Increasing airway obstruction through life following bronchopulmonary dysplasia: a meta-analysis

Research priorities for preterm lung health research across the lifespan: a community priority setting partnership

BACKGROUND

It is essential to embed patient and public perspectives into every stage of the research journey, including setting the future research agenda. The substantial gaps in our understanding of prematurity-associated lung disease presented a timely opportunity to determine the community's research priorities.

OBJECTIVE

To conduct a priority setting partnership (PSP) to determine the top 10 research priorities for preterm lung health.

DESIGN

We undertook a modified James Lind Alliance methodology comprising three main stages: (1) an idea generating survey with open questions to ascertain the community's most important ideas for future preterm lung health research, (2) prioritisation survey to distill the main themes into a shortlist of 20 and (3) consensus workshop where participants were tasked with ranking their final top 10. This PSP is reflective of the view of preterm-born individuals, parents of preterm children and healthcare professionals in an Australian healthcare setting.

RESULTS

We collated 144 submissions from the idea generating survey from which 27 prioritisation themes were developed. From the 150 prioritisation survey responses, the 20 themes receiving the most votes were taken to the consensus workshop. Participants identified the following top 10: (1) lifelong impacts; (2) interventions, treatments or supports; (3) ongoing lung health follow-up; (4) diagnostic tools, resources and education for primary healthcare providers; (5) resources to inform and empower families; (6) relationship to physical health and developmental issues; (7) preventing and/or treating lung infections; (8) additional supports, resources and research for minority groups; (9) impact on mental well-being; and (10) likelihood of asthma diagnosis.

CONCLUSION

Priorities identified through the PSP will be invaluable in informing future research into prematurity-associated lung disease.

Respiratory support and bronchopulmonary dysplasia in infants born at 22-26 weeks gestation in Sweden, 2004-2007 and 2014-2016

BACKGROUND

Our aim was to evaluate if increased survival and new ventilation strategies were accompanied by a changed incidence of bronchopulmonary dysplasia (BPD) in Sweden over a decade.

METHODS

Data from two Swedish population-based studies of live-born infants with gestational age (GA) 22-26 weeks, born during 2004-2007 (n=702) and 2014-2016 (n=885), were compared for survival, any BPD, moderate BPD and severe BPD and the composite outcomes of any BPD or death and severe BPD or death at 36 weeks postmenstrual age (PMA). Ventilation strategies and interventions were analysed. Any BPD was defined as the use of supplemental oxygen or any respiratory support at 36 weeks PMA, moderate BPD as nasal cannula with <30% oxygen and severe BPD as ≥30% oxygen, continuous positive airway pressure (CPAP) or mechanical ventilation.

RESULTS

Survival to 36 weeks PMA increased from 72% to 81% (p<0.001). Total days on mechanical ventilation increased from a median of 9 to 16 days (p<0.001). High-flow nasal cannula (HFNC) was introduced between the cohorts, and days of CPAP and HFNC increased from 44 to 50 days (p<0.001). Any BPD was unchanged at 65% versus 68%. Moderate BPD increased from 37% to 47% (p=0.003), while the incidence of severe BPD decreased from 28% to 23% (p<0.046). Severe BPD or death decreased from 48% to 37% (p<0.001), while any BPD or death remained unchanged at 74% versus 75%.

CONCLUSION

Even though an increased survival of infants born at 22-26 weeks GA was accompanied by an increased duration of invasive and non-invasive respiratory support, the incidence of any BPD remained unchanged, while severe BPD decreased in infants alive at 36 weeks PMA.

Perception of quality of life in school-age children born before 32 weeks of gestational age

Preterm infants with bronchopulmonary dysplasia (BPD) are at increased risk of disruptions in their quality of life (QoL) at school age, often associated with respiratory morbidity and the need for ongoing hospital care. The objective of this study is to assess the impact of BPD on the perceived quality of life in preterm infants at school age. We conducted a prospective observational study of infants born at less than 32 weeks gestation who were admitted to our neonatal unit between January 2012 and December 2014. These children were followed up, and at ages 8 to 10 years, their quality of life was assessed using the Pediatric Quality of Life (PedsQL) questionnaire, with higher scores indicating poorer quality of life. The study included 102 patients with a mean gestational age of 29.42 weeks (SD 1.87) and a mean birth weight of 1221.36 g (SD 347.25), with an average age of 8.59 years (SD 0.90) at the time of the survey. Patients with BPD 2-3 exhibited a significantly poorer perception of "total quality of life" (p = 0.03) and in the "social activities" domain (p = 0.02) compared to those without BPD or with BPD 1, even after adjusting for gestational age in a multivariate model. No significant differences were observed for the "health and activities" domain (p = 0.31), "emotional state" domain (p = 0.58), or "school activities" domain (p = 0.33). Patients who experienced asthma symptoms during follow-up had a poorer perception of total quality of life than those who did not (20.53 (SD 6.19) vs. 11.89 (SD 1.44), p < 0.01). No significant differences were found between patients without a diagnosis of BPD and those with grade 1 BPD. Similarly, no significant differences were observed when comparing patients of less than 28 weeks gestational age and more than 28 weeks of gestational age.

CONCLUSION

In our population of preterm school-aged children with grades 2-3 BPD, worse perceived quality of life was reported compared to those with no BPD or grade 1 BPD. Preterm children who developed asthma symptoms during the follow-up period also reported lower perceived quality of life. No differences in QoL were observed between patients with no BPD and those with grade 1 BPD, or between those born before and after 28 weeks of gestation. These findings highlight the importance of assessing the QoL in preterm patients with BPD, particularly those with grade 2-3 BPD or asthma symptoms, as early assessment can help identify patients who may benefit from targeted interventions to improve quality of life and long-term outcomes.

WHAT IS KNOWN

• Survival rates of extremely preterm infants have increased significantly in recent years, but respiratory morbidity, particularly bronchopulmonary dysplasia, remains a common problem. The impact of BPD on the quality of life of preterm infants, particularly at school age, is still debated. BPD is associated with an increased risk of asthma and abnormal lung function, but its effect on QoL is not fully understood.

WHAT IS NEW

• Preterm infants with grade 2-3 BPD have a significantly worse perception of QoL at school age, especially in the domain of "social activities". This finding emphasises the need for long-term follow-up and possible interventions to improve QoL, especially in terms of social integration. Asthma symptoms during childhood also contribute to poorer QoL perceptions, highlighting the importance of early diagnosis and effective treatment.

Pulmonary function and bronchopulmonary dysplasia classification: insights from the Spanish Registry

In 2016, the Spanish Research Group on Bronchopulmonary Dysplasia (BPD) (GEIDIS) established a national registry with participation of 66 hospitals to collect information on clinical characteristics and long-term outcomes of BPD infants into adulthood. The aim of this observational study is to examine forced spirometry data in early childhood and to assess their correlation with the respiratory support required at 36 weeks postmenstrual age (PMA). The study analyzed data from preterm infants with BPD born between January 2016 and December 2017 who underwent forced spirometry at 5-7 years of age. Statistical analyses were conducted to investigate the relationships between spirometry results, perinatal factors, and the required respiratory support at 36 weeks PMA. The study involved 143 patients with a median gestational age (GA) of 27.3 weeks (range 25.7-28.7) and a median weight of 880 g (range 740-1135). Abnormal spirometry results were observed in 39.2% (56) of the patients. Among patients diagnosed with BPD type 3, those requiring over 30% oxygen at 36 weeks PMA exhibited an increased risk of abnormal spirometry results (OR 4.48; 95% CI 1.11-18.13) compared to those requiring positive pressure with less than 30% oxygen. In addition, this subgroup had a higher risk of developing a restrictive-mixed pattern compared to those with BPD type 1 (OR 10.65; 95% CI 2.06-54.98) and BPD type 2 (OR 6.76; 95% CI 1.09-42.06). No significant differences were found in the incidence of an obstructive pattern between BPD types.      Conclusion: The requirement of more than 30% oxygen at 36 weeks PMA serves as a risk indicator for pulmonary function impairment in school-aged children with BPD. These findings suggest persistent airway and parenchymal injury in this specific patient population, and highlight the importance of careful monitoring to evaluate their long-term effects on lung function. What is Known: • Premature patients with bronchopulmonary dysplasia (BPD) may present abnormalities in pulmonary function tests during school age. However, the predictive accuracy of consensus BPD severity classification remains uncertain. What is New: • The requirement of more than 30% oxygen at 36 weeks postmenstrual age (PMA) indicates a potential risk of pulmonary function impairment in school-aged children with BPD. Additionally, a significant correlation has been observed between a restrictive-mixed pattern with exposure to mechanical ventilation and the development of severe forms of BPD.

The respiratory consequences of preterm birth: from infancy to adulthood

Survival of preterm-born infants, especially at extremes of prematurity (less than 28 weeks gestation), is now common, particularly in the developed world. Despite advances in neonatal care, short-term respiratory morbidity, termed bronchopulmonary dysplasia (also called chronic lung disease of prematurity), remains an important clinical outcome. As survival during the neonatal period has improved, preterm-born individuals are now entering childhood, adolescence and adulthood in far greater numbers, and adverse longer-term respiratory outcomes following birth at an immature stage of lung development are becoming increasingly apparent. In this article, we shall review the background of the major respiratory complications in the neonatal period, bronchopulmonary dysplasia, and the current evidence regarding its prevention and management. In addition, we shall review the emerging literature on the respiratory morbidity experienced in childhood, adolescence, and adulthood by preterm-born survivors, with reduced lung function and a risk of developing chronic obstructive pulmonary disease in early adult life. As this population of preterm-born individuals increases, an understanding of the respiratory consequences of preterm birth will become increasingly important not only for neonatologists, paediatricians and paediatric pulmonologists but also for physicians and healthcare professionals involved in the care of adults who were born preterm.

Changes in Lung Function Among Infants Born Extremely Preterm over a 20-Year Period in the Post-Surfactant Era: A Retrospective Study

Lung function was assessed at 8 years in 308 infants born extremely preterm between 1994 and 2013. Although lung function of those infants born at 22 through 25 weeks remained unchanged, those who were born at 26-27 weeks showed a significant improvement over the past 2 decades.

Expiratory airflow limitation in adults born extremely preterm: A systematic review and meta-analysis

Extreme preterm (EP) birth, denoting delivery before the onset of the third trimester, interrupts intrauterine development and causes significant early-life pulmonary trauma, thereby posing a lifelong risk to respiratory health. We conducted a systematic review and meta-analysis to investigate adult lung function following EP birth (gestational age <28 weeks); comparing forced expiratory volume in first second (FEV1), forced vital capacity (FVC), and FEV1/FVC to reference values. Subgroup differences were explored based on timing of birth relative to surfactant use (1991) and bronchopulmonary dysplasia (BPD) status. Systematic searches were performed in Medline, EMBASE, Web of Science and Cochrane Central. Quality assessments were carried out using a modified Newcastle-Ottawa Scale for cohort studies. Sixteen studies encompassing 1036 EP-born adults were included, with 14 studies (n = 787) reporting data as %predicted, and 11 (n = 879) as z-score (not mutually exclusive). Overall mean [95 % confidence interval (CI)] %FEV1 was 85.30 (82.51; 88.09), %FVC was 94.33 (91.74; 96.91), and FEV1/FVC was 79.54 (77.71 to 81.38), all three with high heterogeneity. Overall mean (95 %CI) zFEV1 was -1.05 (-1.21; -0.90) and zFVC was. -0.45 (-0.59; -0.31), both with moderate heterogeneity. Subgroup analyses revealed no difference in FEV1 before versus after widespread use of surfactant, but more impairments after neonatal BPD. This meta-analysis revealed significant airflow limitation in EP-born adults, mostly explained by those with neonatal BPD. FEV1 was more reduced than FVC, and FEV1/FVC was at the lower limit of normal. Although at a group level, most adult EP-born individuals do not meet COPD criteria, these findings are concerning.

Long-term pulmonary outcomes in BPD throughout the life-course

Respiratory disease is one of the most common complications of preterm birth. Survivors of prematurity have increased risks of morbidities and mortalities independent of prematurity, and frequently require multiple medications, home respiratory support, and subspecialty care to maintain health. Although advances in neonatal and pulmonary care have improved overall survival, earlier gestational age, lower birth weight, chorioamnionitis and late onset sepsis continue to be major factors in the development of bronchopulmonary dysplasia. These early life events associated with prematurity can have respiratory consequences that persist into adulthood. Furthermore, after initial hospital discharge, air pollution, respiratory tract infections and socioeconomic status may modify lung growth trajectories and influence respiratory outcomes in later life. Given that the incidence of respiratory disease associated with prematurity remains stable or increased, there is a need for pediatric and adult providers to be familiar with the natural history, manifestations, and common complications of disease.

Unravelling the respiratory health path across the lifespan for survivors of preterm birth

Many survivors of preterm birth will have abnormal lung development, reduced peak lung function and, potentially, an increased rate of physiological lung function decline, each of which places them at increased risk of chronic obstructive pulmonary disease across the lifespan. Current rates of preterm birth indicate that by the year 2040, around 50 years since the introduction of surfactant therapy, more than 700 million individuals will have been born prematurely-a number that will continue to increase by about 15 million annually. In this Personal View, we describe current understanding of the impact of preterm birth on lung function through the life course, with the aim of putting this emerging health crisis on the radar for the respiratory community. We detail the potential underlying mechanisms of prematurity-associated lung disease and review current approaches to prevention and management. Furthermore, we propose a novel way of considering lung disease after preterm birth, using a multidimensional model to determine individual phenotypes of lung disease-a first step towards optimising management approaches for prematurity-associated lung disease.