Surfactant-replacement therapy for respiratory distress in the preterm and term neonate

Surfactant administration and cerebral oxygenation and perfusion in preterm neonates - A systematic review of literature

BACKGROUND

Surfactant replacement is standard for preterm neonates with respiratory distress syndrome, improving survival and outcomes. Less invasive surfactant administration (LISA) and intubation-surfactant-extubation (INSURE) are preferred methods for surfactant replacement in spontaneously breathing preterm neonates. Despite the undeniable benefits of surfactant implementation in neonatal care, surfactant administration can affect vital parameters and cerebral oxygenation and perfusion, assessed by near-infrared spectroscopy (NIRS).

OBJECTIVE

This review systematically examined the literature on surfactant administration in preterm neonates and its impact on NIRS-measured cerebral oxygenation.

METHODS

A systematic search of PubMed, Embase, CINAHL, Clinical Trials, and Ovid Medline was conducted using following terms: newborn, infant, neonate, preterm, premature, prematurity, surfactant, LISA, less-invasive surfactant administration, INSURE, near-infrared-spectroscopy, NIRS, oximetry, spectroscopy, cerebral oxygenation, cerebral tissue oxygen saturation (crSO2), crSO2, cerebral perfusion. Only studies in human preterm neonates were included.

RESULTS

Sixteen studies were identified that described cerebral oxygenation measured by NIRS in the context of surfactant administration demonstrating a decrease in crSO2 during surfactant administration, followed by a subsequent increase. Three studies specifically described the course of crSO2 in neonates while receiving LISA, whereby in two of these LISA was compared to INSURE describing differences in crSO2 behaviour. Two additional studies described surfactant administration using the INSURE procedure and the influence on cerebral oxygenation. Ten studies investigated surfactant administration in intubated neonates receiving mechanical ventilation. One study described crSO2 in neonates receiving aerosolised surfactant.

CONCLUSION

This systematic review indicates that surfactant administration is associated with a transient decrease in crSO2 followed by a return to baseline levels, whereby differences between the LISA and INSURE methods were observed.

Comparison of Efficacy and Pharmacoeconomic Outcomes Between Calfactant and Poractant Alfa in Preterm Infants With Respiratory Distress Syndrome

OBJECTIVES

In order to evaluate the impact of the surfactant of choice selection, primary end points were to compare the average number of doses per patient, need for mechanical ventilation on day 3, hospital length of stay, and in-hospital mortality between calfactant and poractant alfa in preterm infants with respiratory distress syndrome (RDS). Secondary outcomes included administration complications, development of bronchopulmonary dysplasia (BPD), and estimated average per patient cost among the study population.

METHODS

A retrospective chart review was performed at a level IV neonatal intensive care unit between January 2020 and December 2021 to compare the efficacy, safety, and pharmacoeconomic outcomes -following a surfactant of choice switch from calfactant to poractant alfa in preterm infants with RDS.

RESULTS

Final analysis included 253 premature infants with gestational age (GA) between 22 and 36 weeks who met inclusion criteria. A total of 118 patients who received calfactant required higher average number of doses, 1.5 vs 1.3 doses (p = 0.031), and had more administration complications than 135 patients who received poractant alfa (10.2 vs 2.2%, p = 0.008). The need for redosing, mechanical ventilation on day 3, hospital length of stay, in-hospital mortality, and development of BPD were comparable between both groups. However, the estimated average per patient cost for poractant alfa was 32% higher than calfactant ($1,901 vs $1,439, p <0.001).

CONCLUSIONS

Despite the pharmacoeconomic disadvantage, preterm infants who received poractant alfa needed fewer doses and were less likely to have administration complications compared with those who received calfactant.

One-year survival and outcomes of infants born at 22 and 23 weeks of gestation in Sweden 2004-2007, 2014-2016 and 2017-2019

OBJECTIVE

To explore associations between perinatal activity and survival in infants born at 22 and 23 weeks of gestation in Sweden.

DESIGN/SETTING

Data on all births at 22 and 23 weeks' gestational age (GA) were prospectively collected in 2004-2007 (T1) or obtained from national registers in 2014-2016 (T2) and 2017-2019 (T3). Infants were assigned perinatal activity scores based on 3 key obstetric and 4 neonatal interventions.

MAIN OUTCOME

One-year survival and survival without major neonatal morbidities (MNM): intraventricular haemorrhage grade 3-4, cystic periventricular leucomalacia, surgical necrotising enterocolitis, retinopathy of prematurity stage 3-5 or severe bronchopulmonary dysplasia. The association of GA-specific perinatal activity score and 1-year survival was also determined.

RESULTS

977 infants (567 live births and 410 stillbirths) were included: 323 born in T1, 347 in T2 and 307 in T3. Among live-born infants, survival at 22 weeks was 5/49 (10%) in T1 and rose significantly to 29/74 (39%) in T2 and 31/80 (39%) in T3. Survival was not significantly different between epochs at 23 weeks (53%, 61% and 67%). Among survivors, the proportions without MNM in T1, T2 and T3 were 20%, 17% and 19% for 22 weeks and 17%, 25% and 25% for 23 weeks' infants (p>0.05 for all comparisons). Each 5-point increment in GA-specific perinatal activity score increased the odds for survival in first 12 hours of life (adjusted OR (aOR) 1.4; 95% CI 1.3 to 1.6) in addition to 1-year survival (aOR 1.2; 95% CI 1.1 to 1.3), and among live-born infants it was associated with increased survival without MNM (aOR 1.3; 95% CI 1.1 to 1.4).

CONCLUSION

Increased perinatal activity was associated with reduced mortality and increased chances of survival without MNM in infants born at 22 and 23 weeks of GA.

The history of neonatal intubation

Interest in 'resurrecting' the lifeless by supporting breathing has been described since ancient times. For centuries, methods of resuscitating animals, then humans and specifically the 'lifeless' neonate were debated and discussed. Over time, with experimentation and worldwide collaboration, endotracheal tubes and laryngoscopes specific to the newborn were created and their use refined. This historical work has meant that today, the neonatal community focuses on refining the science and the art of intubation for the benefit of the newborn; who, where, when and how to intubate, with what devices and medications, bringing about significant change in the area of neonatal intubation. Recent work has focused on alternatives to neonatal intubation as the risks of endotracheal intubation and mechanical ventilation have become clearer. Appreciating the history of neonatal intubation and its (somewhat cyclical) changes over time can show us how far we've come and how far we can still go in the resuscitation and respiratory support of newborns.

Health Economic Studies of Surfactant Replacement Therapy in Neonates with Respiratory Distress Syndrome: A Systematic Literature Review

BACKGROUND

Neonatal respiratory distress syndrome (RDS) is one of the most common problems for preterm infants, and symptoms include tachypnoea, grunting, retractions and cyanosis, which occur immediately after birth. Treatment with surfactants has reduced morbidity and mortality rates associated with neonatal RDS.

OBJECTIVE

The objective of this review is to describe the treatment costs, healthcare resource utilization (HCRU) and economic evaluations of surfactant use in the treatment of neonates with RDS.

METHODS

A systematic literature review (SLR) was performed to identify available economic evaluations and costs associated with neonatal RDS. Electronic searches were conducted in Embase, MEDLINE, MEDLINE In-Process, NHS EED, DARE and HTAD to identify studies published between 2011 and 2021. Supplementary searches of reference lists, conference proceedings, websites of global health technology assessment bodies and other relevant sources were conducted. Publications were screened by two independent reviewers for inclusion and followed the population, interventions, comparators and outcomes framework eligibility criteria. Quality assessment of the identified studies was performed.

RESULTS

Eight publications included in this SLR met all eligibility criteria: three conference abstracts and five peer-reviewed original research articles. Four of these publications evaluated costs/HCRU, and five (three abstracts and two peer-reviewed articles) investigated economic evaluations (two from Russia, and one each from Italy, Spain and England). The main cost drivers and causes of increased HCRU were invasive ventilation, duration of hospitalization and RDS-associated complications. There were no significant differences in neonatal intensive care unit (NICU) length of stay or NICU total costs between infants treated with beractant (Survanta^®), calfactant (Infasurf^®) or poractant alfa (Curosurf^®). However, treatment with poractant alfa was associated with reduced total costs compared with no treatment, continuous positive airway pressure (CPAP) alone or calsurf (Kelisu^®), due to shorter duration of hospitalization and fewer complications. Early use of the surfactant after birth was more clinically effective and cost-effective than late intervention in infants with RDS. Poractant alfa was found to be cost-effective and cost-saving compared to beractant for the treatment of neonatal RDS in two Russian studies.

CONCLUSION

There were no significant differences in NICU length of stay or NICU total costs between surfactants evaluated for treating neonates with RDS. However, early use of surfactant was found to be more clinically effective and cost-effective than late treatment. Treatment with poractant alfa was found to be cost-effective versus beractant and cost-saving compared with CPAP alone or beractant or CPAP in combination with calsurf. Limitations included the small number of studies, the geographic scope of the studies and the retrospective study design of the cost-effectiveness studies.

Can surfactants affect mortality and morbidity in term infants with respiratory failure?

BACKGROUND

We aimed to discuss term infants who are given surfactant due to respiratory disorder according to the underlying etiology, the dose of surfactant administration, and the need for repeated surfactant administration.

METHODS

In this retrospective study infants hospitalized in the 4th level neonatal intensive care unit during January 2019 and December 2021 and administered surfactant due to respiratory distress were included. Term infants given surfactant due to respiratory failure were included in the study through the data recording system. The number of surfactant doses, indications for administration, mortality, duration of hospitalization, intubation time, and inotrope use were recorded in the infants included in the study.

RESULTS

: During the two-year period, 1250 infants were hospitalized in our neonatal intensive care unit. Of those, 56 infants received surfactant replacement therapy for severe respiratory failure. There were 30 infants with pneumonia, 4 infants with meconium aspiration syndrome (MAS), and 22 infants with transient tachypnea of the newborn (TTN). It was seen that single-dose administration was higher in patients with TTN (p = 0.01), while multiple-dose surfactant administration was more common in patients with MAS, resulting in a statistical difference (p = 0.02). Mortality was lower, especially in cases given early surfactant administration and this situation was statistically significant (p < 0.001). Duration of intubation was 5.05 ± 4.7 days in early surfactant administration group and 8.0 ± 6.1 days in late surfactant administration group. This difference was statistically significant (p = 0.04). While early surfactant application was statistically higher in the TTN group (p = 0.007), late surfactant application was statistically higher in the pneumonia group (p = 0.001).

DISCUSSION

Despite the difference on administration time and repeat dose interval due to etiology, surfactant treatment is improving the respiratory distress of term infants.

New modes of surfactant delivery

The provision of exogenous surfactant to premature infants with respiratory distress syndrome has revolutionized the way we care for these patients, significantly improving survival and decreasing morbidity. Currently, the Intubate-SURfactant-Extubate (INSURE) to non-invasive ventilation method remains the standard method for surfactant delivery in the United States. However, the INSURE method requires intubation via direct visualization with a laryngoscope and possible need for sedation. Both carry significant risk to the patients, prompting the development of less invasive ways of safely and efficaciously providing surfactant to newborn infants. The present article reviews and describes the benefits and limitations of several of these alternative methods, including Less Invasive Surfactant Administration (LISA), Minimally Invasive Surfactant Therapy (MIST), via aerosolization, laryngeal mask airway (LMA), and direct nasopharyngeal deposition, focusing on assessment of clinical benefits and the level/risk of invasiveness.

Respiratory distress syndrome in preterm infants of less than 32 weeks: What difference does giving 100 or 200 mg/kg of exogenous surfactant make?

BACKGROUND

Surfactant dosing and effective delivery could affect continuous positive airways pressure (CPAP)-failure. Nevertheless, information on exogenous surfactant dosing with current administration methods is limited.

OBJECTIVE

To describe the effect of 100 or 200 mg/kg of surfactant as first-line treatment of respiratory distress syndrome in preterm infants of less than 32 weeks gestation.

STUDY DESIGN

A retrospective single-center cohort study comparing two epochs, before and after switching from 100 to 200 mg/kg surfactant therapy.

RESULTS

Six hundred and fifty-eight of the 1615 infants of less than 32 weeks were treated with surfactant: 282 received 100 mg/kg (S-100) and 376 received 200 mg/kg (S-200). There were no differences between S-100 and S-200 in perinatal data including prenatal corticosteroids, medication use, age at first surfactant administration and respiratory severity before surfactant. The S-200 vs. S-100 had fewer retreatments (17.0% vs. 47.2%, p < 0.001) and a shorter duration of oxygen therapy and mechanical ventilation (315 vs. 339 h, p = 0.018; 37 vs. 118 h, p = 0.000, respectively). There was no difference in postnatal corticosteroid use (S-200 10.0% vs. S-100 11.0%, p = 0.361). Bronchopulmonary dysplasia (BPD) was significantly lower in S-200 vs. S-100 when comparing either the 4 and 6-year periods before and after the dose switch (29.4% vs. 15.7%, p = 0.003, and 18.7% vs. 27.3%, p = 0.024, respectively) CONCLUSIONS: The switch from 100 to 200 mg/kg was associated with a marked reduction in the need for surfactant redosing, respiratory support, and BPD. This information could be important when designing a study in the modern era of less invasive administration as surfactant dosing and its effective delivery may affect the outcome.

Respiratory distress syndrome management in resource limited settings-Current evidence and opportunities in 2022

The complications of prematurity are the leading cause of neonatal mortality worldwide, with the highest burden in the low- and middle-income countries of South Asia and Sub-Saharan Africa. A major driver of this prematurity-related neonatal mortality is respiratory distress syndrome due to immature lungs and surfactant deficiency. The World Health Organization's Every Newborn Action Plan target is for 80% of districts to have resources available to care for small and sick newborns, including premature infants with respiratory distress syndrome. Evidence-based interventions for respiratory distress syndrome management exist for the peripartum, delivery and neonatal intensive care period- however, cost, resources, and infrastructure limit their availability in low- and middle-income countries. Existing research and implementation gaps include the safe use of antenatal corticosteroid in non-tertiary settings, establishing emergency transportation services from low to high level care facilities, optimized delivery room resuscitation, provision of affordable caffeine and surfactant as well as implementing non-traditional methods of surfactant administration. There is also a need to optimize affordable continuous positive airway pressure devices able to blend oxygen, provide humidity and deliver reliable pressure. If the high prematurity-related neonatal mortality experienced in low- and middle-income countries is to be mitigated, a concerted effort by researchers, implementers and policy developers is required to address these key modalities.

Perioperative Pulmonary Atelectasis: Part I. Biology and Mechanisms

Pulmonary atelectasis is common in the perioperative period. Physiologically, it is produced when collapsing forces derived from positive pleural pressure and surface tension overcome expanding forces from alveolar pressure and parenchymal tethering. Atelectasis impairs blood oxygenation and reduces lung compliance. It is increasingly recognized that it can also induce local tissue biologic responses, such as inflammation, local immune dysfunction, and damage of the alveolar-capillary barrier, with potential loss of lung fluid clearance, increased lung protein permeability, and susceptibility to infection, factors that can initiate or exaggerate lung injury. Mechanical ventilation of a heterogeneously aerated lung (e.g., in the presence of atelectatic lung tissue) involves biomechanical processes that may precipitate further lung damage: concentration of mechanical forces, propagation of gas-liquid interfaces, and remote overdistension. Knowledge of such pathophysiologic mechanisms of atelectasis and their consequences in the healthy and diseased lung should guide optimal clinical management.

Early nasal continuous positive airway pressure failure prediction in preterm infants less than 32 weeks gestational age suffering from respiratory distress syndrome

BACKGROUND

Early continuous positive airway pressure (CPAP) and surfactant replacement are effective treatments for neonatal respiratory distress syndrome (RDS). CPAP is the first line in preterm infants needing respiratory support, with surfactant replacement in case of CPAP failure (CPAP-F).

OBJECTIVES

To analyze incidence and factors associated with CPAP-F in preterm infants with RDS.

DESIGN, SETTING AND PATIENTS

Single-center retrospective database analysis (2004-2017) of inborn infants, gestational age (GA) 24 + 0/7-31 + 6/7 weeks, not intubated on admission to the neonatal intensive care unit, managed with CPAP. CPAP-F was defined as intubation and surfactant administration in the first 72 h of life; CPAP success (CPAP-S) was CPAP alone without need for additional RDS treatments. Demographic, respiratory, and clinical data associated with CPAP-F were studied using logistic regression analysis.

RESULTS

A total of 562 infants met the inclusion criteria: 252 (44.8%) were CPAP-F and 310 (55.2%) were CPAP-S. The CPAP-F, compared to CPAP-S group, had lower GA and birth weight, and were less likely to receive antenatal steroids or to be vaginal births. Logistic regression showed that the fraction of inspired oxygen (FiO₂ ) ≥ 0.23 between 180 and 240 min of life (FiO₂ 180-240 min) was the strongest factor associated with CPAP-F (odds ratio: 16.01 [95% confidence interval: 10.34-24.81]).

CONCLUSION

FiO₂ 180-240 min was highly predictive of CPAP-F in preterm infants. With this model for surfactant administration/CPAP-F, 11.2% of infants would have unnecessarily received treatment, but importantly, 27.7% would have been treated much earlier, with a potential reduction in air leaks and duration of mechanical ventilation.

Decreased ventricular size and mass mediate the reduced exercise capacity in adolescents and adults born premature

BACKGROUND

Premature birth is associated with lower levels of cardiorespiratory fitness (CRF) but the underlying mechanisms responsible remain unclear. This study assessed whether differences in cardiac morphology or function mediate differences in CRF among adolescents and young adults born preterm.

METHODS

Adolescents and young adults born moderately to extremely premature (gestational age ≤ 32 weeks or birth weight < 1500 g) and age-matched term born participants underwent resting cardiac MRI and maximal exercise testing. Mediation analysis assessed whether individual cardiovascular variables accounted for a significant proportion of the difference in maximal aerobic capacity between groups.

RESULTS

Individuals born preterm had lower VO2max than those born term (41.7 ± 8.6 v 47.5 ± 8.7, p < 0.01). Several variables differed between term and preterm born subjects, including systolic and diastolic blood pressure, mean pulmonary artery pressure, indexed left ventricular end-diastolic volume (LVEDVi), right ventricular end-diastolic volume (RVEDVi), LV mass (LVMi), LV stroke volume index (LVSVi), and LV strain (p < 0.05 for all). Of these variables, LVEDVi, RVEDVi, LVSVi, LVMi, and LV longitudinal strain were significantly related to VO2max (p < 0.05 for all). Significant portions of the difference in VO2max between term and preterm born subjects were mediated by LVEDVi (74.3%, p = 0.010), RVEDVi (50.6%, p = 0.016), and LVMi (43.0%, p = 0.036).

CONCLUSIONS

Lower levels of CRF in adolescents and young adults born preterm are mediated by differences in LVEDVi, RVEDVi, and LVMi. This may represent greater risk for long-term cardiac morbidity and mortality in preterm born individuals.

A Randomized Clinical Trial of Intratracheal Administration of Surfactant and Budesonide Combination in Comparison to Surfactant for Prevention of Bronchopulmonary Dysplasia

Objectives

Bronchopulmonary dysplasia (BPD) remains a major problem in preterm infants occurring in up to 50% of infants born at < 28 weeks gestational age. Inflammation plays an important role in the pathogenesis of BPD. This study was conducted to evaluate the efficacy of intratracheal budesonide administration in combination with a surfactant in preventing BPD in preterm infants.

Methods

In a randomized clinical trial, 128 preterm infants at < 30 weeks gestational age and weighing < 1500 g at birth were studied. All had respiratory distress syndrome (RDS) and needed surfactant replacement therapy. They were randomly allocated into two groups; surfactant group (n = 64) and surfactant + budesonide group 
(n = 64). Neonates in the surfactant group received intratracheal Curosurf 200 mg/kg/dose. Patients in the surfactant + budesonide group were treated with intratracheal instillation of a mixed suspension of budesonide 0.25 mg/kg and Curosurf 200 mg/kg/dose. Neonates were followed untill discharge for the primary outcome which was BPD and secondary outcomes including sepsis, patent ductus arteriosus (PDA), retinopathy of prematurity (ROP), and necrotizing enterocolitis (NEC).

Results

The mean gestational age and birth weight of the studied neonates were 28.3±1.6 weeks and 1072.0±180.0 g, respectively. The demographic characteristics and RDS score were similar in the two groups. BPD occurred in 24 (37.5%) neonates in the surfactant + budesonide group and 38 (59.4%) neonates in surfactant group, p = 0.040. Hospital stay was 29.7±19.2 days (median = 30 days) in the surfactant group and 23.3±18.1 days (median = 20 days) in the surfactant + budesonide group, p = 0.050. The rates of sepsis, PDA, ROP, and NEC were not significantly different in the two groups.

Conclusions

The use of budesonide in addition to surfactant for rescue therapy of RDS in preterm infants decreases the incidence of BPD and duration of respiratory support significantly. Large adequately powered clinical trials with long-term safety assessments are needed to confirm our findings before its routine use can be recommended.

Current respiratory support practices in premature infants: an observational study

This study aims to describe longitudinally the current invasive and non-invasive ventilation practices in premature infants in a single neonatal intensive care unit (NICU). It´s a retrospective chart review including 682 babies born at gestational age ≤35 weeks, admitted to the NICU at Erasme Hospital, between 1^st of January 2001 and 31^st of December 2011, the different ventilatory support used were analyzed. This population was stratified depending on gestational age and the recruitment period on 3 groups. All infants born <28 weeks of GA (group 1) needed some kind of respiratory support of which 22% non-invasive. Among babies born after 28 to 31 weeks (group 2), 10.2% didn´t need any ventilatory support and 42% needed a non-invasive respiratory support. In neonates from 32 to 35 weeks of GA (group 3) respiratory support was needed in 34.9%, 65% of which was non-invasive. The median duration of endotracheal ventilation was: 6, 1 and 2 days, and of non-invasive support: 41, 17 and 2 days in group 1, 2 and 3 respectively. One single premature baby could pass along the first weeks through all modes. In premature infants whose respiratory support was needed, the median age at the end of support was remarkably constant at 33 - 34 weeks of corrected age. We conclude that is an important diversity and a significant complementarity between modes of respiratory support for premature infants. Invasive ventilation decreased significantly for group 2, but is still remarkably long for group 1.

The efficacy of intratracheal administration of surfactant and budesonide combination in the prevention of bronchopulmonary dysplasia

Background:

Bronchopulmonary dysplasia (BPD) remains a major problem in preterm infants that occurs in up to 50% of preterm infants. The inflammation plays an important role in its pathogenesis. This study was conducted to evaluate the efficacy intratracheal budesonide administration in combination with surfactant in the prevention of BPD in preterm infants.

Materials and Methods:

In a randomized controlled clinical trial, 128 preterm infants with gestation age <30 weeks and birth weight <1250 g who had respiratory distress syndrome (RDS) and need surfactant replacement therapy were studied. They randomly allocated into two groups, surfactant group (n = 64) and surfactant + budesonide group (n = 64). Patients were followed till discharge for the primary outcome which was BPD.

Results:

The mean gestation age and birth weight of studied neonates were 28.3 ± 1.6 weeks and 1072 ± 180 g, respectively. BPD was occurred in 20 (31.3%) neonates in surfactant + budesonide group and 38 (59.4%) patients in surfactant group, P = 0.02. Respiratory support was needed in two groups similarly, but the mean duration of respiratory support was significantly longer in surfactant group in comparison with surfactant + budesonide group (mechanical ventilation 2.8 ± 0.6 vs. 0.8 ± 0.1 days, P = 0.006, nasal continuous positive airway pressure 5.2 ± 3.0 vs. 4.0 ± 3.5 days, P = 0.04 and high flow nasal cannula 7.7 ± 0.9 vs. 4.1 ± 0.5 days, P = 0.001).

Conclusion:

Based on our findings, the use of budesonide in addition to surfactant for rescue therapy of RDS significantly decreases the incidence of BPD and duration of respiratory support. Future studies are recommended with a large number of patients before routine administration of surfactant and budesonide combination.

Towards homogenization of liquid plug distribution in reconstructed 3D upper airways of the preterm infant

Liquid plug therapies are commonly instilled in premature babies suffering from infant respiratory distress syndrome (IRDS) by a procedure called surfactant replacement therapy (SRT) in which a surfactant-laden bolus is instilled endotracheally in the neonatal lungs, dramatically reducing mortality and morbidity in neonatal populations. Since data are frequently limited, the optimal method for surfactant delivery has yet to be established towards more standardized guidelines. Here, we explore the dynamics of liquid plug transport using an anatomically-relevant, true-scale in vitro 3D model of the upper airways of a premature infant. We quantify the initial plug's distribution as a function of two underlying parameters that can be clinically controlled; namely, the injection flow rate and the viscosity of the administered fluid. By extracting a homogeneity index (HI), our in vitro results underline how the combination of both high fluid viscosity and injection flow rates may be advantageous in improving homogeneous dispersion. Such outcomes are anticipated to help refine future SRT administration guidelines towards more uniform distribution using more anatomically-realistic 3D in vitro models at true scale of the preterm neonate.

Performance of Low Air Volume Dry Powder Inhalers (LV-DPI) when Aerosolizing Excipient Enhanced Growth (EEG) Surfactant Powder Formulations

Efficient delivery of dry powder aerosols dispersed with low volumes of air is challenging. This study aims to develop an efficient dry powder inhaler (DPI) capable of delivering spray-dried Survanta-EEG powders (3-10 mg) with a low volume (3 mL) of dispersion air. A series of iterative design modifications were made to a base low air volume actuated DPI. The modifications included the replacement of the original capsule chamber with an integral dose containment chamber, alteration of the entrainment air flow path through the device (from single-sided (SS) to straight through (ST)), change in the number of air inlet holes (from one to three), varying the outlet delivery tube length (45, 55, and 90 mm) and internal diameter (0.60, 0.89, and 1.17 mm). The modified devices were evaluated by determining the influence of the modifications and powder fill mass on aerosol performance of spray-dried Survanta-EEG powders. The optimal DPI was also evaluated for its ability to aerosolize a micronized powder. The optimized dose containment unit DPI had a 0.21 mL powder chamber, ST airflow path, three-0.60 mm air inlet holes, and 90 mm outlet delivery tube with 0.89 mm internal diameter. The powder dispersion characteristics of the optimal device were independent of fill mass with good powder emptying in one 3 mL actuation. At 10 mg fill mass, this device had an emitted mass of 5.3 mg with an aerosol Dv50 of 2.7 μm. After three 3 mL actuations, >85% of the spray-dried powder was emitted from the device. The emitted mass of the optimal device with micronized albuterol sulfate was >72% of the nominal fill mass of 10 mg in one 3 mL actuation. Design optimization produced a DPI capable of efficient performance with a dispersion air volume of 3 mL to aerosolize Survanta-EEG powders.

BPD treatments: The never-ending smorgasbord

Despite important advances in neonatal care, rates of bronchopulmonary dysplasia (BPD) have remained persistently high. Numerous drugs and ventilator strategies are used for the prevention and treatment of BPD. Some, such as exogenous surfactant, volume targeted ventilation, caffeine, and non-invasive respiratory support, are associated with modest but important reductions in rates of BPD and long-term respiratory morbidities. Many other therapies, such as corticosteroids, diuretics, nitric oxide, bronchodilators and anti-reflux medications, are widely used despite conflicting, limited or no evidence of efficacy and safety. This paper examines the range of therapies used for the prevention or treatment of BPD. They are classified into those supported by evidence of effectiveness, and those which are widely used despite limited evidence or unclear risk to benefit ratios. Finally, the paper explores emerging therapies and approaches which aim to prevent or reduce BPD and long-term respiratory morbidity.

Decreasing cerebral palsy prevalence in multiple births in the modern era: a population cohort study of European data

Multiple births (twins or higher order multiples) are increasing in developed countries and may present higher risk for cerebral palsy (CP). However, few studies can reliably investigate trends over time because these outcomes are relatively rare.

OBJECTIVE

We pooled data from European CP registers to investigate CP birth prevalence and its trends among single and multiple births born between 1990 and 2008.

DESIGN

Population cohort study.

SETTING

12 population-based registers from the Surveillance of Cerebral Palsy in Europe collaboration.

PARTICIPANTS

4 446 125 single and multiple live births, of whom 8416 (0.19%) had CP of prenatal or perinatal origin.

MAIN OUTCOMES

CP diagnosis ascertained in childhood using harmonised methods; CP subtype; Motor impairment severity among CP cases.

RESULTS

The rate of multiple births increased from 1990. Multiples displayed higher risk for CP (RR=4.27, 95% CI 4.00 to 4.57). For singletons and multiples alike, risk for CP was higher among births of lower gestational age (GA) or birth weight (BW). However, CP birth prevalence declined significantly among very preterm (<32 weeks) and very low BW (<1500 g) multiples. Singletons and multiples with CP displayed similar severity of motor impairment.

CONCLUSIONS

Between 1990 and 2008, CP birth prevalence decreased steadily among multiples with low GA or BW. Furthermore, multiples with CP display similar profiles of severe motor impairment compared with CP singletons. Improvements in management of preterm birth since the 1990s may also have been responsible for providing better prospects for multiples.

Pulmonary Surfactant Replacement Therapy for Respiratory Distress Syndrome in Neonates: a Nationwide Epidemiological Study in Korea

BACKGROUND

Pulmonary surfactant (PS) replacement therapy, as a safe and effective treatment for respiratory distress syndrome (RDS) may have further increased with the extended insurance coverage since 2011 in Korea. Thus, this study aimed to investigate the epidemiologic data of PS replacement therapy for RDS in Korea and to analyze the complications associated with RDS.

METHODS

We included 19,442 infants who were treated with PS and diagnosed with RDS (International Classification of Diseases-10 codes: P22.0) between 2014 and 2018 from the Health Insurance Review and Assessment database. Birth certificate data from Statistics Korea were used to estimate the incidence of RDS.

RESULTS

The average incidence of RDS within the study period was 0.99% among live births. Repeated doses of PS were administered to 1,688 infants (8.7%), ranging from 2 doses in 929 infants (4.8%) to 9 doses in 1 infant (0.01%). The incidence of RDS in term infants markedly increased over 5 years from 0.2% to 0.34%. The incidence was similarly increased among the preterm infants. The RDS mortality rate was 6.3% and showed a decreasing trend according to year. The mortality rate was significantly higher in the lower gestational age group. A decreasing trend was observed in the incidence of the complications, such as patent ductus arteriosus, intraventricular hemorrhage, and bronchopulmonary dysplasia, except for pneumothorax in term infants. The complications were also higher in the lower gestational age group and the lower birth weight group. However, pneumothorax was the most frequent complication in the term infant group and in infants with birth weight ≥ 2,500 g.

CONCLUSION

Advancements in neonatal care and extended insurance coverage have increased the use of PS replacement therapy for RDS. This, in turn, decreased neonatal mortality and the incidence of the associated complications. The appropriate therapeutic strategy for RDS should be decided according to the gestational age and lung pathology.

Extrapulmonary Surfactant Therapy: Review of Available Data and Research/Development Issues

Since the discovery of surfactant, a large amount of knowledge has been accumulated about its biology and pharmacology. Surfactant is the cornerstone of neonatal respiratory critical care, but its proteins and phospholipids are produced in various tissues and organs, with possible roles only partially similar to that played in the alveoli. As surfactant research is focused mainly on its respiratory applications, knowledge about the possible role of surfactant in extrapulmonary disorders has never been summarized. Here we aim to comprehensively review the data about surfactant biology and pharmacology in organs other than the lung, especially focusing in the more promising surfactant extrapulmonary roles. We also review any preclinical or clinical data available about the therapeutic use of surfactant in these contexts. We offer a summary of knowledge and research/development milestones, as possible useful guidance for researchers of multidisciplinary background.

Outcome of late preterm newborns in Upper Egypt

Background

The incidence of preterm births is increasing and has become a global health concern. This study aimed to compare the outcome of late preterm (LPT) to full term (FT) neonates at two large hospitals in Upper Egypt.

Results

Out of 250 newborns included in the study, 180 (72%) were FT and 70 (28%) were LPT. More than half of the LPT newborns (52.9%) were admitted to the neonatal intensive care unit (NICU), compared with 26.7% of FT newborns. Delivery of LPT was associated with an increased risk of neonatal morbidity, including jaundice requiring phototherapy (34.3% vs. 7.8%), respiratory morbidities (32.9% vs. 13.9%), hypoglycemia (8.6% vs. 1.7 %), and convulsions (4.3% vs. 0.6%).

Conclusions

LPT neonates were more susceptible to suffer from jaundice and respiratory distress among other morbidities. They also had a higher rate of NICU admission, longer duration of NICU stay, as well as a higher mortality rate. The best treatment of late prematurity is to prevent it. Public and professional awareness of the problems associated with late prematurity should be highlighted. Follow-up programs for early detection and intervention for long term complications are recommended.

Minimally invasive surfactant therapy versus intubation for surfactant administration in very low birth weight infants with respiratory distress syndrome

BACKGROUND

Minimally invasive surfactant therapy (MIST) is a new mode of surfactant administration without intubation to spontaneously breathing preterm infants with respiratory distress syndrome (RDS). The aims of this study were to assess the feasibility, efficacy and safety of using MIST to give surfactant for very low birth weight (VLBW) infants with RDS.

METHODS

In total, 53 VLBW infants who were born before 32 gestational weeks with spontaneous breathing, respiratory distress, and requiring surfactant therapy were divided into two groups. The infants in group A (n = 29) were intubated and received surfactant replacement therapy via endotracheal tube, followed by mechanical ventilation (MV). The infants in group B (n = 24) received tracheal instillation of surfactant via a semirigid vascular catheter during spontaneous breathing under nasal continuous positive airway pressure (nCPAP). After surfactant instillation, the infants in group B were still placed on nCPAP.

RESULTS

Our data showed that infants in group B (MIST group) had significantly lower rate (P < 0.05) of composite outcome of death or bronchopulmonary dysplasia (BPD), duration of intermittent positive airway pressure ventilation (IPPV) or MV, drug treatment of patent ductus arteriosus (PDA), and surgical ligation of PDA than group A.

CONCLUSION

MIST is feasible, safe and it may reduce the composite outcome of death or BPD for VLBW infants with RDS requiring surfactant replacement therapy.

Revisiting OPLS-AA Force Field for the Simulation of Anionic Surfactants in Concentrated Electrolyte Solutions

Hereby, we developed a set of nonbonded parameters within all-atom optimized potentials for liquid simulations (OPLS-AA) force field for the simulation of concentrated electrolyte solutions of anionic surfactants. More specifically, the aim of this paper is to assess the performance of five sets of atomic charges calculated using different population analyses (DDEC6, CHelpG, CHelpG-SMD, RESP, and CM5), as well as the original set of charges used in the literature for sodium dodecyl sulfate (SDS) simulation. Recently, Farafonov et al. have revised the SDS OPLS-AA force field; however, we were unable to obtain the experimental rodlike micelles using this parameter set on long time scale. In fact, the initial SDS bilayer micelle adopted a rodlike shape transiently and then broke down into spherical micelles. Updating OPLS-AA force field with DDEC6, CHelpG, and CHelpG-SMD charges resulted in stable rod micelles for a long simulation time (1 μs). The atomic charges of Farafonov (taken from Shelley et al.), RESP, and CM5 could not correctly describe SDS in concentrated electrolyte solutions. Analysis of the interaction of SDS with the counterions and solvent highlights the role of a balance of the intermolecular forces that must be met to describe adequately the anionic surfactant electrolyte solutions. Further, the optimization of the SDS Lennard-Jones parameters enabled the Farafonov set to properly reproduce the experimental rod micelle. In addition, we have examined the performance of different parameters of sodium ions: the first developed based on the Kirkwood-Buff integrals (KBI) and the second developed by Joung et al. The excessive ion pairing caused by KBI parameters screens significantly SDS-water interactions, which stabilize the rod micelle. Further, a tight interaction of the Na⁺-SDS head group resulted in stabilization of the bilayer micelle as observed in the case of Na⁺ parameters developed by Joung et al.

Porcine versus bovine surfactant therapy for RDS in preterm neonates: pragmatic meta-analysis and review of physiopathological plausibility of the effects on extra-pulmonary outcomes

BACKGROUND

While porcine seems to be superior to bovine surfactants in terms of respiratory outcomes, it is unclear if a surfactant can improve extra-pulmonary outcomes in preterm neonates with respiratory distress syndrome and if there is any physiopathological/biological mechanism linking surfactant therapy to these outcomes. We aim to fill these knowledge gaps.

METHODS

Systematic and pragmatic review coupled with meta-analysis of randomized controlled trials of bovine or porcine surfactants administered to treat RDS in preterm neonates; common extra-pulmonary neonatal intensive care outcomes were considered. As additional analysis, animal or human translational studies about mechanisms linking surfactant replacement to extra-pulmonary neonatal outcomes were also systematically reviewed.

RESULTS

Porcine surfactant is associated with lower incidence of patent ductus arteriosus (OR:0.655; 95%CI:0.460-0.931); p = 0.018; 12 trials; 1472 patients); prenatal steroids (coeff.:-0.009, 95%CI:-0.03-0.009, p = 0.323) and gestational age (coeff.:0.079, 95%CI:-0.18-0.34, p = 0.554) did not influence this effect size. No significant differences were found between porcine and bovine surfactants on neonatal intensive care unit length of stay (mean difference (days):-2.977; 95%CI:-6.659-0.705; p = 0.113; 8 trials; 855 patients), intra-ventricular hemorrhage of any grade (OR:0.860; 95%CI:0.648-1.139); p = 0.293; 15 trials; 1703 patients), severe intra-ventricular hemorrhage (OR:0.852; 95%CI:0.624-1.163); p = 0.313; 15 trials; 1672 patients), necrotizing entero-colitis (OR:1.190; 95%CI:0.785-1.803); p = 0.412; 9 trials; 1097 patients) and retinopathy of prematurity (OR:0.801; 95%CI:0.480-1.337); p = 0.396; 10 trials; 962 patients).

CONCLUSIONS

Physiopathological mechanisms explaining the effect of surfactant have been found for patent ductus arteriosus only, while they are lacking for all other endpoints. Porcine surfactant is associated with lower incidence of PDA than bovine surfactants. As there are no differences in terms of other extra-pulmonary outcomes and no physiopathological plausibility, these endpoints should not be used in future trials.

REGISTRATION

PROSPERO n.CRD42018100906.

Minimally Invasive Surfactant Administration for the Treatment of Neonatal Respiratory Distress Syndrome: A Multicenter Randomized Study in China

Background/Aims: Nasal continuous positive airway pressure (nCPAP) was recommended as the initial respiratory support for spontaneous breathing in infants with very low birth weight and neonatal respiratory distress syndrome (NRDS). Less invasive surfactant administration (LISA) and minimally invasive surfactant therapy (MIST) have been reported to reduce the incidence of bronchopulmonary dysplasia (BPD). This study aimed to explore the applicability of minimally invasive surfactant administration (MISA) in China. Materials and Methods: MISA was a randomized controlled study conducted at eight level III neonatal intensive care units (NICUs) in China. Spontaneously breathing infants born at 25+0 to 31+6 weeks' gestation who progressively developed respiratory distress during the first 6 h after birth were randomly assigned to receive MISA or endotracheal intubation surfactant administration (EISA). The primary outcome was the difference in the morbidity of BPD between two groups of infants with MISA and EISA at 36 weeks corrected gestational age. Results: Demographic and clinical characteristics of the 151 infants in the MISA group were similar to the 147 infants in the EISA group. The comparison showed no clear benefits in the MISA group in the incidence of BPD, while infants from the EISA group had higher rates of patent ductus arteriosus (PDA) (60.5 vs. 41.1%, p = 0.001). The duration of surfactant infusion and the total time of surfactant administration in the MISA group were significantly longer than in the EISA group. A slightly increased heart rate was noted 1 h post surfactant administration in the EISA group. In subgroup analysis, the comparison of 51 smaller (<30 weeks) preterm infants, named MISAs (n = 31) and EISAs (n = 20), showed a significant reduction of BPD (29.0 vs. 70.0%, p = 0.004) and PDA (29.0 vs. 65.0%, p = 0.011). In the subgroup analysis of blood gas, arterial oxygen saturation (SaO₂) value at 1 and 12 h and partial pressure of arterial oxygen (PaO₂) at 12 h were all higher in the EISA group compared to the MISA group. Conclusion: MISA had no clear benefit on the incidence of BPD, but it was related to a reduction in PDA. It is an appropriate therapy for spontaneous breathing in infants with extremely low birth weight and NRDS.

Visual function scale for identification of infants with low respiratory compliance

AIM

Precise estimation of respiratory function is essential to optimise neonatal respiratory care. However, current clinical scores have not been validated with quantitative measures of respiratory function. The aim of this study was to develop a physiological scoring system to predict low respiratory dynamic compliance of <0.6 ml/cmH₂O/kg.

METHODS

Forty-four newborn infants were studied before (dynamic compliance) and shortly after scheduled extubation (physiological signs). A novel scoring system was developed based on the association between physiological signs and dynamic compliance.

RESULTS

The respiratory rate was identified as the primary independent variable for dynamic compliance in the univariate analysis. The prediction score for low dynamic compliance comprised the presence of nasal flaring, see-saw respiration, suprasternal/intercostal retraction, and the respiratory rate ranks (0-3). The area under the receiver-operating characteristics curve of the composite score had discriminatory capability of 0.86 (95% confidence interval: 0.75-0.97) to predict low dynamic compliance with the optimal cut-off value of ≥3 (sensitivity, 0.882; specificity, 0.667).

CONCLUSION

Our novel scoring system might help predict newborn infants with low dynamic compliance, who may require escalation of respiratory support, or transfer to higher level units.

Mechanistic profiling of the release kinetics of siRNA from lipidoid-polymer hybrid nanoparticles in vitro and in vivo after pulmonary administration

Understanding the release kinetics of siRNA from nanocarriers, their cellular uptake, their in vivo biodistribution and pharmacokinetics is a fundamental prerequisite for efficient optimisation of the design of nanocarriers for siRNA-based therapeutics. Thus, we investigated the influence of composition on the siRNA release from lipid-polymer hybrid nanoparticles (LPNs) consisting of cationic lipidoid 5 (L₅) and poly(DL-lactic-co-glycolic acid) (PLGA) intended for pulmonary administration. An array of siRNA-loaded LPNs was prepared by systematic variation of: (i) the L₅ content (10-20%, w/w), and (ii) the L₅:siRNA ratio (10,1-30:1, w/w). For comparative purposes, L₅-based lipoplexes, L₅-based stable nucleic acid lipid nanoparticles (SNALPs). and dioleoyltrimethylammoniumpropane (DOTAP)-modified LPNs loaded with siRNA were also prepared. Release studies in buffer and lung surfactant-containing medium showed that siRNA release is dependent on the presence of both surfactant and heparin (a displacing agent) in the release medium, since these interact with the lipid shell structure thereby facilitating decomplexation of L₅ and siRNA, as evident from the retarded siRNA release when the L₅ content and the L₅:siRNA ratio were increased. This confirms the hypothesis that siRNA loaded in LPNs is predominantly present as complexes with the cationic lipid and primarily is located near the particle surface. Cellular uptake and tolerability studies in the human macrophage cell line THP-1 and the type I-like human alveolar epithelial cell line hAELVi, which together represents a monolayer-based barrier model of lung epithelium, indicated that uptake of LPNs was much higher in THP-1 cells in agreement with their primary clearance role. In vivo biodistributions of formulations loaded with Alexa Fluor® 750-labelled siRNA after pulmonary administration in mice were compared by using quantitative fluorescence imaging tomography. The L₅-modified LPNs, SNALPs and DOTAP-modified LPNs displayed significantly increased lung retention of siRNA as compared to L₅-based lipoplexes, which had a biodistribution profile comparable to that of non-loaded siRNA, for which >50% of the siRNA dose permeated the air-blood barrier within 6 h and subsequently was excreted via the kidneys. Hence, the enhanced lung retention upon pulmonary administration of siRNA-loaded LPNs represents a promising characteristic that can be used to control the delivery of the siRNA cargo to lung tissue for local management of disease.

Aerosolized surfactant in neonatal respiratory distress syndrome: Phase I study

BACKGROUND

Treating respiratory distress syndrome (RDS) with intratracheal surfactant requires endotracheal intubation and mechanical ventilation, (MV) with their attendant risks. Use of non-invasive respiratory support in the delivery room averts the need for MV but delays surfactant administration.

OBJECTIVE

We hypothesized that aerosolized surfactant is feasible and safe in infants 24^0/7-36^6/7 weeks gestational age (GA) with RDS, receiving non-invasive respiratory support.

DESIGN/METHODS

In an unblinded Phase I study, sequentially enrolled infants with RDS stratified by GA received increasing doses (100 or 200 mg/kg of phospholipid) and dilutions (12.5 or 8.3 mg/ml) of surfactant using a jet nebulizer. Infants were monitored clinically and with cerebral oximetry.

RESULTS

Seventeen infants were enrolled. Age at start of first dose and dose duration were 4.9 (3.4-10.1) and 2.1 (1.0-2.8) hours respectively. Two infants in the lowest GA stratum (24^0/7-28^6/7) required intubation within 2 h after the first dose. Fifteen infants completed the study; 13 received two doses. Infants tolerated the aerosol treatment well. No other significant adverse events were identified. Parental permission for cerebral oximetry was obtained in 16 infants. In the two infants who later exited the study, values prior to start of aerosolized surfactant were lower compared to 14 infants who completed the study (p = 0.0835), increased after start of study intervention (p = 0.0105) and decreased after intubation (p = 0.0003).

CONCLUSIONS

We have demonstrated the feasibility and safety of aerosolized surfactant in preterm infants receiving non-invasive respiratory support. The treatment was well tolerated by infants and clinical caregivers.

Health Economics and Outcomes of Surfactant Treatments for Respiratory Distress Syndrome Among Preterm Infants in US Level III/IV Neonatal Intensive Care Units

OBJECTIVE

To compare length of stay (LOS), costs, mechanical ventilation (MV), and mortality in preterm infants treated in the Neonatal Intensive Care Unit (NICU) with beractant (BE), calfactant (CA), and poractant alfa (PA) for Respiratory Distress Syndrome (RDS).

METHODS

This study evaluated preterm infants born between 2010 and 2013 with RDS diagnosis, gestational age of 25 to 36 weeks, birthweight of ≥500 g, and age of ≤2 days on first surfactant administration. Multivariable regression was used to evaluate all NICU outcomes.

RESULTS

Of 13,240 infants meeting the study criteria, 4136 (31.2%) received BE, 2502 (18.9%) received CA, and 6602 (49.9%) received PA. Adjusted analyses estimated similar mean LOS (BE 26.7 days, CA 27.8 days, and PA 26.2 days) and hospital costs (BE: $50,929; CA: $50,785; and PA: $50,212). Compared to PA, BE and CA were associated with greater odds of MV use on day 3 (OR = 1.56 and 1.60, respectively) and day 7 (OR = 1.39 and 1.28, respectively; all p < 0.05). Adjusted NICU mortality was significantly higher only with CA vs PA (OR = 1.51; p = 0.015).

CONCLUSION

Adjusted NICU LOS and costs were similar among BE, CA, and PA. Infants receiving PA were less likely to be on MV at 3 and 7 days, and PA treatment was associated with lower odds of NICU mortality when compared to CA.

Pulmonary hemorrhage in neonatal respiratory distress syndrome: Radiographic evolution, course, complications and long-term clinical outcomes

BACKGROUND

Pulmonary hemorrhage (PH) is occasionally seen in premature infants after surfactant treatment for respiratory distress syndrome (RDS). These infants receive frequent chest radiographs (CXR) during and after hospitalization enabling long-term radiographic-clinical correlation.

OBJECTIVE

To chart the natural evolution of CXR findings of PH in RDS and correlate radiographic patterns to supplemental oxygen requirement.

MATERIALS AND METHODS

Retrospective review of clinical notes for gestational age (GA), birth weight (BW), intraventricular hemorrhage (IVH) and oxygen requirement were performed. CXRs were reviewed at 4 time-points; during PH, 28 days postnatal age, 36 weeks and at farthest available clinical follow-up.

RESULTS

18 infants born (2003-2016), GA (24-30 weeks); BW (482-1590 grams) were included. Mean onset of PH was 1.94 (0-5) days. 9/18 (50%) had IVH. 3 died during PH; all had IVH. During PH, CXR showed whiteout 9/18 (50%); patchy opacities 5/18 (27%); diffuse haziness 1/18 (6%) and no change 3/18 (17%). At 28 days postnatal age, CXR showed fine-interstitial (FI) markings 14/15 (93%) and whiteout 1/15 (7%). At 36 weeks,12/14 (85%) had FI and 2/14 (15%) developed cystic-interstitial changes. At farthest follow-up, FI 3/13 (23%); coarse-interstitial 4/13 (30%); peri-bronchial cuffing 5/13 (38%); normal 1/13 (9%) and the majority had hyperinflation 9/13 (69%). At discharge, 9/14 (64%) required home-oxygen and 5/14 (36%) were on room-air. At farthest follow-up, 6/14 (42%) required home-oxygen and 8/14 (58%) were on room-air.

CONCLUSION

Premature infants that survive PH may later develop chronic lung disease of prematurity with an evolving interstitial pattern on CXR that clears overtime as they outgrow the need for supplemental oxygen.

Public Health Implications of Very Preterm Birth

With advanced perinatal care and technology, survival among infants born very preterm (<32 weeks gestation) has improved dramatically over the last several decades. However, adverse medical and neurodevelopmental outcomes for those born very preterm remains high, particularly at the lowest gestational ages. Public health plays a critical role in providing data to assess population-based risks associated with very preterm birth, addressing disparities, and identifying opportunities for prevention, including improving the health of reproductive-age women, before, during, and after pregnancy.

Management of respiratory complications in a western lowland gorilla (Gorilla gorilla gorilla) born by cesarean section

A female western lowland gorilla (Gorilla gorilla gorilla) infant was delivered by cesarean section (C-section) to an 18-year-old primiparous dam after prolonged labor. The infant required resuscitation at birth and was hospitalized for management of pneumonia and associated respiratory distress secondary to the aspiration of meconium-stained amniotic fluid. The infant received nine days of intensive care with respiratory support, antibiotics, intravenous fluid therapy, anti-inflammatory drugs, bronchodilators, and chest physiotherapy. Respiratory support included nasal continuous positive airway pressure (CPAP), and supplemental oxygen. Complications included right lung atelectasis secondary to bronchial obstruction and pneumonia. Following the resolution of pneumonia, visual reintroductions with the troop were initiated. The dam was given a medical lactation supplement (metoclopramide) and her mammary glands were stimulated to increase milk production. After several days of visual and olfactory introductions, the infant was successfully physically reintroduced to her dam at 12 days of age; the dam showed appropriate maternal response and nursing of the infant. The infant had appropriate growth and development, and 4 years later, has no evidence of negative side effects of neonatal respiratory disease. This is the first reported case of management of neonatal gorilla respiratory disease associated with a C-section, with successful reintroduction to the family group after hospitalization.

Early elective delivery for fetal ventriculomegaly: are neurosurgical and medical complications mitigated by this practice?

PURPOSE

Antenatally diagnosed ventriculomegaly (VM) requires the balance of risks of neurological injury with premature delivery. The purpose of this study was to evaluate outcomes related to early elective delivery due to fetal VM at our institution.

METHODS

We retrospectively assessed 120 babies (2008-2012) with antenatally diagnosed fetal VM. Inclusion criteria for ("early") cohort were (1) elective delivery occurred for expedited neurosurgical intervention between 32 and 36 weeks EGA and (2) fetal VM noted on official antenatal ultrasound. The comparative "near term" cohort differed only in that delivery occurred at 37+ weeks EGA. Statistical significance for comparative analyses set a priori at p < 0.05.

RESULTS

Babies electively delivered early had a lower birthweight (p < 0.0001), greater ventricle width (p < 0.0001), and underwent initial CSF diversion sooner (p = 0.014). The early cohort (n = 22), compared to near term (n = 50), had a lower birthweight (p < 0.0001), greater ventricle width (p < 0.0001), and underwent initial CSF diversion sooner (p = 0.014). The early cohort required more repeat procedures: (45 vs. 22% p = 0.021), and VPS removals after VPS infections (41 vs. 12%, p = 0.010). Additionally, newborn respiratory failure (32 vs. 6%, p = 0.037) was more common. Finally, of four babies who died in the early cohort, 2/4 died for prematurity-associated pulmonary hypoplasia.

CONCLUSIONS

While early elective delivery for fetal VM expedites intervention for rapidly expanding ventricles, few benefits were identified. Our study concluded those infants that were delivered earlier had increased VPS infections, repeat neurosurgical procedures, and medical co-morbidities. A multi-institutional prospective observational study would be needed in order to confirm the clinical implications of such practice.

Surfactant and continuous positive airway pressure for the prevention of chronic lung disease: History, reality, and new challenges

The discovery of surfactant was one of the most significant research events to occur in the history of neonatology. Certainly, surfactant saved lives for premature infants who were otherwise considered non-viable. However, the prevention of chronic lung disease did not progress and it became clear that a significant portion of the help surfactant provides to the premature lung is counteracted by mechanical ventilation. A dilemma exists over the priorities in premature management to intubate and administer surfactant or not to intubate and support these infants non-invasively with the use of continuous positive airway pressure. A new hydrophilic surfactant preparation has been developed with the hope to enable the introduction of surfactant therapy without the need for tracheal intubation. Clinical trials on this product are currently in progress. This article provides the history and prospect of respiratory distress management in premature infants and evaluates the current evidence for non-invasive practices.

Prophylactic versus Early Rescue Surfactant Treatment in Preterm Infants Born at Less than 30 Weeks Gestation or with Birth Weight Less than or Equal 1,250 Grams

Prophylactic surfactant is known to be effective to reduce chronic lung disease in preterm infants compared with rescue surfactant treatment. In Korea, early prophylactic surfactant therapy was introduced in 2011. However, recently, the increased utilization of antenatal steroids and early stabilization through continuous positive airway pressure (CPAP) in the delivery room may have changed the risks and benefits of prophylactic surfactant therapy of infants at high risk of respiratory distress syndrome (RDS). We compared the effects and safety of prophylactic surfactant therapy (within 30 minutes after birth) and early selective surfactant therapy (within 3 hours after birth) in preterm infants born at < 30 weeks gestation or with birth weight ≤ 1,250 g. The clinical data of 193 infants in period 1 (from 2008 to 2010, early selective surfactant therapy group) were collected retrospectively; those of 191 infants in period 2 (from 2012 to 2014, prophylactic surfactant therapy group) were collected prospectively. Compared to period 1, the rate of intubation and surfactant use were significantly increased in period 2. The use of multiple doses of surfactant in period 2 was significantly increased compared with period 1. Despite more invasive and aggressive management in period 2, there was no difference in the duration of mechanical ventilation, the incidence of bronchopulmonary dysplasia (BPD) or death, and the risk of other adverse neonatal outcomes between the 2 groups. In conclusion, the benefit of prophylactic surfactant therapy in infants treated under current practices is no longer clear compared to early selective surfactant therapy.

A randomized controlled trial of the laryngeal mask airway for surfactant administration in neonates

OBJECTIVE

To compare the short-term efficacy of surfactant administration by laryngeal mask airway versus endotracheal tube.

METHODS

Preterm infants (28-35 weeks of gestational age), weighing 1kg or more, with respiratory distress syndrome, requiring nasal continuous positive airway pressure, with increased respiratory effort and/or fraction of inspired oxygen (FiO₂)≥0.40 to maintain oxygen saturation 91-95%, were randomized to receive surfactant by LMA following nCPAP or by ETT following mechanical ventilation (MV). The primary outcome was a clinical response defined as FiO₂≤0.30 three hours after surfactant. Secondary outcomes for LMA group were: need of surfactant retreatment during the first 24h, MV requirement, and presence of surfactant in gastric content.

RESULTS

Forty-eight patients were randomized; 26 in the LMA group and 22 in the ETT group. Six of 26 patients (23%) in the LMA group and five of 22 patients (22.7%) in the ETT group did not meet the primary outcome (p=0.977). Fourteen (53.8%) of the LMA patients were not intubated nor ventilated; 12 (46.1%) were ventilated: for surfactant failure (23%), for nCPAP failure (11.5%), and for late complications (11.5%). Groups were similar regarding prenatal status, birth conditions, and adverse events. No significant gastric content was found in 61.5% of the LMA patients. Oxygen and second dose surfactant requirements, arterial/alveolar ratio, and morbidities were similar among groups.

CONCLUSIONS

Surfactant administration by LMA showed short-term efficacy, with similar supplementary oxygen need compared to surfactant by ETT, and lower MV requirement. Further studies with larger sample size are necessary to confirm these results.

Optimization of Variable Ventilation for Physiology, Immune Response and Surfactant Enhancement in Preterm Lambs

Preterm infants often require mechanical ventilation due to lung immaturity including reduced or abnormal surfactant. Since cyclic stretch with cycle-by-cycle variability is known to augment surfactant release by epithelial cells, we hypothesized that such in vivo mechanotransduction improves surfactant maturation and hence lung physiology in preterm subjects. We thus tested whether breath-by-breath variability in tidal volume (V_T) in variable ventilation (VV) can be tuned for optimal performance in a preterm lamb model. Preterm lambs were ventilated for 3 h with conventional ventilation (CV) or two variants of VV that used a maximum V_T of 1.5 (VV1) or 2.25 (VV2) times the mean V_T. V_T was adjusted during ventilation to a permissive pCO₂ target range. Respiratory mechanics were monitored continuously using the forced oscillation technique, followed by postmortem bronchoalveolar lavage and tissue collection. Both VVs outperformed CV in blood gas parameters (pH, SaO₂, cerebral O₂ saturation). However, only VV2 lowered PaCO₂ and had a higher specific respiratory compliance than CV. VV2 also increased surfactant protein (SP)-B release compared to VV1 and stimulated its production compared to CV. The production and release of proSP-C however, was increased with CV compared to both VVs. There was more SP-A in both VVs than CV in the lung, but VV2 downregulated SP-A in the lavage, whereas SP-D significantly increased in CV in both the lavage and lung. Compared to CV, the cytokines IL-1β, and TNFα decreased with both VVs with less inflammation during VV2. Additionally, VV2 lungs showed the most homogeneous alveolar structure and least inflammatory cell infiltration assessed by histology. CV lungs exhibited over-distension mixed with collapsed and interstitial edematous regions with occasional hemorrhage. Following VV1, some lambs had normal alveolar structure while others were similar to CV. The IgG serum proteins in the lavage, a marker of leakage, were the highest in CV. An overall combined index of performance that included physiological, biochemical and histological markers was the best in VV2 followed by VV1. Thus, VV2 outperformed VV1 by enhancing SP-B metabolism resulting in open alveolar airspaces, less leakage and inflammation and hence better respiratory mechanics.

Surfactant reduced the mortality of neonates with birth weight ⩾1500 g and hypoxemic respiratory failure: a survey from an emerging NICU network

OBJECTIVE

We evaluated the efficacy of surfactant therapy and assisted ventilation on morbidity and mortality of neonates with birth weight (BW) ⩾1500 g and hypoxemic respiratory failure (HRF).

STUDY DESIGN

We retrospectively analyzed 5650 patients with BW ⩾1500 g for incidence, management and outcome of HRF, defined as acute hypoxemia requiring mechanical ventilation and/or nasal continuous positive airway pressure ⩾24 h. The patients were allocated into groups of moderate preterm (1735, 30.7%), late preterm (1431, 25.4%), early term (ETM, 986, 17.5%), full term (1390, 24.6%) and post term (79, 1.4%), with gestational age ⩽33, 34 to 36, 37 to 38, 39 to 41 and ⩾42 weeks, respectively.

RESULTS

In the five groups, 66.9, 42, 21.6, 12.8 and 5.1% had respiratory distress syndrome (RDS). For pneumonia/sepsis and meconium aspiration syndrome (MAS), the proportion was 13.8%, 25.4%, 38.0%, 52.5% and 76.0%, respectively. Surfactant was given to 21.9% (n=1238) of HRF and 51.2% (n=1108) of RDS. Survival rates of RDS were 82.2%, 87.8%, 84.5%, 77.1% and 75.0%, respectively (numbers needed to treat was 8 to 11 for surfactant benefit). Overall mortality rate of HRF was 21%, or 17.9%, 14.7%, 25.6%, 28.9% and 39.2%, respectively. Mortalities of MAS and pneumonia/sepsis were 29.4 and 27.6%. Relative risk of death was associated with initial disease severity, female gender, mechanical ventilation and congenital anomalies by multivariate logistic regression analysis.

CONCLUSION

Surfactant was effective for infants with RDS and BW ⩾1500 g, and different incidences and outcome of HRF among GA groups reflected standard of perinatal and respiratory care in emerging neonatal intensive care unit network.

The Future of Bronchopulmonary Dysplasia: Emerging Pathophysiological Concepts and Potential New Avenues of Treatment

Yearly more than 15 million babies are born premature (<37 weeks gestational age), accounting for more than 1 in 10 births worldwide. Lung injury caused by maternal chorioamnionitis or preeclampsia, postnatal ventilation, hyperoxia, or inflammation can lead to the development of bronchopulmonary dysplasia (BPD), one of the most common adverse outcomes in these preterm neonates. BPD patients have an arrest in alveolar and microvascular development and more frequently develop asthma and early-onset emphysema as they age. Understanding how the alveoli develop, and repair, and regenerate after injury is critical for the development of therapies, as unfortunately there is still no cure for BPD. In this review, we aim to provide an overview of emerging new concepts in the understanding of perinatal lung development and injury from a molecular and cellular point of view and how this is paving the way for new therapeutic options to prevent or treat BPD, as well as a reflection on current treatment procedures.

Providers' compliance with practice guidelines of prenatal and neonatal care to reduce neonatal mortality: 2004 versus 2012

Objective:

To evaluate providers' compliance with practice guidelines of prenatal and neonatal care in order to reduce neonatal mortality.

Methods:

Uncontrolled before-and-after study designed to evaluate changes that occurred between 2004 and 2012, after the interventions proposed by the Municipality Committee of Research on Child Deaths, Foetal and Maternal Death (COMAI) on the frequency of the process indicators for perinatal assistance improvement. A total of 254 patients were studied in 2004 and 259 patients in 2012.

Results:

During the study period, there was an increase of 65% in the use of prenatal corticosteroids among pregnant women in preterm labor with gestational age of ≤ 34 weeks (rate of use of 38.0 and 62.8% in 2004 and 2012, respectively; p < 0.001), 35% of increase in the use of surfactant among newborns with ≤ 34 weeks of gestational age (41.3 and 55.6% in 2004 and 2012, respectively; p = 0.025) and a reduction of 16% in the prevalence of hypothermia (70.8 and 59.4% in 2004 and 2012, respectively; p = 0.009) at the neonatal intensive care unit admission.

Conclusions:

Prenatal and neonatal care practices improved between 2004 and 2012. At the end of the study period, rates of use of antenatal steroids and surfactant were lower than figures reported internationally. Similarly, the frequency of hypothermia at the neonatal intensive care unit admission was higher than the occurrence observed in developed countries.

In vitro and in vivo comparison between poractant alfa and the new generation synthetic surfactant CHF5633

BACKGROUND

CHF5633 is a new generation synthetic surfactant containing both SP-B and SP-C analogues developed for the treatment of respiratory distress syndrome. Here, the optimal dose and its performance in comparison to the animal-derived surfactant poractant alfa were investigated.

METHODS

In vitro surfactant activity was determined by means of the Wilhelmy balance and the capillary surfactometer. The dose-finding study was performed in preterm rabbits with severe surfactant deficiency. CHF5633 doses ranging from 50 to 300 mg/kg were used. Untreated animals and animals treated with 200 mg/kg of poractant alfa were included for comparison.

RESULTS

In vitro, minimum surface tension (γ_min) was decreased from values above 70 to 0 mN/m by both surfactants, and they formed rapidly a film at the air-liquid interface. In vivo studies showed a clear dose-dependent improvement of lung function for CHF5633. The pulmonary effect of CHF5633 200 mg/kg dose was comparable to the pulmonary response elicited by 200 mg/kg of poractant alfa in preterm rabbits.

CONCLUSION

CHF5633 is as efficient as poractant alfa in our in vitro and in vivo settings. A clear dose-dependent improvement of lung function could be observed for CHF5633, with the dose of 200 mg/kg being the most efficient one.

Continuous Positive Airway Pressure Strategies with Bubble Nasal Continuous Positive Airway Pressure: Not All Bubbling Is the Same: The Seattle Positive Airway Pressure System

Premature neonates are predisposed to complications, including bronchopulmonary dysplasia (BPD). BPD is associated with long-term pulmonary and neurodevelopmental consequences. Noninvasive respiratory support with nasal continuous positive airway pressure (CPAP) has been recommended strongly by the American Academy of Pediatrics. However, CPAP implementation has shown at least a 50% failure rate. Enhancing nasal CPAP effectiveness may decrease the need for mechanical ventilation and reduce the incidence of BPD. Bubble nasal CPAP is better than nasal CPAP using mechanical devices and the bubbling provides air exchange in distal respiratory units. The Seattle PAP system reduces parameters that assess work of breathing.