Changes in Patent Ductus Arteriosus Treatment Strategy and Respiratory Outcomes in Premature Infants.

OBJECTIVE: To evaluate whether change in patent ductus arteriosus (PDA) management strategies over time had an impact on respiratory outcomes in premature infants. STUDY DESIGN: Prospectively collected data were included from all preterm infants born at 23-30 weeks gestational age with PDA admitted to the Children's Hospital of the University of Miami/Jackson Memorial Medical Center from January 1, 2005 to December 31, 2007 (epoch 1) and January 1, 2011 to December 31, 2015 (epoch 2). The 2 epochs were compared for approach with PDA diagnosis and subsequent management strategies and respiratory outcomes. RESULTS: Significantly fewer infants were treated for PDA in epoch 2 (54%) compared with epoch 1 (90%). Multivariable logistic regression analysis demonstrated that infants in epoch 2, with later PDA diagnosis and less frequent PDA treatment, had greater odds of bronchopulmonary dysplasia (BPD), composite of BPD or death, and more treatment with postnatal steroids than in epoch 1. CONCLUSIONS: The change in approach to diagnosis and management of PDA, from a more proactive and aggressive approach during the earlier epoch 1 to a more expectant approach during the subsequent epoch 2, was associated with worse respiratory outcomes, including increase in BPD and in BPD or death.

Lack of response to treatment with levetiracetam in extreme preterm infants with seizures.

OBJECTIVE: The aim of this study was to evaluate the effectiveness of monotherapy with levetiracetam (LEV) in achieving seizure cessation in a retrospective cohort of extreme preterm infants with seizures. STUDY DESIGN: Charts of infants with a diagnosis of neonatal seizures admitted to the NICU between 2013 and 2017 were reviewed. Seizures were diagnosed using continuous video electroencephalography. All infants were initially started on LEV and reached a dose of 80 mg/kg/day. Other ASMs were added to LEV if seizures continued after 2 days. Data on additional clinical variables were collected for each infant. RESULT: Sixty-one infants born <28 weeks of gestation met inclusion criteria. Seventy-four percent of patients did not respond to LEV monotherapy and required additional medications. CONCLUSIONS: LEV monotherapy stopped seizures in only a small portion of cases.

Pentoxifylline and prevention of hyperoxia-induced lung -injury in neonatal rats.

INTRODUCTION: Oxygen exposure plays an important role in the pathogenesis of bronchopulmonary dysplasia (BPD). The phosphodiesterase inhibitor pentoxifylline (PTX) has anti-inflammatory and antifibrotic effects in multiple organs. It was hypothesized that PTX would have a protective effect on hyperoxia-induced lung injury (HILI). METHODS: Newborn Sprague-Dawley rats were exposed to >95% oxygen (O(2)) and injected subcutaneously with normal saline (NS) or PTX (75 mg/kg) twice a day for 9 d. NS-injected, room air-exposed pups were controls. At days 4 and 9, lung tissue was collected to assess edema, antioxidant enzyme (AOE) activities, and vascular endothelial growth factor (VEGF) expression. At day 9, pulmonary macrophage infiltration, vascularization, and alveolarization were also examined. RESULTS: At day 9, treatment with PTX significantly increased survival from 54% to 88% during hyperoxia. Treatment with PTX significantly decreased lung edema and macrophage infiltration. PTX treatment increased lung AOE activities including those of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPX). Furthermore, PTX treatment also increased the gene expression of VEGF189 and VEGF165, increased VEGF protein expression, and improved pulmonary vascularization. DISCUSSION: These data indicate that the reduced lung edema and inflammation, increased AOE activities, and improved vascularization may be responsible for the improved survival with PTX during hyperoxia. PTX may be a potential therapy in reducing some of the features of BPD in preterm newborns.

Timing of patent ductus arteriosus treatment and respiratory outcome in premature infants: a double-blind randomized controlled trial.

OBJECTIVE: To determine whether "early" ibuprofen treatment, at the onset of subtle patent ductus arteriosus (PDA) symptoms, would improve respiratory outcome in premature infants compared with "expectant" management, with ibuprofen treatment only when the PDA becomes hemodynamically significant (HS). STUDY DESIGN: We conducted a randomized double-blind controlled trial of infants with gestational ages 23 to 32 weeks and birth weights 500 to 1250 g who had echocardiography for subtle PDA symptoms (metabolic acidosis, murmur, bounding pulses). Infants were then randomized to "early" treatment (blinded ibuprofen; n = 54) or "expectant management" (blinded placebo, n = 51). If the PDA became HS (pulmonary hemorrhage, hypotension, respiratory deterioration), infants received open label ibuprofen. Infants with HS PDA at enrollment were excluded from the study. Respiratory outcomes and mortality and major morbidities were determined. RESULTS: "Early" treatment infants received ibuprofen at median age of 3 days; infants in the "expectant group" in whom HS symptoms developed (20%) received ibuprofen at median of 11 days. A total of 49% of "expectant" infants never required ibuprofen or ligation. No significant differences were found in the primary outcome (days on oxygen [O(2)] during the first 28 days), death, O(2) at 36 weeks, death or O(2) at 36 weeks, intestinal perforation, surgical necrotizing enterocolitis, grades III and IV intracranial hemorrhage, periventricular leukomalacia, sepsis or retinopathy of prematurity. CONCLUSION: Infants with mild signs of PDA do not benefit from early PDA treatment compared with delayed treatment.

A randomized, double-blind, placebo-controlled trial on intravenous ibuprofen L-lysine for the early closure of nonsymptomatic patent ductus arteriosus within 72 hours of birth in extremely low-birth-weight infants.

A multicenter, double-blind, randomized, placebo-controlled trial was conducted to evaluate the efficacy and safety of intravenous (IV) ibuprofen (L-lysine) for the early closure of nonsymptomatic patent ductus arteriosus (PDA) within 72 hours of birth in extremely low-birth-weight (ELBW) infants with evidence of ductal shunting by echocardiogram. Eleven sites enrolled 136 infants with nonsymptomatic early PDA (gestational age < 30 weeks; body weight 500 to 1000 g) to receive a 3-day course (10 mg/kg, 5 mg/kg, and 5 mg/kg) of IV ibuprofen ( N = 68) or placebo ( N = 68). Cardiac echocardiogram was performed on study days 1 and 14, and with rescue. Infants were followed to 36 weeks postconceptional age. Patient demographics, mean (standard deviation), were similar between ibuprofen and placebo: birth weight: 798.5 g (128.7) versus 797.3 g (132.8); gestational age: 26.1 weeks (1.3) versus 26.2 weeks (1.4); and age at first dose: 1.5 days (0.7). The intent-to-treat analysis of the primary endpoint, subjects rescued, died, or dropped through study day 14, was 21/68 (30.9%) with ibuprofen and 36/68 (52.9%) for placebo ( P = 0.005). Death, intraventricular hemorrhage, necrotizing enterocolitis, daily fluid intake/output, liver function, bronchopulmonary dysplasia, and retinopathy of prematurity did not differ. A trend toward decreased periventricular leukomalacia by ibuprofen was noted. IV ibuprofen was effective and safe in the early closure of PDA in preterm neonates.

IL-1 alpha causes lung inflammation and maturation by direct effects on preterm fetal lamb lungs.

Intra-amniotic endotoxin induces IL-1, causes chorioamnionitis, lung inflammation, lung injury and lung maturation in preterm lambs. Intra-amniotic IL-1alpha also causes chorioamnionitis, lung inflammation and lung maturation. We asked if IL-1alpha effects on the preterm lung are mediated by direct signaling to the lung rather than by indirect effects from the chorioamnionitis. To study IL-1 effects independently of chorioamnionitis, the lungs and the amniotic fluid were surgically separated in fetal sheep by diverting fetal lung fluid via a tracheostomy tube to a sialastic bag. A mini-osmotic pump delivered an intratracheal infusion of recombinant sheep IL-1alpha (10 microg) or saline (control) over 24 h. Preterm lambs were delivered 1d or 7d after the start of the infusion at 124d gestational age (Term = 150d). IL-1alpha recruited inflammatory cells and increased pro-inflammatory cytokine mRNA expression in the fetal lungs. Compared with controls, IL-1alpha did not alter lung antioxidant enzyme activity or alveolar numbers. IL-1alpha had minimal effects on the mRNA or protein expression of proteins essential for vascular development. IL-1alpha induced large increases in alveolar surfactant saturated phosphatidylcholine and increased lung gas volumes. Lung inflammation and maturation result from direct exposure of the fetal lung to a single cytokine - IL-1alpha.

Bronchopulmonary dysplasia: changes in pathogenesis, epidemiology and definition.

Bronchopulmonary dysplasia (BPD) continues to be one of the most common long-term complications associated with preterm birth. Its incidence is increasing as the survival of extreme premature infants improves, but its clinical presentation is milder than the original description of Northway and collaborators. In contrast to the classic BPD that was strongly related to mechanical injury and oxygen toxicity, current forms of the condition are more related to immaturity, perinatal infection and inflammation, persistent ductus arteriosus and disrupted alveolar and capillary development. Many different definitions of BPD have been proposed, most of which are based on the duration of supplemental oxygen requirement. The different definitions can produce strikingly different incidence figures, which may account for the wide variations in the condition reported in the literature. Some of the limitations of the criteria most commonly used to diagnose BPD are discussed in this article.

Intraamniotic endotoxin increases lung antioxidant enzyme activity in preterm lambs.

Proinflammatory stimulation resulting from intraamniotic endotoxin improves lung function, increases surfactant protein mRNA expression and protein content, increases alveolar and lung saturated phosphatidylcholine pools, and accelerates lung morphometric maturation in fetal sheep. The mechanism for induction of lung maturation does not involve an increase in fetal cortisol. The effect of endotoxin on the maturation of a different lung system, the antioxidant enzyme (AOE) system, has not been examined. Therefore, we hypothesized that intraamniotic endotoxin would produce acceleration of AOE activity in fetal sheep at similar doses and schedule of administration to those producing lung functional and surfactant maturation. In a dose-response study, intraamniotic injections of 1, 4, 20, or 100 mg of Escherichia coli 055:beta5 endotoxin were administered 7 d before preterm delivery of sheep at 125 d gestation. In a study examining time interval of administration before delivery, 20 mg of endotoxin was injected at either 1-, 2-, 4-, 7-, or 15-d intervals before preterm delivery at 125 d. Doses of 1-100 mg of endotoxin produced significant increases in glutathione peroxidase activity; doses of 4-100 mg significantly increased catalase activity, whereas doses of 20-100 mg resulted in significant increases in total superoxide dismutase activity. Glutathione peroxidase activity was elevated within 2 d, whereas superoxide dismutase was increased by 4 d and catalase activity increased by 7 d after endotoxin. No AOE increases were sustained for 15 d. Endotoxin increased fetal lung AOE activity at similar dosing amounts and intervals to those producing maturation of lung function and surfactant. Thus, mechanisms involving proinflammatory stimulation, unrelated to glucocorticoid hormones, can induce maturation of the AOE system of the fetal lung.