Bronchial hyper-responsiveness in preterm-born subjects: A systematic review and meta-analysis

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.

Effects of size at birth on health, growth and developmental outcomes in children up to age 18: an umbrella review

BACKGROUND

Size at birth, an indicator of intrauterine growth, has been studied extensively in relation to subsequent health, growth and developmental outcomes. Our umbrella review synthesises evidence from systematic reviews and meta-analyses on the effects of size at birth on subsequent health, growth and development in children and adolescents up to age 18, and identifies gaps.

METHODS

We searched five databases from inception to mid-July 2021 to identify eligible systematic reviews and meta-analyses. For each meta-analysis, we extracted data on the exposures and outcomes measured and the strength of the association.

FINDINGS

We screened 16 641 articles and identified 302 systematic reviews. The literature operationalised size at birth (birth weight and/or gestation) in 12 ways. There were 1041 meta-analyses of associations between size at birth and 67 outcomes. Thirteen outcomes had no meta-analysis.Small size at birth was examined for 50 outcomes and was associated with over half of these (32 of 50); continuous/post-term/large size at birth was examined for 35 outcomes and was consistently associated with 11 of the 35 outcomes. Seventy-three meta-analyses (in 11 reviews) compared risks by size for gestational age (GA), stratified by preterm and term. Prematurity mechanisms were the key aetiologies linked to mortality and cognitive development, while intrauterine growth restriction (IUGR), manifesting as small for GA, was primarily linked to underweight and stunting.

INTERPRETATION

Future reviews should use methodologically sound comparators to further understand aetiological mechanisms linking IUGR and prematurity to subsequent outcomes. Future research should focus on understudied exposures (large size at birth and size at birth stratified by gestation), gaps in outcomes (specifically those without reviews or meta-analysis and stratified by age group of children) and neglected populations.

PROSPERO REGISTRATION NUMBER

CRD42021268843.

Pulmonary phenotypes of bronchopulmonary dysplasia in the preterm infant

Bronchopulmonary dysplasia (BPD) remains the most common complication of premature birth, imposing a significant and potentially life-long burden on patients and their families. Despite advances in our understanding of the mechanisms that contribute to patterns of lung injury and dysfunctional repair, current therapeutic strategies remain non-specific with limited success. Contemporary definitions of BPD continue to rely on clinician prescribed respiratory support requirements at specific time points. While these criteria may be helpful in broadly identifying infants at higher risk of adverse outcomes, they do not offer any precise information regarding the degree to which each compartment of the lung is affected. In this review we will outline the different pulmonary phenotypes of BPD and discuss important features in the pathogenesis, clinical presentation, and management of these frequently overlapping scenarios.

Pharmacotherapy of BPD: Current status & future perspectives

Bronchopulmonary dysplasia (BPD) is a disease exclusive to prematurity and has changed in its definition since Northway first described it in 1967. There have been countless clinical trials evaluating the efficacy of drugs in the treatment and prevention of BPD in human subjects, and an even larger number of animal studies. Despite these, only a handful of drugs are used at the bedside today, primarily due to the lack of consistent efficacy seen in clinical trials or due to reports of adverse effects. This review summarizes the list of the most commonly used drugs and emerging new therapies which target BPD and BPD-related pulmonary hypertension (BPD-PH), including those which have shown promise in human trials but are not yet used routinely.

Small vulnerable newborns-big potential for impact

Despite major achievements in child survival, the burden of neonatal mortality has remained high and even increased in some countries since 1990. Currently, most neonatal deaths are attributable to being born preterm, small for gestational age (SGA), or with low birthweight (LBW). Besides neonatal mortality, these conditions are associated with stillbirth and multiple morbidities, with short-term and long-term adverse consequences for the newborn, their families, and society, resulting in a major loss of human capital. Prevention of preterm birth, SGA, and LBW is thus critical for global child health and broader societal development. Progress has, however, been slow, largely because of the global community's failure to agree on the definition and magnitude of newborn vulnerability and best ways to address it, to frame the problem attractively, and to build a broad coalition of actors and a suitable governance structure to implement a change. We propose a new definition and a conceptual framework, bringing preterm birth, SGA, and LBW together under a broader umbrella term of the small vulnerable newborn (SVN). Adoption of the framework and the unified definition can facilitate improved problem definition and improved programming for SVN prevention. Interventions aiming at SVN prevention would result in a healthier start for live-born infants, while also reducing the number of stillbirths, improving maternal health, and contributing to a positive economic and social development in the society.

Lung function at 16-19 years in males and females born very prematurely

OBJECTIVES

To determine if there were differences in lung function at 16-19 years of age between males and females born very prematurely.

WORKING HYPOTHESIS

Females compared with males would have superior lung function and exercise capacity.

STUDY DESIGN

Cohort study.

PATIENT-SUBJECT SELECTION

Those born at less than 29 weeks of gestational age.

METHODOLOGY

Lung function testing (spirometry, oscillometry, diffusion capacity, lung clearance index, and plethysmography), a shuttle sprint test for exercise capacity, and a respiratory symptoms questionnaire.

RESULTS

Amongst 150 participants, males had poorer lung function compared with females with mean z score differences (95% CI [confidence interval]) after adjustment: forced expiratory flow at 75% (FEF₇₅ ) (-0.60 [-0.97,-0.24]), forced expiratory flow at 50% (FEF₅₀ ) (-0.39 [-0.72,-0.07]), forced expiratory flow at 25%-75% (FEF_25-75 ) (-0.62 [-0.98,-0.26]), the ratio of the forced expiratory volume in the first one second to the forced vital capacity of the lungs (FEV₁ :FVC ratio) (-0.71 [-1.09,-0.34]), diffusing capacity of the lungs for carbon monoxide (DLCO) (-0.41 [-0.78,-0.03]), diffusing capacity of the lung for carbon monoxide divided by alveolar volume (DLCO/VA) (-0.57 [-0.86,-0.28]). Exercise capacity and self-reported exercise were both significantly better in males than females (46% males achieving between 1250 and 1500 m shuttle sprint distance vs. 4.8% females) and 74% males versus 67% females undertaking some exercise. There were no significant differences by sex in the prevalence of either wheeze or current asthma.

CONCLUSIONS

Males had poorer lung function than females at age 16-19 years, but their exercise capacity was superior to females.

Prevalence of asthma in preterm and associated risk factors based on prescription data from the Korean National Health Insurance database

We retrospectively analyzed National Health Insurance claims data (January 2002-December 2018) to determine the asthma prevalence and risk factors among preterm infants born in Korea. Patients with asthma were defined as those with a history of asthma medication prescriptions at least twice per year with International Classification of Diseases, Tenth Edition codes J45 and J46. We enrolled 99,139 preterm infants. The prevalence of asthma among preterm and term infants was 32.7% and 26.9%, 21.2% and 19.1%, 6.7% and 5.9%, 2.0%, and 1.6%, and 2.4% and 1.6% at 2, 5, 10, 15, and 16 years of age, respectively. The relative risk (RR) of asthma in preterm infants was 1.1-fold that in female preterm infants. The RR of asthma medication prescriptions for infants with extreme prematurity was 1.92-fold that of infants with moderate/late pre-term status. Among preterm with bronchopulmonary dysplasia (BPD) and respiratory distress syndrome (RDS) without comorbidities, the RRs for the number of asthma medication prescriptions were 1.34 and 1.06, respectively. This study revealed a higher prevalence of asthma among preterm infants than that in term infants. Male sex, extreme prematurity, BPD, and RDS were identified as risk factors for asthma medication prescriptions in preterm infants.

Respiratory morbidity in preschool and school-age children born very preterm and its association with parents' health-related quality of life and family functioning

The purpose of this study is to describe the prevalence and severity of respiratory symptoms in children born very preterm and to assess their association with parents' health-related quality of life (HRQoL) and family functioning. We conducted a cross-sectional study and recruited children born less than 32 weeks' gestation between January 2006 and December 2019, in the greater Zurich area, Switzerland. Between May and December 2021, parents were invited to complete an online survey for their preterm child and for a control term born (≥ 37 weeks' gestation) sibling aged 1 to 18 years. We used a validated questionnaire to assess respiratory symptoms and the Pediatrics Quality of Life Family Impact Module (PedsQL FIM) to assess parents' HRQoL and family functioning. The survey was completed for 616 very preterm children (99 with bronchopulmonary dysplasia (BPD)) and 180 controls. Girls made up 45% (46% in controls) of the sample, and 63% (60% in controls) of participants were aged 6 to 18 years (school-age). Very preterm children reported a higher risk of respiratory symptoms than controls, especially preschoolers and those with moderate-to-severe BPD. Parents of children with "mild" and "moderate-severe" respiratory symptoms had on average -3.9 (95%CI: -6.6 to -1.1) and -8.2 (-11.2 to -5.2) lower PedsQL FIM total score, respectively, than parents of children with no symptoms. The same pattern was observed after stratifying by age categories.  Conclusions: Our study suggests that respiratory morbidity in very preterm children has a negative impact on parents' HRQoL and family functioning, even beyond the first years of life. What is Known: • The burden of respiratory morbidity associated with very premature birth is high and last far beyond the neonatal period. • Respiratory morbidity contributes to lower health-related quality of life (HRQoL) in parents of very preterm children in early infancy. What is New: • Respiratory morbidity in very preterm children has a negative impact on parents' HRQoL and family functioning beyond the first years of life. • Parents of very preterm children with moderate and severe respiratory symptoms are the ones who report lower scores, both for preschool and school-age children.

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.

Diagnosis and management of asthma in infants and preschoolers

Asthma is one of the most common chronic disease affecting children, and it often starts in infancy and preschool years. In previous birth cohorts, frequent wheezing in early life was associated with the development of asthma in later childhood and reduced lung function persisting into adulthood. Preschool wheezing is considered an umbrella term for distinctive diseases with different clinical features (phenotypes), each of which may be related to different underlying pathophysiologic mechanisms (endotypes). The classification of phenotypes of early wheezing is needed to identify children at high risk for developing asthma later who might benefit from early intervention. However, diagnosis of asthma in infants and preschoolers is particularly difficult because objective lung function tests cannot be performed and definitive biomarkers are lacking. Moreover, management of early asthma is challenging because of its different phenotypic presentations. Many prediction models and asthma guidelines have been developed to provide useful information for physicians to assess young children with recurrent wheezing and manage them appropriately. Many recent studies have investigated the application of personalized medicine for early asthma by identifying specific phenotypes and biomarkers. Further researches, including genetic and molecular studies, are needed to establish a clear definition of asthma and develop more targeted therapeutic approaches in this age group.

Pre- and Postnatal Vitamin D Status and Allergy Outcomes in Early Childhood

The dramatic increase in the prevalence of allergic disease in recent decades reflects environmental and behavioural changes that have altered patterns of early immune development. The very early onset of allergic diseases points to the specific vulnerability of the developing immune system to environmental changes and the development of primary intervention strategies is crucial to address this unparalleled burden. Vitamin D is known to have immunomodulatory functions. While allergic disease is multifactorial, associations with reduced sunlight exposure have led to the hypothesis that suboptimal vitamin D levels during critical early periods may be one possible explanation. Interventions to improve vitamin D status, especially in early life, may be the key to allergic disease prevention.

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.

Recommendations to optimize life-long health and wellbeing for people born preterm

The preterm birth rate in the United States is 10%, with 8% being born between 36 and 32 weeks of gestation, and the remaining 2% born less than 31 weeks of gestation. The global preterm birth rate varies from 5% to 18%, with varying survival rates. These percentages signify a population of people that will receive health care across the life course without ever being asked about a preterm birth history. With a steady rise in the survival rate of preterm infants being discharged home from the neonatal intensive care unit, with limited referrals for neonatal or developmental follow up, it is essential adult care providers ask the right questions and identify risk factors for this vulnerable population. This review describes the recently published, evidence-based recommendations for addressing preterm history across the life course. A robust review of the literature has demonstrated that the long-term sequelae of being born preterm can adversely affect health and quality of life. The following will offer preterm birth history recommendations based on assessment and diagnosis, prevention and management and referral and treatment. The goal of the recommendations is to create awareness among adult health providers in acknowledging a past medical history of preterm birth and providing appropriate preventive care, therefore shifting the paradigm of care from reactive intervention to proactive care.

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.

Development and verification of a risk prediction model for bronchopulmonary dysplasia in very low birth weight infants

BACKGROUND

To analyze the risk factors of bronchopulmonary dysplasia (BPD) of very low birth weight infants (VLBWIs), and to develop and verify a risk prediction model of BPD.

METHODS

The data of 611 VLBWIs from the neonatal intensive care unit (NICU) of a tertiary grade A hospital in Suzhou from January 2017 to September 2019 were collected. The data was randomly divided into the modeling set (451 cases) and the validation set (160 cases). Binary logistic regression was used to analyze the data, and the model was examined by a receiver operating characteristic (ROC) curve. The grouped data was used to verify the sensitivity and specificity of the model.

RESULTS

The study found that neonatal asphyxia, the positive rate of sputum culture, neonatal sepsis, neonatal respiratory distress syndrome (NRDS), blood transfusions (≥3), patent ductus arteriosus (PDA), the time of invasive mechanical ventilation, the duration of oxygen therapy, and the time of parenteral nutrition were the independent risk factors of BPD, while 1 min Apgar score was a protective factor. The model formula was Z=neonatal asphyxia * 1.229 + the positive rate of sputum culture * 1.265 + neonatal sepsis * 1.677 + NRDS * 1.848 + blood transfusions (≥3) * 1.455 + PDA * 1.835 - 1 min Apgar score * 0.25 + the time of invasive mechanical ventilation * 0.123 + the duration of oxygen therapy * 0.09 + the time of parenteral nutrition * 0.057 - 8.077. The area under the ROC curve of this model was 0.965 (95% CI: 0.946-0.983), with a sensitivity of 93.7% and a specificity of 91.3%. Verification of this prediction model showed a sensitivity of 92.9% and a specificity of 76%, demonstrating that the effects of this model were satisfactory.

CONCLUSIONS

The risk prediction model had a good predictive effect for the risk of BPD in VLBWIs, and can provide a reference for preventive treatment and nursing intervention.

The lower respiratory airway wall in children in health and disease

Alone or in association with other lung or thorax component disorders, the airway wall (AWW) remains one of the most frequently involved elements in paediatric lung diseases. A myriad of AWW disorders will present with similar symptomatology. It is thus important for the clinician to reappraise the normal development and structure of the AWW to better understand the underlying disease patterns. We herein provide an overview of the structure of the AWW and a description of its development from the fetal period to adulthood. We also detail the most common AWW changes observed in several acute and chronic respiratory disorders as well as after cigarette smoke or chronic pollution exposure. We then describe the relationship between the AWW structure and lung function. In addition, we present the different ways of investigating the AWW structure, from biopsies and histological analyses to the most recent noninvasive airway (AW) imaging techniques. Understanding the pathophysiological processes involved in an individual patient will lead to the judicious choice of nonspecific or specific personalised treatments, in order to prevent irreversible AW damage.

Respiratory morbidity in very low birth weight infants through childhood and adolescence

OBJECTIVE

To describe the long-term (up to 18 years of age) respiratory outcomes of children and adolescents born at very low birth weight (VLBW; ≤1500 g) in comparison with that of children born >1500 g.

METHODS

An observational, longitudinal, retrospective study comparing VLBW infants with matched controls, registered at a large health maintenance organization in Israel. Pulmonary outcomes collected anonymously from the electronic medical files included respiratory illness diagnoses, purchased medications for respiratory problems, office visits with either a pediatric pulmonologist or cardiologist and composite respiratory morbidity combining all these parameters.

RESULTS

Our study included 5793 VLBW infants and 11,590 matched controls born between 1998 and 2012. The majority (99%) of VLBW infants were premature (born < 37 weeks' gestation), while 93% of controls were born at term. The composite respiratory morbidity was significantly higher in VLBW infants compared with controls in all age groups (relative risk [95% confidence interval]: 1 year: 1.22 [1.19-1.26], <2 years: 1.30 [1.27-1.34], 2-6 years: 1.29 [1.27-1.32], 6-12 years: 1.53 [1.47-1.59], 12-18 years: 1.46 [1.35-1.56]; respectively). Both VLBW infants and controls demonstrated a steady decline in the composite respiratory morbidity with aging. In VLBW infants, lower gestational age was associated with higher respiratory morbidity only until 2 years of age and the morbidity declined in each gestational age group until adolescence.

CONCLUSION

Our study confirmed a strong association between VLBW and pulmonary morbidity. The higher prevalence of respiratory composite morbidity in VLBW infants persists over the years until adolescence. The respiratory morbidity is most evident in the first year of life and declines afterward.

Addressing Preterm Birth History With Clinical Practice Recommendations Across the Life Course

Preterm birthrates, coupled with excellent preterm birth survival rates, guarantee that every health care provider, regardless of specialty, is caring for patients who were born preterm. Patients and families may not share a preterm birth history however, eliciting this information is important for mitigating potential risk. Long-term health outcomes research supports health implications associated with preterm birth throughout the life course. Through an in-depth review of literature and validation from health care experts in pediatric and adult care, recommendations for primary care providers were developed. The aim was to enhance the identification of those born prematurely, empower health care providers to employ familiar screening strategies, and advocate for mitigations strategies with anticipatory guidance and health promotion. These recommendations advocate a paradigm shift toward proactive intervention, rather than the reactive practice of waiting for children to fail to meet specific milestones or begin to show comorbid tendencies.

Hydrogen sulfide, oxygen, and calcium regulation in developing human airway smooth muscle

Preterm infants can develop airway hyperreactivity and impaired bronchodilation following supplemental O2 (hyperoxia) in early life, making it important to understand mechanisms of hyperoxia effects. Endogenous hydrogen sulfide (H2 S) has anti-inflammatory and vasodilatory effects with oxidative stress. There is little understanding of H2 S signaling in developing airways. We hypothesized that the endogenous H2 S system is detrimentally influenced by O2 and conversely H2 S signaling pathways can be leveraged to attenuate deleterious effects of O2 . Using human fetal airway smooth muscle (fASM) cells, we investigated baseline expression of endogenous H2 S machinery, and effects of exogenous H2 S donors NaHS and GYY4137 in the context of moderate hyperoxia, with intracellular calcium regulation as a readout of contractility. Biochemical pathways for endogenous H2 S generation and catabolism are present in fASM, and are differentially sensitive to O2 toward overall reduction in H2 S levels. H2 S donors have downstream effects of reducing [Ca2+ ]i responses to bronchoconstrictor agonist via blunted plasma membrane Ca2+ influx: effects blocked by O2 . However, such detrimental O2 effects are targetable by exogenous H2 S donors such as NaHS and GYY4137. These data provide novel information regarding the potential for H2 S to act as a bronchodilator in developing airways in the context of oxygen exposure.

Umbrella Review of School Age Health Outcomes of Preterm Birth Survivors

Preterm birth affects approximately 10% of U.S. births, with survival rates close to 95%. All health care providers, regardless of population or setting, are treating preterm birth survivors. The purpose of this manuscript is to present an umbrella review of the health outcomes of 2- to 12-year-old children who were born preterm. The current umbrella review consisted of 29 reviews, 14 meta-analyses, eight systematic reviews, and seven described as both meta-analysis and systematic review. Studies were grouped into six health outcome categories: neurodevelopmental, motor and/or cerebral palsy, pulmonary, mental and/or behavioral health, quality of life and/or leisure, and eczema. The analysis supports a resounding recommendation to recognize preterm birth, at all gestations, as a risk factor to health and educational outcomes. Increased attention to developmental screenings is critical, specifically recognition that children who are on the lower ranges of normal may benefit from therapies or interventions that support the attainment of future skills.

Voice and Exercise Related Respiratory Symptoms in Extremely Preterm Born Children After Neonatal Patent Ductus Arteriosus

Objective: To investigate voice characteristics and exercise related respiratory symptoms in extremely preterm born 11-year-old children, focusing particularly on associations with management of a patent ductus arteriosus (PDA). Study design: Prospective follow-up of all children born in Norway during 1999-2000 at gestational age <28 weeks or with birthweight <1,000 g. Neonatal data were obtained prospectively on custom-made registration forms completed by neonatologists. Voice characteristics and exercise related respiratory symptoms were obtained at 11 years by parental questionnaires. Result: Questionnaires were returned for 228/372 (61%) eligible children, of whom 137 had no history of PDA. PDA had been noted in 91 participants, of whom 36 had been treated conservatively, 21 with indomethacin, and 34 with surgery. Compared to the children treated with indomethacin or conservatively, the odds ratio (95% confidence interval) for the surgically treated children were 3.4 (1.3; 9.2) for having breathing problems during exercise, 16.9 (2.0; 143.0) for having a hoarse voice, 4.7 (1.3; 16.7) for a voice that breaks when shouting, 4.6 (1.1; 19.1) for a voice that disturbs singing, and 3.7 (1.1; 12.3) for problems shouting or speaking loudly. The significance of surgery per se was uncertain since the duration of mechanical ventilation was associated with the same outcomes. Conclusion: Extremely preterm born children with a neonatal history of PDA surgery had more problems with voice and breathing during exercise in mid-childhood than those whose PDA had been handled otherwise. The study underlines the causal heterogeneity of exercise related respiratory symptoms in preterm born children.

Highlights and recent developments in airway diseases in EAACI journals (2018)

The European Academy of Allergy and Clinical Immunology (EAACI) supports three journals: Allergy, Pediatric Allergy and Immunology, and Clinical and Translational Allergy. EAACI's major goals include supporting the promotion of health, in which the prevention of allergy and asthma plays a critical role, and disseminating the knowledge of allergic disease to all stakeholders. In 2018, the remarkable progress in the identification of basic mechanisms of allergic and respiratory diseases as well as the translation of these findings into clinical practice were observed. Last year's highlights include publication of EAACI guidelines for allergen immunotherapy, many EAACI Position Papers covering important aspects for the specialty, better understanding of molecular and cellular mechanisms, identification of biomarkers for disease prediction and progress monitoring, novel prevention and intervention studies, elucidation of mechanisms of multimorbidities, introduction of new drugs to the clinics, recently completed phase three clinical studies, and publication of a large number of allergen immunotherapy studies and meta-analyses.

Fractional exhaled nitric oxide in preterm-born subjects: A systematic review and meta-analysis

BACKGROUND

Decreased lung function is common in preterm-born survivors. Increased fractional exhaled nitric oxide (FeNO) appears to be a reliable test for eosinophillic airway inflammation especially in asthma. We, systematically, reviewed the literature to compare FeNO levels in preterm-born children and adults who did or did not have chronic lung disease of prematurity (CLD) in infancy with term-born controls.

METHODS

We searched eight databases up to February 2018. Studies comparing FeNO levels in preterm-born subjects (<37 weeks' gestation) in childhood and adulthood with and without (CLD) with term-born subjects were identified and extracted by two reviewers. Data were analysed using Review Manager v5.3.

RESULTS

From 6042 article titles, 183 full articles were screened for inclusion. Nineteen studies met the inclusion criteria. Seventeen studies compared FeNO levels in preterm- and term-born children and adults; 11 studies (preterm n = 640 and term n = 4005) were included in a meta-analysis. The mean FeNO concentration difference between the preterm-born and term-born group was -0.74 (95% CI -1.88 to 0.41) ppb. For the six studies reporting data on CLD (preterm n = 204 and term n = 211) the mean difference for FeNO levels was -2.82 (95% CI -5.87 to 0.22) ppb between the preterm-born CLD and term-born groups.

CONCLUSIONS

Our data suggest that preterm born children with and without CLD have similar FeNO levels to term-born children suggesting an alternative mechanism to eosinophilic inflammation for symptoms of wheezing and airway obstruction observed in preterm-born subjects.