Morbidity and mortality in preterm neonates with patent ductus arteriosus on day 3

Patent ductus arteriosus in preterm infants born before 30 weeks' gestation: high rate of spontaneous closure after hospital discharge

AimThe aim of this study was to determine the spontaneous closure rate of patent ductus arteriosus at a 2-year follow-up, following failed medical therapy and beyond initial hospital discharge, and to evaluate in-hospital spontaneous or pharmacological closure rates.Materials and methodsA retrospective evaluation was conducted in a cohort of preterm infants admitted to the Neonatal ICU of Ancona between January, 2004 and June, 2013. Inclusion criteria were gestational age between 24+0 and 29+6 weeks or birth weight 1.5 mm, a left atrium-to-aorta ratio >1.4, and/or reversal of end-diastolic flow in the aorta >30% of the anterograde. First-line treatment was intravenous ibuprofen. Intravenous indomethacin was used if ibuprofen failed. Surgical ligation was considered in haemodynamically significant patent ductus arteriosus after medical treatment.

RESULTS

A total of 593 infants met the inclusion criteria, and patent ductus arteriosus was diagnosed in 317 (53.4%). Among them, 283 (89.3%) infants had haemodynamically significant patent ductus arteriosus, with pharmacological closure achieved in 228 (80.6%) infants and surgical ligation performed in 20 (7.1%). Follow-up at 24 months was available for 39 (81.3%) of 48 infants with patent ductus arteriosus at the hospital discharge: 36 (92.3%) underwent spontaneous closure, two (5.1%) underwent surgical ligation, and one (2.6%) had a patent ductus arteriosus.DiscussionA significant number of patent ductus arteriosus that fail pharmacological closure undergo spontaneous closure by the age of 2 years. This information should be taken into account when considering surgery or additional attempts of pharmacological closure.

Prophylactic and early targeted treatment of patent ductus arteriosus

Treatment of a haemodynamically significant patent ductus arteriosus (PDA) in the very preterm infant has been an accepted approach for several decades. However, the rationale for closure of PDA has recently been challenged due to reports of success with conservative approaches and the lack of evidence for longer-term benefits from treatment. In this article, we address an approach to assess treatment of those babies most likely to benefit.

Late oral acetaminophen versus immediate surgical ligation in preterm infants with persistent large patent ductus arteriosus

OBJECTIVE

The study objective was to evaluate the association of oral acetaminophen therapy versus immediate surgical ligation with neonatal outcomes in infants with persistent patent ductus arteriosus.

METHODS

We performed a retrospective cohort study of preterm infants born 28⁺⁶ weeks or less gestational age with persistent large patent ductus arteriosus being considered for surgical ligation after unsuccessful medical therapy. Infants in epoch 1 (July 2009 to June 2012) were immediately referred for ligation, and infants in epoch 2 (July 2012 to June 2015) were treated with oral acetaminophen and referred for ligation in the absence of improvement. The primary outcome was a composite of death or chronic lung disease.

RESULTS

A total of 92 infants with median (interquartile range) gestational age 25.2 weeks (24.4-26.3) had persistent large patent ductus arteriosus (43 in epoch 1, 49 in epoch 2). Infants in epoch 2 had decreased surgical ligation (26 [53%] vs 31 [72%]; adjusted odds ratio [aOR], 0.32; 95% confidence interval [CI], 0.12-0.89) but increased chronic lung disease (36 [73%] vs 25 [58%]; aOR, 3.34; 95% CI, 1.05-10.58) and increased death/chronic lung disease of borderline significance (39 [80%] vs 29 [67%]; aOR, 3.09; 95% CI, 0.99-9.63). Infants in epoch 2 took longer to wean off of positive pressure ventilation (28.5 vs 24 days after enrollment; aOR, 0.52; 95% CI, 0.31-0.85).

CONCLUSIONS

Late oral acetaminophen therapy for infants with persistent patent ductus arteriosus is associated with reduced surgical ligation but increased chronic lung disease. In light of a lack of improvement in clinical outcomes, the individual contributory effects of acetaminophen, surgical ligation, and prolonged exposure to patent ductus arteriosus require further study to define the optimal approach.

Patent ductus arteriosus, its treatments, and the risks of pulmonary morbidity

A persistent left-to-right shunt through a patent ductus arteriosus (PDA) increases the rate of hydrostatic fluid filtration into the lung's interstitium, impairs pulmonary mechanics, and prolongs the need for mechanical ventilation. In preclinical trials, pharmacologic PDA closure leads to improved alveolarization and minimizes the impaired postnatal alveolar development that is the pathologic hallmark of bronchopulmonary dysplasia (BPD). Although routine prophylactic treatment of a PDA on the day of birth does not appear to offer any more protection against BPD than delaying treatment for 2-3 days, recent evidence from quality improvement trials suggests that early pharmacologic treatment decreases the incidence of BPD compared with a treatment approach that exposes infants to a moderate-to-large PDA shunt for the first 7-10 days after birth. After the first week, routine pharmacologic treatment (compared with continued PDA exposure) no longer appears to alter the course of BPD development. Evidence from epidemiologic, preclinical, and randomized controlled trials demonstrate that early ductus ligation is an independent risk factor for the development of BPD.

Cerebral oxygen saturation and peripheral perfusion in the extremely premature infant with intraventricular and/or pulmonary haemorrhage early in life

Extremely preterm infants are at higher risk of pulmonary (PH) and intraventricular (IVH) haemorrhage during the transitioning physiology due to immature cardiovascular system. Monitoring of haemodynamics can detect early abnormal circulation that may lead to these complications. We described time-frequency relationships between near infrared spectroscopy (NIRS) cerebral regional haemoglobin oxygen saturation (CrSO₂) and preductal peripheral perfusion index (PI), capillary oxygen saturation (SpO₂) and heart rate (HR) in extremely preterm infants in the first 72 h of life. Patients were sub-grouped in infants with PH and/or IVH (N _H  = 8) and healthy controls (N _C  = 11). Data were decomposed in wavelets allowing the analysis of localized variations of power. This approach allowed to quantify the percentage of time of significant cross-correlation, semblance, gain (transfer function) and coherence between signals. Ultra-low frequencies (<0.28 mHz) were analyzed as slow and prolonged periods of impaired circulation are considered more detrimental than transient fluctuations. Cross-correlation between CrSO₂ and oximetry (PI, SpO₂ and HR) as well as in-phase semblance and gain between CrSO₂ and HR were significantly lower while anti-phase semblance between CrSO₂ and HR was significantly higher in PH-IVH infants compared to controls. These differences may reflect haemodynamic instability associated with cerebrovascular autoregulation and hemorrhagic complications observed during the transitioning physiology.

Factors affecting N-terminal pro-B-type natriuretic peptide levels in preterm infants and use in determination of haemodynamic significance of patent ductus arteriosus

This study aimed to investigate factors affecting N-terminal pro-B-type natriuretic peptide (NTproBNP) in preterm infants and the ability of NTproBNP to predict haemodynamically significant patent ductus arteriosus (HsPDA). Prospective cohort study of 51 infants < 30 weeks gestation. Blood NTproBNP and heart ultrasound were performed on day of life 3, 10, 28 and 36 weeks corrected age. NTproBNP levels analysed for prediction of HsPDA. The effect of gestational age, ventilation, hypoxia, bronchopulmonary dysplasia (BPD), creatinine and haemoglobin levels on NTproBNP levels were investigated. Infants with HsPDA had higher mean (SD) day 3 NTproBNP (1840 pmol/L (1058) versus 178 pmol/L (140) p < 0.001). Receiver operator curves of day 3 NTproBNP for prediction of day 3 and day 10 HsPDA had an area under the curve of 0.98 and 0.94, respectively. A chosen day 3 NTproBNP value of ≥ 287 pmol/L for the prediction of day 3 HsPDA correctly classified 92% (sensitivity 92%, specificity 92%). NTproBNP demonstrated only modest ability to predict severe BPD. Chronological but not gestational age affected NTproBNP. Ventilation, hypoxia and haemoglobin levels did not influence NTproBNP but creatinine level was positively correlated.

CONCLUSION

Day 3 NTproBNP is a useful biomarker to predict HsPDA and may be a valuable tool in future trial design. What is Known: • NTproBNP is a cardiac hormone used to diagnose and monitor cardiac dysfunction in adults and has been shown to be higher in premature infants with haemodynamically significant ductus arteriosus (HsPDA). What is new: • NTproBNP is highly predictive of ultrasound-defined HsPDA and may be a useful tool for further triage • Early NTproBNP higher in infants who develop severe BPD and with renal impairment but not affected by gestational age, recent exposure to hypoxia or haemoglobin levels while late levels unexpectedly higher in those without BPD or HsPDA.

Recent advances in cardiac catheterization for congenital heart disease

The field of pediatric and adult congenital cardiac catheterization has evolved rapidly in recent years. This review will focus on some of the newer endovascular technological and management strategies now being applied in the pediatric interventional laboratory. Emerging imaging techniques such as three-dimensional (3D) rotational angiography, multi-modal image fusion, 3D printing, and holographic imaging have the potential to enhance our understanding of complex congenital heart lesions for diagnostic or interventional purposes. While fluoroscopy and standard angiography remain procedural cornerstones, improved equipment design has allowed for effective radiation exposure reduction strategies. Innovations in device design and implantation techniques have enabled the application of percutaneous therapies in a wider range of patients, especially those with prohibitive surgical risk. For example, there is growing experience in transcatheter duct occlusion in symptomatic low-weight or premature infants and stent implantation into the right ventricular outflow tract or arterial duct in cyanotic neonates with duct-dependent pulmonary circulations. The application of percutaneous pulmonary valve implantation has been extended to a broader patient population with dysfunctional ‘native’ right ventricular outflow tracts and has spurred the development of novel techniques and devices to solve associated anatomic challenges. Finally, hybrid strategies, combining cardiosurgical and interventional approaches, have enhanced our capabilities to provide care for those with the most complex of lesions while optimizing efficacy and safety.

Percutaneous closure of a large patent ductus arteriosus in a preterm newborn weighing 1400 g without using arterial sheath: an innovative technique

Percutaneous closure of patent ductus arteriosus is well established in infants weighing >5 kg, but data regarding outcome of preterm especially very low birth weight infants is minimal. Although surgical ligation of patent ductus arteriosus is the preferred and well-accepted modality of treatment after failure of drug therapy in preterm infants, it has also got its own demerits in such a small and fragile subset. Device closure in infants weighing <1.5 kg is rarely attempted because of high chances of complications, especially acute arterial injury due to the arterial sheath. We received a 1.4-kg ventilator-dependent infant for closure of large patent ductus arteriosus. Percutaneous closure of patent ductus arteriosus was done successfully and the infant was discharged on room air with a weight of 1.8 kg. We present here an innovative technique in which successful patent ductus arteriosus device closure was done in a 1.4-kg infant without using arterial sheath.

Divergent risk factors for cerebellar and intraventricular hemorrhage

OBJECTIVE

To identify whether intraventricular hemorrhage (IVH) and cerebellar hemorrhage (CH) have common or divergent risk factors.

STUDY DESIGN

This is a retrospective cross-sectional cohort of infants including all infants born <30 weeks from 2007 to 2016. Comprehensive perinatal and clinical factors were extracted from the medical record. Outborn infants, infants with major congenital anomaly, those transferred prior to discharge, and those with mixed or no brain injury were excluded. The remaining infants were divided into two groups: IVH only and CH only. Continuous variables were evaluated with the Wilcoxon-Mann-Whitney test, and categorical variables were evaluated with Fisher's exact test. Multinomial logistic regression was used to identify factors which predispose infants towards injury type more than another, holding other factors constant.

RESULTS

In total, 127 infants were included (CH n = 27, IVH n = 100). Compared to those with IVH, infants with CH were of lower EGA (p = 0.03), lower birth weight (p = 0.01), more often of multiple gestation (p = 0.03), more frequently born emergently (p = 0.03), had a greater number of ventilator days (p = 0.03), received postnatal steroids more often (p = 0.02), had a greater incidence of hemodynamically significant patent ductus arteriosus (PDA), and less frequently had pulmonary hemorrhage (p = 0.04). In multinomial regression analysis, three factors were identified which favored CH over IVH: multiple gestation (RR 4.70, 95% CI 1.56-14.21, p < 0.01), chorioamnionitis (RR 3.18, 95% CI 1.13-8.92, p = 0.03), and emergent delivery (RR 4.14, 95% CI 1.48-11.55, p < 0.01). Only advancing gestational favored IVH over CH (RR 0.74, 95% CI 0.65-0.85, p < 0.01).

CONCLUSIONS

IVH and CH have unique risk factors. These results highlight the need to tailor neuroimaging surveillance to specific patient risk factors.

Tissue-type plasminogen activator contributes to remodeling of the rat ductus arteriosus

AIMS

The ductus arteriosus (DA) closes after birth to adapt to the robust changes in hemodynamics, which require intimal thickening (IT) to occur. The smooth muscle cells of the DA have been reported to play important roles in IT formation. However, the roles of the endothelial cells (ECs) have not been fully investigated. We herein focused on tissue-type plasminogen activator (t-PA), which is a DA EC dominant gene, and investigated its contribution to IT formation in the DA.

METHODS AND RESULTS

ECs from the DA and aorta were isolated from fetal rats using fluorescence-activated cell sorting. RT-PCR showed that the t-PA mRNA expression level was 2.7-fold higher in DA ECs than in aortic ECs from full-term rat fetuses (gestational day 21). A strong immunoreaction for t-PA was detected in pre-term and full-term rat DA ECs. t-PA-mediated plasminogen-plasmin conversion activates gelatinase matrix metalloproteinases (MMPs). Gelatin zymography revealed that plasminogen supplementation significantly promoted activation of the elastolytic enzyme MMP-2 in rat DA ECs. In situ zymography demonstrated that marked gelatinase activity was observed at the site of disruption in the internal elastic laminae (IEL) in full-term rat DA. In a three-dimensional vascular model, EC-mediated plasminogen-plasmin conversion augmented the IEL disruption. In vivo administration of plasminogen to pre-term rat fetuses (gestational day 19), in which IT is poorly formed, promoted IEL disruption accompanied by gelatinase activation and enhanced IT formation in the DA. Additionally, experiments using five human DA tissues demonstrated that the t-PA expression level was 3.7-fold higher in the IT area than in the tunica media. t-PA protein expression and gelatinase activity were also detected in the IT area of the human DAs.

CONCLUSION

t-PA expressed in ECs may help to form IT of the DA via activation of MMP-2 and disruption of IEL.

Association between early echocardiography, therapy for patent ductus arteriosus, and outcomes in very low birth weight infants

BACKGROUND

In very low birth weight infants, persistence of a patent ductus arteriosus results in morbidity and mortality. Therapies to close the ductus are effective, but clinical outcomes may depend on the accuracy of diagnosis and the timing of administration. The objective of the present study was to characterise the association between early echocardiography, therapy for patent ductus arteriosus, and outcomes in very low birth weight infants.

METHODS

This retrospective cohort study used electronic health record data on inborn infants of gestational age ⩽28 weeks and birth weight <1500 g who were discharged after day of life 7 from 362 neonatal ICU from 1997 to 2013. The primary outcome was death between day of life 7 and discharge. Secondary outcomes included bronchopulmonary dysplasia, necrotising enterocolitis, and grade 3 or 4 intraventricular haemorrhage.

RESULTS

This study included a total of 48,551 infants with a median gestational age of 27 weeks (interquartile range 25, 28) and birth weight 870 g (706, 1050). Early echocardiography - that is, performed during days of life 2 to 6 - was performed in 15,971/48,551 (33%) infants, and patent ductus arteriosus was diagnosed in 31,712/48,551 (65%). The diagnosis was more common in infants who had undergone early echocardiography (14,549/15,971 [91%] versus 17,163/32,580 [53%], p<0.001). In multivariable analysis, early echocardiography was not associated with reduced mortality (odds ratio 0.97, 95% CI 0.89-1.05). Results were similar in the subset of infants who received therapy for patent ductus arteriosus (odds ratio 1.01, 95% CI 0.90-1.15).

CONCLUSIONS

Early echocardiography was associated with an increased diagnosis of patent ductus arteriosus, but not with decreased mortality.

Using benchmarking to identify inter-centre differences in persistent ductus arteriosus treatment: can we improve outcome?

OBJECTIVE

The aim of this study was to identify inter-centre differences in persistent ductus arteriosus treatment and their related outcomes. Materials and methods We carried out a retrospective, multicentre study including infants between 24+0 and 27+6 weeks of gestation in the period between 2010 and 2011. In all centres, echocardiography was used as the standard procedure to diagnose a patent ductus arteriosus and to document ductal closure.

RESULTS

In total, 367 preterm infants were included. All four participating neonatal ICU had a comparable number of preterm infants; however, differences were observed in the incidence of treatment (33-63%), choice and dosing of medication (ibuprofen or indomethacin), number of pharmacological courses (1-4), and the need for surgical ligation after failure of pharmacological treatment (8-52%). Despite the differences in treatment, we found no difference in short-term morbidity between the centres. Adjusted mortality showed independent risk contribution of gestational age, birth weight, ductal ligation, and perinatal centre.

CONCLUSIONS

Using benchmarking as a tool identified inter-centre differences. In these four perinatal centres, the factors that explained the differences in patent ductus arteriosus treatment are quite complex. Timing, choice of medication, and dosing are probably important determinants for successful patent ductus arteriosus closure.

Oral paracetamol versus oral ibuprofen for treatment of patent ductus arteriosus

Objective

This study was performed to investigate the safety and efficacy of oral paracetamol versus oral ibuprofen in the treatment of patent ductus arteriosus (PDA) in premature infants.

Methods

Premature infants with PDA with a gestational age of ≤32 weeks or birth weight of ≤1500 g were included in this randomized study.

Results

A total of 120 premature infants fulfilled the inclusion criteria. Of these 120 infants, 34 fulfilled the treatment criteria and 22 were finally randomized. We found no significant difference in the mortality or primary closure rates between the two groups. We also found no significant difference in the short-term neonatal outcomes.

Conclusions

Either oral paracetamol or oral ibuprofen can be used safely and effectively to treat PDA in premature infants.

Intraoperative High-Frequency Jet Ventilation Is Equivalent to Conventional Ventilation During Patent Ductus Arteriosus Ligation

Background:

Patent ductus arteriosus (PDA) treatment is typically pharmacologic, but if unsuccessful, surgical ligation is commonly performed. High-frequency jet ventilation (HFJV) is used at the University of Iowa Stead Family Children’s Hospital for extremely low birth weight infants. Historically, neonates requiring PDA ligation were temporarily transferred to conventional ventilation (CV) prior to surgery.

Objective:

The objective of this study was to determine whether conversion was necessary.

Methods:

This retrospective cohort analysis examined outcomes following PDA ligation from 2014 to 2016 at the University of Iowa’s Stead Family Children’s Hospital. Infants who were transferred to CV prior to surgery and returned to HFJV postprocedure are referred to as the CV cohort. The HFJV cohort infants remained on HFJV throughout.

Results:

We found no significant increases in morbidity or mortality with the use of intraoperative HFJV and potentially show some benefit through greater reduction in serum CO2.

Conclusions:

Mode of ventilation during PDA ligation does not affect surgical morbidity or mortality or short-term clinical outcomes. Conversion to CV from HFJV is not necessary.

Prophylactic Indomethacin Compared with Delayed Conservative Management of the Patent Ductus Arteriosus in Extremely Preterm Infants: Effects on Neonatal Outcomes

OBJECTIVE

To determine whether prophylactic indomethacin (PINDO) has more or less morbidity than delayed conservative management of the moderate-to-large patent ductus arteriosus (PDA).

STUDY DESIGN

We performed a prospective double cohort controlled study of infants delivered at ≤27^6/7 weeks gestation (n = 397). From January 2005 through April 2011, all infants were treated with PINDO (n = 247). From May 2011 through August 2016, no infant was treated with indomethacin until at least 8 postnatal days (conservative epoch, n = 150). Echocardiograms were performed on day 7 and at planned intervals until the PDA was small or closed. A single neonatologist prospectively collected all data.

RESULTS

The incidence of moderate-to-large PDA on day 7 and duration of exposure to moderate-to-large PDA were significantly less in the PINDO epoch (incidence = 10%, median = 2 days) than the conservative epoch (incidence = 67%, median = 14 days). Ligation rates were low in both epochs (PINDO = 14%, conservative = 5%). In multivariate analyses, PINDO infants had a significantly lower incidence of bronchopulmonary dysplasia (BPD) (risk ratio = 0.68, CI: 0.46-0.89) and BPD or death (risk ratio= 0.78, CI: 0.62-0.95) than conservative infants. There were no differences between the epochs in death, intraventricular hemorrhage grades 3 and 4, necrotizing enterocolitis, or retinopathy of prematurity receiving treatment. The effects of PINDO on BPD and BPD or death were no longer significant when analyses were adjusted for presence of a moderate-to-large PDA on day 7. The significant effects of PINDO were independent of whether or not a ligation was performed.

CONCLUSIONS

PINDO decreases BPD and BPD or death compared with delayed conservative PDA management. These effects are mediated by closure of the PDA.

Percutaneous Patent Ductus Arteriosus (PDA) Closure During Infancy: A Meta-analysis

CONTEXT

Patent ductus arteriosus (PDA) is a precursor to morbidity and mortality. Percutaneous (catheter-based) closure is the procedure of choice for adults and older children with a PDA, but use during infancy (<1 year) is not well characterized.

OBJECTIVE

Investigate the technical success and safety of percutaneous PDA closure during infancy.

DATA SOURCES

Scopus, Web of Science, Embase, PubMed, and Ovid (Medline) were searched through December 2015 with no language restrictions.

STUDY SELECTION

Publications needed to clearly define the intervention as percutaneous PDA closure during infancy (<1 year of age at intervention) and must have reported adverse events (AEs).

DATA EXTRACTION

The study was performed according to the Systematic Reviews and Meta-Analysis checklist and registered prospectively. The quality of the selected studies was critically examined. Data extraction and assignment of AE attributability and severity were independently performed by multiple observers. Outcomes were agreed on a priori. Data were pooled by using a random-effects model.

RESULTS

Thirty-eight studies were included; no randomized controlled trials were found. Technical success of percutaneous PDA closure was 92.2% (95% confidence interval [CI] 88.8-95.0). Overall AE and clinically significant AE incidence was 23.3% (95% CI 16.5-30.8) and 10.1% (95% CI 7.8-12.5), respectively. Significant heterogeneity and publication bias were observed.

LIMITATIONS

Limitations include lack of comparative studies, lack of standardized AE reporting strategy, and significant heterogeneity in reporting.

CONCLUSIONS

Percutaneous PDA closure during infancy is feasible and associated with few catastrophic AEs; however, the limitations constrain the interpretability and generalizability of the current findings.

Urinary Neutrophil Gelatinase-associated Lipocalin in the evaluation of Patent Ductus Arteriosus and AKI in Very Preterm Neonates: a cohort study

Background

A patent ductus arteriosus (PDA) is frequently found in very preterm neonates and is associated with increased risk of morbidity and mortality. A shunt across a PDA can result in an unfavorable distribution of the cardiac output and may in turn result in poor renal perfusion. Urinary Neutrophil Gelatinase-associated Lipocalin (U-NGAL) is a marker of renal ischemia and may add to the evaluation of PDA. Our primary aim was to investigate if U-NGAL is associated with PDA in very preterm neonates. Secondary, to investigate whether U-NGAL and PDA are associated with AKI and renal dysfunction evaluated by fractional excretion of sodium (FENa) and urine albumin in a cohort of very preterm neonates.

Methods

A cohort of 146 neonates born at a gestational age less than 32 weeks were consecutively examined with echocardiography for PDA and serum sodium, and urine albumin and sodium were measured on postnatal day 3 and U-NGAL and serum creatinine day 3 and 6. AKI was defined according to modified neonatal Acute Kidney Injury Network (AKIN) criteria. The association between U-NGAL and PDA was investigated. And secondly we investigated if PDA and U-NGAL was associated with AKI and renal dysfunction.

Results

U-NGAL was not associated with a PDA day 3 when adjusted for gestational age and gender. A PDA day 3 was not associated with AKI when adjusted for gestational age and gender; however, it was associated with urine albumin. U-NGAL was not associated with AKI, but was found to be associated with urine albumin and FENa.

Conclusions

Based on our study U-NGAL is not considered useful as a diagnostic marker to identify very preterm neonates with a PDA causing hemodynamic changes resulting in early renal morbidity. The interpretation of NGAL in preterm neonates remains to be fully elucidated.

Echocardiographic Evaluation of Patent Ductus Arteriosus in Preterm Infants

Patent ductus arteriosus (PDA) is part of the typical morbidity profile of the preterm infant, with a high incidence of 80-90% in extremely low birth weight infants born before 26 weeks of gestation. Whereas spontaneous closure of the ductus arteriosus (DA) is likely in term infants, it is less so in preterm ones. PDA is associated with increased mortality and various comorbidities including cardiac failure, need for respiratory support, bronchopulmonary dysplasia, pulmonary or intracranial hemorrhage, and necrotizing enterocolitis; however, there is no proven causality between these morbidities and the presence of DA. Thus, the indication to close PDA remains highly controversial. This paper focuses on echocardiographic evaluation of PDA in the preterm infant and particularly on the echocardiographic signs of hemodynamic significance.

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.

Hospital volume and mortality due to preterm patent ductus arteriosus

BACKGROUND

Preterm patent ductus arteriosus (PDA) requires neonatal intensive care. The relationship between hospital volume and mortality of PDA remains poorly understood.

METHODS

This was a retrospective observational study, using a national inpatient database in Japan. We identified patients who were diagnosed with PDA; exclusion criteria were as follows: (i) other cardiac complications; (ii) mild PDA treated without oral/i.v. indomethacin, surgery, or catheter intervention; (iii) age >1 year at admission; (iv) gestational age ≥32 weeks; (v) death within 3 days of admission; and (vi) transferal to other hospitals. Information was collected using the Japanese Diagnosis Procedure Combination database from July 2010 to March 2013. Hospital volume was defined as the average annual number of neonates with gestational age <32 weeks at each hospital. The outcome measure was in-hospital mortality.

RESULTS

A total of 2437 eligible patients treated at 199 hospitals were included. Low, medium, and high volume were defined as average annual number of preterm infants <34, 34-65, and >65, respectively. There were no significant differences in in-hospital mortality according to hospital volume. In-hospital mortality was identical in patients who received indomethacin alone, surgical or catheter intervention, or both after adjustment for patient background.

CONCLUSIONS

There was no significant relationship between hospital volume and in-hospital mortality due to preterm PDA. Centralization of patients with this condition may not be necessary.

Elevated Nucleated Red Blood Cells at Birth Predict Hemodynamically Significant Patent Ductus Arteriosus

We hypothesized that postnatal absolute nucleated red blood cell (aNRBC) counts would be elevated in premature infants with hemodynamically significant patent ductus arteriosus (PDA), reflecting intrauterine hypoxia. PDA severity was assessed and categorized echocardiographically. aNRBC counts were significantly correlated with ductal severity (Pearson correlation: P = .007). At the extremes, aNRBC levels were 3770 (728, 6015) hemodynamically significant PDA vs 865 (483, 2528) closed ductus.

[Factors influencing the prognosis of patent ductus arteriosus in very low birth weight infants]

OBJECTIVE

To investigate the factors influencing the prognosis of patent ductus arteriosus (PDA) in very low birth weight (VLBW) infants.

METHODS

A total of 194 VLBW infants who were admitted from January 2012 to December 2014 were enrolled as study subjects. According to cardiac ultrasound findings and treatment outcome, these infants were divided into non-PDA group, spontaneous closure group, pharmaceutical closure group, and surgical closure group. Their clinical and echocardiographic characteristics were analyzed.

RESULTS

The spontaneous closure rate of PDA was 58.7%. The spontaneous closure group showed significantly higher gestational age, birth weight, and proportion of small-for-gestational-age infants than the pharmaceutical and surgical closure groups (P<0.05). The pharmaceutical and surgical closure groups had a significantly higher incidence rate of neonatal respiratory distress syndrome and a significantly higher proportion of infants who were given pulmonary surfactant (PS) than the spontaneous closure group (P<0.05). During different periods of time, the spontaneous closure group had a significantly smaller ductus arteriosus diameter than the pharmaceutical and surgical closure groups (P<0.05). The multivariate logistic regression analysis showed that gestational age, application of PS, and ductus arteriosus diameter at 48 hours were significantly associated with the prognosis of PDA. The major transductal flow pattern in the spontaneous closure group was closing pattern, while in the pharmaceutical and surgical closure groups, the main flow patterns were pulmonary hypertension and growing patterns within 48 hours and growing pattern on days 4 and 7.

CONCLUSIONS

The VLBW infants have a high spontaneous closure rate of PDA. A decreased closure rate of PDA is associated with the lower gestational age and the application of PS. PDA with a large ductus arteriosus diameter and a growing or pulsatile flow pattern cannot easily achieve spontaneous closure.

[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.

Percutaneous Patent Ductus Arteriosus (PDA) Closure in Very Preterm Infants: Feasibility and Complications

BACKGROUND

Percutaneous closure of patent ductus arteriosus (PDA) in term neonates is established, but data regarding outcomes in infants born very preterm (<32 weeks of gestation) are minimal, and no published criteria exist establishing a minimal weight of 4 kg as a suitable cutoff. We sought to analyze outcomes of percutaneous PDA occlusion in infants born very preterm and referred for PDA closure at weights <4 kg.

METHODS AND RESULTS

Retrospective analysis (January 2005-January 2014) was done at a single pediatric center. Procedural successes and adverse events were recorded. Markers of respiratory status (need for mechanical ventilation) were determined, with comparisons made before and after catheterization. A total of 52 very preterm infants with a median procedural weight of 2.9 kg (range 1.2-3.9 kg) underwent attempted PDA closure. Twenty-five percent (13/52) of infants were <2.5 kg. Successful device placement was achieved in 46/52 (88%) of infants. An adverse event occurred in 33% of cases, with an acute arterial injury the most common complication. We observed no association between weight at time of procedure and the risk of an adverse event. No deaths were attributable to the PDA closure. Compared to precatheterization trends, percutaneous PDA closure resulted in improved respiratory status, including less exposure to mechanical ventilation (mixed effects logistic model, P<0.01).

CONCLUSIONS

Among infants born very preterm, percutaneous PDA closure at weights <4 kg is generally safe and may improve respiratory health, but risk of arterial injury is noteworthy. Randomized clinical trials are needed to assess clinically relevant differences in outcomes following percutaneous PDA closure versus alternative (surgical ligation) management strategies.

[Risk factors for patent ductus arteriosus in early preterm infants: a case-control study]

OBJECTIVE

To investigate the risk factors for the occurrence of patent ductus arteriosus (PDA) and to provide a clinical basis for reducing the occurrence of PDA in early preterm infants.

METHODS

A total of 136 early preterm infants (gestational age≤32 weeks) who were hospitalized between January 2013 and December 2014 and diagnosed with hemodynamicalhy significant PDA (hs-PDA) were enrolled as the case group. Based on the matched case-control principle, 136 early preterm infants without hs-PDA were selected among those who were hospitalized within the same period at a ratio of 1:1 and enrolled as the control group. The two groups were matched for sex and gestational age. The basic information of neonates and maternal conditions during the pregnancy and perinatal periods were collected. Logistic regression analysis was performed to identify the risk factors for the development of PDA.

RESULTS

Univariate analysis showed that neonatal infectious diseases, neonatal respiratory distress syndrome, decreased platelet count within 24 hours after birth, and low birth weight were associated with the development of hs-PDA (P<0.05). Multivariate conditional logistic regression analysis revealed that neonatal infectious diseases (OR=2.368) and decreased platelet count within 24 hours after birth (OR=0.996) were independent risk factors for hs-PDA.

CONCLUSIONS

Neonatal infectious diseases and decreased platelet count within 24 hours after birth increase the risk of hs-PDA in early preterm infants.

What is the basis for a genetic approach in neonatal disorders?

Gene-environment interactions likely account for some degree of the variance in response rates that are clinically observed with antenatal corticosteroids, breast milk prophylaxis, surfactant administration, early recognition and treatment of sepsis, utility of non-invasive ventilation, and judicious exposure to supplemental oxygen. While these therapies and practice guidelines have significantly decreased overall neonatal mortality in the NICU, they have not made a marked impact on the frequency and severity of conditions such as bronchopulmonary dysplasia (BPD), necrotizing enterocolitis, and periventricular leukomalacia. One possible explanation is that genetic factors in the neonate modulate response to external intervention or preventative agents, culminating in variable levels of injury and different degrees of resolution and repair. Gene-environment explanations are supported by the observed heritability of BPD in twin studies, but they do not differentiate the interactions between neonate and offending toxin or pathogen, from interactions between neonate and intervention or therapeutic agent. Likely, both kinds of interactions are important in determining outcome.

A Patent Ductus Arteriosus Severity Score Predicts Chronic Lung Disease or Death before Discharge

OBJECTIVES

To test the hypothesis that a patent ductus arteriosus (PDA) severity score (PDAsc) incorporating markers of pulmonary overcirculation and left ventricular (LV) diastolic function can predict chronic lung disease or death before discharge (CLD/death).

STUDY DESIGN

A multicenter prospective observational study was conducted for infants <29 weeks gestation. An echocardiogram was carried out on day 2 to measure PDA diameter and maximum flow velocity, LV output, diastolic flow in the descending aorta and celiac trunk, and variables of LV function using tissue Doppler imaging. Predictors of CLD/death were identified using logistic regression methods. A PDAsc was created and a receiver operating characteristic curve was constructed to assess its ability to predict CLD/death.

RESULTS

We studied 141 infants at a mean (SD) gestation and birthweight of 26 (1.4) weeks and 952 (235) g, respectively. Five variables were identified that were independently associated with CLD/death (gestation at birth, PDA diameter, maximum flow velocity, LV output, and LV a' wave). The PDAsc had a range from 0 (low risk) to 13 (high risk). Infants who developed CLD/death had a higher score than those who did not (7.3 [1.8] vs 3.8 [2.0], P < .001). PDAsc had an area under the curve of 0.92 (95% CI 0.86-0.97, P < .001) for the ability to predict CLD/death. A PDAsc cut-off of 5 has sensitivity and specificity of 92% and 87%, and positive and negative predictive values of 92% and 82%, respectively.

CONCLUSIONS

A PDAsc on day 2 can predict the later occurrence of CLD/death further highlighting the association between PDA significance and morbidity.

Lung function in very preterm infants with patent ductus arteriosus under conservative management: an observational study

Background

Persistent patent ductus arteriosus (PDA) during hospitalization is thought to be associated with adverse pulmonary outcomes in very preterm infants. This observational study aimed to compare the lung function in very preterm infants with and without PDA at discharge.

Methods

Very preterm infants, admitted to our neonatal intensive unit, who required respiratory support soon after birth and had undergone a lung function test at discharge, were enrolled. Infants with a need for positive-pressure support (either an invasive ventilator, or nasal continuous positive airway pressure without oxygen) or supplemental oxygen at a postmenstrual age of 36 weeks were defined as having bronchopulmonary dysplasia (BPD). Echocardiography was performed weekly for each of the very preterm infants with PDA to confirm closure of the PDA. The data were collected retrospectively.

Results

Fifty-two very preterm infants received lung function tests before discharge during the study period, 28 of whom had PDA and received conservative management, and 20 who did not. The other 4 infants who were given active treatment for PDA were excluded. Gestational age was significantly smaller in the PDA group than in the no-PDA group (27.1 ± 2.0 vs. 28.6 ± 1.6 weeks, p = 0.009). Birth weight did not differ significantly in those with and those without PDA (0.98 ± 0.26 vs. 1.12 ± 0.26 kg, p = 0.074). Significantly more infants with PDA had BPD (p = 0.002) and required respiratory support for a longer period (p = 0.001) than those without PDA. However, functional residual capacity (ml/kg) at discharge was comparable between the two groups after adjusting for gestational age and postmenstrual age at testing (21.6 ± 8.4 vs. 21.5 ± 6.7 ml/kg, p = 0.894). Other lung function test parameters were also comparable.

Conclusion

Under a definition of BPD (including infants needing CPAP but without oxygen) other than the conventional definition, the very preterm infants in our study who received conservative management for PDA had a higher percentage of BPD than the infants without PDA. The parameters of the lung function test and lung clearance index were comparable between these two groups at discharge.

N-Terminal Pro-B Type Natriuretic Peptide as a Marker of Bronchopulmonary Dysplasia or Death in Very Preterm Neonates: A Cohort Study

Background

Bronchopulmonary dysplasia (BPD) is a serious complication of preterm birth. Plasma N-terminal pro-B type natriuretic peptide (NT-proBNP) has been suggested as a marker that may predict BPD within a few days after birth.

Objectives

To investigate the association between NT-proBNP day three and bronchopulmonary dysplasia (BPD) or death and further to assess the impact of patent ductus arteriosus (PDA) on this association in neonates born before 32 gestational weeks.

Methods

A cohort study of 183 neonates born before 32 gestational weeks consecutively admitted to the Neonatal Intensive Care Unit, Aarhus University Hospital, Denmark. On day three plasma samples were collected and echocardiography carried out. NT-proBNP was measured by routine immunoassays. The combined outcome BPD or death was assessed at 36 weeks of postmenstrual age. Receiver operator characteristic (ROC) analysis was performed to determine the discrimination ability of NT-proBNP by the natural log continuous measure to recognize BPD or death. The association of BPD or death was assessed in relation to natural log NT-proBNP levels day three.

Results

The risk of BPD or death increased 1.7-fold with one unit increase of natural log NT-proBNP day three when adjusted for gestational age at birth (OR = 1.7, 95% CI 1.3; 2.3). The association was found both in neonates with and without a PDA. Adjusting for GA, PDA diameter, LA:Ao-ratio, or early onset sepsis did not change the estimate.

Conclusion

We found NT-proBNP to be associated with BPD or death in very preterm neonates. This association was not only explained by the PDA. We speculate that NT-proBNP may help the identification of neonates at risk of BPD as early as postnatal day three.

Outcomes of Early Ligation of Patent Ductus Arteriosus in Preterms, Multicenter Experience

Persistent ductal patency may have serious effects in preterm infants. Analysis of the results of different trials were inconclusive in determining whether medical or surgical closure of the ductus is preferable and what is the best timing for surgical intervention.The aim of this study was to evaluate the effect of timing of surgical closure of patent ductus arteriosus (PDA) on ventilatory, hemodynamic, and nutritional status of preterm infants.The authors retrospectively looked at the outcomes of surgical ligation of PDA from January 2010 to June 2014 at 2 Saudi neonatal intensive units at 2 tertiary care centers and the authors compared the results of early ligation (before 3 weeks) to the late ligation (after 3 weeks) regarding different hemodynamic, ventilatory, and nutritional parameters.A total of 120 preemies were included (75 preemies with early ligation and 45 with late ligation of PDA). The early ligation group had shorter duration of assisted ventilation of 10 (8-37) days as compared with 37 (26-90) days in the late ligation group (P < 0.05). The median fraction of inspired oxygen, needed to maintain good oxygen saturation in patients, was higher in the late ligation group [0.29 (0.21-0.70)] than in the early group [0.23 (0.21-0.55)] at 24  hours postoperatively. Full oral feeding was achieved earlier in the early ligation group than in the late group, 29 (15-73) days of life versus 53 (34-118) days of life, respectively (P < 0.05). Body weight at 36 weeks postconceptional age was higher in the early group--2100 (1350-2800) g--than in the late group-1790 (1270-2300) g--(P < 0.05).Our study demonstrated that earlier surgical ligation of the PDA in preterm infants has a more favorable nutritional and ventilatory outcome.

PDA ligation and health outcomes: a meta-analysis

BACKGROUND AND OBJECTIVE

Patent ductus arteriosus (PDA) ligation has been variably associated with neonatal morbidities and neurodevelopmental impairment (NDI). The objective was to systematically review and meta-analyze the impact of PDA ligation in preterm infants at <32 weeks' gestation on the risk of mortality, severe neonatal morbidities, and NDI in early childhood.

METHODS

Medline, Embase, Cochrane Central Register of Controlled Trials, Education Resources Information Centre (ERIC), Cumulative Index to Nursing and Allied Health (CINAHL), PsycINFO, and the Dissertation database were searched (1947 through August 2013). Risk of bias was assessed by using the Newcastle-Ottawa Scale and the Cochrane Risk of Bias tool. Meta-analyses were performed by using a random-effects model. Unadjusted and adjusted odds ratios (aORs) with 95% confidence intervals (CIs) were pooled when appropriate.

RESULTS

Thirty-nine cohort studies and 1 randomized controlled trial were included. Nearly all cohort studies had at least moderate risk of bias mainly due to failure to adjust for survival bias and important postnatal preligation confounders such as ventilator dependence, intraventricular hemorrhage, and sepsis. Compared with medical treatment, surgical ligation was associated with increases in NDI (aOR: 1.54; 95% CI: 1.01-2.33), chronic lung disease (aOR: 2.51; 95% CI: 1.98-3.18), and severe retinopathy of prematurity (aOR: 2.23; 95% CI: 1.62-3.08) but with a reduction in mortality (aOR: 0.54; 95% CI: 0.38-0.77). There was no difference in the composite outcome of death or NDI in early childhood (aOR: 0.95; 95% CI: 0.58-1.57).

CONCLUSIONS

Surgical ligation of PDA is associated with reduced mortality, but surviving infants are at increased risk of NDI. However, there is a lack of studies addressing survival bias and confounding by indication.

Adjunctive drug therapies for treatment of respiratory diseases in the newborn: based on evidence or habit?

Respiratory distress syndrome is a disease of prematurity and is caused by a relative deficiency of endogenous surfactant production. Respiratory distress syndrome is the most common cause of mortality and morbidity in the newborn population and the standard of care is to provide exogenous surfactant therapy. This saves lives and reduces respiratory complications but, despite treatment, a significant proportion of these infants go onto develop chronic lung disease, the severest form of which is bronchopulmonary dysplasia. Once developed, this is a multisystem disease and treatment is mostly supportive by using various therapeutic adjuncts. Some of these have been proven to be safe and effective in large randomized, controlled trials but similar evidence for other drugs is lacking. The aim of this paper is to provide an overview and critically appraise the available scientific evidence for or against their use in routine practice.