Effect of Prophylaxis for Early Adrenal Insufficiency Using Low-Dose Hydrocortisone in Very Preterm Infants: An Individual Patient Data Meta-Analysis

An Update on the Prevention and Management of Bronchopulmonary Dysplasia

Bronchopulmonary dysplasia (BPD) is a common morbidity affecting preterm infants and is associated with substantial long-term disabilities. There has been no change in the incidence of BPD over the past 20 years, despite improvements in survival and other outcomes. The preterm lung is vulnerable to injuries occurring as a result of invasive ventilation, hyperoxia, and infections that contribute to the development of BPD. Clinicians caring for infants in the neonatal intensive care unit use multiple therapies for the prevention and management of BPD. Non-invasive ventilation strategies and surfactant administration via thin catheters are treatment approaches that aim to avoid volutrauma and barotrauma to the preterm developing lung. Identifying high-risk infants to receive postnatal corticosteroids and undergo patent ductus arteriosus closure may help to individualize care and promote improved lung outcomes. In infants with established BPD, outpatient management is complex and requires coordination from several specialists and therapists. However, most current therapies used to prevent and manage BPD lack solid evidence to support their effectiveness. Further research is needed with appropriately defined outcomes to develop effective therapies and impact the incidence of BPD.

Early closure mechanisms of the ductus arteriosus in immature infants

AIM

According to experimental studies, cardiopulmonary distress decreases after closure of patent ductus arteriosus. However, early closure of the ductus using ibuprofen or indomethacin has failed to increase survival without serious morbidity. We review relevant data aiming to define optimal early management strategies that promote early closure of ductus arteriosus without serious adverse effects.

METHODS

Literature in English was searched selectively focusing on the potential of using acetaminophen for early closure of the ductus.

RESULTS

Prophylactic ibuprofen or indomethacin intended to close the ductus, predisposes infants to ischaemia, bleeding and immune dysfunction. Acetaminophen appears to have a similar efficacy as indomethacin or ibuprofen, and all three dose-dependently constrict the ductus. Ibuprofen and indomethacin cause non-specific inhibition of prostaglandin synthesis, while acetaminophen predominantly inhibits prostaglandin E synthesis. Owing to low CYP450 activity in infancy, acetaminophen toxicity has been rarely evident. However, increasing the dosage increases the oxidative stress. We review prophylactic treatments that may increase the safety and efficacy of acetaminophen. These include vitamin A, cysteine and glutamine, and low-dose corticosteroid supplementation.

CONCLUSION

The current challenge is to define a safe perinatal management practice that promotes cardiorespiratory adaptation in immature infants, particularly the seamless closure of the ductus before significant cardiopulmonary distress develops.

Association between Baseline Cortisol Serum Concentrations and the Effect of Prophylactic Hydrocortisone in Extremely Preterm Infants

OBJECTIVE

To define nomograms of serum cortisol values before 24 hours of postnatal life for extremely preterm infants and determine whether baseline cortisol values affect the benefit/risk ratio of prophylactic hydrocortisone to improve survival without bronchopulmonary dysplasia (BPD).

STUDY DESIGN

We performed a predefined secondary analysis of the multicenter randomized controlled PREMILOC trial that included inborn infants delivered before 28 weeks of gestation. Nomograms of baseline serum cortisol values measured in 325 enrolled patients were determined for male and female neonates and correlated to perinatal events. BPD-free survival and severe adverse events were analyzed in placebo and hydrocortisone groups according to the cortisol z score in multivariate logistic regression models.

RESULTS

Increased cortisol levels measured before 24 hours following birth were associated with a significantly higher chance of BPD-free survival only in placebo-treated infants (aOR [95% CI] 1.57 [1.08-2.27], P = .02) based on sex-specific nomograms for baseline cortisol levels. The cortisol z score for infants treated with prophylactic hydrocortisone predicted a risk of high-grade intraventricular hemorrhage (aOR [95% CI] 1.82 [1.06-3.15], P = .03) and spontaneous intestinal perforation (aOR [95% CI] 4.81 [1.34-17.22], P = .02).

CONCLUSIONS

We found no predictive value of baseline cortisol levels for BPD-free survival in infants born extremely preterm treated with hydrocortisone. However, high cortisol levels early after birth were associated with a greater risk of severe intraventricular hemorrhage and spontaneous intestinal perforation in infants treated with hydrocortisone and, therefore, a lower benefit/risk ratio for the treatment.

TRIAL REGISTRATION

EudraCT 2007-002041-20, ClinicalTrial.gov: NCT00623740.

Rates of Bronchopulmonary Dysplasia Following Implementation of a Novel Prevention Bundle

IMPORTANCE

Bronchopulmonary dysplasia (BPD) rates in the United States remain high and have changed little in the last decade.

OBJECTIVE

To develop a consistent BPD prevention bundle in a systematic approach to decrease BPD.

DESIGN, SETTING, AND PARTICIPANTS

This quality improvement study included 484 infants with birth weights from 501 to 1500 g admitted to a level 3 neonatal intensive care unit in the Kaiser Permanente Southern California system from 2009 through 2019. The study period was divided into 3 periods: 1, baseline (2009); 2, initial changes based on ongoing cycles of Plan-Do-Study-Act (2010-2014); and 3, full implementation of successive Plan-Do-Study-Act results (2015-2019).

INTERVENTIONS

A BPD prevention system of care bundle evolved with a shared mental model that BPD is avoidable.

MAIN OUTCOMES AND MEASURES

The primary outcome was BPD in infants with less than 33 weeks' gestational age (hereafter referred to as BPD <33). Other measures included adjusted BPD <33, BPD severity grade, and adjusted median postmenstrual age (PMA) at hospital discharge. Balancing measures were adjusted mortality and adjusted mortality or specified morbidities.

RESULTS

The study population included 484 infants with a mean (SD) birth weight of 1070 (277) g; a mean (SD) gestational age of 28.6 (2.9) weeks; 252 female infants (52.1%); and 61 Black infants (12.6%). During the 3 study periods, BPD <33 decreased from 9 of 29 patients (31.0%) to 3 of 184 patients (1.6%) (P < .001 for trend); special cause variation was observed. The standardized morbidity ratio for the adjusted BPD <33 decreased from 1.2 (95% CI, 0.7-1.9) in 2009 to 0.4 (95% CI, 0.2-0.8) in 2019. The rates of combined grades 1, 2, and 3 BPD decreased from 7 of 29 patients (24.1%) to 17 of 183 patients (9.3%) (P < .008 for trend). Grade 2 BPD rates decreased from 3 of 29 patients (10.3%) to 5 of 183 patients (2.7%) (P = .02 for trend). Adjusted median PMA at home discharge decreased by 2 weeks, from 38.2 (95% CI, 37.3-39.1) weeks in 2009 to 36.8 (95% CI, 36.6-37.1) weeks during the last 3 years (2017-2019) of the full implementation period. Adjusted mortality was unchanged, whereas adjusted mortality or specified morbidities decreased significantly.

CONCLUSIONS AND RELEVANCE

A sustained low rate of BPD was observed in infants after the implementation of a detailed BPD system of care.

Hydrocortisone for Preventing Mortality and Bronchopulmonary Dysplasia in Preterm Infants with or without Chorioamnionitis Exposure: A Meta-Analysis of Randomized Trials

OBJECTIVE

This study sought to assess whether infants exposed to chorioamnionitis are the optimal population to benefit the most from early postnatal hydrocortisone delivery in preventing bronchopulmonary dysplasia (BPD). This meta-analysis was conducted to discover the efficacy of hydrocortisone in preterm infants with and without chorioamnionitis.

STUDY DESIGN

From the earliest available date until March 2018, studies, review articles, and papers published in PubMed, Ovid, and Web of Science were reviewed. Randomized controlled trials comparing hydrocortisone with placebo/no intervention in preterm infants with a known status of chorioamnionitis exposure were included.

RESULTS

Early postpartum low-dose hydrocortisone prevents the combined outcome of neonatal BPD or death in infants weighing less than 1,000 g with chorioamnionitis exposure (odds ratio [95% confidence interval]: 0.52 [0.32-0.79]; risk difference: -0.15 [-0.24 to -0.06]; number needed to treat: 6 [4-16]) but not in infants without chorioamnionitis exposure. Further secondary analysis showed no significant difference between the hydrocortisone group and the placebo group in individual outcomes of BPD or death, regardless of infant exposure to chorioamnionitis.

CONCLUSION

Early application of low-dose hydrocortisone could potentially prevent BPD or death in infants weighing less than 1,000 g with exposure to chorioamnionitis. This finding provides the basis for further study in this target group.

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.

BPD treatments: The never-ending smorgasbord

Despite important advances in neonatal care, rates of bronchopulmonary dysplasia (BPD) have remained persistently high. Numerous drugs and ventilator strategies are used for the prevention and treatment of BPD. Some, such as exogenous surfactant, volume targeted ventilation, caffeine, and non-invasive respiratory support, are associated with modest but important reductions in rates of BPD and long-term respiratory morbidities. Many other therapies, such as corticosteroids, diuretics, nitric oxide, bronchodilators and anti-reflux medications, are widely used despite conflicting, limited or no evidence of efficacy and safety. This paper examines the range of therapies used for the prevention or treatment of BPD. They are classified into those supported by evidence of effectiveness, and those which are widely used despite limited evidence or unclear risk to benefit ratios. Finally, the paper explores emerging therapies and approaches which aim to prevent or reduce BPD and long-term respiratory morbidity.

Patent ductus arteriosus management and the drift towards therapeutic nihilism - What is the evidence?

The published literature on patent ductus arteriosus (PDA) management is challenging to interpret due to poorly designed trials with high rates of open label treatments, homogenisation of patients with varying physiological subtypes, poor treatment efficacy, and spontaneous closure in more mature infants. The perceived lack of clinical benefit has led to a drift away from medical and surgical treatment of all infants with a PDA. This therapeutic nihilism as a default response to PDA management fails to recognise the physiological relevance of a left-to-right shunt with early haemodynamic instability after birth and subsequent pulmonary volume overload with prolonged exposure. Clinicians need to know if therapeutic nihilism is safe. This review will provide an overview of the available data on the efficacy of known PDA treatments, conservative management and supportive care measures that are currently applied.

Optimizing practice guidelines through incorporating patient and family values and preferences

Neonatal care largely follows clinical practice guidelines and position statements developed locally by respective institutions as well as by national and international organizations. One might expect that adoption of clinical guidelines based on best available research evidence would make neonatal care practices mostly uniform. However, wide variation in clinical practice is still noted in neonatal care. Neonatal clinical guidelines are developed almost exclusively by healthcare professionals, with little or no input from families of the infants being cared for. Therefore, such variation in practice may stem not only from how the evidence is interpreted but also how caregivers and families value different outcomes that are affected by particular interventions. Acknowledging and incorporating the variability in patient and family values and preferences in clinical guidelines is an important step towards allowing shared decision making while reducing unwarranted practice variation, and thereby helping clinicians practice family-centered evidence-based medicine.

Current Insights Into Adrenal Insufficiency in the Newborn and Young Infant

Adrenal insufficiency (AI) is a potentially life-threatening condition that can be difficult to diagnose, especially if it is not considered as a potential cause of a child's clinical presentation or unexpected deterioration. Children who present with AI in early life can have signs of glucocorticoid deficiency (hyperpigmentation, hypoglycemia, prolonged jaundice, poor weight gain), mineralocorticoid deficiency (hypotension, salt loss, collapse), adrenal androgen excess (atypical genitalia), or associated features linked to a specific underlying condition. Here, we provide an overview of causes of childhood AI, with a focus on genetic conditions that present in the first few months of life. Reaching a specific diagnosis can have lifelong implications for focusing management in an individual, and for counseling the family about inheritance and the risk of recurrence.

Hydrocortisone to treat early bronchopulmonary dysplasia in very preterm infants: study protocol for a randomized controlled trial

Background

Bronchopulmonary dysplasia (BPD) is still a common complication in very premature infants. At present, there is no effective treatment for BPD. Glucocorticoids are drugs commonly used to prevent or treat BPD before and after birth. In very premature infants with high risk factors for BPD, early use of dexamethasone can reduce the rate of death and/or BPD but may cause long-term adverse neurodevelopmental outcomes. Hydrocortisone (HC), as an alternative drug to dexamethasone, has been increasingly used to prevent BPD. However, no study has reported the efficacy and safety of HC to treat early BPD diagnosed at postnatal day (PND) 28.

Methods

This study protocol is for a multicenter double-blind randomized controlled trial of low-dose HC in the treatment of early BPD. Early BPD infants will be randomly assigned to the HC treatment group or control group. Infants in the HC group will receive 0.5 mg/kg HC twice a day for 7 days and then 0.5 mg/kg HC once a day for 3 days. The control group will be given the same volume of placebo and no intervention on the basis of routine treatment. The primary outcome is survival without moderate or severe BPD at 36 weeks postmenstrual age. Secondary outcomes are the short- and long-term effects on growth, metabolism, neurodevelopment, and other possible complications.

Discussion

This trial will determine the efficacy and safety of low-dose HC administration compared to placebo for the reduction of moderate or severe BPD at 36 weeks postmenstrual age in very preterm infants with early BPD.

Trial registration

China Clinical Trial Registration Center ChiCTR1900021854. Registered on 13 March 2019.

Phenotypes of Bronchopulmonary Dysplasia

Bronchopulmonary dysplasia (BPD) is the most common chronic morbidity in preterm infants. In the absence of effective interventions, BPD is currently a major therapeutic challenge. Several risk factors are known for this multifactorial disease that results in disrupted lung development. Inflammation plays an important role and leads to persistent airway and pulmonary vascular disease. Since corticosteroids are potent anti-inflammatory agents, postnatal corticosteroids have been used widely for BPD prevention and treatment. However, the clinical responses vary to a great degree across individuals, and steroid-related complications remain major concerns. Emerging studies on the molecular mechanism of lung alveolarization during inflammatory stress will elucidate the complicated pathway and help discover novel therapeutic targets. Moreover, with the advances in metabolomics, there are new opportunities to identify biomarkers for early diagnosis and prognosis prediction of BPD. Pharmacometabolomics is another novel field aiming to identify the metabolomic changes before and after a specific drug treatment. Through this "metabolic signature," a more precise treatment may be developed, thereby avoiding unnecessary drug exposure in non-responders. In the future, more clinical, genetic, and translational studies would be required to improve the classification of BPD phenotypes and achieve individualized care to enhance the respiratory outcomes in preterm infants.

L’administration postnatale de corticostéroïdes pour prévenir ou traiter la dysplasie bronchopulmonaire chez les nouveau-nés prématurés

Les corticostéroïdes ont longtemps été administrés pendant la période postnatale pour prévenir et traiter la dysplasie bronchopulmonaire (DBP), une cause importante de morbidité et de mortalité chez les nouveau-nés prématurés. L’administration préventive de dexaméthasone pendant la première semaine de vie est liée à une augmentation du risque de paralysie cérébrale, et l’administration précoce de corticostéroïdes inhalés semble être associée à une hausse du risque de mortalité. À l’heure actuelle, aucune de ces deux approches n’est recommandée pour prévenir la DBP. Selon de nouvelles données probantes, un traitement prophylactique d’hydrocortisone à des doses physiologiques, entrepris avant 48 heures de vie sans ajout d’indométacine, améliore la survie sans DBP, et n’a pas d’effets neurodéveloppementaux indésirables à l’âge de deux ans. Les cliniciens peuvent envisager ce traitement pour les nouveau-nés les plus à risque de DBP. Il n’est pas recommandé d’entreprendre un traitement systématique de dexaméthasone pour tous les nouveau-nés sous assistance respiratoire, mais après la première semaine de vie, les cliniciens peuvent envisager un court traitement de dexaméthasone à faible dose (0,15 mg/kg/jour à 0,2 mg/kg/jour) pour certains nouveau-nés à haut risque de DBP ou atteints d’une DBP évolutive. Aucune donnée probante n’indique que l’hydrocortisone remplace la dexaméthasone avec efficacité ou innocuité dans le traitement d’une DBP évolutive ou établie. Les données à jour n’appuient pas l’administration de corticostéroïdes inhalés pour traiter la DBP.

Postnatal corticosteroids to prevent or treat bronchopulmonary dysplasia in preterm infants

Historically, postnatal corticosteroids have been used to prevent and treat bronchopulmonary dysplasia (BPD), a significant cause of morbidity and mortality in preterm infants. Administering dexamethasone to prevent BPD in the first 7 days post-birth has been associated with increasing risk for cerebral palsy, while early inhaled corticosteroids appear to be associated with an increased risk of mortality. Neither medication is presently recommended to prevent BPD. New evidence suggests that prophylactic hydrocortisone, when initiated in the first 48 hours post-birth, at a physiological dose, and in the absence of indomethacin, improves survival without BPD, with no adverse neurodevelopmental effects at 2 years. This therapy may be considered by clinicians for infants at highest risk for BPD. Routine dexamethasone therapy for all ventilator-dependent infants is not recommended, but after the first week post-birth, clinicians may consider a short course of low-dose dexamethasone (0.15 mg/kg/day to 0.2 mg/kg/day) for individual infants at high risk for, or with evolving, BPD. There is no evidence that hydrocortisone is an effective or safe alternative to dexamethasone for treating evolving or established BPD. Current evidence does not support inhaled corticosteroids for the treatment of BPD.

Recent advances in understanding and management of bronchopulmonary dysplasia

In the current era, the survival of extremely low-birth-weight infants has increased considerably because of new advances in technology; however, these infants often develop chronic dysfunction of the lung, which is called bronchopulmonary dysplasia (BPD). BPD remains an important cause of neonatal mortality and morbidity despite newer and gentler modes of ventilation. BPD results from the exposure of immature lungs to various antenatal and postnatal factors that lead to an impairment in lung development and aberrant growth of lung parenchyma and vasculature. However, we still struggle with a uniform definition for BPD that can help predict various short- and long-term pulmonary outcomes. With new research, our understanding of the pathobiology of this disease has evolved, and many new mechanisms of lung injury and repair are now known. By utilizing the novel ‘omic’ approaches in BPD, we have now identified various factors in the disease process that may act as novel therapeutic targets in the future. New investigational agents being explored for the management and prevention of BPD include mesenchymal stem cell therapy and insulin-like growth factor 1. Despite this, many questions remain unanswered and require further research to improve the outcomes of premature infants with BPD.

Drugs to Prevent Bronchopulmonary Dysplasia: Effect of Baseline Risk on the Number Needed to Treat

Infants born very preterm have a variable baseline risk of bronchopulmonary dysplasia (BPD). Using the example of evidence-based drug therapies to prevent BPD, we designed a visual aid that displays the "number needed to treat" with CIs for caffeine, vitamin A, and hydrocortisone over a range of baseline risks.

Postnatal Corticosteroids Policy for Very Preterm Infants and Bronchopulmonary Dysplasia

INTRODUCTION

Postnatal corticosteroids (PNC) are effective for reducing bronchopulmonary dysplasia (BPD) in very preterm neonates but are associated with adverse effects including an increased risk of cerebral palsy. PNC use in Europe is heterogeneous across regions. This study aimed to assess whether European neonatal intensive care units (NICUs) with a low use of PNC or an explicit policy to reduce PNC use had higher risks of mortality or BPD.

METHODS

We included 3,126 infants in 105 NICUs born between 24 + 0 and 29 + 6 weeks' gestational age in 19 regions in 11 countries in the EPICE cohort. First, we identified clusters of NICUs using hierarchical clustering based on PNC use and BPD prevalence and compared case mix and mortality between the clusters. Second, a multilevel analysis was performed to evaluate the association between a restrictive PNC policy and BPD occurrence.

RESULTS

There were 3 clusters of NICUs: 52 with low PNC use and a low BPD rate, 37 with low PNC use and a high BPD rate, and 16 with high PNC use and a medium BPD rate. Neonatal mortality did not differ between clusters (p = 0.88). A unit policy of restricted PNC use was not associated with a higher risk of BPD (odds ratio 0.68; 95% confidence interval: 0.45-1.03) after adjustment.

CONCLUSION

Up to 49% of NICUs had low PNC use and low BPD rates, without a difference in mortality. Infants hospitalized in NICUs with a stated policy of low PNC use did not have an increased risk of BPD.

Bronchopulmonary dysplasia

In the absence of effective interventions to prevent preterm births, improved survival of infants who are born at the biological limits of viability has relied on advances in perinatal care over the past 50 years. Except for extremely preterm infants with suboptimal perinatal care or major antenatal events that cause severe respiratory failure at birth, most extremely preterm infants now survive, but they often develop chronic lung dysfunction termed bronchopulmonary dysplasia (BPD; also known as chronic lung disease). Despite major efforts to minimize injurious but often life-saving postnatal interventions (such as oxygen, mechanical ventilation and corticosteroids), BPD remains the most frequent complication of extreme preterm birth. BPD is now recognized as the result of an aberrant reparative response to both antenatal injury and repetitive postnatal injury to the developing lungs. Consequently, lung development is markedly impaired, which leads to persistent airway and pulmonary vascular disease that can affect adult lung function. Greater insights into the pathobiology of BPD will provide a better understanding of disease mechanisms and lung repair and regeneration, which will enable the discovery of novel therapeutic targets. In parallel, clinical and translational studies that improve the classification of disease phenotypes and enable early identification of at-risk preterm infants should improve trial design and individualized care to enhance outcomes in preterm infants.