Neonatal bronchopulmonary dysplasia increases neuronal apoptosis in the hippocampus through the HIF-1α and p53 pathways

Neonatal bronchopulmonary dysplasia (BPD) might lead to an increased risk for brain injury. The present study aims to investigate the effects of neonatal BPD on neuronal apoptosis in the hippocampus and cognitive function and to explore the underlying mechanisms. The results revealed that BPD model rat pups exhibited more apoptotic cells in the hippocampus and longer escape latencies in the Morris maze test. Both the caspase-dependent and caspase-nondependent signal pathways were activated. Further examinations showed an elevated p53 level by BPD via HIF-1α induction, while the caspase-3 in the hippocampus was suppressed by both HIF-1α and p53 inhibitor. These findings suggested that neonatal BPD caused impaired cognitive function and neuron apoptosis in hippocampus via p53 and HIF-1α. Although the precise mechanism requires further investigation, this study provided new evidence for and an explanation of the impaired CNS developmental outcomes of BPD.

Correlation of radiographic thoracic area and oxygenation impairment in bronchopulmonary dysplasia

We hypothesized that radiographically-assessed hyperinflation in bronchopulmonary dysplasia (BPD) is related to the degree of oxygenation impairment. Our objective was to explore the relation of chest radiographic thoracic area (CRTA) with right-to-left shunt, right shift of the oxyhemoglobin dissociation curve and ventilation/perfusion ratio (VA/Q) in infants with BPD. Twenty-two infants born at median (IQR) gestation of 26 (24-28) weeks with BPD were prospectively studied at 39 (30-69) days. Inspired oxygen (FiO2) was varied to obtain transcutaneous oxygen saturation (SpO2) values between 85 and 96%. Shunt, shift and VA/Q were derived by plotting and analysing pairs of SpO2 and FiO2. CRTA was measured by free hand-tracing the perimeter of the thoracic area in anterio-posterior chest radiographs. Median (IQR) shunt was 8 (1-14)%, shift was 13 (11-19)kPa and VA/Q 0.42 (0.30-0.48). Median (IQR) CRTA/kg was 2495 (1962-2838)mm(2) and was significantly related to shift (r=0.674, p<0.001), VA/Q (r=-0.633, p<0.001), weight at study (r=-0.457, p=0.003) and day of life (r=-0.406, p=0.009), but not to shunt. CRTA in BPD is significantly related to oxygenation impairment as quantified by shift and VA/Q. CRTA can be used as a simple radiographic test to quantify BPD severity.

Developmentally determined reduction in CD31 during gestation is associated with CD8+ T cell effector differentiation in preterm infants

Homeostatic T cell proliferation is more robust during human fetal development. In order to understand the relative effect of normal fetal homeostasis and perinatal exposures on CD8+ T cell behavior in PT infants, we characterized umbilical cord blood CD8+ T cells from infants born between 23-42weeks gestation. Subjects were recruited as part of the NHLBI-sponsored Prematurity and Respiratory Outcomes Program. Cord blood from PT infants had fewer naïve CD8+ T cells and lower regulatory CD31 expression on both naïve and effector, independent of prenatal exposures. CD8+ T cell in vitro effector function was greater at younger gestational ages, an effect that was exaggerated in infants with prior inflammatory exposures. These results suggest that CD8+ T cells earlier in gestation have loss of regulatory co-receptor CD31 and greater effector differentiation, which may place PT neonates at unique risk for CD8+ T cell-mediated inflammation and impaired T cell memory formation.

Biomarkers in neonatology: the new "omics" of bronchopulmonary dysplasia

Bronchopulmonary dysplasia (BPD) is a complex disorder resulting from gene-environmental interactions. An improved understanding of the pathogenesis of this most common chronic lung disease in infants has been made by utilizing animal models and correlating with human data. Currently, while some (vitamin A, caffeine) pharmacotherapeutic options are being utilized to ameliorate this condition, there is still no specific or effective treatment for BPD. It would be helpful for prognostication and targeted potential novel therapeutic strategies to identify those babies accurately who are at risk for developing this disease. A reliable biomarker would have the capacity to be detected in the initial phase of the disease, to allow early interventions to avoid or minimize the detrimental effects of the disease. This review will focus on human studies performed with the "omic" techniques, specifically genomics, epigenomics, microbiomics, transciptomics, proteomics and metabolomics, and summarize the information available in the literature, as it pertains to biomarker identification for BPD. Using "omics" technologies, investigators have reported markers that have the potential to be used as biomarkers of BPD: SPOCK2, VEGF -624C > G, VEGF -460T > C, mast cells specific markers, miR-219 pathway, miR-152, -30a-3p, -133b, -206, -7, lactate, taurine, trimethylamine-N-oxide, gluconate, myoinositol and alterations in surfactant lipid profile.

Absolute nucleated red blood cells counts do not predict the development of bronchopulmonary dysplasia

OBJECTIVE

We tested the hypothesis that infants with bronchopulmonary dysplasia (BPD) have higher absolute nucleated red blood cells (aNRBCs) counts at birth than controls as a proxy measurement of exposure to intrauterine hypoxia.

METHODS

We studied 39 preterm infants with BPD and compared them to 39 pair-matched controls without BPD. Criteria for exclusion in both groups included factors that may influence the aNRBCs at birth.

RESULTS

In logistic regression, when pre-eclampsia, birthweight, gender, antenatal steroid therapy, 1-min Apgar scores, respiratory distress syndrome (RDS) (or surfactant use), intraventricular hemorrhage of grade 3 or more, nosocomial sepsis, patent ductus arteriosus, and aNRBC counts (or lymphocyte counts) were used as independent variables, and BPD as the dependent variable, only RDS (or its proxy measurement of surfactant use) and nosocomial sepsis remained included in the final analysis.

CONCLUSIONS

aNRBC counts and lymphocyte counts do not appear to be elevated in infants that develop BPD, as compared to pair-matched controls without BPD. We speculate that chronic intrauterine hypoxia does not appear to play a major role in the pathogenesis of BPD. In contrast, postnatal events such as RDS and nosocomial sepsis appear to play a determining role in the pathogenesis of BPD.

Role of GDF15 (growth and differentiation factor 15) in pulmonary oxygen toxicity

GDF15 (growth and differentiation factor 15) is a secreted cytokine, a direct target of p53 and plays a role in cell proliferation and apoptosis. It is induced by oxidative stress and has anti-apoptotic effects. The role of GDF15 in hyperoxic lung injury is unknown. We tested the hypothesis that GDF15 will be induced in vitro, in a model of pulmonary oxygen toxicity, and will play a critical role in decreasing cell death and oxidative stress. BEAS-2B (human bronchial epithelial cells) and human pulmonary vascular endothelial cells (HPMEC) were exposed to hyperoxia, and expression of GDF15 and effect of GDF15 disruption on cell viability and oxidative stress was determined. Furthermore, we studied the effect of p53 knockdown on GDF15 expression. In vitro, both BEAS-2B and HPMEC cells showed a significant increase in GDF15 expression upon exposure to hyperoxia. After GDF15 knockdown, there was a significant decrease in cell viability and increase in oxidative stress compared to control cells transfected with siRNA with a scrambled sequence. Knockdown of p53 significantly decreased the induction of GDF15 by hyperoxia. In conclusion, we show that GDF15 has a pro-survival and anti-oxidant role in hyperoxia and that p53 plays a key role in its induction.

A risk factor analysis on disease severity in 47 premature infants with bronchopulmonary dysplasia

Bronchopulmonary Dysplasia (BPD) is a rare chronic lung disease and one of the most difficult complications to treat in premature infants. With the progress at the medical treatment level, an increasing number of BPD premature infants are born, meanwhile, they would be at an increasing risk for numerous complications and rehospitalization because BPD affects many vital organ systems. The pathogenesis of BPD is clearly multifactorial. As the prognosis is closely connected with the severity of BPD, early diagnosis and treatment are of great help to control the development of BPD. This article focuses on risk factors that could influence the severity of BPD in order to provide a reliable basis for early diagnosis, treatment, and better patient assessment.

Death or survival with major morbidity in VLBW infants born at Brazilian neonatal research network centers

OBJECTIVE

To analyze unfavorable outcomes at hospital discharge of preterm infants born at Brazilian public university centers.

METHODS

Prospective cohort of 2646 inborn infants with gestational age 23-33 weeks and birth weight 400-1499 g, without malformations, born at 20 centers in 2012-2013. Unfavorable outcome was defined as in-hospital death or survival at hospital discharge with ≥1 major morbidities: bronchopulmonary dysplasia (BPD) at 36 corrected weeks, intraventricular hemorrhage (IVH) grades 3-4, periventricular leukomalacia (PVL) or surgically treated retinopathy of prematurity (ROP).

RESULTS

Among 2646 infants, 1390 (53%) either died or survived with major morbidities: 793 (30%) died; 497 (19%) had BPD; 358 (13%) had IVH 3-4 or PVL; and 84 (3%) had ROP. Logistic regression adjusted by center showed association of unfavorable outcome with: antenatal steroids (OR 0.70; 95%CI 0.55-0.88), C-section (0.72; 0.58-0.90), gestational age <30 (4.00; 3.16-5.07), being male (1.44; 1.19-1.75), small for gestational age (2.19; 1.72-2.78), 5th-min Apgar <7 (3.89; 2.88-5.26), temperature at NICU admission <36.0 °C (1.42; 1.15-1.76), respiratory distress syndrome (3.87; 2.99-5.01), proven late sepsis (1.33; 1.05-1.69), necrotizing enterocolitis (3.10; 2.09-4.60) and patent ductus arteriosus (1.69; 1.37-2.09).

CONCLUSIONS

More than half of the VLBW infants born at public university level 3 Brazilian hospitals either die or survive with major morbidities.

Preterm cord blood CD4⁺ T cells exhibit increased IL-6 production in chorioamnionitis and decreased CD4⁺ T cells in bronchopulmonary dysplasia

BACKGROUND

Chorioamnionitis (CA) is associated with premature delivery and bronchopulmonary dysplasia (BPD). We hypothesize that preterm infants exposed to CA have reduced suppressive regulatory T cells (Treg) and increased non-regulatory T cell pro-inflammatory cytokines, increasing risk for BPD.

OBJECTIVE

To evaluate cord blood CD4(+) T cell regulatory phenotype and pro-inflammatory cytokine production in CA and BPD groups.

STUDY DESIGN

Cord blood mononuclear cells from infants (GA ⩽32 weeks), with or without placental histological evidence of CA (hChorio), were analyzed by flow cytometry. Clinical information was collected by retrospective chart review. Numbers of putative Treg (CD4(+)FoxP3(+)CD25(+)CD127Dim), CD4(+) non-Tregs, and CD4(+) T cell intracellular cytokine content following in vitro stimulation were compared with CA status and oxygen requirement at 36weeks postmenstrual age.

RESULT

Absolute Treg numbers were not different in CA and non-CA exposed samples. However, the infants who developed BPD had a significant decrease in Treg and non-regulatory T cell numbers. Greater IL-6 production was observed in hCA group.

CONCLUSION

A pro-inflammatory CD4(+) T cell status is noted in CA and BPD but the later disease is also associated with decrease in Tregs, suggesting that the development of BPD is marked by distinct inflammatory changes from those of CA exposed infants.

Less invasive surfactant administration is associated with improved pulmonary outcomes in spontaneously breathing preterm infants

AIM

Providing less invasive surfactant administration (LISA) to spontaneously breathing preterm infants has been reported to reduce mechanical ventilation and bronchopulmonary dysplasia (BPD) in randomised controlled trials. This large cohort study compared these outcome measures between LISA-treated infants and controls.

METHODS

Infants receiving LISA, who were born before 32 gestational weeks and enrolled in the German Neonatal Network, were matched to control infants by gestational age, umbilical cord pH, Apgar-score at 5 min, small for gestational age status, antenatal treatment with steroids, gender and highest supplemental oxygen during the first 12 h of life. Outcome data were compared with chi-square and Mann-Whitney U-tests and adjusted for multiple comparisons.

RESULTS

Between 2009 and 2012, 1103 infants were treated with LISA at 37 centres. LISA infants had lower rates of mechanical ventilation (41% versus 62%, p < 0.001), postnatal dexamethasone treatment (2.5% versus 7%, p < 0.001), BPD (12% versus 18%, p = 0.001) and BPD or death (14% versus 21%, p < 0.001) than the controls.

CONCLUSION

Surfactant treatment of spontaneously breathing infants was associated with lower rates of mechanical ventilation and BPD. Additional large-scale randomised controlled trials are needed to assess the possible long-term benefits of LISA.

Very low birthweight bronchopulmonary dysplasia survivors show no substantial association between lung function and current inflammatory markers

AIM

The role of inflammation in the bronchopulmonary dysplasia (BPD) survivors is indistinct. We evaluated lung function in relation to inflammatory markers in plasma, exhaled breath condensate and exhaled air in school-aged very low birthweight (VLBW) survivors with and without radiographic BPD.

METHODS

Pre- and postbronchodilator impulse oscillometry were performed by 21 six to 14-year-old VLBW children with radiographic BPD, 19 VLBW children without radiographic BPD and 19 age-matched nonasthmatic term controls. Eosinophilic cationic protein, interleukins 6 and 8, adiponectin, adipsin, leptin and resistin in plasma, leukotriene B4 and 8-isoprostane in exhaled breath condensate, and bronchial and alveolar nitric oxide output were measured.

RESULTS

Abnormal lung function was found in 12.5% of the former VLBW children. Airway resistance at 5 Hz was highest in the radiographic BPD, but bronchodilator responses were most prominent in the non-BPD group. Plasma adiponectin had a modest positive correlation with obstruction and with bronchodilator responses, and alveolar nitric oxide and plasma interleukin 6 with bronchodilator responses.

CONCLUSION

Very low birthweight children with radiographic BPD had poorest lung function. The most pronounced bronchodilator responses were found in VLBW children without radiographic BPD. Current detected inflammatory markers had only a minor association with lung function in school-aged BPD survivors.

Neonatal glucocorticoid treatment: long-term effects on the hypothalamus-pituitary-adrenal axis, immune system, and problem behavior in 14-17 year old adolescents

Neonatal glucocorticoid (GC) treatment is used to prevent bronchopulmonary dysplasia (BPD) in prematurely born babies. In the 1990s, treatment regimens with relatively high doses of dexamethasone (DEX) were common. As an alternative, hydrocortisone (HC) was used. Earlier, we compared long-term effects of both GCs in children aged 7-10 and detected adverse effects of neonatal DEX treatment, but not of HC, on a range of outcomes. The aim of the current cohort study was to investigate whether long-term effects of neonatal DEX were maintained and whether effects of HC remained absent at adolescent age (14-17years). We compared 71 DEX-treated and 67 HC-treated adolescents. In addition, 71 adolescents who were not neonatally treated with GCs participated. All were born <32weeks of gestation. DEX-treated girls showed increased adrenocorticotropic hormone (ACTH) and cortisol responses in the Trier Social Stress Test. The cortisol awakening response was lower in HC-treated participants compared to untreated participants. Negative feedback function of the HPA-axis in the dexamethasone suppression test did not differ between groups. In contrast to our observations at the age of 7-10years, we did not observe group differences in mitogen-induced cytokine production at the age of 14-17years. DEX-treated girls showed more social problems and anxious/depressed behavior than HC-treated girls. Untreated girls showed more problem behavior as well. In conclusion, our results suggest that, especially in girls, neonatal DEX has a programming effect on the HPA-axis and on the ability to adjust to the environment. The loss of group differences on immune system measures indicate that potentially negative effects detected at a younger age subsided.

Perinatal conditions related to growth restriction and inflammation are associated with an increased risk of bronchopulmonary dysplasia

AIM

Bronchopulmonary dysplasia (BPD) is a frequent chronic lung disease in preterm infants, and we aimed to identify factors associated with this condition in infants with respiratory distress syndrome (RDS).

METHODS

This case-control study, using national Swedish data, included 2255 preterm infants, born before 33 gestational weeks. The 667 BPD cases were oxygen dependent at 36 weeks' postmenstrual age, and the 1558 controls only had RDS. Comparisons included perinatal conditions and pharmacological treatments. Adjusted odds ratios with 95% confidence intervals were calculated in a conditional logistic regression model, with gestational age as the conditioning term.

RESULTS

An increased risk of BPD was associated with prelabour preterm rupture of membranes of more than 1 week (3.35, 2.16-5.19), small for gestational age (2.73, 2.11-3.55), low Apgar score (1.37, 1.05-1.81), patent ductus arteriosus (1.70, 1.33-2.18), persistent pulmonary hypertension (5.80, 3.21-10.50), pulmonary interstitial emphysema (2.78, 1.37-5.64), pneumothorax (2.95, 1.85-4.72), late onset infections (2.69, 1.82-3.98), intubation (1.56, 1.20-2.03), chest compressions (2.05, 1.15-3.66) and mechanical ventilation (2.16, 1.69-2.77), but not antenatal corticosteroids.

CONCLUSION

Growth restriction and inflammation increased the risk of BPD in preterm infants and prelabour preterm rupture of membranes, small for gestational age, low Apgar score or need for resuscitation should raise clinical suspicions.

Bronchopulmonary dysplasia - an overview about pathophysiologic concepts

Neonatal chronic lung disease in the preterm infant, i.e. bronchopulmonary dysplasia (BPD) is characterized by impaired pulmonary development with its effects persisting into adulthood. Triggered in the immature lung by infectious complications, oxygen toxicity and the impact of mechanical ventilation, a sustained inflammatory response, extensive remodeling of the extracellular matrix, increased apoptosis as well as altered growth factor signaling characterize the disease. The current review focuses on selected pathophysiologic processes and their interplay in disease development. Furthermore, the potential of both, acute and long-term changes to the pulmonary scaffold and the cellular interface in concert with dysregulated growth factor signaling to affect aging and repair processes in the adult lung is discussed.

The Association of Mean Platelet Volume with Intra Ventricular Hemorrhage and Broncho Pulmonary Dysplasia in Preterm Infants

BACKGROUND

Interventricular hemorrhage (IVH) and Broncho pulmonary dysplasia(BPD) commonly occur in premature infants and they associate with platelet dysfunction. The aim of this study was to investigate the association of MPV and occurrence of IVH and BPD.

MATERIALS AND METHODS

In this cross sectional study, 3 groups including IVH, BPD and control were compared. All participants were preterm neonates with <35 weeks of gestation. MPV was recorded during the first 48 hours of life for all cases. Data were reported by descriptive statistics and analyzed by Pearson correlation coefficient, spearman correlation coefficient, paired T test and multinomial regression analysis in SPSS version 17.

RESULTS

Higher MPV level was noted in BPD and IVH groups versus control group (9.79±0.73 fl and 10±1.04 fl versus 8.33±0,91 fl p<0.0001). Also, most participants in BPD (93.3%) and IVH (73.3%) groups had MPV >9 fl compared to controls (16.7%) (p<0.0001). Regression analysis showed that only MPV related to the occurrence of IVH (OR=2.200 95%CI p=0.013) and elevated MPV significantly increased duration of O2 therapy (p<0.0001) and mechanical ventilation (p=0.0010).

CONCLUSION

MPV value at first 48 hours of life can be noted as a simple biomarker for occurrence of BPD and specially IVH in preterm infants.

The Evidence-based Practice for Improving Quality method has greater impact on improvement of outcomes than dissemination of practice change guidelines and quality improvement training in neonatal intensive care units

OBJECTIVES

To determine whether outcome improvements achieved by neonatal intensive care units (NICUs) in the Evidence-based Practice for Improving Quality (EPIQ) trial could be reproduced in other NICUs by providing quality improvement (QI) training and practice change guidelines developed during the EPIQ trial; and to examine whether the results of the EPIQ trial were sustained.

METHODS

The present prospective before-after study included 5812 infants born at ≤32 weeks' gestation and admitted to 19 level 3 NICUs in the Canadian Neonatal Network between October 1, 2005 and December 31, 2007. During a three-month baseline period, multi-disciplinary teams received general training in QI techniques at a two-day workshop, and practice change guidelines targeting nosocomial infection (NI) and bronchopulmonary dysplasia (BPD) developed during the EPIQ trial were provided to all participants. Outcome data collected during the intervention period were compared with data from the baseline period and reported quarterly.

RESULTS

In NICUs that had not previously participated in the EPIQ trial (non-EPIQ NICUs), there were no significant changes in the incidence trends of NI or BPD. However, within NICUs that had previously participated in the EPIQ trial (EPIQ NICUs) there was a continued reduction in the incidence trend of NI and BPD among EPIQ NICUs randomized during the trial to reduce NI and BPD, respectively.

CONCLUSIONS

Providing NICUs with QI training and practice change guidelines developed during a successful QI initiative in other units is not effective. The authors speculate that successful practice change involves organizational culture and behaviour change, and should be driven by context-specific evidence.

Medical closure of patent ductus arteriosus does not reduce mortality and development of bronchopulmonary dysplasia in preterm infants

BACKGROUND

Although, patent ductus arteriosus (PDA) is associated with significant morbidity due to hemodynamic instability in preterm infants, the effect of ductus closure on mortality and morbidity is a controversial issue. The aim is to evaluate the efficacy of oral and intravenous (IV) ibuprofen treatment on ductal closure and effects on mortality and bronchoplumonary dysplasia.

MATERIALS AND METHODS

The medical records of 292 premature infants treated at Ege University Neonatal Intensive Care Unit were retrospectively evaluated. Patients were classified into 3 groups as; No PDA, hemodynamically insignificant PDA (hiPDA) and hemodynamically significant PDA (hsPDA) according to the presence and hemodynamical significance of PDA by echocardiography. hsPDA group was treated with IV or oral ibuprofen.

RESULTS

Patent ductus arteriosus was diagnosed by routine echocardiography in 145 patients, of whom 78 (53.7%) had hsPDA. All 65 infants with hiPDA had spontaneous PDA closure. Echocardiographic measurements were similar to those patients treated with oral or IV ibuprofen, as in the response rate to treatment without serious adverse effects. The presence of respiratory distress syndrome, surfactant therapy, late sepsis, bronchopulmonary dysplasia (BPD) and mortality rates were significantly higher in patients with hsPDA. However, with stepwise logistic regression; 5(th) min Apgar score (odds ratio [OR], 1.321, 95% confidence interval [CI], 1.063-1.641, P = 0.012) and gestational age (OR, 1.422, 95% CI, 1.212-1.662, P < 0.001) were the only significant variables associated with mortality. Gestational age (OR, 0.680, 95% CI, 0.531-0.871, P = 0.002) was the only significant variable associated with BPD shown with logistic regression.

CONCLUSION

Ibuprofen treatment is effective for hsPDA closure with minimal side effects. HiPDA can close spontaneously; therefore treatment decision should be individualized. However, medical treatment of PDA does not reduce mortality and BPD.

Neonatal ventilation strategies and long-term respiratory outcomes

Long-term respiratory morbidity is common, particularly in those born very prematurely and who have developed bronchopulmonary dysplasia (BPD), but it does occur in those without BPD and in infants born at term. A variety of neonatal strategies have been developed, all with short-term advantages, but meta-analyses of randomized controlled trials (RCTs) have demonstrated that only volume-targeted ventilation and prophylactic high-frequency oscillatory ventilation (HFOV) may reduce BPD. Few RCTs have incorporated long-term follow-up, but one has demonstrated that prophylactic HFOV improves respiratory and functional outcomes at school age, despite not reducing BPD. Results from other neonatal interventions have demonstrated that any impact on BPD may not translate into changes in long-term outcomes. All future neonatal ventilation RCTs should have long-term outcomes rather than BPD as their primary outcome if they are to impact on clinical practice.

The role of Mycoplasma and Ureaplasma in adverse pregnancy outcomes

Genital mycoplasmas are frequently found in the vaginal flora across socioeconomic and ethnic groups and have been demonstrated to be involved in adverse perinatal outcomes. Both Mycoplasma and Ureaplasma spp cause inflammation potentially leading to spontaneous preterm birth and PPROM as well as postdelivery infectious complications and neonatal infections. Herein we have provided an overview of the existing literature and supportive evidence for genital mycoplasma's role in perinatal complications. Future research will need to focus on clearly delineating the species, allowing for discrimination of their effects.

L-citrulline provides a novel strategy for treating chronic pulmonary hypertension in newborn infants

Effective therapies are urgently needed for infants with forms of pulmonary hypertension that develop or persist beyond the first week of life. The L-arginine nitric oxide (NO) precursor, L-citrulline, improves NO signalling and ameliorates pulmonary hypertension in newborn animals. In vitro studies demonstrate that manipulating L-citrulline transport alters NO production.

CONCLUSION

Strategies that increase the supply and transport of L-citrulline merit pursuit as novel approaches to managing infants with chronic, progressive pulmonary hypertension.

Differential concentration-specific effects of caffeine on cell viability, oxidative stress, and cell cycle in pulmonary oxygen toxicity in vitro

Caffeine is used to prevent bronchopulmonary dysplasia (BPD) in premature neonates. Hyperoxia contributes to the development of BPD, inhibits cell proliferation and decreases cell survival. The mechanisms responsible for the protective effect of caffeine in pulmonary oxygen toxicity remain largely unknown. A549 and MLE 12 pulmonary epithelial cells were exposed to hyperoxia or maintained in room air, in the presence of different concentrations (0, 0.05, 0.1 and 1mM) of caffeine. Caffeine had a differential concentration-specific effect on cell cycle progression, oxidative stress and viability, with 1mM concentration being deleterious and 0.05 mM being protective. Reactive oxygen species (ROS) generation during hyperoxia was modulated by caffeine in a similar concentration-specific manner. Caffeine at 1mM, but not at the 0.05 mM concentration decreased the G2 arrest in these cells. Taken together this study shows the novel funding that caffeine has a concentration-specific effect on cell cycle regulation, ROS generation, and cell survival in hyperoxic conditions.

Oxidative stress and bronchopulmonary dysplasia

Bronchopulmonary dysplasia (BPD) is the major cause of pulmonary disease in infants. The pathophysiology and management of BPD changed with the improvement of neonatal intensive care unit (NICU) management and with the increase of survival rates. Despite the improvements made, BPD is still a public health concern, resulting in frequent hospitalizations with high rates of mortality, impaired weight and height growth, and neurodevelopmental disorders. Lung injury in the neonatal period has multiple etiologic factors - genetic, hemodynamic, metabolic, nutritional, mechanical, and infectious mechanisms - act in a cumulative and synergic way. Free radical (FR) generation is largely recognized as the major cause of lung damage. Oxidative stress (OS) is the final common endpoint for a complex convergence of events, some genetically determined and some triggered by in utero stressors. Inflammatory placental disorders and chorioamnionitis also play an important role due to the coexistence of inflammatory and oxidative lesions. In addition, the contribution of airway inflammation has been extensively studied. The link between inflammation and OS injury involves the direct activation of inflammatory cells, especially granulocytes, which potentiates the inflammatory reaction. Individualized interventions to support ventilation, minimize oxygen exposure, minimize apnea, and encourage growth should decrease both the frequency and severity of BPD. Future perspectives suggest supplementation with enzymatic and/or non-enzymatic antioxidants. The use of antioxidants in preterm newborns particularly exposed to OS and at risk for BPD represents a logical strategy to ameliorate FRs injury, but further studies are needed to support this hypothesis.

Stem cell therapy for neonatal diseases associated with preterm birth

In the last decades, the prevention and treatment of neonatal respiratory distress syndrome with antenatal steroids and surfactant replacement allowed the survival of infants born at extremely low gestational ages. These extremely preterm infants are highly vulnerable to the detrimental effects of oxidative stress and infection, and are prone to develop lung and brain diseases that eventually evolve in severe sequelae: The so-called new bronchopulmonary dysplasia (BPD) and the noncystic, diffuse form of periventricular leukomalacia (PVL). Tissue simplification and developmental arrest (larger and fewer alveoli and hypomyelination in the lungs and brain, respectively) appears to be the hallmark of these emerging sequelae, while fibrosis is usually mild and contributes to a lesser extent to their pathogenesis. New data suggest that loss of stem/progenitor cell populations in the developing brain and lungs may underlie tissue simplification. These observations constitute the basis for the application of stem cell-based protocols following extremely preterm birth. Transplantation of different cell types (including, but not limited to, mesenchymal stromal cells, endothelial progenitor cells, human amnion epithelial cells) could be beneficial in preterm infants for the prevention and/or treatment of BPD, PVL and other major sequelae of prematurity. However, before this new knowledge can be translated into clinical practice, several issues still need to be addressed in preclinical in vitro and in vivo models.

Oxygen therapy in preterm infants

Despite being the most widely used and vital therapy in neonatology, optimal strategies for the use of oxygen in preterm infants remain controversial. Achieving the balance between attaining adequate tissue oxygenation and avoiding oxygen toxicity is challenging. There remains a paucity of clear evidence based guidance for clinicians on safe oxygen saturation targets. What does seem apparent is that these targets vary over time in the life of a preterm infant. This article summarises the evidence behind current practice of oxygen monitoring and administration from the first few minutes after birth, through to the acute neonatal and later convalescent periods. Finally, we review the use of home oxygen for preterm infants with bronchopulmonary dysplasia including administration and weaning from domically home oxygen.

Placental pathologic changes of maternal vascular underperfusion in bronchopulmonary dysplasia and pulmonary hypertension

INTRODUCTION

Bronchopulmonary dysplasia (BPD) is the most common chronic lung disease of infancy, and BPD-associated pulmonary hypertension (PH) is a serious complication that can negatively impact later childhood health. There is growing evidence that lung injury leading to BPD and PH is due to chronic fetal hypoxia-ischemia. The purpose of this study was to investigate whether placental pathologic changes of maternal vascular underperfusion (MVU) are associated with BPD, and further increased with PH.

METHODS

We conducted a 5-year retrospective cohort study of premature infants born ≤28 weeks. BPD was defined as persistent oxygen requirement at 36 weeks corrected gestational age. PH was identified using a standardized algorithm of echocardiogram review. Archived placental slides underwent standardized masked histopathologic review. Logistic regression modeling was performed, taking into account important maternal and infant covariates.

RESULTS

Among 283 births, 121 had MVU, of which 67 (55%) developed BPD, and 24 (20%) had PH. Among the common neonatal complications of extreme prematurity, BPD was the only outcome that was increased with MVU (P < 0.001). After adjustment for birth weight, fetal growth restriction, preeclampsia and other factors, infants with MVU were more likely to develop BPD (adjusted odds ratio = 2.6; 95% confidence interval = 1.4, 4.8). Certain MVU sublesions (fibrinoid necrosis/acute atherosis and distal villous hypoplasia/small terminal villi) were increased with PH (P < 0.001).

DISCUSSION

Placental MVU may identify BPD infants who were exposed to intrauterine hypoxia-ischemia, which increases their risk for development of PH disease.

CONCLUSIONS

Our findings have important implications for providing earlier and more effective therapies for BPD.

Ascorbylperoxide from parenteral nutrition induces an increase of redox potential of glutathione and loss of alveoli in newborn guinea pig lungs

Background

Bronchopulmonary dysplasia is one of the main complications associated with extreme prematurity. Oxidative stress is suspected to be a trigger event of this lung disease, which is characterized by impaired alveolar development. Peroxides, mainly ascorbylperoxide and H₂O₂, are known contaminant of parenteral nutrition. We hypothesize that these oxidant molecules induce bronchopulmonary dysplasia development. The aim was to determine if the infusion of ascorbylperoxide, whether in presence or absence of H₂O₂, is associated with oxidative stress, apoptosis and loss of alveoli in the lungs of newborn guinea pigs.

Method

Three-day-old guinea pigs received parenteral solutions containing 0, 20, 60 or 180 µM ascorbylperoxide in the presence or not of 350 µM H₂O₂ (concentrations similar to those measured in parenteral nutrition). After 4 days, the lungs were collected for determination of glutathione's redox potential, caspase-3 activation (an apoptosis marker), alveolarization index (by histology), activation of Nrf2 and NF?B (biological markers of oxidative stress), and IL-6 and PGJ₂ levels (markers of NF?B activation). Groups were compared by ANOVA, p < 0.05.

Results

Loss of alveoli was associated with ascorbylperoxide in a dose-dependent manner, without an influence of H₂O₂. The dose-dependent activation of caspase-3 by ascorbylperoxide was lower in the presence of H₂O₂. Ascorbylperoxide induced an increase of redox potential in a dose-dependent manner, which reached a plateau in presence of H₂O₂. Nrf2 and NF?B were activated by H₂O₂ but not by ascorbylperoxide.

Conclusion

Results suggest that ascorbylperoxide, generated in parenteral nutrition, is involved in the development of bronchopulmonary dysplasia, independently of the increase of the redox potential. This study underlines the importance of developing a safer formulation of parenteral nutrition.

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Oxidative stress is suspected to induce bronchopulmonary dysplasia.

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We investigate the role of ascorbylperoxide contaminating parenteral nutrition.

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This molecule induces oxidation of redox potential, apoptosis and loss of alveoli.

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The alveolar loss is independent of the redox potential.

Functional outcome at school age of preterm-born children treated with high-dose dexamethasone

BACKGROUND

Postnatal dexamethasone (DXM) treatment is associated with adverse motor outcome. It is largely unknown as to what extent functional outcome at school age is affected.

AIMS

Our first aim was to determine motor, cognitive, and behavioural outcome at school age of preterm-born children treated with high-dose DXM for pulmonary problems. Our second aim was to identify DXM-related risk factors for adverse outcome.

STUDY DESIGN

In this cohort study, we included 53 very preterm-born children treated with DXM (starting dose 0.5mg/kg/d) after the first week of life. At the median age of 9 years, we performed a detailed neuropsychological assessment.

RESULTS

Compared to the norm population, DXM-treated children scored worse on the Movement-ABC (abnormal fine motor, ball skills and balance: 59%, 47% and 30%, respectively). They more often had total (36%), verbal (32%) and performance IQs (55%) below 85 (P<.001, P=.002, P<.001, respectively). On each of the remaining measures, DXM-treated children scored worse than the norm population, except for verbal long-term memory and verbal recognition memory. DXM-related risk factors were associated with poorer performance.

CONCLUSIONS

At school age, multiple domains of functional outcome were affected in DXM-treated children. Risk factors related to the use of DXM should be considered as serious potentiaters of adverse outcome in children treated with high-dose DXM.

The relationship between eosinophilia and bronchopulmonary dysplasia in premature infants at less than 34 weeks' gestation

Purpose

Eosinophilia is common in premature infants, and its incidence increases with a shorter gestation period. We investigated the clinical significance of eosinophilia in premature infants born at <34 weeks gestation.

Methods

We analyzed the medical records of premature infants born at <34 weeks gestation who were admitted to the neonatal intensive care unit at Ewha Womans University Mokdong Hospital between January 2003 and September 2010. Eosinophilia was defined as an eosinophil percentage of >3% of the total leukocytes. Perinatal parameters and clinical parameters were also analyzed.

Results

Of the 261 infants born at <34 weeks gestation, 22.4% demonstrated eosinophilia at birth. The eosinophil percentage peaked in the fourth postnatal week at 7.5%. The incidence of severe eosinophilia increased after birth up to the fourth postnatal week when 8.8% of all patients had severe eosinophilia. Severity of eosinophilia was positively correlated with a lower gestational age, birth weight, and Apgar score. Respiratory distress syndrome, bronchopulmonary dysplasia, nephrocalcinosis, intraventricular hemorrhage, and sepsis were associated with a higher eosinophil percentage. The eosinophil percentage was significantly higher in infants with bronchopulmonary dysplasia from the first postnatal week and the percentage was the highest in the fourth postnatal week, with the maximal difference being 4.1% (P<0.001).

Conclusion

Eosinophilia is common in premature infants and reaches peak incidence and severity in the fourth postnatal week. The eosinophil percentage was significantly higher in bronchopulmonary dysplasia patients from the first postnatal week. Severe eosinophilia was significantly associated with the incidence of bronchopulmonary dysplasia even after adjusting for other variables.

Outcomes of tracheostomy in the neonatal intensive care unit: is there an optimal time?

OBJECTIVE

To compare short-term outcomes of infants who underwent early versus late tracheostomy during their initial hospitalization after birth and determine the association, if any, between tracheostomy timing and outcomes.

STUDY DESIGN

Retrospective chart review of infants who underwent a tracheostomy during their initial hospitalization at a single site.

RESULTS

The median (range) gestational age of our cohort (n = 127) was 28 (23-42) weeks and birth weight was 988 (390-4030) g. Tracheostomy indications included airway lesions (47%), bronchopulmonary dysplasia (25%), both (22%) and others (6%). Median postmenstrual age (PMA) at tracheostomy was 45 (35-75) weeks. Death occurred in 27 (21%) infants and 65 (51%) infants were mechanically ventilated. G-tube was present at discharge in 42 (33%) infants. Infants who underwent early tracheostomy (<45 weeks PMA) (n = 66) had significantly lower gestational ages, weights and respiratory support than the late (≥45 weeks PMA) (n = 61) group. Death (29.5% versus 14%), home ventilation (41% versus 21%) and G tube (44% versus 14%) were significantly more frequent in the late tracheostomy group. On bivariate regression, outcomes were not independently associated with tracheostomy timing, after adjustment for gestational age and respiratory support.

CONCLUSIONS

Of infants who underwent tracheostomy during the initial hospitalization after birth, 21% died. On adjusted analysis, tracheostomy timing was not independently associated with outcomes.

Respiratory outcomes for the tiniest or most immature infants

Extremely low birth weight (<1000 g birth weight) or extremely preterm (<28 weeks of gestation) infants are surviving in greater numbers as neonatal care advances. Many of these survivors, especially those who develop bronchopulmonary dysplasia, have more respiratory ill health in the first years after discharge home, reduced respiratory function and impaired exercise capacity throughout childhood and into adulthood compared with term-born controls. It is important to establish the long-term respiratory outcomes for the tiniest or most immature survivors as they grow older, since they may contribute disproportionately to rates of chronic obstructive pulmonary disease and respiratory ill-health in adulthood.

Ureaplasma and bronchopulmonary dysplasia

Advances in neonatal intensive care have greatly improved survival rates for children born in a very early stage of lung development (i.e. less than 26 weeks of gestation). In these premature babies, even low levels of oxygen and methods of minimally invasive ventilation may disrupt the growth of the distal airways, a condition described as "new" bronchopulmonary dysplasia (BPD). Ureaplasma infection can occur in utero or in the perinatal period in premature infants, in some of which the infection with these organisms triggers an important lung pro-inflammatory and pro-fibrotic response, and may increase the risk of developing BPD. The inflammation may be worsened by exposure to oxygen and mechanical ventilation. At present, clinical studies have not clarified the role of Ureaplasma in the pathogenesis of BPD and there is insufficient evidence to determine whether antibiotic treatment of Ureaplasma has influence on the development of BPD and its comorbidities. Future research in the context of well-designed and controlled clinical trials of adequate statistical power should focus on how to determine whether the treatment of Ureaplasma decreases lung inflammation, reduces rates of BPD, and improves long-term neurodevelopment.

That chorioamnionitis is a risk factor for bronchopulmonary dysplasia--the case against

Bronchopulmonary dysplasia (BPD) is the most frequent long term sequelae in infants born at less than 29 weeks of gestational age (GA) and histological chorioamnionitis (CA) is the most frequent condition associated with very preterm birth. Numerous studies have explored the association between BPD and CA with conflicting results. This inconsistency may be attributable to differences in populations, definitions, methods, and whether potential confounding factors such as GA, antenatal steroids, and post natal events were considered. A recent systematic review and meta-analysis shows some evidence of an association between BPD and CA; however, results adjusting for important confounders show more conservative measures of association. In addition, there was evidence of publication bias: when controlling for publication bias the results were more conservative and adjusted results were no longer significant. Recent large cohort studies not included in the systematic review do not support the belief that CA is associated with an increased risk of BPD. Despite a large body of evidence, CA cannot be definitively considered a risk factor for BPD.

Management during the first 72 h of age of the periviable infant: an evidence-based review

After NICU admission the extremely immature newborn (EIN) requires evaluation and support of each organ system, and the integration of all those supports in a comprehensive plan of care. In this review, I attempt to analyze the evidence for treatment options after the initial transition, during the first 3 days of life, which have been shown to improve survival or short- or long-term morbidity. This review revealed several things: there is little available evidence from studies that have included significant numbers of EINs; interventions affecting different organ systems need to be co-ordinated as any intervention will have multiple effects; and future advances in treatment of this group of patients will require the installation of permanent research networks to have enough power to perform many studies needed to improve outcomes.

Brain magnetic resonance imaging in infants with surgical necrotizing enterocolitis or spontaneous intestinal perforation versus medical necrotizing enterocolitis

Magnetic resonance imaging of the brain was performed in 26 preterm infants with necrotizing enterocolitis (NEC) or spontaneous intestinal perforation at term equivalent age. Infants with surgical NEC or spontaneous intestinal perforation had significantly more brain injury on magnetic resonance imaging compared with infants with medical NEC, even after adjustment for confounders.

Volumetric capnography in infants with bronchopulmonary dysplasia

OBJECTIVES

To assess the feasibility of using volumetric capnography in spontaneously breathing small infants and its ability to discriminate between infants with and without bronchopulmonary dysplasia (BPD).

STUDY DESIGN

Lung function variables for 231 infants (102 term, 52 healthy preterm, 77 BPD), matched for post-conceptional age of 44 weeks, were collected. BPD was defined as supplemental oxygen requirement at 36 weeks post-menstrual age. Tidal breath-by-breath volume capnograms were obtained by mainstream capnography. The capnographic slope of phase II (SII) and slope of phase III (SIII) were calculated and compared between study groups. The effect of BPD, tidal volume (VT), respiratory rate (RR), and prematurity on the magnitude of the slopes was assessed.

RESULTS

SII was steeper in infants with BPD (100 ± 28/L) compared with healthy preterm (88 ± 22/L; P = .007) and term infants (79 ± 18/L; P < .001), but this finding was attributed to differences in VT, RR, and gestational age. SIII was steeper in the BPD group (26.8 ± 14.1/L) compared with healthy preterm (16.2 ± 6.2/L; P < .001) and term controls (14.8 ± 5.4/L; P < .001). BPD was a significant predictor of SIII independently of VT, RR, and gestational age. The ability of SIII to discriminate between BPD and controls was significantly higher compared with lung clearance index (area under the curve 0.83 vs 0.56; P < .001).

CONCLUSIONS

Volumetric capnography may provide valuable information regarding functional lung alterations related to BPD and might be considered as an alternative to more involved lung function techniques for monitoring chronic lung disease during early infancy.

Ongoing issues in the intensive care for the periviable infant--nutritional management and prevention of bronchopulmonary dysplasia and nosocomial infections

The focus of this paper is to describe the following: (1) the benefits of implementing feeding guidelines, (2) management practices associated with the prevention of BPD, and (3) management practices associated with prevention of nosocomial infection.

Bronchopulmonary dysplasia - trends over three decades

OBJECTIVES

To describe the characteristics of bronchopulmonary dysplasia (BPD) and respiratory distress syndrome subjects, along with the trends in severity and mortality associated with BPD over the past three decades.

METHODS

Retrospective study of BPD and respiratory distress syndrome subjects born between 1980 and 2008, and admitted to Montreal Children's Hospital (Montreal, Quebec). Data were abstracted from hospital records.

RESULTS

Gestational age and birth weight were correlated with the occurrence of BPD with each additional week of gestation and 100 g in birth weight being associated with an OR of developing BPD of 0.77 and 0.89, respectively. BPD severity was associated with male sex, Apgar score and the occurrence of neonatal pneumonia. Significant trends were observed for lower mortality despite lower gestational age and birth weight, greater maternal age and multiple gestations.

CONCLUSION

Mortality from BPD has improved over the past three decades despite significant trends toward more pronounced prematurity and lower birth weights.

Pulmonary outcome in former preterm, very low birth weight children with bronchopulmonary dysplasia: a case-control follow-up at school age

OBJECTIVE

To assess and compare long-term pulmonary outcomes in former preterm-born, very low birth weight (VLBW) children with and without bronchopulmonary dysplasia (BPD) born in the surfactant era.

STUDY DESIGN

Pulmonary function tests (ie, spirometry, body plethysmography, and gas transfer testing) were performed in children with a history of VLBW and BPD (n = 28) and compared with a matched preterm-born VLBW control group (n = 28). Medical history was evaluated by questionnaire.

RESULTS

At time of follow-up (mean age, 9.5 years), respiratory symptoms (36% vs 8%) and receipt of asthma medication (21% vs 0%) were significantly more frequent in the preterm-born children with previous BPD than in those with no history of BPD. The children with a history of BPD had significantly lower values for forced expiratory volume in 1 second (z-score -1.27 vs -0.4; P = .008), forced vital capacity (z-score -1.39 vs -0.71 z-score; P = .022), and forced expiratory flow rate at 50% of forced vital capacity (z-score -2.21 vs -1.04; P = .048) compared with the preterm control group.

CONCLUSION

Preterm-born children with a history of BPD are significantly more likely to have lung function abnormalities, such as airway obstruction and respiratory symptoms, at school age compared with preterm-born children without BPD.

Sleep quality, stress, caregiver burden, and quality of life in maternal caregivers of young children with bronchopulmonary dysplasia

Little is known about the influence of sleep quality, stress, and caregiver burden on quality of life in maternal caregivers of young children with bronchopulmonary dysplasia (BPD). In 61 maternal caregivers (mean age 29.59 years) of young children with BPD (mean age 13.93 months), caregivers reported sleeping a mean of 5.8 hours, and significant correlations were found between sleep quality and depressive symptoms and stress, as well as an inverse correlation with quality of life. Sleep quality was found to be the most significant predictor of quality of life in maternal caregivers.

A randomized controlled trial of two nasal continuous positive airway pressure levels after extubation in preterm infants

OBJECTIVE

To compare extubation failure rate with two ranges of nasal continuous positive airway pressure (NCPAP) in oxygen dependent preterm infants.

STUDY DESIGN

Preterm infants of birth weight 500-1000 g and gestational age 23-30 weeks, extubated for the first time during the first 6 weeks while requiring fraction of inspired oxygen ≥ 0.25, were randomly assigned to a NCPAP range of 4-6 (low NCPAP) or 7-9 (high NCPAP) cmH2O.

RESULTS

Infants were randomized to low (n = 47) or high NCPAP (n = 46) at day 16.3 ± 14.7 and 15.5 ± 12.4, respectively. Rates of extubation failure per criteria (24% vs 43%, P = .04, OR and 95% CI: 0.39 [0.16-0.96]) and re-intubation (17% vs 38%, P = .023, 0.33 [0.016-0.85]) within 96 hours were significantly lower in the high- compared with the low NCPAP group. This was mainly due to a strikingly lower failure rate in the 500-750 g birth weight strata. Duration of ventilation, bronchopulmonary dysplasia, or severe bronchopulmonary dysplasia did not differ significantly. No infant developed pneumothorax during 96 hours post-extubation.

CONCLUSIONS

Extubation failure in preterm infants with residual lung disease was lower with NCPAP range of 7-9 compared with 4-6 cmH2O. These findings suggest the need for higher distending pressure post-extubation in the more immature infants who are still oxygen dependent.

Rosiglitazone, a peroxisome proliferator-activated receptor-γ agonist, restores alveolar and pulmonary vascular development in a rat model of bronchopulmonary dysplasia

PURPOSE

We tested whether rosiglitazone (RGZ), a peroxisome proliferator-activated receptor-γ agonist, can restore alveolar development and vascular growth in a rat model of bronchopulmonary dysplasia (BPD).

MATERIALS AND METHODS

A rat model of BPD was induced through intra-amniotic delivery of lipopolysaccharide (LPS) and postnatal hyperoxia (80% for 7 days). RGZ (3 mg/kg/d, i.p.) or vehicle was given daily to rat pups for 14 days. This model included four experimental groups: No BPD+vehicle (V), No BPD+RGZ, BPD+V, and BPD+RGZ. On D14, alveolarization, lung vascular density, and right ventricular hypertrophy (RVH) were evaluated.

RESULTS

Morphometric analysis revealed that the BPD+RGZ group had significantly smaller and more complex airspaces and larger alveolar surface area than the BPD+V group. The BPD+RGZ group had significantly greater pulmonary vascular density than the BPD+V group. Western blot analysis revealed that significantly decreased levels of vascular endothelial growth factor (VEGF) and its receptor VEGFR-2 by the combined exposure to intra-amniotic LPS and postnatal hyperoxia were restored by the RGZ treatment. RVH was significantly lesser in the BPD+RGZ group than in the BPD+V group.

CONCLUSION

These results suggest that RGZ can restore alveolar and pulmonary vascular development and lessen pulmonary hypertension in a rat model of BPD.

Concurrent bloodstream infections in infants with necrotizing enterocolitis

OBJECTIVE

To determine the incidence, microbiology, risk factors, and outcomes related to bloodstream infections (BSIs) concurrent with the onset of necrotizing enterocolitis (NEC).

STUDY DESIGN

We performed a retrospective review of all cases of NEC in a single center over 20 years. BSI was categorized as "NEC-associated" if it occurred within 72 hours of the diagnosis of NEC and "post-NEC" if it occurred >72 hours afterwards. Demographics, hospital course data, microbiologic data, and outcomes were compared via univariate and multivariate analyses.

RESULTS

NEC occurred in 410 infants with mean gestational age and birth weight of 29 weeks and 1290 g, respectively; 158 infants were diagnosed with at least one BSI; 69 (43.7%) with NEC-associated BSI, and 89 (56.3%) with post-NEC BSI. Two-thirds of NEC-associated BSI were due to gram-negative bacilli compared with 31.9% of post-NEC BSI (OR: 4.27; 95% CI: 2.02, 9.03) and 28.5% of all BSI in infants without NEC (OR: 5.02; 95% CI: 2.82, 8.96). Infants with NEC-associated BSI had higher odds of requiring surgical intervention (aOR: 3.51; 95% CI: 1.98, 6.24) and death (aOR: 2.88; 95% CI: 1.39, 5.97) compared with those without BSI.

CONCLUSIONS

BSI is a common, underappreciated complication of NEC occurring concurrent with the onset of disease and afterwards. The microbiologic etiology of NEC-associated BSI is different from post-NEC and late-onset BSI in infants without NEC with a predominance of gram-negative bacilli. Infants with NEC-associated BSI are significantly more likely to die than those with post-NEC BSI and NEC without BSI.

Postnatal corticosteroids to treat or prevent chronic lung disease in preterm infants

Postnatal corticosteroids have been used for prevention and treatment of neonatal chronic lung disease (CLD) (also know as bronchopulmonary dysplasia), a significant cause of mortality and morbidity in preterm infants. As both dexamethasone and hydrocortisone administration within the first seven days of life is associated with an increased risk of cerebral palsy, early postnatal corticosteroid therapy is not recommended to prevent CLD. After seven days of life, dexamethasone has been shown to decrease the rate of CLD at 36 weeks' postmenstrual age with less impact on neurodevelopmental outcome. No trials have examined whether the benefits of corticosteroids outweigh the adverse effects for infants at high risk of, or with, severe CLD. While routine dexamethasone therapy of all ventilated infants is not recommended, clinicians may consider a short course of low-dose dexamethasone for individual infants at high risk of or with severe CLD. There is no evidence that hydrocortisone is an effective or safe alternative to dexamethasone and little evidence to support routine use of inhaled corticosteroids for prevention or treatment. Inhaled corticosteroids may be considered as an alternative to dexamethasone for treating individual infants with severe CLD. This revision replaces a statement published jointly with the American Academy of Pediatrics in 2002.

Long term cardiovascular consequences of chronic lung disease of prematurity

Pulmonary arterial (PA) hypertension in preterm infant is an important consequence of chronic lung disease of prematurity (CLD) arising mainly due to impaired alveolar development and dysregulated angiogenesis of the pulmonary circulation. Although PA pressure and resistance in these children normalise by school age, their pulmonary vasculature remains hyper-reactive to hypoxia until early childhood. Furthermore, there is evidence that systemic blood pressure in preterm born children with or without CLD is mildly increased at school age and in young adulthood when compared to term-born children. Arterial stiffness may be increased in CLD survivors due to increased smooth muscle tone of the pre-resistance and resistance vessels rather than the loss of elasticity in the large arteries. This review explores the long term effects of CLD on the pulmonary and systemic circulations along with their clinical correlates and therapeutic approaches.

Serological investigation of Ureaplasma urealyticum in Korean preterm infants

Purpose

Ureaplasma colonization is related with perinatal complications in preterm infants. Little is known about the difference in virulence among various Ureaplasma urealyticum serovars. The aim of this study was to determine U. urealyticum serovars of preterm infants in order to assess whether any of the serovars were associated with bronchopulmonary dysplasia (BPD).

Methods

Three hundred forty-four preterm infants with a gestational age less than 34 weeks admitted to Gangnam Severance Hospital neonatal intensive care unit from July 2011 to December 2012 were included in this study. Tracheal and gastric aspirations were conducted on infants to confirm Ureaplasma colonization. Ureaplasma colonization was confirmed in 9% of infants, of these, serovars were determined by real-time polymerase chain reaction.

Results

A total of 31 infants (gestational age, 29.3±3.1 weeks; birth weight, 1,170±790 g) were U. urealyticum positive. The Ureaplasma positive group treated for more days with oxygen and ventilation than the negative group (P<0.05). Histologic chorioamnionitis and moderate to severe BPD were more frequent in the Ureaplasma positive group than in the negative group (P<0.05). U. urealyticum isolates were either found to be a mixture of multiple serovars (32%), serovar 9 alone or combined with other serovars (39%), serovar 11 (26%), 2 (13%), 8 (10%), 10 (13%), and 13 (25%). No individual serovars were significantly associated with moderate to severe BPD and chorioamnionitis.

Conclusion

This is the first study to describe the distribution of U. urealyticum serovars from Korean preterm infants. Ureaplasma-colonized infants showed higher incidence of BPD and chorioamnionitis.

A case report

KEY CLINICAL MESSAGE

A preterm infant at the age of 9 months with severe bronchopulmonary dysplasia (BPD) and large lobar emphysema, compromising ventilation into adjacent lobes with respiratory failure under maximal conservative treatment and pulmonary arterial hypertension recovered initially well after bilateral lung volume reduction surgery, but progressed 2 years later into respiratory failure. The initial imaging with Magnetic-Resonance-Imaging (MRI)-Angiography and decision-making was difficult and interdisciplinary treatment was essential.

Glutathion-S-Transferase P1 polymorphisms association with broncopulmonary dysplasia in preterm infants

BACKGROUND

Oxidative stress, characterized by the excretion of pre-oxidative and anti-oxidative proteases, has a key role in the pathogenesis of bronchopulmonary dysplasia (BPD). One of the many host anti-oxidant enzymes is glutathione-S-transferase P1 (GSTP1), with three polymorphic alleles having been identified: homozygous ile, heterozygous ile/val and homozygous val isomorph. The aim of this study was to examine the genetic predisposition to BPD in the GSTP1 polymorphisms.

METHODS

A prospective case-control study was carried out in the 2nd Neonatal Intensive Care Unit of Aristotle University in Thessaloniki, Greece during 2008. The genetic polymorphisms of GSTP1 in 28 preterms <32 weeks gestational age (GA) with BPD compared to 74 controls (33 preterms without BPD and 41 healthy terms) were examined.

RESULTS

The homozygous ile isomorph was predominant in all groups (preterms with BPD: 82%, preterms without BPD: 70%, healthy terms: 78%), followed by the heterozygous ile/val (14%, 18% and 20% respectively) and the homozygous val isomorph (4%, 12% and 2% respectively). The homozygous ile isomorph was also identified in the majority of preterms with mild (80%), moderate (100%) and severe (73%) BPD. The GSTP1 genetic distribution did not differ between the groups and GSTP1 polymorphisms were not associated with the severity of BPD.

CONCLUSIONS

This study could not confirm an association between GSTP1 polymorphisms and the development of BPD or the severity of the disease.