Does nasal CPAP reduce bronchopulmonary dysplasia (BPD)?

Prophylactic or very early initiation of continuous positive airway pressure (CPAP) for preterm infants

BACKGROUND

Cohort studies have suggested that nasal continuous positive airway pressure (CPAP) starting in the immediate postnatal period before the onset of respiratory disease (prophylactic CPAP) may be beneficial in reducing the need for intubation and intermittent positive pressure ventilation (IPPV), and in preventing bronchopulmonary dysplasia (BPD), in preterm or low birth weight infants.

OBJECTIVES

To determine if prophylactic nasal CPAP (started within the first 15 minutes) or very early nasal CPAP regardless of respiratory status (started within the first hour of life), reduces the use of mechanical ventilation and the incidence of bronchopulmonary dysplasia without any adverse effects in preterm infants.

SEARCH METHODS

A comprehensive search was run on 6 November 2020 in the Cochrane Central Register of Controlled Trials (CENTRAL via CRS Web) and MEDLINE via Ovid. We also searched the reference lists of retrieved studies.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs) and quasi-RCTs in preterm infants (under 37 weeks of gestation). We included trials if they compared prophylactic nasal CPAP (started within the first 15 minutes) or very early nasal CPAP (started within the first hour of life) in infants with minimal signs of respiratory distress with 'supportive care', such as supplemental oxygen therapy, standard nasal cannula, or mechanical ventilation. We excluded studies where prophylactic CPAP was compared with CPAP along with co-interventions.

DATA COLLECTION AND ANALYSIS

We used the standard methods of Cochrane Neonatal, including independent study selection, assessment of trial quality, and extraction of data by two review authors.

MAIN RESULTS

We included eight trials (seven from the previous version of the review and one new study), recruiting 3201 babies, in the meta-analysis. Four trials, involving 765 babies, compared CPAP with supportive care, and three trials (2364 babies) compared CPAP with mechanical ventilation. One trial (72 babies) compared prophylactic CPAP with very early CPAP. Apart from a lack of blinding of the intervention, we judged seven studies to have a low risk of bias. However, one study had a high risk of selection bias. Prophylactic or very early CPAP compared to supportive care There may be a reduction in failed treatment (risk ratio (RR) 0.6, 95% confidence interval (CI) 0.49 to 0.74; risk difference (RD) -0.16, 95% CI -0.34 to 0.02; 4 studies, 765 infants; very low certainty evidence). CPAP possibly reduces BPD at 36 weeks (RR 0.76, 95% CI 0.51 to 1.14; 3 studies, 683 infants, moderate certainty evidence); there may be little or no difference in death (RR 1.04, 95% CI 0.56 to 1.93; 4 studies, 765 infants; moderate certainty evidence). Prophylactic CPAP may reduce the composite outcome of death or BPD (RR 0.69, 95% CI 0.40 to 1.19; 1 study, 256 infants; low certainty evidence). There may be no difference in pulmonary air leak (pneumothorax) (RR 0.75, 95% CI 0.35 to 1.16; 3 studies, 568 infants; low certainty evidence), or intraventricular haemorrhage (IVH) Grade 3 or 4 (RR 0.96, 95% CI 0.39 to 2.37; 2 studies, 486 infants; moderate certainty evidence). Neurodevelopmental impairment was not reported in any of the studies. Prophylactic or very early CPAP compared to mechanical ventilation There was probably a reduction in the incidence of BPD at 36 weeks (RR 0.89, 95% CI 0.8 to 0.99; RD -0.04, 95% CI -0.08 to 0.00; 3 studies, 2150 infants; moderate certainty evidence); and death or BPD (RR 0.89, 95% CI 0.81 to 0.97; RD -0.05, 95% CI -0.09 to 0.01; 3 studies, 2358 infants; moderate certainty evidence). There was also probably a reduction in the need for mechanical ventilation (failed treatment) (RR 0.49, 95% CI 0.45 to 0.54; RD -0.50, 95% CI -0.54 to -0.45; 2 studies, 1042 infants; moderate certainty evidence). There was probably a reduction in the incidence of death (RR 0.82, 95% CI 0.66 to 1.03; 3 studies, 2358 infants; moderate certainty evidence); pulmonary air leak (pneumothorax) (RR 1.24, 95% CI 0.91 to 1.69; 3 studies, 2357 infants; low certainty evidence); and IVH Grade 3 or 4 (RR 1.09, 95% CI 0.86 to 1.39; 3 studies, 2301 infants; moderate certainty evidence). One study in this comparison reported that there was probably little or no difference between the groups in the incidence of neurodevelopmental impairment at 18 to 22 months (RR 0.91, 95% CI 0.62 to 1.32; 976 infants; moderate certainty evidence). Prophylactic CPAP compared with very early CPAP There was one study in this comparison. We are very uncertain whether there is any difference in the incidence of BPD (RR 0.5, 95% CI 0.05 to 5.27; very low certainty evidence). The combined outcome of death and BPD was not reported, and failed treatment was reported but without data. There may have been little to no effect on death (RR 0.75, 95% CI 0.29 to1.94; 1 study, 72 infants; very low certainty evidence). Intraventricular haemorrhage Grade 3 or 4 and neurodevelopmental outcomes were not reported in this study. Pulmonary air leak (pneumothorax) was reported in this study, but there were no events in either group.

AUTHORS' CONCLUSIONS

For preterm and very preterm infants, there is insufficient evidence to evaluate prophylactic CPAP compared to oxygen therapy and other supportive care. When compared to mechanical ventilation, prophylactic nasal CPAP in very preterm infants reduces the incidence of BPD, the combined outcome of death and BPD, and mechanical ventilation. There is probably no difference in neurodevelopmental impairment at 18 to 22 months of age. When prophylactic CPAP is compared to early CPAP, we are very uncertain about whether there is any difference between prophylactic and very early CPAP. There is no information about the effect of prophylactic or very early CPAP in late preterm infants. There is one study awaiting classification.

Inhaled corticosteroids in ventilated preterm neonates: a non-randomized dose-ranging study

Background

Inhaled corticosteroids (ICS) offer targeted treatment for bronchopulmonary dysplasia (BPD) with minimal systemic effects compared to systemic steroids. However, dosing of ICS in the management of infants at high-risk of developing BPD is not well established. The objective of this study was to determine an effective dose of ICS for the treatment of ventilator-dependent infants to facilitate extubation or reduce fractional inspired oxygen concentration.

Methods

Forty-one infants born at < 32 weeks gestational age (GA) or < 1250 g who were ventilator-dependent at 10–28 days postnatal age were included. A non-randomized dose-ranging trial was performed using aerosolized inhaled beclomethasone with hydrofluoralkane propellant (HFA-BDP). Four dosing groups (200, 400, 600 and 800 μg twice daily for 1 week) with 11, 11, 10 and 9 infants in each group, respectively, were studied. The primary outcome was therapeutic efficacy (successful extubation or reduction in FiO₂ of > 75% from baseline) in ≥60% of infants in the group. Oxygen requirements, complications and long-term neurodevelopmental outcomes were also assessed.

Results

The median age at enrollment was 22 (10–28) postnatal days. The primary outcome, therapeutic efficacy as defined above, was not achieved in any group. However, there was a significant reduction in post-treatment FiO₂ at a dose of 800 μg bid. No obvious trends were seen in long-term neurodevelopmental outcomes.

Conclusions

Therapeutic efficacy was not achieved with all studied doses of ICS. A significant reduction in oxygen requirements was noted in ventilator-dependent preterm infants at 10–28 days of age when given 800 μg of HFA-BDP bid. Larger randomized trials of ICS are required to determine efficacy for the management of infants at high-risk for development of BPD.

Trial registration

This clinical trial was registered retrospectively on clinicaltrials.gov. The registration number is NCT03503994.

Surfactant utilization and short-term outcomes in an era of non-invasive respiratory support in Canadian neonatal intensive care units

OBJECTIVE

Increased use of non-invasive respiratory support (NRS) in the delivery room management of preterm neonates has resulted in delayed surfactant treatment, yet the short-term effects of this change are unknown. The aim of this study was to comparatively evaluate the use of surfactant and the short-term outcomes prior to and after the implementation of early routine use of NRS.

STUDY DESIGN

Eligible infants of <29 weeks gestational age (GA) admitted to a Canadian tertiary neonatal center during two time periods (2005 to 2008 and 2010 to 2013) were included in this retrospective cohort study. Timing of surfactant (prophylactic vs therapeutic) and short-term outcomes were compared between the two groups. Univariate and multivariate regression analysis was performed to determine the adjusted odds ratio (AOR) along with 95% confidence interval (CI) of receiving exogenous surfactant and developing bronchopulmonary dysplasia (BPD) using the later cohort as the reference group. Subgroup analyses were also performed for infants <26 and 26 to 28^6/7 weeks GA, respectively.

RESULTS

A total of 3980 and 5137 infants were included in the first and second time periods, respectively. There was no significant difference in overall surfactant utilization between the two time periods (AOR 1.00, 95% CI 0.89, 1.13). However, between 2005 and 2008, a lower proportion of neonates received therapeutic surfactant compared with the later cohort (47.1% vs 56.9%, P<0.01) but were more likely to receive prophylactic surfactant (52.9% vs 43.1%, P<0.01). BPD overall was significantly higher in the earlier cohort (AOR 1.19, 95% CI 1.07, 1.33), particularly among the <26 weeks gestation subgroup (AOR 1.34, 95% CI 1.08, 1.66).

CONCLUSION

Early routine use of NRS did not impact overall surfactant utilization rate, although therapeutic surfactant administration rates were higher with a concomitant decrease in BPD rates.

Prophylactic nasal continuous positive airway pressure for preventing morbidity and mortality in very preterm infants

BACKGROUND

Cohort studies have suggested that nasal continuous positive airways pressure (CPAP) starting in the immediate postnatal period before the onset of respiratory disease (prophylactic CPAP) may be beneficial in reducing the need for intubation and intermittent positive pressure ventilation (IPPV) and in preventing bronchopulmonary dysplasia (BPD) in preterm or low birth weight infants.

OBJECTIVES

To determine if prophylactic nasal CPAP started soon after birth regardless of respiratory status in the very preterm or very low birth weight infant reduces the use of IPPV and the incidence of bronchopulmonary dysplasia (BPD) without adverse effects.

SEARCH METHODS

We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL 2016, Issue 1), MEDLINE via PubMed (1966 to 31 January 2016), EMBASE (1980 to 31 January 2016), and CINAHL (1982 to 31 January 2016). 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

All trials using random or quasi-random patient allocation of very preterm infants (under 32 weeks' gestation) or less than 1500 grams at birth were eligible. We included trials if they compared prophylactic nasal CPAP started soon after birth regardless of the respiratory status of the infant with 'standard' methods of treatment such as IPPV, oxygen therapy or supportive treatment. We excluded studies where prophylactic CPAP was compared with CPAP along with other interventions.

DATA COLLECTION AND ANALYSIS

We used the standard methods of Cochrane and its Neonatal Review Group, including independent study selection, assessment of trial quality and extraction of data by two authors. Data were analysed using risk ratio (RR) and the meta-analysis was performed using a fixed-effect model.

MAIN RESULTS

Seven trials recruiting 3123 babies were included in the meta-analysis. Four trials recruiting 765 babies compared CPAP with supportive care and three trials (2364 infants) compared CPAP with mechanical ventilation. Apart from a lack of blinding of the intervention all studies were of low risk of bias.In the comparison of CPAP with supportive care there was a reduction in failed treatment (typical risk ratio (RR) 0.66, 95% confidence interval (CI) 0.45 to 0.98; typical risk difference (RD) -0.16, 95% CI -0.34 to 0.02; 4 studies, 765 infants, very low quality evidence). There was no reduction in bronchopulmonary dysplasia (BPD) or mortality.In trials comparing CPAP with assisted ventilation with or without surfactant, CPAP resulted in a small but clinically significant reduction in the incidence of BPD at 36 weeks, (typical RR 0.89, 95% CI 0.79 to 0.99; typical RD -0.04, 95% CI -0.08 to 0.00; 3 studies, 772 infants, moderate-quality evidence); and death or BPD (typical RR 0.89, 95% CI 0.81 to 0.97; typical RD -0.05, 95% CI -0.09 to 0.01; 3 studies, 1042 infants, moderate-quality evidence). There was also a clinically important reduction in the need for mechanical ventilation (typical RR 0.50, 95% CI 0.42 to 0.59; typical RD -0.49, 95% CI -0.59 to -0.39; 2 studies, 760 infants, moderate-quality evidence); and the use of surfactant in the CPAP group (typical RR 0.54, 95% CI 0.40 to 0.73; typical RD -0.41, 95% CI -0.54 to -0.28; 3 studies, 1744 infants, moderate-quality evidence).

AUTHORS' CONCLUSIONS

There is insufficient evidence to evaluate prophylactic CPAP compared to oxygen therapy and other supportive care. However when compared to mechanical ventilation prophylactic nasal CPAP in very preterm infants reduces the need for mechanical ventilation and surfactant and also reduces the incidence of BPD and death or BPD.

Acute Neonatal Respiratory Failure

Acute respiratory failure requiring assisted ventilation is one of the most common reasons for admission to the neonatal intensive care unit. Respiratory failure is the inability to maintain either normal delivery of oxygen to the tissues or normal removal of carbon dioxide from the tissues. It occurs when there is an imbalance between the respiratory workload and ventilatory strength and endurance. Definitions are somewhat arbitrary but suggested laboratory criteria for respiratory failure include two or more of the following: PaCO₂ > 60 mmHg, PaO₂ < 50 mmHg or O₂ saturation <80 % with an FiO₂ of 1.0 and pH < 7.25 (Wen et al. 2004).

The potential of non-invasive ventilation to decrease BPD

Bronchopulmonary dysplasia (BPD), the most common chronic lung disease in infancy, has serious long-term pulmonary and neurodevelopmental consequences right up to adulthood, and is associated with significant healthcare costs. BPD is a multifactorial disease, with genetic and environmental factors interacting to culminate in the characteristic clinical and pathological phenotype. Among the environmental factors, invasive endotracheal tube ventilation is considered a critical contributing factor to the pathogenesis of BPD. Since BPD currently has no specific preventive or effective therapy, considerable interest has focused on the use of non-invasive ventilation as a means to potentially decrease the incidence of BPD. This article reviews the progress made in the last 5 years in the use of nasal continuous positive airways pressure (NCPAP) and nasal intermittent positive pressure ventilation (NIPPV) as it pertains to impacting on BPD rates. Research efforts are summarized, and some guidelines are suggested for clinical use of these techniques in neonates.

Neurodevelopmental outcomes of extremely low birth weight infants ventilated with continuous positive airway pressure vs. mechanical ventilation

OBJECTIVE

To compare continuous positive airway pressure (CPAP) vs. traditional mechanical ventilation (MV) at 24 h of age as predictors of neurodevelopmental (ND) outcomes in extremely low birth weight (ELBW) infants at 18-22 months corrected gestational age (CGA).

METHODS

Infants ≤1000 g birth weight born from January 2000 through December 2006 at two hospitals at the Cincinnati site of the National Institute of Child Health and Human Development Neonatal Research Network were evaluated comparing CPAP (n = 198) vs. MV (n = 109). Primary outcomes included the Bayley Score of Infant Development Version II (BSID-II), presence of deafness, blindness, cerebral palsy, bronchopulmonary dysplasia and death.

RESULTS

Ventilatory groups were similar in gender, rates of preterm prolonged rupture of membranes, antepartum hemorrhage, use of antenatal antibiotics, steroids, and tocolytics. Infants receiving CPAP weighed more, were older, were more likely to be non-Caucasian and from a singleton pregnancy. Infants receiving CPAP had better BSID-II scores, and lower rates of BPD and death.

CONCLUSIONS

After adjusting for acuity differences, ventilatory strategy at 24 h of age independently predicts long-term neurodevelopmental outcome in ELBW infants.

Trends in use of neonatal CPAP: a population-based study

BACKGROUND

Continuous positive airway pressure (CPAP) is used widely to provide respiratory support for neonates, and is often the first treatment choice in tertiary centres. Recent trials have demonstrated that CPAP reduces need for intubation and ventilation for infants born at 25-28 weeks gestation, and at > 32 weeks, in non-tertiary hospitals, CPAP reduces need for transfer to NICU. The aim of this study was to examine recent population trends in the use of neonatal continuous positive airway pressure.

METHODS

We undertook a population-based cohort study of all 696,816 liveborn neonates ≥24 weeks gestation in New South Wales (NSW) Australia, 2001-2008. Data were obtained from linked birth and hospitalizations records, including neonatal transfers. The primary outcome was CPAP without mechanical ventilation (via endotracheal intubation) between birth and discharge from the hospital system. Analyses were stratified by age ≤32 and > 32 weeks gestation.

RESULTS

Neonates receiving any ventilatory support increased from 1,480 (17.9/1000) in 2001 to 2,486 (26.9/1000) in 2008, including 461 (5.6/1000) to 1,465 (15.8/1000) neonates who received CPAP alone. There was a concurrent decrease in mechanical ventilation use from 12.3 to 11.0/1000. The increase in CPAP use was greater among neonates > 32 weeks (from 3.2 to 11.8/1000) compared with neonates ≤32 weeks (from 18.1 to 32.7/1000). The proportion of CPAP > 32 weeks initiated in non-tertiary hospitals increased from 6% to 30%.

CONCLUSIONS

The use of neonatal CPAP is increasing, especially > 32 weeks gestation and among non-tertiary hospitals. Recommendations are required regarding which infants should be considered for CPAP, resources necessary for a unit to offer CPAP and monitoring of longer term outcomes.

Current methods of non-invasive ventilatory support for neonates

Non-invasive ventilatory support can reduce the adverse effects associated with intubation and mechanical ventilation, such as bronchopulmonary dysplasia, sepsis, and trauma to the upper airways. In the last 4 decades, nasal continuous positive airway pressure (CPAP) has been used to wean preterm infants off mechanical ventilation and, more recently, as a primary mode of respiratory support for preterm infants with respiratory insufficiency. Moreover, new methods of respiratory support have been developed, and the devices used to provide non-invasive ventilation (NIV) have improved technically. Use of NIV is increasing, and a variety of equipment is available in different clinical settings. There is evidence that NIV improves gas exchange and reduces extubation failure after mechanical ventilation in infants. However, more research is needed to identify the most suitable devices for particular conditions; the NIV settings that should be used; and whether to employ synchronized or non-synchronized NIV. Furthermore, the optimal treatment strategy and the best time for initiation of NIV remain to be identified. This article provides an overview of the use of non-invasive ventilation (NIV) in newborn infants, and the clinical applications of NIV.

Risk factors for bronchopulmonary dysplasia in five Portuguese neonatal intensive care units

The pathogenesis of bronchopulmonary dysplasia (BPD) is clearly multifactorial. Specific pathogenic risk factors are prematurity, respiratory distress, oxygen supplementation, mechanical ventilation (MV), inflammation, patent ductus arteriosus (PDA), etc.

AIM

To evaluate BPD prevalence and to identify risk factors for BPD in five Portuguese Neonatal Intensive Care Units in order to develop better practices the management of these newborns.

MATERIAL AND METHODS

256 very low birth weight infants with gestational age (GA) <30 weeks and/or birthweight (BW) <1250 g admitted in five Portuguese NICUs, between 2004 and 2006 were studied. A protocol was filled in based on clinical information registered in the hospital charts. BPD was defined as oxygen dependency at 36 weeks of postconceptional age.

RESULTS

BPD prevalence was 12.9% (33/256). BPD risk decreased 46% per GA week and of 39% per 100g BW. BPD risk was significantly higher among newborns with low BW (adj OR= 0.73, 95% CI=0.57- 0.95), severe hyaline membrane disease (adj OR= 9.85, 95% CI=1.05-92.35), and those with sepsis (adj OR=6.22, 95% CI=1.68-23.02), those with longer duration on ventilatory support (42 vs 3 days, respectively in BPD and no BPD patients, p <0.001) and longer duration of FiO2>0.30 (85 vs 5 days, respectively in BPD and no BPD patients, p <0.001).

COMMENTS

The most relevant risk factors were low birth weight, severe hyaline membrane disease, duration of respiratory support and oxygen therapy, and nosocomial sepsis. The implementation of potentially better practices to reduce lung injury in neonates must be addressed to improve practices to decrease these risk factors.

Chronic lung disease of prematurity: a short history

Chronic lung disease of prematurity (CLD) is commonly considered to be a consequence of assisted ventilation. However, prior to the description in 1967 of bronchopulmonary dysplasia (BPD), following ventilator therapy for respiratory distress syndrome, Wilson-Mikity syndrome (WMS) had been described in very preterm infants on minimal oxygen supplementation. In the 1970s and 1980s, many infants treated with assisted ventilation required prolonged mechanical ventilation after developing radiographic features of coarse infiltrates, severe hyperinflation, and microcystic changes, associated with hypercarbemia and the need for increased inspired oxygen concentrations. Some infants died and showed evidence of pulmonary fibrosis, obstructive bronchiolitis, and dysplastic change. The role of supplemental oxygen, positive pressure ventilation, and the immaturity of the lung have long been considered important in the etiology of CLD/BPD. More recently, the role of inflammation (particularly antenatal exposure to cytokines) and individual susceptibility (genetic predisposition) have assumed greater etiologic importance. The historical setting into which corticosteroid treatment for BPD was introduced is also discussed. After the licensing of exogenous surfactant to treat RDS in the early 1990s and more widespread use of prenatal corticosteroids in the mid-1990s, severe BPD became an unusual event. Gradually, the diagnosis of CLD, still often referred to as BPD, was based on an oxygen requirement at 36 weeks postmenstrual age. However, it is not clear that this 'new BPD' is substantially different from WMS. It is difficult to make prognostications about long-term lung function of these infants based on oxygen 'requirement' at 36 weeks, since supplemental oxygen is frequently used unnecessarily.