Echocardiographic Diagnosis and Hemodynamic Evaluation of Patent Ductus Arteriosus in Extremely Low Gestational Age Newborn (ELGAN) Infants

Initiation of enteral feeding as per current protocol (at 24 h) versus as per clinical status (from 6 h onwards) in neonates born with antenatal reversed end diastolic flow (REDF) in the umbilical artery Doppler: a pilot randomized controlled trial

OBJECTIVE

To compare the effects of initiating feeds at 24 h versus at 6 h in neonates with reversed end-diastolic flow (REDF) and determine the incidence of feed intolerance (FI) and necrotizing enterocolitis (NEC).

DESIGN

Pilot randomized controlled trial.

METHODS

Neonates with REDF (n = 52) were randomized to start feeds at 6 h (n = 26) or 24 h (n = 26) to assess FI, NEC, time to full feeds, sepsis, mortality, weight and gestation at discharge, and hospital stay.

RESULTS

FI was observed in 14 (54%) neonates in 6 h group and 17 (65%) in 24 h group, with comparable NEC rates. Neonates in the 6 h group achieved full feeds faster (8 vs. 11 days) and had shorter hospital stay (17 vs. 32 days). Death and sepsis rates were similar.

CONCLUSIONS

Feed initiation at 6 h in REDF neonates did not increase the risk of FI or NEC.

TRIAL REGISTRATION

Clinical trial registry of India (CTRI/2023/02/050025); 23/02/2023.

Serum Biomarkers in Patent Ductus Arteriosus in Preterm Infants: A Narrative Review

Background: Patent ductus arteriosus (PDA) in preterm infants presents a significant challenge in neonatal care, marked by ongoing debates about its definition, diagnosis, treatment options, and effects on patient outcomes. Plasma biomarkers assess mediators involved in PDA closure and hemodynamic responses, assisting in identifying newborns at higher risk of developing potentially serious neonatal conditions. The purpose of this review was to investigate the relationship between PDA and various plasma biomarkers used to evaluate and diagnose ductal patency during perinatal life, as outlined in the relevant literature. Methods: We conducted an electronic search of the National Library of Medicine (MEDLINE)/PubMed and Web of Science for relevant studies published up to December 2024, including prospective, retrospective, cohort, and cross-sectional studies, as well as reviews and meta-analyses. The keywords used in the search included "preterm infant", "persistent ductus arteriosus", "patent ductus arteriosus", "PDA", "neonatal biomarkers", "cardiac biomarkers", and "vasoactive biomarkers". Results: Out of the 813 identified articles, 85 were included in our review of cardiac biomarkers: Natriuretic peptides (NPs), Cardiac troponin T (cTnT), vasoactive biomarkers (Mid-regional pro-adrenomedullin (MR-proADM), Endothelin-1 (ET-1), Copeptin, and Isoprostanes (IPs)), and inflammatory biomarkers (Interleukin-6 (IL-6), IL-8, IL-10, Growth Differentiation Factor 15 (GDF-15), Monocyte Chemoattractant Protein-1 (MCP-1/CCL2), Macrophage Inflammatory Protein-1α (MIP-1α/CCL3)) in relation to PDA. Conclusions: Even if research shows a strong correlation between specific biomarkers and echocardiographic parameters in patients with PDA, clinical judgment must take these evaluations into account, particularly when determining whether to treat a PDA. Future research should focus on investigating new biomarkers associated with the underlying mechanisms of perinatal ductus arteriosus dynamics in preterm infants.

Oral ibuprofen versus placebo in closure of patent ductus arteriosus in preterm neonates, a randomized control trial

BACKGROUND

A consensus on treatment of patent ductus arteriosus (PDA) in preterm neonates remains elusive. Conservative management has recently gained popularity due to medical treatment lacking the evidence of benefit in terms of mortality and morbidity.

OBJECTIVE

This study compares the efficacy of the standard dose of oral Ibuprofen versus placebo in the closure of PDA in preterm neonates ≤34 weeks gestation.

METHODS

Eighty enrolled preterm neonates with a hemodynamically significant PDA (hsPDA) were randomized to either receive an early 3-day course oral ibuprofen or placebo (1:1). The open-label option and an extended oral ibuprofen therapy were offered if there were concerns over patient's clinical condition being attributed to PDA and only if showing evidence of systemic and/or pulmonary hyperperfusion.

RESULTS

No significant difference in PDA closure between both groups (62.5% vs 65% in Ibuprofen & placebo group respectively, p = .816). No significant difference was observed between groups in mortality (p = 1), Bronchopulmonary dysplasia (BPD) (p = 1), or necrotizing enterocolitis (NEC) (0.5). Placebo group required a longer duration of inotropic support (median of 10 vs 7.5 days in Ibuprofen group, p = .013) and were prescribed more diuretic therapy (27 vs 18 in Ibuprofen group, p = .043).

CONCLUSION

The standard dose of oral ibuprofen was comparable to placebo in early treatment of hsPDA in preterm neonates less than 34 weeks in terms of effect on ductal closure after one course of treatment, incidence of mortality, and morbidities like NEC, and BPD. Failure of ductal closure itself was associated in both groups with increased mortality, failure to reach full feeds, and more use of vasopressors and inotropes.

Omic-signature of bronchopulmonary dysplasia associated pulmonary hypertension in <1500g-birth-weight-infants with hemodynamically significant intracardiac shunt

BACKGROUND

PDA and ASD are common intracardiac shunts noted in prematurely born infants. While there is evidence of persistent PDA and ASD associated with a higher risk for developing bronchopulmonary dysplasia (ICS-BPD) and pulmonary hypertension (ICS-BPD-PH), the underlying pathogenesis is poorly understood and hence challenging to identify at-risk infants. Our study goal was to evaluate transcriptomic expression and associated pathways in tracheal aspirates (TAs) of low-birth-weight infants with hemodynamically significant cardiac shunt (ICS) that develop bronchopulmonary dysplasia (ICS-BPD) and pulmonary hypertension (ICS-BPD-PH).

METHODS

TAs were collected from preterm infants with ICS and a diagnosis of BPD or BPD-PH from a single center. 36 TA samples including 19 ICS-BPD and 17 ICS-BPD-PH were analyzed. MiRNA expression was determined via PCR arrays, and mRNA expression via RNA seq. Data were analyzed using limma.

RESULTS

11 miRNAs and 10 mRNAs were differentially expressed (adjusted p < 0.05) in ICS-BPD-PH group when compared to ICS-BPD. Ingenuity Pathway Analysis identified associations with cellular growth, proliferation, death, and cell function pathways.

CONCLUSION

TAs from preterm infants show differentially expressed miRNAs and mRNAs in ICS-BPD-PH when compared to ICS-BPD, an in-silico model identified target molecules that could be playing a role in BPD-PH pathogenesis in low-birth-weight infants with ICS.

IMPACT

Pulmonary hypertension associated with severe BPD (BPD-PH) is a distinct disease in preterm infants with severe BPD and the role of intracardiac shunt (ICS) in its development is controversial and often challenging for clinical management. Our pilot study, researching specific endotyping of infants with pulmonary hypertension associated with BPD using multiomics approach has identified molecular markers and potential underlying pathways associated with this condition. These markers could aid in stratifying high risk infants with ICS that are at risk for developing BPD-PH and aid clinical management.

Echocardiographic evaluation of left atrial volume and comparative analysis to left atrial to aortic root ratio in premature neonates and infants with patent ductus arteriosus

PURPOSE

Left atrium to aortic root ratio (LA/Ao) is an echocardiographic marker of hemodynamically significant patent ductus arteriosus (PDA). Since 2-dimensional measurement of the ratio is geometrically limited, left atrial volume (LAV) which has 3-dimensional characteristics was investigated. The aim of this study was to determine a correlation between LA/Ao ratio and LAV as well as holodiastolic flow reversal in preterm neonates with and without a PDA.

METHODS

A retrospective evaluation of neonates with and without PDA was performed. Targeted neonatal echocardiography evaluation of LA/Ao and LAV was measured from parasternal long-axis view and the apical 4 and 2-chamber views, respectively. Univariate and linear regression analysis were performed.

RESULTS

200 patients were included of whom 158 (79.0%) had a PDA shunt. The median gestational age at the time of echo was 27.4 weeks (IQR: 25.7-29.4 weeks). The median LA/Ao ratio was 1.51 (IQR: 1.26-1.83) and median LAV indexed to weight was  .91 mL/kg (IQR: .65-1.18 mL/kg). There was a significant correlation between LA/Ao and LAV indexed to weight in the PDA group (r2 = .080, p = .0003). LA/Ao ratio and LAV indexed to weight differed significantly between those with diastolic flow reversal versus no-flow reversal (LA/Ao, p = .003; LAV, p = .001).

CONCLUSIONS

This study demonstrated a significant correlation between LA/Ao and LAV in preterm infants with PDA, with greater magnitude of discordance for LAV. The power of LAV versus LA/Ao in monitoring hemodynamically significant PDA requires prospective evaluation.

Narrative Review on Echocardiographic Evaluation of Patent Ductus Arteriosus in Preterm Infants

Persistent Patent Ductus Arteriosus (PDA) is prevalent among extremely preterm infants, with its occurrence inversely related to gestational age. A persistent PDA correlates with increased mortality and morbidities such as intraventricular hemorrhage, pulmonary hemorrhage, chronic lung disease, bronchopulmonary dysplasia, and necrotizing enterocolitis as observed clinically. Conversely, numerous randomized controlled trials have failed to demonstrate significant benefits from PDA treatment. One contributing factor to these conflicting findings is that PDA affects each individual differently depending on the cardiovascular decompensation and its hemodynamic impact. PDA management should be based on the hemodynamic significance, rather than just the presence or size of PDA. This comprehensive narrative review paper describes echocardiographic parameters that allow a better understanding of the hemodynamic impact of PDA. A newer modality, like lung ultrasound, is also described here as an adjunct to assess the PDA impact on the lungs from pulmonary overcirculation.

Cerebrovascular Autoregulation in Preterm Infants Using Heart Rate or Blood Pressure: A Pilot Study

BACKGROUND

Cerebrovascular autoregulation (CAR) is often impaired in preterm infants but requires invasive mean arterial blood pressure (MABP) measurements for continuous assessment. We aimed to assess whether using heart rate (HR) results in different CAR assessment compared with using MABP.

METHODS

We compared CAR (moving window correlation-coefficient with cerebral oxygenation saturation (rcSO2)), and percentage of time with impaired CAR (%timeCARi) calculated by either HR (TOHRx, tissue oxygenation heart rate reactivity index) or MABP (COx, cerebral oximetry index) during the first 72 h after birth, and its association with short-term cerebral injury.

RESULTS

We included 32 infants, median gestational age of 25 + 5/7 weeks (interquartile range 24 + 6/7-27 + 5/7). COx and TOHRx correlation coefficients (cc) were significantly different in the first two days after birth (individual means ranging from 0.02 to 0.07 and -0.05 to 0.01). %TimeCARi using MABP (cc cut-off 0.3), was higher on day 1 (26.1% vs. 17.7%) and day 3 (23.4% vs. 16.9%) compared with HR (cc cutoff -0.3). During 65.7-69.6% of the time, both methods indicated impaired CAR simultaneously. The aforementioned calculations were not associated with early cerebral injury.

CONCLUSIONS

In conclusion, HR and MABP do not seem interchangeable when assessing CAR in preterm infants.

Doppler Ultrasonographic Assessment of Abdominal Aortic Flow to Evaluate the Hemodynamic Relevance of Left-to-Right Shunting Patent Ductus Arteriosus in Dogs

In this multicenter, prospective, observational study, abdominal aortic flow was examined with pulsed-wave Doppler ultrasound in dogs with a left-to-right shunting patent ductus arteriosus (PDA) and in apparently healthy dogs. Forty-eight dogs with a PDA and 35 controls were included. In the dogs with a PDA, 37/48 had hemodynamically significant PDAs (hsPDAs) while 11/48 had non-hsPDAs, based on the presence or absence of echocardiographic signs of left-sided volume overload, respectively. In 12 dogs (4/35 control dogs, 7/37 dogs with an hsPDA and 1/11 dogs with a non-hsPDA), the diastole was too short to visualize the end-diastolic flow. Antegrade end-diastolic flow was observed in 30/35 controls and 6/11 dogs with a non-hsPDA. Absent end-diastolic flow was observed in 1/35 control dogs and 3/11 dogs with a non-hsPDA. Retrograde end-diastolic flow was observed in 30/37 dogs with an hsPDA and 1/11 dogs with a non-hsPDA. Twenty-one dogs (15 with an hsPDA and 6 with a non-hsPDA) were reassessed after PDA closure, and, in 19/21, end-diastolic flow was visualized: 17/19 showed an antegrade flow, 1/19 an absent flow and 1/19 a retrograde flow. Sensitivity and specificity of retrograde end-diastolic flow for detection of hsPDAs were 100% and 90%, respectively. In conclusion, ultrasonographic assessment of abdominal aortic flow was feasible in dogs with PDA. However, end-diastolic flow was not always visualized. The presence of a retrograde end-diastolic flow was an accurate finding for discriminating hsPDAs and non-hsPDAs.

Echocardiography in the neonatal unit: current status and future prospects

INTRODUCTION

Traditionally echocardiography was used by pediatric cardiologists to diagnose congenital heart defects in neonates. Formalized neonatal hemodynamic fellowships have been established where neonatologists acquire advanced echocardiographic skills to gain anatomical, physiological, and hemodynamic information in real time and utilize this information in making a timely and accurate physiology-based clinical decision.

AREA COVERED

Differences between a comprehensive formal structural echocardiography, neonatologist performed targeted echocardiography and limited assessment on point-of-care-ultrasonography for specific indications have been covered. This article is focused at providing a comprehensive review of the status of echocardiography in the neonatal units, recent advancements and its future prospects in the neonatal intensive care units.

EXPERT OPINION

Comprehensive guidelines providing the scope of practice, a framework for training, and robust clinical governance process for the neonatologist performed targeted echocardiography have been established. In the last decade, echocardiography has emerged as essential vital bedside diagnostic tool in providing high-quality care to the sick infants in the neonatal units, and it has proved to improve the outcomes in neonates. It is now being considered as a modern hemodynamic monitoring tool. Advances in technology, machine learning, and application of artificial intelligence in applications of echocardiography seem promising adjunct tools for rapid assessment in emergency situations.

Personalized Evidence-Based Management of Patent Ductus Arteriosus in Preterm Infants

There is no universal consensus on management of patent ductus arteriosus (PDA) in preterm infants and it varies significantly worldwide, even among the clinicians within units. The decision to treat requires a thorough understanding of the clinical status of the patient, clinical evaluation of PDA, echocardiographic diagnosis, and hemodynamic impact of ductal shunt on the pulmonary and systemic circulation. In this article, updated evidence on the efficacy and adverse effects of pharmacological treatment options and expectant management are presented, while highlighting the long-term benefits of PDA treatment remains equivocal and controversial. The authors propose a schematic targeted PDA treatment approach based on gestational and chronological age for practical clinical use, and they emphasize important future directions including advancement in PDA device closure techniques, diagnostic echo-parameters, hemodynamic evaluation to assess the impact on other organs, and understanding the long-term outcomes.

The Transcatheter Closure of Patent Ductus Arteriosus in Extremely Low-Birth-Weight Infants: Technique and Results

Persistent patent ductus arteriosus is a very common condition in preterm infants. Although there is no management agreed by consensus, despite numerous randomized controlled trials, hemodynamically significant patent ductus arteriosus increases morbidity and mortality in these vulnerable patients. Medical treatment is usually offered as first-line therapy, although it carries a limited success rate and potential severe adverse events. In recent years, transcatheter patent ductus arteriosus closure has fast developed and become widely accepted as a safe and efficient alternative to surgical ductal ligation in extremely low birth weight infants >700 g, using most often the dedicated Amplatzer Piccolo Occluder device. This article aims to provide an appraisal of the patients' selection process, and a step-by-step description of the procedure as well as a comprehensive review of its outcomes.

Lung ultrasound score predicts patent ductus arteriosus ligation among neonates ≤25 weeks

BACKGROUND

This prospective study aimed to investigate whether lung ultrasound score (LUSs) can predict the patent ductus arteriosus (PDA) ligation.

METHODS

Preterm infants ≤25 weeks of gestational age (GA) were enrolled. A lung ultrasound was performed on the 14th day of life. Each lung zone was given a score between 0 and 4. A receiver-operating characteristic (ROC) curve was constructed to evaluate the ability of the LUSs for predicting ligation.

RESULTS

A total of 81 infants were eligible with a median GA and birth weight (BW) of 25 weeks (24.1-25.2) and 710 g (645-770), respectively. The median time from birth to ligation was 35 days (32-51). Those who underwent ligation had a longer time of mechanical ventilation (34 [26-39] vs. 19 [12-30], p < 0.001), shorter time of noninvasive respiratory support (39 [32-51] vs. 50 [41.5-57], p < 0.01), higher incidence of the bronchopulmonary dysplasia (BPD) (p < 0.01), and severe BPD (p < 0.001). The LUSs had an area under the ROC of 0.96 (95% confidence interval: 0.93-0.99) for the prediction of ligation. A LUSs cutoff of 36 has a sensitivity and specificity of 96% and 86% and positive and negative predictive values of 82% and 98%, respectively.

CONCLUSIONS

LUSs at an early stage of life can predict PDA ligation in extremely preterm infants. It would be helpful to reduce morbidity by reducing the duration and magnitude of respiratory support.

Transport and Anaesthesia Consideration for Transcatheter Patent Ductus Arteriosus Closure in Premature Infants

Transcatheter device closure of patent ductus arteriosus (PDA) in preterm infants has been proven to be a feasible and safe technique with promising results when compared to surgical ligation. However, managing transport and anaesthesia in extremely premature infants with haemodynamically significant PDA and limited reserves presents unique challenges. This review article focuses on the key considerations throughout the clinical pathway for the PDA device closure, including referral hospital consultation, patient selection, intra- and inter-hospital transport, and anaesthesia management. The key elements encompass comprehensive patient assessment, meticulous airway management, optimised ventilation strategies, precise thermoregulation, patient-tailored sedation protocols, vigilant haemodynamic monitoring, and safe transport measures throughout the pre-operative, intra-operative, and post-operative phases. A multidisciplinary approach enhances the chances of procedure success, improves patient outcomes, and minimises the risk of complications.

The Predictive Value of Lung Ultrasound Score on Hemodynamically Significant Patent Ductus Arteriosus among Neonates ≤25 Weeks

Lung ultrasound (LU) is increasingly used to diagnose and monitor neonatal pulmonary disorders; however, its role in hemodynamically significant patent ductus arteriosus (hsPDA) has not been elucidated. This prospective study investigated the predictive value of the LU score (LUS) for hsPDA in preterm infants with gestational age (GA) ≤ 25 weeks. Preterm infants with GA ≤ 25 weeks were enrolled in this study. LU was conducted on the fourth day of life (DOL). Six lung regions in every lung were scanned, with each region rated as 0-4 points. The performance of the LUS in predicting hsPDA among infants aged ≤25 weeks was analyzed by plotting the receiver operating characteristic (ROC) curve. A total of 81 infants were included in this study. GA, birth weight (BW), gender, Apgar score, delivery mode, antenatal steroids, meconium-stained amniotic fluid, premature rapture of membrane, and early-onset sepsis were not significantly different, but infants in the hsPDA group had increased LUS (38.2 ± 2.8 vs. 30.3 ± 4.3, p < 0.001) compared with non-hsPDA group. The area under the ROC curve (AUC) value of the LUS on the fourth DOL was 0.94 (95% CI: 0.93-0.99) in predicting hsPDA. The LUS threshold at 33 achieved 89% sensitivity and 83% specificity, with the positive and negative predictive values (PPV and NPV) being 87 and 86%, respectively. The LUS can predict hsPDA in extremely preterm infants at an early stage.

Use of Cardio-Pulmonary Ultrasound in the Neonatal Intensive Care Unit

Cardiopulmonary ultrasound (CPUS), the combination of lung ultrasound (LUS) and targeted neonatal echocardiography (TnECHO)AA, may offer a more appropriate approach to the challenging neonatal cardiovascular and respiratory disorders. This paper reviews the possible use of CPUS in the neonatal intensive care unit (NICU).

Predictive value of a nomogram model for adverse outcomes in very low birth weight infants with patent ductus arteriosus: A prospective study

Objective

To establish a nomogram model incorporating markers of echocardiography and N-terminal pro brain natriuretic peptide (NT-proBNP) for predicting adverse outcomes of patent ductus arteriosus (PDAao) in very low birth weight infants and to evaluate the predictive values of the model.

Methods

A prospective study was conducted for very low birth weight infants who were admitted from May 2019 to September 2020. An echocardiogram and blood NT-proBNP test were carried out in the first 48 h after birth, and the arterial duct remained open in all patients. Other data collected included clinical symptoms and infant characteristics. A nomogram model was established to predict the risk of PDAao (including severe BPD, IVH, NEC or death). Internal verifications were performed for the nomogram, and the discrimination and calibration of the model were evaluated by the C-index and calibration curve.

Results

Eighty-two infants were enrolled and divided into an adverse outcome (AO) group and normal outcome (NO) group with 41 patients in each group. PDA diameter, PDA maximum flow velocity, left atrium diameter/aortic diameter (LA/AO) ratio and NT-proBNP level were independent risk factors for PDAao and were included in the nomogram model. The model presented good discrimination with a C-index of 0.917 (95% CI 0.859-0.975). The calibration curves in showed high consistency and indicated good Correspondence: between the event incidence predicted by the nomogram model and the true incidence of PDAao.

Conclusion

The nomogram model incorporating the PDA diameter, PDA maximum flow velocity, LA/AO ratio and NT-proBNP level in the first 48 h could early predict the later occurrence of PDAao in very low birth weight infants.

Impact of Medical Treatment of Hemodynamically Significant Patent Ductus Arteriosus on Cerebral and Renal Tissue Oxygenation Measured by Near-Infrared Spectroscopy in Very Low-Birth-Weight Infants

Background and objective: Hemodynamically significant patent ductus arteriosus (hsPDA) can cause ductal steal and contribute to poor outcomes in preterm infants. Near-infrared spectroscopy (NIRS) allows us to continuously evaluate regional tissue oxygenation (rSpO2) and perfusion changes in underlying organs. The aim of this study was to evaluate the effect of medical treatment for hsPDA on cerebral and renal rSpO2 in infants less than 32 weeks of gestational age, and older than 72 h of life. Materials and methods: Infants with a gestational age of <32 weeks with hsPDA were prospectively studied before and during medical treatment. Two-site (cerebral and renal) rSpO2 monitoring by NIRS was performed 1 h before treatment (T0) and 24 h (T1), 24−48 h (T2), 48−72 h (T3) after the infusion of the first drug dose. Results: A total of 21 infants were studied. The mean day of life at treatment initiation was 8.2 (SD, 2.75). The DA diameter, LA/Ao ratio, and resistive index in the anterior cerebral artery (RI ACA) were significantly lower after treatment (p < 0.05). There were no significant differences in cerebral rSpO2, cerebral fractional tissue oxygen extraction (FTOE), and SpO2 comparing different time points. A significantly higher renal SpO2 value was recorded at T2 as compared with T0 (75.0%, SD 4.9%, vs. 69.4%, SD 7.6%; p < 0.013), while for renal FTOE, a tendency to lower values at T2 was observed (0.18, SD 0.05, vs. 0.24, SD 0.09; p = 0.068). Conclusions: Late (later than 7 days postpartum) hsPDA medical treatment with paracetamol or ibuprofen completely closed the duct only in a small proportion of preterm infants, despite a statistically significant reduction in the DA diameter, LA/Ao ratio, and RI ACA. Continuous renal, not cerebral, NIRS measurements can help to anticipate the efficacy of medical treatment of hsPDA in preterm infants. Large-scale prospective studies are needed to ascertain that renal and cerebral NIRS can be used as a reliable tool for evaluating the effectiveness of medical treatment for hsPDA.

The high-risk factors of different severities of bronchopulmonary dysplasia (BPD) based on the national institute of child health and human development (NICHD) diagnosis criteria in 2018

Objective

To investigate the clinical characteristics of preterm infants with different severities of bronchopulmonary dysplasia (BPD) and disclose the high-risk factors of exacerbating BPD.

Methods

Collection of clinical data of 91 preterm infants admitted to the NICU and diagnosed with BPD, categorized in groups according to the disease severity: 41 mild cases,, 24 moderate cases, and 26 severe cases. Comparison and analysis of perinatal risk factors, treatment, complications and prognosis of the infants with different severity degrees.

Results

The severe group had a higher proportion of infants with congenital heart disease (CHD) higher than the moderate group (P < 0.05), and a higher ratio of pneumonia and mechanical ventilation (MV) ≥ seven days than the mild group (P < 0.05). The severe group also presented higher reintubation incidence than both the mild and moderate groups (P < 0.05). The groups presented different (P < 0.05) incidence rates of hemodynamically significant patent ductus arteriosus (hsPDA) . Ridit analysis suggested that the premature infants (PIs) with hsPDA, multiple microbial pulmonary infections, or Klebsiella pneumoniae pneumonia had more severe illness.

Conclusion

CHD, hsPDA, MV ≥ seven days, reintubation, pneumonia, especially multiple microbial pulmonary infections, and Klebsiella pneumoniae pneumonia are correlated with the severity of BPD and can be used as BPD progression predictor.

Case Report: Intact Survival of a Marginally Viable Male Infant Born Weighing 268 Grams at 24 Weeks Gestation

We report the case of a preterm small for gestational age male infant born at 24 weeks of gestation with a birth weight of 268 g who was discharged from our hospital without the requirement for home oxygen therapy or tube feeding. He did not experience severe intraventricular hemorrhage, periventricular leukomalacia, hearing disability, or any other serious complications. At that time (February 2019), according to the University of Iowa's Tiniest Babies Registry, he was the tiniest male infant in the world to survive without any serious complications other than severe retinopathy of prematurity that required laser therapy. Although the survival rate of infants with extremely low birth weight is improving worldwide, a high mortality rate and incidence of severe complications remain common for infants weighing <300 g at birth, particularly in male infants. In recent years, there have been frequent discussions regarding the ethical and social issues involved in treating extremely preterm infants weighing <400 g. Despite the challenges, reports of such infants surviving are increasing. Neonatal medicine has already achieved great success in treating infants weighing 400 g or more at birth. However, lack of evidence and experience may make physicians reluctant to treat infants weighing less than this. The present case demonstrates that intact survival of a marginally viable male infant with a birth weight of <300 g is possible with minimal handling and family involvement beginning shortly after birth. Our detailed description of the clinical course of this case should provide invaluable information to physicians around the world who treat such infants. This report will aid in the progress of neonatal medicine and help to address many of the social and ethical issues surrounding their care.

Objective Assessment of Physiologic Alterations Associated With Hemodynamically Significant Patent Ductus Arteriosus in Extremely Premature Neonates

Delay in closure of ductus arteriosus in postnatal life may lead to serious consequences and complications in an extremely premature neonate secondary to hemodynamic alterations in regional blood flow pattern in various organs. Despite the widespread recognition amongst neonatologists to identify a hemodynamically significant patent ductus arteriosus (hsPDA) early in the postnatal course, there is lack of consensus in its definition and thus the threshold to initiate treatment. Echocardiographic assessment of PDA shunt size and volume combined with neonatologists' impression of clinical significance is most frequently used to determine the need for treatment of PDA. Common clinical signs of hsPDA utilized as surrogate for decreased tissue perfusion may lag behind early echocardiographic signs. Although echocardiogram allows direct assessment of PDA shunt and hemodynamic alterations in the heart, it is limited by dependence on pediatric cardiologist availability, interobserver variation and isolated time point assessment. Electrical cardiometry (EC) is a non-invasive continuous real time measurement of cardiac output by applying changes in thoracic electrical impedance. EC has been validated in preterm newborns by concomitant transthoracic echocardiogram assessments and may be beneficial in studying changes in cardiac output in premature newborns with hsPDA. Alterations in perfusion index derived from continuous pulse oximetry monitoring has been used to study changes in cardiac performance and tissue perfusion in infants with PDA. Near infrared spectroscopy (NIRS) has been used to objectively and continuously assess variations in renal, mesenteric, and cerebral oxygen saturation and thus perfusion changes due to diastolic vascular steal from hsPDA in preterm neonates. Doppler ultrasound studies measuring resistive indices in cerebral circulation indicate disturbance in cerebral perfusion secondary to ductal steal. With recent trends of change in practice toward less intervention in care of preterm newborn, treatment strategy needs to be targeted for select preterm population most vulnerable to adverse hemodynamic effects of PDA. Integration of these novel ways of hemodynamic and tissue perfusion assessment in routine clinical care may help mitigate the challenges in defining and targeting treatment of hsPDA thereby improving outcomes in extremely premature neonates.

SIMPLE: A Novel Scoring System for Predicting Hemodynamically Significant Patent Ductus Arteriosus Without Echocardiographic Evaluation in Extremely Low Birth Weight Infants

Aim: To develop a novel clinical scoring system for predicting hemodynamically significant patent ductus arteriosus (hsPDA) in extremely low birth weight (ELBW) infants. Methods: A prospective observational study was conducted among ELBW infants born in the study center during a 6-month period. Fourteen items were selected on a literature review basis and weighed by severity on an arbitrary 1-4 scale, the sum of which represented the Scoring preterm Infants for PDA cLinically without Echocardiographic evaluation (SIMPLE) score. The SIMPLE scores were compared at several time points during the first 3 days of life between two groups of patients: those with an hsPDA at echocardiography and those without. Results: A total of 48 ELBW infants were enrolled, of which 30 infants developed hsPDA. The SIMPLE scores of the infants with hsPDA were significantly greater than those of the infants who did not develop hsPDA. Cut-off SIMPLE scores that were significantly associated with detection of symptomatic hsPDA at each evaluation time point were identified. Conclusions: SIMPLE is the first scoring system that depends on the risk factors and clinical findings of ELBW infants for early prediction of hsPDA. It is simple, objective and easy to perform, and it does not require any additional tests and/or echocardiographic evaluation. We suggest that SIMPLE can be used as a screening tool for determining the need for echocardiographic evaluation in ELBW infants in order to minimize the number of unnecessary pediatric cardiology consultations.

Size of Patent Ductus Arteriosus and Echocardiographic Markers of Shunt Volume in Preterm Infants Based on Postnatal Age

Objective: This study was conducted in order to compare the strength of correlation between echocardiographic markers of shunt volume and patent ductus arteriosus (PDA) diameter based on postnatal age. Methods: This retrospective study focused on preterm infants (aged <32 weeks of gestation) admitted to the Neonatal Intensive Care Unit of Korea University Ansan Hospital, between April 2014 and December 2017, who studied serial targeted neonatal echocardiography (TNE) for PDA during hospitalization. The association between echocardiographic characteristics and duct size was divided into the following days: within 3 days (very early, VE), 4-7 days after birth (early, E), and after 8 days of birth (late, L). Results: We found 113 assessments conducted on 57 infants in the VE period, 92 assessments on 40 infants in the E period, and 342 assessments on 37 infants in the L period. Median gestational age and birth weight were 28⁺² weeks of gestation and 1,115 g, respectively. In the univariate regression analysis, we found a statistically significant correlation between PDA diameter and all TNE markers in the E and L days, but not in the VE period. Only ductal velocity [coefficient of determination (R ²) = 0.224], antegrade left pulmonary artery diastolic flow velocity (R ² = 0.165), left ventricular output (LVO)/superior vena cava (SVC) flow ratio (R ² = 0.048), and E/A wave ratio (R ² = 0.092) showed weak correlations with PDA diameter in the VE period. The slopes of the regressions showed significant changes based on postnatal age in the maximum ductal velocity, left atrium/aorta ratio, LVO/SVC flow ratio, and LVO. Conclusions: It is difficult to predict the echocardiographic markers of shunt volume based on the PDA diameter in preterm infants younger than 4 days. A better understanding of the changes in the hemodynamic consequences of PDA based on postnatal age is needed when considering treatment.

A Matched Case Control Study of Surgically and Non-surgically Treated Patent Ductus Arteriosus in Extremely Pre-term Infants

Introduction: There are still uncertainties about the timing and indication for surgical ligation of patent ductus arteriosus (PDA) in pre-term infants, where lower gestational age (GA) usually is predictive for surgical treatment. Objective: Our aim was to assess differences in clinical characteristics and outcomes between surgically treated and matched non-surgically treated PDA in extremely pre-term infants. Methods: All extremely pre-term infants born 2010-2016 with surgically treated PDA (Ligated group; n = 44) were compared to non-surgically treated infants (Control group; n = 44) matched for gestational age (+/-1 week) and time of birth (+/-1 month). Perinatal parameters, echocardiographic variables, details of pharmacological PDA treatment, morbidity, and mortality were assessed. Result: Mean GA and birthweight were similar between the Ligated group (24⁺⁵ ± 1⁺³ weeks and 668 ± 170 g) and the Control group (24⁺⁵ ± 1⁺³ weeks and 704 ± 166 g; p = 1.000 and p = 0.319, respectively). Infants in the Ligated group had larger ductal diameters prior to pharmacological treatment, and lack of diameter decrease and PDA closure after treatment (p = 0.022, p = 0.043 and 0.006, respectively). Transfusions, post-natal steroids and invasive respiratory support were more common in the Ligated group. Except for a higher incidence of severe bronchopulmonary dysplasia (BPD) in the Ligated group there were no other differences in outcomes or mortality between the groups. Conclusion: Early large ductal diameter and reduced responsiveness to pharmacological treatment predicted the need for future surgical ligation in this matched cohort study of extremely pre-term infants where the effect of GA and differences in treatment strategies were excluded. Besides an increased incidence of severe BPD in the Ligated group, no other differences in morbidity or mortality were detected.