Effect of inhaled budesonide therapy on lung function in schoolchildren born preterm

Prematurity-associated wheeze: current knowledge and opportunities for further investigation

Prematurity-associated wheeze is a common complication of preterm birth, with significant impact on the health and healthcare utilization of former preterm infants. This wheezing phenotype remains poorly understood and difficult to predict. This review will discuss the current state of the literature on prematurity-associated wheeze. We will discuss etiology and pathophysiology, and offer two conceptual models for the pathogenesis of this complex condition. This review will also identify current methods of ascertainment, and discuss the strengths and limitations of each. We will explore research-backed approaches to prevention and management, and finally suggest both pre-clinical and clinical avenues for investigation. An in-depth understanding of prematurity-associated wheeze will aid clinicians in its diagnosis and management, and inspire scientists to pursue much-needed further study into causes and prevention of this common and impactful condition. IMPACT: There is no recent, concise review on the current state of research on prematurity-associated wheeze, which is a rapidly evolving area of study. This article highlights causal models of wheeze, methods of ascertainment, management strategies for the clinician, and opportunities for further research for the physician scientist.

Inhaled Corticosteroids Alone and in Combination With Long-Acting β2 Receptor Agonists to Treat Reduced Lung Function in Preterm-Born Children: A Randomized Clinical Trial

Importance

Decreases in future lung function are a hallmark of preterm birth, but studies for management of decreased lung function are limited.

Objective

To determine whether 12 weeks of treatment with inhaled corticosteroids (ICS) alone or in combination with long-acting β2 agonists (LABA) improves spirometry and exercise capacity in school-aged preterm-born children who had percent predicted forced expiratory volume in 1 second (%FEV1) less than or equal to 85% compared with inhaled placebo treatment.

Design, Setting, and Participants

A double-blind, randomized, placebo-controlled trial was conducted to evaluate ICS and ICS/LABA against placebo. Preterm-born children (age, 7-12 years; gestation ≤34 weeks at birth) who did not have clinically significant congenital, cardiopulmonary, or neurodevelopmental abnormalities underwent spirometry, exercise testing, and measurement of fractional exhaled nitric oxide before and after treatment. A total of 144 preterm-born children at the Children's Hospital for Wales in Cardiff, UK, were identified and enrolled between July 1, 2017, and August 31, 2019.

Interventions

Each child was randomized to 1 of 3 cohorts: fluticasone propionate, 50 μg, with placebo; fluticasone propionate, 50 μg, with salmeterol, 25 μg; or placebo inhalers, all given as 2 puffs twice daily for 12 weeks. Children receiving preexisting ICS treatment underwent washout prior to randomization to ICS or ICS/LABA.

Main Outcomes and Measures

The primary outcome was between-group differences assessed by adjusted pretreatment and posttreatment differences of %FEV1 using analysis of covariance. Intention-to-treat analysis was conducted.

Results

Of 144 preterm-born children who were identified with %FEV1 less than or equal to 85%, 53 were randomized. Treatment allocation was 20 children receiving ICS (including 5 with prerandomization ICS), 19 children receiving ICS/LABA (including 4 with prerandomization ICS), and 14 children receiving placebo. The mean (SD) age of children was 10.8 (1.2) years, and 29 of the randomized children (55%) were female. The posttreatment %FEV1 was adjusted for sex, gestation, bronchopulmonary dysplasia, intrauterine growth restriction, pretreatment corticosteroid status, treatment group, and pretreatment values. Posttreatment adjusted means for %FEV1, using analysis of covariance, were 7.7% (95% CI, -0.27% to 15.72%; P = .16) higher in the ICS group and 14.1% (95% CI, 7.3% to 21.0%; P = .002) higher in the ICS/LABA group compared with the placebo group. Active treatment decreased the fractional exhaled nitric oxide and improved postexercise bronchodilator response but did not improve exercise capacity. One child developed cough when starting inhaler treatment; no other adverse events reported during the trial could be attributed to the inhaler treatment.

Conclusions and Relevance

The results of this randomized clinical trial suggest that combined ICS/LABA treatment is beneficial for prematurity-associated lung disease in children.

Trial Registration

EudraCT number: 2015-003712-20.

Outpatient Respiratory Management of Infants, Children, and Adolescents with Post-Prematurity Respiratory Disease: An Official American Thoracic Society Clinical Practice Guideline

Background: Premature birth affects millions of neonates each year, placing them at risk for respiratory disease due to prematurity. Bronchopulmonary dysplasia is the most common chronic lung disease of infancy, but recent data suggest that even premature infants who do not meet the strict definition of bronchopulmonary dysplasia can develop adverse pulmonary outcomes later in life. This post-prematurity respiratory disease (PPRD) manifests as chronic respiratory symptoms, including cough, recurrent wheezing, exercise limitation, and reduced pulmonary function. This document provides an evidence-based clinical practice guideline on the outpatient management of infants, children, and adolescents with PPRD. Methods: A multidisciplinary panel of experts posed questions regarding the outpatient management of PPRD. We conducted a systematic review of the relevant literature. The Grading of Recommendations, Assessment, Development, and Evaluation approach was used to rate the quality of evidence and the strength of the clinical recommendations. Results: The panel members considered the strength of each recommendation and evaluated the benefits and risks of applying the intervention. In formulating the recommendations, the panel considered patient and caregiver values, the cost of care, and feasibility. Recommendations were developed for or against three common medical therapies and four diagnostic evaluations in the context of the outpatient management of PPRD. Conclusions: The panel developed recommendations for the outpatient management of patients with PPRD on the basis of limited evidence and expert opinion. Important areas for future research were identified.

Wheezing in preterm infants and children

Wheezing is a common outcome of preterm birth. This article will review the mechanisms, epidemiology, and treatment of wheezing in preterm children with and without a history of bronchopulmonary dysplasia.

Optimizing respiratory management in preterm infants: a review of adjuvant pharmacotherapies

Adjuvant respiratory therapies in preterm neonates aim to reduce long-term morbidities and mortality. Commonly utilized therapies include caffeine, systemic glucocorticosteroids, inhaled steroids, inhaled bronchodilators, and diuretics. This review discusses the available literature that supports some of these practices and points out where clinical practices are not corroborated by evidence. Therapies with no proven clinical benefit must be weighed against potential adverse effects.

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.

Predicting Lung Health Trajectories for Survivors of Preterm Birth

Rates of preterm birth (<37 weeks of gestation) are increasing worldwide. Improved perinatal care has markedly increased survival of very (<32 weeks gestation) and extremely (<28 weeks gestation) preterm infants, however, long term respiratory sequalae are common among survivors. Importantly, individual's lung function trajectories are determined early in life and tend to track over the life course. Preterm infants are impacted by antenatal, postnatal and early life perturbations to normal lung growth and development, potentially resulting in significant shifts from the "normal" lung function trajectory. This review summarizes what is currently known about the long-term lung function trajectories in survivors of preterm birth. Further, this review highlights how antenatal, perinatal and early life factors are likely to contribute to individual lung health trajectories across the life course.

Persistent and progressive long-term lung disease in survivors of preterm birth

Preterm birth accounts for approximately 11% of births globally, with rates increasing across many countries. Concurrent advances in neonatal care have led to increased survival of infants of lower gestational age (GA). However, infants born <32 weeks of GA experience adverse respiratory outcomes, manifesting with increased respiratory symptoms, hospitalisation and health care utilisation into early childhood. The development of bronchopulmonary dysplasia (BPD) - the chronic lung disease of prematurity - further increases the risk of poor respiratory outcomes throughout childhood, into adolescence and adulthood. Indeed, survivors of preterm birth have shown increased respiratory symptoms, altered lung structure, persistent and even declining lung function throughout childhood. The mechanisms behind this persistent and sometimes progressive lung disease are unclear, and the implications place those born preterm at increased risk of respiratory morbidity into adulthood. This review aims to summarise what is known about the long-term pulmonary outcomes of contemporary preterm birth, examine the possible mechanisms of long-term respiratory morbidity in those born preterm and discuss addressing the unknowns and potentials for targeted treatments.

Late (≥ 7 days) inhalation corticosteroids to reduce bronchopulmonary dysplasia in preterm infants

BACKGROUND

Bronchopulmonary dysplasia (BPD), defined as oxygen dependence at 36 weeks postmenstrual age (PMA), remains an important complication of prematurity. Pulmonary inflammation plays a central role in the pathogenesis of BPD. Attenuating pulmonary inflammation with postnatal systemic corticosteroids reduces the incidence of BPD in preterm infants but may be associated with an increased risk of adverse neurodevelopmental outcomes. Local administration of corticosteroids via inhalation might be an effective and safe alternative.

OBJECTIVES

To determine if administration of inhalation corticosteroids after the first week of life until 36 weeks PMA to preterm infants at high risk of developing BPD is effective and safe in reducing the incidence of death and BPD as separate or combined outcomes.

SEARCH METHODS

We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL 2017, Issue 4), MEDLINE via PubMed (1966 to 19 May 2017), Embase (1980 to 19 May 2017), and CINAHL (1982 to 19 May 2017). We also searched clinical trials databases, conference proceedings, and the reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials.

SELECTION CRITERIA

We included randomised controlled trials comparing inhalation corticosteroids, started ≥ 7 days postnatal age (PNA) but before 36 weeks PMA, to placebo in ventilated and non-ventilated infants at risk of BPD. We excluded trials investigating systemic corticosteroids versus inhalation corticosteroids.

DATA COLLECTION AND ANALYSIS

We collected data on participant characteristics, trial methodology, and inhalation regimens. The primary outcome was death or BPD at 36 weeks PMA. Secondary outcomes were the combined outcome death or BPD at 28 days PNA, the seperate outcomes of death and BPD at both 28 days PNA, and at 36 weeks PMA, and short-term respiratory outcomes, such as failure to extubate; total days of mechanical ventilation and oxygen use; and the need for systemic corticosteroids. We contacted the original trialists to verify the validity of extracted data and to provide missing data. We analysed all data using Review Manager 5. When possible, we performed meta-analysis using typical risk ratio (RR) for dichotomous outcomes and weighted mean difference (WMD) for continuous outcomes along with their 95% confidence intervals (CI). We analysed ventilated and non-ventilated participants separately.We used the GRADE approach to assess the quality of the evidence.

MAIN RESULTS

We included eight trials randomising 232 preterm infants in this review. Inhalation corticosteroids did not reduce the separate or combined outcomes of death or BPD. The meta-analyses of the studies showed a reduced risk in favor of inhalation steroids regarding failure to extubate at seven days (typical RR (TRR) 0.80, 95% CI 0.66 to 0.98; 5 studies, 79 infants) and at the latest reported time point after treatment onset (TRR 0.60, 95% CI 0.45 to 0.80; 6 studies, 90 infants). However, both analyses showed increased statistical heterogeneity (I² statistic 73% and 86%, respectively). Furthermore, inhalation steroids did not impact total duration of mechanical ventilation or oxygen dependency. There was a trend toward a reduction in the use of systemic corticosteroids in infants receiving inhalation corticosteroids (TRR 0.51, 95% CI 0.26 to 1.00; 4 studies, 74 infants; very low-quality evidence). There was a paucity of data on short- and long-term adverse effects. Our results should be interpreted with caution because the total number of randomised participants is relatively small, and most trials differed considerably in participant characteristics, inhalation therapy, and outcome definitions.

AUTHORS' CONCLUSIONS

Based on the results of the currently available evidence, inhalation corticosteroids initiated at ≥ 7 days of life for preterm infants at high risk of developing BPD cannot be recommended at this point in time. More and larger randomised, placebo-controlled trials are needed to establish the efficacy and safety of inhalation corticosteroids.

S-Nitrosoglutathione Attenuates Airway Hyperresponsiveness in Murine Bronchopulmonary Dysplasia

Bronchopulmonary dysplasia (BPD) is characterized by lifelong obstructive lung disease and profound, refractory bronchospasm. It is observed among survivors of premature birth who have been treated with prolonged supplemental oxygen. Therapeutic options are limited. Using a neonatal mouse model of BPD, we show that hyperoxia increases activity and expression of a mediator of endogenous bronchoconstriction, S-nitrosoglutathione (GSNO) reductase. MicroRNA-342-3p, predicted in silico and shown in this study in vitro to suppress expression of GSNO reductase, was decreased in hyperoxia-exposed pups. Both pretreatment with aerosolized GSNO and inhibition of GSNO reductase attenuated airway hyperresponsiveness in vivo among juvenile and adult mice exposed to neonatal hyperoxia. Our data suggest that neonatal hyperoxia exposure causes detrimental effects on airway hyperreactivity through microRNA-342-3p–mediated upregulation of GSNO reductase expression. Furthermore, our data demonstrate that this adverse effect can be overcome by supplementing its substrate, GSNO, or by inhibiting the enzyme itself. Rates of BPD have not improved over the past two decades; nor have new therapies been developed. GSNO-based therapies are a novel treatment of the respiratory problems that patients with BPD experience.

Management of Prematurity-Associated Wheeze and Its Association with Atopy

Introduction

Although preterm birth is associated with respiratory morbidity in childhood, the role of family history of atopy and whether appropriate treatment has been instituted is unclear. Thus we assessed (i) the prevalence of respiratory symptoms, particularly wheezing, in childhood; (ii) evaluated the role of family history of atopy and mode of delivery, and (iii) documented the drug usage, all in preterm-born children compared to term-born control children.

Methods

We conducted a cross-sectional population-based questionnaire study of 1–10 year-old preterm-born children (n = 13,361) and matched term-born controls (13,361). Data (n = 7,149) was analysed by gestational groups (24–32 weeks, 33–34 weeks, 35–36 weeks and 37–43 weeks) and by age, <5 years old or ≥ 5 years.

Main Results

Preterm born children aged <5 years (n = 2,111, term n = 1,402) had higher rates of wheeze-ever [odds ratio: 2.7 (95% confidence intervals 2.2, 3.3); 1.8 (1.5, 2.2); 1.5 (1.3, 1.8) respectively for the 24–32 weeks, 33–34 weeks, 35–36 weeks groups compared to term]. Similarly for the ≥5 year age group (n = 2,083, term n = 1,456) wheezing increased with increasing prematurity [odds ratios 3.3 (2.7, 4.1), 1.8 (1.5, 2.3) and 1.6 (1.3, 1.9) for the three preterm groups compared to term]. At both age groups, inhaler usage was greater in the lowest preterm group but prematurity-associated wheeze was independent of a family history of atopy.

Conclusions

Increasing prematurity was associated with increased respiratory symptoms, which were independent of a family history of atopy. Use of bronchodilators was also increased in the preterm groups but its efficacy needs careful evaluation.

Inflammatory activity at school age in very low birth weight bronchopulmonary dysplasia survivors

OBJECTIVE

Airway inflammation is involved in the pathogenesis of bronchopulmonary dysplasia (BPD). The aim of the study was to evaluate the inflammatory activity in plasma and exhaled air in very low birth weight (VLBW) BPD survivors at school age.

METHODS

Twenty-one 6-14-year-old former VLBW (birth weight ≤1,500 g) children with severe radiographic BPD (radBPD), 19 without radBPD (nonBPD group) and 19 non-asthmatic term controls underwent measurement of eosinophil cationic protein, IL-6, IL-8, adiponectin, adipsin, leptin, and resistin in plasma, leukotriene B4 and 8-isoprostane in exhaled breath condensate, and NO in exhaled breath. Background data were obtained from patient records, clinical examination and parental questionnaire. Both univariate and multivariate models were applied in the statistical analysis.

RESULTS

There were no significant differences between the groups in any of the inflammatory markers measured. Five (25%) radBPD and 2 (11%) nonBPD children reported asthma (P = 0.058). In logistic regression analysis, exposure to chorioamnionitis was associated with low IL-8 (OR 29.0, 95% CI 3.27-258) and postnatal corticosteroid therapy with high adiponectin (OR 32.0, 95% CI 1.29-793). High body mass index standard deviation score (BMI-SDS) was associated with high plasma adipsin (OR 2.47, 95% CI 1.07-5.75) and leptin (OR 5.76, 95%CI 1.83-18.2) levels.

CONCLUSIONS

The inflammatory activity seems to decrease by school age in VLBW BPD survivors. Chorioamnionitis and postnatal corticosteroid treatment may modulate the inflammatory responsiveness in VLBW subjects even up to school age. The respiratory outcome in VLBW infants might be improved by preventing excessive weight gain.

Very low birth weight and respiratory outcome: association between airway inflammation and hyperresponsiveness

BACKGROUND

The respiratory outcomes after preterm birth have changed, and it is unclear whether increased airway hyperresponsiveness (AHR) later in childhood is associated with airway inflammation.

OBJECTIVE

To investigate the association between AHR and fractional exhaled nitric oxide (FeNO), including the alveolar concentration of nitric oxide, in school-age children with very low birth weight (VLBW).

METHODS

Twenty-nine children with VLBW, 33 children with a history of early wheeze, and 60 healthy controls underwent a FeNO measurement and bronchial challenge test with histamine. Atopy was assessed with skin prick tests.

RESULTS

Children with VLBW had well-preserved baseline lung function but significantly increased AHR, expressed as the dose response slope (P < .001). Geometric mean FeNO levels were similar between VLBW children and healthy controls, and a history of bronchopulmonary dysplasia had no effect. In the VLBW and early wheeze groups, AHR was associated with FeNO (r = 0.47, P = .01, and r = 0.43, P = .013, respectively), but in a stratified analysis, this association was significant only in atopic individuals. By using the multiple flow FeNO technique, the bronchial nitric oxide flux rather than alveolar nitric oxide concentrations were associated with AHR in both children with early wheeze and VLBW.

CONCLUSION

We conclude that in VLBW children AHR is related to FeNO but only in atopic individuals. Similar to children with early wheeze, this association is dependent on bronchial flux rather than alveolar nitric oxide concentration. It is likely that AHR is modified by atopic inflammation rather than by inflammatory process due to prematurity.

Inflammatory markers in induced sputum of school children born before 32 completed weeks of gestation

OBJECTIVE

To test whether chronic bronchial inflammation may be a contributing risk factor for persistent airflow limitation in children born before 32 weeks of gestation in later life.

STUDY DESIGN

Thirty-six of 160 children born before 32 completed weeks of gestation who were born between 1988 and 1992 were recruited at a median age of 11 years. Eighteen age-matched children born at term were controls; 47% of the premature infants and 61% of the term born children produced sputum of sufficient quality for interleukin (IL)-8, cell numbers, and differential counts.

RESULTS

Compared with term born children, sputum from the premature group had a higher proportion of neutrophils (62% vs 3.8%; P < .001) and higher IL-8/protein values (1.93 μg/g vs 0.64 μg/g; P = .008). Forced expiratory flow 25%-75% and forced expiratory volume in 1 second/vital capacity were significantly lower (73.4 % vs 116% predicted, P = .002 and 97% vs 101%, P = .012, respectively). Lung function values and sputum indices did not correlate. IL-8/protein and neutrophil percentages correlated significantly with decreasing gestational age (Spearman rank coefficient = -0.58, P = .020 and -.70, P =.03 respectively).

CONCLUSION

A significant proportion of school children born very preterm demonstrate persistent peripheral airway obstruction that is accompanied by neutrophilic lower airway inflammation.

Late (≥ 7 days) inhalation corticosteroids to reduce bronchopulmonary dysplasia in preterm infants

BACKGROUND

Bronchopulmonary dysplasia (BPD), defined as oxygen dependence at 36 weeks postmenstrual age (PMA), remains an important complication of prematurity. Pulmonary inflammation plays a central role in the pathogenesis of BPD. Attenuating pulmonary inflammation with postnatal systemic corticosteroids reduces the incidence of BPD in preterm infants but may be associated with an increased risk of adverse neurodevelopmental outcomes. Local administration of corticosteroids via inhalation might be an effective and safe alternative.

OBJECTIVES

To determine if administration of inhalation corticosteroids after the first week of life to preterm infants at high risk of developing BPD is effective and safe in reducing the incidence of death and BPD as separate or combined outcomes.

SEARCH METHODS

We identified randomised, controlled trials by searching the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library), PubMed (from 1966), EMBASE (from 1974), CINAHL (from 1982), references from retrieved trials and handsearches of journals, all assessed to February 2012.

SELECTION CRITERIA

Randomised controlled trials comparing inhalation corticosteroids, started ≥ 7 days postnatal age (PNA) but before 36 weeks PMA, to placebo in ventilated and non-ventilated infants at risk of BPD were included. Trials investigating systemic corticosteroids versus inhalation corticosteroids were excluded.

DATA COLLECTION AND ANALYSIS

Data on patient characteristics, trial methodology, and inhalation regimens were collected. The primary outcomes were death or BPD, or both, at 28 days PNA or 36 weeks PMA. Secondary outcomes were short-term respiratory outcomes, such as failure to extubate, total days of mechanical ventilation and oxygen use, and the need for systemic corticosteroids. The original trialists were contacted to verify the validity of extracted data and to provide missing data. All data were analysed using RevMan 5.0.24. When possible, meta-analysis was performed using typical risk ratio (TRR) for dichotomous outcomes and weighted mean difference (WMD) for continuous outcomes along with their 95% confidence intervals (CI). Ventilated and non-ventilated participants were analysed separately.

MAIN RESULTS

Eight trials randomising 232 preterm infants were included in this review. Inhalation corticosteroids did not reduce the separate or combined outcomes of death or BPD. Furthermore, inhalation steroids did not impact short-term respiratory outcomes such as failure to extubate and total duration of mechanical ventilation or oxygen dependency. There was a trend to a reduced use of systemic corticosteroids in favour of inhalation corticosteroids (TRR 0.51; 95% CI 0.26 to 1.00). There was a paucity of data on short-term and long-term adverse effects. These results should be interpreted with caution because the total number of randomised patients is relatively small and most trials differed considerably in patient characteristics, inhalation therapy and outcome definitions.

AUTHORS' CONCLUSIONS

Based on the results of the currently available evidence, inhalation corticosteroids initiated at ≥ 7 days of life for preterm infants at high risk of developing BPD cannot be recommended at this point in time. More and larger randomised, placebo-controlled trials are needed to establish the efficacy and safety of inhalation corticosteroids.

Mechanisms of injury to the preterm lung and airway: implications for long-term pulmonary outcome

Despite changes in the epidemiology of bronchopulmonary dysplasia (BPD), longer-term morbidity, particularly in the form of airway dysfunction, remains a substantial problem in former preterm infants. The stage for this respiratory morbidity may begin as early as the transition from fetal to neonatal life. Newer therapeutic approaches for BPD should be directed toward minimizing this longer-term respiratory morbidity. Neonatal animal models focused primarily on hyperoxic exposure may provide important insights into the pathogenesis of longer-term airway hyperreactivity in this population.

WITHDRAWN. Inhaled steroids for neonatal chronic lung disease

BACKGROUND

Bronchopulmonary dysplasia (BPD) is a chronic disorder associated with prematurity. Systemic steroids induce at least a temporary improvement in respiratory function, but are associated with adverse side effects. Inhaled steroids have fewer side effects.

OBJECTIVES

To determine if inhaled corticosteroids are effective in alleviating the morbidity of bronchopulmonary dysplasia (BPD) compared to placebo.

SEARCH STRATEGY

We identified randomised, controlled trials (RCT) within the Cochrane Database, references from retrieved trials, hand searches of journals and contact with pharmaceutical companies and experts in this field.

SELECTION CRITERIA

Only randomised controlled trials involving infants with chronic lung disease of prematurity and treated with inhaled steroids versus placebo were included. Patients receiving systemic corticosteroids were excluded. Co-interventions included antenatal systemic steroids, routine neonatal intensive care, ventilatory support, surfactant replacement therapy, diuretics and bronchodilators.

DATA COLLECTION AND ANALYSIS

Four of the seven included trials were of good methodological quality. There were five parallel-group trials in ventilated infants. These were comparable in terms of population, co-interventions and need for increased inspired oxygen concentration. They differed in terms of type, dose and duration (7-28 days) of inhaled steroids. Two cross-over trials were performed in non-ventilated patients. An update search was conducted in June 2002, which identified an additional excluded study.

MAIN RESULTS

The inability to extubate during treatment was markedly reduced in infants treated with inhaled steroids; Peto Odds Ratio (OR) 0.12, 95% Confidence Interval (CI) 0.03 to 0.43. There was heterogeneity in this finding, however, with one study that contributed 30% of the total number of patients reporting no successful extubations in either treatment arm over one week. The risk of sepsis appeared similar between the two groups (N=3, OR=0.72, 95%CI: 0.21 to 2.43). The small number of trials precluded analysis to examine the effect of differences in drug, duration of therapy, delivery system, co-interventions, and disease severity. Reduced oxygen requirements were reported in one of the two trials performed in non-ventilated infants, but inadequate data reporting precluded pooling of data.

AUTHORS' CONCLUSIONS

In ventilated infants with BPD, inhaled steroids administered for 1 to 4 weeks improved the rate of extubation with no apparent increase in the risk of sepsis. No firm conclusion could be derived with regard to the efficacy of inhaled steroids in non-ventilated infants.

[Bronchopulmonary dysplasia and prematurity. Short-and long-term respiratory changes]

Bronchopulmonary dysplasia (BPD) is the most frequent chronic lung disease in premature children. With the inclusion of antenatal steroid therapy, surfactant use and novel mechanical ventilation strategies, survival of premature newborns has increased, whereupon the incidence of BPD has not only decreased but has also risen in extremely premature newborns. This has led to a high respiratory morbidity in the first 2-3 years of life, with numerous admissions to hospital and respiratory exacerbations mostly due to viral infections. Although there is a trend towards improvement, during school age and adolescence, respiratory symptoms may persist, due to changes in pulmonary function often showing a lower exercise capacity. Although BPD symptoms are similar to those of asthma, as there is limitation in airflow and bronchial hyperresponsiveness (BHR), pathophysiological mechanisms could be different in both diseases. On the other hand, isolated prematurity plays an important role in the child's respiratory pathology, proving that pulmonary function alterations in preterm children are present since the first months of life. A higher respiratory morbidity has also been observed in these children when compared to full-term newborns, not only during the first years of life but also subsequently. In this study, different aspects of chronic respiratory disease associated with prematurity will be analysed, drawing special attention to clinical symptoms, respiratory function changes, BHR and exercise capacity. All these aspects will be reviewed from early childhood until adolescence and young adult age. Similarities and differences between BPD and asthma will also be discussed.

Characteristics of asthma and airway hyper-responsiveness after premature birth

Asthma-like symptoms and airway hyper-responsiveness (AHR) are frequently reported in children subsequent to premature birth and bronchopulmonary dysplasia (BPD). There is limited knowledge on the mechanisms underlying these respiratory manifestations. Generally, childhood asthma and AHR is described within a context of inheritance, allergy and eosinophilic airway inflammation, and often in relation to cigarette exposures. We investigated these factors in relation to current asthma and AHR in a population-based cohort of 81 young people, born with gestational age < or = 28 wk or birth weight < or = 1000 g, and in a matched term-born control population. In the pre-term population, asthma and AHR were additionally studied in relation to neonatal respiratory morbidity. At follow up, more pre-term than control subjects had asthma. Forced expiratory volume in first second (FEV1) was reduced, AHR was substantially increased, and the level of the urinary leukotriene metabolite E4 (U-LTE4) was increased in the pre-term population compared to the term-born. In control subjects, asthma and AHR was associated with a pattern consistent with inheritance, allergy, airway inflammation, and cigarette exposures. In the pre-terms, asthma and AHR was either unrelated or less related to these factors. Instead, AHR was strongly related to a neonatal history of BPD and prolonged requirement for oxygen treatment. In conclusion, asthma and AHR subsequent to extremely premature birth differed from typical childhood asthma with respect to important features, and AHR was best explained by neonatal variables. These respiratory manifestations thus seem to represent a separate clinical entity.

Inhaled steroids for neonatal chronic lung disease

BACKGROUND

Bronchopulmonary dysplasia (BPD) is a chronic disorder associated with prematurity. Systemic steroids induce at least a temporary improvement in respiratory function, but are associated with adverse side effects. Inhaled steroids have fewer side effects.

OBJECTIVES

To determine if inhaled corticosteroids are effective in alleviating the morbidity of bronchopulmonary dysplasia (BPD) compared to 0-placebo.

SEARCH STRATEGY

We identified randomised, controlled trials (RCT) within the Cochrane Database, references from retrieved trials, hand searches of journals and contact with pharmaceutical companies and experts in this field.

SELECTION CRITERIA

Only randomised controlled trials involving infants with chronic lung disease of prematurity and treated with inhaled steroids versus placebo were included. Patients receiving systemic corticosteroids were excluded. Co-interventions included antenatal systemic steroids, routine neonatal intensive care, ventilatory support, surfactant replacement therapy, diuretics and bronchodilators.

DATA COLLECTION AND ANALYSIS

Four of the seven included trials were of good methodological quality. There were five parallel-group trials in ventilated infants. These were comparable in terms of population, co-interventions and need for increased inspired oxygen concentration. They differed in terms of type, dose and duration (7-28 days) of inhaled steroids. Two cross-over trials were performed in non-ventilated patients.

MAIN RESULTS

The inability to extubate during treatment was markedly reduced in infants treated with inhaled steroids; Peto Odds Ratio (OR) 0.12, 95% Confidence Interval (CI) 0.03 to 0.43. There was heterogeneity in this finding, however, with one study that contributed 30% of the total number of patients reporting no successful extubations in either treatment arm over one week. The risk of sepsis appeared similar between the two groups (N=3, OR=0.72, 95%CI: 0.21 to 2.43). The small number of trials precluded analysis to examine the effect of differences in drug, duration of therapy, delivery system, co-interventions, and disease severity. Reduced oxygen requirements were reported in one of the two trials performed in non-ventilated infants, but inadequate data reporting precluded pooling of data.

REVIEWER'S CONCLUSIONS

In ventilated infants with BPD, inhaled steroids administered for 1 to 4 weeks improved the rate of extubation with no apparent increase in the risk of sepsis. No firm conclusion could be derived with regard to the efficacy of inhaled steroids in non-ventilated infants.