Stopping the swinging pendulum of postnatal corticosteroid use

Prophylactic early low-dose hydrocortisone and survival without bronchopulmonary dysplasia among extremely preterm infants born at 22-27 weeks' gestation

OBJECTIVE

To compare survival without BPD among extremely preterm infants (EPI) who received prophylactic early low-dose hydrocortisone (PEH) with those who did not (non-PEH).

STUDY DESIGN

This single-center retrospective study compared risk-adjusted rates of survival without BPD, BPD, bowel perforation, and late-onset sepsis among infants (22-27 weeks' gestation at birth) who received PEH (n = 82) and who did not (n = 205).

RESULTS

Infants in the PEH group were of lower gestational age, lower birthweight, and higher day-1 risk of death/BPD. After adjusting for risk of death/BPD, PEH-treated infants demonstrated increased survival without BPD (aOR 2.04, 95%CI 1.1-3.7), and lower BPD rates (aOR 0.46, 95%CI 0.25-0.87). Importantly, bowel perforation or sepsis rate were similar among both groups.

CONCLUSION

After risk adjustment, PEH-treated infants demonstrated improved survival without BPD and did not increase rates of bowel perforation or sepsis. In our cohort of infants, PEH was safe and effective among the sickest preterm neonates.

Personalized lung care: Bronchopulmonary dysplasia risk prediction tool tailored for neonates born in resource-limited settings

PURPOSE

Predicting bronchopulmonary dysplasia (BPD) to assess the risk-benefit of therapy is necessary considering the side effects of medications. We developed and validated an instrument for predicting BPD and compared it with an instrument currently used for neonates born in a Brazilian hospital.

METHODS

This was a retrospective cohort study of patients born between 2016 and 2020 with a gestational age (GA) between 23 and 30 weeks. Predictive equations were elaborated using methods of component variable selection collected on the 14th day of life; 70% of the sample was randomly selected for the construction of risk prediction equations and the remaining 30% for their validation, application, and comparison with the National Institute of Child Health and Human Development (NICHD) instrument. The sensitivity, specificity, and predictive values of the equations were calculated.

RESULTS

The equation that used variables with p < 5% in Fisher's exact test presented the best results: specificity of 98% and positive predictive value of 93% and could be used for BPD prediction of all small-for-gestational-age (SGA) infants. The NICHD calculator applied to our population had a specificity of 93% and a positive predictive value of 75% and could not be applied to extremely SGA infants.

CONCLUSION

Our tool can predict the risk of BPD on the 14th day of life, has higher specificity and positive predictive value to our population than the NICHD instrument, and can be suitable for SGA infants. The results must be confirmed by applying it to other populations to validate our tool.

Postnatal Corticosteroids To Prevent Bronchopulmonary Dysplasia

Bronchopulmonary dysplasia (BPD) is a common, severe chronic respiratory disease that affects very preterm infants. In utero and postnatal exposure to proinflammatory stimuli contribute to the pathophysiology of BPD. Corticosteroids, because of their potent anti-inflammatory properties, may decrease respiratory morbidity and reduce the risk of BPD in very preterm infants. However, these medications can have adverse effects on the developing brain and other organ systems. This review examines current evidence on the risks and benefits of postnatal corticosteroids used to prevent BPD in preterm infants.

Assessment of Corticosteroid Therapy and Death or Disability According to Pretreatment Risk of Death or Bronchopulmonary Dysplasia in Extremely Preterm Infants

Importance

Meta-analyses suggest that corticosteroids may be associated with increased survival without cerebral palsy in infants at high risk of bronchopulmonary dysplasia (BPD) but are associated with adverse neurologic outcomes in low-risk infants. Whether this association exists in contemporary practice is uncertain because most randomized clinical trials administered corticosteroids earlier and at higher doses than currently recommended.

Objective

To evaluate whether the pretreatment risk of death or grade 2 or 3 BPD at 36 weeks' postmenstrual age modified the association between postnatal corticosteroid therapy and death or disability at 2 years' corrected age in extremely preterm infants.

Design, Setting, and Participants

This cohort study analyzed data on 482 matched pairs of infants from 45 participating US hospitals in the National Institute of Child Health and Human Development Neonatal Research Network Generic Database (GDB). Infants were included in the cohort if they were born at less than 27 weeks' gestation between April 1, 2011, and March 31, 2017; survived the first 7 postnatal days; and had 2-year death or developmental follow-up data collected between January 2013 and December 2019. Corticosteroid-treated infants were propensity score matched with untreated controls. Data were analyzed from September 1, 2019, to November 30, 2022.

Exposure

Systemic corticosteroid therapy to prevent BPD that was initiated between day 8 and day 42 after birth.

Main Outcomes and Measures

The primary outcome was death or moderate to severe neurodevelopmental impairment at 2 years' corrected age. The secondary outcome was death or moderate to severe cerebral palsy at 2 years' corrected age.

Results

A total of 482 matched pairs of infants (mean [SD] gestational age, 24.1 [1.1] weeks]; 270 males [56.0%]) were included from 656 corticosteroid-treated infants and 2796 potential controls. Most treated infants (363 [75.3%]) received dexamethasone. The risk of death or disability associated with corticosteroid therapy was inversely associated with the estimated pretreatment probability of death or grade 2 or 3 BPD. The risk difference for death or neurodevelopmental impairment associated with corticosteroids decreased by 2.7% (95% CI, 1.9%-3.5%) for each 10% increase in the pretreatment risk of death or grade 2 or 3 BPD. This risk transitioned from estimated net harm to benefit when the pretreatment risk of death or grade 2 or 3 BPD exceeded 53% (95% CI, 44%-61%). For death or cerebral palsy, the risk difference decreased by 3.6% (95% CI, 2.9%-4.4%) for each 10% increase in the risk of death or grade 2 or 3 BPD and transitioned from estimated net harm to benefit at a pretreatment risk of 40% (95% CI, 33%-46%).

Conclusions and Relevance

Results of this study suggested that corticosteroids were associated with a reduced risk of death or disability in infants at moderate to high pretreatment risk of death or grade 2 or 3 BPD but with possible harm in infants at lower risk.

Contributions of the NICHD neonatal research network to the diagnosis, prevention, and treatment of bronchopulmonary dysplasia

Despite improvements in the care and outcomes of infants born extremely preterm, bronchopulmonary dysplasia (BPD) remains a common and frustrating complication of prematurity. This review summarizes the BPD-focused research conducted by the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network (NRN). To improve disease classification and outcome prediction, the NRN developed new data-driven diagnostic criteria for BPD and web-based tools that allow clinicians and investigators to reliably estimate BPD risk in preterm infants. Randomized trials of intramuscular vitamin A and prophylactic nasal continuous positive airway pressure conducted by the NRN have contributed to our current use of these therapies as evidence-based approaches to reduce BPD risk. A recent large, randomized trial of hydrocortisone administered beginning between the 2nd and 4th postnatal weeks provided strong evidence that this therapy promotes successful extubation but does not lower BPD rates. Ongoing studies within the NRN will address important, unanswered questions on the risks and benefits of intratracheal surfactant/corticosteroid combinations and treatment versus expectant management of the patent ductus arteriosus to prevent BPD.

Using quality improvement to implement consensus guidelines for postnatal steroid treatment of preterm infants with developing bronchopulmonary dysplasia

OBJECTIVE

Achieve over 90% adherence to consensus guidelines on use of postnatal steroids (PNS) in preterm infants for bronchopulmonary dysplasia (BPD) within 6 months.

METHODS

A multidisciplinary team formulated and implemented consensus guidelines using the Plan-Do-Study-Act method of quality improvement. Outcome measure was rate of compliance to guidelines, process measure was age of starting PNS treatment, and balancing measure was rate of repeat steroid courses.

RESULTS

Retrospective application of guidelines to preceding 10 months showed mean baseline compliance rate of 71% (n = 42). After implementation, compliance escalated to a mean rate of 96% within 6 months. Rate of PNS treatment ≤ 30 days of life increased from 50 to 80%, while rate of repeat PNS was unchanged.

CONCLUSIONS

Compliance with new guidelines for PNS treatment of BPD was quickly attained using simple quality improvement interventions. Further study is needed to evaluate effects of these guidelines on clinical outcomes.

Lung disease and pulmonary hypertension in the premature infant

The premature infant is born into the world unprepared to naturally thrive in a foreign environment. Lung development entails immense growth, structural remodeling and differentiation of specialized cells during the normal term perinatal and postnatal periods. Thus, the premature infant presents with a lung deficient for appropriate respiration. Disruption of lung development seen in bronchopulmonary dysplasia (BPD) and chronic lung disease (CLD) results in not only impaired airway growth but also a deficiency in the accompanying vasculature including the capillary system required for gas exchange. Deficient vascular area can lead to elevated pulmonary vascular resistance and the development of pulmonary hypertension (PH). Unlike PH seen in children and adults with pulmonary arterial hypertension (PAH), treatment with conventional pulmonary vasodilators can be limited in developmental lung disease-associated PH because there are fewer blood vessels to dilate. In this brief review, we highlight some of the knowledge on PH in the premature infant presented at the Proceedings of the 22^nd Annual Update on Pediatric and Congenital Cardiovascular Disease.

Are all stem cells equal? Systematic review, evidence map, and meta-analyses of preclinical stem cell-based therapies for bronchopulmonary dysplasia

Regenerative stem cell-based therapies for bronchopulmonary dysplasia (BPD), the most common preterm birth complication, demonstrate promise in animals. Failure to objectively appraise available preclinical data and identify knowledge gaps could jeopardize clinical translation. We performed a systematic review and network meta-analysis (NMA) of preclinical studies testing cell-based therapies in experimental neonatal lung injury. Fifty-three studies assessing 15 different cell-based therapies were identified: 35 studied the effects of mesenchymal stromal cells (MSCs) almost exclusively in hyperoxic rodent models of BPD. Exploratory NMAs, for select outcomes, suggest that MSCs are the most effective therapy. Although a broad range of promising cell-based therapies has been assessed, few head-to-head comparisons and unclear risk of bias exists. Successful clinical translation of cell-based therapies demands robust preclinical experimental design with appropriately blinded, randomized, and statistically powered studies, based on biological plausibility for a given cell product, in standardized models and endpoints with transparent reporting.

Randomized Trial of 42-Day Compared with 9-Day Courses of Dexamethasone for the Treatment of Evolving Bronchopulmonary Dysplasia in Extremely Preterm Infants

OBJECTIVE

To compare pulmonary and neurodevelopmental outcomes in extremely preterm infants with evolving bronchopulmonary dysplasia treated with either a 42-day course of dexamethasone or 9-day course(s) of dexamethasone.

STUDY DESIGN

This was a prospective, randomized study in 59 infants ≤27 weeks of gestation born between October 2006 and December 2010, who at day 10-21 of life had ventilatory support with mean airway pressure ≥8 cm H₂O and FiO₂ ≥60%. Infants received dexamethasone 0.5 mg/k/day × 3 days followed by a slow taper (42-day group, n = 30) or dexamethasone 0.5 mg/k/day followed by a rapid taper (9-day group, n = 29). Infants in the 9-day group received additional 9-day courses if they again required entry support. The primary outcome was intact survival (normal neurologic examination, IQ >70, and functioning in school without supplemental educational support) at 7 years of age.

RESULTS

The 42-day and 9-day groups were similar for mean gestational age (25 weeks) and all baseline characteristics. Nineteen of 29 infants (66%) in the 9-day group received only 1 course of dexamethasone; therefore, the total steroid dose for the 42-day group (7.56 mg/kg) was significantly greater than that for the 9-day group (4.04 mg/kg), P < .001. Infants in the 42-day group had shorter duration of ventilation (25 vs 37 days), P < .005, received fewer transfusions (2 vs 3.5), P < .01, and reached full enteral feeds earlier (40 vs 46 days), P < .05. Intact survival at school age was significantly increased in the 42-day group (75%) compared with the 9-day group (34%), P < .005.

CONCLUSION

A 42-day tapering course of dexamethasone in extremely preterm infants at high risk for bronchopulmonary dysplasia decreased hospital morbidities and increased rate of survival without handicap compared with a treatment protocol that attempted to minimize steroid exposure.

Usefulness of an Online Risk Estimator for Bronchopulmonary Dysplasia in Predicting Corticosteroid Treatment in Infants Born Preterm

OBJECTIVE

To assess the usefulness of a bronchopulmonary dysplasia (BPD) outcome estimator developed by the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) in identifying high-risk preterm infants treated with steroids.

STUDY DESIGN

This was a single-center retrospective study of infants born ≤30 weeks of gestational age. The NICHD BPD outcome estimator was used to retrospectively calculate BPD risk at various postnatal ages. The best combination of risk estimates for identifying steroid treatment was identified using stepwise model selection. A cut-off value with the best combination of sensitivity and specificity was identified using receiver operating characteristic analysis.

RESULTS

A total of 165 infants born preterm (mean gestational age 26 ± 1.6 weeks, mean birth weight 837 ± 171 g) were included. Of these, 61 were treated with steroids for BPD and 104 were not. Risk estimates for BPD or death were significantly greater in infants treated with steroids compared with controls. Both combined risk for severe BPD or death and single risk of no BPD were identified as factors with the best predictive power for identifying treatment with steroids, with accurate prediction possible as early as the second week of life. A greater than 37% risk for severe BPD or death or a less than 3% risk of no BPD on day of life 14 had 84%-92% sensitivity and 77%-80% specificity for predicting steroid treatment.

CONCLUSION

The NICHD BPD outcome estimator can be a useful objective tool for identifying infants at high risk for BPD who may benefit from postnatal steroids.

Mesenchymal Stromal Cell Therapy in Bronchopulmonary Dysplasia: Systematic Review and Meta-Analysis of Preclinical Studies

Extreme prematurity is the leading cause of death among children under 5 years of age. Currently, there is no treatment for bronchopulmonary dysplasia (BPD), the most common complication of extreme prematurity. Experimental studies in animal models of BPD suggest that mesenchymal stromal cells (MSCs) are lung protective. To date, no systematic review and meta-analysis has evaluated the preclinical evidence of this promising therapy. Our protocol was registered with Collaborative Approach to Meta-Analysis and Review of Animal Data from Experimental Studies prior to searching MEDLINE (1946 to June 1, 2015), Embase (1947 to 2015 Week 22), Pubmed, Web of Science, and conference proceedings (1990 to present) for controlled comparative studies of neonatal animal models that received MSCs or cell free MSC-derived conditioned media (MSC-CM). Lung alveolarization was the primary outcome. We used random effects models for data analysis and followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses reporting guidelines. We screened 990 citations; 25 met inclusion criteria. All used hyperoxia-exposed neonatal rodents to model BPD. MSCs significantly improved alveolarization (Standardized mean difference of -1.330, 95% confidence interval [CI -1.724, -0.94, I2 69%]), irrespective of timing of treatment, source, dose, or route of administration. MSCs also significantly ameliorated pulmonary hypertension, lung inflammation, fibrosis, angiogenesis, and apoptosis. Similarly, MSC-CM significantly improved alveolarization, angiogenesis, and pulmonary artery remodeling. MSCs, tested exclusively in hyperoxic rodent models of BPD, show significant therapeutic benefit. Unclear risk of bias and incomplete reporting in the primary studies highlights nonadherence to reporting standards. Overall, safety and efficacy in other species/large animal models may provide useful information for guiding the design of clinical trials. Stem Cells Translational Medicine 2017;6:2079-2093.

Inhaled Drugs and Systemic Corticosteroids for Bronchopulmonary Dysplasia

All definitions of bronchopulmonary dysplasia (BPD) have limitations and a new definition for the purpose of clinical research, benchmarking, and prognostic prediction is needed. Different inhaled and systemic drugs are currently used to prevent or treat BPD. Despite some positive effects on BPD, more information about the effects of inhaled corticosteroids is required to assess overall efficacy and associated risks. One needs to balance the risks of neurodevelopmental impairment owing to systemic corticosteroids against those of BPD itself. Future studies should, therefore, focus on infants with a very high risk of developing BPD and include pharmacokinetics and long-term developmental outcomes.

Noninvasive Support: Does It Really Decrease Bronchopulmonary Dysplasia?

Noninvasive support of preterm infants with respiratory distress is an evidenced-based strategy to decrease the incidence of bronchopulmonary dysplasia. Continuous positive airway pressure (CPAP) is the only noninvasive strategy with sufficient evidence to support its use in acute respiratory distress syndrome. It is unclear if one method for delivering CPAP is superior to another. Future research will focus on strategies (eg, sustained lung inflation, and administration of surfactant using a thin plastic catheter) that increase the likelihood of success with CPAP, especially in infants with a gestational age of less than 26 weeks.

Early inhaled steroid use in extremely low birthweight infants: a randomised controlled trial

OBJECTIVE

We hypothesised that a prophylactic inhaled steroid would prevent the progression of bronchopulmonary dysplasia (BPD) in extremely low birthweight infants (ELBWIs).

DESIGN

This study was a multicentre, randomised, double-blinded, placebo-controlled trial.

SETTING

This investigation was conducted in 12 level III neonatal intensive care units (NICUs).

PATIENTS

A total of 211 ELBWIs requiring ventilator support were enrolled.

INTERVENTION

Starting within 24 h of birth and continuing until 6 weeks of age or extubation, two doses of 50 μg fluticasone propionate (FP) or placebo were administered every 24 h.

MAIN OUTCOME MEASUREMENT

The primary outcome measure used to indicate the morbidity of severe BPD incidence was death or oxygen dependence at discharge from the NICU. The secondary measures were neurodevelopmental impairments (NDIs) at 18 months of postmenstrual age and 3 years of age. We performed subgroup analyses based on gestational week (GW) and the presence of chorioamnionitis (CAM).

RESULTS

Infants were randomised into the FP (n=107) or placebo (n=104) groups. No significant differences were detected between the FP and placebo groups with respect to either the frequency of death or the oxygen dependence at discharge or NDIs. In subgroup analyses, the frequencies of death and oxygen dependence at discharge were significantly decreased in the FP group for infants born at 24-26 GWs and for infants with CAM, regardless of the GW at birth.

CONCLUSIONS

Inhaled steroids have no effect on the prevention of severe BPD or long-term NDI but might decrease the severity of BPD for ELBWIs with a risk factor.

TRIAL REGISTRATION NUMBER

UMIN-CTR C000000405.

Evidence-Based Pharmacologic Therapies for Prevention of Bronchopulmonary Dysplasia: Application of the Grading of Recommendations Assessment, Development, and Evaluation Methodology

Bronchopulmonary dysplasia (BPD) is the most common chronic complication of extreme preterm birth. The authors applied the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology to pharmacologic therapies found to prevent BPD. Caffeine and vitamin A are the only medications shown in high-quality studies to prevent BPD without the risk of clinically important adverse effects. Dexamethasone is effective for the prevention of BPD; but for many infants, the increased risks of hypertrophic cardiomyopathy, gastrointestinal perforation, and cerebral palsy outweigh this benefit. Several medications are currently under investigation for the prevention of BPD, but few are novel agents.

Neonatal glucocorticoid treatment increased depression-like behaviour in adult rats

Synthetic glucocorticoid dexamethasone (DEX) is frequently used as a therapeutic agent to lessen the morbidity of chronic lung disease in premature infants. Previous studies suggested that neonatal DEX treatment altered brain development and cognitive function. It has been recognized that the amygdala is involved in emotional processes and also a critical site of neuronal plasticity for fear conditioning. Little is known about the possible long-term adverse effect of neonatal DEX treatment on amygdala function. The present study was aimed to evaluate the possible effect of neonatal DEX treatment on the synaptic function of amygdala in adult rats. Newborn Wistar rats were subjected to subcutaneous tapering-dose injections of DEX (0.5, 0.3 and 0.1 mg/kg) from post-natal day one to three, PN1-PN3. Animals were then subjected to a forced swimming test (FST) and electrophysiological recording aged eight weeks. The results of the FST showed neonatal DEX treatment increased depression-like behaviour in adulthood. After acute stress evoking, the percentage of time spent free floating is significantly increased in the DEX treated group compared with the control animals. Furthermore, neonatal DEX treatment elevated long-term potentiation (LTP) response and the phosphorylation level of MAPK in the lateral nucleus of amygdala (LA). Intracerebroventricular infusion of the MAPK inhibitor, PD98059, showed significant rescue effects including reduced depression-like behaviour and restoration of LTP to within normal range. In conclusion, our results suggested that MAPK signalling cascade in the LA plays an important role in the adverse effect of neonatal DEX treatment on amygdala function, which may result in adverse consequences in adult age, such as the enhancement of susceptibility for a depressive disorder in later life.

An update on the impact of postnatal systemic corticosteroids on mortality and cerebral palsy in preterm infants: effect modification by risk of bronchopulmonary dysplasia

Infants at higher risk of bronchopulmonary dysplasia had increased rates of survival free of cerebral palsy after postnatal corticosteroid treatment in a previous metaregression of data from 14 randomized controlled trials. The relationship persists and is stronger in an updated analysis with data from 20 randomized controlled trials.