The treatment of patent ductus arteriosus in preterm infants. A review and overview of randomized trials

Covariation of changing patent ductus arteriosus management and preterm infant outcomes in Pediatrix neonatal intensive care units

OBJECTIVE

To test the hypothesis that NICU-specific preterm infant outcomes co-vary with changes in local patent ductus arteriosus (PDA) management.

STUDY DESIGN

This retrospective multicenter study examined NICU-specific aggregated data for infants born 400-1499 g (VLBW) in the Pediatrix Clinical Data Warehouse. For each NICU and each year 2006-2016 we calculated proportion of infants receiving cyclooxygenase inhibitor (COXI) and/or PDA ligation and determined NICU-specific changes in these therapies between consecutive years. We examined relationships between NICU-specific changes in COXI/ligation and concurrent changes in local adjusted in-hospital outcomes.

RESULTS

In 5678 observations of change at 259 NICUs summarizing 78,105 infants, between-year decreases in NICU-specific proportion treated with COXI/ligation were associated with concurrent increases in local mortality and decreases in BPD among infants 400-749 g, and with decreased pulmonary hemorrhage in larger infants.

CONCLUSIONS

NICU-specific adjusted mortality, BPD, and pulmonary hemorrhage rates co-vary with changes in local COXI/ligation rates in some VLBW infant subgroups.

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.

Association of Co-Exposure of Antenatal Steroid and Prophylactic Indomethacin with Spontaneous Intestinal Perforation

OBJECTIVE

To evaluate the association of a combined exposure to antenatal steroids and prophylactic indomethacin with the outcome of spontaneous intestinal perforation (SIP) among neonates born at <26 weeks of gestation or <750 g birth weight.

STUDY DESIGN

We conducted a retrospective study of preterm infants admitted to Canadian Neonatal Network units between 2010 and 2018. Infants were classified into 2 groups based on receipt of antenatal steroids; the latter subgrouped as recent (≤7 days before birth) or latent (>7 days before birth) exposures. The co-exposure was prophylactic indomethacin. The primary outcome was SIP. Multivariable logistic regression analysis was used to calculate aORs.

RESULTS

Among 4720 eligible infants, 4121 (87%) received antenatal steroids and 1045 (22.1%) received prophylactic indomethacin. Among infants exposed to antenatal steroids, those who received prophylactic indomethacin had higher odds of SIP (aOR 1.61, 95% CI 1.14-2.28) compared with no prophylactic indomethacin. Subgroup analyses revealed recent antenatal steroids exposure with prophylactic indomethacin had higher odds of SIP (aOR 1.67, 95% CI 1.15-2.43), but latent antenatal steroids exposure with prophylactic indomethacin did not (aOR 1.24, 95% CI 0.48-3.21), compared with the respective groups with no prophylactic indomethacin. Among those not exposed to antenatal steroids, mortality was lower among those who received prophylactic indomethacin (aOR 0.45, 95% CI 0.28-0.73) compared with no prophylactic indomethacin.

CONCLUSIONS

In preterm neonates of <26 weeks of gestation or birth weight <750 g, co-exposure of antenatal steroids and prophylactic indomethacin was associated with SIP, especially if antenatal steroids was received within 7 days before birth. Among those unexposed to antenatal steroids, prophylactic indomethacin was associated with lower odds of mortality.

Patent Ductus Arteriosus Clinical Trials: Lessons Learned and Future Directions

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

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

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

Prophylactic intravenous paracetamol use in extremely premature infants for patent ductus arteriosus

OBJECTIVES

Patency of ductus arteriosus (PDA) is a very common problem among extremely low birth weight infants (ELBW). Hemodynamic instability caused by PDA is associated with important morbidities. This study aims to evaluate the effects of prophylactic intravenous paracetamol on the hemodynamically significant patent ductus arteriosus (hsPDA).

METHODS

A total of 75 infants of <28 week-gestational age were enrolled into the study which was retrospective. Prophylactic paracetamol as the experimental group and none-prophylaxis group as the control group were compared in the study.

RESULTS

There were 35 subjects in the prophylactic paracetamol group (PPG), and 40 in the control group. Primary outcome measures were ductal closure, ductal diameter, grade 3-4 IVH, and repeated ibuprofen need for the treatment of hsPDA. At the time of the evaluation by echo, hsPDA, and the diameter of the ductus higher than 1 mm were found significantly lower in the PPG (p=0.004 and p=0.013). Additionally, the repeated course of ibuprofen was significantly lower in the PPG (p=0.025). Secondary outcomes were the other perinatal morbidities. According to the results of the study, the male gender is 6.6, and the paracetamol use is 5.5 times more likely to suffer from ROP.

CONCLUSIONS

The results of the study indicated that prophylactic paracetamol use in ELBW infants decreases the likelihood of hsPDA. The repeated course of ibuprofen for the treatment of hsPDA can be reduced. Furthermore, it can be understood that while prophylactic use of paracetamol is preventive for intraventricular hemorrhage, it does not function in the same way for retinopathy of prematurity or bronchopulmonary dysplasia. It might even worse the retinopathy of prematurity. Further prospective randomized controlled and larger sample-sized studies are needed.

Indomethacin dosing strategy and neonatal patent ductus arteriosus closure

BACKGROUND

Few studies exist that have evaluated the effects of indomethacin dosing frequency as a factor associated with successful patent ductus arteriosus closure in very low birth weight neonates. The objective of this study is to determine if indomethacin dosing strategy is associated with efficacy for initial patent ductus arteriosus management in very low birth weight neonates.

METHODS

This retrospective review compared every 12 hour and every 24 hour indomethacin regimens primarily for efficacy in initial patent ductus arteriosus management, defined as an absence of repeat medical and/or surgical treatment, and secondarily for safety in both univariate and multivariate models.

RESULTS

One hundred three very low birth weight neonates were included: 56 (54%) received every 12 hour and 47 (46%) underwent every 24 hour indomethacin dosing. Repeat medical and/or surgical patent ductus arteriosus treatment rates were similar between groups. Less ligation of the patent ductus arteriosus occurred with every 12 hour versus every 24 hour dosing (11% vs. 26%, p = 0.05), though this effect was mitigated controlling for birth weight and gestational age. Renal function, respiratory outcomes, feeding outcomes, length of stay, and mortality were similar between groups.

CONCLUSIONS

Neither the every 12 hour nor the every 24 hour indomethacin regimen demonstrated inferior efficacy or safety for initial management of patent ductus arteriosus. Further prospective analysis of indomethacin dosing strategy is warranted.

Optimal timing of video-assisted thoracoscopic surgery for patent ductus arteriosus in preterm infants born at ≤ 28 weeks of gestation

BACKGROUND

Video-assisted thoracoscopic surgery for patent ductus arteriosus (VATS-PDA) is an alternative surgical procedure to open chest surgery, even in premature infants. This study investigated whether the timing of VATS-PDA has a prognostic impact in premature infants whose operative indication was determined according to the symptomatic PDA and the ineffectiveness of or contraindication to indomethacine therapy.

METHODS

We studied 49 infants born at or before 28 weeks of gestation who were admitted to the neonatal intensive care unit between January 2004 and June 2016, and who underwent VATS-PDA. The patients were divided into two groups according to median age at the time of surgery (early group, 24 infants who underwent surgery at ≤ 24 days of life; late group, 25 infants who underwent surgery at ≥ 25 days of life).

RESULTS

No significant differences were found in bodyweight at 30 days of age and 40 weeks of corrected gestational age between the groups. The timing of surgery did not affect the operative procedure or postoperative complications. In addition, no differences were observed between the early and late groups in terms of complications associated with prematurity, including intraventricular hemorrhage, incidence and severity of bronchopulmonary dysplasia, and necrotizing enteropathy.

CONCLUSION

Video-assisted thoracoscopic surgery for patent ductus arteriosus can be safely performed in premature infants without a preferential timing for the intervention, suggesting that this procedure allows for an elective basis approach after heart failure management with conservative and/or drug therapy in premature infants with PDA.

Tratamiento farmacológico del conducto arterioso permeable en recién nacidos prematuros

Introducción. Por lo general, el manejo farmacológico del conducto arterioso permeable (CAP) comprende inhibidores no selectivos de la enzima ciclooxigenasa, en especial indometacina e ibuprofeno. En años recientes también se ha sugerido al acetaminofén como alternativa terapéutica.Objetivo. Realizar una revisión narrativa de la literatura acerca del manejo farmacológico del CAP.Materiales y métodos. Se realizó una búsqueda estructurada de la literatura en las bases de datos ProQuest, EBSCO, ScienceDirect, PubMed, LILACS, Embase, Trip Database, SciELO y Cochrane Library con los términos “Ductus Arteriosus, patent AND therapeutics”; “Ductus Arteriosus, patent AND indometacin”; “Ductus Arteriosus, Patent AND ibuprofen”, y “Ductus Arteriosus, patent AND acetaminophen”. La búsqueda se hizo en inglés con sus equivalentes en español.Resultados. Se encontraron 69 artículos con información relevante para llevar a cabo la presente revisión.Conclusiones. En neonatos prematuros, la base del tratamiento farmacológico del CAP continúa siendo los inhibidores no selectivos de la ciclooxigenasa, indometacina e ibuprofeno, ambos con perfiles similares de seguridad y eficacia. La evidencia disponible sugiere que el acetaminofén podría constituir una alternativa útil para el manejo, pero resulta insuficiente para realizar recomendaciones definitivas respecto a la eficacia y seguridad de este medicamento.

Is high platelet distribution width in the first hours of life can predict hemodynamically significant patent ductus arteriosus in preterm newborns?

Aim: To determine whether there is any association between platelet indices within the first hours of life and hemodynamically significant patent ductus arteriosus (hsPDA) in preterm newborns.Patient and methods: A total of 100 preterm infants, gestational age <32 weeks and birth weight <1500 g were analyzed in the study. Complete blood counts obtained within the first 6 hours of life were evaluated for platelet parameters and compared for patent ductus arteriosus (PDA) status.Results: We included 50 infants with hsPDA and 50 controls. Mean gestational week of patients were 28.8 ± 2.4 weeks and mean birth weight of the patients were 1237.5 ± 406 g. Platelet distribution width (PDW) is higher in PDA group compared with the control group (p = .023). The cutoff value of PDW is 11.45 fL for hsPDA with 65% sensitivity and 66% specificity. The other blood parameters including platelet count, platelet mass, and mean platelet volume (MPV) were no statistically different between the two groups. Also, there was no association with the platelet count and the response to the medical therapy.Conclusions: There is no association between hsPDA and the platelet count, platelet mass or MPV in the first day of life. We determined that hsPDA patency was significantly associated with a higher first day PDW level, which is a more specific indicator of platelet activation than other platelet parameters.

Turkish Neonatal Society guideline on the management of patent ductus arteriosus in preterm infants

Ductus arteriosus is a physiologic phenomenon in utero and it closes spontaneously in term babies. The closure is problematic in preterm infants due to the intrinsic properties of the preterm ductus arteriosus tissue. Although patent ductus arteriosus has been reported to be associated with many adverse outcomes in this population, treatment has not led to a decrease in outcomes such as bronchopulmonary dysplasia. Treatment modalities also have their own risks and restrictions. The aim of the "Turkish Neonatal Society guidelines for the management of patent ductus arteriosus in preterm babies" is to standardize the diagnosis and treatment of patent ductus arteriosus in preterm infants by combining the current scientific data and the resources of our country.

Early echocardiography does not predict subsequent treatment of symptomatic patent ductus arteriosus in extremely preterm infants

AIM

To determine whether early echocardiographic ductal parameters identified infants who subsequently received medical or surgical treatment of the patent ductus arteriosus (PDA).

METHODS

Infants <29 weeks had PDA size in 2D and colour, flow velocity and patterns obtained on days 1 and 3. Infants were followed up to identify those subsequently receiving treatment for symptomatic PDA by clinicians who were unaware of scan results. Receiver operator characteristics curves and logistic regression were performed.

RESULTS

Sixty infants were studied. Mean (SD) gestation and birthweight were 25.8 (1.5) weeks and 817 (190) grams, respectively. Twenty-four (40%) infants received medical treatment, and nine (15%) infants received surgical ligation of PDA at a median age of 12 and 37 days, respectively. PDA size on days 1 and 3, change in ductal size between days 1 and 3, flow pattern/velocity did not predict whether infants subsequently received medical or surgical management of PDA. Using logistic regression, gestation (p = 0.006) was the only factor that predicted whether infants would subsequently receive medical or surgical treatment for PDA in this cohort.

CONCLUSION

Echocardiographic ductal parameters on day 1 or 3 did not identify infants who received PDA treatment. Gestation was the most powerful predictor for receiving medical or surgical treatment of PDA.

International perspective on management of a patent ductus arteriosus: Lessons learned

Whereas association between a patent ductus arteriosus (PDA) and neonatal morbidities has been well described, consensus has not been reached on whether the relationship is causal, on benefit of (or lack of) treatment, on factors guiding the 'need to treat', and on treatment strategies. Trials to date have primarily focused on the narrow outcome of successful ductal closure. Evidence from several retrospective studies has suggested that management may be modified with increased use of conservative treatment. A paradigm shift has resulted in decreased use of treatments to close the PDA in some centres. This approach cites the lack of demonstrable improvement in short- and long-term respiratory and neurodevelopmental outcomes as an argument. This article reviews current understanding of the wide variation in practice at either institutional, regional, national, or international level. It discusses the potential contributors to variability in diagnostic ascertainment and therapeutic intervention.

Changing patterns of patent ductus arteriosus surgical ligation in the United States

Optimal management of patent ductus arteriosus (PDA) is unclear. One treatment, surgical ligation, is associated with adverse outcomes. We reviewed data from the Kids' Inpatient Database (2000-2012) to determine if PDA ligation rates: (1) changed over time, (2) varied geographically, or (3) influenced surgical complication rates. In 2012, 47,900 infants <1500g birth weight were born in the United States, including 2,800 undergoing PDA ligation (5.9%). Ligation was more likely in infants <1000g (85.9% vs. 46.2%), and associated with necrotizing enterocolitis (59.2% vs. 37.5%), BPD (54.6% vs. 15.2%), severe intraventricular hemorrhage (16.4% vs. 5.3%), and hospital transfer (37.6% vs. 16.4%). Ligation rates peaked in 2006 at 87.4 per 1000 hospital births, dropping to 58.8 in 2012, and were consistently higher in Western states. Infants undergoing ligation were more likely to experience comorbidities. Rates of ligation-associated vocal cord paralysis increased over time (1.2-3.9%); however, mortality decreased (12.4-6.5%). Thus, PDA ligation has become less frequent, although infants being ligated are smaller and more medically complex. Despite increase in some complications, mortality rates improved perhaps reflecting advances in care.

The use of non-steroidal anti-inflammatory drugs for patent ductus arteriosus closure in preterm infants

Over the last four decades, non-steroidal anti-inflammatory drugs have been widely used to induce closure of the patent ductus arteriosus (PDA) in preterm infants. Evidence to support this practice is lacking, despite performance of >50 randomized trials. The credibility of those trials may have been compromised by high rates of open treatment in controls, era of study prior to advent of modern practices, or inclusion of insufficient numbers of very immature infants. Meta-analyses show little impact of those factors on main conclusions. Essentially all trials reporting important long-term outcomes (other than mortality) initiated treatment within five days after birth, so no evidence regarding later treatment is available. Accruing clinical experience suggests that long-term outcomes are not compromised, and may be improved, with non-interventional management strategies. Future studies to identify preterm infants at greatest risk of potential harm from a persistent PDA, particularly after the second postnatal week, are urgently needed.

Prophylactic Indomethacin Revisited

Persistent patency of the ductus arteriosus (PDA) has challenged neonatologists for more than 40 years.^, Surgical ligation of the ductus was first performed in children nearly 80 years ago and proved that prevention of prolonged exposure to left-to-right shunting through the ductus arteriosus improved pulmonary, cardiac, and systemic outcomes. In the 1970s, the discovery that nonsteroidal anti-inflammatory drugs could induce PDA closure^– and are effective in infants born preterm^, provided neonatologists with a pharmacologic alternative to surgery. The clear advantages, however, of having a medical approach have been clouded by conflicting information on the long-term benefits of treatment, disagreement regarding the clinical indicators that warrant treatment for PDA, optimal drug choice, preferred dosing regimens, and indecision regarding the best time to treat a select population of fragile preterm infants.

The nitric oxide synthase 2 pathway is targeted by both pro- and anti-inflammatory treatments in the immature human intestine

BACKGROUND AND AIM

NO synthase 2 (NOS2) was recently identified as one the most overexpressed genes in intestinal samples of premature infants with necrotizing enterocolitis (NEC). NOS2 is widely implicated in the processes of epithelial cell injury/apoptosis and host immune defense but its specific role in inflammation of the immature human intestinal mucosa remains unclear. Interestingly, factors that prevent NEC such as epidermal growth factor (EGF) attenuate the inflammatory response in the mid-gestation human small intestine using serum-free organ culture while drugs that are associated with NEC occurrence such as the non-steroidal anti-inflammatory drug, indomethacin (INDO), exert multiple detrimental effects on the immature human intestine. In this study we investigate the potential role of NOS2 in modulating the gut inflammatory response under protective and stressful conditions by determining the expression profile of NOS2 and its downstream pathways in the immature intestine.

METHODS

Gene expression profiles of cultured mid-gestation human intestinal explants were investigated in the absence or presence of a physiological concentration of EGF (50 ng/ml) or 1 μM INDO for 48 h using Illumina whole genome microarrays, Ingenuity Pathway Analysis software and quantitative PCR to investigate the expression of NOS2 and NOS2-pathway related genes.

RESULTS

In the immature intestine, NOS2 expression was found to be increased by EGF and repressed by INDO. Bioinformatic analysis identified differentially regulated pathways where NOS2 is known to play an important role including citrulline/arginine metabolism, epithelial cell junctions and oxidative stress. At the individual gene level, we identified many differentially expressed genes of the citrulline/arginine metabolism pathway such as ARG1, ARG2, GLS, OAT and OTC in response to EGF and INDO. Gene expression of tight junction components such as CLDN1, CLDN2, CLDN7 and OCN and of antioxidant markers such as DUOX2, GPX2, SOD2 were also found to be differentially modulated by EGF and INDO.

CONCLUSION

These results suggest that the protective effect of EGF and the deleterious influence of INDO on the immature intestine could be mediated via regulation of NOS2. Pathways downstream of NOS2 involved with these effects include metabolism linked to NO production, epithelial barrier permeability and antioxidant expression. These results suggest that NOS2 is a likely regulator of the inflammatory response in the immature human gut and may provide a mechanistic basis for the protective effect of EGF and the deleterious effects of INDO.

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.

[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.

Current controversies in the management of patent ductus arteriosus in preterm infants

OBJECTIVE

Patent ductus arteriosus is very commonly seen in very low birth weight (VLBW) infants, affecting about one-third. The present review tries to identify the group of VLBW infants who need active intervention in day-to-day practice and to determine the mode of intervention, based on current published literatures.

METHODS

We searched the Cochrane library, MEDLINE, EMBASE and CINAHL databases, and reference that of identified trials.

RESULTS AND CONCLUSIONS

Preterm infants with a birth weight of <800g are at risk of significant morbidity and mortality from PDA; it would be reasonable to treat them when symptomatic or if requiring positive pressure ventilator support. Those weighing >800g are unlikely to need treatment unless they are ventilator-dependent or show evidence of congestive heart failure.

Clinical and echocardiographic characteristics associated with the evolution of the ductus arteriosus in the neonate with birth weight lower than 1,500g

Objective:

To identify clinical and echocardiographic parameters associated with the evolution of the ductus arteriosus in neonates with birth weight lower than 1,500g.

Methods:

Retrospective study of 119 neonates in which clinical parameters (Prenatal: maternal age, risk of infection and chorioamnionitis, use of corticosteroid, mode of delivery and gestational age. Perinatal: weight, Apgar score, gender and birth weight/gestational age classification; Postnatal: use of surfactant, sepsis, fluid intake, heart murmur, heart rate, precordial movement and pulses, use of diuretics, oxygenation index, desaturation/apnea, ventilatory support, food intolerance, chest radiography, renal function, hemodynamic instability, and metabolic changes) and echocardiographic parameters (ductus arteriosus diameter, ductus arteriosus/weight ratio, left atrium/ aorta ratio, left ventricular diastolic diameter, and transductal flow direction, pattern and velocity) were analyzed. The clinical and echocardiographic parameters analyzed were considered statistically significant when p<0.05.

Results:

In the 119 neonates, the incidence of patent ductus arteriosus was 61.3%; 56 received treatment (46 pharmacological and 10 surgical treatment), 11 had spontaneous closure, 4 died, and 2 were discharged with patent ductus arteriosus. A higher incidence of chorioamnionitis, use of surfactant, lower weight and gestational age, sepsis, heart murmur, ventilatory support and worse oxygenation indices were observed in the neonates receiving treatment. The group with spontaneous closure had a smaller ductus arteriosus diameter, lower ductus arteriosus/weight ratio, and higher transductal flow velocity.

Conclusion:

Based on clinical and echocardiographic parameters, the neonates with spontaneous closure of the ductus arteriosus could be differentiated from those who required treatment.

Serial echocardiography in very preterm infants: a pilot randomized trial

AIM

To determine whether routine echocardiography increases diagnosis and treatment for patent ductus arteriosus (PDA) and whether randomized nondisclosure is a feasible strategy for studying PDA management.

METHODS

Two-centre, pilot randomized, controlled trial. 88 infants with birth weights ≤1250 grams and gestational ages ≤30 weeks were randomized to disclosure or nondisclosure of serial echocardiogram findings. Echocardiograms were performed at 3-5 and 7-10 days of life. The primary outcome was time to regain birth weight.

RESULTS

100% of echocardiograms in the disclosure group were disclosed; 16% (echocardiogram #1) and 29% (echocardiogram #2) were disclosed in the nondisclosure group. There was a statistically nonsignificant decrease in drug therapy for PDA in the nondisclosure group (adjusted odds ratio [AOR] 0.56, 95% confidence interval [CI] 0.24-1.34). There was no difference in time to regain birth weight or in other important neonatal outcomes. However, infants in the nondisclosure group were more likely to demonstrate appropriate weight loss and then regain birth weight within 7-14 days (AOR 2.64, 95% CI 1.08-6.44).

CONCLUSION

Randomized nondisclosure of echocardiograms is a feasible strategy for evaluation of approaches to PDA management in very preterm infants. Avoidance of routine echocardiography may reduce drug therapy for PDA without adverse clinical effects.

Assessment of PDA shunt and systemic blood flow in newborns using cardiac MRI

Patent ductus arteriosus (PDA) remains common in preterm newborns, but uncertainty over optimal management is perpetuated by clinicians' inability to quantify its true haemodynamic impact. Our aim was to develop a technique to quantify ductal shunt volume and the effect of PDA on systemic blood flow volume in neonates. Phase contrast MRI sequences were optimized to quantify left ventricular output (LVO) and blood flow in the distal superior vena cava (SVC) (below the azygos vein insertion), descending aorta (DAo) and azygos vein. Total systemic flow was measured as SVC + DAo-azygos flow. Echo measures were included and correlated to shunt volumes. 75 infants with median (range) corrected gestation 33(+6) (26(+4) -38(+6) ) weeks were assessed. PDA was present in 15. In 60 infants without PDA, LVO matched total systemic flow (mean difference 2.06 ml/kg/min, repeatability index 13.2%). In PDA infants, ductal shunt volume was 7.9-74.2% of LVO. Multiple linear regression analysis correcting for gestational age showed that there was a significant association between ductal shunt volume and decreased upper and lower body flow (p = 0.01 and p < 0.001). However, upper body blood flow volumes were within the control group 95% confidence limits in all 15 infants with PDA, and lower body flow volumes within the control group limits in 12 infants with PDA. Echocardiographic assessment of reversed diastolic flow in the descending aorta had the strongest correlation with ductal shunt volume. We have demonstrated that quantification of shunt volume is feasible in neonates. In the presence of high volume ductal shunting the upper and lower body flow volume are somewhat reduced, but levels remain within or close to the normal range for preterm infants.

Primary surgical closure should be considered in premature neonates with large patent ductus arteriosus

BACKGROUND

Treatment for patent ductus arteriosus (PDA) in premature infants can consist of medical or surgical approaches. The appropriate therapeutic regimen remains contentious. This study evaluated the role of surgery in improving the survival of premature neonates weighing less than 1,500 g with PDA.

MATERIALS AND METHODS

From January 2008 to June 2011, 68 patients weighing less than 1,500 g with PDA were enrolled. The patients were divided into three groups: a group managed only by medical treatment (group I), a group requiring surgery after medical treatment (group II), and a group requiring primary surgical treatment (group III).

RESULTS

The rate of conversion to surgical methods due to failed medical treatment was 67.6% (25/37) in the patients with large PDA (≥2 mm in diameter). The number of patients who could be managed with medical treatment was nine which was only 20.5% (9/44) of the patients with large PDA. There was no surgery-related mortality. Group III displayed a statistically significantly low rate of development of bronchopulmonary dysplasia (BPD) (p=0.008). The mechanical ventilation time was significantly longer in group II (p=0.002).

CONCLUSION

Medical treatment has a high failure rate in infants weighing less than 1,500 g with PDA exceeding 2.0 mm. Surgical closure following medical treatment requires a longer mechanical ventilation time and increases the incidence of BPD. Primary surgical closure of PDA exceeding 2.0 mm in the infants weighing less than 1,500 g should be considered to reduce mortality and long-term morbidity events including BPD.

Management of patent ductus arteriosus in preterm infants: clinical judgment might be a fair option

OBJECTIVE

The objective of this study was to find out the percentage of preterm infants that needed treatment for patent ductus arteriosus (PDA), when treatment decision was based on clinical signs and symptoms, besides echocardiographic findings.

METHODS

Daily echocardiographic evaluation was conducted in 39 preterms ≤29(6/7) weeks' gestation. Patients with ductus arteriosus were closely followed-up for clinical symptoms of PDA for treatment decision until ductus arteriosus was closed either spontaneously or by treatment.

RESULTS

PDA was found in 25 (64%) infants. Mean gestational age and birth weight (BW) of the patients with PDA were 27.8 ± 1.2 and 998 ± 221 g, respectively. PDA closed spontaneously or had minimal ductal shunting before any signs and symptoms attributable to PDA were observed in 16 (41%) infants. Mean ductus size/BW ratio and mean left atrial/aortic root ratio were significantly higher in 9 (23%) symptomatic patients (2.06 ± 0.75 versus 1.32 ± 0.75 mm, p = 0.012 and 1.31 ± 0.52 versus 1.19 ± 0.2 mm, p = 0.043, respectively). PDA closure was observed after the first dose of ibuprofen in six of nine patients.

CONCLUSION

Correlation of clinical signs with echocardiographic findings for the decision of PDA treatment can be appropriate to prevent unnecessary medical treatments.

Therapeutic strategies, including a high surgical ligation rate, for patent ductus arteriosus closure in extremely premature infants in a North American centre

OBJECTIVE

To document the rate of surgical ligation of a patent ductus arteriosus (PDA) in extremely premature infants who had received more than one course of indomethacin. Outcomes were compared among three subgroups (ligation, further indomethacin and no further treatment) of infants who received at least one course of indomethacin, and between two subgroups (one course of indomethacin and more than one course) among infants who underwent ligation.

STUDY DESIGN

A retrospective chart review of all 23 weeks+0 days to 26 weeks+6 days' gestational age infants with a PDA born between 1994 and 2005 was performed. Secondary outcomes were compared among the subgroups.

RESULTS

The final study population consisted of 196 extremely premature infants with a PDA. The rate of surgical ligation in the 88 infants who received more than one course of indomethacin was 64%. The ligation subgroup, in comparison with the no further treatment subgroup, spent a greater median time on mechanical ventilation (39 versus 29 days, P<0.001) and in hospital (115 versus 92 days P=0.002), while trending toward lower mortality (18% versus 40%, P=0.07). The PDA closed following the first course of indomethacin in only 20% of infants.

CONCLUSIONS

A majority of extremely premature infants receiving more than one course of indomethacin underwent surgical ligation. Repeated indomethacin courses were generally well tolerated, but were mostly unsuccessful. Ligation appears to have potential risks and benefits. A randomized trial should be performed after studies define a hemodynamically significant PDA that will result in morbidity and/or mortality unless treated.

Functional echocardiography in staging for ductal disease severity : role in predicting outcomes

Equipoise persists as to the issue of assigning haemodynamic and clinical significance to a patent ductus arteriosus (PDA). The objective was to ascertain whether echocardiographic scoring of a PDA correlates with outcomes. Unit electronic data base was accessed to identify infants less than 32 weeks' gestation who received ibuprofen for medical closure of the PDA during the period June 2010-June 2012. Echocardiographic score was assigned on the day of therapy and the infants were prospectively followed up to ascertain the occurrence of chronic lung disease (CLD). Logistic regression analysis was used to estimate the association between composite score and occurrence of CLD. Fifty-two infants were identified out of which 27 (52 %) subsequently developed CLD. Echocardiographic parameters were of a significantly higher magnitude in infants who later developed CLD. The median composite score (inter-quartile range) was also significantly higher in this group 26 (24-26) vs. 19 (17-20), p < 0.001). Higher composite scores were associated with increased risk of developing CLD; for every one point increase in composite score, the odds of CLD increased by 78 % (odds ratio (95 % CI): 1.78 (1.35-2.34); p < 0.001).

CONCLUSIONS

Infants with a high composite score, assigned according to the staging criteria at the time of treatment, were noted to have a higher incidence of subsequent CLD. Whether disease stratification can be the basis of further RCT's needs prospective evaluation.

Extremely low birth weight infants with patent ductus arteriosus: searching for the least invasiveness

Patent ductus arteriosus (PDA) is an important problem in premature infants. Extremely low birth weight infants (ELBWI) are so fragile with respect to surgical stress that minimally invasive procedures are required. We report 26 ELBWI cases with PDA who underwent surgical closure. All had failed indomethacin treatment, or it had been contraindicated. The mean gestational age at birth was 27 weeks (range, 24-38 weeks), and the mean birth weight was 960.96 g (range, 710-1440 g). The mean age at operation was 18.06 days (range, 7-34 days), and the mean body weight at operation was 989.42 g (range, 680-1460 g). There was no surgery-related mortality or morbidity. Our surgical procedures consisted of posterior muscle-sparing thoracotomy, clipping the PDA and no ligation, and closing the thorax without a tube thoracostomy. Muscle-sparing thoracotomy reduces the likelihood of long-term physical impairment and deformity, the clipping technique minimizes the dissection of surrounding PDA tissue, and the thorax is closed without a tube. Nursing care is simplified, costs are reduced, and the number of chest x-rays needed postoperatively is reduced. We believe that surgical closure of PDA without chest tube drainage can be accomplished safely in premature infants.

Patent ductus arteriosus in premature neonates

Persistent patency of the ductus arteriosus is a major cause of morbidity and mortality in premature infants. In infants born prior to 28 weeks of gestation, a haemodynamically significant patent ductus arteriosus (PDA) can cause cardiovascular instability, exacerbate respiratory distress syndrome, prolong the need for assisted ventilation and increase the risk of bronchopulmonary dysplasia, intraventricular haemorrhage, renal dysfunction, cerebral palsy and mortality. We review the pathophysiology, clinical features and assessment of haemodynamic significance, and provide a rigorous appraisal of the quality of evidence to support current medical and surgical management of PDA of prematurity. Cyclo-oxygenase inhibitors such as indomethacin and ibuprofen remain the mainstay of medical therapy for PDA, and can be used both for prophylaxis as well as for rescue therapy to achieve PDA closure. Surgical ligation is also effective and is used in infants who do not respond to medical management. Although both medical and surgical treatment have proven efficacy in closing the ductus, both modalities are associated with significant adverse effects. Because the ductus does undergo spontaneous closure in some premature infants, improved and early identification of infants most likely to develop a symptomatic PDA could help in directing treatment to the at-risk infants and allow others to receive expectant management.

Patent ductus arteriosus: are current neonatal treatment options better or worse than no treatment at all?

Although a moderate-sized patent ductus arteriosus (PDA) needs to be closed by the time a child is 1-2 years old, there is great uncertainty about whether it needs to be closed during the neonatal period. Although 95% of neonatologists believe that a moderate-sized PDA should be closed if it persists in infants (born before 28 weeks) who still require mechanical ventilation, the number of neonatologists who treat a PDA when it occurs in infants who do not require mechanical ventilation varies widely. Both the high likelihood of spontaneous ductus closure and the absence of randomized controlled trials, specifically addressing the risks and benefits of neonatal ductus closure, add to the current uncertainty. New information suggests that early pharmacologic treatment has several important short-term benefits for the preterm newborn. By contrast, ductus ligation, while eliminating the detrimental effects of a PDA on lung development, may create its own set of morbidities that counteract many of the benefits derived from ductus closure.

The ductus arteriosus: a refined approach!

Although ongoing patency of the ductus arteriosus is common in small extremely preterm infants, consensus is lacking regarding its clinical significance and treatment strategies. Literature regarding likelihood of spontaneous closure, impact on neonatal morbidity and long-term outcomes, and adverse effects of intervention has led to uncertainty as to the best course of action. Enhancing the determination of hemodynamic significance and refining patient selection for therapeutic intervention will streamline the decision-making process. Targeted neonatal echocardiography performed by the clinician has gained popularity worldwide, and preliminary data show that it has the potential to optimize patient outcomes. We review the arguments for and against medical and surgical therapy, explore how targeted neonatal echocardiography used in conjunction with biomarkers may refine the treatment approach, and consider future directions in the field.

Evidence-based use of indomethacin and ibuprofen in the neonatal intensive care unit

Indomethacin and ibuprofen are potent inhibitors of prostaglandin synthesis. Neonates have been exposed to these compounds for more than 3 decades. Indomethacin is commonly used to prevent intraventricular hemorrhage (IVH), and both drugs are prescribed for the treatment or prevention of patent ductus arteriosus (PDA). This review examines the basis for indomethacin and ibuprofen use in the neonatal intensive care population. Despite the call for restrained use of each drug, the most immature infants are likely to need pharmacologic approaches to reduce high-grade IVH, avoid the need for PDA ligation, and preserve the opportunity for an optimal outcome.

Antenatal calcium channel blocker exposure and subsequent patent ductus arteriosus in extremely low-birth-weight infants

This study aimed to assess whether tocolytic fetal exposure to antenatal calcium channel blockers (aCCB) increases the risk for hemodynamically significant patent ductus arteriosus (hsPDA) in extremely low-birth-weight (ELBW) infants. This case-control study investigated ELBW infants (<1,000 g) without cardiac defects in a level 3 neonatal intensive care unit who had survived at least 7 days. Nifedipine was the only aCCB used for this study population. The measurements included the history of aCCB exposure, selected maternal data, hsPDA diagnosis, gestational age at birth, birth weight, mode of delivery, sex, maternal race, location of birth, Apgar scores, and selected neonatal morbidities. The end point of the study was hsPDA, defined as an echocardiographically confirmed PDA with clinical symptoms. A total of 180 infants met the study criteria. The diagnosis was hsPDA for 56% of these patients, 20% of whom had aCCB exposure. Of the infants without hsPDA, 11% had aCCB exposure (p = 0.09). No statistically significant associations were found between aCCB exposure and hsPDA after adjustment for gestational age (odds ratio [OR], 1.5; 95% confidence interval [CI], 0.6-3.7) or for gestational age and cumulative aCCB exposure of 100 mg or more (OR, 2.0; 95% CI, 0.6-6.5). A history of aCCB exposure does not appear to increase hsPDA risk in ELBW infants. Studies using neonatal serum nifedipine concentrations after antenatal exposure should be performed to confirm this conclusion.

Abdominal pathology requiring laparotomy in very preterm infants is associated with need for surgical closure of patent ductus arteriosus

BACKGROUND

Extensive intestinal surgery in very preterm infants and its influence on somatic growth is of major concern. There is little consensus as to which is the most appropriate surgical approach in extremely low-birth-weight infants with abdominal pathology. Laparotomy is currently advocated, but peritoneal drainage is also discussed.

OBJECTIVE

To study laparotomy as surgical intervention in newborn infants with less than 28 gestational weeks and to investigate associated mortality and morbidity and its impact on short-term growth.

STUDY DESIGN/METHODS

The study was a retrospective case-control study of newborn infants requiring laparotomy. All infants with gestational age less than 28 weeks who were subject to acute laparotomy in the neonatal period at Sahlgrenska University Hospital during a 5-year period (2003-2007) were included in the study (n = 20). The control group consisted of infants admitted to the unit with the same gestational age but not requiring laparotomy. Infants with severe malformations were excluded.

SUMMARY AND CONCLUSION

Extensive abdominal surgery was feasible in very preterm infants. Necrotizing enterocolitis dominated the abdominal pathology requiring surgery. Patent ductus arteriosus requiring surgical closure occurred more often in the lapatotomy group and in those diagnosed as necrotizing enterocolitis. There was no impact on first year somatic growth.

Gastrointestinal complications associated with ibuprofen therapy for patent ductus arteriosus

OBJECTIVE

To review intestinal complications associated with ibuprofen treatment of patent ductus arteriosus (PDA).

STUDY DESIGN

Data from preterm infants treated with ibuprofen were retrospectively reviewed. χ(2) test and Fischer's exact test were used for univariate analyses. Multivariate analyses with logistic regression modeling were used to identify risk factors.

RESULT

One hundred and two infants were treated with ibuprofen for PDA. Nine (9/102, 8.8%) infants developed spontaneous intestinal perforation (SIP), whereas 93/102 (91.2%) did not. The mean (± s.d.) gestational age (GA) at birth in infants with and without SIP was 25.2 (± 1.3) vs 27.6 (± 2.4) weeks (P=0.02) and the median (interquartile) length of stay (LOS) was 109.5 (91.0 to 116.5) vs 75.0 (53.0 to 94.5) days (P=0.002), respectively. The mean (± s.d.) age at starting ibuprofen was 3.3 (± 1.3) vs 5.8 (± 3.5) days in infants with and without SIP, respectively (P=0.03). In logistic regression analyses, increasing GA and later initiation of ibuprofen treatment were protective against risk of SIP; odds ratio, 95% confidence interval (OR, 95% CI)=0.26 (0.09 to 0.75), P=0.01 and 0.63 (0.41 to 0.95), P=0.03, respectively.

CONCLUSION

Infants at lower GA are at risk of SIP when treated early with ibuprofen for symptomatic PDA.

Clinical aspects of very-low-birthweight infants showing reopening of ductus arteriosus

BACKGROUND

Indomethacin is used to treat the hemodynamically significant patent ductus arteriosus in premature infants. Some infants show ductus arteriosus reopening after effective constriction by the drug. The purpose of this study was to examine the clinical characteristics of such infants.

METHODS

We studied 57 very-low-birthweight infants with effective constriction of patent ductus arteriosus by the initial course of indomethacin. They were classified into the reopened group if they developed hemodynamically significant patent ductus arteriosus again or into the closed group if they showed complete closure. Clinical characteristics were compared between the two groups.

RESULTS

Ductus arteriosus reopening was shown in 15 (26%) of the 57 infants. These 15 infants had successful clinical ductal closure after a subsequent course of indomethacin or oral mefenamic acid treatment or surgical ligation without any severe complications. Infants in the reopened group showed significantly higher rates of developing chronic lung disease at 36 weeks of gestation than those in the closed group (53% vs 18%; P= 0.009). Furthermore, multivariate logistic regression analysis revealed ductus arteriosus reopening was the only independent risk factor for developing chronic lung disease at 36 postconceptional weeks in this population (adjusted odds ratio, 6.1; 95% confidence interval, 1.4-31.2; P= 0.02).

CONCLUSIONS

Incomplete closure of the ductus arteriosus is associated with recurrence of a clinically significant patent ductus arteriosus and reopening of the ductus after initial closure with indomethacin is associated with chronic lung disease.

Doppler manifestations of ductal steal: role in decision making

Patent ductus arteriosus in extremely premature babies is associated with major neonatal morbidities such as necrotizing enterocolitis and intraventricular haemorrhage. Altered systemic blood flow and end-organ hypoperfusion are known associates of a haemodynamically significant ductus arteriosus where descending aorta blood flow profiles may reveal abnormal diastolic retrograde flow. A preterm neonate was noted to have a large symptomatic patent ductus arteriosus with reversal of diastolic flow in the superior mesenteric vessels. Treatment with indomethacin led to ductal closure and concomitant restoration of diastolic flow and resolution of symptoms. Doppler studies of systemic vessels may help improve our understanding of the systemic impact of a haemodynamically significant ductus arteriosus.

Adverse drug reactions in newborns, infants and toddlers: pediatric pharmacovigilance between present and future

INTRODUCTION

The detection, assessment, understanding and prevention of adverse drug reactions (ADRs) are the primary aims of pharmacovigilance activities. Pediatric patients, especially all newborns and infants, are particularly at risk for experiencing drug-related adverse events.

AREAS COVERED

This review briefly analyzes the physiological peculiarities of pharmacodynamic and pharmacokinetic aspects of drugs in newborns, infants and toddlers and children. It also deals with specific pediatric pharmacovigilance aspects, such as the frequent use of unlicensed and/or off-label drugs in neonatal intensive care units in European countries and in Australia. This review reports on European, American and Canadian data about the incidence and type of pediatric ADRs, particularly focusing on neonates, infants and toddlers.

EXPERT OPINION

The awareness of pediatricians about the importance of reporting ADRs should be stimulated, new reporting systems should be encouraged and pediatric pharmacovigilance activities should be improved, first, by intensifying active post-marketing surveillance methods.

Change in blood pressure and pulse pressure in preterm infants after treatment of patent ductus arteriosus with indomethacin

Background and Objectives

Patent ductus arteriosus (PDA) is associated with increased morbidity and mortality in premature infants. Therefore, an early diagnosis and treatment of a hemodynamically significant PDA are very important. A widened pulse pressure is considered to be a well known clinical sign of a PDA in older infants and children; however, whether this is also applicable in the case of preterm infants remains to be confirmed. The aims of this study were to investigate the change in blood pressure (BP) before and after medical treatment of a PDA with indomethacin and to evaluate if the change in the pulse pressure in preterm infants with a medically treated PDA could be used as a reliable clinical predictor of a hemodynamically significant PDA.

Subjects and Methods

Between January 2005 and June 2009, a retrospective analysis was performed in preterm infants with a hemodynamically significant PDA (PDA group, n=72) and preterm infants without a PDA (control group, n=72) at the Chonnam National University Hospital Neonatal Intensive Care Unit. The PDA was closed by treatment with indomethacin. The BP was compared between the two groups over the seven days after the first dose of indomethacin.

Results

In preterm infants with a hemodynamically significant PDA, the mean systolic (55.1±6.0 mmHg) and diastolic BPs (31.4±6.2 mmHg) were lower than those in the controls (mean systolic BP 58.0±6.4 mmHg, mean diastolic BP 34.7±6.0 mmHg) before indomethacin treatment. When the ductus arteriosus was successfully closed by indomethacin treatment, there was a gradual increase in both the systolic and diastolic BPs without any change in the pulse pressure.

Conclusion

The results of this study show that a widened pulse pressure is not a useful clinical sign of a hemodynamically significant PDA in preterm infants. However, low systolic and diastolic BPs may be useful clinical signs of a hemodynamically significant PDA in preterm infants. If the systolic and diastolic BP is low, a PDA should be considered and echocardiography should be performed for early diagnosis and treatment.

Spectral Doppler waveforms in systemic arteries and physiological significance of a patent ductus arteriosus

Patent ductus arteriosus in extremely premature babies is associated with major neonatal morbidities, such as necrotizing enterocolitis and intraventricular hemorrhage. This may be attributable, at least in part, to systemic hypoperfusion secondary to ductal steal. A hemodynamically significant ductus arteriosus (HSDA) is known to be associated with altered systemic blood flow and end-organ hypoperfusion. Although descending aorta blood flow profiles may show abnormal diastolic retrograde flow, Doppler studies of blood flow in the systemic arteries may help improve our understanding of the relationship of a HSDA with these morbidities. In this article, we discuss aspects of diastolic blood flow reversal in the systemic arteries in premature infants with a hemodynamically significant duct. Whether these hemodynamic effects are significant enough to form the basis for initiating treatment is still unclear; these should form the basis for prospective studies.

Should we definitively abandon prophylaxis for patent ductus arteriosus in preterm new-borns?

Although the prophylactic administration of indomethacin in extremely low-birth weight infants reduces the frequency of patent ductus arteriosus and severe intraventricular hemorrhage, it does not appear to provide any long-term benefit in terms of survival without neurosensory and cognitive outcomes. Considering the increased drug-induced reduction in renal, intestinal, and cerebral blood flow, the use of prophylaxis cannot be routinely recommended in preterm neonates. However, a better understanding of the genetic background of each infant may allow for individualized prophylaxis using NSAIDs and metabolomics.

Acute lung injury in preterm newborn infants: mechanisms and management

Respiratory morbidity and mortality remain common in preterm infants. The immature preterm lung is especially prone to injury. This process often starts in-utero due to maternal chorioamnionitis, priming the lung for further injury in response to post-natal ventilation, oxygen and nosocomial infection. Pulmonary inflammation has been strongly implicated in the pathway leading to lung injury in this population of infants. Several therapeutic approaches have been attempted to prevent acute lung injury or to limit its progress. The mechanisms of acute lung injury in preterm infants; their clinical correlates and available therapeutic approaches are reviewed here.

Prophylactic intravenous indomethacin for preventing mortality and morbidity in preterm infants

BACKGROUND

Persistent patent ductus arteriosus (PDA) is associated with mortality and morbidity in preterm infants. Prostaglandin synthetase inhibitors such as indomethacin promote PDA closure but also have potential side effects. The effect of the prophylactic use of indomethacin, where infants who may not have gone on to develop a symptomatic PDA would be exposed to indomethacin, warrants particular scrutiny.

OBJECTIVES

To determine the effect of prophylactic indomethacin on mortality and morbidity in preterm infants.

SEARCH STRATEGY

The standard search strategy of the Cochrane Neonatal Review Group was used. This included searches of the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 5, 2010), MEDLINE, EMBASE and CINAHL (until April 2010), conference proceedings, and previous reviews.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials that compared prophylactic indomethacin versus placebo or no drug in preterm infants.

DATA COLLECTION AND ANALYSIS

The standard methods of the Cochrane Neonatal Review Group were used, with separate evaluation of trial quality and data extraction by two review authors.

MAIN RESULTS

Nineteen eligible trials in which 2872 infants participated were identified. Most participants were very low birth weight, but the largest single trial restricted participation to extremely low birth weight infants (N = 1202). The trials were generally of good quality.The incidence of symptomatic PDA [typical relative risk (RR) 0.44, 95% confidence interval (CI) 0.38 to 0.50] and PDA surgical ligation (typical RR 0.51, 95% CI 0.37,0.71) was significantly lower in treated infants. Prophylactic indomethacin also significantly reduced the incidence of severe intraventricular haemorrhage (typical RR 0.66, 95% CI 0.53 to 0.82). Meta-analyses found no evidence of an effect on mortality (typical RR 0.96, 95% CI 0.81 to 1.12) or on a composite of death or severe neurodevelopmental disability assessed at 18 to 36 months old (typical RR 1.02, 95% CI 0.90, 1.15).

AUTHORS' CONCLUSIONS

Prophylactic indomethacin has short-term benefits for preterm infants including a reduction in the incidence of symptomatic PDA, PDA surgical ligation, and severe intraventricular haemorrhage. However, there is no evidence of effect on mortality or neurodevelopment.

Therapeutic closure of the ductus arteriosus: benefits and limitations

Patency of the ductus arteriosus (PDA), a common complication of preterm birth, has been associated to increased risk for intraventricular cerebral hemorrhage, necrotizing enterocolitis, bronchopulmonary dysplasia and death. Consequently, prophylactic or curative treatment has been advocated before the critical left-to-right shunting occurs. A host of studies has shown that both pharmacological agents and surgical closure are effective in closing the ductus arteriosus in premature infants. Indomethacin has long been the drug of choice. However, renal and cerebral haemodynamic side effects have been frequently reported. Strategies to minimise adverse effects of indomethacin, such as the association with frusemide, dopamine or the use of low-dose prolonged treatment with indomethacin have failed or shown partial benefit. Other NSAIDs have been investigated. But either the profile of adverse effects was unfavourable, as in the case of mefenamic acid, or their efficacy was less than that of indomethacin for PDA closure. More recently, ibuprofen has been proposed for the treatment of PDA as it was shown to induce less adverse effects on cerebral blood flow, intestinal and renal hemodynamics, while retaining similar efficacy to indomethacin. However, since renal perfusion, GFR and diuresis in early neonatal life strongly depend on the vasodilator effects of PGs on the afferent glomerular arterioles, ibuprofen, as other COX-inhibitors may not be exempt of some renal undesirable effects. While numerous studies have shown that PDA is a risk factor associated with immaturity and with increased incidence of complications of preterm birth, including broncho-pulmonary dysplasia, retinopathy of prematurity, necrotizing enterocolitis and death, there is little evidence that such association is causative. Moreover, still little evidence exists from even recent randomized controlled trials that the pharmacological closure of PDA benefits to premature infants in terms of clinically significant short-term or medium-term outcomes, beyond a positive effect on DA patency. The use of COX-inhibitors for the prophylaxis or closure of PDA during the first hours or days of life should thus be cautious and based on an individual evaluation of benefit and risk. There is need of a randomized, placebo-controlled trials designed to assess the benefits in terms of mortality and morbidity outcomes of an early, or even very early pharmacological closure of PDA in extremely low gestational age infants.