Trial of Selective Early Treatment of Patent Ductus Arteriosus with Ibuprofen.

BACKGROUND: The cyclooxygenase inhibitor ibuprofen may be used to treat patent ductus arteriosus (PDA) in preterm infants. Whether selective early treatment of large PDAs with ibuprofen would improve short-term outcomes is not known. METHODS: We conducted a multicenter, randomized, double-blind, placebo-controlled trial evaluating early treatment (≤72 hours after birth) with ibuprofen for a large PDA (diameter of ≥1.5 mm with pulsatile flow) in extremely preterm infants (born between 23 weeks 0 days' and 28 weeks 6 days' gestation). The primary outcome was a composite of death or moderate or severe bronchopulmonary dysplasia evaluated at 36 weeks of postmenstrual age. RESULTS: A total of 326 infants were assigned to receive ibuprofen and 327 to receive placebo; 324 and 322, respectively, had data available for outcome analyses. A primary-outcome event occurred in 220 of 318 infants (69.2%) in the ibuprofen group and 202 of 318 infants (63.5%) in the placebo group (adjusted risk ratio, 1.09; 95% confidence interval [CI], 0.98 to 1.20; P = 0.10). A total of 44 of 323 infants (13.6%) in the ibuprofen group and 33 of 321 infants (10.3%) in the placebo group died (adjusted risk ratio, 1.32; 95% CI, 0.92 to 1.90). Among the infants who survived to 36 weeks of postmenstrual age, moderate or severe bronchopulmonary dysplasia occurred in 176 of 274 (64.2%) in the ibuprofen group and 169 of 285 (59.3%) in the placebo group (adjusted risk ratio, 1.09; 95% CI, 0.96 to 1.23). Two unforeseeable serious adverse events occurred that were possibly related to ibuprofen. CONCLUSIONS: The risk of death or moderate or severe bronchopulmonary dysplasia at 36 weeks of postmenstrual age was not significantly lower among infants who received early treatment with ibuprofen than among those who received placebo. (Funded by the National Institute for Health Research Health Technology Assessment Programme; Baby-OSCAR ISRCTN Registry number, ISRCTN84264977.).

The Bronchopulmonary Dysplasia score: A predictive model for bronchopulmonary dysplasia or death in high-risk preterm infants.

AIM: Progressive respiratory deterioration in infants at high risk of bronchopulmonary dysplasia (BPD) is associated with patent ductus arteriosus (PDA) exposure. This study aimed to design an early predictive model for BPD or death in preterm infants using early echocardiographic markers and clinical data. METHODS: Infants born with gestational age (GA) ≤ 29 weeks and/or birth weight (BW) < 1500 g at Cork University Maternity Hospital, Ireland were retrospectively evaluated. Those with echocardiography performed between 36 h and 7 days of life were eligible for inclusion. Exclusion criteria were pulmonary hypertension and major congenital anomalies. The primary outcome was a composite of BPD and death before discharge. RESULTS: The study included 99 infants. A predictive model for the primary outcome was developed, which included three variables (BW, Respiratory Severity Score and flow pattern across the PDA), and yielding an area under the curve of 0.98 (95% CI 0.96-1.00, p < 0.001). Higher scores were predictive of the primary outcome. A cut-off of -1.0 had positive and negative predictive values of 89% and 98%, and sensitivity and specificity of 98% and 88%, respectively. CONCLUSION: Our prediction model is an accessible bedside tool that predicts BPD or death in premature infants.

Mortality in Outpatients with Bronchopulmonary Dysplasia.

OBJECTIVES: To study the demographic and clinical characteristics of preterm infants with bronchopulmonary dysplasia (BPD) to identify the factors most strongly predictive of outpatient mortality, with the goal of identifying those individuals at greatest risk. STUDY DESIGN: Demographic and clinical characteristics were retrospectively reviewed for 862 subjects recruited from an outpatient BPD clinic. Characteristics of the deceased and living participants were compared using nonparametric analysis. Regression analysis was performed to identify factors associated with mortality. RESULTS: Of the 862 subjects, 13 (1.5%) died during follow-up, for an overall mortality rate of approximately 15.1 deaths per 1000 subjects. Two patients died in the postneonatal period (annual mortality incidence, 369.9 per 100 000), 9 died between age 1 and 4 years (annual mortality incidence, 310.2 per 100 000), and 2 died between age of 5 and 14 years (annual mortality incidence, 71.4 per 100 000). After adjusting for gestational age and BPD severity, mortality was found to be associated with the amount of supplemental oxygen required at discharge from the neonatal intensive care unit (adjusted hazard ratio [aHR], 4.10; P = .001), presence of a gastrostomy tube (aHR, 8.13; P = .012), and presence of a cerebrospinal fluid (CSF) shunt (aHR, 4.31; P = .021). CONCLUSIONS: The incidence of mortality among preterm infants with BPD is substantially higher than that seen in the general population. The need for greater amounts of home supplemental oxygen and the presence of a gastrostomy tube or CSF shunt were associated with an increased risk of postdischarge mortality. Future studies should focus on clarifying risk factors for the development of severe disease to allow for early identification and treatment of those at highest risk.

Increased circulating cytokeratin 19 fragment levels in preterm neonates receiving mechanical ventilation are associated with poor outcome.

Invasive mechanical ventilation and oxygen toxicity are postnatal contributors to chronic lung disease of prematurity, also known as bronchopulmonary dysplasia (BPD). Cyfra 21-1 is a soluble fragment of cytokeratin 19, which belongs to the cytoskeleton stabilizing epithelial intermediate filaments. As a biomarker of structural integrity, Cyfra 21-1 might be associated with airway injury and lung hypoplasia in neonates. Serum Cyfra 21-1 concentrations for 80 preterm and 80 healthy term newborns were measured within 48 h after birth. Preterm infants with the combined endpoint BPD/mortality had significantly higher Cyfra 21-1 levels compared with those without fulfilling BPD/mortality criteria (P = 0.01). Also, severe RDS (>grade III) was associated with higher Cyfra levels (P = 0.01). Total duration of oxygen therapy was more than five times longer in neonates with high Cyfra 21-1 levels (P = 0.01). Infants with higher Cyfra 21-1 values were more likely to receive mechanical ventilation (50% vs. 17.5%). However, the duration of mechanical ventilation was similar between groups. The median Cyfra value was 1.93 ng/mL (IQR: 1.68-2.53 ng/mL) in healthy term neonates and 8.5 ng/mL (IQR: 3.6-16.0 ng/mL) in preterm infants. Using ROC analysis, we calculated a Cyfra cutoff > 8.5 ng/mL to predict BPD/death with an AUC of 0.795 (P = 0.004), a sensitivity of 88.9%, and a specificity of 55%. Mortality was predicted with a cutoff > 17.4 ng/mL (AUC: 0.94; P = 0.001), a sensitivity of 100%, and a specificity of 84%. These findings suggest that Cyfra 21-1 concentration might be useful to predict poor outcome in premature infants.

Loop Diuretics in Severe Bronchopulmonary Dysplasia: Cumulative Use and Associations with Mortality and Age at Discharge.

OBJECTIVES: To measure between-center variation in loop diuretic use in infants developing severe bronchopulmonary dysplasia (BPD) in US children's hospitals, and to compare mortality and age at discharge between infants from low-use centers and infants from high-use centers. STUDY DESIGN: We performed a retrospective cohort study of preterm infants at <32 weeks of gestational age with severe BPD. The primary outcome was cumulative loop diuretic use, defined as the proportion of days with exposure between admission and discharge. Infant characteristics associated with loop diuretic use at P < .10 were included in multivariable models to adjust for center differences in case mix. Hospitals were ranked from lowest to highest in adjusted use and dichotomized into low-use centers and high-use centers. We then compared mortality and postmenstrual age at discharge between the groups through multivariable analyses. RESULTS: We identified 3252 subjects from 43 centers. Significant variation between centers remained despite adjustment for infant characteristics, with use present in an adjusted mean range of 7.3% to 49.4% of days (P < .0001). Mortality did not differ significantly between the 2 groups (aOR, 0.98; 95% CI, 0.62-1.53; P = .92), nor did postmenstrual age at discharge (marginal mean, 47.3 weeks [95% CI, 46.8-47.9 weeks] in the low-use group vs 47.4 weeks [95% CI, 46.9-47.9 weeks] in the high-use group; P = .96). CONCLUSIONS: A marked variation in loop diuretic use for infants developing severe BPD exists among US children's hospitals, without an observed difference in mortality or age at discharge. More research is needed to provide evidence-based guidance for this common exposure.

Fluid status in the first 10 days of life and death/bronchopulmonary dysplasia among preterm infants.

OBJECTIVE: To investigate the association between fluid and sodium status in the first 10 postnatal days and death/bronchopulmonary dysplasia (BPD) among infants born <29 weeks' gestation. STUDY DESIGN: Single center retrospective cohort study (2015-2018) of infants born 23-28 weeks'. Three exposure variables were evaluated over the first 10 postnatal days: cumulative fluid balance (CFB), median serum sodium concentration, and maximum percentage weight loss. Primary outcome was death and/or BPD. Multivariable logistic regression adjusting for patient covariates was used to assess the association between exposure variables and outcomes. RESULTS: Of 191 infants included, 98 (51%) had death/BPD. Only CFB differed significantly between BPD-free survivors and infants with death/BPD: 4.71 dL/kg (IQR 4.10-5.12) vs 5.11 dL/kg (IQR 4.47-6.07; p < 0.001). In adjusted analyses, we found an association between higher CFB and higher odds of death/BPD (AOR 1.56, 95% CI 1.11-2.25). This was mainly due to the association of CFB with BPD (AOR 1.60, 95% CI 1.12-2.35), rather than with death (AOR 1.08, 95% CI 0.54-2.30). CONCLUSION: Among preterm infants, a higher CFB in the first 10 days after delivery is associated with higher odds of death/BPD. IMPACT: Previous studies suggest that postnatal fluid status influences survival and respiratory function in neonates. Fluid balance, serum sodium concentration, and daily weight changes are commonly used as fluid status indicators in neonates. We found that higher cumulative fluid balance in the first 10 days of life was associated with higher odds of death/bronchopulmonary dysplasia in neonates born <29 weeks. Monitoring of postnatal fluid balance may be an appropriate non-invasive strategy to favor survival without bronchopulmonary dysplasia. We developed a cumulative fluid balance chart with corresponding thresholds on each day to help design future trials and guide clinicians in fluid management.

Antenatal N-acetylcysteine to improve outcomes of premature infants with intra-amniotic infection and inflammation (Triple I): randomized clinical trial.

BACKGROUND: Intrauterine infection and/or inflammation (Triple I) is an important cause of preterm birth (PTB) and adverse newborn outcomes. N-acetylcysteine (NAC) is a Food and Drug Administration (FDA)-approved drug safely administered to pregnant women with acetaminophen toxicity. METHODS: We conducted a single-center, quadruple-blind, placebo-controlled trial of pregnant women with impending PTB due to confirmed Triple I. Participants (n = 67) were randomized to an intravenous infusion of NAC or placebo mimicking the FDA-approved regimen. Outcomes included clinical measures and mechanistic biomarkers. RESULTS: Newborns exposed to NAC (n = 33) had significantly improved status at birth and required less intensive resuscitation compared to placebo (n = 34). Fewer NAC-exposed newborns developed two or more prematurity-related severe morbidities [NAC: 21% vs. placebo: 47%, relative risk, 0.45; 95% confidence interval (CI) 0.21-0.95] with the strongest protection afforded against bronchopulmonary dysplasia (BPD, NAC: 3% vs. placebo: 32%, relative risk, 0.10; 95% CI: 0.01-0.73). These effects were independent of gestational age, birth weight, sex, or race. Umbilical cord plasma NAC concentration correlated directly with cysteine, but not with plasma or whole blood glutathione. NAC reduced the placental expression of histone deacetylase-2, suggesting that epigenetic mechanisms may be involved. CONCLUSIONS: These data provide support for larger studies of intrapartum NAC to reduce prematurity-related morbidity. IMPACT: In this randomized clinical trial of 65 women and their infants, maternal intravenous NAC employing the FDA-approved dosing protocol resulted in lower composite neonatal morbidity independent of gestational age, race, sex, and birthweight. Administration of NAC in amniocentesis-confirmed Triple I resulted in a remarkably lower incidence of BPD. As prior studies have not shown a benefit of postnatal NAC in ventilated infants, our trial highlights the critical antenatal timing of NAC administration. Repurposing of NAC for intrapartum administration should be explored in larger clinical trials as a strategy to improve prematurity-related outcomes and decrease the incidence of BPD.

Multicenter Experience with Neurally Adjusted Ventilatory Assist in Infants with Severe Bronchopulmonary Dysplasia.

OBJECTIVE: The aim of this study is to determine patterns of neurally adjusted ventilatory assist (NAVA) use in ventilator-dependent preterm infants with evolving or established severe bronchopulmonary dysplasia (sBPD) among centers of the BPD Collaborative, including indications for its initiation, discontinuation, and outcomes. STUDY DESIGN: Retrospective review of infants with developing or established sBPD who were placed on NAVA after ≥4 weeks of mechanical ventilation and were ≥ 30 weeks of postmenstrual age (PMA). RESULTS: Among the 13 sites of the BPD collaborative, only four centers (31%) used NAVA in the management of infants with evolving or established BPD. A total of 112 patients met inclusion criteria from these four centers. PMA, weight at the start of NAVA and median number of days on NAVA, were different among the four centers. The impact of NAVA therapy was assessed as being successful in 67% of infants, as defined by the ability to achieve respiratory stability at a lower level of ventilator support, including extubation to noninvasive positive pressure ventilation or support with a home ventilator. In total 87% (range: 78-100%) of patients survived until discharge. CONCLUSION: We conclude that NAVA can be used safely and effectively in selective infants with sBPD. Indications and current strategies for the application of NAVA in infants with evolving or established BPD, however, are highly variable between centers. Although this pilot study suggests that NAVA may be successfully used for the management of infants with BPD, sufficient experience and well-designed clinical studies are needed to establish standards of care for defining the role of NAVA in the care of infants with sBPD.

Hydrocortisone for Preventing Mortality and Bronchopulmonary Dysplasia in Preterm Infants with or without Chorioamnionitis Exposure: A Meta-Analysis of Randomized Trials.

OBJECTIVE: This study sought to assess whether infants exposed to chorioamnionitis are the optimal population to benefit the most from early postnatal hydrocortisone delivery in preventing bronchopulmonary dysplasia (BPD). This meta-analysis was conducted to discover the efficacy of hydrocortisone in preterm infants with and without chorioamnionitis. STUDY DESIGN: From the earliest available date until March 2018, studies, review articles, and papers published in PubMed, Ovid, and Web of Science were reviewed. Randomized controlled trials comparing hydrocortisone with placebo/no intervention in preterm infants with a known status of chorioamnionitis exposure were included. RESULTS: Early postpartum low-dose hydrocortisone prevents the combined outcome of neonatal BPD or death in infants weighing less than 1,000 g with chorioamnionitis exposure (odds ratio [95% confidence interval]: 0.52 [0.32-0.79]; risk difference: -0.15 [-0.24 to -0.06]; number needed to treat: 6 [4-16]) but not in infants without chorioamnionitis exposure. Further secondary analysis showed no significant difference between the hydrocortisone group and the placebo group in individual outcomes of BPD or death, regardless of infant exposure to chorioamnionitis. CONCLUSION: Early application of low-dose hydrocortisone could potentially prevent BPD or death in infants weighing less than 1,000 g with exposure to chorioamnionitis. This finding provides the basis for further study in this target group.

Trends in Perinatal Practices and Neonatal Outcomes of Very Low Birth Weight Infants during a 16-year Period at NEOCOSUR Centers.

OBJECTIVE: To describe trends in mortality, major morbidity, and perinatal care practices of very low birth weight infants born at NEOCOSUR Neonatal Network centers from January 1, 2001, through December 31, 2016. STUDY DESIGN: A retrospective analysis of prospectively collected data from all inborn infants with a birthweight of 500-1500 g and 23-35 weeks of gestation. RESULTS: We examined data for 13 987 very low birth weight infants with a mean birth weight of 1081 ± 281 g and a gestational age of 28.8 ± 2.9 weeks. Overall mortality was 26.8% without significant changes throughout the study period. Decreases in early onset sepsis from 6.3% to 2.8% (P <.001), late onset sepsis from 21.1% to 19.5% (P = .002), retinopathy of prematurity from 21.3% to 13.8% (P <.001), and hydrocephalus from 3.8% to 2.4% (P <.001), were observed. The incidence for bronchopulmonary dysplasia decreased from 17.3% to 16% (P = .043), incidence of severe intraventricular hemorrhage was 10.4%, necrotizing enterocolitis 11.1%, and periventricular leukomalacia 3.8%, and did not change over the study period. Administration of antenatal corticosteroids increased from 70.2% to 82.3% and cesarean delivery from 65.9% to 75.4% (P <.001). The use of conventional mechanical ventilation decreased from 67.7% to 63.9% (P <.001) and continuous positive airway pressure use increased from 41.3% to 64.3% (P <.001). Survival without major morbidity increased from 37.4% to 44.5% over the study period (P <.001). CONCLUSIONS: Progress in perinatal and neonatal care at network centers was associated with an improvement in survival without major morbidity of very low birth weight infants during a 16-year period. However, overall mortality remained unchanged.

ELBW infants receive inadvertent sodium load above the recommended intake.

BACKGROUND: To determine total sodium load, including inadvertent load, during the first 2 postnatal weeks, and its influence on serum sodium, morbidity, and mortality in extremely low birth weight (ELBW, birth weight <1000 g) infants and to calculate sodium replacement models. METHODS: Retrospective data analysis on ELBW infants with a gestational age <28 + 0/7 weeks. RESULTS: Ninety patients with a median birth weight of 718 g and a median gestational age of 24 + 6/7 weeks were included. Median sodium intake during the first 2 postnatal weeks was 10.2 mmol/kg/day, which was significantly higher than recommended (2-5 mmol/kg/day). Sodium intake did not affect the risk for hypernatremia. Each mmol of sodium intake during the first postnatal week was associated with an increased risk of bronchopulmonary dysplasia (45%) and higher-grade intraventricular hemorrhage (31%), during the second postnatal week for necrotizing enterocolitis (19%), and during both postnatal weeks of mortality (13%). Calculations of two sodium replacement models resulted in a decrease in sodium intake during the first postnatal week of 3.2 and 4.0 mmol/kg/day, respectively. CONCLUSIONS: Sodium load during the first 2 postnatal weeks of ELBW infants was significantly higher than recommended owing to inadvertent sodium intake and was associated with a higher risk of subsequent morbidity and mortality, although the study design does not allow conclusions on causality. Replacement of 0.9% saline with alternative carrier solutions might reduce sodium intake. IMPACT: Sodium intake in ELBW infants during the first 2 postnatal weeks was twofold to threefold higher than recommended; this was mainly caused by inadvertent sodium components. High sodium intake is not related to severe hypernatremia but might be associated with a higher morbidity in terms of BPD, IVH, and NEC. Inadvertent sodium load can be reduced by replacing high sodium-containing carrier solutions with high levels of sodium with alternative hypotonic and/or balanced fluids, model based.

Inhaled nitric oxide (iNO) for preventing prematurity-related bronchopulmonary dysplasia (BPD): 7-year follow-up of the European Union Nitric Oxide (EUNO) trial.

OBJECTIVES: Most studies of inhaled nitric oxide (iNO) for prevention of bronchopulmonary dysplasia (BPD) in premature infants have focused on short-term mortality and morbidity. Our aim was to determine the long-term effects of iNO. METHODS: A 7-year follow-up was undertaken of infants entered into a multicenter, double-blind, randomized, placebo-controlled trial of iNO for prevention of BPD in premature infants born between 24 and 28 weeks plus six days of gestation. At 7 years, survival and hospital admissions since the 2-year follow-up, home oxygen therapy in the past year, therapies used in the previous month and growth assessments were determined. Questionnaires were used to compare general health, well-being, and quality of life. RESULTS: A total of 305 children were assessed. No deaths were reported. Rates of hospitalization for respiratory problems (6.6 vs. 10.5%, iNO and placebo group, respectively) and use of respiratory medications (6.6 vs. 9.2%) were similar. Two patients who received iNO and one who received placebo had received home oxygen therapy. There were no significant differences in any questionnaire-documented health outcomes. CONCLUSIONS: iNO for prevention of BPD in very premature infants with respiratory distress did not result in long-term benefits or adverse long-term sequelae. In the light of current evidence, routine use of iNO cannot be recommended for prevention of BPD in preterm infants.

Effect of Maternal Docosahexaenoic Acid Supplementation on Bronchopulmonary Dysplasia-Free Survival in Breastfed Preterm Infants: A Randomized Clinical Trial.

Importance: Maternal docosahexaenoic acid (DHA) supplementation may prevent bronchopulmonary dysplasia, but evidence remains inconclusive. Objective: To determine whether maternal DHA supplementation during the neonatal period improves bronchopulmonary dysplasia-free survival in breastfed infants born before 29 weeks of gestation. Design, Setting, and Participants: Superiority, placebo-controlled randomized clinical trial at 16 Canadian neonatal intensive care units (June 2015-April 2018 with last infant follow-up in July 2018). Lactating women who delivered before 29 weeks of gestation were enrolled within 72 hours of delivery. The trial intended to enroll 800 mothers, but was stopped earlier. Interventions: There were 232 mothers (273 infants) assigned to oral capsules providing 1.2 g/d of DHA from randomization to 36 weeks' postmenstrual age and 229 mothers (255 infants) assigned to placebo capsules. Main Outcomes and Measures: The primary outcome was bronchopulmonary dysplasia-free survival in infants at 36 weeks' postmenstrual age. There were 22 secondary outcomes, including mortality and bronchopulmonary dysplasia. Results: Enrollment was stopped early due to concern for harm based on interim data from this trial and from another trial that was published during the course of this study. Among 461 mothers and their 528 infants (mean gestational age, 26.6 weeks [SD, 1.6 weeks]; 253 [47.9%] females), 375 mothers (81.3%) and 523 infants (99.1%) completed the trial. Overall, 147 of 268 infants (54.9%) in the DHA group vs 157 of 255 infants (61.6%) in the placebo group survived without bronchopulmonary dysplasia (absolute difference, -5.0% [95% CI, -11.6% to 2.6%]; relative risk, 0.91 [95% CI, 0.80 to 1.04], P = .18). Mortality occurred in 6.0% of infants in the DHA group vs 10.2% of infants in the placebo group (absolute difference, -3.9% [95% CI, -6.8% to 1.4%]; relative risk, 0.61 [95% CI, 0.33 to 1.13], P = .12). Bronchopulmonary dysplasia occurred in 41.7% of surviving infants in the DHA group vs 31.4% in the placebo group (absolute difference, 11.5% [95% CI, 2.3% to 23.2%]; relative risk, 1.36 [95% CI, 1.07 to 1.73], P = .01). Of 22 prespecified secondary outcomes, 19 were not significantly different. Conclusions and Relevance: Among breastfed preterm infants born before 29 weeks of gestation, maternal docosahexaenoic acid supplementation during the neonatal period did not significantly improve bronchopulmonary dysplasia-free survival at 36 weeks' postmenstrual age compared with placebo. Study interpretation is limited by early trial termination. Trial Registration: ClinicalTrials.gov Identifier: NCT02371460.

Improved survival and survival without bronchopulmonary dysplasia in very low birth weight infants after active perinatal care.

BACKGROUND: Perinatal and neonatal care for very low birth weight (VLBW) infants have changed significantly during the past two decades. However, it is unclear how these changes have affected neonatal mortality and morbidity in developing countries. OBJECTIVES: The aim of this study was to investigate the impact of the advanced neonatal care on short-term outcomes of VLBW infants. METHODS: A retrospective study was performed to compare the mortality and morbidity of VLBW infants between period I (2007-2011) and period II (2012-2016) in our unit. RESULTS: A total of 188 infants in period I and 214 infants in period II were evaluated. The overall in-hospital mortality for VLBW infants dropped from 26.1% in period I to 13.1% in period II. The incidence of birth asphyxia decreased significantly during period II (10.1% [period I] vs 3.7% [period II]). The rate of nasal continuous positive airway pressure (NCPAP) use (69.8% vs 87.1%) and the duration of NCPAP therapy (median: 3 days [period I] vs 5 days [period II]) increased significantly, while the proportion of infants treated with mechanical ventilation and the duration of mechanical ventilation significantly decreased. There was a significant increase in the proportion of survivors without major neonatal morbidity, mainly due to a significant increase in the incidence of survival without bronchopulmonary dysplasia (BPD) (72.7% vs 82.8%). In contrast, the incidence of late-onset sepsis increased significantly during period II (7.9% vs 19.4%). CONCLUSIONS: Active perinatal care is associated with improvements in survival and survival free of BPD for VLBW infants. However, late-onset sepsis is still a major concern.

Association of Center-Specific Patient Volumes and Early Respiratory Management Practices with Death and Bronchopulmonary Dysplasia in Preterm Infants.

OBJECTIVES: To describe variability in admission volumes and approach to early respiratory support between neonatal intensive care units in the Australian and New Zealand Neonatal Network and to evaluate whether these center-specific factors are associated with death and bronchopulmonary dysplasia. STUDY DESIGN: This retrospective cohort study included 19 099 neonates born between 25 and 32 weeks' gestation and admitted to 1 of 25 NICUs from 2007 to 2013. Center-specific factors evaluated were annual admission volume and rate of using continuous positive airway pressure (CPAP) rather than intubation as the first mode of respiratory support. Logistic regression was used to examine any association of these center-specific factors with death, BPD, and death or survival with BPD (death/BPD). Analysis was performed separately for 2 gestation groups (25-28 weeks and 29-32 weeks inclusive). RESULTS: Admission volumes and rates of early CPAP use varied widely across centers. Higher admission volumes were associated with lower odds of death or survival with BPD in the 25-28 week group (aOR 0.93, 99% CI 0.88-0.99 per increase of 10 babies per center annually). Centers with higher early CPAP use did not have lower odds of death or BPD than centers that intubated more frequently. CONCLUSIONS: Higher admission volumes are associated with more favorable outcomes for the more preterm infants in the Australian and New Zealand Neonatal Network. Further investigation is required to explore why the individual benefits of early CPAP do not translate to better outcomes for centers that use this approach most frequently.

Bronchopulmonary Dysplasia in Very Preterm Infants with Symptomatic Congenital Cytomegalovirus Infection: A Propensity Score-Matched Analysis.

OBJECTIVE: To assess whether symptomatic congenital cytomegalovirus infection (cCMV) is associated with bronchopulmonary dysplasia (BPD) and mortality in very preterm infants (gestational age ≤32 weeks). STUDY DESIGN: We performed a retrospective study using the Kids' Inpatient Database for 2003, 2006, 2009, and 2012. Diagnoses of BPD and symptomatic cCMV were determined using the International Classification of Diseases, Ninth Revision, Clinical Modification codes. Among patients with in-hospital birth at ≤32 weeks of gestation, cases of symptomatic cCMV were matched with infants without cCMV using propensity score matching at 1:2 ratio. Outcomes of BPD and in-hospital mortality were assessed using conditional logistic regression. RESULTS: Of 204 818 in-hospital births with gestational age ≤32 weeks, we identified 208 cases of symptomatic cCMV, 177 of which underwent matching. Symptomatic cCMV was associated with higher odds of BPD (OR, 2.34; 95% CI, 1.41-3.87), but was not significantly associated with in-hospital all-cause mortality (OR, 1.18, 95% CI, 0.64-2.17). CONCLUSIONS: Symptomatic cCMV was associated with BPD but not with in-hospital mortality among very preterm infants. Further study is needed to determine the risk of BPD among infants with cCMV to allow for evaluation of possible preventive measures.

The Impact of Time Interval between Extubation and Reintubation on Death or Bronchopulmonary Dysplasia in Extremely Preterm Infants.

OBJECTIVE: To explore the relation between time to reintubation and death or bronchopulmonary dysplasia (BPD) in extremely preterm infants. STUDY DESIGN: This was a subanalysis from an ongoing multicenter observational study. Infants with birth weight ≤1250 g, requiring mechanical ventilation, and undergoing their first elective extubation were prospectively followed throughout hospitalization. Time to reintubation was defined as the time interval between first elective extubation and reintubation. Univariate and multivariate logistic regression analyses were performed to evaluate associations between time to reintubation, using different observation windows after extubation (24-hour intervals), and death/BPD (primary outcome) or BPD among survivors (secondary outcome). aORs were computed with and without the confounding effects of cumulative mechanical ventilation duration. RESULTS: Of 216 infants included for analysis, 103 (48%) were reintubated at least once after their first elective extubation. Reintubation was associated with lower gestational age/weight and greater morbidities compared with infants never reintubated. After adjusting for confounders, reintubation within observation windows ranging between 24 hours and 3 weeks postextubation was associated with increased odds of death/BPD (but not BPD among survivors), independent of the cumulative mechanical ventilation duration. Reintubation within 48 hours from extubation conferred higher risk-adjusted odds of death/BPD vs other observation windows. CONCLUSIONS: Although reintubation after elective extubation was independently associated with increased likelihood of death/BPD in extremely preterm infants, the greatest risk was attributable to reintubation within the first 48 hours postextubation. Prediction models capable of identifying the highest-risk infants may further improve outcomes.

Sensitivity analyses for average treatment effects when outcome is censored by death in instrumental variable models.

Two problems that arise in making causal inferences for nonmortality outcomes such as bronchopulmonary dysplasia (BPD) are unmeasured confounding and censoring by death, ie, the outcome is observed only when subjects survive. In randomized experiments with noncompliance and no censoring by death, instrumental variable (IV) methods can be used to control for the unmeasured confounding. But, when there is censoring by death, the average causal treatment effect cannot be identified under usual assumptions but can be studied for a specific subpopulation by using sensitivity analysis with additional assumptions. However, evaluating the local average treatment effect (LATE) in observational studies with censoring by death problems while controlling for unmeasured confounding is not well studied. We develop a novel sensitivity analysis method based on IV models for studying the LATE. Specifically, we present the identification results under an additional assumption and propose a three-step procedure for the LATE estimation. Also, we propose an improved two-step procedure by simultaneously estimating the instrument propensity score (ie, the probability of instrument given covariates) and the parameters induced by the assumption. We show with simulation studies that the two-step procedure can be more robust and efficient than the three-step procedure. Finally, we apply our sensitivity analysis methods to a study on the effect of delivery at high-level neonatal intensive care units on the risk of BPD.

Respiratory severity score as a predictive factor for severe bronchopulmonary dysplasia or death in extremely preterm infants.

BACKGROUND: Despite significant advances in neonatology, bronchopulmonary dysplasia (BPD) remains the most common cause of serious morbidity and mortality in premature infants. The aim of the present study was to determine associations between the respiratory severity score (RSS) with death or BPD in premature infants. METHODS: This was a retrospective study conducted between January 2010 and December 2014. We enrolled preterm infants with a gestational age of less than 28 weeks who were supported by mechanical ventilation for more than a week during the first 4 weeks of life. We collected the RSS scores on day of life 2, 7, 14, 21 and 28. The correlations between postnatal RSSs and death or severe BPD were analyzed using multivariate logistic regression. RESULTS: Of the 138 eligible infants, 66 infants (47.8%) either died or developed severe BPD. The RSS cut-off values for predicting severe BPD or death were 3.0 for postnatal day (PND) 14 with an odds ratio (OR) of 11.265 (p = 0.0006, 95% confidence interval (CI), 2.842 to 44.646), 3.6 for PND 21 with an OR of 15.162 (p = 0.0003, 95% CI, 3.467 to 66.316), and 3.24 for PND 28 with an OR of 10.713 (p = 0.0005, 95% CI, 2.825 to 40.630). CONCLUSION: Strong correlations were observed between the RSSs on PND 14, 21, and 28 and death or subsequent severe BPD. The RSS could provide a simple estimate of severe BPD or death., Further research with a larger study population is necessary to validate the usefulness of the RSS for predicting severe BPD or death.

Model that predicted death or disabilities in premature infants was valid at seven years of age.

AIM: Validated a model that used bronchopulmonary dysplasia (BPD), brain injuries measured using ultrasound and retinopathy of prematurity (ROP) to predict late death or disability in premature infants at seven years of age. METHODS: A retrospective study was performed at the 12 de Octubre Hospital neonatal unit in Madrid. A logistic model was applied to estimate the independent prognostic contribution of each morbidity, and the effect that the combination of morbidities had on the seven-year outcomes. The analysis was performed on the total cohort from 1991 to 2008 and on two subcohorts from 1991 to 1998 and 1999 to 2008. RESULTS: A total of 1001 children were included with a mean birth weight of 922 ± 208 g. Severe ROP was strongly associated with poor neurodevelopment, with an odds ratio (OR) 3.17 and 95% confidence interval (CI) of 1.56-6.50, and so was BPD (OR 1.52, 95% CI: 1.03-2.2). The combination of two neonatal morbidities increased the risk of a poor outcome (OR 4.44, 95% CI: 1.51-7.86). The model behaved differently in the two subcohorts. CONCLUSION: The prognostic model predicted a poor outcome at seven years of age when the subjects had at least two of the three morbidities.