Similar adverse outcome rates with high or low oxygen saturation targets in an area with low background mortality.

Background: Randomized controlled trials have indicated reduced mortality rates in very preterm infants assigned to high compared to low oxygen saturation (SpO2) target levels, accompanied by higher rates of retinopathy of prematurity and bronchopulmonary dysplasia. However, the benefit-to-harm ratio may depend on the local background mortality risk. We therefore aimed to quantify the risk-benefit ratios of different SpO2 target ranges in 10 tertiary newborn intensive care units (NICUs) in East Germany. Methods: In a retrospective multicenter study, 1,399 infants born between 2008 and 2012 at a gestational age between 24 0/7 and 27 6/7 weeks and with a birthweight below 1,250 g were grouped according to the hospital's target SpO2 range [high oxygen saturation group (HOSG) above 90%], low oxygen saturation group (LOSG) below 90%] and the compliance of units with their target SpO2 range. The association between neonatal morbidities, neurodevelopmental outcomes, selected treatment strategies, and target SpO2 ranges was calculated using chi-squared and Mann Whitney U tests. Results: Nine of the ten participating NICUs met their SpO2 target ranges. Five units were considered as HOSG, and five units were considered as LOSG. Necrotizing enterocolitis and intraventricular hemorrhage grade ≥ 2 occurred significantly more frequently in the HOSG than in the LOSG (8.4% vs. 5.1%, p = 0.02; and 26.6% vs. 17.7%, p < 0.001). No significant differences in the mortality rate and the rate of retinopathy of prematurity were found. Conclusion: In our patient population, a lower SpO2 target range was not associated with increased safety risks in extremely preterm infants. We cannot be sure that our outcome differences are associated with differences in oxygen saturations due to the retrospective study design and the differences in site practices.

A descriptive analysis of human milk dispensed by the Leipzig Donor Human Milk Bank for neonates between 2012 and 2019.

Background: Human milk banking has become an important aspect of Nutritional medicine. It is not just about the provision of mother's own milk (MOM) or donor human milk (DHM) in the hospital, but also a strategy to encourage breastfeeding in the clinical setting and beyond. Objective: To describe the feeding patterns of hospitalised infants including human milk dispensed by the Leipzig Donor Human Milk Bank (LMB). Design: A descriptive analysis of daily data on milk feeds dispensed by LMB for hospitalised infants distinguishing between MOM or DHM, either fresh or frozen, and raw/pasteurised milk from 2012-2019. Results: We included 2,562 infants with median hospitalisation of 23 days, for whom human milk was dispensed on median 76% of those days and other nutrition on the remaining days. Raw MOM and raw DHM comprised 52% and 8% of the dispensed milk, respectively. Dispensing exclusive DHM instead of MOM for at least one full day was required for 55% of the infants, mostly at the beginning but also later during hospitalisation. Exclusive raw DHM was dispensed on at least 1 day for 37% of the infants, in different birthweight strata <1,000 g: 10%, 1,000-1500 g: 11%, 1,500-2500 g: 13% and > 2,500 g: 3%. At discharge, MOM was dispensed for more than 60% of the infants. Conclusion: During an infant's hospital stay, LMB dispenses various human milk feeds with interspersed DHM resulting in complex intra-individual and time-variant feeding patterns. LMB dispenses raw MOM and especially raw DHM with the intention to retain the properties of human milk unlike a diet containing pasteurised DHM and/or formula. Although raw DHM comprises a small percentage of all dispensed milk, raw DHM is dispensed for a substantial portion of infants. Our results document that dispensing raw DHM, is possible in routine settings.

Imbalanced Inflammatory Responses in Preterm and Term Cord Blood Monocytes and Expansion of the CD14+CD16+ Subset upon Toll-like Receptor Stimulation.

Developmentally regulated features of innate immunity are thought to place preterm and term infants at risk of infection and inflammation-related morbidity. Underlying mechanisms are incompletely understood. Differences in monocyte function including toll-like receptor (TLR) expression and signaling have been discussed. Some studies point to generally impaired TLR signaling, others to differences in individual pathways. In the present study, we assessed mRNA and protein expression of pro- and anti-inflammatory cytokines in preterm and term cord blood (CB) monocytes compared with adult controls stimulated ex vivo with Pam3CSK4, zymosan, polyinosinic:polycytidylic acid, lipopolysaccharide, flagellin, and CpG oligonucleotide, which activate the TLR1/2, TLR2/6, TLR3, TLR4, TLR5, and TLR9 pathways, respectively. In parallel, frequencies of monocyte subsets, stimulus-driven TLR expression, and phosphorylation of TLR-associated signaling molecules were analyzed. Independent of stimulus, pro-inflammatory responses of term CB monocytes equaled adult controls. The same held true for preterm CB monocytes-except for lower IL-1ß levels. In contrast, CB monocytes released lower amounts of anti-inflammatory IL-10 and IL-1ra, resulting in higher ratios of pro-inflammatory to anti-inflammatory cytokines. Phosphorylation of p65, p38, and ERK1/2 correlated with adult controls. However, stimulated CB samples stood out with higher frequencies of intermediate monocytes (CD14+CD16+). Both pro-inflammatory net effect and expansion of the intermediate subset were most pronounced upon stimulation with Pam3CSK4 (TLR1/2), zymosan (TR2/6), and lipopolysaccharide (TLR4). Our data demonstrate robust pro-inflammatory and yet attenuated anti-inflammatory responses in preterm and term CB monocytes, along with imbalanced cytokine ratios. Intermediate monocytes, a subset ascribed pro-inflammatory features, might participate in this inflammatory state.

Association of response time and intermittent hypoxemia in extremely preterm infants.

AIM: To determine the relationship between medical staff's response time (RT) to oxygen saturation (SpO2 ) below 80% and the associated time from tactile intervention until SpO2 normalisation (CT). METHODS: Time-lapse video and continuous SpO2 were recorded for six consecutive 24 h periods. Regression analyses of RT and SpO2 in association with postmenstrual age (PMA), weight, infant sex and frequency of intermittent hypoxemia (IH). RESULTS: Five hundred and twelve hypoxemia episodes received tactile intervention in 20 extremely preterm infants (gestational age ≤28 weeks, birthweight <1500 g). Median RT was 20.5 s (IQR 16.63-25.50). RT increased with increased IH frequency (p = 0.023) independently of PMA and weight. SpO2 decreased by 3.7% with every 10 s RT (p = 0.039). Time until SpO2 normalisation was strongly associated with RT (ß = 0.58, p = 0.042). The association was amplified by lower PMA (p = 0.043). Female preterm infants experienced longer RT than males (p = 0.027). Because the total length of an IH is the sum of RT and CT, preterm infants with low PMA can reach a critical hypoxemia duration of >60 s, even with short RT. CONCLUSION: The RT is a critical factor that affects the overall time of IH treatments and the depth of desaturation. The consequences of a prolonged RT are worse for more immature preterm infants.

High-frequency ventilation in preterm infants and neonates.

High-frequency ventilation (HFV) has been used as a respiratory support mode for neonates for over 30 years. HFV is characterized by delivering tidal volumes close to or less than the anatomical dead space. Both animal and clinical studies have shown that HFV can effectively restore lung function, and potentially limit ventilator-induced lung injury, which is considered an important risk factor for developing bronchopulmonary dysplasia (BPD). Knowledge of how HFV works, how it influences cardiorespiratory physiology, and how to apply it in daily clinical practice has proven to be essential for its optimal and safe use. We will present important aspects of gas exchange, lung-protective concepts, clinical use, and possible adverse effects of HFV. We also discuss the study results on the use of HFV in respiratory distress syndrome in preterm infants and respiratory failure in term neonates. IMPACT: Knowledge of how HFV works, how it influences cardiorespiratory physiology, and how to apply it in daily clinical practice has proven to be essential for its optimal and safe use. Therefore, we present important aspects of gas exchange, lung-protective concepts, clinical use, and possible adverse effects of HFV. The use of HFV in daily clinical practice in lung recruitment, determination of the optimal continuous distending pressure and frequency, and typical side effects of HFV are discussed. We also present study results on the use of HFV in respiratory distress syndrome in preterm infants and respiratory failure in term neonates.

Incidence of Intermittent Hypoxemia Increases during Clinical Care and Parental Touch in Extremely Preterm Infants.

OBJECTIVES: An increased frequency of intermittent hypoxemia (IH) is associated with a higher risk for poor developmental outcomes, disability, or death in extremely preterm infants. The objective of the prFesent study is to quantify the effect of hands-on medical and parental interventions on the incidence of IH in extremely preterm infants. METHODS: An observational design with intraindividual comparisons was used. Blood oxygen saturation levels (SpO2) and time-lapse video were recorded. Frequency, duration, and time to occurrence of IH (SpO2 <80% for ≥10 s) were compared between nursing and medical care (NMC), health care by parents, skin-to-skin contact (SSC), touch in incubator, physiotherapy, and rest. Each infant was observed for six consecutive 24-h periods. Inclusion criteria were as follows: gestational age ≤28 weeks, birth weight <1500 g, postnatal age 0-6 weeks, gavage feeding, no severe illnesses or invasive procedures, no mechanical ventilation. RESULTS: The highest proportion of time with IH occurred during NMC (2.49%) and incubator touch (1.32%), the lowest during SSC (0.74%) and health care by parents (0.67%). IH frequency per hour was highest during NMC (2.95, IQR 1.19-4.01) and lowest during SSC (0.88, IQR 0.37-2.32, p < 0.001). While an increase in IH during NMC was expected, the high incidence during incubator touch was surprising. Parental touch in the incubator is intended to be soothing, not stressful. CONCLUSIONS: Future studies need to clarify how preterm infants process touch, which attributes of touch are fundamental trigger mechanisms of IH, and which handling strategies are most effective in lowering the incidence of IH during hands-on medical care.

Umbilical venous catheter- and peripherally inserted central catheter-associated complications in preterm infants with birth weight < 1250 g : Results from a survey in Austria and Germany.

BACKGROUND AND OBJECTIVE: Umbilical venous catheters (UVC) and peripherally inserted central catheters (PICC) are commonly used in preterm infants but have been associated with a number of serious complications. We performed a survey in Austria and Germany to assess the use of UVCs and PICCs in preterm infants with a birth weight < 1250 g and associated rates of catheter-related adverse events. METHODS: Electronic survey of participating centers of the NeoVitaA trial. Main outcome parameter was the reported rates of UVC- and PICC-associated complications (infection, thrombosis, emboli, organ injury, arrhythmia, dislocation, miscellaneous). RESULTS: In total, 20 neonatal intensive care units (NICU) providing maximal intensive care in Austria and Germany (level I) were contacted, with a senior neonatologist response rate of 12/20 (60%). The reported rates for UVC with a dwell time of 1-10 days were bacterial infection: 4.2 ± 3.4% (range 0-10%); thrombosis: 7.3 ± 7.1% (0-20%); emboli: 0.9 ± 2.0% (0-5%); organ injury: 1.1 ± 1.9% (0-5%); cardiac arrhythmia: 2.2 ± 2.5% (0-5%); and dislocation: 5.4 ± 8.7% (0-30%); and for PICCs with a dwell time of 1-14 days bacterial infection: 15.0 ± 3.4% (range 2.5-30%); thrombosis; 4.3 ± 3.5% (0-10%); emboli: 0.8 ± 1.6% (0-5%); organ injury: 1.5 ± 2.3% (0-5%); cardiac arrhythmia: 1.5 ± 2.3% (0-5%), and dislocation: 8.5 ± 4.6% (0-30%). CONCLUSION: The catheter-related complication rates reported in this survey differed between UVCs and PICCs and were higher than those reported in the literature. To generate more reliable data on this clinically important issue, we plan to perform a large prospective multicenter randomized controlled trial investigating the non-inferiority of a prolonged UVC dwell time (up to 10 days) against the early change (up to 5 days) to a PICC.

The Value of Perinatal Factors, Blood Biomarkers and Microbiological Colonization Screening in Predicting Neonatal Sepsis.

Background: Neonatal sepsis is one of the most important causes of elevated morbidity and mortality rates in neonatal intensive care units worldwide. While the clinical manifestations of neonatal sepsis tend to be nonspecific, its rapid development and life-threatening potential call for reliable markers for early detection. Methods: We conducted a retrospective single-center study including all neonates suspected of having developed neonatal sepsis from 2013 to 2016. Perinatal and clinical characteristics as well as microbiological and laboratory findings were evaluated. Neonatal sepsis was defined as either culture-proven sepsis (positive blood culture) or clinical sepsis (at least one symptom and elevated C-reactive protein (CRP) concentrations within 72 h with negative blood culture). We further differentiated between early-onset (EOS) and late-onset (LOS) sepsis. Results: Microbiological colonization screening by throat and rectal swabs frequently did not detect the organism that subsequently caused the sepsis. Depending on the age of the newborn with sepsis (EOS or LOS), associations between different anamnestic and clinical factors (prenatal or postnatal ones) were found. In particular, the central−peripheral temperature difference showed a strong association with LOS. Laboratory results useful for the early detection of neonatal sepsis included interleukin-6 (IL-6) and CRP concentrations. Conclusions: Elevated IL-6 >100 ng/L was a strong marker for neonatal sepsis. When choosing the antibiotics for treatment, data from microbiological colonization screening should be considered but not solely relied on. Some indicators of infection also depended on postnatal age.

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.

Albumin Stimulates Epithelial Na+ Transport and Barrier Integrity by Activating the PI3K/AKT/SGK1 Pathway.

Albumin is a major serum protein and is frequently used as a cell culture supplement. It is crucially involved in the regulation of osmotic pressure and distribution of fluid between different compartments. Alveolar epithelial Na+ transport drives alveolar fluid clearance (AFC), enabling air breathing. Whether or not albumin affects AFC and Na+ transport is yet unknown. We therefore determined the acute and chronic effects of albumin on Na+ transport in fetal distal lung epithelial (FDLE) cells and the involved kinase pathways. Chronic BSA treatment strongly increased epithelial Na+ transport and barrier integrity in Ussing chambers. BSA did not elevate mRNA expression of Na+ transporters in FDLE cells after 24 h. Moreover, acute BSA treatment for 45 min mimicked the chronic effects. The elevated Na+ transport was caused by an increased maximal ENaC activity, while Na,K-ATPase activity remained unchanged. Acute and chronic BSA treatment lowered membrane permeability, confirming the increased barrier integrity observed in Ussing chambers. Western blots demonstrated an increased phosphorylation of AKT and SGK1, and PI3K inhibition abolished the stimulating effect of BSA. BSA therefore enhanced epithelial Na+ transport and barrier integrity by activating the PI3K/AKT/SGK1 pathway.

Association of Administration of Surfactant Using Less Invasive Methods With Outcomes in Extremely Preterm Infants Less Than 27 Weeks of Gestation.

Importance: The inclusion of less invasive surfactant administration (LISA) in the care of preterm infants has been found to be beneficial for respiratory outcomes. Recently, the OPTIMIST trial found higher mortality rates in the subgroup of infants born at 25 to 26 weeks' gestational age (GA) who received surfactant treatment while spontaneously breathing. Objective: To analyze outcomes among LISA-exposed, highly vulnerable babies born at less than 27 weeks' GA within the large-scale observational cohort of the German Neonatal Network. Design, Setting, and Participants: In this cohort study of data from 68 tertiary level neonatal intensive care units in Germany of infants born between 22 weeks 0 days to 26 weeks 6 days of gestation between April 1, 2009, and December 31, 2020, short-term outcomes among infants receiving LISA vs infants not receiving LISA were compared. Exposure: Use of LISA within the first 72 hours of life. Main Outcomes and Measures: The main outcomes were rates of LISA use, use of mechanical ventilation within the first 72 hours (considered failure of LISA), and association of LISA with outcomes, including death from all causes, bronchopulmonary dysplasia (BPD), death and BPD combined, pneumothorax, retinopathy of prematurity, intracerebral hemorrhage, and periventricular leukomalacia. To address potential confounding factors, multivariate logistic regression models were used. Results: A total of 6542 infants (3030 [46.3%] female and 3512 [53.7%] male; mean [SD] GA, 25.3 (1.1) weeks; mean [SD] birth weight, 715 [180] g) were analyzed; 2534 infants (38.7%) received LISA, which was most frequently given quasi-prophylactically during delivery room management. Among the infants who received LISA, 1357 (53.6%) did not require mechanical ventilation in the first 72 hours compared with 331 infants (8.3%) of 4008 who did not receive LISA. In a multivariate logistic regression model that adjusted for GA, small-for-GA status, sex, multiple birth, inborn status, antenatal steroid use, and maximum fraction of inspired oxygen in the first 12 hours of life, LISA was associated with reduced risks of all-cause death (odds ratio [OR], 0.74; 95% CI, 0.61-0.90; P = .002), BPD (OR, 0.69; 95% CI, 0.62-0.78; P < .001), and BPD or death (OR, 0.64; 95% CI, 0.57-0.72; P < .001) compared with infants without LISA exposure. Conclusions and Relevance: The results of this long-term multicenter cohort study suggest that LISA may be associated with reduced risks of adverse outcomes in extremely preterm infants.

Population-Based Outcome Data of Extremely Preterm Infants in Germany during 2010-2017.

BACKGROUND AND OBJECTIVE: Results of five randomized controlled trials (RCT) sequentially published in 2010-2013 suggested that aiming for higher, as opposed to lower oxygen saturation targets, reduces rates of mortality in infants <28 weeks of gestation, while increasing rates of severe retinopathy of prematurity (ROP). Two further RCTs published in 2011 and 2015 demonstrated that avoiding endotracheal intubation by minimally invasive surfactant administration reduces respiratory morbidity. Assuming that such data are likely to affect clinical practice and ultimate outcome, we analyzed population-level results in extremely preterm infants born across Germany during 2010-2017. METHODS: We used mandatory German quality surveillance data to compare mortality and morbidities in preterm infants born between 24 weeks 0 days and 27 weeks 6 days of gestation in 2010-2013 versus 2014-2017. RESULTS: Mortality decreased from 15.1% (1,366/9,058) in 2010-2013 to 12.7% (1,385/10,924) in 2014-2017, risk ratio (RR) 0.845 (95% confidence interval [CI], 0.784-0.901). Rates of severe ROP (≥grade 3) per survivor increased from 12.1% (930/7,692) to 13.3% (1.269/9,539), RR 1.100 (95% CI: 1.017-1.191). The lowest mortality and highest ROP rates were found in infants born in 2014. There was no change in rates of necrotizing enterocolitis, while those of bronchopulmonary dysplasia (BPD) decreased steadily between 2010 and 2017, alongside the increased proportion of infants who were never intubated. CONCLUSIONS: There was a moderate decline in mortality, an insignificant increase in severe ROP, and a steady decline of BPD in Germany during 2010-2017. Avoiding endotracheal intubation may have contributed to lowered BPD rates.

Y It Matters-Sex Differences in Fetal Lung Development.

Within this review, sex-specific differences in alveolar epithelial functions are discussed with special focus on preterm infants and the respiratory disorders associated with premature birth. First, a short overview about fetal lung development, the challenges the lung faces during perinatal lung transition to air breathing and respiratory distress in preterm infants is given. Next, clinical observations concerning sex-specific differences in pulmonary morbidity of human preterm infants are noted. The second part discusses potential sex-specific causes of pulmonary complications, including pulmonary steroid receptors and local lung steroid metabolism. With regard to pulmonary steroid metabolism, it is important to highlight which steroidogenic enzymes are expressed at which stage during fetal lung development. Thereafter, we review the knowledge concerning sex-specific aspects of lung growth and maturation. Special focus is given to alveolar epithelial Na+ transport as a driver of perinatal lung transition and the sex differences that were noted in this process.

Evaluation of a diluted lipid emulsion solution as a lubricant for improved peripherally inserted central catheter guidewire removal in a neonatal population.

BACKGROUND: Medical management of neonates is often established upon safe and reliable vascular access, frequently utilized to provide physiological monitoring, parenteral and supportive treatments, and diagnostic and/or procedural purposes. For this, peripherally inserted central catheters (PICCs) are often used to provide safe vascular access and infusion-related therapies in the neonatal intensive care (NICU) setting. PURPOSE: Difficult PICC guidewire removal is understood to cause catheter damage, causing luminal rupture or possible breakage of the catheter or guidewire itself. The aim of this study was to assess and compare the incidence of therapy failures with use of a preflush fluid using normal saline (NSS) versus a diluted lipid solution (DLS) prior to device insertion, to assist with guidewire removal and prevent unnecessary catheter damage. METHOD AND SETTING: A retrospective, observational study was performed in the Neonatal Intensive Care Unit (NICU) of the Women's Wellness and Research Centre, Hamad Medical Corporation, Qatar. This single site study included 507 neonates who required intravenous therapy administered via a PICC during the study period. RESULTS: Results demonstrated the use of a diluted lipid solution preflush (DLS) resulted in significantly lesser failures, when compared with the control group (NSS). This highlights a clinical significance after adjusting for day of insertion, gestational age, birth weight and catheter type. CONCLUSION: DLS preflush demonstrated a benefit over the use of a NSS preflush to enhance PICC guidewire removal in neonatal patients in the NICU. The risk for development of maintenance-related complications leading to premature device removal decreased significantly if the DLS preflush was used. During the study period, no complications related to the use of a lipid preflush solution were identified. IMPLICATIONS FOR PRACTICE AND RESEARCH: This may be the first study published investigating and supporting guidewire removal enhancement by using a diluted lipid/saline preflush solution. When the requirement for vascular access is most pertinent in the neonate, using a diluted lipid preflush may provide an effective method to assist in guidewire removal to prevent malposition and vascular device complications in the neonatal population.

Development and Functional Characterization of Fetal Lung Organoids.

Preterm infants frequently suffer from pulmonary complications due to a physiological and structural lung immaturity resulting in significant morbidity and mortality. Novel in vitro and in vivo models are required to study the underlying mechanisms of late lung maturation and to facilitate the development of new therapeutic strategies. Organoids recapitulate essential aspects of structural organization and possibly organ function, and can be used to model developmental and disease processes. We aimed at generating fetal lung organoids (LOs) and to functionally characterize this in vitro model in comparison to primary lung epithelial cells and lung explants ex vivo. LOs were generated with alveolar and endothelial cells from fetal rat lung tissue, using a Matrigel-gradient and air-liquid-interface culture conditions. Immunocytochemical analysis showed that the LOs consisted of polarized epithelial cell adhesion molecule (EpCAM)-positive cells with the apical membrane compartment facing the organoid lumen. Expression of the alveolar type 2 cell marker, RT2-70, and the Club cell marker, CC-10, were observed. Na+ transporter and surfactant protein mRNA expression were detected in the LOs. First time patch clamp analyses demonstrated the presence of several ion channels with specific electrophysiological properties, comparable to vital lung slices. Furthermore, the responsiveness of LOs to glucocorticoids was demonstrated. Finally, maturation of LOs induced by mesenchymal stem cells confirmed the convenience of the model to test and establish novel therapeutic strategies. The results showed that fetal LOs replicate key biological lung functions essential for lung maturation and therefore constitute a suitable in vitro model system to study lung development and related diseases.

Epidermal growth factor strongly affects epithelial Na+ transport and barrier function in fetal alveolar cells, with minor sex-specific effects.

Male sex remains an independent risk factor for respiratory distress syndrome (RDS) in preterm infants. Insufficient Na+ transport-mediated alveolar fluid clearance contributes to RDS development and we previously demonstrated sex-specific differences in Na+ transport. The epidermal growth factor (EGF) is important during fetal lung development with possible influence on Na+ transport. Sex-specific effects of EGF during surfactant synthesis were shown. We thus determined whether EGF exerts sex-specific effects on Na+ transport in fetal alveolar cells. We analyzed sex-specific fetal distal lung epithelial (FDLE) cells exposed to EGF and related ligands with Ussing chambers, RT-qPCR and Western blots. EGF strongly reduced the epithelial Na+ channel (ENaC) mRNA levels in both male and female FDLE cells. This was corroborated by a markedly reduced ENaC activity, while amiloride-insensitive pathways as well as barrier function were raised by EGF. In contrast to chronic effects, acute effects of EGF were sex-specific, because Na+ transport was reduced only in males. AKT phosphorylation was elevated only in female cells, while pERK1/2 was increased in both male and female cells. EGF showed certain sex- and time-dependent effects in FDLE cells. Nevertheless, the results suggest that EGF is an unlikely cause for the sex-specific differences in Na+ transport.

The role of early-onset-sepsis in the neurodevelopment of very low birth weight infants.

AIMS: The study investigated a putative association between early-onset-sepsis (EOS) and poor neurodevelopmental outcomes at 2 years corrected age in very low birth weight infants. METHODS: This was a single-center cohort study on infants weighing less than 1500 g with a gestational age below 35 weeks at birth born between 2008 and 2011. Neurodevelopmental outcomes were assessed at follow-up with the Bayley Scales of Infant Development-II. EOS was defined as either culture-proven EOS or clinical EOS using blood culture, CrP levels, and clinical symptoms and treatment. Neurodevelopmental impairment (NDI) was defined as one or more of the following: Mental Developmental Index (MDI) and/or Psychomotor Developmental Index (PDI) scores lower than 70; presence of cerebral palsy. RESULTS: Of 405 eligible newborns in the study period 166 were included. Two had culture-proven and 29 clinical EOS. Median MDI scores in patients with EOS were 96 (IQR: 86-106) and in the control group 94 (84-106, p = 0.77). PDI scores in patients with EOS were 96 (86-106) and in the control group 99,5 (92-103, p = 0.03). Of infected patients 7/31 (24%) showed NDI as defined, whereas only 11/135 (8%) showed NDI in the control group (OR 3.3, p = 0.03). Multiple regression analyses identified chorioamnionitis and poor CRIB-Scores as individual risk factors for MDI or PDI values < 70. CONCLUSION: In our study, EOS among VLBW-infants significantly impaired the neurodevelopment at 2 years corrected age. As shown in previous reports infection continues to be a problem and strategies for a reduction need further improvement.

Paracrine stimulation of perinatal lung functional and structural maturation by mesenchymal stem cells.

BACKGROUND: Mesenchymal stem cells (MSCs) were shown to harbor therapeutic potential in models of respiratory diseases, such as bronchopulmonary dysplasia (BPD), the most common sequel of preterm birth. In these studies, cells or animals were challenged with hyperoxia or other injury-inducing agents. However, little is known about the effect of MSCs on immature fetal lungs and whether MSCs are able to improve lung maturity, which may alleviate lung developmental arrest in BPD. METHODS: We aimed to determine if the conditioned medium (CM) of MSCs stimulates functional and structural lung maturation. As a measure of functional maturation, Na+ transport in primary fetal distal lung epithelial cells (FDLE) was studied in Ussing chambers. Na+ transporter and surfactant protein mRNA expression was determined by qRT-PCR. Structural maturation was assessed by microscopy in fetal rat lung explants. RESULTS: MSC-CM strongly increased the activity of the epithelial Na+ channel (ENaC) and the Na,K-ATPase as well as their mRNA expression. Branching and growth of fetal lung explants and surfactant protein mRNA expression were enhanced by MSC-CM. Epithelial integrity and metabolic activity of FDLE cells were not influenced by MSC-CM. Since MSC's actions are mainly attributed to paracrine signaling, prominent lung growth factors were blocked. None of the tested growth factors (VEGF, BMP, PDGF, EGF, TGF-ß, FGF, HGF) contributed to the MSC-induced increase of Na+ transport. In contrast, inhibition of PI3-K/AKT and Rac1 signaling reduced MSC-CM efficacy, suggesting an involvement of these pathways in the MSC-CM-induced Na+ transport. CONCLUSION: The results demonstrate that MSC-CM strongly stimulated functional and structural maturation of the fetal lungs. These effects were at least partially mediated by the PI3-K/AKT and Rac1 signaling pathway. Thus, MSCs not only repair a deleterious tissue environment, but also target lung cellular immaturity itself.

Effects of Liberal vs Restrictive Transfusion Thresholds on Survival and Neurocognitive Outcomes in Extremely Low-Birth-Weight Infants: The ETTNO Randomized Clinical Trial.

Importance: Red blood cell transfusions are commonly administered to infants weighing less than 1000 g at birth. Evidence-based transfusion thresholds have not been established. Previous studies have suggested higher rates of cognitive impairment with restrictive transfusion thresholds. Objective: To compare the effect of liberal vs restrictive red blood cell transfusion strategies on death or disability. Design, Setting, and Participants: Randomized clinical trial conducted in 36 level III/IV neonatal intensive care units in Europe among 1013 infants with birth weights of 400 g to 999 g at less than 72 hours after birth; enrollment took place between July 14, 2011, and November 14, 2014, and follow-up was completed by January 15, 2018. Interventions: Infants were randomly assigned to liberal (n = 492) or restrictive (n = 521) red blood cell transfusion thresholds based on infants' postnatal age and current health state. Main Outcome and Measures: The primary outcome, measured at 24 months of corrected age, was death or disability, defined as any of cognitive deficit, cerebral palsy, or severe visual or hearing impairment. Secondary outcome measures included individual components of the primary outcome, complications of prematurity, and growth. Results: Among 1013 patients randomized (median gestational age at birth, 26.3 [interquartile range {IQR}, 24.9-27.6] weeks; 509 [50.2%] females), 928 (91.6%) completed the trial. Among infants in the liberal vs restrictive transfusion thresholds groups, respectively, incidence of any transfusion was 400/492 (81.3%) vs 315/521 (60.5%); median volume transfused was 40 mL (IQR, 16-73 mL) vs 19 mL (IQR, 0-46 mL); and weekly mean hematocrit was 3 percentage points higher with liberal thresholds. Among infants in the liberal vs restrictive thresholds groups, the primary outcome occurred in 200/450 (44.4%) vs 205/478 (42.9%), respectively, for a difference of 1.6% (95% CI, -4.8% to 7.9%; P = .72). Death by 24 months occurred in 38/460 (8.3%) vs 44/491 (9.0%), for a difference of -0.7% (95% CI, -4.3% to 2.9%; P = .70), cognitive deficit was observed in 154/410 (37.6%) vs 148/430 (34.4%), for a difference of 3.2% (95% CI, -3.3% to 9.6%; P = .47), and cerebral palsy occurred in 18/419 (4.3%) vs 25/443 (5.6%), for a difference of -1.3% (95% CI, -4.2% to 1.5%; P = .37), in the liberal vs the restrictive thresholds groups, respectively. In the liberal vs restrictive thresholds groups, necrotizing enterocolitis requiring surgical intervention occurred in 20/492 (4.1%) vs 28/518 (5.4%); bronchopulmonary dysplasia occurred in 130/458 (28.4%) vs 126/485 (26.0%); and treatment for retinopathy of prematurity was required in 41/472 (8.7%) vs 38/492 (7.7%). Growth at follow-up was also not significantly different between groups. Conclusions and Relevance: Among infants with birth weights of less than 1000 g, a strategy of liberal blood transfusions compared with restrictive transfusions did not reduce the likelihood of death or disability at 24 months of corrected age. Trial Registration: ClinicalTrials.gov Identifier: NCT01393496.

Permissive Hypercapnia Results in Decreased Functional Vessel Density in the Skin of Extremely Low Birth Weight Infants.

BACKGROUND: Ventilator-induced lung injury with subsequent bronchopulmonary dysplasia remains an important issue in the care of extremely low-birth-weight infants. Permissive hypercapnia has been proposed to reduce lung injury. Hypercapnia changes cerebral perfusion, but its influence on the peripheral microcirculation is unknown. METHODS: Data were collected from 12 infants, who were randomized to a permissive high PCO2 target group (HTG) or a control group (CG). Inclusion criteria were birth weight between 400 and 1,000 g, gestational age from 23 to 28 6/7 weeks, intubation during the first 24 h of life, and no malformations. The PCO2 target range was increased stepwise in both groups for weaning and was always 15 mmHg higher in the HTG than in the CG. Skin microvascular parameters were assessed non-invasively with sidestream dark field imaging on the inner side of the right arm every 24 h during the first week of life and on the 14th day of life. RESULTS: Infants in the HTG had significantly higher max. PCO2 exposure, which was associated with a significantly and progressively reduced functional vessel density (FVD, p < 0.01). Moreover, there were significant differences in the diameter distribution over time, with HTG subjects having fewer small vessels but more large vessels. CONCLUSION: High PCO2 levels significantly impaired peripheral microcirculation in preterm infants, as shown by a decreased FVD, presumably secondary to peripheral vasoconstriction. ISRCTN: 56143743.