Mandatory Closure Versus Nonintervention for Patent Ductus Arteriosus in Very Preterm Infants

Early versus late caffeine and/or non-steroidal anti-inflammatory drugs (NSAIDS) for prevention of intermittent hypoxia-induced neuroinflammation in the neonatal rat

Preterm infants often experience frequent intermittent hypoxia (IH) episodes which are associated with neuroinflammation. We tested the hypotheses that early caffeine and/or non-steroidal inflammatory drugs (NSAIDs) confer superior therapeutic benefits for protection against IH-induced neuroinflammation than late treatment. Newborn rats were exposed to IH or hyperoxia (50% O2) from birth (P0) to P14. For early treatment, the pups were administered: 1) daily caffeine (Caff) citrate (Cafcit, 20 mg/kg IP loading on P0, followed by 5 mg/kg from P1-P14); 2) ketorolac (Keto) topical ocular solution in both eyes from P0 to P14; 3) ibuprofen (Ibu, Neoprofen, 10 mg/kg loading dose on P0 followed by 5 mg/kg/day on P1 and P2); 4) Caff+Keto co-treatment; 5) Caff+Ibu co-treatment; or 6) equivalent volume saline (Sal). On P14, animals were placed in room air (RA) with no further treatment until P21. For late treatment, pups were exposed from P0 to P14, then placed in RA during which they received similar treatments from P15-P21 (Sal, Caff, and/or Keto), or P15-P17 (Ibu). RA controls were similarly treated. At P21, whole brains were assessed for histopathology, apoptosis, myelination, and biomarkers of inflammation. IH caused significant brain injury and hemorrhage, inflammation, reduced myelination, and apoptosis. Early treatment with Caff alone or in combination with NSAIDs conferred better neuroprotection against IH-induced damage than late treatment. Early postnatal treatment during a critical time of brain development, may be preferable for the prevention of IH-induced brain injury in preterm infants.

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.

Analysis of perinatal risk factors for massive pulmonary hemorrhage in very low birth weight infant: A nationwide large cohort database

OBJECTIVE

To determine perinatal risk factors for Massive pulmonary hemorrhage (MPH) and MPH-caused mortality to guide clinicians in implementing preventive measures at the beginning of life for improving the survival of very low birth weight infant (VLBWIs).

STUDY DESIGN

A total of 13,826 VLBWIs born between 2013 and 2020 in the Korean Neonatal Network database were included.

RESULTS

MPH occurred in 870 (6.3 %) VLBWIs. Among infants with MPH, 162 (18.6 %) VLBWIs died due to MPH. In the multivariate logistic regression analysis, independent risk factors for MPH were identified as small for gestational age, multiple gestation, high CRIB-II score, use of surfactant, and symptomatic patent ductus arteriosus (sPDA) in VLBIWs. Independent risk factors for MPH-caused mortality were identified as multiple gestation in VLBWIs. Receiving a complete course of antenatal corticosteroids (ACS) was found to be a significant independent protective factor for MPH-caused mortality in VLBWIs.

CONCLUSION

Proactive managements for reducing unnecessary use of pulmonary surfactant and for decreasing the risk of sPDA at the beginning of life could be recommended as preventive strategies to reduce the risk of MPH in extremely preterm infants. ACS therapy is highly recommended for women with a high likelihood of giving birth preterm to reduce the risk of mortality caused by MPH.

Transcatheter closure of patent ductus arteriosus in preterm infants: results from a single-center cohort

Objective

To assess the success rate of patent ductus arteriosus (PDA) transcatheter closure in preterm infants and to describe the nature of procedural adverse events and short-term clinical status.

Study design

All the preterm infants with PDA transcatheter closure were evaluated retrospectively between July 2019 and March 2023 in a single level III neonatal intensive care unit in France. The procedure was performed in the catheterization laboratory using venous canulation. We retrospectively collected data about the patients' characteristics, procedural outcomes and complications.

Results

Twenty-five infants born between 23.4 and 32.0 weeks of gestational age (mean ± SD 26.3 ± 1.9 weeks) underwent transcatheter PDA closure. Their mean age and weight at the time of the procedure were 52 days (range 22-146 days) and 1,620 g (range 890-3,700 g), respectively. Successful closure was achieved in all but one patient. Procedure related complications were reported in 10 infants (40%), including 6 left pulmonary artery stenosis one of which required a balloon dilatation, two cardiac tamponades and two inferior vena cava thrombosis. Only two post-ligature syndromes occurred after the procedure. Two infants died one of which was related to the procedure.

Conclusion

Transcatheter closure of a PDA is a valid alternative to surgical ligation due to its high success rate and low incidence of post-ligature syndrome. Nevertheless, we also report rare, although serious complications.

Machine learning predictive models for grading bronchopulmonary dysplasia: umbilical cord blood IL-6 as a biomarker

Objectives

This study aimed to analyze the predictive value of umbilical cord blood Interleukin-6 (UCB IL-6) for the severity-graded BPD and to establish machine learning (ML) predictive models in a Chinese population based on the 2019 NRN evidence-based guidelines.

Methods

In this retrospective analysis, we included infants born with gestational age <32 weeks, who underwent UCB IL-6 testing within 24 h of admission to our NICU between 2020 and 2022. We collected their medical information encompassing the maternal, perinatal, and early neonatal phases. Furthermore, we classified the grade of BPD according to the 2019 NRN evidence-based guidelines. The correlation between UCB IL-6 and the grades of BPD was analyzed. Univariate analysis and ordinal logistic regression were employed to identify risk factors, followed by the development of ML predictive models based on XGBoost, CatBoost, LightGBM, and Random Forest. The AUROC was used to evaluate the diagnostic value of each model. Besides, we generated feature importance distribution plots based on SHAP values to emphasize the significance of UCB IL-6 in the models.

Results

The study ultimately enrolled 414 preterm infants, with No BPD group (n = 309), Grade 1 BPD group (n = 73), and Grade 2-3 BPD group (n = 32). The levels of UCB IL-6 increased with the grades of BPD. UCB IL-6 demonstrated clinical significance in predicting various grades of BPD, particularly in distinguishing Grade 2-3 BPD patients, with an AUROC of 0.815 (95% CI: 0.753-0.877). All four ML models, XGBoost, CatBoost, LightGBM, and Random Forest, exhibited Micro-average AUROC values of 0.841, 0.870, 0.851, and 0.878, respectively. Notably, UCB IL-6 consistently appeared as the most prominent feature across the feature importance distribution plots in all four models.

Conclusion

UCB IL-6 significantly contributes to predicting severity-graded BPD, especially in grade 2-3 BPD. Through the development of four ML predictive models, we highlighted UCB IL-6's importance.

Trends in Procedural Closure of the Patent Ductus Arteriosus among Infants Born at 22 to 30 Weeks' Gestation

OBJECTIVE

To describe recent trend in procedural closure of the patent ductus arteriosus (PDA) among premature infants and compare the clinical characteristics of infants receiving surgical vs transcatheter closure.

STUDY DESIGN

We conducted a descriptive, retrospective cohort study of preterm infants born between 220/7 and 296/7 weeks' gestation from 2014 through 2021. Infants were identified from the Pediatrix Clinical Data Warehouse. We excluded infants with any major congenital anomaly. We identified all preterm infants with a PDA and all those who underwent procedural closure (surgical ligation or transcatheter occlusion) and compared changes over time using ANOVA for continuous variables and the Cochran-Armitage trend test to evaluate time-related changes in proportions.

RESULTS

The study cohort included 64 580 infants, of whom 24 028 (37.2%) were diagnosed with a PDA. The number of infants receiving any procedural closure of the PDA decreased from 371 (4.4%) in 2014 to 144 (1.9%) in 2021. During the same period, number of surgical ligations decreased from 369 (4.36%) to 64 (0.84%), and the number of transcatheter occlusions increased from 2 (0.02%) to 80 (1.05% p for all < 0.001). The median age at time of surgical ligation increased from 25 days (10th and 90th percentile, 10, 61) to 31 days (10th and 90th percentile, 16, 66), and the median age of transcatheter occlusion decreased from 103 days (10th and 90th percentile, 32, 150) to 43 days (10th and 90th percentile, 22, 91).

CONCLUSIONS

There was a decrease in surgical closure and an increase in transcatheter occlusion of the PDA in infants born at 22-30 weeks' gestation from 2014 to 2021. Despite the decline in overall procedural closure, the rate of transcatheter occlusion surpassed surgical ligation by 2021. Narrowing differences in the median age and weight at closure suggest increasing overlap in the types of infants who received each type of procedural closure.

Outpatient prescription of pulmonary vasodilator therapy to preterm children with bronchopulmonary dysplasia

AIM

The use of pulmonary vasodilator therapy in children born preterm is largely unknown. Our aim was to map prescription patterns in children with bronchopulmonary dysplasia in Sweden.

METHODS

This was a descriptive national registry-based study of children <7 years who had been prescribed a pulmonary vasodilator during 2007-2017, were born preterm and classified as having bronchopulmonary dysplasia. Information on prescriptions, patient characteristics and comorbidities were retrieved from the Swedish Prescribed Drug Register and linked to other national registers.

RESULTS

The study included 74 children, 54 (73%) born at 22-27 weeks' gestation and 20 (27%) at 28-36 weeks. Single therapy was most common, n = 64 (86.5%), and sildenafil was prescribed most frequently, n = 69 (93%). Bosentan, iloprost, macitentan and/or treprostinil were used mainly for combination therapies, n = 10 (13.5%). Patent ductus arteriosus or atrial septal defect were present in 29 (39%) and 25 (34%) children, respectively, and 20 (69%) versus 3 (12%) underwent closure. Cardiac catheterisation was performed in 19 (26%) patients. Median duration of therapy was 4.6 (1.9-6.8, 95% CI) months. Mortality was 9%.

CONCLUSION

Preterm children with bronchopulmonary dysplasia were prescribed pulmonary vasodilators, often without prior catheterisation. Sildenafil was most commonly used. Diagnostic tools, effects, and drug safety need further evaluation.

Predictors of a non-response to prophylactic indomethacin for patent ductus arteriosus in preterm infants

BACKGROUND

Preterm infants are recommended for prophylactic indomethacin (PIND) to promote closure of patent ductus arteriosus (PDA) and reduce morbidity and mortality. This study investigated the predictive factors of a non-response to PIND for PDA in preterm-birth infants.

METHODS

Consecutive preterm-birth infants (gestational age: < 28 weeks) who received PIND between 2009 and 2019 were retrospectively enrolled. Seventy-six eligible participants were classified as PIND responders (N = 42) or non-responders (N = 34). Information on potential confounders in maternal obstetric and perinatal data were collected from medical records. Multiple logistic regression analysis was carried out to identify the prognostic factors of a PIND response in preterm-birth infants.

RESULTS

The prevalence of intrauterine infection and multiple births was significantly different between responders and non-responders to PIND (intrauterine infection: 2 [4.8%] vs. 8 [23.5%], P = 0.036; twins: 3 [7.1%] vs. 9 [ 26.5%], P = 0.029, respectively). In multivariate logistic regression analysis after adjustment for multiple births, intrauterine infection was a significant and independent predictive factor of a non-response to PIND (odds ratio [OR] 5.54, 95% confidence interval [CI] 1.05-29.2, P = 0.044). A remarkable association was also noted for multiple births with a non-response to PIND (OR 4.22, 95% CI 0.99-17.8, P = 0.050).

CONCLUSIONS

Intrauterine infection and multiple births were identified as potential risk factors of a non-response to PIND for PDA in preterm infants.

Outcomes of and factors associated with the development of bronchopulmonary dysplasia with pulmonary hypertension in very low birth weight infants: A retrospective study in a medical center

Introduction

Bronchopulmonary dysplasia (BPD) with pulmonary hypertension (PH) leads to increased morbidity and mortality in extremely preterm infants. Recent studies have analyzed factors associated with development of PH in BPD; however, this research remains inconclusive, and controversy exists regarding the correlation between BPD and PH. This study aimed to investigate potential associated factors, clinical characteristics, and outcomes of BPD with pulmonary hypertension in very low birth weight (VLBW) preterm infants.

Methods

We conducted a retrospective study, reviewing the records of infants with gestational age (GA) <32 weeks and birth weight <1,500 g admitted to a tertiary neonatal intensive care unit between January 2020 and October 2021 who were diagnosed with moderate to severe BPD. Echocardiogram was performed at the postmenstrual age of 36 weeks or before discharge. The diagnosis of PH was based on the findings of echocardiogram. Prenatal and postnatal characteristics, demographic data, treatment details, and outcomes were collected and analyzed.

Results

A total of 139 VLBW infants with BPD were enrolled and divided into a PH group (n = 25) and a non-PH group (n = 114). The mean GA was 27.3 ± 2.3 weeks and the mean birth weight of infants with BPD was 927.3 ± 293.3 g. A multivariate logistic regression model revealed that a high positive end-expiratory pressure (PEEP) setting (OR: 2.105; 95% CI: 1.472-3.011; p < 0.001) in established BPD and surgical closure of patent ductus arteriosus (PDA; OR: 6.273; 95% CI: 1.574-24.977; p = 0.009) were associated with BPD-PH. Neonates with BPD who developed pulmonary hypertension remained hospitalized for longer (p < 0.001), received invasive mechanical ventilation support for longer (p < 0.001), had a higher incidence of retinopathy of prematurity (ROP; OR: 4.201; 95% CI: 1.561-11.304; p = 0.003), were more likely to require oxygen support at discharge (OR: 5.600; 95% CI: 2.175-14.416; p < 0.001), and were more likely to undergo tracheostomy (OR: 35.368; 95% CI: 4.03-310.43; p < 0.001).

Conclusion

PDA ligation and a higher PEEP setting were associated with BPD-PH in our cohort study. Compared with VLBW infants with BPD but without PH, infants with BPD and PH were hospitalized for longer, and also had a higher incidence of oxygen support after discharge, ROP, and tracheostomy.

Conservative Management of Patent Ductus Arteriosus Is Feasible in the Peri-Viable Infants at 22-25 Gestational Weeks

The purpose of this study was to determine the natural course of hemodynamically significant (HS) patent ductus arteriosus (PDA) with conservative management and whether the presence or prolonged duration of HS PDA affected mortality/morbidities in infants at 22-25 weeks estimated gestational age (EGA). We retrospectively reviewed the medical records of 77 infants born at 22-25 weeks EGA, stratified into 22-23 weeks (n = 21) and 24-25 weeks EGA (n = 56). HS PDA was present in 77%, 76%, and 77%, and open ductus at discharge was 12%, 13%, and 12% in the total and at 22-23 and 24-25 weeks EGA infants, respectively. For backup rescue treatment, 7% and 5% of the infants received oral ibuprofen and device closure, respectively. A mortality rate of 9% was found in the HS PDA (+) infants, significantly lower than the 28% in HS PDA (-) infants. There are no significant differences in morbidities. In multivariate analyses, the presence and/or prolonged duration of HS PDA was not associated with increased mortality or morbidity. Spontaneous closure of HS PDA was achieved through conservative management in the peri-viable infants at 22-25 weeks EGA.

Paracetamol (acetaminophen) for patent ductus arteriosus in preterm or low birth weight infants

BACKGROUND

The different management strategies for patent ductus arteriosus (PDA) in preterm infants are expectant management, surgery, or medical treatment with non-selective cyclo-oxygenase inhibitors. Randomized controlled trials (RCTs) have suggested that paracetamol may be an effective and safe agent for the closure of a PDA.

OBJECTIVES

To determine the efficacy and safety of paracetamol as monotherapy or as part of combination therapy via any route of administration, compared with placebo, no intervention, or another prostaglandin inhibitor, for prophylaxis or treatment of an echocardiographically-diagnosed PDA in preterm or low birth weight infants.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, and three trials registers on 13 October 2021, and one other database on 1 March 2022. We also checked references and contacted study authors to identify additional studies.

SELECTION CRITERIA

We included RCTs and quasi-RCTs in which paracetamol (single-agent or combination therapy) was compared to no intervention, placebo, or other agents used for closure of PDA, irrespective of dose, duration, and mode of administration in preterm infants. Two independent authors reviewed the search results and made a final selection of potentially eligible articles through discussion.

DATA COLLECTION AND ANALYSIS

We performed data collection and analyses in accordance with the methods of Cochrane Neonatal. We used the GRADE approach to assess the certainty of evidence for the following outcomes: failure of ductal closure after the first course of treatment; all-cause mortality during initial hospital stay; and necrotizing enterocolitis (NEC).

MAIN RESULTS

For this update, we included 27 studies enrolling 2278 infants. We considered the overall risk of bias in the 27 studies to vary from low to unclear. We identified 24 ongoing studies. Paracetamol versus ibuprofen  There was probably little to no difference between paracetamol and ibuprofen for failure of ductal closure after the first course (risk ratio (RR) 1.02, 95% confidence interval (CI) 0.88 to 1.18; 18 studies, 1535 infants; moderate-certainty evidence). There was likely little to no difference between paracetamol and ibuprofen for all-cause mortality during hospital stay (RR 1.09, 95% CI 0.80 to 1.48; 8 studies, 734 infants; moderate-certainty evidence), and for NEC (RR 1.30, 95% CI 0.87 to 1.94; 10 studies, 1015 infants; moderate-certainty evidence). Paracetamol versus indomethacin There was little to no difference between paracetamol and indomethacin for failure of ductal closure after the first course (RR 1.02, 95% CI 0.78 to 1.33; 4 studies, 380 infants; low-certainty evidence). There was little to no difference between paracetamol and indomethacin for all-cause mortality during hospital stay (RR 0.86, 95% CI 0.39 to 1.92; 2 studies, 114 infants; low-certainty evidence). The rate of NEC may be lower in the paracetamol group (3.7%) versus the indomethacin group(9.2%) (RR 0.42, 95% CI 0.19 to 0.96; 4 studies, 384 infants; low-certainty evidence).  Prophylactic paracetamol versus placebo/no intervention Prophylactic paracetamol (17%) compared to placebo/no intervention (61%) may reduce failure of ductal closure after one course (RR 0.27, 95% CI 0.18 to 0.42; 3 studies, 240 infants; low-certainty evidence). There was little to no difference between prophylactic paracetamol and placebo/no intervention for all-cause mortality during hospital stay (RR 0.59, 95% CI 0.24 to 1.44; 3 studies, 240 infants; low-certainty evidence). No studies reported on NEC.  Early paracetamol treatment versus placebo/no intervention Early paracetamol treatment (28%) compared to placebo/no intervention (79%) may reduce failure of ductal closure after one course when used before 14 days' postnatal age (RR 0.35, 95% CI 0.23 to 0.53; 2 studies, 127 infants; low-certainty evidence). No studies reported on all-cause mortality during hospital stay or NEC.  Late paracetamol treatment versus placebo/no intervention  There was little to no difference between late paracetamol and placebo for failure of ductal closure after one course of treatment when used at or after 14 days' postnatal age (RR 0.85, 95% CI 0.72 to 1.01; 1 study, 55 infants; low-certainty evidence) or NEC (RR 1.04, 95% CI 0.07 to 15.76; 1 study, 55 infants; low-certainty evidence). No data were reported for all-cause mortality during hospital stay.  Paracetamol combined with ibuprofen versus ibuprofen combined with placebo or no intervention There was little to no difference between paracetamol plus ibuprofen compared to ibuprofen plus placebo or no intervention for failure of ductal closure after the first course (RR 0.77, 95% CI 0.43 to 1.36; 2 studies, 111 infants; low-certainty evidence). There was little to no difference between paracetamol plus ibuprofen compared to ibuprofen plus placebo or no intervention for NEC (RR 0.33, 95% CI 0.01 to 7.45; 1 study, 24 infants; low-certainty evidence). No data were reported for all-cause mortality during hospital stay.  AUTHORS' CONCLUSIONS: Moderate-certainty evidence suggests that there is probably little or no difference in effectiveness between paracetamol and ibuprofen; low-certainty evidence suggests that there is probably little or no difference in effectiveness between paracetamol and indomethacin; low-certainty evidence suggests that prophylactic paracetamol may be more effective than placebo/no intervention; low-certainty evidence suggests that early paracetamol treatment may be more effective than placebo/no intervention; low-certainty evidence suggests that there is probably little or no difference between late paracetamol treatment and placebo, and probably little or no difference in effectiveness between the combination of paracetamol plus ibuprofen versus ibuprofen alone for the closure of PDA after the first course of treatment. The majority of neonates included in these studies were of moderate preterm gestation. Thus, establishing the efficacy and safety of paracetamol for PDA treatment in extremely low birth weight (ELBW: birth weight < 1000 grams) and extremely low gestational age neonates (ELGANs < 28 weeks' gestation) requires further studies.

Comparison of neonatal morbidity and mortality between single-room and open-bay care: a retrospective cohort study

OBJECTIVE

In response to the increasing focus on family-centred care, neonatal intensive care unit (NICU) environments have gradually shifted towards the single-room design. However, the assumed benefits of this emerging design remain a subject of debate. Our goal was to evaluate the impact of single-room versus open-bay care on the risk of neonatal morbidity and mortality in preterm neonates.

DESIGN

Retrospective cohort study.

SETTING

Level III NICU.

PATIENTS

Neonates born <32 weeks' gestation between 15 May 2015 and 15 May 2019.

MAIN OUTCOME MEASURES

Mortality and morbidities of a cohort of neonates admitted to a new, single-room unit (SRU) were compared with a historical cohort of neonates admitted to an open-bay unit (OBU). Group differences were evaluated and multivariable logistic regression analyses were performed.

RESULTS

Three-hundred and fifty-six and 343 neonates were admitted to the SRU and OBU, respectively. No difference in neonatal morbidities and mortality were observed between cohorts (bronchopulmonary dysplasia: OR 1.08, 95% CI 0.73 to 1.58, p=0.44; retinopathy of the prematurity stage ≥2: OR 1.36, 95% CI 0.84 to 2.22, p=0.10; intraventricular haemorrhage: OR 0.89, 95% CI 0.59 to 1.34, p=0.86; mortality: OR 1.55, 95% CI 0.75 to 3.20, p=0.28). In adjusted regression models, single-room care was independently associated with a decreased risk of symptomatic patent ductus arteriosus (adjusted OR 0.54, 95% CI 0.31 to 0.95). No independent association between single-room care and any of the other investigated outcomes was observed.

CONCLUSIONS

Implementation of single-rooms in our NICU did not lead to a significant reduction in neonatal morbidity and mortality outcomes.

International Variation in the Management of Patent Ductus Arteriosus and Its Association with Infant Outcomes: A Survey and Linked Cohort Study

OBJECTIVE

To assess whether treating patients with a presymptomatic patent ductus arteriosus (PDA), based on early routine echocardiography, performed regardless of clinical signs, improved outcomes.

STUDY DESIGN

This multicenter, survey-linked retrospective cohort study used an institutional-level questionnaire and individual patient-level data and included infants of <29 weeks of gestation born in 2014-2016 and admitted to tertiary neonatal intensive care units (NICUs) of 9 population-based national or regional neonatal networks. Infants in NICUs receiving treatment of presymptomatic PDA identified by routine echocardiography and those not were compared for the primary composite outcome (early death [≤7 days after birth] or severe intraventricular hemorrhage) and secondary outcomes (any in-hospital mortality and major morbidities).

RESULTS

The unit survey (response rates of 86%) revealed a wide variation among networks in the treatment of presymptomatic PDA (7%-86%). Among 246 NICUs with 17 936 infants (mean gestational age of 26 weeks), 126 NICUs (51%) with 7785 infants treated presymptomatic PDA. The primary outcome of early death or severe intraventricular hemorrhage was not significantly different between the NICUs treating presymptomatic PDA and those who did not (17% vs 21%; aOR 1.00, 95% CI 0.85-1.18). The NICUs treating presymptomatic PDA had greater odds of retinopathy of prematurity treatment (13% vs 7%; aOR 1.47, 95% CI 1.01-2.12); however, it was not significant in a sensitivity analysis excluding Japanese data.

CONCLUSIONS

Treating presymptomatic PDA detected by routine echocardiography was commonplace but associated with no significant benefits. Well-designed trials are needed to assess the efficacy and safety of early targeted PDA treatment.

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.

Trend and Outcomes for Surgical Versus Transcatheter Patent Ductus Arteriosus Closure in Neonates and Infants at US Children's Hospitals

Background Pharmacologic therapy for patent ductus arteriosus closure is not consistently successful. Surgical ligation (SL) or transcatheter closure (TC) may be needed. Large multicenter analyses comparing outcomes and resource use between SL and TC are lacking. We hypothesized that patients undergoing TC have improved outcomes compared with SL, including mortality, hospital and intensive care unit length of stay, and mechanical ventilation. Methods and Results Using the 2016 to 2020 Pediatric Health Information System database, characteristics, outcomes, and charges of patients aged <1 year who underwent TC or SL were analyzed. A total of 678 inpatients undergoing TC (n=503) or SL (n=175) were identified. Surgical patients were younger (0.1 versus 0.53 years; P<0.001) and more premature (60% versus 20.3%; P<0.001). Surgical patients had higher mortality (1.7% versus 0%; P=0.02). Using inverse probability of treatment weighting by the propensity score, multivariable-adjusted analyses demonstrated favorable outcomes in TC: intensive care unit admission rates (adjusted odds ratio [OR], 0.2; 95% CI, 0.11-0.32; P<0.001); mechanical ventilation rates (adjusted OR, 0.3; 95% CI, 0.19-0.56; P<0.001); and shorter hospital (adjusted coefficient, 2 days shorter; 95% CI, 1.3-2.7; P<0.001) and postoperative (adjusted coefficient, 1.2 days shorter; 95% CI, 0.1-2.3; P=0.039) stays. Overall charges and readmission rates were similar. Among premature neonates and infants, hospital (adjusted difference in medians, 4 days; 95% CI, 1.7-6.3 days; P<0.001) and postoperative stays (adjusted difference in medians, 3 days; 95% CI, 1.1-4.9 days; P=0.002) were longer for SL. Conclusions TC is associated with lower mortality and reduced length of stay compared with SL. Rates of TC continue to increase compared with SL.

Outcomes among preterm infants with patent ductus arteriosus: Relationship with treatment, gestational age, hemodynamic status and timing of treatment

BACKGROUND

There remains controversy regarding the outcomes resulting from treatment versus conservative management of patent ductus arteriosus (PDA) among preterm infants. The effects of extreme prematurity, hemodynamic status of the PDA, and age at treatment remain poorly defined.

STUDY DESIGN

This retrospective case-control study including infants <  1250 gm who were categorized into 3 groups: Group 1: without PDA, Group 2: with untreated PDA, and Group 3: treated PDA. Diagnosis and treatment of PDA extracted from the medical records. Demographics, clinical characteristics, and outcomes compared using chi-square and analysis of variance. Logistic regression used to estimate adjusted odds ratios.

RESULTS

The study included 734 infants, with 141(19%) in Group 1, 329 (45%) in 2, and 264 (36%) in 3. Group 3 had higher incidence of bronchopulmonary dysplasia (BPD) (aOR, 2.9; 95%CI 1.7-4.8). Infant treated for hemodynamically significant PDA (HSPDA) had higher incidence of BPD (aOR, 1.9; 95%CI 1.0-3.8) and retinopathy of prematurity (ROP) (aOR, 3.4; 95%CI 1.6-6.9). There were no differences in outcome associated with treatment among≤26 weeks gestation and the age when treated.

CONCLUSION

Infants with PDA who were treated had higher incidence of BPD. Among those who were treated, those with HSPDA had a higher incidence of BPD and ROP.

Discriminant Analysis of Main Prognostic Factors Associated with Hemodynamically Significant PDA: Apgar Score, Silverman-Anderson Score, and NT-Pro-BNP Level

Hemodynamically significant patent ductus arteriosus (hsPDA) in premature newborns is associated with a risk of PDA-related morbidities. Classification into risk groups may have a clinical utility in cases of suspected hsPDA to decrease the need for echocardiograms and unnecessary treatment. This prospective observational study included 99 premature newborns with extremely low body weight, who had an echocardiogram performed within the first three days of life. Discriminant analysis was utilized to find the best combination of prognostic factors for evaluation of hsPDA. We used binary logistic regression analysis to predict the relationship between parameters and hsPDA. The cohort's mean and standard deviation gestational age was 27.6 ± 2.55 weeks, the mean birth weight was 1015 ± 274 g. Forty-six (46.4%) infants had a PDA with a mean diameter of 2.78 mm. Median NT-pro-BNP levels were 17,600 pg/mL for infants with a PDA and 2773 pg/mL in the non-hsPDA group. The combination of prognostic factors of hsPDA in newborns of extremely low body weight on the third day of life was determined: NT-pro-BNP, Apgar score, Silverman-Anderson score (Se = 82%, Sp = 88%). A cut-off value of NT-pro-BNP of more than 8500 pg/mL can predict hsPDA (Se = 84%, Sp = 86%).

An Update on the Prevention and Management of Bronchopulmonary Dysplasia

Bronchopulmonary dysplasia (BPD) is a common morbidity affecting preterm infants and is associated with substantial long-term disabilities. There has been no change in the incidence of BPD over the past 20 years, despite improvements in survival and other outcomes. The preterm lung is vulnerable to injuries occurring as a result of invasive ventilation, hyperoxia, and infections that contribute to the development of BPD. Clinicians caring for infants in the neonatal intensive care unit use multiple therapies for the prevention and management of BPD. Non-invasive ventilation strategies and surfactant administration via thin catheters are treatment approaches that aim to avoid volutrauma and barotrauma to the preterm developing lung. Identifying high-risk infants to receive postnatal corticosteroids and undergo patent ductus arteriosus closure may help to individualize care and promote improved lung outcomes. In infants with established BPD, outpatient management is complex and requires coordination from several specialists and therapists. However, most current therapies used to prevent and manage BPD lack solid evidence to support their effectiveness. Further research is needed with appropriately defined outcomes to develop effective therapies and impact the incidence of BPD.

Outcomes of Extremely Premature Infants Comparing Patent Ductus Arteriosus Management Approaches

OBJECTIVE

To evaluate the change in the proportion of deaths/bronchopulmonary dysplasia (BPD) among premature infants (born <26 and 26-29 weeks of gestational age) following a policy change to a strict nonintervention approach, compared with standard treatment.

STUDY DESIGN

We examined 1249 infants (341 born <26 weeks of gestational age) at 2 comparable sites. Site 1 (control) continued medical treatment/ligation, and site 2 (exposed) changed to a nonintervention policy in late 2013. Using the difference-in-differences approach, which accounts for time-invariant differences between sites and secular trends, we assessed changes in death or BPD separately among infants born 26-29 weeks and <26 weeks of gestational age in 2 epochs (epoch 1: 2011-2013; epoch 2: 2014-2017).

RESULTS

Baseline characteristics were similar across sites and epochs. Medical treatment/ligation use remained stable at site 1 but declined progressively to 0% at site 2, indicating adherence to policy. We saw no difference in death/BPD among infants born at 26-29 weeks of gestational age (12%, 95% CI -1% to 24%). However, incidence of death/BPD increased by 31% among infants born <26 weeks of gestational age (95% CI 10%-51%) in site 2, whereas there was no change in outcomes in site 1. The Score for Neonatal Acute Physiology-Version II, used as a control outcome, did not change in either site, suggesting that our findings were not due to changes in patients' severity.

CONCLUSIONS

Adherence to a strict conservative policy did not impact death or BPD among 26 weeks but was associated with a significant rise in infants born <26 weeks.

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.

Early pulmonary hypertension is a risk factor for bronchopulmonary dysplasia-associated late pulmonary hypertension in extremely preterm infants

This study evaluated whether early pulmonary hypertension (PH) in extremely preterm infants (EPIs) at 22–27 weeks of gestation detected clinically with echocardiography at 4–7 postnatal days (PND) is a risk factor for death before 36 weeks post-menstrual age (PMA) or late PH in moderate or severe (m/s) bronchopulmonary dysplasia (BPD) (BPD-PH). We analyzed risk factors for death before 36 weeks PMA or BPD-PH. Among 247 EPIs enrolled, 74 (30.0%) had early PH. Twenty-one (28.4%) infants with early PH and 18 (10.4%) without early PH died before 36 weeks PMA; 14 (18.9%) infants with early PH and 9 (5.2%) without early PH had BPD-PH at 36–38 weeks PMA. Multivariate analysis revealed that early PH (adjusted odds ratio, 6.55; 95% confidence interval, 3.10–13.82, P < 0.05), clinical chorioamnionitis (2.50; 1.18–5.31), intraventricular hemorrhage (grade 3–4) (3.43; 1.26–9.37), and late sepsis (6.76; 3.20–14.28) independently increased the risk of development of death before 36 weeks PMA or BPD-PH. Subgroup analysis among m/s BPD patients revealed that early PH (4.50; 1.61–12.58) and prolonged invasive ventilator care (> 28 days) (4.91; 1.02–23.68) increased the risk for late PH independently. In conclusion, EPIs with early PH at 4–7 PND should be monitored for BPD-associated late PH development.

Patent ductus arteriosus treatment trends and associated morbidities in neonates

To evaluate national epidemiologic data on infants treated for patent ductus arteriosus (PDA) in Korea and analyze outcomes associated with different PDA treatments. We retrospectively evaluated data on 12,336 patients diagnosed with PDA (International Classification of Diseases-10 code: Q250) between 2015 and 2018 from the Health Insurance Review and Assessment database. Among them, 1623 patients underwent surgical ligation (code: O1671). We used birth certificate data from Statistics Korea to estimate the prevalence, diagnosis, and treatment of PDA. The prevalence of infants with PDA was 81 infants per 10,000 live births and 45.2% in very low birth weight (VLBW) infants, which increased from 2015 to 2018. PDA ligation was performed in 2571 infants and 22% VLBW infants. Medical treatment was administered to 4202 infants, which decreased significantly, especially in VLBW infants (62% to 53%). The proportion of treatment was as follows: conservative treatment (53.1%), intravenous ibuprofen (24.4%), surgery (20.4%), and oral ibuprofen (10.7%); that among 4854 VLBW infants was as follows: intravenous ibuprofen (46.3%), conservative treatment (33.2%), surgery (22.2%), and oral ibuprofen (14.2%). Surgical treatment had a significantly higher risk (odds ratio 1.36) of mortality than conservative treatment. Surgical and/or medical treatments were associated with a higher risk of morbidity. Recently, increased use of conservative management of PDA has contributed to improved neonatal outcomes in VLBW infants. Select patients may still benefit from surgical ligation following careful consideration.

Short-Term Complications Associated with Surgical Ligation of Patent Ductus Arteriosus in ELBW Infants: A 25-Year Cohort Study

OBJECTIVE

This article aims to determine the incidence of short-term complications of surgical patent ductus arteriosus (PDA) ligations, the factors associated with those complications, and whether complications are associated with poor long-term outcomes.

STUDY DESIGN

Retrospective cohort study of all extremely low birth weight (ELBW, < 1,000 g) infants who underwent surgical PDA ligation at a single-center neonatal intensive care unit from 1989 to 2015. Demographic, clinical, and laboratory data were reviewed. The primary outcome was development of a short-term (< 2 weeks from ligation) surgical complication. Secondary outcomes include bronchopulmonary dysplasia (BPD), length of stay, and mortality.

RESULTS

A total of 180 ELBW infants were included; median gestational age and birth weight was 24 weeks and 683 g, respectively, and 44% of infants had at least one short-term complication. Need for vasopressors (33%) was the most common medical complication and vocal cord paralysis (9%) was the most common surgical complication. Younger corrected gestational age at time of repair was associated with increased risk for complications. Mortality, length of stay, and BPD rates were similar between infants with and without complications.

CONCLUSION

Serious complications were seen in a minority of infants. Additional research is needed to determine if short-term complications are associated with long-term adverse outcomes.

Patent ductus arteriosus management and the drift towards therapeutic nihilism - What is the evidence?

The published literature on patent ductus arteriosus (PDA) management is challenging to interpret due to poorly designed trials with high rates of open label treatments, homogenisation of patients with varying physiological subtypes, poor treatment efficacy, and spontaneous closure in more mature infants. The perceived lack of clinical benefit has led to a drift away from medical and surgical treatment of all infants with a PDA. This therapeutic nihilism as a default response to PDA management fails to recognise the physiological relevance of a left-to-right shunt with early haemodynamic instability after birth and subsequent pulmonary volume overload with prolonged exposure. Clinicians need to know if therapeutic nihilism is safe. This review will provide an overview of the available data on the efficacy of known PDA treatments, conservative management and supportive care measures that are currently applied.

Neurodevelopmental Impairment at Two Years in Premature Infants with Prolonged Patency of Ductus Arteriosus after a Conservative Approach

OBJECTIVE

The study aims to assess the impact on neurodevelopmental outcomes of a prolonged hemodynamically significant patent ductus arteriosus (PDA) after a conservative treatment.

STUDY DESIGN

This involves the study of two cohorts of preterm infants 23 to 29 weeks gestation, before (n = 29) and after (n = 54) a conservative approach of PDA. We compared survival, major outcomes, and neurodevelopmental impairment (NDI) at 2 years and analyzed NDI in the conservative cohort according to the duration of the PDA.

RESULTS

Conservative cohort received less medical (31.5%) and surgical treatment (7.4%) and had more days of PDA (59 days in 24-26 weeks and 22 days in 27-29 weeks; p < 0.001) in comparison with control cohort (19 days in 24-26 weeks and 11 days in 27-29 weeks; p = 0.688). Mortality, survival-without-morbidity at discharge, and NDI at 2 years were similar between the two groups (p = 0.732). In the multivariate analysis PDA >28 days was not related to worse outcomes at discharge (p = 0.296) or less survival-without-NDI at 2 years (p = 0.498).

CONCLUSION

Until randomized trials prove the benefit of attempting to close the PDA with ibuprofen in the first week of life, conservative management may be a reasonable option.

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 Clinical Trials: Lessons Learned and Future Directions

The identification of an optimal management strategy for the patent ductus arteriosus (PDA) in the context of extreme prematurity remains elusive. Observational studies have reported a persistent association between PDA and neonatal adverse outcomes, but by and large, no clinical trial, to date, has demonstrated that treating a PDA results in a reduction of those morbidities. This discrepancy has led many to assume that the PDA is an innocent bystander in the physiological mechanisms responsible for such complications and a reluctance to actively pursue shunt elimination. It would be remiss to discount the volume of evidence available clearly documenting a strong association between longstanding PDA exposure and negative outcomes. There needs to be a radical change in the design, patient selection and possible outcome assessment in any further trials addressing the PDA. The purpose of this review is to explore the reasons that preclude existing clinical trials from definitively ascribing a causal relationship between PDA patency and adverse outcomes in the context of extreme prematurity, why previous studies have failed to demonstrate significant beneficial effects following PDA treatment and how future research may be conducted to allow us to draw concrete conclusions regarding the potential merits of ductal closure.

Morbidity associated with patent ductus arteriosus in preterm newborns: a retrospective case-control study

INTRODUCTION

Association between persistency of a patent ductus arteriosus (PDA) and morbidity in preterm newborns is still controversial. We aimed to investigate the relation between PDA and morbidity in a large retrospective study.

METHODS

A case-control study including neonates consecutively admitted to the Neonatal Intensive Care Unit (NICU), with gestational age (GA) < 32 weeks or body birth weight (BW) < 1500 g, over a 5-year period. Newborns were divided into Cases and Controls, according with the presence or absence of a hemodynamically significant PDA (hs-PDA).

RESULTS

We enrolled 85 Cases and 193 Controls. Subjects with hs-PDA had significantly (p < 0.001) lower GA (26.7 w, 95%CI 27.1-28.0 vs. 30.1 w, 95%CI 29.7-30.4), BW (1024 g, 95% CI 952-1097 vs. 1310 g 95%CI 1263-1358) and an increased morbidity (60.0% vs. 18.7%). In a sub-group of extremely preterm newborns (GA ≤ 28 weeks and BW ≤ 1000 g), the rate of bronchopulmonary dysplasia (BPD) was significantly increased in Cases (31.7%) compared with Controls (5.9%, p = 0.033). Multivariate analysis showed that morbidity significantly depended on hs-PDA, GA and BW, and that, in extremely preterms, the hs-PDA represented an independent risk factor for BPD.

CONCLUSIONS

Occurrence of the main morbidities of prematurity depended by hs-PDA, in association with GA, BW, and use of prenatal steroids. In extremely premature babies, hs-PDA is a risk factor for BPD, one of the most important morbidity of prematurity, independently by other confounding variables.

Factors affecting the effectiveness of oral ibuprofen in the treatment of patent ductus arteriosus in preterm infants

Background Data on the effectiveness of oral ibuprofen treatment for patent ductus arteriosus are limited, and the factors affecting its effectiveness remain unclear. Objective The aim was to identify the potential factors affecting the clinical effectiveness of oral ibuprofen in preterm infants. Setting Neonatal intensive care unit in a prefecture-level maternal and child healthcare hospital in China. Method Over a 5-years period, the medical records of 327 preterm infants with patent ductus arteriosus who were admitted to the neonatal intensive care unit of our hospital to receive a single course of oral ibuprofen were retrospectively reviewed. Main outcome measures The prevalence of risk factors affecting the effectiveness of oral ibuprofen. Results In total, 201 (61.47%) preterm infants were considered to have undergone "effective therapy" and classified accordingly, whereas 11 (3.36%) showed certain adverse events. Factors affecting therapeutic effectiveness were postnatal age at the initiation of treatment and Day 1/Day 0 ratio of urine output/fluid intake during the treatment course, with odds ratios of 0.892 (95% CI: 0.835-0.953; P = 0.001) and 0.473 (95% CI 0.265-0.845; P = 0.011), respectively. Conclusion A single course of oral ibuprofen for patent ductus arteriosus closure among preterm infants is effective and safe. Preterm infants with postnatal age of ≤ 9 days at the initiation of treatment and Day 1/Day 0 ratio of ≤ 0.708 of the urine output/fluid intake during the treatment course can be considered predictors of effectiveness of patent ductus arteriosus.

Conservative Management of Patent Ductus Arteriosus in Preterm Infants-A Systematic Review and Meta-Analyses Assessing Differences in Outcome Measures Between Randomized Controlled Trials and Cohort Studies

Objective: This study aims to evaluate outcome after conservative management (no pharmacological/surgical intervention other than fluid restriction, diuretics, or ventilator adjustments) compared with active (pharmacological and/or surgical) treatment for patent ductus arteriosus (PDA) in preterm infants and analyze differences in outcome between randomized controlled trials (RCTs) and cohort studies. Study Design: This is a systematic literature review using PubMed, EMBASE, and Cochrane library. RCTs and cohort studies comparing conservative management with active treatment were included. Meta-analysis was used to compare conservative management with any active (pharmacological and/or surgical), any pharmacological (non-prophylactic and prophylactic), and/or surgical treatment for mortality as primary and major neonatal morbidity as secondary outcome measure. Fixed-effect analysis was used, unless heterogeneity (I ²) was >50%. Outcome is presented as relative risk (RR) with 95% confidence interval. Results: Twelve cohort studies and four RCTs were included, encompassing 41,804 and 720 patients, respectively. In cohort studies, conservative management for PDA was associated with a significantly higher risk for mortality (RR, 1.34 [1.12-1.62]) but a significantly lower risk for bronchopulmonary dysplasia (RR, 0.55 [0.46-0.65]), necrotizing enterocolitis (RR, 0.85 [0.77-0.93]), intraventricular hemorrhage (RR, 0.88 [0.83-0.95]), and retinopathy of prematurity (RR, 0.47 [0.28-0.79]) compared with any active PDA treatment. Meta-analysis of the RCTs revealed no significant differences in outcome between conservative management and active treatment. Conclusion: No differences in mortality or morbidity for conservative management compared with active treatment regimens were observed in RCTs. Findings from cohort studies mainly highlight the lack of high-quality evidence for conservative management for PDA in preterm infants.

Development of a Nomogram for Moderate-to-Severe Bronchopulmonary Dysplasia or Death: Role of N-Terminal Pro-brain Natriuretic Peptide as a Biomarker

Objectives: This study aimed to explore the clinical value of N-terminal pro-brain natriuretic peptide (NT-proBNP) in predicting moderate-to-severe bronchopulmonary dysplasia (BPD)/death, and to establish an effective clinical predictive nomogram. Methods: We retrospectively analyzed very low birth weight infants (VLBWs) with gestational age ≤ 32 weeks. The NT-proBNP values were determined on the 1st, 3rd, 7th, 14th, 21st, and 28th days after birth. The correlation between NT-proBNP level and moderate-to-severe BPD/death was evaluated. Receiver operating characteristic (ROC) curve analysis was used to evaluate the prediction ability. Then, we used multivariable logistic regression to build the prediction model and nomogram, and calibration of the model was assessed by calibration curve. Results: In total, 556 VLBWs were involved, among whom 229 developed BPD (mild: n = 109; moderate: n = 68; severe: n = 52) and 18 died. The NT-proBNP level in the moderate-to-severe BPD/death group was significantly higher than that in the no-to-mild BPD group from the 3rd to 28th day (P < 0.001). When the natural logarithm of the serum NT-ProBNP level increased by 1 unit at day 7 (±2 days) of life, the risk of moderate and severe BPD/death was the highest (OR = 3.753; 95% CI: 2.984~4.720), and ROC analysis identified an optimal cutoff point of 3360 ng/L (sensitivity: 80.0%; specificity: 86.2%; AUC: 0.861). After adjusting for confounding factors, the level of NT-proBNP at day 7 (±2 days) of life still had important predictive value for the development of moderate-to-severe BPD/death, significantly improving the predictive ability of the model. Conclusion: The level of NT-proBNP at day 7 (±2 days) of life can be used as an early promising biomarker for VLBWs to develop moderate-to-severe BPD/death. We constructed an early predictive nomogram to help clinicians identify high-risk populations.

Conservative Treatment Without Any Intervention Compared With Other Therapeutic Strategies for Symptomatic Patent Ductus Arteriosus in Extremely Preterm Infants: A Nationwide Cohort Study in Korea

Objective: Although symptomatic treatment is the most preferred treatment strategy for proven symptomatic patent ductus arteriosus (PDA), a considerable number of infants only received conservative treatment without any pharmacological or surgical interventions in the lower gestational age and lower birth weight group in Korea. We compared in-hospital outcomes of infants treated conservatively without any intervention and those of infants managed by other therapeutic strategies in extremely preterm infants with symptomatic PDA. Methods: A prospectively collected cohort study for 2,303 infants with gestational ages <28 weeks from the Korean Neonatal Network database. These infants were classified into four groups according to the presence of PDA-related symptoms and therapeutic treatment strategy: prophylactic treatment group, pre-symptomatic treatment (PST) group, symptomatic treatment (ST) group, and conservative treatment (CT) without any intervention group. Results: In multivariable logistic regression analysis, the risk of death was significantly decreased in the PST group (adjusted odds ratio [aOR] = 0.507; 95% confidence interval [CI] 0.311-0.826) and ST group (aOR = 0.349; 95% CI: 0.230-0.529) compared with the CT group. However, the risk of composite outcome of severe bronchopulmonary dysplasia or death had not increased in the PST group and ST group. Neonatal death due to pulmonary hemorrhage or neurological disease was significantly higher in the CT group than in the PST group or ST group. Conclusion: In extremely preterm infants, who are at highest risk of PDA-related morbidities and mortality, even less interventional approach for PDA can be allowed; the rescued pharmacological or surgical interventions are necessary if they met the criteria for hemodynamically significant PDA.

Hemodynamic and clinical consequences of early versus delayed closure of patent ductus arteriosus in extremely low birth weight infants

OBJECTIVES

To describe changes in hemodynamics, respiratory support, and growth associated with transcatheter PDA closure (TCPC) in ELBW infants, stratified by postnatal age at treatment.

STUDY DESIGN

This is an observational study of ELBW infants who underwent TCPC at ≤4 weeks (Group-1; n = 34), 4-8 weeks (Group-2; n = 33), and >8 weeks of age (Group-3; n = 33). Hemodynamic assessment was performed during TCPC. Multivariate Cox-proportionate-hazard modeling was used to identify factors associated with respiratory severity score (RSS) > 2 for >30 days following TCPC.

RESULTS

In comparison with Group-1, Group-3 infants had higher pulmonary vascular resistance (PVRi = 3.3 vs. 1.6 WU*m²; P = 0.01), less weight gain between 4 and 8 weeks of age (16 vs. 25 g/day) and took longer to achieve RSS < 2 (median 81 vs. 20 days; P = 0.001). RSS > 2 for >30 days was associated with TCPC > 8 weeks (OR = 3.2, 95% CI: 1.75-5.8; p = 0.03) and PVRi ≥ 3 (OR = 4.5, 95% CI: 2.7-8.9; p < 0.01).

CONCLUSION

ELBW infants may benefit from PDA closure within the first 4 weeks of life in order to prevent early onset pulmonary vascular disease, promote faster growth, and for quicker weaning of ventilator and oxygen support.

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.

Patent ductus arteriosus and cerebral, cardiac, and gut hemodynamics in premature neonates

Patent ductus arteriosus is associated with multiple comorbidities in premature infants, however a causal link or strategy to decrease these morbidities has not been found. The association between the patent ductus arteriosus and morbidities has biologic plausibility as, like any cardiac mixing lesion, a significant systemic to pulmonic shunt may lead to pulmonary over-circulation and systemic hypoperfusion. Understanding the underlying pathophysiology of associated morbidities in the setting of a patent ductus arteriosus may aid in risk stratifying infants and offer a patient targeted approach to infants with a pathological ductal shunt. While the deleterious impact of increased pulmonary blood flow maybe easier to identify, the impact on end-organ perfusion is more challenging. In this review, we will discuss the pathophysiology of a hemodynamically significant patent ductus arteriosus in premature infants, impact on end-organ perfusion and associated morbidities, and novel modalities to assess shunt volume and effect on end-organ perfusion.

Effect of Nonintervention vs Oral Ibuprofen in Patent Ductus Arteriosus in Preterm Infants: A Randomized Clinical Trial

IMPORTANCE

Persistent patent ductus arteriosus (PDA) in preterm infants is associated with increased mortality and respiratory morbidities, including bronchopulmonary dysplasia (BPD). Despite recent increasing use of noninterventional approaches, no study to our knowledge has yet directly compared the nonintervention vs pharmacologic treatment for mediating PDA closure for decreasing mortality and preventing BPD.

OBJECTIVE

To determine the noninferiority of nonintervention vs oral ibuprofen treatment for PDA in decreasing BPD incidence or death in very preterm infants.

DESIGN, SETTING, AND PARTICIPANTS

A randomized, double-blind, placebo-controlled, noninferiority clinical trial was conducted on preterm infants (gestational age [GA] 23-30 weeks) with hemodynamically significant PDA (ductal size >1.5 mm plus respiratory support) diagnosed between postnatal days 6 and 14. Participants included 383 infants screened between July 24, 2014, and March 15, 2019.

INTERVENTIONS

Infants were stratified by GA and randomly assigned (1:1) to receive either oral ibuprofen (initial dose of 10 mg/kg followed by a 5-mg/kg dose after 24 hours and a second 5-mg/kg dose after 48 hours) or placebo.

MAIN OUTCOMES AND MEASURES

The primary outcome was BPD or death; the secondary outcomes included major morbidities and ductal closure rates. Per-protocol analysis was used.

RESULTS

Among 383 infants screened for participation, 146 infants were randomly assigned, with 72 in the nonintervention and 70 in the ibuprofen treatment group in the final analyses. The PDA closure rate at 1 week after randomization was significantly higher with ibuprofen (11 [34%]) than nonintervention (2 [7%]) in infants at GA 27 to 30 weeks (P = .007); however, the findings were not significant at GA 23 to 26 weeks (ibuprofen, 3 [8%] vs nonintervention, 1 [2%], P = .34). In addition, the ductal closure rates before hospital discharge (ibuprofen, 62 [89%] vs nonintervention, 59 [82%], P = .27) and device closure (ibuprofen, 2 [3%] vs nonintervention, 4 [6%], P = .40) were not significantly different between the 2 groups. The nonintervention approach was noninferior to ibuprofen treatment in terms of BPD incidence or death (nonintervention, 44%; ibuprofen, 50%; 95% CI, -0.11 to 0.22; noninferiority margin -0.2; P = .51). One infant in the ibuprofen arm received oral ibuprofen backup rescue treatment owing to cardiopulmonary compromise refractory to conservative management, and another infant in the ibuprofen group received surgical ligation; none of the infants in the placebo group received backup treatment.

CONCLUSIONS AND RELEVANCE

Nonintervention showed noninferiority compared with ibuprofen treatment in closing of hemodynamically significant PDA and reduction of BPD or death. The noninferiority of nonintervention over ibuprofen might be attributable to the low efficacy of oral ibuprofen for closing PDA, especially in infants born at 23 to 26 weeks' gestation.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02128191.

Neonatal Intensive Care Unit-Level Patent Ductus Arteriosus Treatment Rates and Outcomes in Infants Born Extremely Preterm

OBJECTIVES

To assess associations between neonatal intensive care unit (NICU)-level patent ductus arteriosus (PDA) treatment rates (pharmacologic or surgical) and neonatal outcomes.

STUDY DESIGN

This cohort study included infants born at 24-28 weeks of gestation and birth weight <1500 g in 2007-2015 in NICUs caring for ≥100 eligible infants in 6 countries. The ratio of observed/expected (O/E) PDA treatment rates was derived for each NICU by estimating the expected rate using a logistic regression model adjusted for potential confounders and network. The primary composite outcome was death or severe neurologic injury (grades III-IV intraventricular hemorrhage or periventricular leukomalacia). The associations between the NICU-level O/E PDA treatment ratio and neonatal outcomes were assessed using linear regression analyses including a quadratic effect (a square term) of the O/E PDA treatment ratio.

RESULTS

From 139 NICUs, 39 096 infants were included. The overall PDA treatment rate was 45% in the cohort (13%-77% by NICU) and the O/E PDA treatment ratio ranged from 0.30 to 2.14. The relationship between the O/E PDA treatment ratio and primary composite outcome was U-shaped, with the nadir at a ratio of 1.13 and a significant quadratic effect (P<.001). U-shaped relationships were also identified with death, severe neurologic injury, and necrotizing enterocolitis.

CONCLUSIONS

Both low and high PDA treatment rates were associated with death or severe neurologic injury, whereas a moderate approach was associated with optimal outcomes.

International Perspectives: Implementation of the Korean Neonatal Network

Although there has been a marked increase in the number of NICUs in Korea, the gap in quality improvement has remained a national focus. The Korean Neonatal Network (KNN) was established in 2013 by the Korean Society of Neonatology with support from the Korea Centers for Disease Control and Prevention, with the aim of improving neonatal outcomes by offering data-driven interactive tools to all participating NICUs. Approximately 2,000 very-low-birthweight (VLBW) infants from 70 participating hospital NICUs are registered annually in the KNN, with a total of over 12,000 to date. In addition to providing a national registry of VLBW infants, this unique system also leads to an infrastructure for quality improvement in neonatal care, which in turn has an effect on the development of evidence-based neonatal medicine in Korea. Furthermore, it is encouraging that the KNN plans to develop tools to facilitate multicenter clinical trials and to join the global international network for international collaboration.

Changes in Serum Creatinine Levels and Natural Evolution of Acute Kidney Injury with Conservative Management of Hemodynamically Significant Patent Ductus Arteriosus in Extremely Preterm Infants at 23-26 Weeks of Gestation

Changes in kidney function in extremely preterm infants (EPT) with conservatively managed hemodynamically significant (HS) patent ductus arteriosus (PDA) are not known well. We aimed to present the postnatal course in serum creatinine levels (sCr), prevalence of acute kidney injury (AKI), then relevance between AKI and adverse outcomes in EPT with conservatively managed HS PDA. By review of medical records, we analyzed the postnatal course of sCr and prevalence of stage 3 AKI defined by the modified Kidney Disease Improving Global Outcome (KDIGO) in EPT at gestational age of 23 to 26 weeks with conservatively treated HS PDA. We investigated if the presence and/or prolonged duration of stage 3 AKI elevated the risk of adverse outcomes. The results showed that, neither factor was associated with adverse outcomes. While the average PDA closure date was at postnatal day (P) 41 and 53, sCr peaked at P 10 and 14 and the cumulative prevalence of stage 3 AKI was 57% and 72% in the EPT of 25–26 and 23–24 weeks’ gestation, respectively. The high prevalence of stage 3 AKI without adverse outcomes in EPT with conservatively managed HS PDA suggests that it might reflect renal immaturity rather than pathologic conditions.

Nutritional therapies in the neonatal intensive care unit and post-natal growth outcomes of preterm very low birthweight Asian infants

AIM

A collaborative study was conducted between two Southeast Asian university hospitals to compare the nutritional intervention and growth outcomes and evaluate the extent of post-natal growth faltering (PNGF) among very low birthweight (VLBW) infants.

METHODS

Data of all infants admitted during the 2011-2012 period to the two hospitals at Singapore (SG) and Malaysia (MY) were pooled and analysed.

RESULTS

Of the 236 infants, SG infants received lower total protein and energy intake than MY infants (2.69 vs. 3.54 g/kg/day and 92.4 vs. 128.9 kcal/kg/day respectively; P < 0.001) in enteral feeds, with Singaporean infants predominantly fed fortified breast milk than Malaysian infants (45/48 vs. 10/41; P < 0.01). The mean weight z-score from birth to 36 weeks corrected age was significantly different (SG,-2.2 (0.9) vs. MY, -1.4 (0.7); P = 0.001). More SG than MY extremely low birthweight (ELBW) infants had severe PNGF >-2 SDS (55 vs. 16%; P = 0.001). The greater use of a diuretic in SG to treat haemodynamically significant patent ductus arteriosus (hsPDA) may have contributed to the higher PNGF rate. Mean growth velocity of at least 15 g/kg/day was attained by VLBW infants only from Day 14 and by ELBW infants only from Day 28 post-natally. Overall, severe PNGF rates (z-score change >-2 SDS at 36 weeks' corrected age) were 28.8 and 36.5% for VLBW and ELBW infants, respectively.

CONCLUSIONS

Being very preterm, ELBW with hsPDA and receiving insufficient protein and energy were risk factors for severe PNGF. Increasing protein and energy content, augmenting fortification of breast milk and concentrating feed volumes, especially if there is an hsPDA, may curb severe PNGF among these infants.

An Observational, Prospective, Multicenter, Registry-Based Cohort Study Comparing Conservative and Medical Management for Patent Ductus Arteriosus

No consensus has been reached on which patent ductus arteriosus (PDAs) in preterm infants require treatment and if so, how, and when they should be treated. A prospective, multicenter, cohort study was conducted to compare the effects of conservative approaches and medical treatment options on ductal closure at discharge, surgical ligation, prematurity-related morbidities, and mortality. Infants between 24^0/7 and 28^6/7 weeks of gestation from 24 neonatal intensive care units were enrolled. Data on PDA management and patients' clinical characteristics were recorded prospectively. Patients with moderate-to-large PDA were compared. Among the 1,193 enrolled infants (26.7 ± 1.4 weeks and 926 ± 243 g), 649 (54%) had no or small PDA, whereas 544 (46%) had moderate-to-large PDA. One hundred thirty (24%) infants with moderate-to-large PDA were managed conservatively, in contrast to 414 (76%) who received medical treatment. Eighty (62%) of 130 infants who were managed conservatively did not receive any rescue treatment and the PDA closure rate was 53% at discharge. There were no differences in the rates of late-onset sepsis, necrotizing enterocolitis (NEC), retinopathy of prematurity, intraventricular hemorrhage (≥Grade 3), surgical ligation, and presence of PDA at discharge between conservatively-managed and medically-treated infants (p > 0.05). Multivariate analysis including perinatal factors showed that medical treatment was associated with increased risk for mortality (OR 1.68, 95% Cl 1.01-2.80, p = 0.046), but decreased risk for BPD or death (BPD/death) (OR 0.59, 95%Cl 0.37-0.92, p = 0.022). The preferred treatment options were ibuprofen (intravenous 36%, oral 31%), and paracetamol (intravenous 26%, oral 7%). Infants who were treated with oral paracetamol had higher rates of NEC and mortality in comparison to other treatment options. Infants treated before postnatal day 7 had higher rates of mortality and BPD/death than infants who were conservatively managed or treated beyond day 7 (p = 0.009 and 0.007, respectively). In preterm infants born at <29 weeks of gestation with moderate-to-large PDA, medical treatment did not show any reduction in the rates of open PDA at discharge, surgical or prematurity-related secondary outcomes. In addition to the high incidence of spontaneous closure of PDA in the first week of life, early treatment (<7 days) was associated with higher rates of mortality and BPD/death.