Inhaled versus systemic corticosteroids for the treatment of chronic lung disease in ventilated very low birth weight preterm infants

Efficacy and safety of pulmonary application of corticosteroids in preterm infants with respiratory distress syndrome: a systematic review and meta-analysis

BACKGROUND

Systemic corticosteroids as the frontline treatment of respiratory distress syndrome (RDS) in preterm infants are associated with adverse effects on growth and neurodevelopmental outcome, but the pulmonary administration of steroids may help prevent the development of bronchopulmonary dysplasia (BPD) without these side effects.

OBJECTIVES

To evaluate the efficacy and safety of pulmonary application of corticosteroids in preterm infants with RDS.

METHODS

MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, ClinicalTrials.gov, the WHO's International Clinical Trials Registry and grey literature were searched with no restriction on date and language of publication from inception to May 2016. Using a random-effect model, we pooled data from randomised controlled trials (RCTs) comparing inhaled or endotracheal corticosteroids with the standard of care, placebo or no other intervention in preterm infants with RDS.

RESULTS

We identified 873 potential citations and included 12 unique RCTs. Pulmonary corticosteroid therapy was associated with a significant reduction in the composite outcome of BPD or death (relative risk (RR) 0.85, 95% CI 0.76 to 0.96). Pulmonary application of corticosteroids significantly reduced the incidence of patent ductus arteriosus (PDA) (RR 0.82, 95% CI 0.74 to 0.92) and pneumonia (RR 0.57, 95% CI 0.35 to 0.92). There was no evidence of a significant difference regarding the risk of neurodevelopmental impairment or other side effects.

CONCLUSIONS

Pulmonary administration of corticosteroids reduces the incidence of BPD or death, pneumonia, PDA without causing any major side effects in preterm infants with RDS.

Inhaled versus systemic corticosteroids for the treatment of bronchopulmonary dysplasia in ventilated very low birth weight preterm infants

BACKGROUND

This is an update of a review published in 2012. A related review "Inhaled versus systemic corticosteroids for preventing bronchopulmonary dysplasia in ventilated very low birth weight preterm neonates" has been updated as well. Bronchopulmonary dysplasia (BPD) is a serious and common problem among very low birth weight infants, despite the use of antenatal steroids and postnatal surfactant therapy to decrease the incidence and severity of respiratory distress syndrome. Due to their anti-inflammatory properties, corticosteroids have been widely used to treat or prevent BPD. However, the use of systemic steroids has been associated with serious short- and long-term adverse effects. Administration of corticosteroids topically through the respiratory tract may result in beneficial effects on the pulmonary system with fewer undesirable systemic side effects.

OBJECTIVES

To compare the effectiveness of inhaled versus systemic corticosteroids administered to ventilator-dependent preterm neonates with birth weight ≤ 1500 g or gestational age ≤ 32 weeks after 7 days of life on the incidence of death or BPD at 36 weeks' postmenstrual age.

SEARCH METHODS

We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL 2017, Issue 1), MEDLINE via PubMed (1966 to 23 February 2017), Embase (1980 to 23 February 2017), and CINAHL (1982 to 23 February 2017). We also searched clinical trials registers, conference proceedings and the reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials comparing inhaled versus systemic corticosteroid therapy (irrespective of dose and duration) starting after the first week of life in ventilator-dependent very low birth weight infants.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by the Cochrane Collaboration.

MAIN RESULTS

We included three trials that involved a total of 431 participants which compared inhaled versus systemic corticosteroids to treat BPD. No new trials were included for the 2017 update.Although one study randomised infants at < 72 hours (N = 292), treatment started when infants were aged > 15 days. In this larger study, deaths were included from the point of randomisation and before treatment started. Two studies (N = 139) randomised and started treatment at 12 to 21 days.Two trials reported non-significant differences between groups for the primary outcome: incidence of death or BPD at 36 weeks' postmenstrual age among all randomised infants. Estimates for the largest trial were Relative risk (RR) 1.04 (95% Confidence interval (CI) 0.86 to 1.26), Risk difference (RD) 0.03 (95% CI -0.09 to 0.15); (moderate-quality evidence). Estimates for the other trial reporting the primary outcome were RR 0.94 (95% CI 0.83 to 1.05), RD -0.06 (95% CI -0.17 to 0.05); (low-quality evidence).Secondary outcomes that included data from all three trials showed no significant differences in the duration of mechanical ventilation or supplemental oxygen, length of hospital stay, or the incidence of hyperglycaemia, hypertension, necrotising enterocolitis, gastrointestinal bleed, retinopathy of prematurity or culture-proven sepsis moderate- to low-quality evidence).In a subset of 75 surviving infants who were enrolled from the United Kingdom and Ireland, there were no significant differences in developmental outcomes at seven years of age between groups (moderate-quality evidence). One study received grant support and the industry provided aerochambers and metered dose inhalers of budesonide and placebo for the same study. No conflict of interest was identified.

AUTHORS' CONCLUSIONS

We found no evidence that inhaled corticosteroids confer net advantages over systemic corticosteroids in the management of ventilator-dependent preterm infants. There was no evidence of difference in effectiveness or adverse event profiles for inhaled versus systemic steroids.A better delivery system guaranteeing selective delivery of inhaled steroids to the alveoli might result in beneficial clinical effects without increasing adverse events.To resolve this issue, studies are needed to identify the risk/benefit ratio of different delivery techniques and dosing schedules for administration of these medications. The long-term effects of inhaled steroids, with particular attention to neurodevelopmental outcomes, should be addressed in future studies.

Managing Children with Bronchopulmonary Dysplasia

Bronchopulmonary dysplasia is one of the most significant early childhood chronic respiratory diseases. The article features modern approaches to preventing, diagnosing and treating broncho-pulmonary dysplasia, as well as ways of preventing complications and undesirable disease outcomes in patients older than 3 years. Members of professional associations — Union of Pediatricians of Russia and Russian Association of Perinatal Medicine Specialists — have summarized the experience of managing this category of patients at leading Russian pediatric centers according to the principles of evidence-based medicine and have provided scientific and practical data corresponding to the world level of knowledge with regard to the present problem.

HIF-1α Plays a Critical Role in the Gestational Sidestream Smoke-Induced Bronchopulmonary Dysplasia in Mice

Rationale

Smoking during pregnancy increases the risk of bronchopulmonary dysplasia (BPD) and, in mice, gestational exposure to sidestream cigarette smoke (SS) induces BPD-like condition characterized by alveolar simplification, impaired angiogenesis, and suppressed surfactant protein production. Normal fetal development occurs in a hypoxic environment and nicotinic acetylcholine receptors (nAChRs) regulate the hypoxia-inducible factor (HIF)-1α that controls apoptosis and angiogenesis. To understand SS-induced BPD, we hypothesized that gestational SS affected alveolar development through HIF-1α.

Methods

Pregnant BALB/c mice were exposed to air (control) or SS throughout the gestational period and the 7-day-old lungs of the progeny were examined.

Results

Gestational SS increased apoptosis of alveolar and airway epithelial cells. This response was associated with increased alveolar volumes, higher levels of proapoptotic factors (FOXO3a, HIPK2, p53, BIM, BIK, and BAX) and the antiangiogenic factor (GAX), and lower levels of antiapoptotic factors (Akt-PI3K, NF-κB, HIF-1α, and Bcl-2) in the lung. Although gestational SS increased the cells containing the proangiogenic bombesin-like-peptide, it markedly decreased the expression of its receptor GRPR in the lung. The effects of SS on apoptosis were attenuated by the nAChR antagonist mecamylamine.

Conclusions

Gestational SS-induced BPD is potentially regulated by nAChRs and associated with downregulation of HIF-1α, increased apoptosis of epithelial cells, and increased alveolar volumes. Thus, in mice, exposure to sidestream tobacco smoke during pregnancy promotes BPD-like condition that is potentially mediated through the nAChR/HIF-1α pathway.

An update on pharmacologic approaches to bronchopulmonary dysplasia

Bronchopulmonary dysplasia (BPD) is the most prevalent long-term morbidity in surviving extremely preterm infants and is linked to increased risk of reactive airways disease, pulmonary hypertension, post-neonatal mortality, and adverse neurodevelopmental outcomes. BPD affects approximately 20% of premature newborns, and up to 60% of premature infants born before completing 26 weeks of gestation. It is characterized by the need for assisted ventilation and/or supplemental oxygen at 36 weeks postmenstrual age. Approaches to prevention and treatment of BPD have evolved with improved understanding of its pathogenesis. This review will focus on recent advancements and detail current research in pharmacotherapy for BPD. The evidence for both current and potential future experimental therapies will be reviewed in detail. As our understanding of the complex and multifactorial pathophysiology of BPD changes, research into these current and future approaches must continue to evolve.

Current pharmacologic approaches for prevention and treatment of bronchopulmonary dysplasia

Bronchopulmonary dysplasia (BPD) is a major complication of preterm birth and has serious adverse long-term health consequences. The etiology of BPD is complex, multifactorial, and incompletely understood. Contributing factors include ventilator-induced lung injury, exposure to toxic oxygen levels, and infection. Several preventive and therapeutic strategies have been developed with variable success. These include lung protective ventilator strategies and pharmacological and nutritional interventions. These strategies target different components and stages of the disease process and they are commonly used in combination. The purpose of this review is to discuss the evidence for current pharmacological interventions and identify future therapeutic modalities that appear promising in the prevention and management of BPD. Continued improved understanding of BPD pathogenesis leads to opportunities for newer preventive approaches. These will need to be evaluated in the setting of current clinical practice in order to assess their efficacy.

Postnatal corticosteroids for bronchopulmonary dysplasia

Corticosteroids are used to improve lung function in infants who are progressing toward bronchopulmonary dysplasia. Corticosteroids facilitate extubation, but there is conflicting information about adverse effects on the developing brain. An approach to minimizing risk is to use low-dose, short-duration treatments in the highest risk ventilator-dependent patients. Questions remain about which corticosteroid is the safest and how to dose that corticosteroid.

How has research in the past 5 years changed my clinical practice

This article discusses how research in the past 5 years into management strategies influencing respiratory outcomes has changed (or not changed) the author's clinical practice. Changes include using inhaled nitric oxide but no longer systemic pulmonary vasodilators in term born infants with pulmonary hypertension. Use of postnatal steroids is now restricted to systemic administration in infants with severe respiratory failure and who are ventilator dependent beyond 2 weeks of age. Infants with bronchopulmonary dysplasia, unless they have pulmonary hypertension, are maintained at oxygen saturation levels of 90-92% rather than >/=95%. Supine sleeping is instituted in prematurely born infants without contraindications several weeks prior to neonatal discharge to reinforce to parents the importance of supine sleeping their baby at home. Further research is required to identify the optimal respiratory support strategy, particularly for very immature infants.

Progress in Discovery and Evaluation of Treatments to Prevent Bronchopulmonary Dysplasia

BACKGROUND

Recent improvements in the survival of extremely preterm infants have been accompanied by evolution in the pathogenesis and histopathology of bronchopulmonary dysplasia (BPD). Although oxygen and barotrauma-induced injury remain important contributing factors, pulmonary developmental arrest appears to play an equally important causal role in prolonged respiratory illness, especially among the most immature surviving preterm newborns. To date, clinical trials have failed to demonstrate a substantial benefit of a single treatment or preventive strategy for BPD.

OBJECTIVES

To evaluate the current evidence in favor of treatments that might prevent BPD.

METHODS

Review of clinical studies of preventive treatment strategies for BPD.

RESULTS

High frequency oscillatory ventilation, permissive hypercapnea, and inhaled nitric oxide might offer benefit to infants at risk of BPD. These and other potential preventive therapies for BPD, such as superoxide dismutase, inositol, and alpha(1)-proteinase inhibitor, deserve further study.

CONCLUSIONS

Although some current treatments offer promise, no preventive therapy for BPD has proven safe and effective, except for intramuscular vitamin A. Additional studies of respiratory technologies, management strategies, and protective molecules are needed.

Dose response to rhCC10-augmented surfactant therapy in a lamb model of infant respiratory distress syndrome: physiological, inflammatory, and kinetic profiles

While surfactant (SF) therapy alone improves respiratory distress syndrome (RDS)-associated gas exchange and lung stability, absence of anti-inflammatory proteins limits efficacy with respect to inflammation. Clara cell secretory protein (CC10), deficient in preterm infants, prevents SF degradation and has anti-inflammatory properties. In this study, intratracheal recombinant human (rh) CC10 (Claragen)-augmented SF (Survanta, Ross) therapy was examined in a premature lamb model of RDS with respect to inflammation and kinetic dose-response profiles. Preterm lambs (n = 24; gestational age: 126 +/- 3 days) were delivered via cesarean section, sedated, ventilated, and randomized into groups: 100 mg/kg SF, 100 mg/kg SF followed by 0.5 mg/kg rhCC10, 100 mg/kg SF followed by 1.5 mg/kg rhCC10, and 100 mg/kg SF followed by 5.0 mg/kg rhCC10. Arterial blood chemistry and lung mechanics were monitored; lungs were lavaged and snap-frozen after 4 h. TNF-alpha, IL-8 in plasma; TNF-alpha, IL-6, IL-8, myeloperoxidase in lung; and rhCC10 in plasma, urine, bronchoalveolar lavage, and lung were analyzed. Improvement in compliance, peak inspiratory pressure, and ventilatory efficiency index were greatest (P < 0.05) with SF + 5.0 mg/kg rhCC10. Plasma, urine, bronchoalveolar lavage, and lung [rhCC10] (where brackets denote concentration) increased (P < 0.01) with dose. Plasma [IL-8] was lower (P < 0.05) with rhCC10 than SF alone. Treatment with at least 1.5 mg/kg rhCC10 resulted in lower (P < 0.05) lung [TNF-alpha], [IL-8], and [myeloperoxidase]; SF + 1.5 mg/kg rhCC10 group had lower (P < 0.05) lung [IL-6], compared with all other groups. Compared with SF alone, SF augmented with at least 1.5 mg/kg rhCC10 decreased RDS-induced lung and systemic inflammation. Given that inflammation may lead to functional compromise, these data suggest that early intervention with rhCC10 may enhance SF therapy and warrant longer duration studies to determine its role to decrease long-term complications of ventilator management.