recruitment starting in the delivery suite and throughout mechanical ventilation. Strategies include open lung ventilation, positive end-expiratory pressure, and volume-targeted ventilation. Respiratory function monitoring, such as capnography and ventilator graphics, provides clinicians with continuous real-time information and an adjunct to optimize lung-protective ventilatory strategies. Further research is needed to assess which lung-protective strategies result in a decrease in long-term respiratory morbidity.

Bronchopulmonary dysplasia-A historical perspective

Bronchopulmonary dysplasia (BPD) was first described by Northway et al in 1967. This article describes the evolution of our understanding of the pathophysiology of BPD and the approaches to treatments of this illness developed over the past fifty years. These interventions had their roots in the understanding of the principles of the surface tension present at air-liquid interfaces, which were developed over 150 years before BPD's initial description. Improving outcomes in neonatal care have led to greater survival of preterm and very preterm infants, and to an evolution of the pathogenesis and pathology of BPD, from an illness caused primarily by barotrauma and oxygen toxicity to one of interruption of lung development. While the incidence of BPD has remained about the same in recent decades, this is because survival of infants born at lower gestational ages is increasing. Understanding of molecular, genetic and physiologic mechanisms has led to newer treatments that have mitigated some of the harmful effects of prolonged mechanical ventilation. Recognition of BPD as a chronic multi-system disease has resulted in further improvements in care after discharge from neonatal intensive care. Since many of the origins of chronic obstructive lung disease in adults are based in childhood respiratory illnesses, improving outcomes of BPD in infancy and childhood will undoubtedly lead to improved respiratory outcomes in the adults that these children will become.

Efficacy of continuous positive airway pressure in neonates with respiratory distress syndrome: A protocol for systematic review and meta-analysis

BACKGROUND

Respiratory distress syndrome (RDS) is a condition caused by a deficiency in pulmonary surfactant. Many interventions, including pulmonary surfactant, non-invasive respiratory support, and other supportive treatments have been used to prevent RDS. However, recent studies have focused on the continuous positive airway pressure as a significant potential agent for preventing RDS. However, its safety and effectiveness are yet to be assessed. To this end, the current study aims to perform to explore the safety and effectiveness of continuous positive airways in treating neonates with RDS.

METHODS

We will conduct comprehensive literature searches on MEDLINE, Cochrane Library, EMBASE, Chinese National Knowledge Infrastructure, and Chinese BioMedical Literature from their inception to April 2021. The search aims to identify all the randomized controlled studies on continuous positive airway pressure in treating neonates with RDS. In addition, we aim to search the gray literature to establish any available potential studies. We will use 2 independent authors to determine study eligibility, extract data using the structured pro-forma table, analyze data, and utilize suitable tools in assessing the risk of bias in the selected studies. Accordingly, we will conduct all statistical analyses using RevMan 5.3 software.

RESULTS

The current study aims to provide high-quality synthesis of existing evidence concerning the continuous positive airway pressure to treat neonates suffering from RDS.

CONCLUSION

Our findings seek to provide evidence to establish whether continuous positive airway pressure can ascertain safety and effectiveness for neonates with RDS.

ETHICS AND DISSEMINATION

The study will require ethical approval.

OSF REGISTRATION NUMBER

May 20, 2021.osf.io/7nj8s. (https://osf.io/7nj8s/).

Surfactant therapy via thin catheter in preterm infants with or at risk of respiratory distress syndrome

BACKGROUND

Non-invasive respiratory support is increasingly used for the management of respiratory dysfunction in preterm infants. This approach runs the risk of under-treating those with respiratory distress syndrome (RDS), for whom surfactant administration is of paramount importance. Several techniques of minimally invasive surfactant therapy have been described. This review focuses on surfactant administration to spontaneously breathing infants via a thin catheter briefly inserted into the trachea.

OBJECTIVES

Primary objectives In non-intubated preterm infants with established RDS or at risk of developing RDS to compare surfactant administration via thin catheter with: 1. intubation and surfactant administration through an endotracheal tube (ETT); or 2. continuation of non-invasive respiratory support without surfactant administration or intubation. Secondary objective 1. To compare different methods of surfactant administration via thin catheter Planned subgroup analyses included gestational age, timing of intervention, and use of sedating pre-medication during the intervention.

SEARCH METHODS

We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL), in the Cochrane Library; Ovid MEDLINE(R) and Epub Ahead of Print, In-Process & Other Non-Indexed Citations, Daily and Versions(R); and the Cumulative Index to Nursing and Allied Health Literature (CINAHL), on 30 September 2020. We also searched clinical trials databases and the reference lists of retrieved articles for randomised controlled trials (RCTs) and quasi-randomised trials.

SELECTION CRITERIA

We included randomised trials comparing surfactant administration via thin catheter (S-TC) with (1) surfactant administration through an ETT (S-ETT), or (2) continuation of non-invasive respiratory support without surfactant administration or intubation. We also included trials comparing different methods/strategies of surfactant administration via thin catheter. We included preterm infants (at < 37 weeks' gestation) with or at risk of RDS.

DATA COLLECTION AND ANALYSIS

Review authors independently assessed study quality and risk of bias and extracted data. Authors of all studies were contacted regarding study design and/or missing or unpublished data. We used the GRADE approach to assess the certainty of evidence.

MAIN RESULTS

We included 16 studies (18 publications; 2164 neonates) in this review. These studies compared surfactant administration via thin catheter with surfactant administration through an ETT with early extubation (Intubate, Surfactant, Extubate technique - InSurE) (12 studies) or with delayed extubation (2 studies), or with continuation of continuous positive airway pressure (CPAP) and rescue surfactant administration at pre-specified criteria (1 study), or compared different strategies of surfactant administration via thin catheter (1 study). Two trials reported neurosensory outcomes of of surviving participants at two years of age. Eight studies were of moderate certainty with low risk of bias, and eight studies were of lower certainty with unclear risk of bias. S-TC versus S-ETT in preterm infants with or at risk of RDS Meta-analyses of 14 studies in which S-TC was compared with S-ETT as a control demonstrated a significant decrease in risk of the composite outcome of death or bronchopulmonary dysplasia (BPD) at 36 weeks' postmenstrual age (risk ratio (RR) 0.59, 95% confidence interval (CI) 0.48 to 0.73; risk difference (RD) -0.11, 95% CI -0.15 to -0.07; number needed to treat for an additional beneficial outcome (NNTB) 9, 95% CI 7 to 16; 10 studies; 1324 infants; moderate-certainty evidence); the need for intubation within 72 hours (RR 0.63, 95% CI 0.54 to 0.74; RD -0.14, 95% CI -0.18 to -0.09; NNTB 8, 95% CI; 6 to 12; 12 studies, 1422 infants; moderate-certainty evidence); severe intraventricular haemorrhage (RR 0.63, 95% CI 0.42 to 0.96; RD -0.04, 95% CI -0.08 to -0.00; NNTB 22, 95% CI 12 to 193; 5 studies, 857 infants; low-certainty evidence); death during first hospitalisation (RR 0.63, 95% CI 0.47 to 0.84; RD -0.02, 95% CI -0.10 to 0.06; NNTB 20, 95% CI 12 to 58; 11 studies, 1424 infants; low-certainty evidence); and BPD among survivors (RR 0.57, 95% CI 0.45 to 0.74; RD -0.08, 95% CI -0.11 to -0.04; NNTB 13, 95% CI 9 to 24; 11 studies, 1567 infants; moderate-certainty evidence). There was no significant difference in risk of air leak requiring drainage (RR 0.58, 95% CI 0.33 to 1.02; RD -0.03, 95% CI -0.05 to 0.00; 6 studies, 1036 infants; low-certainty evidence). None of the studies reported on the outcome of death or survival with neurosensory disability. Only one trial compared surfactant delivery via thin catheter with continuation of CPAP, and one trial compared different strategies of surfactant delivery via thin catheter, precluding meta-analysis.

AUTHORS' CONCLUSIONS

Administration of surfactant via thin catheter compared with administration via an ETT is associated with reduced risk of death or BPD, less intubation in the first 72 hours, and reduced incidence of major complications and in-hospital mortality. This procedure had a similar rate of adverse effects as surfactant administration through an ETT. Data suggest that treatment with surfactant via thin catheter may be preferable to surfactant therapy by ETT. Further well-designed studies of adequate size and power, as well as ongoing studies, will help confirm and refine these findings, clarify whether surfactant therapy via thin tracheal catheter provides benefits over continuation of non-invasive respiratory support without surfactant, address uncertainties within important subgroups, and clarify the role of sedation.

Respiratory Syncytial Virus Immunoprophylaxis with Palivizumab: 12-Year Observational Study of Usage and Outcomes in Canada

OBJECTIVE

This study aimed to evaluate palivizumab (PVZ) use, trends in indications, and outcomes of respiratory illness hospitalizations (RIH) and respiratory syncytial virus hospitalizations (RSVH).

STUDY DESIGN

It involves a large, Canadian prospective (2005-2017) observational multicenter study of children at high risk for RSV infection.

RESULTS

A total of 25,003 infants (56.3% male) were enrolled at 32 sites; 109,579 PVZ injections were administered. Indications included: prematurity (63.3%); "miscellaneous" (17.8%); hemodynamically significant congenital heart disease (10.5%); bronchopulmonary dysplasia/chronic lung disease (8.4%). The "miscellaneous" group increased over time (4.4% in 2005-2006 to 22.5% in 2016-2017) and included: trisomy 21, airway anomalies, pulmonary disorders, cystic fibrosis, neurological impairments, immunocompromised, cardiac aged >2 years, multiple conditions, and a residual "unclassified" group. Adherence measured by expected versus actual doses plus correct interdose interval was 64.7%. A total of 2,054 RIH occurred (6.9%); 198 (9.6%) required intubation. Three hundred thirty-seven hospitalized children were RSV-positive (overall RSVH 1.6%). Risk factors for RSVH included having siblings, attending daycare, family history of atopy, smoking exposure, and crowded household. Infants with 5 risk factors were 9.0 times (95% CI or confidence interval 4.4-18.2; p < 0.0005) more likely to have RSVH than infants without risk factors. Three adverse events occurred; none were fatal.

CONCLUSION

Results are relevant to both clinicians and decision-makers. We confirmed the safety of PVZ. Use of PVZ increased steadily for children with miscellaneous conditions and medical complexity. Medical and social factors pose a risk for severe RIH and RSVH with accompanying burden of illness. A vaccine that protects against RSV is urgently required.

KEY POINTS

· Main indications were prematurity (63.3%); "miscellaneous" (17.8%); hemodynamically significant congenital heart disease (10.5%); bronchopulmonary dysplasia/chronic lung disease (8.4%).. · The proportion of children in the "miscellaneous" group, comprised of those with trisomy 21, airway anomalies, pulmonary disorders, cystic fibrosis, neurological impairments, immunocompromised, cardiac aged >2 years, multiple conditions, and a residual "unclassified" group, increased over time (4.4% in 2005-2006 to 22.5% in 2016-2017).. · Respiratory illness-related hospitalization occurred in 2,054 children (6.9%); 198 (9.6%) required intubation. Three hundred thirty-seven hospitalized children were RSV-positive (overall RSVH: 1.6%)..

SHORT-TERM OUTCOME OF MASSIVE PULMONARY HEMORRHAGE IN PRETERM INFANTS IN TUZLA CANTON

Massive pulmonary hemorrhage (MPH) in neonates is a severe condition followed by many complications and associated with a high mortality rate. The aim of this study was to present the incidence, possible risk factors, and short-term outcome of neonatal MPH in Tuzla Canton. We retrospectively analyzed data on neonates with MPH from January 2015 to December 2017. On statistical analysis, standard methods of descriptive statistics were used. During the three-year study period, 16 neonates developed MPH, 5 (31.25%) male and 11 (68.75%) female. Their mean gestational age was 29.48±2.21 weeks and mean birth weight 1276.69±387.65 grams. Seven (43.75%) neonates survived and 9 (56.25%) died. Significant differences between the two outcome groups (survivors/died) were found in gestational age, birth weight, birth length, 5-minute Apgar score, and length of treatment at the Neonatal Intensive Care Unit. In Tuzla Canton, MPH occurred mainly in preterm neonates requiring mechanical ventilation, with the incidence of 1.91% of total premature births. The short-term outcome was uncertain, with a high mortality rate of 56.25%. Lower gestational age, lower birth weight, lower birth length and lower 5-minute Apgar score were confirmed as risk factors for poor short-term outcome.

Bubble Nasal Continuous Positive Airway Pressure (bNCPAP): An Effective Low-Cost Intervention for Resource-Constrained Settings

Preterm birth complications are responsible for almost one-third of the global neonatal mortality burden, and respiratory distress syndrome remains the single most common cause of these preventable deaths. Since its inception, almost half a century ago, nasal continuous positive airway pressure (NCPAP) has evolved to become the primary modality for neonatal respiratory care in both the developed and developing world. Although evidence has demonstrated the effectiveness of low-cost bubble NCPAP in reducing newborn mortality, its widespread use is yet to be seen in resource-constrained settings. Moreover, many tertiary hospitals in developing countries still utilise an inexpensive locally assembled bNCPAP system of unknown efficacy and safety. This review provides a brief overview of the history, physiological benefits, indications, contraindications, and complications of bNCPAP. Evidence regarding the effectiveness of low-cost bNCPAP in the neonatal intensive care unit is also summarised. The article further details a locally assembled bNCPAP system used in resource-constrained settings and highlights the care package for neonates receiving bNCPAP, failure criteria, and strategies for weaning.

Association Between Preterm Birth and Arrested Cardiac Growth in Adolescents and Young Adults

Importance

Premature birth is associated with substantially higher lifetime risk for cardiovascular disease, including arrhythmia, ischemic disease, and heart failure, although the underlying mechanisms are poorly understood.

Objective

To characterize cardiac structure and function in adolescents and young adults born preterm using cardiac magnetic resonance imaging (MRI).

Design, Setting, and Participants

This cross-sectional cohort study at an academic medical center included adolescents and young adults born moderately to extremely premature (20 in the adolescent cohort born from 2003 to 2004 and 38 in the young adult cohort born in the 1980s and 1990s) and 52 age-matched participants who were born at term and underwent cardiac MRI. The dates of analysis were February 2016 to October 2019.

Exposures

Premature birth (gestational age ≤32 weeks) or birth weight less than 1500 g.

Main Outcomes and Measures

Main study outcomes included MRI measures of biventricular volume, mass, and strain.

Results

Of 40 adolescents (24 [60%] girls), the mean (SD) age of participants in the term and preterm groups was 13.3 (0.7) years and 13.0 (0.7) years, respectively. Of 70 adults (43 [61%] women), the mean (SD) age of participants in the term and preterm groups was 25.4 (2.9) years and 26.5 (3.5) years, respectively. Participants from both age cohorts who were born prematurely had statistically significantly smaller biventricular cardiac chamber size compared with participants in the term group: the mean (SD) left ventricular end-diastolic volume index was 72 (7) vs 80 (9) and 80 (10) vs 92 (15) mL/m2 for adolescents and adults in the preterm group compared with age-matched participants in the term group, respectively (P < .001), and the mean (SD) left ventricular end-systolic volume index was 30 (4) vs 34 (6) and 32 (7) vs 38 (8) mL/m2, respectively (P < .001). Stroke volume index was also reduced in adolescent vs adult participants in the preterm group vs age-matched participants in the term group, with a mean (SD) of 42 (7) vs 46 (7) and 48 (7) vs 54 (9) mL/m2, respectively (P < .001), although biventricular ejection fractions were preserved. Biventricular mass was statistically significantly lower in adolescents and adults born preterm: the mean (SD) left ventricular mass index was 39.6 (5.9) vs 44.4 (7.5) and 40.7 (7.3) vs 49.8 (14.0), respectively (P < .001). Cardiac strain analyses demonstrated a hypercontractile heart, primarily in the right ventricle, in adults born prematurely.

Conclusions and Relevance

In this cross-sectional study, adolescents and young adults born prematurely had statistically significantly smaller biventricular cardiac chamber size and decreased cardiac mass. Although function was preserved in both age groups, these morphologic differences may be associated with elevated lifetime cardiovascular disease risk after premature birth.

Availability and use of continuous positive airway pressure (CPAP) for neonatal care in public health facilities in India: a cross-sectional cluster survey

OBJECTIVES

To determine the availability of continuous positive airway pressure (CPAP) and to provide an overview of its use in neonatal units in government hospitals across India.

SETTING

Cross-sectional cluster survey of a nationally representative sample of government hospitals from across India.

PRIMARY OUTCOMES

Availability of CPAP in neonatal units.

SECONDARY OUTCOMES

Proportion of hospitals where infrastructure and processes to provide CPAP are available. Case fatality rates and complication rates of neonates treated with CPAP.

RESULTS

Among 661 of 694 government hospitals with neonatal units that provided information on availability of CPAP for neonatal care, 68.3% of medical college hospitals (MCH) and 36.6% of district hospitals (DH) used CPAP in neonates. Assessment of a representative sample of 142 hospitals (79 MCH and 63 DH) showed that air-oxygen blenders were available in 50.7% (95% CI 41.4% to 60.9%) and staff trained in the use of CPAP were present in 56.0% (45.8% to 65.8%) of hospitals. The nurse to patient ratio was 7.3 (6.4 to 8.5) in MCH and 6.6 (5.5 to 8.3) in DH. Clinical guidelines were available in 31.0% of hospitals (22.2% to 41.4%). Upper oxygen saturation limits of above 94% were used in 72% (59.8% to 81.6%) of MCH and 59.3% (44.6% to 72.5%) of DH. Respiratory circuits were reused in 53.8% (42.3% to 63.9%) of hospitals. Case fatality rate for neonates treated with CPAP was 21.4% (16.6% to 26.2%); complication rates were 0.7% (0.2% to 1.2%) for pneumothorax, 7.4% (0.9% to 13.9%) for retinopathy and 1.4% (0.7% to 2.1%) for bronchopulmonary dysplasia.

CONCLUSIONS

CPAP is used in neonatal units across government hospitals in India. Neonates may be overexposed to oxygen as the means to detect and treat consequences of oxygen toxicity are insufficient. Neonates may also be exposed to nosocomial infections by reuse of disposables. Case fatality rates for neonates receiving CPAP are high. Complications might be under-reported. Support to infrastructure, training, guidelines implementation and staffing are needed to improve CPAP use.

Effect of a new respiratory care bundle on bronchopulmonary dysplasia in preterm neonates

The development of devices that can fix the tidal volume in high-frequency oscillatory ventilation (HFOV) has allowed for a significant improvement in the management of HFOV. At our institution, this had led to the earlier use of HFOV and promoted a change in the treatment strategy involving the use of higher frequencies (above 15 Hz) and lower high-frequency tidal volumes (VThf). The purpose of this observational study was to assess how survival without bronchopulmonary dysplasia grades 2 and 3 (SF-BPD) is influenced by these modifications in the respiratory strategy applied to preterm infants (gestational age < 32 weeks at birth) who required mechanical ventilation (MV) in the first 3 days of life. We compared a baseline period (2012-2013) against a period in which this strategy had been fully implemented (2016-2017). A total of 182 patients were exposed to MV in the first 3 days of life being a higher proportion on HFOV at day 3 in the second period 79.5% (n 35) in 2016-2017 vs 55.4% (n 31) in 2012-2013. After adjusting for perinatal risk factors, the second period is associated with an increased rate of SF-BPD (OR 2.28; CI 95% 1.072-4.878); this effect is more evident in neonates born at a gestational age of less than 29 weeks (OR 4.87; 95% CI 1.9-12.48).Conclusions : The early use of HFOV combined with the use of higher frequencies and very low VT was associated with an increase in the study population's SF-BPD. What is Known: • High-frequency ventilation with volume guarantee improve ventilation stability and has been shown to reduce lung damage in animal models. What is New: • The strategy of an earlier use of high-frequency oscillatory ventilation combined with the use of higher frequencies and lower tidal volume is associated to an increase in survival without bronchopulmonary dysplasia in our population of preterm infants.

Bronchopulmonary dysplasia: Rationale for a pathophysiological rather than treatment based approach to diagnosis

Bronchopulmonary dysplasia (BPD), also known as Chronic Lung Disease (CLD), is a chronic respiratory condition of prematurity with potential life-long consequences for respiratory well-being. BPD was first described by Northway in 1967, when the mean gestation of preterm infants with BPD was 34 weeks' postmenstrual age (PMA). Survival of preterm infants at lower gestational ages has increased steadily since 1967 associated with marked improvements in respiratory management of respiratory distress syndrome. Currently, BPD develops in approximately 45 % of all infants born extremely preterm (Stoll et al., 2015). These smaller and more immature babies are born during the late canalicular or early saccular period of lung development. Not surprisingly, the pathophysiology of BPD also evolved since classical BPD was described. As the nature and our understanding of BPD evolved, so too the definitions and classification of BPD changed over time. These differing and ever-changing definitions hamper clinical benchmarking as they are interpreted and applied inconsistently, and define BPD and its severity by non-standardised treatments rather than independent evaluations of structure or function. A standardised, unambiguous definition and classification of BPD is essential for evaluation and improvement in clinical practice, both within an individual unit, as well as across and between neonatal networks. The determination and implementation of diagnostic criteria and severity classification that is standardised, globally applicable, and that has prognostic utility for clinical outcomes and guidance of ongoing respiratory management remain of utmost importance. This review describes the evolution of BPD definitions, evaluates the benefits and limitations of each approach, and discusses alternative approaches that may improve the functional assessment of BPD severity.

Prone versus supine position for regional cerebral tissue oxygenation in preterm neonates receiving noninvasive ventilation

OBJECTIVE

The prone position was found to improve oxygenation and pulmonary functions in neonates receiving respiratory support. However, how this improvement changes brain tissue oxygenation has not been studied. We aimed to investigate how prone position effects regional cerebral oxygen saturation (rScO₂) and cerebral fractional oxygen extraction (FOE) in preterm neonates during noninvasive ventilation (NIV).

METHODS

Preterm neonates < 37 weeks gestational age (GA) stable on NIV were enrolled. NIV was defined as nasal continues positive airway pressure or intermittent positive pressure ventilation via binasal prongs. Near infrared spectroscopy was used to measure rScO₂. Monitoring was started when the infant was lying supine for at least 1 h and continued at the same body position at least for 1 h. Later the infant was changed to prone position and monitored for additional 3 h. Arterial oxygen saturation (SO₂) was also continuously monitored and FOE was calculated from rScO₂ and SO₂.

RESULTS

Mean GA and birth weight of the cohort (n = 32) were 30.63 ± 3.09 weeks and 1459 ± 581 g, respectively. There were 14 females and 18 males. Both SO₂ (95 ± 2.2% versus 96.2 ± 1.9%, p = .001) and rScO₂ (79.2 ± 3.4% versus 82.1 ± 3.2%, p < .001) were higher in prone position compared to supine position. Cerebral FOE (16.6 ± 0.8% versus 14.7 ± 0.8%, p < .001) and respiratory rate (57.3 ± 5.5 versus 55.6 ± 9.2, p = .003) were lower in prone position.

CONCLUSION

In preterm newborns, receiving nasal NIV for mild to moderate respiratory distress, arterial and cerebral oxygenations were better in prone position.

Prediction of prolonged ventilator dependence in preterm infants

Volutrauma is an important factor in the pathogenesis of bronchopulmonary dysplasia (BPD). Our aims were to identify risk factors in the first 24 h for prolonged ventilator dependence and assess volume delivery and carbon dioxide levels in infants with evolving BPD. A retrospective study was undertaken of 41 infants born at less than 32 weeks of gestational age (GA). A higher tidal volume, minute volume and resistance and a lower GA, birth weight and compliance were associated with a significantly higher risk of ventilator dependence at 28 days. The strongest relationships were with birth weight (area under the receiver operating characteristic curve, AUROC = 0.771) and GA (AUROC = 0.813). Tidal volume remained significantly higher after adjusting for GA in those who remained ventilator dependent at 28 days. The 18 who remained ventilator dependent at 28 days had increased mean carbon dioxide (PCO₂) levels with increasing age from a mean of 41 mmHg in the first 24 h to 65 mmHg at 28 days PMA (p < 0.001). The increase in PCO₂ occurred despite increases in peak inflation pressures (p < 0.001), tidal volumes (p = 0.002) and minute volumes (p < 0.001).Conclusion: These results suggest that initial volutrauma may contribute to the development of chronic ventilator dependence. What is Known: • In prematurely born infants, excessive tidal volumes are important in the pathogenesis of bronchopulmonary dysplasia (BPD), but a tidal volume that is too low will increase the risk of atelectasis, work of breathing and energy expenditure. What is New: • A high tidal volume in the first 24 h was associated with an increased risk of ventilator dependence at 28 days, which remained significant after adjusting for gestational age. Carbon dioxide levels significantly increased over the first month despite increased pressures and volumes in those who remained ventilator dependent.

Healthcare workers' views on the use of continuous positive airway pressure (CPAP) in neonates: a qualitative study in Andhra Pradesh, India

Background

Continuous Positive Airway Pressure (CPAP) is a form of non-invasive ventilatory support which is increasingly used in low- and middle-income countries to treat neonates with acute respiratory distress. However, it may be harmful if used incorrectly. We aimed to explore the experiences of doctors and nurses using CPAP in neonatal units in India and their views on enablers and barriers to implementation of CPAP.

Methods

Participants from 15 neonatal units across Andhra Pradesh were identified through purposive sampling. Eighteen in-depth interviews (IDI) with doctors and eight focus group discussions (FGD) with 51 nurses were conducted. Data were analysed thematically using the framework approach.

Results

Common structural factors that limit the use of CPAP include shortages of staff, consumables and equipment, and problems with regard to the organisation of neonatal units in both district hospitals and medical colleges. This meant that CPAP was often not available for babies who were identified to need CPAP, or that CPAP use was not perceived to be of the highest quality. Providing care under constrained circumstances left staff feeling powerless to provide good quality care for neonates with acute respiratory distress. Despite this, staff were enthusiastic about the use of CPAP and its potential to save lives. CPAP use was mostly perceived as technically easier to provide than ventilation and allowed nurses to provide advanced neonatal care, independently of doctors.

Conclusions

Doctors and nurses embraced CPAP use but identified barriers to implementation which will need to be addressed in order not to impact on safety and quality of care. Ensuring a supportive and enabling environment is in place will be crucial if CPAP is to be scaled-up more widely.

Electronic supplementary material

The online version of this article (10.1186/s12887-018-1311-8) contains supplementary material, which is available to authorized users.

Relationship between Epigenetic Maturity and Respiratory Morbidity in Preterm Infants

OBJECTIVE

To assess associations between epigenetic maturity of extremely preterm babies (born at less than 28 weeks of gestation), neonatal interventions, and respiratory outcomes, including the administration of surfactant and postnatal corticosteroids, duration of assisted ventilation, and development of bronchopulmonary dysplasia (BPD).

STUDY DESIGN

DNA was extracted from neonatal blood spots collected after birth from 143 extremely preterm infants born 1991-1992 in Victoria, Australia and used to determined DNA methylation (DNAm). A DNAm based gestational age was determined using our previously published method. The residual of DNAm gestational age and clinically estimated gestational age (referred to as "gestational age acceleration") was used as a measure to assess developmental maturity. Associations between gestational age acceleration and respiratory interventions and morbidities were determined.

RESULTS

Infants with higher gestational age acceleration were less likely to receive surfactant (P = .009) or postnatal corticosteroids (P = .008), had fewer days of assisted ventilation (P = .01), and had less BPD (P = .02). Respiratory measures are known to correlate with gestational age; however, models comparing each with clinically estimated gestational age were improved by the addition of the gestational age acceleration measure in the model.

CONCLUSIONS

Gestational age acceleration correlates with respiratory interventions and outcomes of extremely preterm babies. Surfactant and postnatal corticosteroid use, assisted ventilation days, and BPD rates were all lower in babies who were epigenetically more mature than their obstetrically estimated gestational age. This suggests that gestational age acceleration is a clinically relevant metric of developmental maturity.

Oxygen Saturation Index for assessment of respiratory failure in neonates

Introduction: Acute respiratory failure (ARF) is the most common problem seen in the preterm and term infants admitted to neonatal intensive care units. Etiology is not uniform, and mostly depend on gestational age. For adequate treatment is certainly important to recognize and treat underlying disease, but at the same time, we have to supply adequate respiratory support, tissue perfusion and oxygen deliveries. For a good outcome we need reliable estimation method for functional state of respiratory system, as well as monitoring the effects of treatment. Current assessment ARF is with blood gas, chest X-ray and Oxygenation index (OI). OI is quite aggressive assessment method for neonates, because it involves arterial blood sampling. Promoted in recent studies, Oxygen saturation index (OSI) measured by pulse oximetry, attempts to objectively score respiratory disease with parameters available non-invasively. The aim of our research is to evaluate correlation between OSI and OI in neonates with ARF requiring mechanical ventilation. Material and methods: In a retrospective cohort study 101 neonates were selected, treated at the Department of intensive therapy and care, Pediatric clinic of Tuzla, due to ARF requiring mechanical ventilation. We reviewed data such as gestational age, birth weight, gender, Apgar scores, values of Score for Neonatal Acute Physiology-Perinatal Extension, all the parameters from the arterial blood gas analysis, pulse oximetry values, Oxygenation Index and Oxygenation Saturation Index, that were calculated by the formulas. OSI and OI were calculated and correlated. Mean values of OSI and OI correlated with Pearson's coefficient of 0.76; p < 0.0001 (95% CI = 0.66-0.83). OSI correlated with SNAP-PE with Pearson's coefficient of 0.52; p < 0.0001 (95% CI = 0.36-0.65). Comparing the values of OSI between patients who died and those who survived, we found that OSI correlated with the outcome with Spearman's coefficient of -0.47; p < 0.0001 (95% CI = -0.16 - -0.31). Bland-Altman plot confirmed correlation between OSI and OI in mean values, identifying discrepancy between two indices for extreme values.In conclusion, OSI correlates significantly with OI in infants with respiratory failure. This noninvasive method of oxygenation assessment, utilizing pulse oximetry, can be used to assess the severity of ARF and mortality risk in neonates.

Lung-protective ventilatory strategies in intubated preterm neonates with RDS

This article provides a narrative review of lung-protective ventilatory strategies (LPVS) in intubated preterm infants with RDS. A description of strategies is followed by results on short-and long-term respiratory and neurodevelopmental outcomes. Strategies will include patient-triggered or synchronized ventilation, volume targeted ventilation, the technique of intubation, surfactant administration and rapid extubation to NCPAP (INSURE), the open lung concept, strategies of high-frequency ventilation, and permissive hypercapnia. Based on this review single recommendations on optimal LPVS cannot be made. Combinations of several strategies, individually applied, most probably minimize or avoid potential serious respiratory and cerebral complications like bronchopulmonary dysplasia and cerebral palsy.

Determinants of pulmonary dead space in ventilated newborn infants

BACKGROUND

Pulmonary dead space (V_D) is an index of ventilation inhomogeneity and one of the determinants of the magnitude of tidal volume to maintain optimal blood gases.

AIMS

To identify the determinants of V_D in ventilated newborns and to investigate differences in V_D between prematurely born and term infants and those prematurely born infants who did or did not develop bronchopulmonary dysplasia (BPD).

METHODS

Sixty-one mechanically ventilated infants (15 term, 46 preterm) were studied at a median age of 8 (IQR 2-31) days; 32 of the preterm infants developed BPD. V_D was determined from the difference between arterial and end tidal carbon dioxide (CO₂) using a low dead space CO₂ detector using the Bohr/Enghoff equation and was related to body weight (V_D/kg) at the time of study. The time to peak tidal expiratory flow/expiratory time (T_PTEF/T_E) was measured during spontaneous breathing using a fixed orifice pneumotachograph.

RESULTS

V_D/kg was related to gestational age (r=-0.285, p=0.001), birth weight (r=-0.356, p<0.001), weight (r=-0.316, p<0.001) and postmenstrual age (r=-0.205, p=0.020) at measurement, days of ventilation (r=0.322, p<0.001) and T_PTEF/T_E (r=-0.397, p=0.003). The median V_D/kg was higher in prematurely born infants [2.3 (IQR: 1.7-3.0) ml/kg] compared to term infants [1.5 (1.3-2.1) ml/kg, (p=0.003)] and in premature infants that developed BPD [2.6 (IQR 1.8-3.4) ml/kg] compared to those who did not [1.7 (IQR 1.1-1.9) ml/kg], (p<0.001).

CONCLUSIONS

Numerous factors influence pulmonary dead space and thus an optimum tidal volume will differ according to the underlying demographics and respiratory status.

Congenital diaphragmatic hernia: outcomes of neonates treated at Mayo Clinic with and without extracorporeal membrane oxygenation

BACKGROUND

Congenital diaphragmatic hernia (CDH) is a rare anomaly with high mortality and long-term comorbid conditions.

AIMS

Our aim was to describe the presenting characteristics, treatment, and outcomes of consecutive patients with CDH treated at our institution.

METHODS

We performed a retrospective cohort study and identified consecutive neonates treated for CDH from 2001 to 2015 at our institution. For all patients identified, we reviewed hospital and postdischarge data for neonatal, disease, and treatment characteristics. We determined hospital survival overall and also according to the presence of prenatal diagnosis, liver herniation into the chest (liver up), and the use of extracorporeal membrane oxygenation (ECMO) in addition to surgery. We evaluated postdischarge chronic conditions in patients with at least one year of follow-up.

RESULTS

Thirty-eight neonates were admitted for treatment during the study period. In three who were in extremis, life support was withdrawn. The other 35 underwent surgical repair, of whom eight received ECMO. The overall survival was 79% (30/38). Survival for those who had surgical correction of CDH but did not need ECMO was 89% (24/27); it was 75% (6/8) for those who received ECMO and had surgery. Hospital survival was lower for liver-up vs liver-down CDH (61% [11/18] vs 95% [19/20]; odds ratio, 0.08; 95% CI, 0.01-0.77; P = 0.01). Among survivors, the median duration of hospitalization was 31 (interquartile range, 20-73) days. Major chronic pulmonary and gastrointestinal disorders, failure to thrive, and neurodevelopmental delays were the most noted comorbid conditions after discharge, and all were more prevalent in those who required ECMO.

CONCLUSION

The overall survival of neonates with CDH was 79%. Intrathoracic liver herniation was associated with more frequent use of ECMO and greater mortality. A substantial number of survivors, especially those who required ECMO, experienced chronic conditions after discharge.

Continuous positive airway pressure (CPAP) to treat respiratory distress in newborns in low- and middle-income countries

Severe respiratory distress is a serious complication common to the three major causes of neonatal mortality and morbidity (prematurity, intra-partum-related hypoxia and infections). In low- and middle-income countries (LMICs), 20% of babies presenting with severe respiratory distress die.Continuous positive airway pressure (CPAP), is an effective intervention for respiratory distress in newborns and widely used in high-income countries. Following the development of simple, safe and relatively inexpensive CPAP devices, there is potential for large-scale implementation in the developing world.In this article, we describe existing CPAP systems and present a review of the current literature examining the effectiveness of CPAP compared to standard care (oxygen) in newborns with respiratory distress. We also discuss the evidence gap which needs to be addressed prior to its integration into health systems in LMICs.

Noninvasive Respiratory Support

Mechanical ventilation is associated with increased survival of preterm infants but is also associated with an increased incidence of chronic lung disease (bronchopulmonary dysplasia) in survivors. Nasal continuous positive airway pressure (nCPAP) is a form of noninvasive ventilation that reduces the need for mechanical ventilation and decreases the combined outcome of death or bronchopulmonary dysplasia. Other modes of noninvasive ventilation, including nasal intermittent positive pressure ventilation, biphasic positive airway pressure, and high-flow nasal cannula, have recently been introduced into the NICU setting as potential alternatives to mechanical ventilation or nCPAP. Randomized controlled trials suggest that these newer modalities may be effective alternatives to nCPAP and may offer some advantages over nCPAP, but efficacy and safety data are limited.

Neonatal anesthesia: how we manage our most vulnerable patients

Neonates undergoing surgery are at higher risk than older children for anesthesia-related adverse events. During the perioperative period, the maintenance of optimal hemodynamics in these patients is challenging and requires a thorough understanding of neonatal physiology and pharmacology. Data from animals and human cohort studies have shown relation of the currently used anesthetics may associate with neurotoxic brain injury that lead to later neurodevelopmental impairment in the developing brain. In this review, the unique neonatal physiologic and pharmacologic features and anesthesia-related neurotoxicity will be discussed.

New technologies for essential newborn care in under-resourced areas: what is needed and how to deliver it

Globally, the largest contributors to neonatal mortality are preterm birth, intrapartum complications and infection. Many of these deaths could be prevented by providing temperature stability, respiratory support, hydration and nutrition; preventing and treating infections; and diagnosing and treating neonatal jaundice and hypoglycaemia. Most neonatal health-care technologies which help to accomplish these tasks are designed for high-income countries and are either unavailable or unsuitable in low-resource settings, preventing many neonates from receiving the gold standard of care. There is an urgent need for neonatal health-care technologies which are low-cost, robust, simple to use and maintain, affordable and able to operate from various power supplies. Several technologies have been designed to meet these requirements or are currently under development; however, unmet technology needs remain. The distribution of an integrated set of technologies, rather than separate components, is essential for effective implementation and a substantial impact on neonatal health. Close collaboration between stakeholders at all stages of the development process and an increased focus on implementation research are necessary for effective and sustainable implementation.

Influence of gestational age on dead space and alveolar ventilation in preterm infants ventilated with volume guarantee

BACKGROUND

Ventilated preterm infant lungs are vulnerable to overdistension and underinflation. The optimal ventilator-delivered tidal volume (VT) in these infants is unknown and may depend on the extent of alveolarisation at birth.

OBJECTIVES

We aimed to calculate respiratory dead space (VD) from the molar mass (MM) signal of an ultrasonic flowmeter (VD,MM) in very preterm infants on volume-targeted ventilation (VT target, 4-5 ml/kg) and to study the association between gestational age (GA) and VD,MM-to-VT ratio (VD,MM/VT), alveolar tidal volume (VA) and alveolar minute volume (AMV).

METHODS

This was a single-centre, prospective, observational, cohort study in a neonatal intensive care unit. Tidal breathing analysis was performed in ventilated very preterm infants (GA range 23-32 weeks) on day 1 of life.

RESULTS

Valid measurements were obtained in 43/51 (87%) infants. Tidal breathing variables were analysed using multivariable linear regression. VD,MM/VT was negatively associated with GA after adjusting for birth weight Z score (p < 0.001, R(2) = 0.26). This association was primarily influenced by the appliance dead space. Despite similar VT/kg and VA/kg across all studied infants, respiratory rate and AMV/kg increased with GA.

CONCLUSIONS

VD,app rather than anatomical VD is the major factor influencing increased VD,MM/VT at a younger GA. A volume guarantee setting of 4-5 ml/kg in the Dräger Babylog® 8000 plus ventilator may be inappropriate as a universal target across the GA range of 23-32 weeks. Differences between measured and set VT and the dependence of this difference on GA require further investigation.

A preterm pig model of lung immaturity and spontaneous infant respiratory distress syndrome

Respiratory distress syndrome (RDS) and bronchopulmonary dysplasia remain the leading causes of preterm infant morbidity, mortality, and lifelong disability. Research to improve outcomes requires translational large animal models for RDS. Preterm pigs delivered by caesarian section at gestation days (GD) 98, 100, 102, and 104 were provided 24 h of neonatal intensive care, monitoring (pulse oximetry, blood gases, serum biomarkers, radiography), and nutritional support, with or without intubation and mechanical ventilation (MV; pressure control ventilation with volume guarantee). Spontaneous development of RDS and mortality without MV are inversely related with GD at delivery and correspond with inadequacy of tidal volume and gas exchange. GD 98 and 100 pigs have consolidated lungs, immature alveolar architecture, and minimal surfactant protein-B expression, and MV is essential at GD 98. Although GD 102 pigs had some alveoli lined by pneumocytes and surfactant was released in response to MV, blood gases and radiography revealed limited recruitment 1-2 h after delivery, and mortality at 24 h was 66% (35/53) with supplemental oxygen provided by a mask and 69% (9/13) with bubble continuous positive airway pressure (8-9 cmH2O). The lungs at GD 104 had higher densities of thin-walled alveoli that secreted surfactant, and MV was not essential. Between GD 98 and 102, preterm pigs have ventilation inadequacies and risks of RDS that mimic those of preterm infants born during the saccular phase of lung development, are compatible with standards of neonatal intensive care, and are alternative to fetal nonhuman primates and lambs.