Duration of significant patent ductus arteriosus and bronchopulmonary dysplasia in extremely preterm infants

Early Echocardiographic Predictors of Eventual Need for Patent Ductus Arteriosus Treatment: A Retrospective Study

OBJECTIVE

Hemodynamically significant patent ductus arteriosus (hsPDA) in preterm neonates is associated with end-organ injury including intraventricular hemorrhage. Early treatment may reduce morbidities but may result in overtreatment. This study aimed to examine the association between commonly obtained echocardiographic markers within the first 12 hours of life and eventual treatment of an hsPDA.

STUDY DESIGN

Patients with <32 weeks' gestational age had blinded echocardiograms done within the first 12 hours of life as part of research protocols. Subsequent treatment of the patent ductus arteriosus (PDA) was determined by the clinical team independent of echocardiogram results. t-tests and chi-square tests were done for continuous data and categorical outcomes. A receiver operating curve was created to optimize cutoff values.

RESULTS

 Among 199 neonates studied (mean time of echocardiogram 6.7 h after birth), those needing PDA treatment had higher left ventricular output (LVO), right ventricular output (RVO), and superior vena cava (SVC) flow (p-values 0.007, 0.044, and 0.012, respectively). Cutoffs for predicting PDA treatment were LVO > 204 mL/kg/min (63% sensitivity, 66% specificity), RVO > 221 mL/kg/min or SVC flow > 99 mL/kg/min (sensitivities 70 and 43%, specificities 48 and 73%, respectively).

CONCLUSION

 Preterm neonates with higher markers of cardiac output in the first 12 hours of birth later required PDA treatment. These data are the first to use standard cardiac output measures in the first 12 hours of life to predict the need for future PDA treatment. Further prospective studies will need to be performed to corroborate these associations between echocardiographic markers and clinical outcomes/morbidities.

KEY POINTS

· Early diagnosis of hsPDA may prevent severe morbidity and death.. · There are echocardiographic markers beyond duct size and flow direction that may aid early diagnosis.. · Cardiac output markers within the first 12 hours of life may predict need for treatment of hsPDA..

Hemodynamically significant patent ductus arteriosus profile in preterm neonates (26-34 weeks' gestation) undergoing surfactant replacement therapy in India: a prospective observational study

Surfactant administration significantly improves respiratory outcomes in preterm infants with respiratory distress syndrome (RDS). However, surfactant administration may lead to hemodynamic alterations, particularly in the heart, affecting the patent ductus arteriosus (PDA), the consequences of which are not fully understood. This prospective observational study took place in an Indian neonatal care unit from July 2019 to November 2020, enrolling preterm neonates (26-34 weeks' gestation) with RDS needing non-invasive positive pressure ventilation. They were divided into two groups: those who received surfactant while on respiratory support and those who did not. All newborns in the study had an initial echocardiogram within 24 h to detect PDA flow. Subsequent echocardiograms were conducted between 48 and 72 h or earlier based on symptoms. Of 220 infants requiring respiratory support, 84 were enrolled, with 42 in each group. While demographic variables were similar, the surfactant group had a lower median gestational age (29.0 vs. 31.0 weeks). In the surfactant group, a significantly higher percentage of neonates had hemodynamically significant PDA (hsPDA) compared to the non-surfactant group (54.76% vs. 26.19%, P-value = .008). Multiple logistic regression found no significant association between gestation, birth weight, or shock and hsPDA occurrence. Pulmonary hemorrhage occurred more often in the surfactant group. Bronchopulmonary dysplasia (BPD), intraventricular hemorrhage (IVH) > grade 2, and necrotizing enterocolitis (NEC) ≥ grade 2 did not differ significantly between the groups. Surfactant therapy via the less invasive surfactant administration technique was associated with a higher incidence of hsPDA. While surfactant is crucial for neonatal respiratory care, its potential hemodynamic effects, including hsPDA, should be considered.

Genetic Foundation of Prostaglandin Metabolism Influences Patent Ductus Arteriosus Closure in Extremely Low Birth Weight Infants

OBJECTIVE

 Prostaglandins (PGs) play a major role in maintaining patency of the ductal arteriosus (DA). Pulmonary 15-hydroxyprostaglandin dehydrogenase (PGDH), which is ecoded by the hydroxyprostaglandin dehydrogenase (HPGD) gene, is the primary enzyme responsible for PG breakdown. Animal studies have shown HPGD-knockout mice have significantly higher prostaglandin E2 levels and no ductal remodeling. Functional variants of the HPGD gene that alter PG breakdown have not been studied in preterm infants with patent ductus arteriosus (PDA).

STUDY DESIGN

 This was an observational cohort study including extreme low birth weight (ELBW) infants classified as having spontaneous, medical, or procedural (transcatheter or surgical ligation) closure of their DA. Urine prostaglandin E metabolite (PGEM) levels were measured in ELBW infants following ibuprofen treatment using competitive ELISA. HPGD genetic variants rs8752, rs2612656, and rs9312555 were analyzed. Kruskal-Wallis, Fisher's exact, chi square, logistic regression, and Wilcoxon signed-rank tests were used; p < 0.05 was considered significant.

RESULTS

 Infants in the procedural closure group had a younger gestational age (GA). The incidence of spontaneous closure or medical closure was higher compared to procedural closure in the presence of any minor allele of rs8752 (67 and 27%, respectively; p = 0.01), when adjusted for GA and gender. Haplotype analysis of three variants of HPGD revealed differences when comparing the spontaneous and medical closure group to the procedural group (p < 0.05). Urinary PGEM levels dropped significantly in those ELBW infants who responded to ibuprofen (p = 0.003) in contrast to those who did not respond (p = 0.5).

CONCLUSION

 There was a different genotype distribution for the rs8752 genetic variant of the HPGD gene-as it relates to the mode of treatment for ELBW infants with PDA. We speculate that medical management in the presence of this variant facilitated additional PG breakdown, significantly abrogating the need for procedural closure. Additionally, differences in genotype and haplotype distributions implicate a specific HPGD genetic foundation for DA closure in ELBW infants.

KEY POINTS

· PGs and their metabolism play a major role in PDA patency or closure.. · Genetic variants of the HPGD gene influence mode of treatment of PDA in ELBW infants.. · ELBW infants with PDA that responded to medical closure had significantly decreased urine PGEM levels..

Patent ductus arteriosus management in very-low-birth-weight prematurity: a place for an early operation?

OBJECTIVES

The goal was to evaluate neonatal outcomes based on treatment strategies and time points for haemodynamically significant patent ductus arteriosus (hsPDA) in very-low-birth-weight preterm infants, with a particular focus on surgical closure.

METHODS

This retrospective study included very-low-birth-weight infants born between 2014 and 2021 who received active treatment for hsPDA. Neonatal outcomes were compared between (i) primary surgical closure versus primary ibuprofen; (ii) early (<14th post-natal day) versus late primary surgical closure (≥14th post-natal day); and (iii) primary versus secondary surgical closure after ibuprofen failure. Further analysis using 1:1 propensity score matching was performed. Logistic regression was conducted to analyse the risk factors for post-ligation cardiac syndrome (PLCS) and/or acute kidney injury (AKI).

RESULTS

A total of 145 infants with hsPDA underwent active treatment for closure. The in-hospital death rate and the incidence of severe bronchopulmonary dysplasia (BPD) were similar between the primary surgical closure group and the primary ibuprofen group in a 1:1 matched analysis. Severe BPD was significantly higher in the late surgical closure group than in the early primary surgical closure group with 1:1 propensity score matching (72.7% vs 40.9%, P=0.033). The secondary surgical closure group showed the mildest clinical condition; however, the probability of PLCS/AKI was highest (38.6%) compared to the early (15.2%) or the late primary surgical group (28.1%, P<0.001), especially in extremely premature infants (gestational age < 28 weeks).

CONCLUSIONS

Surgical patent ductus arteriosus closure is not inferior to pharmacologic treatment. Considering the harmful effect of a prolonged patent ductus arteriosus shunt exposure, a timely decision and timely efforts should be made to minimize the risk of severe BPD and PLCS/AKI after surgical closure.

Randomized Noninferiority Trial of Expectant Management versus Early Treatment of Patent Ductus Arteriosus in Preterm Infants

OBJECTIVE

The study aimed to investigate, whether expectant management is noninferior to early patent ductus arteriosus (PDA) treatment with regard to the composite of mortality and/or incidence of bronchopulmonary dysplasia (BPD) in very preterm infants.

STUDY DESIGN

A total of 208 very preterm infants of the gestational age <32 weeks, birth weight <1,500 g, chronological age <72 hours, and PDA >1.5 mm were randomized between the treatment or expectant management groups. Both, the intention-to-treat and per-protocol analyses were performed.

RESULTS

A total of 104 (50%) patients received rectal ibuprofen (n = 52) or intravenous acetaminophen (n = 52) within first 72 hours of life. In 104 (50%) infants, expectant management was used. Eight of them (8%) received rescue treatment at the median age of 7 (range: 6-13) days. PDA closure rates by the 10th day of life were 81% (n = 84) in the treatment arm, and 58% (n = 60) in the expectant management arm (p < 0.01). The median age at the time of ductus closure was 5 (range: 5-6) days in the treatment arm and 8 (range: 6-11) days in the expectant management arm (p < 0.01). At the time of discharge, ductus was closed in 83% of treated infants and in 78% of patients who were managed expectantly (p > 0.05). No significant difference between the groups was found for the primary clinical outcomes, BPD/death, or the secondary outcomes at a postmenstrual age of 36 weeks or discharge.

CONCLUSION

Expectant management is noninferior to early PDA treatment for reducing the incidence of death/BPD. Compared with the expectant management, early pharmacological treatment provides more frequent and faster PDA closure in preterm infants with gestational age <32 weeks, but it neither reduces morbidity nor improves survival rates.

KEY POINTS

· PDA persistence in very preterm infants is associated with an increased risk of BPD/death.. · PDA treatment accelerates ductus closure, but does not improve survival or reduce severe neonatal morbidity.. · Expectant management is not associated with a higher risk of BPD/death..

Active versus restrictive ligation strategy for patent ductus arteriosus - A retrospective two-center study of extremely preterm infants born between 22 + 0 and 25 + 6 weeks of gestational age

BACKGROUND

Patent ductus arteriosus (PDA) in premature infants is associated with adverse clinical outcomes. Mode and timing of treatment are still controversial. Data are limited in the most extremely premature infants <26 weeks of gestational age (GA), where clinical problems are most significant and patients are most vulnerable.

AIMS

To investigate whether different approaches to surgical closure of PDA in two large Swedish centers has an impact on clinical outcomes including mortality in extremely preterm infants born <26 weeks GA.

STUDY DESIGN

Retrospective, two-center, cohort study.

SUBJECTS

Infants born at 22+0-25+6 weeks GA between 2010 and 2016 at Uppsala University Children's Hospital (UUCH; n = 228) and Queen Silvia Children's Hospital Gothenburg (QSCHG; n = 220).

MAIN OUTCOME MEASURES

Survival, bronchopulmonary dysplasia (BPD), and retinopathy of prematurity (ROP).

RESULTS

Surgical closure of PDA was more common and performed earlier at QSCHG (50 % vs 16 %; median age 11 vs 44 days; p < 0.01). Survival was similar in both centres. There was a higher incidence of severe BPD and longer duration of mechanical ventilation at UUCH (p < 0.01). There was a higher incidence of ROP, IVH and sepsis at QSCH (p < 0.05, p < 0.01 and p < 0.01). A sub-group analysis matching all surgically treated infants at QSCHG with infants at UUCH with the same GA showed similar results as the total cohort.

CONCLUSION

Earlier and higher rate of surgical PDA closure in this cohort of extremely preterms born <26 weeks GA did not impact mortality but was associated with lower rates of severe BPD and higher rates of severe ROP.

Should we "eliminate" PDA shunt in preterm infants? A narrative review

The patent ductus arteriosus frequently poses a significant morbidity in preterm infants, subjecting their immature pulmonary vascular bed to substantial volume overload. This, in turn, results in concurrent hypoperfusion to post-ductal organs, and subsequently alters cerebral blood flow. In addition, treatment has not demonstrated definitive improvements in patient outcomes. Currently, the optimal approach remains a subject of considerable debate with ongoing research controversy regarding the best approach. This article provides a comprehensive review of existing literature.

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.).

Patent Ductus Arteriosus and Bronchopulmonary Dysplasia-Associated Pulmonary Hypertension: A Bayesian Meta-Analysis

Importance

Bronchopulmonary dysplasia (BPD) is often associated with pulmonary vascular disease and secondary pulmonary hypertension (PH). The pathogenesis of BPD-associated PH (BPD-PH) is complex and involves prenatal and postnatal factors that disrupt pulmonary vascular development, and patent ductus arteriosus (PDA) is a factor potentially associated with risk of BPD-PH that has been identified in very recent studies.

Objective

To explore the association of PDA with BPD-PH using a bayesian model-averaged (BMA) meta-analysis of studies.

Data Sources

PubMed and Embase were searched up to April 2023. Key search terms included BPD and PH.

Study Selection

Studies examining infants with gestational age 32 weeks or less and reporting data on PDA and risk of BPD-PH.

Data Extraction and Synthesis

This study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and the Meta-Analysis of Observational Studies in Epidemiology reporting guidelines. Two independent reviewers extracted data, with a third reviewer checking for accuracy and completeness. Data pooling and effect size calculations were performed by BMA.

Main Outcomes and Measures

The primary outcome was BPD-PH. BMA was used to calculate Bayes factors (BFs). The BF10 is the ratio of the probability of the data under the alternative hypothesis (H1, association of PDA with BPD-HP) over the probability of the data under the null hypothesis (H0).

Results

A total of 32 studies (8513 infants) were included. BMA showed that the evidence in favor of H1 was weak for any PDA (BF10 = 2.90; 10 studies), moderate for hemodynamically significant PDA (BF10 = 3.77; 3 studies), and extreme for surgically ligated or catheter-occluded PDA (BF10 = 294.9; 16 studies). In contrast, the evidence in favor of H0 was weak for medically treated PDA (BF10 = 0.55; 6 studies). In addition, BMA found strong evidence in favor of H1 when prolonged exposure to PDA was analyzed as a dichotomous variable (BF10 = 11.80; 6 studies) and extreme evidence (BF10 = 113.60; 3 studies) when PDA exposure time was analyzed as a continuous variable.

Conclusions and Relevance

In this bayesian meta-analysis, the data suggest that prolonged exposure to PDA might be associated with increased risk of pulmonary vascular disease in extremely preterm infants. This highlights the need to monitor for PH in high-risk preterm infants with prolonged exposure to PDA and to incorporate PH risk into clinical decisions regarding PDA management.

Fluid Intake in the First Week of Life and the Duration of Hemodynamically Significant Patent Ductus Arteriosus in Extremely Preterm Infants

OBJECTIVE

This study aimed to determine the association between daily fluid intake and the duration of hemodynamically significant patent ductus arteriosus (hsPDA).

STUDY DESIGN

This is a retrospective cohort study of extremely preterm infants (<29 weeks) admitted in the Neonatal Intensive Care Unit of the Advent Health for Children from January 2013 to March 2016, if hsPDA was diagnosed in first week of life and serial echocardiograms were available. Diagnosis of hsPDA was based on a scoring system and its duration was estimated from serial echocardiograms. Cohort was divided into two groups based on duration of hsPDA (<1week, group A and ≥1 week, group B). Daily fluid intake was categorized as prescribed and actual. Prescribed volume was ordered by clinicians based on birth weight, not including trophic feeds, intravenous (IV) boluses or transfusions, etc. Actual intake was calculated by the electronic medical records based on daily weights and included all enteral or parenteral fluids. Multivariate analysis was performed to determine an association between total daily fluid intake over the first week of life and the duration of hsPDA. Two groups were compared to observe the difference between prescribed and actual daily fluid intakes.

RESULTS

We enrolled 50 infants in group A and 76 in group B. Infants in group B were of significantly lower gestation and required prolonged ventilation and hospitalization. An association between higher fluid intake in the first 2 days of life and prolonged duration of hsPDA was confirmed by multivariate analysis. Actual fluid intake was significantly higher than prescribed total fluid intake in first 4 days of life for infants in both groups.

CONCLUSION

In extremely preterm infants, higher fluid intake in first 2 days of life is associated with prolonged duration of hsPDA. Actual daily fluid intake can be significantly higher than prescribed daily fluids due to daily weight changes and additional fluid administration.

KEY POINTS

· In preterm infants, actual daily fluid intake may be higher than prescribed volume.. · Higher daily fluid intake in first week of life is associated with prolonged duration of PDA.. · PDA scoring system can be helpful for objective assessment of PDA in preterm infants..

Impact of patent ductus arteriosus on non-invasive assessments of lung fluids in very preterm infants during the transitional period

This prospective observational study aimed to evaluate whether lung fluids, assessed by lung ultrasonography and transthoracic electrical bioimpedance (TEB), may be influenced by the presence of a haemodynamically significant patent ductus arteriosus (hsPDA) in very preterm infants during the transitional period. Infants < 32 weeks of gestational age (GA) admitted to the neonatal intensive care units of IRCCS AOU Bologna and Niguarda Metropolitan Hospital of Milan (Italy) underwent a daily assessment of a lung ultrasound score (LUS) and of a TEB-derived index of thoracic fluid contents (TFC) during the first 72 h after birth. Echocardiographic scans were simultaneously performed to evaluate the concomitant ductal status (hsPDA vs. restrictive or closed duct). The correlation between LUS, TFC, and the ductal status was tested using generalized estimating equations. Forty-six infants (median GA: 29 [interquartile range, IQR: 27-31] weeks; median birth weight: 1099 [IQR: 880-1406] g) were included. At each daily evaluation, the presence of a hsPDA was associated with significantly higher LUS and TFC compared with a restrictive or closed ductus (p < 0.01 for all comparisons). These results were confirmed significant even after adjustment for GA and for the ongoing modality of respiratory support. Conclusion: Even during the first 72 h of life, the presence of a hsPDA determines a significant increase in pulmonary fluids which can be non-invasively detected and monitored over time using lung ultrasonography and TEB. What is Known: • Lung ultrasonography provides a non-invasive assessment of lung fluids and is widely used in neonatal settings. • In preterm infants, the persistence of a haemodynamically significant patent ductus arteriosus (hsPDA) over the first weeks can negatively affect pulmonary outcomes. What is New: • The presence of aan hsPDA is associated with increased lung fluids since early postnatal phases. • Lung ultrasonography and transthoracic electrical bioimpedance can effectively monitor lung fluid clearance in preterm infants with a hsPDA during the transitional period, with potential clinical implications.

A nomogram for predicting the risk of Bronchopulmonary dysplasia in premature infants

Background

Bronchopulmonary dysplasia (BPD) is a prevalent and critical complication among premature infants, with potentially long-lasting adverse effetcs. The present study aimed to establish a nomogram model to predict the risk of BPD in premature infants born at <32 weeks gestational age.

Methods

A retrospective single-center study was conducted on premature infants admitted to the neonatal intensive care unit (NICU) of the Children's Hospital of Nanjing Medical University from January 2018 to December 2020. Data were collected from clinical medical records, including the perinatal data and the critical information after birth. Clinical parameters and features were analyzed using univariate and multivariate logistic regression. A nomogram based on clinical data was established and validated using bootstrapping samples. The specificity and sensitivity of the nomogram were estimated using the receiver operating characteristic (ROC) based area under the curve (AUC).

Results

A total of 542 premature babies were included, and 152 infants (28.04%) were diagnosed with BPD. Birth weight, cesarean delivery, invasive/non-invasive ventilation at day 7 and 14 were identified as significant factors (p < 0.05) using univariate and the multivariate logistic regression analysis, and were entered into a nomogram. The calibration curve for BPD probability demonstrated a favorable concurrence between actual probability and predicted ability of the BPD nomogram. The nomogram showed potential differentiation, with an AUC of 0.925, 89.90% sensitivity, 76.71% specificity, and 86.35% accuracy.

Conclusion

The nomogram developed in this study provides a straightforward tool to predict the probability of BPD and assist clinicians in optimizing treatment regimens for premature infants born at <32 weeks gestational age. This study highlights the importance of identifying and monitoring significant clinical factors associated with BPD in premature infants to improve clinical outcomes.

Bronchopulmonary Dysplasia: Pathogenesis and Pathophysiology

Bronchopulmonary dysplasia (BPD), also known as chronic lung disease, is the most common respiratory morbidity in preterm infants. "Old" or "classic" BPD, as per the original description, is less common now. "New BPD", which presents with distinct clinical and pathological features, is more frequently observed in the current era of advanced neonatal care, where extremely premature infants are surviving because of medical advancements. The pathogenesis of BPD is complex and multifactorial and involves both genetic and environmental factors. This review provides an overview of the pathology of BPD and discusses the influence of several prenatal and postnatal factors on its pathogenesis, such as maternal factors, genetic susceptibility, ventilator-associated lung injury, oxygen toxicity, sepsis, patent ductus arteriosus (PDA), and nutritional deficiencies. This in-depth review draws on existing literature to explore these factors and their potential contribution to the development of BPD.

Expectant Management or Early Ibuprofen for Patent Ductus Arteriosus

BACKGROUND

Cyclooxygenase inhibitors are commonly used in infants with patent ductus arteriosus (PDA), but the benefit of these drugs is uncertain.

METHODS

In this multicenter, noninferiority trial, we randomly assigned infants with echocardiographically confirmed PDA (diameter, >1.5 mm, with left-to-right shunting) who were extremely preterm (<28 weeks' gestational age) to receive either expectant management or early ibuprofen treatment. The composite primary outcome included necrotizing enterocolitis (Bell's stage IIa or higher), moderate to severe bronchopulmonary dysplasia, or death at 36 weeks' postmenstrual age. The noninferiority of expectant management as compared with early ibuprofen treatment was defined as an absolute risk difference with an upper boundary of the one-sided 95% confidence interval of less than 10 percentage points.

RESULTS

A total of 273 infants underwent randomization. The median gestational age was 26 weeks, and the median birth weight was 845 g. A primary-outcome event occurred in 63 of 136 infants (46.3%) in the expectant-management group and in 87 of 137 (63.5%) in the early-ibuprofen group (absolute risk difference, -17.2 percentage points; upper boundary of the one-sided 95% confidence interval [CI], -7.4; P<0.001 for noninferiority). Necrotizing enterocolitis occurred in 24 of 136 infants (17.6%) in the expectant-management group and in 21 of 137 (15.3%) in the early-ibuprofen group (absolute risk difference, 2.3 percentage points; two-sided 95% CI, -6.5 to 11.1); bronchopulmonary dysplasia occurred in 39 of 117 infants (33.3%) and in 57 of 112 (50.9%), respectively (absolute risk difference, -17.6 percentage points; two-sided 95% CI, -30.2 to -5.0). Death occurred in 19 of 136 infants (14.0%) and in 25 of 137 (18.2%), respectively (absolute risk difference, -4.3 percentage points; two-sided 95% CI, -13.0 to 4.4). Rates of other adverse outcomes were similar in the two groups.

CONCLUSIONS

Expectant management for PDA in extremely premature infants was noninferior to early ibuprofen treatment with respect to necrotizing enterocolitis, bronchopulmonary dysplasia, or death at 36 weeks' postmenstrual age. (Funded by the Netherlands Organization for Health Research and Development and the Belgian Health Care Knowledge Center; BeNeDuctus ClinicalTrials.gov number, NCT02884219; EudraCT number, 2017-001376-28.).

Patent ductus arteriosus (PDA) and pulmonary morbidity: can early targeted pharmacologic PDA treatment decrease the risk of bronchopulmonary dysplasia?

A persistent left-to-right shunt through a patent ductus arteriosus (PDA) increases the rate of pulmonary hydrostatic fluid filtration, impairs pulmonary mechanics, and prolongs the need for respiratory support. Infants with a moderate/large PDA shunt that persists for more than 7-14 days are at increased risk for developing bronchopulmonary dysplasia (BPD) if they also require invasive ventilation for more than 10 days. In contrast, infants who require invasive ventilation for less than 10 days have similar rates of BPD no matter how long they are exposed to a moderate/large PDA shunt. Although pharmacologic PDA closure decreases the risk of abnormal early alveolar development in preterm baboons that are ventilated for 2 weeks, the findings from recent randomized controlled trials, as well as a quality improvement project, suggest that routine early targeted pharmacologic treatments, as currently employed, do not appear to alter the incidence of BPD in human infants.

Delayed Surgical Closure of the Patent Ductus Arteriosus: Does the Brain Pay the Price?

OBJECTIVE

To investigate the relation between duration of hemodynamically significant patent ductus arteriosus (PDA), cerebral oxygenation, magnetic resonance imaging-determined brain growth, and 2-year neurodevelopmental outcome in a cohort of infants born preterm whose duct was closed surgically.

STUDY DESIGN

Infants born preterm at <30 weeks of gestational age who underwent surgical ductal closure between 2008 and 2018 (n = 106) were included in this observational study. Near infrared spectroscopy-monitored cerebral oxygen saturation during and up to 24 hours after ductal closure and a Bayley III developmental test at the corrected age of 2 years is the institutional standard of care for this patient group. Infants also had magnetic resonance imaging at term-equivalent age.

RESULTS

In total, 90 infants fulfilled the inclusion criteria (median [range]: 25.9 weeks [24.0-28.9]; 856 g [540-1350]. Days of a PDA ranged from 1 to 41. Multivariable linear regression analysis showed that duration of a PDA negatively influenced cerebellar growth and motor and cognitive outcome at 2 years of corrected age.

CONCLUSIONS

Prolonged duration of a PDA in this surgical cohort is associated with reduced cerebellar growth and suboptimal neurodevelopmental outcome.

Comparison of lung ultrasound scores with clinical models for predicting bronchopulmonary dysplasia

Lung ultrasound scores (LUSs) have been demonstrated to accurately predict moderate-to-severe bronchopulmonary dysplasia (msBPD). This study attempted to explore the additional value of LUSs for predicting msBPD compared to clinical multivariate models in different gestational age (GA) groups. The study prospectively recruited preterm infants with GA < 32 weeks. Lung ultrasound was performed on days 3, 7, 14, and 21 after birth. A linear mixed-effects regression model was used to evaluate LUS evolution in infants born before and after 28 weeks. The receiver operating characteristic (ROC) procedure was used to analyze the reliability of LUS and clinical multivariable models for predicting msBPD. The optimal time to predict msBPD in all infants was 7 days with a cut-off point of 5 (area under the ROC (AUROC) curve: 0.78, 95% confidence interval (CI): 0.71-0.84). In infants with GA ≥ 28 weeks, LUSs provided a moderate diagnostic accuracy for all four time points (AUROC curve: 0.74-0.78), and the AUROC curve for the clinical multivariable model on day 14 was 0.91 (95% CI: 0.84-0.96), which was significantly higher than that of LUSs (AUROC curve: 0.77, 95% CI: 0.68-0.85, P < 0.05). In infants born at 23-27 weeks, LUSs showed a low diagnostic accuracy with higher cut-off points to predict msBPD, and the AUROC curve for GA to predict msBPD was 0.75 (95% CI: 0.59-0.85), providing diagnostic accuracy similar to that of LUSs.  Conclusion: The contribution of LUSs to predict msBPD in infants with different GAs remains controversial and requires further investigation. What is Known: • Lung ultrasound scores (LUSs) have been demonstrated to accurately predict moderate-to-severe bronchopulmonary dysplasia in infants with gestational age (GA)＜32 weeks. What is New: • The LUSs evolution differed between extremely preterm infants born before 28 weeks and preterm infants born at 28-32 weeks of gestation. • LUSs provided similar moderate predictive performance as GA-adjusted LUS and clinical multivariate models in infants born after 28 weeks, while LUSs seem to be less helpful in infants born before 28 weeks.

Clinical Significance of Early Pulmonary Hypertension in Preterm Infants

OBJECTIVE

To characterize different phenotypes of early pulmonary hypertension (PH) in preterm infants and their respective associations with bronchopulmonary dysplasia (BPD) and survival.

STUDY DESIGN

A prospective cohort study in a tertiary university medical center from June 2016 until March 2019. Infants with a gestational age <30 weeks and/or a birth weight <1000 g were included. Echocardiographic assessment for PH was performed at 3-10 days after birth. Subsequent development of BPD at 36 weeks postmenstrual age and mortality were assessed.

RESULTS

Early PH was identified in 55% of 104 included infants, including 21% with persistent PH of the newborn (PPHN), 61% with flow-associated PH, and 18% PH without shunt. Only PPHN was associated with placental fetal vascular malperfusion, lower gestational age, and low Apgar score. Both PPHN and flow PH were associated with the development of BPD. Early PH was associated with poorer survival, driven by PPHN.

CONCLUSIONS

Early PH is highly prevalent (55%) in preterm infants and associated with the development of BPD, independent of the phenotype of PH. Infants with PPHN had the poorest survival. Early PH presents in various phenotypes characterized by differences in etiology, pathophysiology, and associated long-term sequelae.

Racial disparities in the development of comorbid conditions after preterm birth: A narrative review

Despite recognition and attempts to reduce racial disparities in perinatal outcomes, Black infants are still disproportionately represented among those who are born preterm. Postnatal investigations of racial disparities in comorbidities and outcomes after preterm birth are increasing, although their results and interpretations are conflicting. In the present review, we 1.) identify important methodological limitations of that literature 2.) summarize the conflicting literature investigating racial disparities, specifically Black-white differences, in postnatal comorbidities and outcomes after preterm birth 3.) describe mechanisms by which racism operates to contextualize our understanding to inform future work to actively reduce disparities in preterm birth and subsequently, its complications.

Effects of prophylactic indomethacin on morbidity and mortality in infants <25 weeks' gestation: a protocol driven intention to treat analysis

OBJECTIVE

To determine if prophylactic indomethacin (PINDO) decreases death or bronchopulmonary dysplasia-grades 2 and 3 (death/BPD) in newborns <25 weeks.

STUDY DESIGN

Intention-to-treat, cohort-controlled study of 106 infants admitted during three alternating epochs of PINDO or Expectant patent ductus arteriosus (PDA) management.

RESULTS

At 7-8 days 85% of Expectant Management epoch infants had a moderate/large PDA (median exposure was 23 days). Among PINDO epoch infants only 24% still had a PDA at 7-8 days. There were no significant differences in the incidence of death/BPD or of secondary outcomes (BPD, death, necrotizing enterocolitis/spontaneous perforations, or intraventricular hemorrhage (grades 3 or 4)) in either unadjusted or adjusted comparisons between infants born in a PINDO epoch and those born in the Expectant Management epoch.

CONCLUSION

Despite being at high risk for PDA-related morbidities, PINDO did not appear to alter the rates of our primary and secondary outcomes in infants <25 weeks.

Patent Ductus Arteriosus: A Contemporary Perspective for the Pediatric and Adult Cardiac Care Provider

The burden of patent ductus arteriosus (PDA) continues to be significant. In view of marked differences in preterm infants versus more mature, term counterparts (viewed on a continuum with adolescent and adult patients), mechanisms regulating ductal patency, genetic contributions, clinical consequences, and diagnostic and treatment thresholds are discussed separately, when appropriate. Among both preterm infants and older children and adults, a range of hemodynamic profiles highlighting the markedly variable consequences of the PDA are provided. In most contemporary settings, transcatheter closure is preferable over surgical ligation, but data on longer-term outcomes, particularly among preterm infants, are lacking. The present review provides recommendations to identify gaps in PDA diagnosis, management, and treatment on which subsequent research can be developed. Ultimately, the combination of refined diagnostic thresholds and expanded treatment options provides the best opportunities to address the burden of PDA. Although fundamental gaps remain unanswered, the present review provides pediatric and adult cardiac care providers with a contemporary framework in PDA care to support the practice of evidence-based medicine.

Percutaneous Closure of Patent Ductus Arteriosus

Percutaneous-based patent ductus arteriosus closure is technically feasible among infants less than 1.5 kg. However, marked heterogeneity in the type and nature of adverse events obscures current safety profile assessments. Although data on the risks of postdevice closure syndrome remain promising, a lack of comparative trials of surgical ductal ligation and inconsistent surveillance across published studies obscure confidence in present estimates of safety and efficacy. To minimize risk and yield the greatest benefits, clinical studies of patent ductus arteriosus treatment should consider incorporating more robust assessments to ensure that infants at greatest risk for adverse ductal consequences are included.

Patent ductus arteriosus, tracheal ventilation, and the risk of bronchopulmonary dysplasia

BACKGROUND

An increased risk for bronchopulmonary dysplasia (BPD) exists when moderate-to-large patent ductus arteriosus shunts (hsPDA) persist beyond 14 days.

GOAL

To examine the interaction between prolonged exposures to tracheal ventilation (≥10 days) and hsPDA on the incidence of BPD in infants <28 weeks gestation.

STUDY DESIGN

Predefined definitions of prolonged ventilation (≥10 days), hsPDA (≥14 days), and BPD (room air challenge test at 36 weeks) were used to analyze deidentified data from the multicenter TRIOCAPI RCT in a secondary analysis of the trial.

RESULTS

Among 307 infants who survived >14 days, 41 died before 36 weeks. Among survivors, 93/266 had BPD. The association between BPD and hsPDA depended on the length of intubation. In multivariable analyses, prolonged hsPDA shunts were associated with increased BPD (odds ratio (OR) (95% confidence interval (CI)) = 3.00 (1.58-5.71)) when infants required intubation for ≥10 days. In contrast, there was no significant association between hsPDA exposure and BPD when infants were intubated <10 days (OR (95% CI) = 1.49 (0.98-2.26)). A similar relationship between prolonged hsPDA and length of intubation was found for BPD/death (n = 307): infants intubated ≥10 days: OR (95% CI) = 2.41 (1.47-3.95)); infants intubated <10 days: OR (95% CI) = 1.37 (0.86-2.19)).

CONCLUSIONS

Moderate-to-large PDAs were associated with increased risks of BPD and BPD/death-but only when infants required intubation ≥10 days.

IMPACT

Infants with a moderate-to-large hsPDA that persist beyond 14 days are only at risk for developing BPD if they also receive prolonged tracheal ventilation for ≥10 days. Infants who receive less ventilatory support (intubation for <10 days) have the same incidence of BPD whether the ductus closes shortly after birth or whether it persists as a moderate-to-large shunt for several weeks. Early PDA closure may be unnecessary in infants who require short durations of intubation since the PDA does not seem to alter the incidence of BPD in infants who require intubation for <10 days.

A prediction model of pulmonary hypertension in preterm infants with bronchopulmonary dysplasia

OBJECTIVE

Pulmonary hypertension (PH) is a severe cardiovascular complication of bronchopulmonary dysplasia (BPD) that contributes to the high mortality rates for preterm infants. The objective of this study is to establish a prediction model of BPD-associated PH (BPD-PH) by integrating multiple predictive factors for infants with BPD.

METHOD

A retrospective investigation of the perinatal clinical records and data of echocardiography in all the preterm infants with BPD was performed from January 2012 to December 2019. A prediction model of BPD-PH was established based on the univariate and multivariate logistic regression analysis of the clinical data and evaluated by using the area under the receiver operating characteristic (ROC) curve (AUC), combined with the Hosmer-Lemeshow (HL) test. Internal validation was performed with bootstrap resampling.

RESULT

A total of 268 infants with BPD were divided into the BPD-PH group and the no-PH group. Multivariate logistic regression analysis showed that the independent predictive factors of BPD-PH were moderate to severe BPD, small for gestational age, duration of hemodynamically significant patent ductus arteriosus ≥ 28 days, and early PH. A prediction model was established based on the β coefficients of the four predictors. The area under the ROC curve of the prediction model was 0.930. The Hosmer-Lemeshow test (p = 0.976) and the calibration curve showed good calibration.

CONCLUSION

The prediction model based on the four risk factors predicts the development of BPD-PH with high sensitivity and specificity and might help clinicians to make individualized interventions to minimize the disease risk.

Impact of patent ductus arteriosus shunt size and duration on risk of death or severe respiratory morbidity in preterm infants born in China

The purpose of this study is to assess whether duration and size of the arterial duct were associated with severe respiratory morbidity and mortality in preterm infants. All echocardiography evaluations for patent ductus arteriosus (PDA) in a cohort of preterm infants, born at a gestational age less than 28 weeks, from birth up to 36 weeks of postconceptional age or final ductal closure were reviewed. Ductal size was measured at the pulmonary end. PDA was classified as small (E1: ductal diameter (DD) ≤ 1.5 mm), moderate (E2: 1.5 mm < DD ≤ 2.5 mm), or large (E3) (DD > 2.5 mm). The primary outcome was adverse outcome defined by the composite outcome of bronchopulmonary dysplasia (BPD) or death. Infants in whom the primary outcome occurred were classified as "high-risk" whereas patients who did not satisfy this outcome were classified as "low-risk". Intergroup comparison (high vs. low risk) was performed using univariate and multivariate analyses. A total of 135 infants, born between 2010 and 2020, were evaluated. The primary outcome was satisfied in 46 (34.1%) patients. The high-risk group was characterized by increased duration of exposure to PDA of any (E1/E2/E3) grade (44 vs. 25.5 days, p = .0004), moderate or large (E2/E3) PDA (30.5 vs. 11.5 days, p < .0001), moderate (E2) PDA (10.8 vs.6 days, p = 0.05), and large (E3) PDA (11.5 vs.0 days, p < .0001) compared with low-risk group. Lower gestational age, prolonged duration of mechanical ventilation, higher rate of inotrope use, pharmacological therapy, and PDA ligation were also associated with development of BPD or death (high-risk group). After adjusting for confounders, the rate of inotrope use [OR 2.688, 95% CI (1.011-7.142), p = 0.047], duration of large (E3) PDA [OR 1.060, 95% CI (1.005-1.118), p = 0.03], and mechanical ventilation [OR 1.130, 95% CI (1.064-1.200), p = 0.0001] were independently associated with the composite of BPD or death. Among infants who developed BPD, 27 were classified as grade I and 18 as grade II BPD, respectively. Infants with grade II BPD had prolonged MV (20.0 vs. 9.0 days, p = 0.024), prolonged exposure to PDA of any grade (55.8 vs. 36.0 days, p = 0.03), and prolonged exposure to large (E3) PDA compared with infants with grade I BPD.   Conclusion: Prolonged exposure to a large PDA was associated with severe respiratory morbidity and mortality in preterm infants. The modulator role of early intervention, in the most pathologic shunts, on severe respiratory morbidity in preterm infants should be tested in well-designed clinical trials. What is Known: • Current guidelines recommended against accelerating PDA closure of preterm infants within 2 weeks of life, with low certainty evidence indicating improved long-term outcomes. • Recent studies suggest that conservative approach regarding PDA management has detrimental effects on the respiratory outcomes in a subgroup population. What is New: • Persistent patency of significant PDA is associated with increased risk of BPD/death in extremely preterm infants. • Targeted intervention of PDA is beneficial for the at-risk preterm infants with increased PDA hemodynamic significance.

Fluid Intake in the First Week of Life and the Duration of Hemodynamically Significant Patent Ductus Arteriosus in Extremely Preterm Infants

OBJECTIVE

 This study aimed to determine the association between daily fluid intake and the duration of hemodynamically significant patent ductus arteriosus (hsPDA).

METHODS

 This is a retrospective cohort study of extremely preterm infants (<29 weeks) admitted in the Neonatal Intensive Care Unit of the Advent Health for Children from January 2013 to March 2016, if hsPDA was diagnosed in first week of life and serial echocardiograms were available. Diagnosis of hsPDA was based on a scoring system and its duration was estimated from serial echocardiograms. Cohort was divided into two groups based on duration of hsPDA (<1week, group A and ≥1 week, group B). Daily fluid intake was categorized as prescribed and actual. Prescribed volume was ordered by clinicians based on birth weight, not including trophic feeds, intravenous (IV) boluses or transfusions, etc. Actual intake was calculated by the electronic medical records based on daily weights and included all enteral or parenteral fluids. Multivariate analysis was performed to determine an association between total daily fluid intake over the first week of life and the duration of hsPDA. Two groups were compared to observe the difference between prescribed and actual daily fluid intakes.

RESULTS

 We enrolled 50 infants in group A and 76 in group B. Infants in group B were of significantly lower gestation and required prolonged ventilation and hospitalization. An association between higher fluid intake in the first 2 days of life and prolonged duration of hsPDA was confirmed by multivariate analysis. Actual fluid intake was significantly higher than prescribed total fluid intake in first 4 days of life for infants in both groups.

CONCLUSION

 In extremely preterm infants, higher fluid intake in first 2 days of life is associated with prolonged duration of hsPDA. Actual daily fluid intake can be significantly higher than prescribed daily fluids due to daily weight changes and additional fluid administration.

KEY POINTS

· In preterm infants, actual daily fluid intake may be higher than prescribed volume.. · Higher daily fluid intake in first week of life is associated with prolonged duration of PDA.. · PDA scoring system can be helpful for objective assessment of PDA in preterm infants..

Percutaneous Closure of the Patent Ductus Arteriosus in Very-Low-Weight Infants

In view of the known complications of drug therapy and open surgical ligation, and the potential for prolonged patent ductus arteriosus (PDA) exposure to be harmful, health care practitioners have sought new approaches to achieve definitive ductal closure. Interest in percutaneous (catheter-based) PDA closure has emerged within the neonatal community as a viable treatment option, because it has been fueled by recent procedural and device modifications, as well as mounting feasibility and safety data. Herein, we provide a contemporary review of percutaneous PDA closure among infants at the crux of the medical debate-very-low-weight infants (≤1,500 g), including: 1) characterization of traditional PDA treatments (drug therapy, open surgical ligation) and conservative (nonintervention) management options; 2) a general overview of the major procedural steps of percutaneous ductal closure, including efforts to reduce thrombotic complications and the emergence of a novel US Food and Drug Administration-approved device; 3) a systematic review and meta-analysis to better understand risk profiles of percutaneous PDA closure in this population; and 4) discussion of current gaps in our understanding of optimal PDA care, including the critical need for well-designed, randomized, controlled clinical trials.

Patent ductus arteriosus, systemic NT-proBNP concentrations and development of bronchopulmonary dysplasia in very preterm infants: retrospective data analysis from a randomized controlled trial

BACKGROUND

Patent ductus arteriosus (PDA) is a common complication in very preterm infants. It is known that there is an association between PDA and development of bronchopulmonary dysplasia (BPD) or death before the postmenstrual age (PMA) of 36 weeks, but this association remains one of the most controversial aspects of the problem. The study aimed to evaluate the relationship between PDA, serum NT-proBNP levels at 2-3 and 8-9 days of life, and BPD/death in very preterm infants.

METHODS

Data of 52 preterm infants with a gestational age < 32 weeks, chronological age < 72 h, and PDA diameter > 1.5 mm, enrolled in a randomized controlled trial, were used for the retrospective analysis. All patients underwent daily echocardiographic and two serum NT-proBNP measurements within the first 10 days after birth. Two groups of infants were formed retrospectively at PMA of 36 weeks depending on the outcome, BPD (n = 18)/death (n = 7) or survival without BPD (n = 27). Receiver operator characteristic (ROC) curve was used to evaluate the predictive performance of serum NT-proBNP levels for BPD/death occurrence.

RESULTS

The percentage of infants who received pharmacological treatment for PDA did not differ between the groups. Based on the area under the ROC curve, serum NT-proBNP levels on the 2-3 day of life (AUC = 0.71; 95% confidence interval (CI): 0.56-0.9; p = 0.014)) and on the 8-9 day of life (AUC = 0.76; 95% CI: 0.6-0.9; p = 0.002) could reliably predict BPD/death in very preterm infants who had PDA diameter > 1.5 mm in the first 72 h of life. Hemodynamically significant PDA (hsPDA) was significantly more often detected in newborns with BPD/death, however, treatment of infants with hsPDA did not reduce the incidence of BPD/death.

CONCLUSIONS

In very preterm infants with PDA > 1.5 mm at the age of 24-48 h, serum NT-proBNP concentration could reliably predict the development of BPD or death, regardless of the persistence of PDA, with the highest diagnostic value at 8-9 days.

TRIAL REGISTRATION

This study is registered in ClinicalTrials.gov - NCT03860428 on March 4, 2019.

The feasibility of ultrasound Graf method in screening infants and young children with congenital hip dysplasia and follow-up of treatment effect

BACKGROUND

Congenital hip dysplasia is a common limb deformity in infants and young children. This study aimed to clarify the feasibility of ultrasound Graf method in screening congenital hip dysplasia of infants and young children, and its application value in follow-up treatment.

METHODS

A total of 1,313 infants and young children with clinically suspected congenital hip dysplasia in our hospital from December 2016 to January 2018 were selected as the participants and were examined by ultrasound Graf method. The acetabulum shape and the measured values of α and β angles of the participants were observed. The development of the hip joint and distribution of congenital hip dysplasia were analyzed, and the treatment effect was followed up.

RESULTS

Among 1,313 infants and young children with suspected congenital hip dysplasia, the positive rate of congenital hip dysplasia was 6.02% (79/1,313). The lesions were located on both sides in 14 cases, on the left side in 67 cases, and on the right side in 26 cases. The α angle of cases with congenital hip dysplasia was significantly lower than that of normal cases, and the β angle was significantly higher than that of normal cases (P<0.05). Ultrasound follow-up results showed that out of 24 cases who underwent hip abduction exercises, 22 (91.67%) returned to normal, and the remaining 2 returned to normal after Pavlik sling treatment. Among 46 cases treated with Pavlik sling, 42 (91.30%) returned to normal, and the remaining 4 cases returned to normal after closed reduction and plaster fixation. A total of 9 participants underwent plaster fixation after closed reduction, all of which returned to normal.

CONCLUSIONS

Ultrasound Graf method can be used as the first choice for screening infants and young children with congenital hip dysplasia. It can be followed up to observe the clinical treatment effect, and it has high clinical application value.

Management of Patent Ductus Arteriosus in Premature Infants in 2020

The patent ductus arteriosus (PDA) is the most commonly found cardiac condition in neonates. While there have been several studies and thousands of publications on the topic, the decision to treat the PDA is still strongly debated among cardiologists, surgeons, and neonatologists. This is in part due to the shortage of long-term benefits with the interventions studied. Practice variations still exist within sub-specialties and centers. This article briefly summarizes the history, embryology and histology of the PDA. It also succinctly discusses the hemodynamic significance of a PDA which builds the framework to review all the available literature on PDA closure in premature infants, though not a paradigm shift just yet; it introduces transcatheter PDA closure (TCPC) as a possible armament to the clinician for this age-old problem.

Prolonged Tracheal Intubation and the Association Between Patent Ductus Arteriosus and Bronchopulmonary Dysplasia: A Secondary Analysis of the PDA-TOLERATE trial

In the PDA-TOLERATE trial, persistent (even for several weeks) moderate to large patent ductus arteriosus (PDA) was not associated with an increased risk of BPD when the infant required <10 days of intubation. However, in infants requiring intubation for ≥10 days, prolonged PDA exposure (≥11 days) was associated with an increased risk of moderate/severe BPD.

Patent Ductus Arteriosus of the Preterm Infant

Postnatal ductal closure is stimulated by rising oxygen tension and withdrawal of vasodilatory mediators (prostaglandins, nitric oxide, adenosine) and by vasoconstrictors (endothelin-1, catecholamines, contractile prostanoids), ion channels, calcium flux, platelets, morphologic maturity, and a favorable genetic predisposition. A persistently patent ductus arteriosus (PDA) in preterm infants can have clinical consequences. Decreasing pulmonary vascular resistance, especially in extremely low gestational age newborns, increases left-to-right shunting through the ductus and increases pulmonary blood flow further, leading to interstitial pulmonary edema and volume load to the left heart. Potential consequences of left-to-right shunting via a hemodynamically significant patent ductus arteriosus (hsPDA) include increased risk for prolonged ventilation, bronchopulmonary dysplasia, necrotizing enterocolitis or focal intestinal perforation, intraventricular hemorrhage, and death. In the last decade, there has been a trend toward less aggressive treatment of PDA in preterm infants. However, there is a subgroup of infants who will likely benefit from intervention, be it pharmacologic, interventional, or surgical: (1) prophylactic intravenous indomethacin in highly selected extremely low gestational age newborns with PDA (<26 + 0/7 weeks' gestation, <750 g birth weight), (2) early targeted therapy of PDA in selected preterm infants at particular high risk for PDA-associated complications, and (3) PDA ligation, catheter intervention, or oral paracetamol may be considered as rescue options for hsPDA closure. The impact of catheter-based closure of hsPDA on clinical outcomes should be determined in future prospective studies. Finally, we provide a novel treatment algorithm for PDA in preterm infants that integrates the several treatment modalities in a staged approach.

Risk factors associated with prolonged mechanical ventilation after surgical patent ductus arteriosus ligation in preterm infants

BACKGROUND

One of the main pathophysiologies of a hemodynamically significant patent ductus arteriosus (hsPDA) involves pulmonary over-circulation. However, PDA treatment does not present with uniform effects on pulmonary outcomes. We aimed to evaluate the clinical characteristics - in particular, respiratory parameters - associated with prolonged mechanical ventilation after PDA ligation.

METHODS

Preterm infants ≤32 weeks gestation were included in the study. Infants who underwent PDA ligation were grouped depending on whether the infant successfully was extubated ≤14 d after ligation or required prolonged invasive mechanical ventilation >14 d after ligation. The clinical characteristics, including the parameters concerning the respiratory illness severity and hemodynamical significance of PDA shunt, were compared between the two groups.

RESULTS

Among 172 preterm infants, 36 (20.9%) infants underwent surgical PDA ligation. Fifteen (41.6%) infants were successfully extubated at ≤14 d after ligation, and 21 (58.3%) infants required prolonged invasive mechanical ventilation for >14 d after ligation. In the univariable analysis, the infants who required prolonged mechanical ventilation was significantly smaller in terms of gestational age (GA) and birth weight and tended to present a greater respiratory illness severity [represented by the use of high-frequency oscillatory ventilation (HFOV) and greater RSS (respiratory severity score)/kg] with a larger PDA size prior to PDA ligation. In the multivariable logistic regression analysis, peak preoperative RSS/kg (p = 0.012, OR = 0.207, 95% CI = 0.060-0.706) was the only significant factor associated with prolonged mechanical ventilation after PDA ligation.

CONCLUSION

Preterm infants with the compromised respiratory condition may be prone to prolonged mechanical ventilation after PDA ligation. The respiratory status during the early phase of life should be considered when evaluating the effect of PDA treatment. With an extended view, distinguishing infants with such risk factors may lead to more polished treatment strategies toward hsPDA.

The effect of prolonged tracheal intubation on the association between patent ductus arteriosus and bronchopulmonary dysplasia (grades 2 and 3)

OBJECTIVE

To determine if the need for mechanical ventilation alters the association between prolonged patent ductus arteriosus (PDA) exposure and bronchopulmonary dysplasia (grades 2 and 3) (BPD).

STUDY DESIGN

Observational study of 407 infants (<28 weeks' gestation) with echocardiograms performed at planned intervals.

RESULTS

Twelve percent (48/407) of study infants had BPD (grades 2 and 3). In a multivariable regression model, exposure to a moderate-to-large PDA shunt for ≥7 days was associated with an increased risk of BPD (grades 2 and 3) (from 16 to 35%: aRD = 19% (6, 32%), p < 0.005) when infants required ≥10 days of intubation (n = 170). In contrast, there was no significant association between prolonged PDA exposure and BPD when infants required ≤9 days of intubation (aRD = 4%) (-1, 10%) (n = 237).

CONCLUSIONS

Moderate-to-large PDAs are associated with an increased risk of BPD-but only when infants require intubation ≥10 days.