Patent ductus arteriosus in the preterm infant: to treat or not to treat?

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.

Impact of Nutritional Status on Total Brain Tissue Volumes in Preterm Infants

Preterm infants bypass the crucial in utero period of brain development and are at increased risk of malnutrition. We aimed to determine if their nutritional status is associated with brain tissue volumes at term equivalent age (TEA), applying recently published malnutrition guidelines for preterm infants. We performed a single center retrospective chart review of 198 infants < 30 weeks' gestation between 2018 and 2021. We primarily analyzed the relationship between the manually obtained neonatal MR-based brain tissue volumes with the maximum weight and length z-score. Significant positive linear associations between brain tissue volumes at TEA and weight and length z-scores were found (p < 0.05). Recommended nutrient intake for preterm infants is not routinely achieved despite efforts to optimize nutrition. Neonatal MR-based brain tissue volumes of preterm infants could serve as objective, quantitative and reproducible surrogate parameters of early brain development. Nutrition is a modifiable factor affecting neurodevelopment and these results could perhaps be used as reference data for future timely nutritional interventions to promote optimal brain volume.

Correlation between the Closure Time of Patent Ductus Arteriosus in Preterm Infants and Long-Term Neurodevelopmental Outcome

In patent ductus arteriosus (PDA) in preterm infants, the relationship between treatment timing and long-term developmental prognosis remains unclear. The purpose of this study was to clarify the relationship between the age in days when ductus arteriosus closure occurred and long-term development. Preterm infants with a birth weight of less than 1500 g who were admitted to our NICU over a period of 9 years (2011-2019) and were diagnosed with PDA were included. A new version of the K-type developmental test for corrected ages of 1.5 and 3 years was used as an index of development. The relationship between the duration of PDA and the developmental index was evaluated using Pearson's correlation coefficient, and multiple regression analysis was performed. Development quotient (DQ) at the ages of 1.5 and 3 years showed a correlation with the PDA closure date and the standard deviation (SD) value of the term birth weight. Multiple regression analysis showed a positive correlation of the DQ at 1.5 and 3 years with the SD value of the term birth weight and a negative correlation with the PDA closure date. In addition, a stronger correlation was found in the "posture/motor" sub-item at 3 years. On the other hand, the analysis including preterm infants without PDA showed that preterm infants with PDA closure on the 6th day or later after birth had a significantly lower 3-year-old DQ than preterm infants with a PDA exposure within 5 days. In conclusion, it is suggested that the decrease in cerebral blood flow due to PDA in preterm infants has an adverse effect on long-term neurodevelopment. Appropriate interventions, including surgical treatment for PDA in preterm infants without delay, ideally within 5 days of birth, may be effective in improving the developmental prognosis.

[Risk factors and prognosis of hypotension within 72 hours after birth in extremely preterm infants]

OBJECTIVES

To investigate the risk factors and prognosis of hypotension within 72 hours after birth in extremely preterm infants.

METHODS

A retrospective analysis was conducted on clinical data of extremely preterm infants admitted to the Children's Hospital of Zhejiang University School of Medicine from January 2019 to April 2022. Based on the presence of hypotension within 72 hours after birth, the eligible infants were divided into a hypotension group (41 cases) and a normotension group (82 cases). The clinical characteristics, echocardiographic parameters within 72 hours after birth, and early complications were compared between the two groups. Multivariate logistic regression analysis was used to explore the risk factors for hypotension within 72 hours after birth, and receiver operating characteristic curve analysis was performed to evaluate the predictive value of relevant indicators for the occurrence of hypotension within 72 hours after birth in the preterm infants.

RESULTS

The proportion of infants who required medication or surgical closure of patent ductus arteriosus (PDA), the proportions of infants with intraventricular hemorrhage ≥ grade III and severe pulmonary hemorrhage, and the mortality rate within 7 days in the hypotension group were significantly higher than those in the normotension group (P<0.05). Multivariate logistic regression analysis showed that lower birth weight, larger PDA diameter, and hemodynamically significant PDA were risk factors for the occurrence of hypotension within 72 hours after birth in extremely preterm infants (P<0.05). The receiver operating characteristic curve analysis showed that the combination of birth weight, PDA diameter, and hemodynamically significant PDA had an area under the curve of 0.873 (95%CI: 0.802-0.944, P<0.05) for predicting hypotension within 72 hours after birth, with a sensitivity of 73.2% and specificity of 91.5%.

CONCLUSIONS

Hypotension within 72 hours after birth is closely related to birth weight and PDA, and increases the risk of early severe complications and mortality in extremely preterm infants.

A Global Perspective on PDA Management in the Extremely Premature: Shifting Trend Toward Transcatheter Closure

Patent ductus arteriosus (PDA) is a frequently encountered defect in infants born extremely premature (≤26 weeks' gestation). Historically, closure of the PDA was performed using cyclooxygenase inhibitor medications or by surgical ligations. However, the benefits of PDA closure using these therapies have never been demonstrated, albeit studies have previously not focused on the extremely premature infants. Therefore, there was a worldwide trend toward conservative management of the PDA. With improved survival of extremely premature infants, comorbidities associated with the PDA has increased, resulting in finding alternate treatments such as transcatheter patent ductus arteriosus closure (TCPC) for this population. Currently, there is a renewed interest toward selective treatment of the PDA in this high-risk cohort of small infants. This Comprehensive Review article inspects the globally changing trends in the management of the PDA in premature infants, with a special focus on the rising adoption of TCPC. Moreover, this article compiles data from several neonatal networks worldwide to help understand the problem at hand. Understanding the current management of premature infants and their outcomes is fundamentally essential if pediatric cardiologists are to offer TCPC as a viable therapeutic option for this population. This article aims to serve as a guide for pediatric cardiologists on this topic by compiling the results on landmark clinical trials on PDA management and the controversies that arise from these trials. Comparative outcomes from several countries are presented, including interpretations and opinions of the data from experts globally. This is a step toward coming to a global consensus in PDA management in premature infants.

Echocardiographic parameters predicting spontaneous closure of ductus arteriosus in preterm infants

Objective

To evaluate the value of echocardiographic parameters in predicting early spontaneous closure of ductus arteriosus in premature infants.

Methods

222 premature infants admitted to the neonatal ward of our hospital were selected, and patent ductus arteriosus was detected by echocardiography 48 h after birth. On the 7th day, whether the ductus arteriosus was closed naturally in this cohort was observed. The infants whose ductus arteriosus were not closed were identified as the PDA group (n = 109), and the other infants were included in the control group (n = 113). The echocardiographic parameters of the two groups of premature infants at 48 h after birth were single-factor statistically and Pearson correlation analyzed, and the parameters with statistically significant differences in single-factor analyzed were selected for multivariate logistic stepwise regression analysis.

Results

The ductus arteriosus shunt velocity and the pressure difference between the descending aorta and the pulmonary artery (ΔPs) in the PDA group were lower than those in the control group (P < 0.05). The pulmonary artery pressure (PASP) in the PDA group was higher than that in the control group (P < 0.05). According to the multivariate logistic stepwise regression analysis, only the maximum shunt velocity of ductus arteriosus was correlated with early spontaneous closure of ductus arteriosus in 48 h first echocardiographic parameters (P = 0.049). The receiver operating characteristic (ROC) curve indicates the optimal critical point of echocardiographic ductus arteriosus shunt velocity in premature infants 48 h after birth was 1.165 m/s.

Conclusion

Echocardiographic parameters are of great value in predicting the early spontaneous closure of ductus arteriosus in premature infants. In particular, the ductus arteriosus shunt velocity is correlated with the early spontaneous closure of ductus arteriosus.

Fechamento Percutâneo do Canal Arterial em Pacientes Prematuros Abaixo de 2 Kg: Experiência Inicial Brasileira

Fundamento

A incidência de ductus arteriosus patente (PCA) pode chegar a 50% em pacientes prematuros. Quando hemodinamicamente significativo, pode ser responsável por tempo de ventilação mecânica prolongado, além de importante fator de risco para o aparecimento de enterocolite necrotizante, hemorragia intraventricular e displasia broncopulmonar nessa população.

Objetivo

O objetivo deste estudo é descrever a experiência inicial do fechamento percutâneo de canal arterial em prematuros pesando menos de 2 kg.

Métodos

Trata-se de estudo prospectivo que compreendeu 14 pacientes consecutivos submetidos a fechamento percutâneo de canal arterial de março de 2020 a fevereiro de 2021 em 6 instituições no Brasil.

Resultados

A idade gestacional média ao nascimento foi de 28,45 ±3,14 semanas, a idade média no momento do procedimento foi de 38,85 ±17,35 dias e o peso médio de 1,41±0,41 kg. Dentre os prematuros, 79% necessitavam de ventilação mecânica e 79% tinham feito uso de, em média, 1,5 ciclos de anti-inflamatórios não esteroides. A maioria dos pacientes teve melhora dos parâmetros ventilatórios e o tempo médio de extubação foi de 12,6 ±7,24 dias. A taxa de sucesso foi de 100%. Não houve mortalidade relacionada ao procedimento.

Conclusão

Este estudo concluiu que o fechamento percutâneo do canal arterial em prematuros é uma realidade no Brasil, com resultados satisfatórios e baixa taxa de complicações.

Predictive Tool for Closure of Ductus Arteriosus with Pharmacologic or Surgical Treatment in Preterm Infants

To construct a model with the indices obtained by echocardiography to predict whether patent ductus arteriosus (PDA) was required to be treated with pharmacologic treatment or surgical ligation, we performed a prospective observational study, including all neonates with gestational age ≤ 30 weeks and assessed the hemodynamics of PDA by serial daily echocardiography examination at postnatal age of 0-12 h, 24 h, 48 h, and 72 h, respectively. The infants were classified in two groups based on whether they were treated with non-steroidal anti-inflammatory drugs (NSAIDs) and/or surgical ligation to close the PDA from the second week after birth. We compared the echocardiographic indices between the two groups and utilized the indices to construct a model to predict which premature infants' PDA requires intervention. The results showed that a total of forty-two preterm infants were enrolled in the study. 15 (35.7%) preterms were in the intervention group and 27 (64.3%) preterms were in the non-intervention group. Compared with the non-intervention group, the intervention group had a higher proportion of left ventricular volume overload and systemic shunt effect. In addition, the combined indicators of PDA size/weight > 3.2 mm/kg and LA/Ao > 1.4 at postnatal age of 72 h had a highest value to predict whether PDA requires intervention. These findings denoted that serial daily echocardiographic assessment can be useful in predicting whether a PDA will be closed with NSAIDs and/or surgical ligation in preterm infants with gestational age ≤ 30 weeks.Trial registration Number: IRB No. 2018-IRB-073. Date: 2018/09/21, retrospectively registered.

Brain and renal oxygenation measured by NIRS related to patent ductus arteriosus in preterm infants: a prospective observational study

Background

Patent ductus arteriosus (PDA) is common among preterm neonates. Haemodynamically significant ductus arteriosus (hsPDA) can cause ductal steal and contribute to poor outcomes. Our aim was to evaluate ductus arteriosus patency and significance using two-site near-infrared spectroscopy (NIRS) measurements in preterm infants older than 72 h as a supplemental tool to echocardiography.

Methods

In this prospective observational study, 123 preterm infants (gestational age (GA) < 32 weeks, birth weight < 1500 g) were enrolled. Sixty-four newborns had closed ductus arteriosus (noPDA), and 41 and 18 patients were assigned to the PDA and hsPDA groups, respectively, per predefined echocardiographic criteria. Cerebral and renal oxygenation were assessed during NIRS monitoring.

Results

A higher renal mean (±SD) regional tissue oxygen saturation (rSpO₂) (76.7 (±7.64)) was detected in the noPDA group than in the PDA (71.7 (±9.02)) and hsPDA (67.4 (±13.48)) groups (p < 0.001). Renal fractional tissue oxygen extraction (FTOE) (0.18 (±0.079)) was lower in the noPDA group than in the PDA (0.23 (±0.092)) and hsPDA (0.24 (±0.117))0.117 groups (p = 0.002). Cerebral oxygenation was significantly lower in the hsPDA group (77.0 (±5.16)) than in the noPDA (79.3 (±2.45)) and PDA (79.7 (±2.27)) groups (p = 0.004). There was no significant difference in cerebral fractional tissue oxygen extraction (FTOE) between any of the groups.

Conclusions

Our results suggest that renal oxygenation is affected by ductus patency in preterm infants older than 72 h. Significant differences in cerebral oxygenation were observed between the hsPDA group and the PDA and noPDA groups.

Trial registration

ClinicalTrials.gov Identifier: NCT04295395. Registration date: 4 March 2020. This study was retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT04295395.

Retrospective comparison of death or neurodevelopmental outcomes in extremely low birth weight preterm infants following different management options of haemodynamically significant patent ductus arteriosus

BACKGROUND

Optimal management of haemodynamically significant patent ductus arteriosus (HsPDA) in premature babies remains controversial. Our aim is to compare death and/or adverse neurodevelopmental outcomes in extremely low birth weight (ELBW) infants with HsPDA who were managed with conservative [C], medical [M] and/or surgical [S] treatment, with secondary aim to examine short-term morbidities among [S] and [C] groups. The study also compared outcomes in very low birth weight (VLBW) infants with HsPDA and non-HsPDA.

METHODS

A retrospective study of VLBW preterm infants born before 29 weeks in Singapore from 2007 to 2016 was conducted.

RESULTS

A total of 474 VLBW infants were admitted in NUH from 2007 to 2016. Infants aged between 24 + 0 and 28 + 6 weeks of gestation, weighing ≤1500 g and diagnosed with patent ductus arteriosus (PDA) were included in the study, of which 172 infants (124 HsPDA and 48 non-HsPDA) were analyzed. Among infants with HsPDA, 17 infants were managed with [C], 83 with [M] and 24 with [S]. Mortality was not increased regardless of the presence of HsPDA or treatment received. Infants with non-HsPDA were less likely to have isolated speech delay (p < 0.05), but not global developmental delay (GDD). No significant differences in neurodevelopmental outcomes such as hearing loss, cerebral palsy (CP) and speech delay were found. [M + S] infants were at a higher risk of developing chronic lung disease (CLD) (OR 6.83, p < 0.05) and short-term growth failure compared to [C] infants. They were significantly shorter and had a smaller head circumference at discharge (p < 0.05). [M + S] infants also had elevated creatinine compared to those in group [C] (81.1 ± 24.1 vs 48.3 ± 11.8 umol/L, p < 0.000).

CONCLUSIONS

Compared to conservative management, infants requiring [M + S] treatment for HsPDA were more likely to have short-term complications such as CLD, elevated creatinine, and poorer growth. Despite a more turbulent postnatal course, death and/or adverse neurodevelopmental outcomes were not worse in infants managed with [M + S].

The often forgotten systemic effects of ductus arteriosus: impact on decision-making and future trials

Respiratory symptomatology and echocardiographic features of pulmonary circulation exclusively guide therapy for a hemodynamically significant patent ductus arteriosus in preterm infants. Interrogations of systemic artery Doppler or the exploration of their links with respective end organ symptomatology is not routine practice. This brief report shows the relevance of 'systemic' symptoms and the assessment of 'systemic hypo-perfusion' (and their resolution with physiologically appropriate therapy) in decision-making. Future trials should include this often-ignored aspect in study designs and/or post-hoc analysis.

Protective factors against preterm infants to develop significant patent ductus arteriosus

BACKGROUND

Identifying preterm infants with a higher likelihood of spontaneous patent ductus arteriosus (PDA) closure would be desirable. This study aimed to examine daily PDA status during the first week of life for very low birthweight (VLBW, <1500 g) preterm infants and to develop a scoring system to predict spontaneous PDA closure.

METHODS

We enrolled VLBW infants admitted between January 2016 and January 2017 and performed daily echocardiographic screening for PDA existence. Oxygen index (OI, mean airway pressure × fraction of inspired oxygen/partial pressure of arterial oxygen) was applied to represent the respiratory condition.

RESULTS

A total of 215 VLBW infants were enrolled, and the accumulative incidence of spontaneous PDA closure by age 1 week was 80%, 70%, and 34% for infants born of gestational age (GA) ≥30, 28-29, and ≤27 weeks, respectively. Of these 215 infants, 184 infants entered the second phase to establish the scoring system. Infants with spontaneous PDA closure were more mature (GA 29.2 ± 2.3 vs. 26.9 ± 2.3 weeks, p < 0.001), had lower OI (2.8 ± 2.2 vs. 5.6 ± 5.3, p < 0.001) and were less likely to need endotracheal intubation (23% vs. 68%, p < 0.001). Using the receiver operating characteristics curve, OI <2.5 was determined favoring higher PDA closure incidence. The score was calculated based on the odds ratio generated in multiple regression: 4, 3 and 1 points for GA ≥30, 28-29 and ≤27 weeks, 2 and 1 points for OI <2.5 and ≥2.5, and 3 and 1 points for without and with endotracheal intubation. Using score ≥6 to predict PDA closure, the sensitivity and specificity were 0.77 and 0.72.

CONCLUSION

A score made up of GA, OI and need for intubation was proposed to predict spontaneous PDA closure by age 1 week, which could be helpful to clinicians in the management of PDA in preterm infants.

Neuroprotection of the Perinatal Brain by Early Information of Cerebral Oxygenation and Perfusion Patterns

Abnormal patterns of cerebral perfusion/oxygenation are associated with neuronal damage. In preterm neonates, hypoxemia, hypo-/hypercapnia and lack of cerebral autoregulation are related to peri-intraventricular hemorrhages and white matter injury. Reperfusion damage after perinatal hypoxic ischemia in term neonates seems related with cerebral hyperoxygenation. Since biological tissue is transparent for near infrared (NIR) light, NIR-spectroscopy (NIRS) is a noninvasive bedside tool to monitor brain oxygenation and perfusion. This review focuses on early assessment and guiding abnormal cerebral oxygenation/perfusion patterns to possibly reduce brain injury. In term infants, early patterns of brain oxygenation helps to decide whether or not therapy (hypothermia) and add-on therapies should be considered. Further NIRS-related technical advances such as the use of (functional) NIRS allowing simultaneous estimation and integrating of heart rate, respiration rate and monitoring cerebral autoregulation will be discussed.

Surgical Treatment for Patent Ductus Arteriosus: Our Experience of 12 Years

Introduction

Patent ductus arteriosus (PDA) is a congenital heart disease that, if left untreated, can lead to pulmonary hypertension, congestive heart failure, and death. Here, we aimed to assess postoperative cardiac hemodynamic changes and surgical techniques, as well as early and late postoperative findings in surgically treated PDA patients.

Materials and methods

We retrospectively analyzed the data belonging to 126 patients whose PDA was surgically closed in our clinic from January 2001 to December 2012. With echocardiography being a standard in diagnosis and follow-up, angiography and computed tomography were also used in the presence of pulmonary hypertension and congenital heart disease, when needed. Postoperative data were compared between isolated PDA patients and those with congenital cardiac deformities.

Results

Evaluating the patients' pulmonary artery pressure (PAP), pulmonary hypertension was detected in 121 patients (96.0%). Preoperative PAP was significantly higher in PDA patients with congenital heart disease compared to the isolated PDA group (p<0.05). PAP decreased significantly in postoperative follow-up in both groups (p<0.05). However, this decrease was faster in the isolated PDA group than in patients with congenital heart disease and right-left shunt accompanying PDA (p<0.05). Regarding the correlation between ductus diameters and preoperative PAP, we found that as ductus diameter increased, PAP increased significantly (p<0.05).

Conclusions

In PDA patients, closing the ductus is necessary to prevent pulmonary and cardiac complications. Surgical closure remains one of the most effective methods for this, although there is little difference between surgical treatment methods in terms of mortality.

Intravenous paracetamol for neonates: long-term diseases not escalated during 5 years of follow-up

OBJECTIVE

To evaluate the long-term adverse reactions of paracetamol in children who required intensive care shortly after birth. Paracetamol is a widely used analgesic in neonates, but the long-term studies are lacking. Previous epidemiological studies have reported associations between early paracetamol intake and diseases in childhood.

DESIGN

Five-year follow-up cohort of children who required intensive care shortly after birth.

SETTING

Single tertiary care hospital; neonatal and paediatric intensive care units.

INTERVENTIONS

Intravenous paracetamol was administered for pain and discomfort to the neonates during their intensive care, while for the control infants, it was not available.

MAIN OUTCOME MEASURES

The primary outcome was the incidence of asthma; secondary outcomes were neonatal diseases and long-term morbidities (atopic dermatitis, inflammatory bowel disease, autism, speech disorders, cerebral palsy). Long-term morbidities were adjusted based on antenatal and neonatal risk factors.

RESULTS

We screened all neonates admitted to the intensive care units soon after birth in Oulu University Hospital, Oulu, Finland, during 1 October 2007 to 31 December 2013. Altogether, 1552 infants needed intensive care. Of them, 735 (47%) were treated with intravenous paracetamol. We obtained their long-term data from the Finnish National Institute for Health and Welfare, including all physician-made diagnoses from all primary healthcare units and hospitals in Finland. We found no difference in the asthma incidence or in other long-term morbidities between paracetamol-treated and non-exposed infants.

CONCLUSIONS

Intravenous paracetamol given to neonates did not associate with childhood disorders compared with the non-exposed infants during the 5-year follow-up. The previous hypothesis that early paracetamol use causes childhood morbidities was not confirmed.

Study protocol: baby-OSCAR trial: Outcome after Selective early treatment for Closure of patent ductus ARteriosus in preterm babies, a multicentre, masked, randomised placebo-controlled parallel group trial

BACKGROUND

The question of whether to treat patent ductus arteriosus (PDA) early or wait until symptoms appear remains high on the research agenda for neonatal medicine. Around 7000 extremely preterm babies under 29 weeks' gestation are born in the UK every year. In 40% of cases the PDA will fail to close spontaneously, even by 4 months of age. Untreated PDA can be associated with several serious and life-threatening short and long-term complications. Reliable data to support clinical decisions about PDA treatment are needed to prevent serious complications in high risk babies, while minimising undue exposure of infants. With the availability of routine bedside echocardiography, babies with a large PDA can be diagnosed before they become symptomatic.

METHODS

This is a multicentre, masked, randomised, placebo-controlled parallel group trial to determine if early-targeted treatment of a large PDA with parenteral ibuprofen in extremely preterm babies (23+ 0-28+ 6 weeks' gestation) improves short and long-term health and economic outcomes. With parental informed consent, extremely preterm babies (born between 23+ 0-28+ 6 weeks' gestation) admitted to tertiary neonatal units are screened using echocardiography. Babies with a large PDA on echocardiography, defined by diameter of at least 1.5 mm and unrestricted pulsatile PDA flow pattern, are randomly allocated to either ibuprofen or placebo within 72 h of birth. The primary endpoint is the composite outcome of death by 36 weeks' postmenstrual age or moderate or severe bronchopulmonary dysplasia (BPD) at 36 weeks postmenstrual age.

DISCUSSION

Prophylactic pharmacological treatment of all preterm babies unnecessarily exposes them to potentially serious side effects of drug treatment, when their PDA may have closed spontaneously. However, delaying treatment until babies become symptomatic could result in loss of treatment benefit as irreversible damage may have already been done. Targeted, early pharmacological treatment of PDA in asymptomatic babies has the potential to overcome the disadvantages of both prophylactic (overtreatment) and symptomatic approaches (potentially too late). This could result in improvements in the clinically important short-term clinical (mortality and moderate or severe BPD at 36 weeks' postmenstrual age) and long-term health outcomes (moderate or severe neurodevelopment disability and respiratory morbidity) measured at 2 years corrected age.

TRIAL REGISTRATION

ISRCTN84264977 . Date assigned: 15/09/2010.

Oral Paracetamol vs Oral Ibuprofen in Patent Ductus Arteriosus: A Randomized, Controlled, Noninferiority Trial

OBJECTIVE

To test the hypothesis that oral paracetamol is non-inferior to oral ibuprofen in closing hemodynamically significant patent ductus arteriosus (hsPDA) with an a priori noninferiority (NI) margin of 15%.

STUDY DESIGN

Multicenter, randomized, controlled, NI trial conducted in level III neonatal intensive care units. Consecutively inborn preterm neonates of <32 weeks of gestation with hsPDA were included. Those with structural heart disease, major malformations, and contraindications for enteral feeding or for administration of study drugs were excluded. Interventions included oral paracetamol in the experimental arm and oral ibuprofen in the active control arm. The primary outcome was closure of hsPDA by 24 hours from the last dose of the study drug. Secondary outcome measures included closure of hsPDA by 24 hours after the first course of the study drug, rate of reopening after the first course, and adverse events associated with the study drug.

RESULTS

Out of 1250 neonates screened, 161 were randomized. Oral paracetamol was noninferior to oral ibuprofen in closure of hsPDA by both per protocol analysis (62 [95.4%] vs 63 [94%]; relative risk [RR], 1.01 [95% CI, 0.94-1.1]; risk difference [RD], 1.4 [95% CI, -6 to 9]; P = .37) and intention-to-treat analysis (63 [89%] vs 65 [89%]; RR, 0.99 [95% CI, 0.89-1.12]; RD, -0.3 [95% CI, -11 to 10]; P = .47). All adverse events were comparable in the 2 study arms.

CONCLUSIONS

Oral paracetamol is noninferior to oral ibuprofen for the closure of hsPDA in preterm neonates of <32 weeks of gestation. No difference was observed in the adverse events studied.

Neonatal functional echocardiography

PURPOSE OF REVIEW

The role of echocardiography has dramatically changed over the past decade and use of functional echocardiography has become increasingly popular among neonatologists and pediatric intensivists in making clinical decisions in sick infants and children. The purpose of this review is to outline the current capabilities and limitations of functional echocardiography, best practices for its clinical application, and evidence for its utility.

RECENT FINDINGS

Functional echocardiography can provide direct assessment of hemodynamics at bedside and can be used as a modern hemodynamic monitoring tool in the neonatal intensive care unit. It is now being regarded as a useful extension to the clinical examination and other monitoring tools in the critically ill infant. The anatomic, physiological, and hemodynamic information functional echocardiography provides can be used in targeting specific interventions and evaluating response to treatment.

SUMMARY

This review article is focused on an overview of the most common applications of functional neonatal echocardiography also called targeted neonatal echocardiography or neonatologist performed echocardiography. It will review assessment of hemodynamics and cardiac function in neonatal hypotension and shock, suspected patent ductus arteriosus, suspected persistent pulmonary hypertension of the newborn with evaluation of pulmonary artery pressure and assessment of pericardial effusion. It will also emphasize the specific requirements for the practice and training of functional neonatal echocardiography.

Ductus arteriosus and failed medical therapy

BACKGROUND

Management of a patent ductus arteriosus (PDA) after pharmacological therapy failure in preterm neonates is controversial and shows marked practice variation. To evaluate which factors motivate the decision to ligate a PDA in clinical practice we examined several clinical and echocardiographic variables.

METHODS

We conducted a retrospective single center cohort study. We included infants born at less than 37 weeks of gestation, admitted to our neonatal intensive care between 01.01.2008 and 31.12.2015 with a PDA detected on echocardiography after two or three courses of medical therapy. Logistic regression analyses were used to predict surgical ligation for twelve clinical and nine echocardiographic variables separately. We used the multiple imputation technique for missing values.

RESULTS

A total of 89 neonates were included of which forty (45%), underwent surgical ligation of their PDA. In our final multivariate regression model, invasive respiratory support (OR 3.6, 95% CI 1.29-10.03), left atrial/aortic root ratio (OR 5.48, 95% CI 1.66-18.11) and presence of ductal steal (OR 3.82, 95% CI 1.47-9.91) were significant predictors for surgical ligation. The prediction model using clinical and echocardiographic variables explained 9% and 24% of the variability to ligate respectively, indicating significant residual variation due to unmeasured factors.

CONCLUSIONS

Our results indicate that invasive respiratory support, increased left atrial/aortic root ratio and the presence of ductal steal were important predictors for surgical ligation in our center. However, this explained only a small proportion of the variability, which emphasizes the need for evidence-based guidelines in the management of preterm neonates after failed pharmacological therapy for a PDA.

Comparison of 'post-patent ductus arteriosus ligation syndrome' in premature infants after surgical ligation vs. percutaneous closure

OBJECTIVE

To compare the incidence of post-PDA ligation syndrome after surgical vs. percutaneous closure of PDAs in very low birth weight (VLBW) infants.

STUDY DESIGN

Cohort study comparing 59 infants who underwent surgical ligation with 25 infants who underwent percutaneous closure. Comparisons between groups were made using two-sample t-tests and a Fisher's exact test. Comparisons of pre vs. post variables within each group were made using paired t-tests.

RESULTS

Patients who underwent surgical ligation had a higher need for initiation of post-procedure hemodynamic support (12/59 vs. 0/24, p = 0.016), a higher post-procedure peak FiO₂ (0.64 vs. 0.43, p = 0.004), and a larger absolute change in peak FiO₂ (0.23 vs. 0.09, p = 0.008).

CONCLUSION

VLBW infants who had percutaneous closure of their PDA did not experience post ligation syndrome and had less escalation of respiratory support compared with infants who underwent surgical ligation.

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

Persistent Patent ductus arteriosus (PDA) is a common finding in extremely low gestational age newborn infants and its prevalence is inversely proportional to the gestational age. The presence of a persistent PDA is associated with increased mortality and several significant morbidities including intraventricular hemorrhage, pulmonary hemorrhage, necrotizing enterocolitis, and chronic lung disease or bronchopulmonary dysplasia. However, treating PDA has not been demonstrated to have beneficial impact on the long term outcomes. Currently there is no consensus on whether to treat the PDA or not, and if treat, when to treat and how to treat. The echocardiography is the investigation of choice to diagnose PDA, estimating the magnitude of shunt volume and assessing its hemodynamic significance, and to exclude/diagnose any associated congenital heart defect before any intervention. Various echocardiographic parameters and staging/scoring systems have been described to help the clincians making the clinical decisions and some of theses scoring systems are quite complex to apply in a busy day to day clinical practice. This concised review paper is focused to help the clinicians in making a clinical decision based upon clincial and echocardiography parameters. Hence, only the parameters which are commonly used and helpful in making the clinical decisions in day to day clincial practice have been described in this paper.

Selective Treatment of PDA in High-Risk VLBW Infants With Birth Weight ≤800 g or <27 Weeks and Short-Term Outcome: A Cohort Study

Background: Patent ductus arteriosus (PDA) causing significant left to right shunt can increase key morbidities in preterm infants. Yet, treatment does not improve outcomes and spontaneous closure is the natural course of PDA. The Impact of PDA on 23-26-week gestation infants is uncertain. Selective treatment of such infants would likely balance outcomes. Objective: To test the hypothesis that treatment of PDA in high-risk VLBW infants [birth weight ≤800 g or gestation <27 weeks, hemodynamically significant, ductal diameter (DD, ≥1.6 mm), and mechanical ventilation] and expectant management in low-risk infants will reduce the need for treatment and surgical ligation, without altering short term morbidities. Methods: This prospective observational study was initiated subsequent to the introduction of a new treatment protocol in 2016. The 12-months before and after protocol introduction were, respectively, defined as standard and early selective treatment periods. In the early selective treatment cohort, PDA was treated with indomethacin, maximum of two courses, 1 week apart. Surgical ligation was considered after 30 days of age if indicated (DD ≥2 mm, mechanical ventilation). Primary outcomes were need for treatment and rate of ligation. Protocol compliance and secondary outcomes were documented. Results: 415 infants were studied, 202 and 213 in the standard treatment and early selective treatment cohorts, respectively. Numbers treated (per protocol) in the standard treatment and early selective treatment cohorts were 27.7 and 19.3% (56/202 and 41/213) (p = 0.049), and the respective ligation rates were 7.54 and 2.96% (P = 0.045). Secondary outcomes were comparable. Conclusion: The early selective treatment protocol reduced the rates of treatment and surgical ligation of PDA, without altering key morbidities. Further studies under a randomized control trial setting is warranted.

Effects of Patent Ductus Arteriosus on Organ Blood Flow in Infants Born Very Preterm: A Prospective Study with Serial Echocardiography

OBJECTIVE

To characterize the effects of a patent ductus arteriosus (PDA) on different organ blood flows in infants born preterm.

STUDY DESIGN

Infants born preterm at ≤30 weeks of gestational age had daily echocardiography and Doppler assessments of middle cerebral artery, celiac artery, superior mesenteric (SMA), and renal arteries (RA) during the first postnatal week. Abnormal organ blood flow was defined as either reverse or absent diastolic flow, abnormally low mean or systolic velocities, or abnormally high pulsatility or resistance index.

RESULTS

Twenty-five infants born very preterm (gestational age 27.0 ± 2.1 weeks) were enrolled. PDA presence at time of measurement increased the risk of abnormal organ blood flows (39% vs 8%, P < .001). Ductal diameter and left atrium-to-aortic root (LA/Ao) ratio correlated positively with resistance index (celiac artery, SMA, RA), and negatively with mean velocity (ductal diameter: SMA, RA; LA/Ao ratio: RA). A PDA >2.0 mm, LA/Ao ratio >1.4, and their combination were associated with 8.0 (95% CI 1.6-39.4)-, 6.7 (1.3-34.7)-, and 38.2 (3.2-455.5)-fold increase in risk of abnormal organ blood flow index, respectively. Abnormal descending aorta flow was detected in only 2% of measurements.

CONCLUSIONS

Ductal size >2.0 mm and LA/Ao >1.4, especially in combination, are associated with a greater risk of abnormal organ blood flows. We suggest that Doppler assessment of the renal and superior mesenteric arteries are more likely to detect systemic hypoperfusion than the descending aorta.

Late manifestation coarctation of the aorta in a premature infant 4-month post-percutaneous device closure of a patent ductus arteriosus

Patent ductus arteriosus is the most common cardiovascular abnormality in premature infants. With newly available percutaneous devices, centres are reporting high rates of success and favourable safety profiles with percutaneous closure of haemodynamically significant ductus arteriosi in infants under 1000 g. We report the case of a 5-week-old, previous 25-week gestation, 1200-g infant who underwent successful percutaneous closure of a ductus arteriosus with a Medtronic Microvascular Plug but who developed late-term coarctation from the device. This case should prompt practitioners to consider the need and timing of follow-up echocardiograms in this population and sheds light on a newly reported long-term complication of device closure in premature infants.

Patent ductus arteriosus ligation on neurodevelopmental outcomes at corrected 2 years

Background

Our aim in this study was to evaluate whether very low birth weight infants (VLBWI) ligated for patent ductus arteriosus (PDA) were associated with worse neurodevelopmental outcomes at corrected 2 years. The ligated group was subdivided into ≤2 weeks of life (early) and ligated > 2 weeks of life (late) groups and compared the in-hospital morbidities and long term outcomes.

Methods

Between Dec 2013 and Dec 2015, VLBWI diagnosed with hs PDA were evaluated.

Results

Of the 191 VLBW infants with hs PDA, 28 (14.7%) infants had surgical ligation for PDA; 11 (39%) infants had EL and 17 (61%) infants had LL. Surgical ligation of hs PDA group had higher morbidities and mortality. Among the142 (83.0%) infants of 171 VLBWI with PDA survived, infants who were ligated had significantly lower scores of Bayley Scales of Infant and Toddler Development III at corrected age of 18 months. However, among the ligated group, there was little evidence of differences between the EL and LL groups. In a multivariable logistic regression analysis, only longer exposure of hs PDA and mechanical ventilation were consistently associated with worse neurodevelopmental outcomes.

Conclusion

Our results suggest that surgical ligation for hs PDA may not increase risk for poor neurodevelopmental outcomes at corrected 2 years of age. The early surgical ligation may not be a risk factor.

Cerebral perfusion and assessing hemodynamic significance for patent ductus arteriosus using near infrared red spectroscopy in very low birth weight infants

INTRODUCTION/OBJECTIVE

To study the impact of hemodynamically significant patent ductus arteriosus (hsPDA), using near infrared red spectroscopy (NIRS) regional cerebral (SrO₂), renal (RrO₂) saturation measurements, and fractional tissue oxygenation extraction (FTOE) before and after medical and/or surgical treatment.

METHODS

Prospective cohort study of very low birth weight (VLBW) preterm infants with hsPDA requiring treatment from March 2014 to December 2016 in a tertiary Neonatal Intensive Care Unit in Singapore. NIRS was applied at diagnosis until 24-48 h after the last dose of ibuprofen or postsurgical ligation. All PDAs were documented to be closed by echocardiography. Post-treatment values (control group) were compared against pretreatment values.

RESULTS

Twenty-nine infants were studied, with mean gestational age of 26.7 weeks and birth weight of 956 g. Median day of life of PDA diagnosis was 4. Seven infants (24.1%) underwent PDA ligation. There was significant reduction in FTOE before treatment till after last dose of medication or ligation by a mean difference of 7.27% (p < .05). Reduction in FTOE was also found between the first dose of medication till after the last dose or ligation. Cerebral SrO₂ significantly increased between first dose of medication till last dose of medication by a mean difference of 3.09% (p = .034). RrSO2 values were not significantly affected. No correlation between NIRS values and PDA size was found.

CONCLUSIONS

Significant increase in cerebral SrO₂ and reduction in FTOE by NIRS post PDA closure in hemodynamically significant PDAs suggest that PDA closure may reduce cerebral hypoxia burden.

Platelet Transfusion for PDA Closure in Preterm Infants: A Randomized Controlled Trial

BACKGROUND AND OBJECTIVES

Thrombocytopenia is associated with late closure of patent ductus arteriosus (PDA). There are few studies evaluating platelet transfusions to treat PDA. We compared liberal platelet-transfusion criteria (to maintain a platelet count >100 000 per µL) versus standard criteria achieve earlier PDA closure among thrombocytopenic preterm neonates (<35 weeks' gestation) with hemodynamically significant PDA (hs-PDA) presenting within the first 2 weeks of life.

METHODS

Thrombocytopenic (<100 000 per µL) preterm neonates with hs-PDA were enrolled and randomly allocated to the liberal and standard transfusion groups: 22 in each arm. They underwent echocardiography daily until closure of PDA, completion of 120 hours follow-up, or death. All subjects received standard cotreatment with nonsteroidal antiinflammatory drugs. Primary outcome of time to PDA closure was compared by survival analysis. Multivariate Cox proportional hazard regression was performed with randomization group, baseline platelet count, gestational age, and age at enrollment as predictor variables.

RESULTS

Median time to PDA closure was 72 (95% confidence interval [CI] 55.9-88.1) versus 72 (95% CI 45.5-98.4) hours in the liberal versus restrictive transfusion groups, respectively (unadjusted hazard ratio 0.88 [95% CI 0.4-1.9]; P = .697). Despite adjusting for potential confounders, there was no significant difference in time to PDA closure. In the liberal transfusion group, 41% of infants had any grade of intraventricular hemorrhage compared with 4.5% in the restrictive group (P = .009).

CONCLUSIONS

Attempting to maintain a platelet count >100 000 per µL by liberally transfusing platelets in preterm thrombocytopenic neonates with hs-PDA does not hasten PDA closure.

Predictors of Respiratory Improvement 1 Week after Ligation of Patent Ductus Arteriosus in Preterm Infants

OBJECTIVE

To characterize preterm infants that demonstrates respiratory improvement 7 days after ligation of a patent ductus arteriosus (PDA).

STUDY DESIGN

We performed a 2-phase study of preterm infants (birthweight <1500 g between 2010 and 2016). We first did a retrospective analysis using regression modeling of ligation population. We then performed a case-control study comparing a ligation group with infants matched by gestational age, postnatal age, and preligation respiratory condition (ventilator mode, mean airway pressure [MAP], and fraction of inspired oxygen [FiO₂]). Respiratory improvement was defined as either extubation, downgrading of ventilatory mode, reduction in MAP >25%, or decrease in FiO₂ >25%.

RESULTS

Forty-five (42%) of 107 preterm infants (gestational age 25.5 ± 1.7 weeks) with ligation showed respiratory improvement at 7 days. Infants on high frequency ventilation (HFV) were more likely to have respiratory improvement (aOR 5.03, 95% CI [1.14-22.18]). In matched-control analysis of 89 pairs, there was no difference in respiratory improvement. Among infants on HFV, the ligation group had an increase in MAP during 3 days prior to ligation. For infants on conventional ventilation, the ligation group had higher MAP and FiO₂ than the control group during the first 2-3 postoperative days.

CONCLUSIONS

Among infants undergoing PDA ligation, those on HFV were more likely to have respiratory improvement in the first week, possibly because of the prevention of further respiratory deterioration. For infants on conventional ventilation, ligation was associated with higher respiratory support in the immediate postligation period without respiratory benefits at 7 days. As HFV was used as a rescue mode, our findings suggest that those with worse lung disease may achieve greater short term benefit from PDA ligation.

What is a hemodynamically significant PDA in preterm infants?

OBJECTIVE

There is no consensus on the definition of a hemodynamically significant patent ductus arteriosus (hsPDA). In this review article, our objective is to discuss the main variables that one should consider when determining the hemodynamic significance of a PDA.

RESULTS

We describe the various approaches that have been utilized over time to define an hsPDA and discuss the strengths and weaknesses of each echocardiographic index. Finally, we propose a comprehensive and individualized approach in determining the hemodynamic significance of the PDA.

CONCLUSION

There are several PDA-related clinical, echocardiographic, and other objective variables to take into consideration when defining an hsPDA. However, vulnerability based on gestational or chronological age is an important contributor as well.

Photoplethysmographic assessment of pulse transit time correlates with echocardiographic measurement of stroke volume in preterm infants with patent ductus arteriosus

OBJECTIVE

We aimed to correlate photoplethysmographic parameters with stroke volume in infants with PDA. Photoplethysmography constitutes the optical signal in pulse oximetry.

STUDY DESIGN

Stroke volume was determined echocardiographically. Pulse transit time, right hand to foot arrival time difference, and relative amplitude were measured from pulse oximeter and ECG waveforms. Photoplethysmographic parameters before and after PDA closure were compared with stroke volume.

RESULTS

After PDA closure, pulse transit time to the hand and to the foot were prolonged (54.7 ± 6.7 vs 65.5 ± 9.8 ms, p < 0.001, 82.5 ± 12.8 vs 88.6 ± 10.6 ms, p = 0.03), arrival time difference decreased (27.7 ± 7.6 vs 23.1 ± 5.6 ms, p = 0.021), and relative amplitude decreased (from 2.1 ± 0.7% to 1.5 ± 0.5%, p = 0.003). The time-based photoplethysmographic parameters correlated with stroke volume.

CONCLUSIONS

Photoplethysmographic waveform parameters are significantly different before and after PDA closure and the time-based parameters correlate well with stroke volume. Monitoring pulse transit time may assist in evaluation for spontaneous PDA closure or response to therapy.

Monitoring cerebral oxygenation of the immature brain: a neuroprotective strategy?

Monitoring of cerebral oxygenation (rScO₂) with near-infrared spectroscopy (NIRS) is a feasible noninvasive bedside technique in the NICU. This review discusses the possible neuroprotective role of "pattern recognition" of NIRS-derived rScO₂ in preterm neonates with regard to the prevention of severe intraventricular hemorrhage and hypoxia/hyperoxia-related white matter injury. This neuroprotective role of rScO₂ monitoring is discussed as a modality to aid in the early detection of cerebral oxygenation conditions predisposing to these complications. Practical guidelines are provided concerning management of abnormal rScO₂ patterns as well as a brief discussion concerning the need for international consensus and the legal aspects associated with the introduction of a new NICU bedside monitoring strategy.

Intravenous paracetamol was associated with closure of the ductus arteriosus in extremely premature infants

AIM

Symptomatic patent ductus arteriosus may lead to serious complications in extremely preterm and extremely low birthweight infants and is often resistant to medication. We evaluated early intravenous paracetamol for pain prevention during respiratory therapy, in an attempt to understand the ductal treatment of such infants.

METHODS

Our cohort were 295 extremely preterm or extremely low birthweight infants, born at less than 28 weeks or 1000 g, respectively, who were treated in the neonatal intensive care unit of Oulu University Hospital from 2002 to 2015, before and after intravenous paracetamol was introduced in June 2009. Ductal closure dates, paracetamol medication details, morbidities and mortality data were evaluated.

RESULTS

Intravenous paracetamol was given to 128 infants, starting at a median of 4.4 hours age (range: 0-169 hours), with a mean total dosage of 212 mg/kg (range: 7.5-1175 mg/kg). We also included 167 controls who were mainly treated before we used intravenous paracetamol. Ibuprofen (p < 0.001) and ligation (p = 0.002) were lower in the paracetamol group than controls. No adverse effects were detected. Paracetamol was not associated with other morbidities.

CONCLUSION

We found that early use of intravenous paracetamol decreased the incidence of ductal therapies in extremely premature or extremely low birthweight infants.

Surgical Ligation Versus Percutaneous Closure of Patent Ductus Arteriosus in Very Low-Weight Preterm Infants: Which are the Real Benefits of the Percutaneous Approach?

Percutaneous treatment of patent ductus arteriosus (PDA) in extreme premature infants is technically difficult, and therefore, often not consider as an alternative to surgery. The main objective of our work was to compare respiratory status prior and post ductal closure and morbi-mortality, in our series of preterm infants with percutaneous PDA closure versus surgical ligation in the same time-period. Retrospective review of all premature infants submitted to percutaneous and surgical PDA closure from January 2011 to December 2016. All the antenatal, perinatal, and postnatal characteristics were collected. The main outcome was the assessment of the pulmonary status before and after ductal closure using a pulmonary score. Secondary outcomes included moderate-severe disability in neurodevelopment, death before discharge, moderate-severe chronic lung disease, and morbidity at discharge. 25 patients with a mean weight of 1330 g (± 280) underwent percutaneous closure of PDA with ADO-II-AS, and a total of 53 underwent surgical ligation. 28/53 with similar gestational age, birth weight, and procedure weight to those in the percutaneous group, were selected to perform the comparative study. Ductal closure (percutaneous and surgical) resulted in improved respiratory status. However, percutaneous group achieved a fastest respiratory improvement, than surgical group. The surgical closure group associated higher morbidity among survivors (HIV, number of sepsis, need, and duration of inotropics post-interventionism). The incidence of recurrent laryngeal nerve palsy among the surgical group was 17%. Percutaneous closure of PDA in carefully selected low-weight preterm infants is a safe and reliable alternative to surgical ligation.

Does ibuprofen treatment in patent ductus arteriosus alter oxygen free radicals in premature infants?

Introduction Ibuprofen is used widely to close patent ductus arteriosus in preterm infants. The anti-inflammatory activity of ibuprofen may also be partly due to its ability to scavenge reactive oxygen species and reactive nitrogen species. We evaluated the interaction between oxidative status and the medical treatment of patent ductus arteriosus with two forms of ibuprofen. Materials and methods This study enrolled newborns of gestational age ⩽32 weeks, birth weight ⩽1500 g, and postnatal age 48-96 hours, who received either intravenous or oral ibuprofen to treat patent ductus arteriosus. Venous blood was sampled before ibuprofen treatment from each patient to determine antioxidant and oxidant concentrations. Secondary samples were collected 24 hours after the end of the treatment. Total oxidant status and total antioxidant capacity were measured using Erel's method.

RESULTS

This prospective randomised study enrolled 102 preterm infants with patent ductus arteriosus. The patent ductus arteriosus closure rate was significantly higher in the oral ibuprofen group (84.6 versus 62%) after the first course of treatment (p=0.011). No significant difference was found between the pre- and post-treatment total oxidant status and total antioxidant capacity in the groups. Discussion Ibuprofen treatment does not change the total oxidant status or total antioxidant capacity. We believe that the effect of ibuprofen treatment in inducing ischaemia overcomes the scavenging effect of ibuprofen.

Timing of surgical ligation and morbidities in very low birth weight infants

The present study examined whether early patent ductus arteriosus (PDA) surgical ligation at ≤2 weeks of life was associated with increased morbidities and mortality in very low birth weight infants (VLBWIs) who were diagnosed with hemodynamically significant (hs) PDA. Between December 2013 and December 2015, a total of 407 VLBWIs were admitted, of whom 145 (35.6%) infants were diagnosed with an hs PDA. The clinical data for these infants were retrospectively collected for analysis. Among the 145 VLBWIs with an hs PDA, 58 (40%) infants had surgical ligation for PDA; of these, 29 (50%) infants had early ligation (EL; ligation at ≤2 weeks of life) and 29 (50%) infants had late ligation (LL; ligation at ≥2 weeks of life). The mean gestational age and birth weight were significantly lower in the PDA-ligated group compared with the nonligated group. In addition, pulmonary hypertension at ≤1 week of life and neonatal seizures were significantly more prevalent in the ligated group (P < 0.05). Increased rate of ROP laser treatment, bronchopulmonary dysplasia, longer hospital stays, and longer duration of mechanical ventilation were found in ligated group (P < 0.05). However, the morbidities and mortality did not differ significantly between the EL and LL groups. Pulmonary hypertension at ≤1 week of life was significantly associated with LL (P = 0.019), which was consistently a risk factor for hs PDA ligation in our multivariable logistic regression analysis. EL was not significantly associated with increased hospital morbidities and mortality in VLBWIs with hs PDA. Pulmonary hypertension at ≤1 week of life can be a risk factor for the need for surgical ligation of hs PDA.

Efficacy and safety of rectal ibuprofen for patent ductus arteriosus closure in very low birth weight preterm infants

BACKGROUND

To compare rectal ibuprofen with oral ibuprofen for the closure of hemodynamically significant patent ductus arteriosus (hsPDA) in very low birth weight (VLBW) preterm infants.

STUDY DESIGN AND SUBJECTS

In a prospective, randomized study, 72 VLBW infants who had hsPDA received either rectal or oral ibuprofen. The plasma concentration of ibuprofen and renal functions were determined in both groups by the high-performance liquid chromatography (HPLC) method and cystatin-C (cys-C), respectively.

RESULTS

The hsPDA closure rate of the group that received rectal ibuprofen was similar to oral ibuprofen (86.1% versus 83.3%) after the first course of the treatment (p = 0.745). A statistically significant difference was identified between the mean plasma cys-C levels before and after treatment in both the rectal and oral ibuprofen groups (p = 0.004 and p< 0.001, respectively). The mean plasma ibuprofen concentration was similar in both groups after the first dose (rectal 44.06 ± 12.4; oral, 48.28 ± 22.8) and the third dose (rectal, 45.34 ± 24.3; oral, 48.94 ± 24.8) (p > 0.05 for all values).

CONCLUSIONS

Rectal ibuprofen is as effective as oral ibuprofen for hsPDA closure in VLBW infants. The rise in the cys-C level with rectal and oral treatment shows that patients with borderline renal function should be evaluated and followed closely.

Oral paracetamol versus oral ibuprofen for closure of haemodynamically significant patent ductus arteriosus in preterm neonates (<32 weeks): a blinded, randomised, active-controlled, non-inferiority trial

INTRODUCTION

Haemodynamically significant patent ductus arteriosus (hsPDA) is a common cause of mortality and morbidity in preterm infants. Existing medical therapies with ibuprofen or indomethacin have multiple adverse effects. Hence, an alternative drug like paracetamol given through oral route with less side effects need to be tested in an appropriate study design with least risk of bias to arrive at a conclusion.

METHODS AND ANALYSIS

Multisite, randomised, active-controlled, non-inferiority design. The primary objective is to study the efficacy of oral paracetamol for closure of hsPDA in comparison to oral ibuprofen in preterm neonates of <32 weeks' gestation. Randomisation web-based and allocation concealment would be done; the treating team, investigators, outcome assessors and laboratory personnel would be blinded from the intervention. Echocardiography images would be coded for independent review. Closure of PDA by the end of last dose of study drug or earlier would be the study endpoint. A sample size of 196 neonates would be enrolled with a non-inferiority margin of 15%. Both intention-to-treat and per-protocol analysis will be done to assess the effect of contamination and protocol violations in the primary outcome.

ETHICS AND DISSEMINATION

The trial would follow international code of ethics for clinical trial. The trial protocol was approved by the Institute Ethics Committee of all three centres. All serious adverse events would be reported in detail to the Institute Ethics Committee. A written informed consent would be obtained from one of the parents. No plan has been made for dissemination.

TRIAL REGISTRATION NUMBER

CTRI/2014/08/004805.

Persistent Ductus Arteriosus in Critically Ill Preterm Infants

Introduction

Persistent ductus arteriosus (PDA) is found with increased incidence in preterm infants, significantly affecting neonatal morbidity and mortality rates.

Aim

To evaluate the association between the presence of PDA and the severity of clinical condition at birth in critically ill preterm infants, with gestational ages (GA) ≤ 32 weeks and severe respiratory distress.

Methods

All preterm infants with GA ≤ 32 weeks admitted to the neonatal intensive care unit (NICU) of the Clinical County Emergency Hospital, Sibiu between 1 January 2010 and 31 December 2015 were included in the study. These were categorized as Group 1 [Preterm infants with PDA; n=154] and Group 2 [Preterm infants without PDA; n=186]. Epidemiological and clinical data were collected in the National Registry for Respiratory Distress Syndrome for all children, and data related to prenatal period, clinical characteristics at birth i.e GA, weight, gender, Apgar scores, and clinical features such as resuscitation at birth, surfactant administration, need and duration of respiratory support, neonatal sepsis, complications associated with prematurity, and death, were analyzed.

Results

Group 1 infants had significantly lower GA and birth weights, were more often out born (p=0.049, HR 1.69), and had significantly lower Apgar scores at 1 and 10 minutes (p=0.022, p=0.000). They presented a significantly higher need for surfactant administration (42.9% vs 24.7%, p<0.0001) and respiratory support (96.8% vs 90.3%, HR 3.19, p=0.019 for need of CPAP and 22.1% vs 10.8%, HR 2.35, p=0.004 for mechanical ventilation). Duration of respiratory support was also significantly higher in the Group 1 (7.6%±7.5 vs. 5.1±3.8 days, p<0.0001 for CPAP and 20.1±22.5 vs. 12.0±15.7 days, p<0.0001 for mechanical ventilation).

Conclusion

In very preterm infants, PDA may be associated with a critical clinical condition leading to serious complications. The presence of PDA after the seventh day of life was associated with an increased need for respiratory support, both CPAP and mechanical ventilation, increased severity of the respiratory distress syndrome, requiring a longer duration of respiratory support, and increased the hospitalization length. In very preterm infants, PDA presence was also associated with a higher rate of severe complications and death, indicating the need for a careful and proper management of these critical cases in neonatal intensive care units.

Modeling of neonatal hemodynamics during PDA closure

The transition of the fetus at birth to extrauterine life is an extremely complex process. As part of the hemodynamic transition, the closure of ductus arteriosus, a fetal shunt, is among the key steps to achieve normal postnatal cardiovascular function. However, significant gaps remain in our knowledge pertaining to the hemodynamics of normal ductal closure, and in case of failure of closure, to the hemodynamic consequences and treatment of the patent ductus arteriosus (PDA) in preterm infants. This paper presents a mathematical model of a newborn's cardiovascular system with five peripheral organ systems, the ductus arteriosus, and the baroreceptor reflex. We present the hemodynamic findings during simulation of sudden ductal closure, an event seen in real life when the PDA is closed surgically. The results of our model match the clinical data.

Surgical ligation of patent ductus arteriosus in premature infants: trends and practice variation

OBJECTIVE

We sought to analyse the variation in the incidence of patent ductus arteriosus over three recent time points and characterise ductal ligation practices in preterm infants in the United States, adjusting for demographic and morbidity factors.

METHODS

Using the Kids' Inpatient Database from 2003, 2006, and 2009, we identified infants born at ⩽32 weeks of gestation with International Classification of Diseases, Ninth Revision diagnosis of patent ductus arteriosus and ligation code. We examined patient and hospital characteristics and identified patient and hospital variables associated with ligation.

RESULTS

Of 182,610 preterm births, 30,714 discharges included a patent ductus arteriosus diagnosis. The rate of patent ductus arteriosus diagnosis increased from 14% in 2003 to 21% in 2009 (p<0.001). A total of 4181 ligations were performed, with an overall ligation rate of 14%. Ligation rate in infants born at ⩽28 weeks of gestation was 20% overall, increasing from 18% in 2003 to 21% in 2009 (p<0.001). The ligation rate varied by state (4-28%), and ligation was associated with earlier gestational age, associated diagnoses, hospital type, teaching hospital status, and region (p<0.001).

CONCLUSION

The rates of patent ductus arteriosus diagnosis and ligation have increased in the recent years. Variation exists in the practice of patent ductus arteriosus ligation and is influenced by patient and non-patient factors.

Pharmacological Closure of Patent Ductus Arteriosus: Selecting the Agent and Route of Administration

Opinions are divided regarding the management of a persistently patent ductus arteriosus (PDA). Some of the adverse effects associated with a large hemodynamically significant duct, including prolonged ventilation, pulmonary hemorrhage, bronchopulmonary dysplasia (BPD), necrotizing enterocolitis (NEC), intraventricular hemorrhage (IVH), and mortality, indicate that active management of infants with large ductal shunts may sometimes be necessary. Indomethacin and ibuprofen are the two US FDA-approved cyclooxygenase (COX) inhibitors used for the closure of a ductus in preterm babies. Both these drugs are effective in 70-80% of extremely low birthweight infants. Treatment with COX inhibitors may be associated with renal impairment, gastrointestinal hemorrhage, NEC, and spontaneous intestinal perforation when given concurrently with steroids, as well as changes in cerebrovascular auto-regulation. Ibuprofen appears to be a better choice for PDA closure, with a better side effect profile and efficacy that equals that of indomethacin. However, long-term outcome studies of ibuprofen are lacking, and prophylactic ibuprofen is ineffective in decreasing severe IVH. The choice of one drug over the other also depends on local availability of both drugs and the intravenous or enteral preparation. The oral preparation of ibuprofen appears as effective as the intravenous preparation. The use of paracetamol to close a hemodynamically significant PDA has increased in recent years. Paracetamol also decreases prostacyclin synthesis; however, unlike COX inhibitors, it does not have a peripheral vaso-constrictive effect and can be given to infants with contraindications to non-steroidal anti-inflammatory drugs. It appears to have similar efficacy based on limited data available from randomized trials. Until more data are available on efficacy, safety, and long-term outcomes, it cannot be recommended as the first choice.

Patent Ductus Arteriosus and Brain Volume

BACKGROUND AND OBJECTIVES

A hemodynamically significant patent ductus arteriosus (PDA) can compromise perfusion and oxygenation of the preterm brain. Reports suggest that PDA is associated with increased mortality and morbidity. We hypothesize that long-standing low cerebral oxygenation due to PDA might affect brain volume at term equivalent age.

METHODS

Observational study in 140 infants investigating the relationship between near-infrared spectroscopy-monitored cerebral oxygen saturation (rSco2) and MRI-assessed regional brain volume and maturation of the posterior limb of the internal capsule at term-equivalent age in 3 groups: those whose PDA closed with indomethacin, those who needed additional surgical closure, and matched controls.

RESULTS

The surgery group had the lowest rSco2 values before closure (n = 35), 48% ± 9.7% (mean ± SD) as compared with the indomethacin (n = 35), 59% ± 10.4 (P < .001), and control groups (n = 70), 66% ± 6.9 (P < .001); the highest postnatal age before effective treatment; and the lowest volumes of most brain regions at term-equivalent age. Multiple linear regression analysis showed a significant effect of preductal closure rSco2 on cerebellar volume in this group. No differences were found in maturation of the posterior limb of the internal capsule.

CONCLUSIONS

Long-standing suboptimal cerebral oxygenation due to a PDA may negatively influence brain growth, affecting neurodevelopmental outcome.

[Usefulness of brain natriuretic propeptide in the diagnosis and management of patent ductus arteriosus]

INTRODUCTION

Patent ductus arteriosus (PDA) is a prevalent condition in preterm infants, and may be related to increased morbidity and mortality in the most immature newborns. Recent studies have examined the usefulness of brain natriuretic propeptide (proBNP) in the diagnosis of this pathology. The aim of the study was to evaluate the diagnostic efficacy of proBNP as a marker of hemodynamic overload in PDA.

PAIENTS AND METHODS

A retrospective study was conducted on preterm infants less than 32 weeks of gestation and/or weight less than 1500 grams. Echocardiogram and determination of proBNP levels were performed on all patients. Comparison was made by subgroups according to the presence of PDA and their haemodynamic characteristics.

RESULTS

Of the 60 patients enrolled, 71.7% had PDA, of which 86% had haemodynamically significant patent ductus arteriosus (HS-PDA). All of them, but one, received medical treatment with ibuprofen or acetaminophen. Surgical closure was required in 29.7% of HS-PDA. Higher values of proBNP were found in patients with HS-PDA (33338±34494.47pg/mL; p=.000) compared with patients with closed or non-haemodynamically significant ductus arteriosus. Higher values were also found in patients who required surgical closure of PDA (30596.8±14910.9; p=.004). A greater decrease inproBNP levels was found in the group of patients which duct closure after pharmacological treatment (68±24.69% vs -12.22±99.4%; p=.030). ProBNP cutoff-level for HS-PDA was calculated by ROC curve and it was 9321.5pg/mL (Specificity: 100%, Sensitivity: 94.6%).

CONCLUSIONS

ProBNP levels are related to the presence or absence of haemodynamically significant patent ductus arteriosus; and its variations with treatment response. High values are also related to the need for surgical closure of PDA.

A prospective study of maternal preference for indomethacin prophylaxis versus symptomatic treatment of a patent ductus arteriosus in preterm infants

Background

The management of a patent ductus arteriosus in preterm infants continues to be debated among neonatologists due to the absence of concrete evidence that precisely weighs the long term outcomes of active, early intervention against a conservative approach. In the majority of institutions, parents are encouraged to play an active role in the complex, decision –making processes with regard to the care of their infants. The objective of this study is to elicit maternal preferences for indomethacin prophylaxis versus treatment of a patent ductus arteriosus (PDA) in extremely low birth weight (ELBW) infants, utilizing a decision aid instrument (DAI).

Methods

Healthy and high risk pregnant women at 23–28 weeks gestation, and mothers of admitted ELBW infants were enrolled. A computer based, validated DAI was utilized during interviews. The DAI first provides information about prematurity and concurrent morbidities with comprehensive facts of the pros and cons about prophylactic versus treatment options. It subsequently coaches participants how to select values and preferences based on their decisions. A 17-item questionnaire assessed and valued each short and long term morbidity of extreme prematurity and preferred choice for PDA management.

Results

Two hundred ninety nine subjects were enrolled; 75% were healthy women at 23–28 weeks gestation, 19% were high risk and 6% recently delivered an ELBW infant. Eighty-two percent preferred a prophylactic indomethacin strategy versus symptomatic treatment for the management of PDA. Across a spectrum of potential morbidities, the occurrence of severe intraventricular hemorrhage was viewed by mothers as the most un-wanted outcome irrespective of the two proposed options.

Conclusions

In contrast to neonatal practitioners, mothers who used this particular DAI strongly endorsed prophylactic indomethacin versus a treatment intervention for the management of PDA in preterm infants.

Electronic supplementary material

The online version of this article (doi:10.1186/s12887-015-0353-4) contains supplementary material, which is available to authorized users.