Approaches to Interdisciplinary Care for Infants with Severe Bronchopulmonary Dysplasia: A Survey of the Bronchopulmonary Dysplasia Collaborative.

OBJECTIVE: Bronchopulmonary dysplasia (BPD) remains the most common late morbidity for extremely premature infants. Care of infants with BPD requires a longitudinal approach from the neonatal intensive care unit to ambulatory care though interdisciplinary programs. Current approaches for the development of optimal programs vary among centers. STUDY DESIGN: We conducted a survey of 18 academic centers that are members of the BPD Collaborative, a consortium of institutions with an established interdisciplinary BPD program. We aimed to characterize the approach, composition, and current practices of the interdisciplinary teams in inpatient and outpatient domains. RESULTS: Variations exist among centers, including composition of the interdisciplinary team, whether the team is the primary or consult service, timing of the first team assessment of the patient, frequency and nature of rounds during the hospitalization, and the timing of ambulatory visits postdischarge. CONCLUSION: Further studies to assess long-term outcomes are needed to optimize interdisciplinary care of infants with severe BPD. KEY POINTS: · Care of infants with BPD requires a longitudinal approach from the NICU to ambulatory care.. · Benefits of interdisciplinary care for children have been observed in other chronic conditions.. · Current approaches for the development of optimal interdisciplinary BPD programs vary among centers..

Prostanoids and their analogues for the treatment of pulmonary hypertension in neonates.

BACKGROUND: Persistent pulmonary hypertension of the newborn (PPHN) is a disease entity that describes a physiology in which there is persistence of increased pulmonary arterial pressure. PPHN is characterised by failure to adapt to a functional postnatal circulation with a fall in pulmonary vascular resistance. PPHN is responsible for impairment in oxygenation and significant neonatal mortality and morbidity. Prostanoids and their analogues may be useful therapeutic interventions due to their pulmonary vasodilatory and immunomodulatory effects. OBJECTIVES: Primary objective• To determine the efficacy and safety of prostanoids and their analogues (iloprost, treprostinil, and beraprost) in decreasing mortality and the need for extracorporeal membrane oxygenation (ECMO) among neonates with PHSecondary objective• To determine the efficacy and safety of prostanoids and their analogues (iloprost, treprostinil, and beraprost) in decreasing neonatal morbidity (necrotizing enterocolitis (NEC), chronic lung disease (CLD), retinopathy of prematurity (ROP), intraventricular hemorrhage (IVH), periventricular leukomalacia (PVL), length of hospital stay, and duration of mechanical ventilation) and improving neurodevelopmental outcomes among neonates with PHComparisons• Prostanoids and their analogues at any dosage or duration used to treat PPHN versus 'standard treatment without these agents', placebo, or inhaled nitric oxide (iNO) therapy• Prostanoids and their analogues at any dosage or duration used to treat refractory PPHN as an 'add-on' therapy to iNO versus iNO alone SEARCH METHODS: We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL; 2018, Issue 9), MEDLINE via PubMed (1966 to 16 September 2018), Embase (1980 to 16 September 2018), and the Cumulative Index to Nursing and Allied Health Literature (CINAHL; 1982 to 16 September 2018). We also searched clinical trials databases, conference proceedings of the Pediatric Academic Societies (1990 to 16 September 2018), and the reference lists of retrieved articles for randomized controlled trials and quasi-randomized trials. We contacted authors who have published in this field as discerned from the reference lists of identified clinical trials and review authors' personal files. SELECTION CRITERIA: Randomized and quasi-randomized controlled trials evaluating prostanoids or their analogues (at any dose, route of administration, or duration) used in neonates at any gestational age less than 28 days' postnatal age for confirmed or suspected PPHN. DATA COLLECTION AND ANALYSIS: We used the standard methods of Cochrane Neonatal to conduct a systematic review and to assess the methodological quality of included studies (neonatal.cochrane.org/en/index.html). Three review authors independently assessed the titles and abstracts of studies identified by the search strategy and obtained full-text versions for assessment if necessary. We designed forms for trial inclusion or exclusion and for data extraction. We planned to use the GRADE approach to assess the quality of evidence. MAIN RESULTS: We did not identify any eligible neonatal trials evaluating prostanoids or their analogues as sole agents in the treatment of PPHN. AUTHORS' CONCLUSIONS: Implications for practiceCurrently, no evidence shows the use of prostanoids or their analogues as pulmonary vasodilators and sole therapeutic agents for the treatment of PPHN in neonates (age 28 days or less).Implications for researchThe safety and efficacy of different preparations and doses and routes of administration of prostacyclins and their analogues in neonates must be established. Well-designed, adequately powered, randomized, multi-center trials are needed to address the efficacy and safety of prostanoids and their analogues in the treatment of PPHN. These trials should evaluate long-term neurodevelopmental and pulmonary outcomes, in addition to short-term outcomes.

Outcome and Treatment of Antenatally Diagnosed Nonimmune Hydrops Fetalis.

INTRODUCTION: The objectives of this study were to evaluate the outcome of nonimmune hydrops fetalis in an attempt to identify independent predictors of perinatal mortality. MATERIAL AND METHODS: A retrospective cohort study was conducted including all cases of nonimmune hydrops from two tertiary care centers. Perinatal outcome was evaluated after classifying nonimmune hydrops into ten etiological groups. We examined the effect of etiology, site of fluid accumulation, and gestational age at delivery on postnatal survival. Neonatal mortality and hospital discharge survival were compared between the expectant management and fetal intervention groups among those with idiopathic etiology. RESULTS: A total of 142 subjects were available for analysis. Generally, nonimmune hydrops carried 37% risk of neonatal mortality and 50% chance of survival to discharge, which varies markedly based on the underlying etiology. Ascites was an independent predictor of perinatal mortality (p value = 0.003). There was nonsignificant difference in neonatal mortality and hospital discharge survival among idiopathic cases that were managed expectantly versus those in whom fetal intervention was carried out. DISCUSSION: The outcome of nonimmune hydrops varies largely according to the underlying etiology and the presence of ascites is an independent risk factor for perinatal mortality. In our series, fetal intervention did not offer survival advantage among fetuses with idiopathic nonimmune hydrops.

Defining and predicting 'intrauterine fetal renal failure' in congenital lower urinary tract obstruction.

BACKGROUND: The aim of this study was to identify predictors of 'intrauterine fetal renal failure' in fetuses with severe congenital lower urinary tract obstruction (LUTO). METHODS: We undertook a retrospective study of 31 consecutive fetuses with a diagnosis of LUTO in a tertiary Fetal Center between April 2013 and April 2015. Predictors of 'intrauterine fetal renal failure' were evaluated in those infants with severe LUTO who had either a primary composite outcome measure of neonatal death in the first 24 h of life due to severe pulmonary hypoplasia or a need for renal replacement therapy within 7 days of life. The following variables were analyzed: fetal bladder re-expansion 48 h after vesicocentesis, fetal renal ultrasound characteristics, fetal urinary indices, and amniotic fluid volume. RESULTS: Of the 31 fetuses included in the study, eight met the criteria for 'intrauterine fetal renal failure'. All of the latter had composite poor postnatal outcomes based on death within 24 h of life (n = 6) or need for dialysis within 1 week of life (n = 2). The percentage of fetal bladder refilling after vesicocentesis at time of initial evaluation was the only predictor of 'intrauterine fetal renal failure' (cut-off <27 %, area under the time-concentration curve 0.86, 95 % confidence interval 0.68-0.99; p = 0.009). CONCLUSION: We propose the concept of 'intrauterine fetal renal failure' in fetuses with the most severe forms of LUTO. Fetal bladder refilling can be used to reliably predict 'intrauterine fetal renal failure', which is associated with severe pulmonary hypoplasia or the need for dialysis within a few days of life.

Are ultrasound renal aspects associated with urinary biochemistry in fetuses with lower urinary tract obstruction?

OBJECTIVE: To evaluate the association between ultrasonographic renal parameters and urine biochemistry in fetuses with lower urinary tract obstruction (LUTO). METHODS: Data were collected prospectively from 31 consecutive fetuses with LUTO that underwent vesicocentesis for fetal urinary biochemistry between April 2013 and September 2015. The following renal ultrasound markers were assessed immediately before the vesicocentesis: renal echogenicity, presence of cortical cysts, presence of findings suggestive of 'renal dysplasia' (hyperechogenic cystic kidneys with no cortical-medullary differentiation) and severe oligohydramnios (amniotic fluid < 5th percentile). The association of these parameters to the fetal urinary concentration of sodium, chloride, calcium, osmolality and beta2-microglobulin was investigated by logistic regression analysis. RESULTS: There was no relationship between any of the ultrasonographic fetal renal characteristics and fetal urinary biochemistry. CONCLUSIONS: In LUTO, the ultrasound appearance of the fetal kidneys and urinary biochemistry are not correlated. It may be better to take both ultrasound and biochemistry into account when evaluating fetuses with fetal LUTO. © 2016 John Wiley & Sons, Ltd.

Improving the Prediction of Neonatal Outcomes in Isolated Left-Sided Congenital Diaphragmatic Hernia by Direct and Indirect Sonographic Assessment of Liver Herniation.

OBJECTIVES: Liver herniation can be assessed sonographically by either a direct (liver-to-thoracic area ratio) or an indirect (stomach position) method. Our objective was to evaluate the utility of those methods to assess liver herniation for the prediction of neonatal outcomes in patients with isolated left-sided congenital diaphragmatic hernia (CDH). METHODS: We conducted a retrospective cohort study of all patients with CDH who had prenatal assessment and were delivered at Texas Children's Hospital between January 2004 and April 2014. The predictive value of sonographic parameters for mortality and the need for extracorporeal membrane oxygenation was evaluated by univariate, multivariate, and factor analysis and by receiver operating characteristics curves. RESULTS: A total of 77 fetuses with isolated left-sided CDH were analyzed. The lung-to-head ratio, liver-to-thorax ratio, and stomach position (according to the classifications of Kitano et al [Ultrasound Obstet Gynecol 2011; 37:277-282] and Cordier et al [J Matern Fetal Neonatal Med 2015; 28:190-195]) were significantly associated with both neonatal outcomes (P < .03). Significant correlations were observed between all of these sonographic parameters. A combination of the liver-to-thorax ratio and stomach position (Kitano) or stomach position (Cordier) with the lung-to-head ratio increased the area under the receiver operating characteristic curve of the lung-to-head ratio for mortality prediction (0.86 [95% confidence interval, 0.74-0.98], 0.83 [0.72-0.95], and 0.83 [0.74-0.92], respectively). CONCLUSIONS: Sonographic measurements of liver herniation (liver-to-thorax ratio and stomach position) are predictive of neonatal outcomes in isolated left-sided congenital diaphragmatic hernia. Our study shows that the combination of those sonographic measurements of liver herniation and lung size improves the accuracy of predicting mortality in those fetuses.

Lung development alterations in newborn mice after recovery from exposure to sublethal hyperoxia.

Exposure of newborn mice to hyperoxia arrests lung development, with resultant pathological characteristics similar to bronchopulmonary dysplasia in infants born prematurely. We tested the hypothesis that aberrations in lung development caused by 14 days of sublethal hyperoxia would be reversed during 14 days of recovery to room air (RA) when the concentration of oxygen exposure was weaned gradually. Newborn FVB mice were exposed to 85% oxygen or RA for 14 days. Weaning from hyperoxia was by either transfer directly into RA or a decrease in the concentration of oxygen by 10% per days. At 28 days, pups were euthanized, and the lungs were inflation fixed and assessed. At postnatal day 28, lungs of mice weaned abruptly from hyperoxia had fewer (6 ± 0.6 versus 10 ± 0.7; P < 0.001) alveoli per high-powered field and larger alveoli (4050 ± 207 versus 2305 ± 182 µm(2)) than animals weaned gradually; both hyperoxia-exposed groups were different from lungs obtained from air-breathing controls (20 ± 0.5 alveoli per high-powered field; P < 0.001). The results are consistent with the absence of catch-up alveolarization in this model and indicate that the long-term consequences of early exposures to hyperoxia merit closer examination. The effects of abrupt weaning to RA observed further suggest that weaning should be considered in experimental models of newborn exposure to hyperoxia.

Aryl hydrocarbon receptor is necessary to protect fetal human pulmonary microvascular endothelial cells against hyperoxic injury: Mechanistic roles of antioxidant enzymes and RelB.

Hyperoxia contributes to the development of bronchopulmonary dysplasia (BPD) in premature infants. Activation of the aryl hydrocarbon receptor (AhR) protects adult and newborn mice against hyperoxic lung injury by mediating increases in the expression of phase I (cytochrome P450 (CYP) 1A) and phase II (NADP(H) quinone oxidoreductase (NQO1)) antioxidant enzymes (AOE). AhR positively regulates the expression of RelB, a component of the nuclear factor-kappaB (NF-κB) protein that contributes to anti-inflammatory processes in adult animals. Whether AhR regulates the expression of AOE and RelB, and protects fetal primary human lung cells against hyperoxic injury is unknown. Therefore, we tested the hypothesis that AhR-deficient fetal human pulmonary microvascular endothelial cells (HPMEC) will have decreased RelB activation and AOE, which will in turn predispose them to increased oxidative stress, inflammation, and cell death compared to AhR-sufficient HPMEC upon exposure to hyperoxia. AhR-deficient HPMEC showed increased hyperoxia-induced reactive oxygen species (ROS) generation, cleavage of poly(ADP-ribose) polymerase (PARP), and cell death compared to AhR-sufficient HPMEC. Additionally, AhR-deficient cell culture supernatants displayed increased macrophage inflammatory protein 1α and 1ß, indicating a heightened inflammatory state. Interestingly, loss of AhR was associated with a significantly attenuated CYP1A1, NQO1, superoxide dismutase 1(SOD1), and nuclear RelB protein expression. These findings support the hypothesis that decreased RelB activation and AOE in AhR-deficient cells is associated with increased hyperoxic injury compared to AhR-sufficient cells.

Maternal morbidity in patients with morbidly adherent placenta treated with and without a standardized multidisciplinary approach.

OBJECTIVE: The purpose of this study was to test the hypothesis that a standardized multidisciplinary treatment approach in patients with morbidly adherent placenta, which includes accreta, increta, and percreta, is associated with less maternal morbidity than when such an approach is not used (nonmultidisciplinary approach). STUDY DESIGN: A retrospective cohort study was conducted with patients from 3 tertiary care hospitals from July 2000 to September 2013. Patients with histologically confirmed placenta accreta, increta, and percreta were included in this study. A formal program that used a standardized multidisciplinary management approach was introduced in 2011. Before 2011, patients were treated on a case-by-case basis by individual physicians without a specific protocol (nonmultidisciplinary group). Estimated blood loss, transfusion of packed red blood cells, intraoperative complications (eg, vascular, bladder, ureteral, and bowel injury), neonatal outcome, and maternal postoperative length of hospital stay were compared between the 2 groups. RESULTS: Of 90 patients with placenta accreta, 57 women (63%) were in the multidisciplinary group, and 33 women (37%) were in the nonmultidisciplinary group. The multidisciplinary group had more cases with percreta (P = .008) but experienced less estimated blood loss (P = .025), with a trend to fewer blood transfusions (P = .06), and were less likely to be delivered emergently (P = .001) compared with the nonmultidisciplinary group. Despite an approach of indicated preterm delivery at 34-35 weeks of gestation, neonatal outcomes were similar between the 2 groups. CONCLUSION: The institution of a standardized approach for patients with morbidly adherent placentation by a specific multidisciplinary team was associated with improved maternal outcomes, particularly in cases with more aggressive placental invasion (increta or percreta), compared with a historic nonmultidisciplinary approach. Our standardized approach was associated with fewer emergency deliveries.

Giant omphaloceles: surgical management and perinatal outcomes.

BACKGROUND: The purpose of this study was to describe the current management and outcomes of infants with omphalocele. METHODS: The medical records of all patients treated for omphalocele at a large children's hospital from January, 2003-February, 2014 were reviewed. Patients were classified as having an isolated omphalocele or omphalocele with minor or major associated anomalies. Prenatal data collected included fetal magnetic resonance imaging-based observed-to-expected total fetal lung volumes. Giant omphalocele (GO) was defined as >50% of liver in the omphalocele sac. RESULTS: Of 95 patients, 59 presented prenatally and had comprehensive fetal center evaluation. Of 82 live-born infants, 21 had chromosomal and 25 had major associated anomalies. No live-born baby with an isolated defect (n = 19) died, whereas mortality was 41% and 17% for those with major and minor anomalies, respectively (P = 0.006). Infants with major anomalies had significantly longer median length of intubation (36 versus 0 versus 0 d; P = 0.04) and hospital stay (157 versus 28.5 versus 18 d; P < 0.001) compared with those with minor or no anomalies. Of 40 infants with GO, the majority (85%) were managed surgically by delayed closure with a median age at repair of 10 mo (range, 3.4-23.6 mo). Six-month survival was 80%. None of the delayed repair patients required a later operative revision, whereas 2 of 5 with early repair did. CONCLUSIONS: The presence of associated anomalies is the strongest predictor of morbidity and mortality in fetuses or neonates with omphalocele. In patients with GO, delayed closure is associated with good outcomes, but larger, prospective studies comparing delayed to early closure are needed to determine the optimal timing of repair.

Revisiting outcomes of right congenital diaphragmatic hernia.

BACKGROUND: Studies comparing outcomes of right- and left-sided congenital diaphragmatic hernia (R-CDH and L-CDH) have yielded conflicting results. We hypothesized that R-CDH is associated with higher short-term pulmonary morbidity than L-CDH. METHODS: We reviewed all CDH patients at a tertiary children's hospital over 10 y. In prenatally diagnosed CDH, the observed-to-expected total fetal lung volume and percentage liver herniation (%LH) were calculated using fetal magnetic resonance imaging-based measurements. Outcomes were compared in patients with isolated CDH. Patients were subsequently matched by %LH to compare outcomes. RESULTS: Of 189 CDH patients, 37 (20.1 %) were R-CDH and 147 (79.9%) were L-CDH. Those with R-CDH were prenatally diagnosed at a significantly lower rate (40.5% versus 73.5%; P < 0.001) and later gestational age (26.5 ± 7.7 versus 22.6 ± 5.65 wk; P = 0.062). There was no difference in observed-to-expected total fetal lung volume between those with R-CDH and L-CDH (30.2 ± 11.1% versus 33.1 ± 14.2%; P = 0.471). Fetuses with R-CDH had a higher %LH than those with L-CDH (37.5 ± 14.1% versus 18.6 ± 12.2%; P < 0.001). Patients with isolated R-CDH had a higher need for extracorporeal membrane oxygenation than L-CDH (48% versus 27%; P = 0.055). There was no difference in duration of tracheal intubation, hospital stay, need for supplemental oxygen at 30-d of life or 6-mo mortality between groups. There was no difference in mortality and pulmonary morbidity when patients were matched by %LH. CONCLUSIONS: Compared to those with L-CDH, fetuses with R-CDH are less likely to be diagnosed prenatally and have a higher need for extracorporeal membrane oxygenation. The sidedness of the hernia defect was not associated with differences in short-term pulmonary morbidity in this large, contemporary single-institution experience of neonates with CDH.

Antecedent Predictors of Feeding Outcomes in Premature Infants With Protracted Mechanical Ventilation.

OBJECTIVES: The aim of the present study was to define risk factors associated with gastrostomy in premature infants receiving protracted mechanical ventilation (≥30 days). METHODS: Retrospective data collected on 170 preterm neonates (birth weight <1500 g) who received uninterrupted mechanical ventilation for ≥30 days were analyzed with logistic regression methods to predict the association of gastrostomy with cardiorespiratory, infectious, and neurological morbidities. RESULTS: A total of 32 of 170 infants had gastrostomy tubes. Including all of the covariates in 1 model, duration of cumulative ventilation (P < 0.001) and uninterrupted ventilation (P < 0.001), and ventriculoperitoneal shunt (P = 0.02) were significant predictors, whereas sepsis, intraventrical hemorrhage grade III or IV, and patent ductus arteriosus ligation were not. Respiratory severity score (mean airway pressure × fraction of inspired oxygen) calculated at 30 days of life was also a significant predictor (P = 0.01). CONCLUSIONS: In infants with protracted mechanical ventilation, the degree of respiratory support at 1 month of age, prolonged respiratory morbidity, and neuropathology are the significant predictors for gastrostomy.

Standardization of Sonographic Lung-to-Head Ratio Measurements in Isolated Congenital Diaphragmatic Hernia: Impact on the Reproducibility and Efficacy to Predict Outcomes.

OBJECTIVES: The purpose of this study was to evaluate the impact of standardization of the lung-to-head ratio measurements in isolated congenital diaphragmatic hernia on prediction of neonatal outcomes and reproducibility. METHODS: We conducted a retrospective cohort study of 77 cases of isolated congenital diaphragmatic hernia managed in a single center between 2004 and 2012. We compared lung-to-head ratio measurements that were performed prospectively in our institution without standardization to standardized measurements performed according to a defined protocol. RESULTS: The standardized lung-to-head ratio measurements were statistically more accurate than the nonstandardized measurements for predicting neonatal mortality (area under the receiver operating characteristic curve, 0.85 versus 0.732; P = .003). After standardization, there were no statistical differences in accuracy between measurements regardless of whether we considered observed-to-expected values (P > .05). Standardization of the lung-to-head ratio did not improve prediction of the need for extracorporeal membrane oxygenation (P> .05). Both intraoperator and interoperator reproducibility were good for the standardized lung-to-head ratio (intraclass correlation coefficient, 0.98 [95% confidence interval, 0.97-0.99]; bias, 0.02 [limits of agreement, -0.11 to +0.15], respectively). CONCLUSIONS: Standardization of lung-to-head ratio measurements improves prediction of neonatal outcomes. Further studies are needed to confirm these results and to assess the utility of standardization of other prognostic parameters.

Pulmonary capillary hemangiomatosis in a neonate with congenital diaphragmatic hernia.

Pulmonary capillary hemangiomatosis (PCH) is a rare cause of pulmonary hypertension (PHTN). We present a neonate with congenital diaphragmatic hernia (CDH) and concurrent PCH. Severe PHTN was unrelenting and death occurred at 4 months. Diagnosis of PCH is challenging in the setting of CDH and portends a poor prognosis.

The airway microbiome of intubated premature infants: characteristics and changes that predict the development of bronchopulmonary dysplasia.

BACKGROUND: Bronchopulmonary dysplasia (BPD) is associated with perinatal inflammatory triggers. Methods targeting bacterial rRNA may improve detection of microbial colonization in premature infants. We hypothesize that respiratory microbiota differs between preterm infants who develop BPD and those unaffected and correlates with inflammatory mediator concentrations. METHODS: Twenty-five infants, born at ≤32 wk of gestation and intubated in the first 24 h, were enrolled. Tracheal aspirates were obtained at intubation and on days 3, 7, and 28. Bacterial DNA was extracted, and 16S rRNA genes were amplified and sequenced. Concentrations of interleukins (IL-1ß, IL-6, IL-8, IL-10, and IL-12), tumor necrosis factor-α, interferon-γ, lipopolysaccharide (LPS), and lipoteichoic acid (LTA) were measured. Chorioamnionitis was diagnosed by histology. BPD was defined as an oxygen requirement at 36 wk postmenstrual age. RESULTS: Acinetobacter was the predominant genus in the airways of all infants at birth. Ten infants developed BPD and showed reduced bacterial diversity at birth. No differences were detected in bacterial diversity, cytokines, LPS, and LTA from infants with and without exposure to chorioamnionitis. CONCLUSION: The airways of premature infants are not sterile at birth. Reduced diversity of the microbiome may be an important factor in the development of BPD and is not associated with differences in inflammatory mediators.

Comparing characteristics and outcomes in infants with prenatal and postnatal diagnosis of esophageal atresia.

BACKGROUND: Previous studies of infants with esophageal atresia (EA) suggest those diagnosed prenatally have worse outcomes because of a higher incidence of associated anomalies. The purpose of this study was to compare characteristics and outcomes of infants with EA diagnosed after fetal center evaluation to those diagnosed postnatally. METHODS: The records of all neonates treated for EA at our institution from 2002-2012 were reviewed. Infants with a prenatal diagnosis of EA were compared with those postnatally diagnosed using chi-square and Student t-test as appropriate. RESULTS: Of 91 patients treated with EA during the study period, 15 (16%) were diagnosed prenatally at our fetal center. Although those prenatally diagnosed had a higher incidence of pure EA and polyhydramnios, the gestational age and birth weight in that group were similar to those diagnosed postnatally. There were no differences in outcomes between groups with regard to the incidence of major cardiac anomalies, surgical complications, hospital length of stay, and survival. CONCLUSIONS: Treatment at a tertiary care center provides excellent outcomes for all infants with EA, despite an 80% frequency of concurrent anomalies. Prenatal diagnosis of EA and attentive obstetric management of polyhydramnios decrease the risk for prematurity and prematurity-associated morbidity.

Managing established bronchopulmonary dysplasia without using routine blood gas measurements.

OBJECTIVE: Routine blood gas measurements are common in infants with severe bronchopulmonary dysplasia (sBPD) and are a noxious stimulus. We developed a guideline-driven approach to evaluate the care of infants with sBPD without routine blood gas sampling in the chronic phase of NICU care (after diagnosis at 36 weeks PMA). STUDY DESIGN: We examined blood gas utilization and outcomes in our sBPD inpatient care unit using data collected between 2014 and 2020. RESULTS: 485 sBPD infants met inclusion criteria, and 303 (62%) never had a blood gas obtained after 36 weeks PMA. In infants who had blood gas measurements, the median number of total blood gases per patient was only 4 (IQR 1-10). We did not identify adverse effects on hospital outcomes in patients without routine blood gas measurements. CONCLUSIONS: We found that patients with established BPD could be managed without routine blood gas analyses after 36 weeks PMA.

Functional deficiency of aryl hydrocarbon receptor augments oxygen toxicity-induced alveolar simplification in newborn mice.

Hyperoxia contributes to the development of bronchopulmonary dysplasia (BPD) in premature infants. New BPD is characterized as having alveolar simplification. We reported previously that aryl hydrocarbon receptor (AhR) deficiency increased susceptibility to hyperoxic lung injury in adult mice, and this was associated with decreased expression of cytochrome P450 1A enzymes and increased lung inflammation. Whether AhR protects newborn mice against hyperoxia-induced alveolar simplification is unknown. Thus, we tested the hypothesis that decreased activation of the pulmonary AhR augments hyperoxia-induced alveolar simplification and lung inflammation in newborn mice. Experimental groups included one-day old wild type (WT) and AhR dysfunctional (AhRd) mice exposed to 21% O2 (air) or 85% O2 (hyperoxia) for 14 days. Exposure of newborn WT mice to hyperoxia resulted in increased protein, enzyme and mRNA expression of the AhR-regulated lung cytochrome P450 1A1, NAD(P)H quinone oxidoreductase-1, and microsomal glutathione S-transferase 1 enzymes, suggesting that hyperoxia increases activation of the pulmonary AhR. On the other hand, in the AhRd mice, hyperoxia induced the AhR-regulated enzymes to a lesser extent probably due to the dysfunctional AhR in these mice. Alveolar simplification and lung inflammation was increased in mice exposed to hyperoxia compared with those exposed to air, and AhRd mice were more susceptible to hyperoxia-induced alveolar simplification and lung inflammation compared with WT mice. These findings suggest that decreased activation of the pulmonary AhR in newborn AhRd mice augments hyperoxia-induced alveolar simplification and lung inflammation in these mice.

Prenatal inflammation exacerbates hyperoxia-induced functional and structural changes in adult mice.

Maternally derived inflammatory mediators, such as IL-6 and IL-8, contribute to preterm delivery, low birth weight, and respiratory insufficiency, which are routinely treated with oxygen. Premature infants are at risk for developing adult-onset cardiac, metabolic, and pulmonary diseases. Long-term pulmonary consequences of perinatal inflammation are unclear. We tested the hypothesis that a hostile perinatal environment induces profibrotic pathways resulting in pulmonary fibrosis, including persistently altered lung structure and function. Pregnant C3H/HeN mice injected with LPS or saline on embryonic day 16. Offspring were placed in room air (RA) or 85% O(2) for 14 days and then returned to RA. Pulmonary function tests, microCTs, molecular and histological analyses were performed between embryonic day 18 and 8 wk. Alveolarization was most compromised in LPS/O(2)-exposed offspring. Collagen staining and protein levels were increased, and static compliance was decreased only in LPS/O(2)-exposed mice. Three-dimensional microCT reconstruction and quantification revealed increased tissue densities only in LPS/O(2) mice. Diffuse interstitial fibrosis was associated with decreased micro-RNA-29, increased transforming growth factor-ß expression, and phosphorylation of Smad2 during embryonic or early fetal lung development. Systemic maternal LPS administration in combination with neonatal hyperoxic exposure induces activation of profibrotic pathways, impaired alveolarization, and diminished lung function that are associated with prenatal and postnatal suppression of miR-29 expression.