Systematic Review of Inhaled Bronchodilator and Corticosteroid Therapies in Infants with Bronchopulmonary Dysplasia: Implications and Future Directions

Inhaled bronchodilators for the prevention and treatment of chronic lung disease in preterm infants

BACKGROUND

Chronic lung disease (CLD) occurs frequently in preterm infants and is associated with respiratory morbidity. Bronchodilators have the potential effect of dilating small airways with muscle hypertrophy. Increased compliance and tidal volume, and decreased airway resistance, have been documented with the use of bronchodilators in infants with CLD. Therefore, bronchodilators are widely considered to have a role in the prevention and treatment of CLD, but there remains uncertainty as to whether they improve clinical outcomes. This is an update of the 2016 Cochrane review.

OBJECTIVES

To determine the effect of inhaled bronchodilators given as prophylaxis or as treatment for chronic lung disease (CLD) on mortality and other complications of preterm birth in infants at risk for or identified as having CLD.

SEARCH METHODS

An Information Specialist searched CENTRAL, MEDLINE, Embase, CINAHL and three trials registers from 2016 to May 2023. In addition, the review authors undertook reference checking, citation searching and contact with trial authors to identify additional studies.

SELECTION CRITERIA

We included randomised and quasi-randomised controlled trials involving preterm infants less than 32 weeks old that compared bronchodilators to no intervention or placebo. CLD was defined as oxygen dependency at 28 days of life or at 36 weeks' postmenstrual age. Initiation of bronchodilator therapy for the prevention of CLD had to occur within two weeks of birth. Treatment of infants with CLD had to be initiated before discharge from the neonatal unit. The intervention had to include administration of a bronchodilator by nebulisation or metered dose inhaler. The comparator was no intervention or placebo.

DATA COLLECTION AND ANALYSIS

We used the standard methodological procedures expected by Cochrane. Critical outcomes included: mortality within the trial period; CLD (defined as oxygen dependency at 28 days of life or at 36 weeks' postmenstrual age); adverse effects of bronchodilators, including hypokalaemia (low potassium levels in the blood), tachycardia, cardiac arrhythmia, tremor, hypertension and hyperglycaemia (high blood sugar); and pneumothorax. We used the GRADE approach to assess the certainty of the evidence for each outcome.

MAIN RESULTS

We included two randomised controlled trials in this review update. Only one trial provided useable outcome data. This trial was conducted in six neonatal intensive care units in France and Portugal, and involved 173 participants with a gestational age of less than 31 weeks. The infants in the intervention group received salbutamol for the prevention of CLD. The evidence suggests that salbutamol may result in little to no difference in mortality (risk ratio (RR) 1.08, 95% confidence interval (CI) 0.50 to 2.31; risk difference (RD) 0.01, 95% CI -0.09 to 0.11; low-certainty evidence) or CLD at 28 days (RR 1.03, 95% CI 0.78 to 1.37; RD 0.02, 95% CI -0.13 to 0.17; low-certainty evidence), when compared to placebo. The evidence is very uncertain about the effect of salbutamol on pneumothorax. The one trial with usable data reported that there were no relevant differences between groups, without providing the number of events (very low-certainty evidence). Investigators in this study did not report if side effects occurred. We found no eligible trials that evaluated the use of bronchodilator therapy for the treatment of infants with CLD. We identified no ongoing studies.

AUTHORS' CONCLUSIONS

Low-certainty evidence from one trial showed that inhaled bronchodilator prophylaxis may result in little or no difference in the incidence of mortality or CLD in preterm infants, when compared to placebo. The evidence is very uncertain about the effect of salbutamol on pneumothorax, and neither included study reported on the incidence of serious adverse effects. We identified no trials that studied the use of bronchodilator therapy for the treatment of CLD. Additional clinical trials are necessary to assess the role of bronchodilator agents in the prophylaxis or treatment of CLD. Researchers studying the effects of inhaled bronchodilators in preterm infants should include relevant clinical outcomes in addition to pulmonary mechanical outcomes.

Prescribing practices of inhaled corticosteroids for premature infants in the neonatal intensive care unit

OBJECTIVE

Despite limited safety and efficacy data, inhaled corticosteroids (ICS) are prescribed to premature infants in the neonatal intensive care unit (NICU). We examined contemporary use and risk factors for ICS use in the NICU.

STUDY DESIGN

Infants <33 weeks gestational age and <1500 gm birth weight discharged from Pediatrix Medical Group NICUs between 2010 and 2020 were included. We evaluated the association between ICS prescription and clinical characteristics using univariable and multivariable logistic regression.

RESULTS

Of 74,123 infants from 308 NICUs, 9253 (12.5%) were prescribed ICS: budesonide, fluticasone, or beclomethasone. Diagnosis of bronchopulmonary dysplasia (BPD), earlier gestational age, male sex, longer mechanical ventilation, oxygen support, and systemic steroids were independent risk factors for ICS prescription.

CONCLUSIONS

Use of ICS is common in many NICUs and is associated with a diagnosis of BPD and healthcare utilization. Prospective trials are needed to establish the safety, efficacy, and optimal indication in this vulnerable population.

Estimating the effect of diuretics and inhaled corticosteroids for evolving bronchopulmonary dysplasia in preterm infants

BACKGROUND

Off-label treatment of extremely preterm infants with diuretics and inhaled corticosteroids (ICS) for evolving bronchopulmonary dysplasia (BPD) is common. Their effectiveness in reducing mortality or BPD severity, and optimal treatment timing, are unclear.

OBJECTIVES

To determine whether diuretic treatment or ICS administration for infants with early evolving (between 10-27 days postnatal) and progressively evolving (28th-day-36th-week postnatal) BPD are independently associated with reduced mortality and moderate or severe BPD at 36-weeks postmenstrual age (PMA).

METHODS

We examined neonates born before 28 weeks' gestation and admitted to neonatal intensive care units on postnatal Day 0 between 2006 and 2016 using data collected during routine care recorded within the Paediatric Health Information System (PHIS). An early evolving BPD cohort consisted of infants treated with oxygen, positive pressure or mechanical ventilation at 10 days postnatal. The progressively evolving BPD cohort consisted of infants treated with these modalities at 28 days. In new users, we evaluated the effect of diuretic and ICS treatment on mortality or BPD severity at 36 weeks PMA, adjusting for time-dependent confounding by respiratory status using marginal structural models.

RESULTS

Early evolving BPD was present in 10,135 patients; progressively evolving BPD in 11,728. New diuretic exposure during early evolving BPD (adjusted risk ratio [aRR] 0.77, 95% confidence interval [CI] 0.65, 0.93) was associated with decreased mortality or moderate/severe BPD risk. New diuretics (aRR 0.86, 95% CI 0.75, 0.99) during progressively evolving BPD between 28-days-36-weeks PMA were less strongly associated with mortality or moderate/severe BPD reduction. There was no strong association for ICS in patients with early evolving (aRR: 1.40; 95% CI: 0.79, 2.51) or progressively evolving BPD (aRR 1.16, 95% CI 0.95, 1.49).

CONCLUSION

Diuretics, but not ICS, for evolving BPD were associated with mortality and BPD risk reduction.

Intratracheal budesonide mixed with surfactant to increase survival free of bronchopulmonary dysplasia in extremely preterm infants: study protocol for the international, multicenter, randomized PLUSS trial

BACKGROUND

Bronchopulmonary dysplasia (BPD), an inflammatory-mediated chronic lung disease, is common in extremely preterm infants born before 28 weeks' gestation and is associated with an increased risk of adverse neurodevelopmental and respiratory outcomes in childhood. Effective and safe prophylactic therapies for BPD are urgently required. Systemic corticosteroids reduce rates of BPD in the short-term but are associated with poorer neurodevelopmental outcomes if given to ventilated infants in the first week after birth. Intratracheal administration of corticosteroid admixed with exogenous surfactant could overcome these concerns by minimizing systemic sequelae. Several small, randomized trials have found intratracheal budesonide in a surfactant vehicle to be a promising therapy to increase survival free of BPD.

METHODS

An international, multicenter, double-blinded, randomized trial of intratracheal budesonide (a corticosteroid) mixed with surfactant for extremely preterm infants to increase survival free of BPD at 36 weeks' postmenstrual age (PMA; primary outcome). Extremely preterm infants aged < 48 h after birth are eligible if: (1) they are mechanically ventilated, or (2) they are receiving non-invasive respiratory support and there is a clinical decision to treat with surfactant. The intervention is budesonide (0.25 mg/kg) mixed with poractant alfa (200 mg/kg first intervention, 100 mg/kg if second intervention), administered intratracheally via an endotracheal tube or thin catheter. The comparator is poractant alfa alone (at the same doses). Secondary outcomes include the components of the primary outcome (death, BPD prior to or at 36 weeks' PMA), potential systemic side effects of corticosteroids, cost-effectiveness, early childhood health until 2 years of age, and neurodevelopmental outcomes at 2 years of age (corrected for prematurity).

DISCUSSION

Combining budesonide with surfactant for intratracheal administration is a simple intervention that may reduce BPD in extremely preterm infants and translate into health benefits in later childhood. The PLUSS trial is powered for the primary outcome and will address gaps in the evidence due to its pragmatic and inclusive design, targeting all extremely preterm infants regardless of their initial mode of respiratory support. Should intratracheal budesonide mixed with surfactant increase survival free of BPD, without severe adverse effects, this readily available intervention could be introduced immediately into clinical practice.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry ( https://www.anzctr.org.au ), ACTRN12617000322336. First registered on 28th February 2017.

Neonatal Laryngotracheal Anomalies

Respiratory distress in the neonate is one of the most common reasons for referral to a tertiary NICU, accounting for more than 20% of admissions. (1) The cause of respiratory distress can range from parenchymal lung disease to anomalies of any portion of the neonatal airway including the nose, pharynx, larynx, trachea, or bronchi. This review will focus on airway anomalies at or immediately below the level of the larynx. Although rare, those with such congenital or acquired laryngotracheal anomalies often require urgent evaluation and surgical intervention. This review describes 1) the pathophysiology associated with congenital and acquired laryngotracheal deformities in the neonate, 2) the clinical presentation and diagnostic evaluation of these anomalies, and 3) the current medical and surgical strategies available in the NICU and after discharge.

Pharmacotherapy in Bronchopulmonary Dysplasia: What Is the Evidence?

Bronchopulmonary Dysplasia (BPD) is a multifactorial disease affecting over 35% of extremely preterm infants born each year. Despite the advances made in understanding the pathogenesis of this disease over the last five decades, BPD remains one of the major causes of morbidity and mortality in this population, and the incidence of the disease increases with decreasing gestational age. As inflammation is one of the key drivers in the pathogenesis, it has been targeted by majority of pharmacological and non-pharmacological methods to prevent BPD. Most extremely premature infants receive a myriad of medications during their stay in the neonatal intensive care unit in an effort to prevent or manage BPD, with corticosteroids, caffeine, and diuretics being the most commonly used medications. However, there is no consensus regarding their use and benefits in this population. This review summarizes the available literature regarding these medications and aims to provide neonatologists and neonatal providers with evidence-based recommendations.

Established severe BPD: is there a way out? Change of ventilatory paradigms

Improved survival of extremely preterm newborn infants has increased the number of infants at risk for developing bronchopulmonary dysplasia (BPD). Despite efforts to prevent BPD, many of these infants still develop severe BPD (sBPD) and require long-term invasive mechanical ventilation. The focus of research and clinical management has been on the prevention of BPD, which has had only modest success. On the other hand, research on the management of the established sBPD patient has received minimal attention even though this condition poses large economic and health problems with extensive morbidities and late mortality. Patients with sBPD, however, have been shown to respond to treatments focused not only on ventilatory strategies but also on multidisciplinary approaches where neurodevelopmental support, growth promoting strategies, and aggressive treatment of pulmonary hypertension improve their long-term outcomes. In this review we will try to present a physiology-based ventilatory strategy for established sBPD, emphasizing a possible paradigm shift from acute efforts to wean infants at all costs to a more chronic approach of stabilizing the infant. This chronic approach, herein referred to as chronic phase ventilation, aims at allowing active patient engagement, reducing air trapping, and improving ventilation-perfusion matching, while providing sufficient support to optimize late outcomes. IMPACT: Based on pathophysiological aspects of evolving and established severe BPD in premature infants, this review presents some lung mechanical properties of the most severe phenotype and proposes a chronic phase ventilatory strategy that aims at reducing air trapping, improving ventilation-perfusion matching and optimizing late outcomes.

Response to first dose of inhaled albuterol in mechanically ventilated preterm infants

BACKGROUND

Bronchodilator responses among preterm infants are heterogeneous. Bedside measurements may identify responders.

STUDY DESIGN

Respiratory measurements (Resistance, Compliance, FiO2) and pulse oximetry (SpO2) patterns were downloaded from infants <30 weeks gestational age during the first 2 months of life. Mechanically ventilated infants who received albuterol were included (n = 33). Measurements were compared before and after first albuterol. Secondary analyses assessed subsequent doses.

RESULTS

Median gestation and birthweight were 25 3/7 weeks and 730 g, respectively. Mean Resistance decreased post-albuterol (p = 0.007). Sixty-eight percent of infants were responders based on decreased Resistance. Compliance and FiO2 did not significantly differ. Percent time in hypoxemia (SpO2 < 85%) decreased post albuterol (p < 0.02). In responders, Resistance changes diminished with subsequent administration (all p = 0.01).

CONCLUSIONS

Ventilator resistance decreased in two-thirds of preterm infants, consistent with studies that utilized formal pulmonary function testing. Albuterol had a variable effect on delivered FiO2; however, hypoxemia may be useful in evaluating albuterol response.

Evidence for the Management of Bronchopulmonary Dysplasia in Very Preterm Infants

Background: Very preterm birth often results in the development of bronchopulmonary dysplasia (BPD) with an inverse correlation of gestational age and birthweight. This very preterm population is especially exposed to interventions, which affect the development of BPD. Objective: The goal of our review is to summarize the evidence on these daily procedures and provide evidence-based recommendations for the management of BPD. Methods: We conducted a systematic literature research using MEDLINE/PubMed on antenatal corticosteroids, surfactant-replacement therapy, caffeine, ventilation strategies, postnatal corticosteroids, inhaled nitric oxide, inhaled bronchodilators, macrolides, patent ductus arteriosus, fluid management, vitamin A, treatment of pulmonary hypertension and stem cell therapy. Results: Evidence provided by meta-analyses, systematic reviews, randomized controlled trials (RCTs) and large observational studies are summarized as a narrative review. Discussion: There is strong evidence for the use of antenatal corticosteroids, surfactant-replacement therapy, especially in combination with noninvasive ventilation strategies, caffeine and lung-protective ventilation strategies. A more differentiated approach has to be applied to corticosteroid treatment, the management of patent ductus arteriosus (PDA), fluid-intake and vitamin A supplementation, as well as the treatment of BPD-associated pulmonary hypertension. There is no evidence for the routine use of inhaled bronchodilators and prophylactic inhaled nitric oxide. Stem cell therapy is promising, but should be used in RCTs only.

Pharmacologic Management of Severe Bronchopulmonary Dysplasia

Few medications are available and well tested to treat infants who already have developed or inevitably will develop severe bronchopulmonary dysplasia (sBPD). Infants who develop sBPD clearly have not benefited from decades of research efforts to identify clinically meaningful preventive therapies for very preterm infants in the first days and weeks of their postnatal lives. This review addresses challenges to individualized approaches to medication use for sBPD. Specific challenges include understanding the combination of an individual infant's postmenstrual and postnatal age and the developmental status of drug-metabolizing enzymes and receptor expression. This review will also explore the reasons for the variable responsiveness of infants to specific therapies, based on current understanding of developmental pharmacology and pharmacogenetics. Data demonstrating the remarkable variability in the use of commonly prescribed drugs for sBPD are presented, and a discussion about the current use of some of these medications is provided. Finally, the potential use of antifibrotic medications in late-stage sBPD, which is characterized by a profibrotic state, is addressed.

Impact of inhaled corticosteroids on the neurodevelopmental outcomes in chronically ventilated extremely low birth weight preterm infants

BACKGROUND

Few studies have assessed the long-term impact of inhaled corticosteroids (ICS) in preterm infants. This study evaluated the neurodevelopmental outcomes of chronically ventilated extremely low birth weight (ELBW) preterm infants exposed to ICS.

METHODS

The medical records of ELBW preterm infants admitted to two tertiary-level neonatal intensive care units from 2008 to 2014 were reviewed. Infants intubated for more than 28 days were included. The neurodevelopmental outcomes were compared at 24 months corrected age, between those with ICS exposure (inhaled group, IH) and those without it (non-inhaled group, NIH), by using the Bayley-Scale-of-Infant-and-Toddler Development-III (BSID-III).

RESULTS

Out of the 115 infants included, 64 had an ICS exposure. The incidence of the morbidities at the time of discharge, was comparable between the two groups, except for the duration of oxygen and mechanical ventilation dependence (IH 124.8 ± 40.3 days vs. NIH: 101.0 ± 28.6 days, p < 0.001 and IH 60.0 ± 25.8 days vs. NIH: 42.3 ± 14.2 days, p < 0.001, respectively). Multiple logistic regression analysis at 24 months corrected age revealed no significant differences in the BSID-III scores and in the incidence of cerebral palsy and neurodevelopmental impairment.

CONCLUSION

The late ICS exposure was not associated with neurodevelopmental impairment at 24 months corrected age in chronically ventilated ELBW infants; however, it did not reduce the duration of their dependence on oxygen and mechanical ventilation.

Utilization trends of respiratory medication in premature infants discharged on home oxygen therapy

BACKGROUND

Roughly half of all extremely preterm infants will be diagnosed with bronchopulmonary dysplasia (BPD), and a third will be discharged on home oxygen therapy (HOT). To date, there have been no studies that have examined the relationship between respiratory medication utilization in infants with BPD on HOT.

METHODS

The recorded home oximetry trial was a multicenter, randomized trial comparing two home oxygen management strategies in premature infants. Infants were enrolled at first outpatient pulmonary or neonatal intensive care unit (NICU) follow-up visit with a pulmonary component. Respiratory medication prescriptions and dosage were collected from time of enrollment through 6 months after HOT discontinuation. Patients were seen monthly while on HOT and at 1, 3, and 6 months after successful discontinuation.

RESULTS

During protocol visits, 174 (89%) infants had respiratory medications documented. Respiratory medication use was higher at initial follow-up visit compared with NICU discharge and decreased at the final 6-month follow-up visit. Infants who received inhaled steroids (IS) before weaning had mean HOT duration of 138 days (range: 24-562 days); infants who received IS after weaning had shorter mean HOT duration (55 days, range: 21-264). In time-to-event analysis the no IS group and the postwean group differed significantly (χ²₁  = 8.1; P = .004). NICU clinics gave a total of 35 prescriptions to 43 patients, an average of 0.8 per patient, while the pulmonary clinics gave 837 prescriptions to 153 patients, or 5.5 per patient (P < .0001).

CONCLUSION

Respiratory prescribing patterns for infants on HOT are highly variable. Utilization of IS was not associated with shorter duration of HOT.

Small for gestational age birth may increase airflow limitation in bronchopulmonary dysplasia

OBJECTIVES

To determine significant indices for assessing the pulmonary function of infants according to bronchopulmonary dysplasia (BPD) severity and to evaluate whether small for gestational age (SGA) could affect pulmonary function in BPD.

METHODS

We evaluated 117 preterm infants who had undergone tidal breathing flow-volume loop and multiple-breath washout analyses within 7 months after birth. We categorized preterm infants according to BPD severity into mild/moderate BPD (n = 86), severe BPD (n = 21), and without BPD (n = 10) and the presence of SGA or appropriate gestational age (AGA) using the Fenton growth chart. We evaluated nine healthy term infants as controls.

RESULTS

The tidal breathing ratio (time to peak expiratory flow/expiratory time [t_PEF /t_E ]) was significantly lower in infants with severe BPD than in those with mild/moderate BPD. Lung clearance index (LCI) was not different based on BPD severity. In the correlation analysis after adjusting for gestational age and sex, t_PEF /t_E was correlated with the duration of mechanical ventilation (r = -0.347, P < .001) and the duration of oxygen supply (r = -0.248, P = .013) in infants with BPD. The proportion of "lower t_PEF /t_E ," defined as below the cut-off value, was greater in SGA infants (P = .017), while no significant difference was seen in the percentage of "higher LCI," defined as above the cut-off value between SGA and AGA infants.

CONCLUSIONS

In infants with BPD, t_PEF /t_E could be a useful pulmonary index which shows lower values in severe BPD. The finding of SGA in infants with BPD could be associated with poor pulmonary function related to the t_PEF /t_E values.

European Respiratory Society guideline on long-term management of children with bronchopulmonary dysplasia

This document provides recommendations for monitoring and treatment of children in whom bronchopulmonary dysplasia (BPD) has been established and who have been discharged from the hospital, or who were >36 weeks of postmenstrual age. The guideline was based on predefined Population, Intervention, Comparison and Outcomes (PICO) questions relevant for clinical care, a systematic review of the literature and assessment of the evidence using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach. After considering the balance of desirable (benefits) and undesirable (burden, adverse effects) consequences of the intervention, the certainty of the evidence, and values, the task force made conditional recommendations for monitoring and treatment of BPD based on very low to low quality of evidence. We suggest monitoring with lung imaging using ionising radiation in a subgroup only, for example severe BPD or recurrent hospitalisations, and monitoring with lung function in all children. We suggest to give individual advice to parents regarding daycare attendance. With regards to treatment, we suggest the use of bronchodilators in a subgroup only, for example asthma-like symptoms, or reversibility in lung function; no treatment with inhaled or systemic corticosteroids; natural weaning of diuretics by the relative decrease in dose with increasing weight gain if diuretics are started in the neonatal period; and treatment with supplemental oxygen with a saturation target range of 90-95%. A multidisciplinary approach for children with established severe BPD after the neonatal period into adulthood is preferable. These recommendations should be considered until new and urgently needed evidence becomes available.

Tracheomalacia in bronchopulmonary dysplasia: Trachealis hyper-relaxant responses to S-nitrosoglutathione in a hyperoxic murine model

BACKGROUND

Bronchopulmonary dysplasia (BPD) with airway hyperreactivity is a long-term pulmonary complication of prematurity. The endogenous nonadrenergic, noncholinergic signaling molecule, S-nitrosoglutathione (GSNO) and its catabolism by GSNO reductase (GSNOR) modulate airway reactivity. Tracheomalacia is a major, underinvestigated complication of BPD. We studied trachealis, left main bronchus (LB), and intrapulmonary bronchiolar (IPB) relaxant responses to GSNO in a murine hyperoxic BPD model.

METHODS

Wild-type (WT) or GSNOR knockout (KO) newborn mice were raised in 60% (BPD) or 21% (control) oxygen during the first 3 weeks of life. After room air recovery, adult trachealis, LB, and IPB smooth muscle relaxant responses to GSNO (after methacholine preconstriction) were studied using wire myographs. Studies were repeated after GSNOR inhibitor (GSNORi) pretreatment and in KO mice.

RESULTS

GSNO relaxed all airway preparations. GSNO relaxed WT BPD trachealis substantially more than WT controls (P < .05). Pharmacologic or genetic ablation of GSNOR abolished the exaggerated BPD tracheal relaxation to GSNO and also augmented BPD IPB relaxation to GSNO. LB ring contractility was not significantly different between groups or conditions. Additionally, GSNORi treatment induced relaxation of WT IPBs but not trachealis or LB.

CONCLUSION

GSNO dramatically relaxed the trachealis in our BPD model, an effect paradoxically reversed by loss of GSNOR. Conversely, GSNOR inhibition augmented IBP relaxation. These data suggest that GSNOR inhibition could benefit both the BPD trachealis and distal airways, restoring relaxant responses to those of room air controls. Because therapeutic options are limited in this high-risk population, future studies of GSNOR inhibition are needed.

Aerosol therapy in relation to retinopathy of prematurity in mechanically ventilated preterm infants

Background

Aerosol administration is increasingly being used as a therapeutic intervention for mechanically ventilated preterm infants. However, the effects of inhalation therapy on retinopathy of prematurity (ROP) have not yet been explored.

Methods

A retrospective cohort study was conducted in a tertiary level neonatal intensive care unit (NICU) from 2011 to 2013. All preterm infants with a gestational age (GA) of 24~29 weeks receiving invasive intubation for more than 1 week in the NICU were included. Infants with severe congenital anomalies were excluded. ROP was defined as stage II or greater according to medical records by ophthalmologists. A multivariate logistic regression model was used to estimate the risk of ROP in relation to inhalation therapy after adjusting for confounders.

Results

In total, 205 infants were enrolled in this study, including 154 with inhalation therapy and 51 without inhalation therapy. Univariate analyses showed an association of inhalation with the following characteristics: sex (p = 0.047), GA (p = 0.029), sepsis (p = 0.047), bronchopulmonary dysplasia (BPD) (p < 0.001), and ROP (p = 0.001). Furthermore, logistic regression analysis indicated that inhalation therapy was an independent risk factor for ROP (odds ratio (OR) = 2.639; 95% confidence interval (CI) = 1.050~6.615). In addition, infants with a GA of 24~25 weeks (OR = 6.063; 95% CI = 2.482~14.81) and 26~27 weeks (OR = 3.825; 95% CI = 1.694~8.638) were at higher risk of ROP than those with a GA of 28~29 weeks. Other factors – including sex, sepsis, BPD, and delivery mode – did not carry significant risk.

Conclusion

Aerosol therapy with pure oxygen delivery is associated with ROP. Clinicians should exercise great caution when conducting aerosol therapy with excess oxygen in mechanically ventilated preterm infants.

Advances in treating bronchopulmonary dysplasia

Introduction: Bronchopulmonary dysplasia (BPD) is a common long-term adverse complication of very premature delivery. Affected infants can suffer chronic respiratory morbidities including lung function abnormalities and reduced exercise capacity even as young adults. Many studies have investigated possible preventative strategies; however, it is equally important to identify optimum management strategies for infants with evolving or established BPD. Areas covered: Respiratory support modalities and established and novel pharmacological treatments. Expert opinion: Respiratory support modalities including proportional assist ventilation and neurally adjusted ventilatory assist are associated with short term improvements in oxygenation indices. Such modalities need to be investigated in appropriate RCTs. Many pharmacological treatments are routinely used with a limited evidence base, for example diuretics. Stem cell therapies in small case series are associated with promising results. More research is required before it is possible to determine if such therapies should be investigated in large RCTs with long-term outcomes.

Bronchopulmonary Dysplasia and Pulmonary Outcomes of Prematurity

Bronchopulmonary dysplasia (BPD) is a chronic lung disease most commonly seen in premature infants who require mechanical ventilation and oxygen therapy. Despite advances in neonatal care resulting in improved survival and decreased morbidity, limited progress has been made in reducing rates of BPD. Therapeutic options to protect the vulnerable developing lung are limited as are strategies to treat lung injury, resulting in ongoing concerns for long-term pulmonary morbidity after preterm birth. Lung protective strategies and optimal nutrition are recognized to improve pulmonary outcomes. However, characterization of late outcomes is challenged by rapid advances in neonatal care. As a result, current adult survivors reflect outdated medical practices. Although neonatal pulmonary disease tends to improve with growth, compromised respiratory health has been documented in young adult survivors of BPD. With improved survival of premature infants but limited progress in reducing rates of disease, BPD represents a growing burden on health care systems. [Pediatr Ann. 2019;48(4):e148-e153.].

Bronchopulmonary Dysplasia: An Update of Current Pharmacologic Therapies and New Approaches

Bronchopulmonary dysplasia (BPD) remains the most prevalent long-term morbidity of surviving extremely preterm infants and is associated with significant health care utilization in infancy and beyond. Recent advances in neonatal care have resulted in improved survival of extremely low birth weight (ELBW) infants; however, the incidence of BPD has not been substantially impacted by novel interventions in this vulnerable population. The multifactorial cause of BPD requires a multi-pronged approach for prevention and treatment. New approaches in assisted ventilation, optimal nutrition, and pharmacologic interventions are currently being evaluated. The focus of this review is the current state of the evidence for pharmacotherapy in BPD. Promising future approaches in need of further study will also be reviewed.

[Research progress in drug therapy for bronchopulmonary dysplasia in preterm infants]

Bronchopulmonary dysplasia (BPD) is the most common long-term complication in surviving extremely preterm infants. This may lead to pulmonary hypertension, increase late neonatal mortality, and cause abnormal neural development. There is still controversy over the efficacy, as well as advantages and disadvantages, of drug therapy for BPD in preterm infants. This article reviews the research progress in the drug therapy for BPD.

The use of inhaled corticosteroids in chronically ventilated preterm infants

Bronchopulmonary dysplasia (BPD) is the most usual reason for preterm infants to require chronic mechanical ventilation. Inflammation is a key factor underlying the lung injury leading to the development of BPD, and the rationale for use of corticosteroids in the management of ventilator-dependent preterm infants is based on their anti-inflammatory effects. Because systemic corticosteroids are associated with significant adverse effects in preterm infants, attention has turned to the use of inhaled corticosteroids (ICS) as a potentially safer therapy for BPD. The aim of this review is to discuss what is known about the efficacy and safety of ICS in chronically ventilated preterm infants. However, this has been a challenge since there is a paucity of high-grade evidence for the use of ICS in these patients. Thus, there is a real need for well-powered randomized controlled trials examining short- and long-term outcomes of ICS use in this population.

Airway Remodeling and Hyperreactivity in a Model of Bronchopulmonary Dysplasia and Their Modulation by IL-1 Receptor Antagonist

Bronchopulmonary dysplasia (BPD) is a chronic disease of extreme prematurity that has serious long-term consequences including increased asthma risk. We earlier identified IL-1 receptor antagonist (IL-1Ra) as a potent inhibitor of murine BPD induced by combining perinatal inflammation (intraperitoneal LPS to pregnant dams) and exposure of pups to hyperoxia (fraction of inspired oxygen = 0.65). In this study, we determined whether airway remodeling and hyperresponsiveness similar to asthma are evident in this model, and whether IL-1Ra is protective. During 28-day exposure to air or hyperoxia, pups received vehicle or 10 mg/kg IL-1Ra by daily subcutaneous injection. Lungs were then prepared for histology and morphometry of alveoli and airways, or for real-time PCR, or inflated with agarose to prepare precision-cut lung slices to visualize ex vivo intrapulmonary airway contraction and relaxation by phase-contrast microscopy. In pups reared under normoxic conditions, IL-1Ra treatment did not affect alveolar or airway structure or airway responses. Pups reared in hyperoxia developed a severe BPD-like lung disease, with fewer, larger alveoli, increased subepithelial collagen, and increased expression of α-smooth muscle actin and cyclin D1. After hyperoxia, methacholine elicited contraction with similar potency but with an increased maximum reduction in lumen area (air, 44%; hyperoxia, 89%), whereas dilator responses to salbutamol were maintained. IL-1Ra treatment prevented hyperoxia-induced alveolar disruption and airway fibrosis but, surprisingly, not the increase in methacholine-induced airway contraction. The current study is the first to demonstrate ex vivo airway hyperreactivity caused by systemic maternal inflammation and postnatal hyperoxia, and it reveals further preclinical mechanistic insights into IL-1Ra as a treatment targeting key pathophysiological features of BPD.

Bronchopulmonary Dysplasia: Chronic Lung Disease of Infancy and Long-Term Pulmonary Outcomes

Bronchopulmonary dysplasia (BPD) is a chronic lung disease most commonly seen in premature infants who required mechanical ventilation and oxygen therapy for acute respiratory distress. While advances in neonatal care have resulted in improved survival rates of premature infants, limited progress has been made in reducing rates of BPD. Lack of progress may in part be attributed to the limited therapeutic options available for prevention and treatment of BPD. Several lung-protective strategies have been shown to reduce risks, including use of non-invasive support, as well as early extubation and volume ventilation when intubation is required. These approaches, along with optimal nutrition and medical therapy, decrease risk of BPD; however, impacts on long-term outcomes are poorly defined. Characterization of late outcomes remain a challenge as rapid advances in medical management result in current adult BPD survivors representing outdated neonatal care. While pulmonary disease improves with growth, long-term follow-up studies raise concerns for persistent pulmonary dysfunction; asthma-like symptoms and exercise intolerance in young adults after BPD. Abnormal ventilatory responses and pulmonary hypertension can further complicate disease. These pulmonary morbidities, combined with environmental and infectious exposures, may result in significant long-term pulmonary sequalae and represent a growing burden on health systems. Additional longitudinal studies are needed to determine outcomes beyond the second decade, and define risk factors and optimal treatment for late sequalae of disease.

Inhaled budesonide for the prevention of bronchopulmonary dysplasia

Theoretically, administration of inhaled corticosteroids may allow for beneficial effects on the pulmonary system of infants with evolving or established bronchopulmonary dysplasia (BPD) with a lower risk of undesirable side effects compared to systemic corticosteroids. However, before deciding whether to use inhaled corticosteroids for BPD in routine clinical practice, the available randomized study data need to be considered. Currently published systematic reviews from the Cochrane Collaboration conclude that there is no role for inhaled corticosteroids in neither prevention nor treatment of BPD outside clinical trials. In contrast multiple observational studies indicate that a large number of preterm infants in Europe, North America and East Asia receive inhaled corticosteroids for this indication in routine clinical care. This discrepancy between evidence and practice prompted a large randomized controlled trial (RCT) investigating the role of inhaled budesonide for the prevention of BPD which was recently published and showed a significant reduction in the incidence of BPD. However, the primary outcome (a composite of death or BPD at 36 weeks postmenstrual age) was only of borderline significance as a result of a non-significant trend to increased mortality in the budesonide group. Results of the long-term follow up from this study should be considered when defining the future role of inhaled corticosteroids for BPD. Additionally, updated systematic reviews will help to determine whether the observed mortality difference between the two comparison groups represents truth or artifact.