Lung function and respiratory health at school age in ventilated very low birth weight infants

Respiratory management for extremely premature infants born at 22 to 23 weeks of gestation in proactive centers in Sweden, Japan, and USA

Survival of preterm newborn infants have increased steadily since the introduction of surfactant treatment and antenatal steroids. In the absence of randomized controlled trials on ventilatory strategies in extremely preterm infants, we present ventilatory strategies applied during the initial phase and the continued ventilatory care as applied in three centers with proactive prenatal and postnatal management and well documented good outcomes in terms of mortality and morbidity in this cohort of infants.

Effect of Invasive Mechanical Ventilation at Birth on Lung Function Later in Childhood

BACKGROUND

Despite recent neonatal care improvements, mechanical ventilation still remains a major cause of lung injury and inflammation. There is growing literature on short- and long-term respiratory outcomes in infants born prematurely in the post-surfactant era, but the exclusive role of mechanical ventilation at birth in lung function impairment is still unclear. The aim of this study was to assess the effect of neonatal mechanical ventilation on lung function parameters in children born ≤ 32 weeks of gestational age at 11 years of age.

MATERIALS AND METHODS

In total, 55 ex-preterm children born between January 1, 2006 and December 31, 2007 were enrolled at 11 years of age. Neonatal information was obtained from medical records. Information about family and personal clinical history was collected by questionnaires. At 11 years of age, we measured spirometry parameters, lung volumes, diffusing lung capacity, and fractional exhaled nitric oxide. In addition, an allergy evaluation by skin prick test and eosinophil blood count were performed. A multivariable linear or logistic regression analysis was performed to examine the associations of mechanical ventilation with respiratory outcomes, adjusting for confounders (maternal smoking during pregnancy, gestational age, surfactant replacement therapy, and BMI).

RESULTS

No difference in lung function evaluation between ventilated and unventilated children were found. No association was also found between mechanical ventilation with lung function parameters.

CONCLUSION

Mechanical ventilation for a short period at birth in preterm children was not associated with lung function impairment at 11 years of age in our study sample. It remains to define if ventilation may have a short-term effect on lung function, not evident at 11 years of age.

The Consensus Definition of Bronchopulmonary Dysplasia Is an Adequate Predictor of Lung Function at Preschool Age

BACKGROUND

Recent attempts to refine the definition bronchopulmonary dysplasia (BPD) have based its predictive capacity on respiratory outcome in the first 2 years of life, eliminating the pre-existing requirement of 28 days of oxygen therapy prior to 36 weeks postmenstrual age (PMA). The objective of this study was to assess the utility of the 2001 consensus definition in predicting impaired lung function at preschool age.

METHODS

This cohort study included children aged 4-6 years old who were born at gestational age (GA) <32 weeks or bodyweight <1500 g. Univariate and multivariate analyses were performed to assess differences in antenatal and neonatal variables between BPD and non-BPD children. All participants underwent incentive spirometry. Lung function parameters were contrasted with the Global Lung Function Initiative (GLI-2012) reference equations and, together with antenatal and neonatal variables, compared among the different subgroups (no BPD, mild BPD, and moderate-to-severe BPD). A multivariate model was generated to identify independent risk factors for impaired lung function.

RESULTS

GA, hemodynamically significant patent ductus arteriosus, and late sepsis were independent risk factors for the development of BPD. A total of 119 children underwent incentive spirometry. All lung function parameters were significantly altered relative to reference values. Greater impairment of lung function was observed in the mild BPD vs. the no BPD group (forced expiratory volume in the first 0.75 seconds [FEV_0.75]: -1.18 ± 0.80 vs. -0.55 ± 1.13; p = 0.010), but no difference in forced vital capacity (FVC) was observed (-0.32 ± 0.90 vs. -0.18 ± 1; p = 0.534). The moderate-to-severe BPD group exhibited the most severe FEV_0.75 reduction (FEV_0.75: -2.63 ± 1.18 vs. -0.72 ± 1.08; p = 0.000) and was the only condition with FVC impairment (FVC: -1.82 ± 1.12 vs. -0.22 ± 0.87; p = 0.000). The multivariate analysis identified a diagnosis of moderate-to-severe BPD as an independent risk factor for lung function impairment.

CONCLUSION

The 2001 consensus definition of BPD has adequate predictive capacity for lung function measured by spirometry at 4-6 years of age. Moderate-to-severe BPD was the best predictor of respiratory impairment. Children with mild BPD showed greater alteration of FEV_0.75 than those without BPD.

Description of a novel chest wall anomaly: The postprematurity thoracic dysplasia

BACKGROUND/PURPOSE

Many studies on ex-preterm babies were conducted to evaluate their respiratory sequelae, but, to our knowledge, the condition described in this paper was never reported before and is not included in the classifications of thoracic anomalies proposed so far.

METHODS

Clinical data and images of a novel thoracic deformity observed in the last 10 years are shown. This anomaly is characterized by an indentation of the ribs on both (less frequently one) anterolateral parts of the chest wall. All our patients with this condition were ex-preterm babies. We named this novel thoracic anomaly as "postprematurity thoracic dysplasia" (PPTD). Possible etiopathogenetic mechanisms and treatment options are discussed.

RESULTS

We observed 8 patients with variable range of respiratory symptoms. In 2 cases the malformation caused a severe functional restriction of lung volumes and surgery was performed to improve respiratory symptoms; in other cases the symptoms were mild or absent and the malformation was a matter of concern only for cosmesis.

CONCLUSIONS

PPTD is a novel thoracic anomaly typical of ex-preterms. Clinical relevance is variable. In severe cases surgery can be considered.

LEVEL OF EVIDENCE

IV.

Predictive effects of low birth weight and small for gestational age status on respiratory and nutritional outcomes in cystic fibrosis

INTRODUCTION

Prior literature shows that neonates with cystic fibrosis (CF) are more likely to be born low birth weight (LBW, <2500 grams) and/or small for gestational age (SGA, <10^th percentile for weight) than non-CF counterparts. There is limited literature exploring the predictive effects of birth parameters on long-term outcomes.

METHODS

The study population (CF Twin and Sibling Study) was recruited between 2000-2013 (n = 1677). Relationships between FEV₁ percent predicted at 6, 12, or 18 years or BMI z-score at 2, 6, 12, or 18 years, and predictor variables (LBW or SGA status) were assessed using adjusted linear regressions.

RESULTS

Mean birth weight was 3.3 ± 0.7 kg (Females: 3.2 ± 0.7kg; males: 3.4 ± 0.7kg) and mean gestational age was 38.4 ± 2.6 weeks, with 10.2% of participants classified as SGA. Predictors of LBW included female sex, pancreatic insufficiency, and prematurity. Predictors of SGA included female sex. After adjustment, LBW was associated with lower BMI at ages 2-12 years and SGA was associated with lower BMI at age 2 years. LBW was associated with lower FEV₁ percent predicted only at age 6 years. SGA was not associated with FEV₁.

CONCLUSIONS

We did not observe higher rates of LBW or SGA in full term infants compared to the general population. We observed associations particularly between LBW and BMI or FEV₁, but these associations decreased with age, suggesting that alternate factors contribute to outcomes over time. In lieu of the ability to target growth during gestation, efforts could be considered to optimize infant nutritional status, which may improve later life outcomes.

Role of oxidative stress in neonatal respiratory distress syndrome

Respiratory distress syndrome is the commonest respiratory disorder in preterm infants. Although it is well known that preterm birth has a key role, the mechanisms of lung injury have not been fully elucidated. The pathogenesis of this neonatal condition is based on the rapid formation of the oxygen reactive species, which surpasses the detoxification capacity of anti-oxidative defense system. The high reactivity of free radical leads to damage to a variety of molecules and may induce respiratory cell death. There is evidence that the oxidative stress involved in the physiopathology of this disease, is particularly related to oxygen supplementation, mechanical ventilation, inflammation/infection and diabetes. This narrative review summarizes what is known regarding the connection between oxidative stress and respiratory distress syndrome.

How best to capture the respiratory consequences of prematurity?

Chronic respiratory morbidity is a common complication of premature birth, generally defined by the presence of bronchopulmonary dysplasia, both clinically and in trials of respiratory therapies. However, recent data have highlighted that bronchopulmonary dysplasia does not correlate with chronic respiratory morbidity in older children born preterm. Longitudinally evaluating pulmonary morbidity from early life through to childhood provides a more rational method of defining the continuum of chronic respiratory morbidity of prematurity, and offers new insights into the efficacy of neonatal respiratory interventions. The changing nature of preterm lung disease suggests that a multimodal approach using dynamic lung function assessment will be needed to assess the efficacy of a neonatal respiratory therapy and predict the long-term respiratory consequences of premature birth. Our aim is to review the literature regarding the long-term respiratory outcomes of neonatal respiratory strategies, the difficulties of assessing dynamic lung function in infants, and potential new solutions.

Better measures are needed to predict chronic respiratory morbidity in survivors born prematurely http://ow.ly/1L3n30ihq9C

Lung-protective ventilatory strategies in intubated preterm neonates with RDS

This article provides a narrative review of lung-protective ventilatory strategies (LPVS) in intubated preterm infants with RDS. A description of strategies is followed by results on short-and long-term respiratory and neurodevelopmental outcomes. Strategies will include patient-triggered or synchronized ventilation, volume targeted ventilation, the technique of intubation, surfactant administration and rapid extubation to NCPAP (INSURE), the open lung concept, strategies of high-frequency ventilation, and permissive hypercapnia. Based on this review single recommendations on optimal LPVS cannot be made. Combinations of several strategies, individually applied, most probably minimize or avoid potential serious respiratory and cerebral complications like bronchopulmonary dysplasia and cerebral palsy.

Growth Deficiency in Cystic Fibrosis Is Observable at Birth and Predictive of Early Pulmonary Function

INTRODUCTION

Cystic fibrosis (CF) is a complex disease that includes both pulmonary and gastrointestinal challenges, resulting in decreased weight. Pulmonary symptoms of CF are extremely variable. Greater body mass at an early age is associated with improved pulmonary function, but it is unknown at what age weight becomes predictive of pulmonary disease severity. The purpose of this study was to investigate the relationship between birth weight and pulmonary function in CF.

METHODS

Birth weight and pulmonary data were obtained. Linear regressions were used to examine the relationship between these two variables. A one-tailed t-test was used to compare birth weights between CF patients and the national average.

RESULTS

Birth weight was significantly lower in babies with CF and correlated with pulmonary disease at ages 6 and 10 years but not with age at which Pseudomonas aeruginosa colonization was observed.

DISCUSSION

These data suggest that CF growth deficiency has prenatal origins. Early nutritional intervention for babies with CF and a low birth weight is warranted to maximize pulmonary potential.

Does chronic oxygen dependency in preterm infants with bronchopulmonary dysplasia at NICU discharge predict respiratory outcomes at 3 years of age?

OBJECTIVE

To determine whether chronic oxygen dependency at the time of discharge from the neonatal intensive care unit (NICU) in infants with bronchopulmonary dysplasia (BPD) predicts respiratory outcomes at 3 years.

STUDY DESIGN

Preterm infants ⩽1250 g without BPD, BPD and BPD with chronic oxygen dependency were identified from the Southern Alberta Perinatal Follow-up clinic database (1995-2007). Respiratory outcomes at 4, 8, 18 and 36 months corrected age following NICU discharge were examined. Univariate analyses were done.

RESULTS

Out of 1563 infants admitted to the NICU, 1212 survived. Complete follow-up data at 36 months were available for 1030 (85%) children. Children with BPD with or without chronic oxygen dependency had significantly (P<0.001) lower birth weights and gestational ages, and greater post-natal steroid use, compared with those with no BPD. At 4, 8 and 18 months follow-up, the use of respiratory medications and supplemental oxygen were both significantly higher in the BPD infants with chronic oxygen dependency group compared with the no-BPD group and BPD group. At 36 months, children in the BPD with chronic oxygen dependency group were more likely to use respiratory medications and supplemental oxygen vs the no-BPD or the BPD groups. At 4, 8 and 36 months of age, more children in the BPD with chronic oxygen dependency group had post-neonatal chronic lung disease (PNCLD) than children in the other groups, but at 36 months the difference was significant only for the BPD with chronic oxygen dependency vs no-BPD group (P<0.001).

CONCLUSIONS

At 36 months, children diagnosed with BPD with chronic oxygen dependency at NICU discharge were more likely to need respiratory medications and supplemental oxygen in the previous 12 months, as compared with no-BPD or BPD groups. They were also more likely to require frequent physician visits and have PNCLD at 3 years, as compared with the no-BPD group.