Persistent pulmonary hypertension of the newborn

Progress in the application of echocardiography in neonatal pulmonary hypertension

Purpose: This review aims to overview the use of echocardiography in diagnosing neonatal pulmonary hypertension, assessing cardiac function, and understanding the significance and limitations of various parameters in clinical practice.Materials and methods: Advancements in echocardiography for diagnosing and assessing neonatal pulmonary hypertension, evaluating cardiac function, monitoring treatment effectiveness, and predicting prognosis are discussed.Results: Echocardiography is a pivotal tool for diagnosing and managing neonatal pulmonary hypertension. It should be used with other ultrasound parameters to confirm findings and provide comprehensive analysis for improved accuracy.Conclusion: Understanding the value of echocardiography in neonatal pulmonary hypertension diagnosis and management is crucial. Its integration with other imaging modalities enhances diagnostic accuracy and improves patient outcomes.

Two risk assessment models for predicting white matter injury in extremely preterm infants

BACKGROUND

Extremely preterm infants (EPIs) are at high-risk of white matter injury (WMI), leading to long-term neurodevelopmental impairments. We aimed to develop nomograms for WMI.

METHODS

The study included patients from 31 provinces, spanning ten years. 6074 patients before 2018 were randomly divided into a training and internal validation group (7:3). The external validation group comprised 1492 patients from 2019. Predictors were identified using the least absolute shrinkage and selection operator (LASSO) and multivariable logistic regression and nomograms were constructed. Models' performance was evaluated using receiver operating characteristic (ROC), decision curve analysis (DCA) and calibration curves.

RESULTS

The prenatal nomogram included multiple gestation, premature rupture of membranes (PROM), chorioamnionitis, prenatal glucocorticoids, hypertensive disorder complicating pregnancy (HDCP) and Apgar 1 min, with area under the curve (AUC) of 0.805, 0.816 and 0.799 in the training, internal validation and external validation group, respectively. Days of mechanical ventilation (MV), shock, patent ductus arteriosus (PDA) ligation, intraventricular hemorrhage (IVH) grade III-IV, septicemia, hypothermia and necrotizing enterocolitis (NEC) stage II-III were identified as postpartum predictors. The AUCs were 0.791, 0.813 and 0.823 in the three groups, respectively. DCA and calibration curves showed good clinical utility and consistency.

CONCLUSION

The two nomograms provide clinicians with precise and efficient tools for prediction of WMI.

IMPACT

This study is a large-sample multicenter study, spanning 10 years. The two nomograms are convenient for identifying high-risk infants early, allowing for reducing poor prognosis.

[Protective effects of 2-methoxyestradiol against hypoxic pulmonary hypertension in neonatal rats]

OBJECTIVES

To investigate the protective effects of 2-methoxyestradiol (2ME) against hypoxic pulmonary hypertension (HPH) in neonatal rats.

METHODS

Ninety-six Wistar neonatal rats were randomly divided into a normoxia group, a hypoxia group, and a hypoxia + 2ME group, with each group further subdivided into 3-day, 7-day, 14-day, and 21-day subgroups, containing eight rats each. The hypoxia and hypoxia + 2ME groups received daily subcutaneous injections of saline and 2ME (240 μg/kg), respectively, while the normoxia group was raised in a normoxic environment with daily saline injections. Right ventricular systolic pressure (RVSP) was measured using the direct pressure method. Pulmonary vascular morphology was assessed using hematoxylin and eosin staining, with metrics including the percentage of medial thickness of small pulmonary arteries relative to the external diameter (MT%) and the cross-sectional area of the media of small pulmonary arteries relative to the total cross-sectional area (MA%). Immunohistochemistry was used to detect the expression levels of hypoxia-inducible factor-1α (HIF-1α) and proliferating cell nuclear antigen (PCNA) proteins, while real-time quantitative PCR was used to to assess HIF-1α and PCNA mRNA levels.

RESULTS

Compared to the normoxia group, the hypoxia and hypoxia + 2ME groups showed increased RVSP and upregulated HIF-1α and PCNA protein and mRNA expression levels at 3, 7, 14, and 21 days after hypoxia (P<0.05). Furthermore, at 7, 14, and 21 days after hypoxia, the hypoxia group showed increased MT% and MA% (P<0.05). In comparison to the hypoxia group, the hypoxia + 2ME group exhibited reduced RVSP and downregulated HIF-1α and PCNA protein and mRNA expression levels, along with decreased MT% and MA% at 7, 14, and 21 days after hypoxia (P<0.05).

CONCLUSIONS

2ME may protect against HPH in neonatal rats by inhibiting the expression of HIF-1α and PCNA and reducing pulmonary vascular remodeling. Citation:Chinese Journal of Contemporary Pediatrics, 2024, 26(7): 757-764.

Bronchopulmonary Dysplasia-Associated Pulmonary Hypertension: Basing Care on Physiology

Bronchopulmonary dysplasia (BPD) is the heterogeneous chronic lung developmental disease of prematurity, which is often accompanied by multisystem comorbidities. Pulmonary vascular disease and pulmonary hypertension (PH) contribute significantly to the pathogenesis and pathophysiology of BPD and dramatically influence the outcomes of preterm infants with BPD. When caring for those patients, clinicians should consider the multitude of phenotypic presentations that fall under the "BPD-PH umbrella," reflecting the need for matching therapies to specific physiologies to improve short- and long-term outcomes. Individualized management based on the patient's prenatal and postnatal risk factors, clinical course, and cardiopulmonary phenotype needs to be identified and prioritized to provide optimal care for infants with BPD-PH.

Risk Factors and Mortality in Newborns with Persistent Pulmonary Hypertension: A Six-Year Single-Center Experience

Objectives

Persistent pulmonary hypertension (PPHT) of the newborn is a disorder of circulatory transition resulting in high pulmonary vascular resistance with extrapulmonary right-to-left shunts causing hypoxemia. In this study, our aim was to evaluate the risk factors, administered treatments, and mortality of patients followed in our neonatal intensive care unit (NICU) due to PPHT over the past six years.

Methods

Patients diagnosed with PPHT and followed in the NICU between January 2017 and November 2022 were included in the study. The sociodemographic characteristics, diagnoses that could lead to pulmonary hypertension, the presence of congenital anomalies, the duration of respiratory support treatment and hospital follow-up, treatments administered for PPHT, and mortality rates were evaluated.

Results

Out of 21 patients diagnosed with persistent pulmonary hypertension, 9 of them (42.9%) were male. The mean gestational age of the patients was 37.6±3.7 weeks, and their birth weight was 3006±819grams. The APGAR scores at 1 and 5 minutes were 4(2-7) and 6(3-8), respectively. Risk factors during the antenatal period included fetal distress (38.1%), oligohydramnios (23.8%), intrauterine growth restriction (23.8%), gestational diabetes (14.3%), preeclampsia (4.8%), and chorioamnionitis (4.8%). The median duration of invasive mechanical ventilation for cases requiring respiratory support was 20.1 days, while the median duration of non-invasive ventilation was 3.7 days. Patients with a diagnosis of persistent pulmonary hypertension were treated with inhaled nitric oxide (iNO) in 76.2% of cases, milrinone in 66.7% of cases, sildenafil in 52.4% of cases, and iloprost in 14.3% of cases. The length of hospital stay for patients was 38.4 days, and 9 (42.9%) patients died. The patients who died had severe PPHT along with fetal inflammatory response syndrome (FIRS), congenital heart disease, pulmonary hypoplasia, pneumothorax, hypoxic-ischemic encephalopathy (HIE), and congenital anomalies.

Conclusion

Persistent pulmonary hypertension, characterized by severe hypoxemia, is a neonatal emergency that necessitates early intervention, effective treatment of the underlying cause to prevent potential short-term and long-term morbidities and mortality. Effective treatment of the underlying cause in patients diagnosed with PPHT could reduce morbidity and mortality. It is inevitable to avoid the loss of patients with major abnormalities, severe comorbidities, and unpreventable organ dysfunctions.

Occurrence of hyperoxia during iNO treatment for persistent pulmonary hypertension of the newborn: a cohort study

High concentrations of oxygen are often needed to optimize oxygenation in infants with persistent pulmonary hypertension (PPHN), but this can also increase the risk of hyperoxemia. We determined the occurrence of hyperoxemia in infants treated for PPHN. Medical records of infants ≥ 34 + 0 weeks gestational age (GA) who received inhaled nitric oxide (iNO) were retrospectively reviewed for oxygenation parameters during iNO therapy. Oxygen was manually titrated to target arterial oxygen tension (PaO2) 10-13 kPa and peripheral oxygen saturation (SpO2) 92-98%. The main study outcomes were the incidence and duration of hyperoxemia and hypoxemia and the fraction of inspired oxygen (FiO2). A total of 181 infants were included. The median FiO2 was 0.43 (IQR 0.34-0.56) and the maximum FiO2 was 1.0 in 156/181 (86%) infants, resulting in at least one PaO2 > 13 kPa in 149/181 (82%) infants, of which 46/149 (31%) infants had minimal one PaO2 > 30 kPa. SpO2 was > 98% in 179/181 (99%) infants for 17.7% (8.2-35.6%) of the iNO time. PaO2 < 10 kPa occurred in 160/181 (88%) infants, of which 81/160 (51%) infants had minimal one PaO2 < 6.7 kPa. SpO2 was < 92% in 169/181 (93%) infants for 1.6% (0.5-4.3%) of the iNO time.    Conclusion: While treatment of PPHN is focused on preventing and reversing hypoxemia, hyperoxemia occurs inadvertently in most patients. What is Known: • High concentrations of oxygen are often needed to prevent hypoxemia-induced deterioration of PPHN, but this can also increase the risk of hyperoxemia. • Infants with persistent pulmonary hypertension may be particularly vulnerable to the toxic effects of oxygen, and hyperoxemia could further induce pulmonary vasoconstriction, potentially worsening the condition. What is New: • Hyperoxemia occurs in the majority of infants with PPHN during treatment with iNO. • Infants with PPHN spent a considerably longer period with saturations above the target range compared to saturations below the target range.

Mitochondrial network dynamics in pulmonary disease: Bridging the gap between inflammation, oxidative stress, and bioenergetics

Once thought of in terms of bioenergetics, mitochondria are now widely accepted as both the orchestrator of cellular health and the gatekeeper of cell death. The pulmonary disease field has performed extensive efforts to explore the role of mitochondria in regulating inflammation, cellular metabolism, apoptosis, and oxidative stress. However, a critical component of these processes needs to be more studied: mitochondrial network dynamics. Mitochondria morphologically change in response to their environment to regulate these processes through fusion, fission, and mitophagy. This allows mitochondria to adapt their function to respond to cellular requirements, a critical component in maintaining cellular homeostasis. For that reason, mitochondrial network dynamics can be considered a bridge that brings multiple cellular processes together, revealing a potential pathway for therapeutic intervention. In this review, we discuss the critical modulators of mitochondrial dynamics and how they are affected in pulmonary diseases, including chronic obstructive pulmonary disease (COPD), idiopathic pulmonary fibrosis (IPF), acute lung injury (ALI), and pulmonary arterial hypertension (PAH). A dysregulated mitochondrial network plays a crucial role in lung disease pathobiology, and aberrant fission/fusion/mitophagy pathways are druggable processes that warrant further exploration. Thus, we also discuss the candidates for lung disease therapeutics that regulate mitochondrial network dynamics.

Pulmonary Vascular Regulation in the Fetal and Transitional Lung

Fetal lungs have fewer and smaller arteries with higher pulmonary vascular resistance (PVR) than a newborn. As gestation advances, the pulmonary circulation becomes more sensitive to changes in pulmonary arterial oxygen tension, which prepares them for the dramatic drop in PVR and increase in pulmonary blood flow (PBF) that occur when the baby takes its first few breaths of air, thus driving the transition from fetal to postnatal circulation. Dynamic and intricate regulatory mechanisms control PBF throughout development and are essential in supporting gas exchange after birth. Understanding these concepts is crucial given the role the pulmonary vasculature plays in the development of complications with transition, such as in the setting of persistent pulmonary hypertension of the newborn and congenital heart disease. An improved understanding of pulmonary vascular regulation may reveal opportunities for better clinical management.

Efficacy of inhaled nitric oxide in preterm infants ≤ 34 weeks: a systematic review and meta-analysis of randomized controlled trials

Background: The effect of inhaled nitric oxide (iNO) in neonates >34 weeks on improving respiration is well documented. However, the efficacy of iNO in preterm infants ≤34 weeks remains controversial. Objectives: The main purpose of this review is to assess the effectiveness and safety of iNO treatment in preterm infants ≤34 weeks. Search methods: We systematically searched PubMed, Embase and Cochrane Libraries from their inception to 1 June 2023. We also reviewed the reference lists of retrieved studies. Selection criteria: Our study involved randomized controlled trials on preterm infants ≤34 weeks, especially those receiving iNO treatment, and mainly assessed outcomes such as bronchopulmonary dysplasia (BPD) and mortality. Two authors independently reviewed these trials, extracted data, and evaluated study biases. Disagreements were resolved by consensus. We used the GRADE method to assess evidence quality. Results: Our research included a total of 17 studies involving 4,080 neonates and 7 follow-up studies. The synthesis of results showed that in neonates, iNO treatment reduced the incidence of BPD (RR: 0.92; 95% CI: 0.86-0.98). It also decreased the composite outcome of death or BPD (RR: 0.94; 95% CI: 0.90-0.98), without increasing the risk of short-term (such as intraventricular hemorrhage, periventricular leukomalacia) and long-term neurological outcomes (including Bayley mental developmental index <70, cerebral palsy and neurodevelopmental impairment). Furthermore, iNO did not significantly affect other neonatal complications like sepsis, pulmonary hemorrhage, necrotizing enterocolitis, and symptomatic patent ductus arteriosus. Subgroup analysis revealed that iNO significantly reduced BPD incidence in neonates at 36 weeks under specific intervention conditions, including age less than 3 days, birth weight over 1,000 g, iNO dose of 10 ppm or higher, or treatment duration exceeding 7 days (p < 0.05). Conclusion: Inhaled NO reduced the incidence of BPD in neonates at 36 weeks of gestation, and the effect of the treatment depended on neonatal age, birth weight, duration and dose of iNO. Therefore, iNO can be considered a promising treatment for the potential prevention of BPD in premature infants. More data, however, would be needed to support nitric oxide registration in this specific patient population, to minimize its off-label use.

Case Report: Stüve-Wiedemann syndrome-a rare cause of persistent pulmonary hypertension of the newborn

Introduction

Persistent pulmonary hypertension of the newborn (PPHN) is a life-threatening condition characterized by hypoxemia due to elevated pulmonary vascular resistance. PPHN commonly arises secondary to various underlying conditions, including infection, meconium aspiration, and respiratory distress syndrome. Management includes pulmonary vasodilators, mechanical ventilation, oxygen supplementation, vasopressors, and volume replacement. Stüve-Wiedemann syndrome (SWS), a rare genetic disorder characterized by bone dysplasia, respiratory distress, hyperthermia, and swallowing difficulties, may present with pulmonary hypertension, indicating a poor prognosis.

Case description

A term female neonate presented with secondary respiratory failure and severe PPHN of unknown etiology on the second day of life, necessitating intubation. Clinical findings included facial dysmorphia, camptodactyly, skeletal anomalies, and generalized muscular hypotonia. High-frequency oscillation ventilation and surfactant administration yielded marginal improvement. On the third day of life, a severe pulmonary hypertensive crisis necessitated inhaled and systemic pulmonary vasodilators along with volume and catecholamine therapy. Whole exome sequencing revealed a homozygous mutation in the leukemia inhibitory factor receptor (LIFR) gene, consistent with Stüve-Wiedemann syndrome.

Discussion/conclusion

The case underscores the importance of considering and prompting evaluation of rare genetic causes in the differential diagnosis of PPHN, especially when other abnormalities are present and conventional therapies prove inadequate. Therapeutic strategies must account for the different pathophysiology of primary PPHN including vascular remodeling, as seen in SWS, which may not respond to pulmonary vasodilators typically employed in secondary PPHN due to vasoconstriction. In this case, the patient responded well to treatment for primary PPHN, but the use of high-frequency oscillation ventilation and surfactant was not helpful.

Long-Term Effect of TBX4 Germline Mutation on Pulmonary Clinico-Histopathologic Phenotype

Tbx4 protein, expressed in mesenchyme of the developing lung, contributes to airway branching and distal lung growth. An association between pediatric onset of pulmonary arterial hypertension (PAH) and genetic variations coding for the T-box transcription factor 4 gene (TBX4) has been increasingly recognized. Tbx4-related PAH onset has a bimodal age distribution, including severe to lethal PAH in newborns and later onset PAH. We present an autopsy study of a 24-year-old male with a heterozygous TBX4 variant, who developed pulmonary arterial hypertension at age 12 years. This unique case highlights the complex pulmonary histopathology leading to lethal cardiopulmonary failure in the setting of TBX4 mutation.

Evidence-Based Guidelines for Acute Stabilization and Management of Neonates with Persistent Pulmonary Hypertension of the Newborn

Persistent pulmonary hypertension of the newborn, or PPHN, represents a challenging condition associated with high morbidity and mortality. Management is complicated by complex pathophysiology and limited neonatal specific evidence-based literature, leading to a lack of universal contemporary clinical guidelines for the care of these patients. To address this need and to provide consistent high-quality clinical care for this challenging population in our neonatal intensive care unit, we sought to develop a comprehensive clinical guideline for the acute stabilization and management of neonates with PPHN. Utilizing cross-disciplinary expertise and incorporating an extensive literature search to guide best practice, we present an approachable, pragmatic, and clinically relevant guide for the bedside management of acute PPHN. KEY POINTS: · PPHN is associated with several unique diagnoses; the associated pathophysiology is different for each unique diagnosis.. · PPHN is a challenging, dynamic, and labile process for which optimal care requires frequent reassessment.. · Key management goals are adequate tissue oxygen delivery, avoiding harm..

[Recent research on inhaled nitric oxide in preterm infants with a gestational age of <34 weeks]

Nitric oxide is a messenger molecule for vasodilation of vascular smooth muscle cells, and inhaled nitric oxide (iNO) can dilate pulmonary blood vessels and reduce pulmonary vascular resistance, thereby reducing pulmonary artery pressure, but with no influence on systemic circulation pressure. Guidelines in China and overseas recommend the use of iNO in full-term infants and late preterm infants, and it has been proved that it has a marked effect on persistent pulmonary hypertension and hypoxic respiratory failure in such infants. However, recent studies have shown that there is an increase in the off-label use of iNO in preterm infants with a gestational age of <34 weeks. This article reviews the research progress on the efficacy, safety, timing, dose, and withdrawal mode of iNO and its combination with vasoactive drugs in the treatment of preterm infants with a gestational age of <34 weeks in China and overseas, so as to provide a reference for clinical application.

Recent Advances in Pediatric Pulmonary Hypertension: Implications for Diagnosis and Treatment

PURPOSE

Pediatric pulmonary hypertension (PH) is a condition characterized by elevated pulmonary arterial pressure, which has the potential to be life-limiting. The etiology of pediatric PH varies. When compared with adult cohorts, the etiology is often multifactorial, with contributions from prenatal, genetic, and developmental factors. This review aims to provide an up-to-date overview of the causes and classification of pediatric PH, describe current therapeutics in pediatric PH, and discuss upcoming and necessary research in pediatric PH.

METHODS

PubMed was searched for articles relating to pediatric pulmonary hypertension, with a particular focus on articles published within the past 10 years. Literature was reviewed for pertinent areas related to this topic.

FINDINGS

The evaluation and approach to pediatric PH are unique when compared with that of adults, in large part because of the different, often multifactorial, causes of the disease in children. Collaborative registry studies have found that the most common disease causes include developmental lung disease and subsets of pulmonary arterial hypertension, which includes genetic variants and PH associated with congenital heart disease. Treatment with PH-targeted therapies in pediatrics is often guided by extrapolation of adult data, small clinical studies in pediatrics, and/or expert consensus opinion. We review diagnostic considerations and treatment in some of the more common pediatric subpopulations of patients with PH, including developmental lung diseases, congenital heart disease, and trisomy 21.

IMPLICATIONS

The care of pediatric patients with PH requires consideration of unique pediatric-specific factors. With significant variability in disease etiology, ongoing efforts are needed to optimize treatment strategies based on disease phenotype and guide evidence-based practices.

Consensus Panel Recommendations for the Pharmacological Management of Pregnant Women with Depressive Disorders

INTRODUCTION

The initiative of a consensus on the topic of antidepressant and anxiolytic drug use in pregnancy is developing in an area of clinical uncertainty. Although many studies have been published in recent years, there is still a paucity of authoritative evidence-based indications useful for guiding the prescription of these drugs during pregnancy, and the data from the literature are complex and require expert judgment to draw clear conclusions.

METHODS

For the elaboration of the consensus, we have involved the scientific societies of the sector, namely, the Italian Society of Toxicology, the Italian Society of Neuropsychopharmacology, the Italian Society of Psychiatry, the Italian Society of Obstetrics and Gynecology, the Italian Society of Drug Addiction and the Italian Society of Addiction Pathology. An interdisciplinary team of experts from different medical specialties (toxicologists, pharmacologists, psychiatrists, gynecologists, neonatologists) was first established to identify the needs underlying the consensus. The team, in its definitive structure, includes all the representatives of the aforementioned scientific societies; the task of the team was the evaluation of the most accredited international literature as well as using the methodology of the "Nominal Group Technique" with the help of a systematic review of the literature and with various discussion meetings, to arrive at the drafting and final approval of the document.

RESULTS

The following five areas of investigation were identified: (1) The importance of management of anxiety and depressive disorders in pregnancy, identifying the risks associated with untreated maternal depression in pregnancy. (2) The assessment of the overall risk of malformations with the antidepressant and anxiolytic drugs used in pregnancy. (3) The evaluation of neonatal adaptation disorders in the offspring of pregnant antidepressant/anxiolytic-treated women. (4) The long-term outcome of infants' cognitive development or behavior after in utero exposure to antidepressant/anxiolytic medicines. (5) The evaluation of pharmacological treatment of opioid-abusing pregnant women with depressive disorders.

CONCLUSIONS

Considering the state of the art, it is therefore necessary in the first instance to frame the issue of pharmacological choices in pregnant women who need treatment with antidepressant and anxiolytic drugs on the basis of data currently available in the literature. Particular attention must be paid to the evaluation of the risk/benefit ratio, understood both in terms of therapeutic benefit with respect to the potential risks of the treatment on the pregnancy and on the fetal outcome, and of the comparative risk between the treatment and the absence of treatment; in the choice prescription, the specialist needs to be aware of both the potential risks of pharmacological treatment and the equally important risks of an untreated or undertreated disorder.

Persistent pulmonary hypertension of the newborn due to methylmalonic acidemia: a case report and review of the literature

BACKGROUND

Persistent pulmonary hypertension of the newborn manifesting with refractory and severe cyanosis is the consequence of high pulmonary vascular resistance causing extrapulmonary right-to-left shunt. Acidosis and hypoxemia produce pulmonary vasoconstriction. Persistent pulmonary hypertension of the newborn occurs due to numerous disorders and has been rarely reported as a manifestation of methylmalonic acidemia. We report a newborn with methylmalonic acidemia who presented with persistent pulmonary hypertension of the newborn.

CASE PRESENTATION

A 1-day-old Iranian girl presented with respiratory distress and refractory metabolic acidosis. She was born at 39 + 5 weeks gestational age with Apgar scores of 8 and 9 in the 1st and 5th minutes, respectively, and was in good condition up to 10 hours of life. After that, she presented with cyanosis, tachypnea, retraction, and hypotonia. Despite receiving oxygen, she had low oxygen saturation. Echocardiography revealed severe pulmonary hypertension and right-to-left shunt through patent ductus arteriosus and foramen ovale. Her acidosis worsened despite receiving full support and medical therapy. So, she was started on peritoneal dialysis. Unfortunately, she did not respond to treatment, and after she had died, biochemical tests confirmed methylmalonic acidemia.

CONCLUSION

Persistent pulmonary hypertension of the newborn is a very rare manifestation of methylmalonic acidemia. Severe inborn errors of metabolism may cause irreversible damage with adverse lifelong morbidity, and early diagnosis may help to prevent such complications. Furthermore, diagnosis of these disorders aids in prenatal diagnosis through the use of cultured amniocytes or chorionic villi to detect gene mutations, as well as biochemical analyses of amniotic fluid for subsequent pregnancies.

Elevation of Pulmonary Artery Pressure in Newborns from High-Altitude Pregnancies Complicated by Preeclampsia

We hypothesized that fetal exposure to the oxidative stress induced by the combined challenge of preeclampsia (PE) and high altitude would induce a significant impairment in the development of pulmonary circulation. We conducted a prospective study in La Paz (Bolivia, mean altitude 3625 m) in which newborns from singleton pregnancies with and without PE were compared (PE group n = 69, control n = 70). We conducted an echocardiographic study in these infants at the median age of two days. The percentage of cesarean deliveries and small for gestational age (SGA) infants was significantly higher in the PE group. Heart rate, respiratory rate, and oxygen saturation did not vary significantly between groups. Estimated pulmonary arterial pressure and pulmonary vascular resistance were 30% higher in newborns exposed to PE and high altitude compared with those exposed only to high altitude. We also detected signs of right ventricular hypertrophy in infants subjected to both exposures. In conclusion, this study provides evidence that the combination of PE and pregnancy at high altitude induces subclinical alterations in the pulmonary circulation of the newborn. Follow-up of this cohort may provide us with valuable information on the potential increased susceptibility to developing pulmonary hypertension or other pulmonary and cardiovascular disorders.

Clinical significance of correlation between persistent pulmonary hypertension and 8-hydroxy-2-desoxyguanosine level in premature newborns

BACKGROUND: Persistent pulmonary hypertension is a problem that leads to high morbidity and mortality in preterm infants. In clinical studies, oxidative stress (OS) contributes to the development of pulmonary hypertension (PH). The most specific biomarker of OS in preterm infants is urinary 8-hydroxy-2-deoxyguanosine (8-OHdG). The aim of the study was to determine the clinical correlation between the value of 8-OHdG and the level of a mean pressure in the pulmonary artery (mPAP) in premature infants with respiratory distress syndrome (RDS) and asphyxia in the early neonatal period. METHODS: Determination of the urinary 8-OHdG value and PH in 96 premature infants born at gestational age of 26–32 weeks on the 1st and the 3rd–5th days of life in two groups: group I –52 children with respiratory distress syndrome; II –44 children with RDS associated with perinatal asphyxia. RESULTS: The 2nd group of children had higher average mPAP level, mmHg, both in the 1st and in the 3rd–5th day of life compared with the 1st group. The value of the urinary 8-OHdG correlated with the manifestation of PH that required prolonged respiratory support in group II. CONCLUSION: Perinatal asphyxia in preterm infants with RDS on the 1st day of life complicates the course of PH, as indicated by a higher level of the urinary 8-OHdG and correlated to mPAP. Gender characteristics of the dynamics of 8-OHdG levels in children with perinatal pathology reveal reduced adaptability and reactivity of boys to OS at birth.

Successful treatment of pulmonary hypertension in a neonate with bronchopulmonary dysplasia: A case report and literature review

BACKGROUND

Pulmonary hypertension (PH) is a severe complication of bronchopulmonary dysplasia (BPD) in premature neonates and is closely related to prognosis. However, there is no effective and safe treatment for PH due to BPD in infants. Successful treatment for cases of BPD-associated PH with Tadalafil combined with bosentan is rare. This case may make a significant contribution to the literature because PH is difficult to manage as a serious complication of BPD in preterm infants. Mortality is high, especially when it is complicated by heart failure.

CASE SUMMARY

An extremely premature neonate with a gestational age of 26⁺⁵ wk and birth weight of 0.83 kg was diagnosed with BPD associated with PH; oral sildenafil did not improve the PH. The infant experienced sudden cardiac arrest and serious heart failure with severe PH. After a series of treatments, including cardiopulmonary resuscitation, mechanical ventilation, and inhaled nitric oxide (iNO), the respiratory and circulatory status improved but the pulmonary artery pressure remained high. Then oral sildenafil was replaced with oral tadalafil and bosentan; pulmonary artery pressure improved, and the infant recovered at our hospital. After 2 years of follow-up, she is in good condition, without any cardiovascular complications.

CONCLUSION

INO can effectively improve the respiratory and circulatory status of infants with PH associated with premature BPD. B-type natriuretic peptide should be routinely measured during hospitalization to evaluate the risk and prognosis of BPD-associated PH in preterm infants. Tadalafil combined with bosentan for the treatment of PH associated with premature BPD was better than sildenafil in this case. Further studies are needed to explore the efficacy and safety of different vasodilators in the treatment of PH associated with premature BPD.

Tricuspid regurgitation and left ventricular eccentricity as a measure of heart failure in the newborn patient with a vein of Galen malformation: illustrative case

BACKGROUND

Successful management of a vein of Galen malformation (VoGM) in the newborn patient requires a highly coordinated team approach involving neonatologists, pediatric cardiologists, pediatric neurologists, neurosurgeons, and interventionalists. Indication and timing of catheter intervention are topics of ongoing debate.

OBSERVATIONS

The authors highlighted two key echocardiographic markers believed to be practical indicators regarding the need for urgent catheter embolization in neonates with a VoGM. The first and preferred parameter was the tricuspid valve regurgitation (TR) gradient, an estimate of pulmonary artery hypertension. If the TR gradient exceeds systolic blood pressure (suprasystemic pulmonary hypertension [PH], i.e., >60 mm Hg), urgent intervention should be considered in eligible newborns. The second parameter was the left ventricular end-systolic eccentricity index (EI), a newly emerging echocardiographic marker and indirect correlate of PH. As an alternative to the TR gradient, an increased eccentricity index (>1.6) suggests severe right heart compromise, requiring emergency catheter embolization of the malformation. Postoperatively, the progressive reduction of both the TR gradient and the EI correlated with recovery.

LESSONS

In eligible newborns, urgent embolization of a VoGM is recommended in the presence of suprasystemic TR gradients and/or increased EI >1.6.

Pulmonary hypertension and oxidative stress: Where is the link?

Oxidative stress can be associated with hyperoxia and hypoxia and is characterized by an increase in reactive oxygen (ROS) and nitrogen (RNS) species generated by an underlying disease process or by supplemental oxygen that exceeds the neutralization capacity of the organ system. ROS and RNS acting as free radicals can inactive several enzymes and vasodilators in the nitric oxide pathway promoting pulmonary vasoconstriction resulting in persistent pulmonary hypertension of the newborn (PPHN). Studies in animal models of PPHN have shown high ROS/RNS that is further increased by hyperoxic ventilation. In addition, antioxidant therapy increased PaO2 in these models, but clinical trials are lacking. We recommend targeting preductal SpO2 between 90 and 97%, PaO2 between 55 and 80 mmHg and avoiding FiO2 > 0.6-0.8 if possible during PPHN management. This review highlights the role of oxidative and nitrosative stress markers on PPHN and potential therapeutic interventions that may alleviate the consequences of increased oxidant stress during ventilation with supplemental oxygen.

Association of asymmetric dimethylarginine with the pathological process of persistent pulmonary hypertension of the newborn

OBJECTIVES

To study the change in asymmetric dimethylarginine (ADMA) in the circulation system of full-term infants with persistent pulmonary hypertension of the newborn (PPHN) and its association with treatment response, as well as the possibility of ADMA as a therapeutic target and a marker for treatment response.

METHODS

A prospective study was performed. A total of 30 full-term neonates who were diagnosed with PPHN within 3 days after birth were enrolled as the PPHN group, and the neonates without PPHN, matched for gestational age and age, who were treated or observed in the department of neonatology were enrolled as the control group. Serum samples were collected on days 1, 7, and 14 of treatment. The high-performance liquid chromatography-tandem mass spectrometry was used to measure the serum concentrations of L-arginine, ADMA, and its isomer symmetric dimethylarginine (SDMA).

RESULTS

For the neonates in the control group, the serum concentrations of ADMA and L-arginine continuously increased and the serum concentration of SDMA continuously decreased within the first 14 days of treatment. On days 1 and 14, there was no significant difference in the serum concentration of ADMA between the control and PPHN groups (P>0.05). On day 7, the PPHN group had a significantly higher serum concentration of ADMA than the control group (P<0.05), while there were no significant differences in serum concentrations of SDMA or L-arginine (P>0.05). Moreover, after 7 days of treatment, the PPHN neonates with a systolic pulmonary arterial pressure (sPAP) of >35 mmHg had a significantly higher serum concentration of ADMA than those with an sPAP of ≤35 mm Hg.

CONCLUSIONS

There are continuous increases in the ADMA concentration and the ADMA/SDMA ratio in the circulation system of full-term infants within the first 2 weeks after birth, and this process is accelerated by the pathological process of PPHN, suggesting that ADMA may be involved in the pathologic process of PPHN. A high level of ADMA is associated with the resistance to PPHN treatment, suggesting that inhibition of ADMA might be a potential target of drug intervention to improve the treatment response of PPHN.

Management Practices During Perinatal Respiratory Transition of Very Premature Infants

The present review considers some controversial management practices during extremely premature perinatal transition. We focus on perinatal prevention and treatment of respiratory distress syndrome (RDS) in immature infants. New concerns regarding antenatal corticosteroid management have been raised. Many fetuses are only exposed to potential adverse effects of the drug. Hence, the formulation and the dosage may need to be modified. Another challenge is to increase the fraction of the high-risk fetuses that benefit from the drug and to minimize the harmful effects of the drug. On the other hand, boosting anti-inflammatory and anti-microbial properties of surfactant requires further attention. Techniques of prophylactic surfactant administration to extremely immature infants at birth may be further refined. Also, new findings suggest that prophylactic treatment of patent ductus arteriosus (PDA) of a high-risk population rather than later selective closure of PDA may be preferred. The TREOCAPA trial (Prophylactic treatment of the ductus arteriosus in preterm infants by acetaminophen) evaluates, whether early intravenous paracetamol decreases the serious cardiorespiratory consequences following extremely premature birth. Lastly, is inhaled nitric oxide (iNO) used in excess? According to current evidence, iNO treatment of uncomplicated RDS is not indicated. Considerably less than 10% of all very premature infants are affected by early persistence of pulmonary hypertension (PPHN). According to observational studies, effective ventilation combined with early iNO treatment are effective in management of this previously fatal disease. PPHN is associated with prolonged rupture of fetal membranes and birth asphyxia. The lipopolysaccharide (LPS)-induced immunotolerance and hypoxia-reperfusion-induced oxidant stress may inactivate NO-synthetases in pulmonary arterioles and terminal airways. Prospective trials on iNO in the management of PPHN are indicated. Other pulmonary vasodilators may be considered as comparison drugs or adjunctive drugs. The multidisciplinary challenge is to understand the regulation of pregnancy duration and the factors participating the onset of extremely premature preterm deliveries and respiratory adaptation. Basic research aims to identify deficiencies in maternal and fetal tissues that predispose to very preterm births and deteriorate the respiratory adaptation of immature infants. Better understanding on causes and prevention of extremely preterm births would eventually provide effective antenatal and neonatal management practices required for the intact survival.

Fatal accidental lipid overdose with intravenous composite lipid emulsion in a premature newborn: a case report

BACKGROUND

Tenfold or more overdose of a drug or preparation is a dreadful adverse event in neonatology, often due to an error in programming the infusion pump flow rate. Lipid overdose is exceptional in this context and has never been reported during the administration of a composite intravenous lipid emulsion (ILE).

CASE PRESENTATION

Twenty-four hours after birth, a 30 weeks' gestation infant with a birthweight of 930 g inadvertently received 28 ml of a composite ILE over 4 h. The ILE contained 50% medium-chain triglycerides and 50% soybean oil, corresponding to 6 g/kg of lipids (25 mg/kg/min). The patient developed acute respiratory distress with echocardiographic markers of pulmonary hypertension and was treated with inhaled nitric oxide and high-frequency oscillatory ventilation. Serum triglyceride level peaked at 51.4 g/L, 17 h after the lipid overload. Triple-volume exchange transfusion was performed twice, decreasing the triglyceride concentration to < 10 g/L. The infant's condition remained critical, with persistent bleeding and shock despite supportive treatment and peritoneal dialysis. Death occurred 69 h after the overdose in a context of refractory lactic acidosis.

CONCLUSIONS

Massive ILE overdose is life-threatening in the early neonatal period, particularly in premature and hypotrophic infants. This case highlights the vigilance required when ILEs are administered separately from other parenteral intakes. Exchange transfusion should be considered at the first signs of clinical or biological worsening to avoid progression to multiple organ failure.

Persistent Pulmonary Hypertension: A Look Into the Future Therapy

Persistent pulmonary hypertension (PPHN) of the newborn is a lung parenchymal disorder that causes a wide range of hemodynamic changes in the newborn's systemic circulation. Arising from a multifactorial web of etiology, PPHN is one of the most common reasons for neonatal intensive care unit hospitalization and is associated with increased morbidity and mortality. Historically, multiple treatment modalities have been explored, ranging from oxygen and surfactant therapy to newer upcoming medications like magnesium sulfate and adenosine. This review article has discussed the pathogenesis of PPHN and its relationship with the clinical implications of PPHN, such as heart failure and so on. This article has also explored the diagnostic guidelines and analyzed the existing and the upcoming modalities for treating PPHN.

Best pre-ductal PaO2 prior to extracorporeal membrane oxygenation as predictor of mortality in patients with congenital diaphragmatic hernia: a retrospective analysis of a Japanese database

PURPOSE

Predicting lethal pulmonary hypoplasia in infants with congenital diaphragmatic hernia (CDH) before extracorporeal membrane oxygenation (ECMO) initiation is difficult. This study aimed to predict lethal pulmonary hypoplasia in patients with CDH prior to ECMO.

METHODS

This was a multicenter cohort study involving neonates prenatally diagnosed with isolated unilateral CDH (born 2006-2020). Patients who required ECMO due to respiratory insufficiency were included in this study. Patients who underwent ECMO due to transient disorders were excluded from analysis. Blood gas analysis data within 24 h of birth were compared between survivors and non-survivors. Predictive abilities were assessed for factors with significant differences.

RESULTS

Overall, 34 patients were included (18 survivors and 16 non-survivors). The best pre-ductal PaO₂ was significantly lower in non-survivors than in survivors (50.4 [IQR 30.3-64.5] vs. 67.5 [IQR 52.4-103.2] mmHg, respectively; p = 0.047). A cutoff PaO₂ of 42.9 mmHg had a sensitivity, specificity, and positive predictive value of 50.0%, 94.4%, and 88.9%, respectively, to predict mortality.

CONCLUSION

The best PaO₂ within 24 h after birth predicted mortality following ECMO initiation. This should be shared to families and caregivers to optimize the best interests of the infants with CDH.