Hemodynamic effects of fluid restriction in preterm infants with significant patent ductus arteriosus

Targeted Neonatal Echocardiography in the Management of Neonatal Pulmonary Hypertension

Pulmonary hypertension (PH) in neonates, originating from a range of disease states with heterogeneous underlying pathophysiology, is associated with significant morbidity and mortality. Although the final common pathway is a state of high right ventricular afterload leading to compromised cardiac output, multiple hemodynamic phenotypes exist in acute and chronic PH, for which cardiorespiratory treatment strategies differ. Comprehensive appraisal of pulmonary pressure, pulmonary vascular resistance, cardiac function, pulmonary and systemic blood flow, and extrapulmonary shunts facilitates delivery of individualized cardiovascular therapies in affected newborns.

Clinical and echocardiography predictors of response to first-line acetaminophen treatment in preterm infants with hemodynamically significant patent ductus arteriosus

OBJECTIVE

To assess clinical and echocardiography predictors of acetaminophen response for the treatment of patent ductus arteriosus (PDA) in preterm neonates.

STUDY DESIGN

Retrospective cohort study of preterm infants born <30 weeks, with a diagnosis of hemodynamically significant PDA, who received 1st line treatment with intravenous acetaminophen during the first 2 postnatal weeks. Response was defined by PDA closure or improvement in PDA score of >50%.

RESULTS

A total of 100 infants were included whose median weight and gestational age at birth were 663 grams and 24.6 weeks respectively. In total, 66 infants were classified as responders and were more likely to have intrauterine growth restriction, exposure to maternal hypertension and chorioamnionitis. Non-response was more common among infants with thrombocytopenia and anemia.

CONCLUSION

Responders were more likely to be IUGR with echocardiography indices of lower preload. Response to 1st line intravenous acetaminophen therapy is comparable to non-steroidal drugs in preterm infants. Relationship of response to acetaminophen to perinatal characteristics requires further characterization.

Should we "eliminate" PDA shunt in preterm infants? A narrative review

The patent ductus arteriosus frequently poses a significant morbidity in preterm infants, subjecting their immature pulmonary vascular bed to substantial volume overload. This, in turn, results in concurrent hypoperfusion to post-ductal organs, and subsequently alters cerebral blood flow. In addition, treatment has not demonstrated definitive improvements in patient outcomes. Currently, the optimal approach remains a subject of considerable debate with ongoing research controversy regarding the best approach. This article provides a comprehensive review of existing literature.

Closing the Gap: Investigation of Various Approaches in the Management of Patent Ductus Arteriosus

In preterm newborns with extremely low birth weights, patent ductus arteriosus (PDA), which is defined as a remnant connection between the aorta and pulmonary artery after 72 hours of birth, is frequently linked to substantial morbidity and mortality. If left untreated, a hemodynamically significant PDA (hsPDA) increases the risk for bronchopulmonary dysplasia, necrotizing enterocolitis, and intraventricular hemorrhage among other morbidities, and can even lead to death. While instances of patent ductus arteriosus (PDA) resolving on their own are frequent, the primary approach for managing PDA closure in premature infants involves pharmacological interventions, commonly utilizing indomethacin, ibuprofen, or paracetamol. However, with these pharmacological treatment options, there is an increased risk of renal toxicity, gastrointestinal bleeding, and reopening of PDA among other complications. If pharmacological interventions are not successful or contraindicated, PDA can be closed via transcatheter closure or surgical ligation. As with any medically invasive procedure, it is not without risks and can lead to long-term complications. This review explores the different management options and the benefits and outcomes of conservative management vs. active management in order to get one step closer to standardizing the treatment for PDA. With so much controversy surrounding the best management option, there is a lack of evidence to support one treatment method superior to the other in reducing overall mortality, and this needs to be explored further.

Nutrition of the preterm infant with persistent ductus arteriosus: existing evidence and practical implications

The persistence of a patent ductus arteriosus (PDA) is a common condition in preterm infants with a prevalence inversely proportional to gestational age. PDA is associated with mild-to-severe gastrointestinal complications such as feeding intolerance, gastrointestinal perforation, and necrotizing enterocolitis, which represent a major challenge for the nutritional management in preterm infants. In this context, the Section on Nutrition, Gastroenterology and Metabolism and the Circulation Section of the European Society for Pediatric Research have joined forces to review the current knowledge on nutritional issues related to PDA in preterm infants. The aim of the narrative review is to discuss the clinical implications for nutritional practice. Because there is little literature on postnatal nutrition and PDA in preterm infants, further research with well-designed studies on this topic is urgently needed. Guidelines should also be developed to clearly define the implementation and course of enteral nutrition and the target nutritional intake before, during, and after pharmacologic or surgical treatment of PDA, when indicated. IMPACT: Persistent ductus arteriosus (PDA) is associated with gastrointestinal complications such as feeding intolerance, gastrointestinal perforation, and necrotizing enterocolitis, which pose a major challenge to the nutritional management of preterm infants. In PDA infants, fluid restriction may lead to inadequate nutrient intake, which may negatively affect postnatal growth and long-term health. The presence of PDA does not appear to significantly affect mesenteric blood flow and splanchnic oxygenation after enteral feedings. Initiation or maintenance of enteral nutrition can be recommended in infants with PDA.

Hospital variation in neonatal echocardiography among very preterm infants at US children's hospitals

OBJECTIVE

Estimate hospital variation in echocardiography (echo) among very preterm infants.

STUDY DESIGN

Retrospective cohort study of very preterm (<32 weeks) infants discharged between 2012 and 2019 from US children's hospitals. Echo exposure was identified using daily billing, and hospital variation was estimated after adjustment for illness severity. Variation in very early echo use (<3 days of life) was compared to exposure to treatment of a patent ductus arteriosus (PDA), and other practice patterns.

RESULTS

27,498 subjects across 39 children's hospitals were included. Very early echo use had the greatest hospital variation (3-34%). Increasing very early echo use was not associated with PDA treatment (p = 0.93), but was associated with nitric oxide (p < 0.01) and vasoactive medications (p < 0.01).

CONCLUSIONS

Hospital variation in echo use among preterm infants was greatest in the first few days of life and was associated with increasing nitric oxide and vasoactive medication use. The impact of this variation on clinical outcomes is uncertain and warrants further investigation.

Fluid restriction in management of patent ductus arteriosus in Italy: a nationwide survey

We aimed at establishing the state of the art in fluid restriction practice in our national setting and providing a foundation for future research efforts. A prospective cross-sectional survey was conducted among all 114 Italian Neonatal Units in order to address conservative management of patent ductus arteriosus (PDA) in preterm infants below 29 weeks' gestational age (GA), with specific regard to fluid restriction. Response rate was 80%. Conservative measures for PDA management are provided in the majority of NICUs and 80% of centers reduce fluid intake in neonates with PDA. No relationship can be found among pharmacologically or surgically treated patients per year and the approach to fluid restriction. The minimum intake administered at regimen when fluid restriction is applied is associated to the ratio between the maximum number of neonates managed pharmacologically and number of admitted < 29 weeks' GA newborns.

CONCLUSION

Our survey shows an extreme variability among centers in terms of use of fluid restriction as a prophylactic tool but also in terms of its use (both opportunity and modality) when a hemodynamically significant PDA is diagnosed. This variability, that can be also found in randomized trials and observational studies, suggests that further evidence is needed to better understand its potential beneficial effects and its potential harms such as dehydration, hypotension, decreased end-organ perfusion, and reduced caloric intake.

WHAT IS KNOWN

• The lack of demonstrable improvement following the treatment of patent ductus arteriosus has recently paved the way to a more conservative approach. • Fluid restriction is the most commonly applied conservative treatment of PDA.

WHAT IS NEW

• Among Italian NICUs an extreme variability in terms of indications, timing and modalities of application of Fluid restriction can be found. • This variability reflects the lack of standardization of this practice and the contrasting evidence on its efficacy.

Fluid and electrolyte management in preterm infants with patent ductus arteriosus

Optimal fluid management of preterm babies with suspected or confirmed diagnosis of patent ductus arteriosus (PDA) is frequently challenging for neonatal care physician because of paucity of clinical trials. There is wide variation in practice across neonatal units, resulting in significant impact on outcomes in Extremely Low Birth Weight (ELBW) babies with hemodynamically significant PDA. A delicate balance is required in fluid management to reduce mortality and morbidity in this population. The purpose of this review is to lay out the current understanding about fluid and electrolyte management in ELBW babies with hemodynamically significant PDA and highlight areas for future research.

The role of furosemide and fluid management for a hemodynamically significant patent ductus arteriosus in premature infants

A patent ductus arteriosus (PDA) in infants born premature can present significant management challenges for neonatal providers. Quantifying a hemodynamically significant PDA (hsPDA) represents the first hurdle, however, identifying the best evidence-based approach amongst conservative, pharmacologic, and/or interventional management options has proven to be even more complicated. Within the conservative arm, furosemide to reduce pulmonary edema and improve lung function has spawned several discussions given the concerns for its upregulation of prostaglandin E₂ in the kidneys and conflicting outcomes data. There remains no consensus regarding furosemide use in hsPDAs. In this perspective article, we summarize the approach to defining a hsPDA, review the current practice of furosemide use in the management of hsPDA, and suggest an approach to fluid management and diuresis to address the question: is the routine use of furosemide in hsPDA merited in current practice?

Fresh Frozen Plasma Transfusion: An Independent Risk Factor for Hemodynamically Significant Patent Ductus Arteriosus in Premature Infants

OBJECTIVE

The incidence of patent ductus arteriosus (PDA), a major complication of prematurity, may be reduced by restricting fluid administration. Prophylactic fresh frozen plasma (FFP) transfusion may reduce the incidence of intraventricular hemorrhage in these infants, but risks transfusion-related volume overload. We conducted a retrospective study to investigate whether FFP transfusion is a risk factor for hemodynamically significant PDA (hsPDA) in very low birth weight (BW) premature infants.

STUDY DESIGN

From January 2009 to December 2014, 102 premature infants with gestational age (GA) less than or equal to 30 weeks were admitted to a level III neonatal intensive care unit, and 88 patients were enrolled. Patients were further divided into non-hsPDA (n = 29) and hsPDA groups (n = 59). We retrospectively reviewed demographic characteristics and various perinatal and postnatal variables. Univariate and multivariable analyses were performed to identify risk factors for hsPDA.

RESULTS

Compared with non-hsPDA patients, hsPDA patients had lower mean BW and GA, a higher incidence of severe respiratory distress symptoms, perinatal infection, use of surfactant, and need for FFP transfusion. However, multivariable logistic regression analysis showed that only FFP transfusion remained an independent risk factor for hsPDA (adjusted odds ratio = 3.880, 95% confidence interval: 1.214-12.402, p = 0.022) after adjusting for confounding factors.

CONCLUSION

FFP transfusion is a significant risk factor for the subsequent development of hsPDA in our study population. FFP transfusion may complicate the fluid management of premature infants and increase the risk of hsPDA.

KEY POINTS

· Hemodynamic significant PDA is an important complication of preterm infant.. · FFP transfusion may complicate the fluid management of premature infants.. · FFP transfusion is an independent risk factor for hsPDA in very low birth weight premature infants..

Oral versus intravenous paracetamol for patent ductus arteriosus closure in preterm infants

BACKGROUND

To examine whether oral administration of paracetamol as a first-line agent had a greater effect on the closure of a patent ductus arteriosus than the intravenous route.

METHODS

We performed a retrospective study of preterm infants (<37 weeks of gestation) between 2012 and 2020 treated with oral or intravenous paracetamol as the first line for patent ductus arteriosus (PDA) constriction and compared rates of ductal closure, course duration, cumulative dose, PDA characteristics, and serum levels.

RESULTS

Over the study period, 80 preterm infants received paracetamol, of which 50 received paracetamol as first-line treatment to augment constriction of the PDA. Closure rate was higher in the oral group (n = 15/19, 79%) compared to the intravenous group (n = 8/20, 40%, p < 0.01), and remained significant after adjusting for gestational age, length of treatment, and postnatal age (OR 0.14, 95% CI 0.03-0.67, p = 0.014, RR 0.51, 95% CI 0.28-0.91). Eleven preterm infants received a combination of both oral and intravenous paracetamol with a closure rate of 45% (n = 5).

CONCLUSIONS

Oral administration of paracetamol as a first-line agent is more efficacious to constrict the PDA than the intravenous route, irrespective of gestational age or course duration.

IMPACT

Our retrospective study comparing the use of oral versus intravenous paracetamol as the first line for patent ductus arteriosus (PDA) constriction in preterm infants demonstrates that oral administration of paracetamol is more efficacious to constrict the PDA than the intravenous route, irrespective of gestational age or course duration. To our knowledge, this is the first published study (prospective or retrospective) to compare the efficacy of oral versus intravenous paracetamol as a first-line treatment for PDA closure in preterm infants. Our finding may improve the rate of PDA closure when paracetamol is used as a first-line agent.

Weight gain in the first week of life and its association with morbidity and mortality in extremely low birthweight (ELBW) infants

BACKGROUND

Weight gain in the first week of life is indicative of fluid excess in preterm neonates.

AIMS

To determine if morbidity and/or mortality of extremely low birthweight (ELBW) infants was lower in those who did not have excess weight gain in the first week of life, compared with those who did.

STUDY DESIGN

Retrospective cohort study.

SUBJECTS

ELBW infants born from 1st May 2014 - 31st May 2019.

EXCLUSIONS

major congenital abnormalities (including hydrops), died within the first 7 days, no recorded weight on day 6, 7 or 8.

OUTCOME MEASURES

We compared infants whose weight was greater than birthweight by day 7 and infants whose weight remained at, or below, birthweight by day 7.

RESULTS

There were 312 ELBW infants in the study population: 15 (5%) died before discharge from hospital. Holding birthweight and gestational age (GA) constant, the odds of death in neonates with day 7 weight >birthweight was about 3 times the odds of death in neonates with day 7 weight ≤birthweight (adjusted odds ratio 3.18, 95% confidence interval 0.66-15.26, p = 0.15). Neonates with day 7 weight >birthweight were more likely to have had a PDA that required treatment than those with day 7 weight ≤birthweight (65% versus 43% respectively; p <0.001).

CONCLUSIONS

ELBW infants who gain weight in the first week of postnatal life, have a greater risk of PDA requiring treatment and may have a higher risk of mortality than infants who lose weight in the first week of life.

Patent ductus arteriosus management and the drift towards therapeutic nihilism - What is the evidence?

The published literature on patent ductus arteriosus (PDA) management is challenging to interpret due to poorly designed trials with high rates of open label treatments, homogenisation of patients with varying physiological subtypes, poor treatment efficacy, and spontaneous closure in more mature infants. The perceived lack of clinical benefit has led to a drift away from medical and surgical treatment of all infants with a PDA. This therapeutic nihilism as a default response to PDA management fails to recognise the physiological relevance of a left-to-right shunt with early haemodynamic instability after birth and subsequent pulmonary volume overload with prolonged exposure. Clinicians need to know if therapeutic nihilism is safe. This review will provide an overview of the available data on the efficacy of known PDA treatments, conservative management and supportive care measures that are currently applied.

Superior vena cava flow: Role, assessment and controversies in the management of perinatal perfusion

The superior vena cava (SVC) is a large vein responsible for the venous return of blood from structures located superior to the diaphragm. The flow in the SVC can be assessed with Doppler ultrasound and can be used as a proxy for cerebral perfusion. Early clinical research studies showed that low SVC flow, particularly if for a prolonged period, was associated with short term morbidity such as intraventricular hemorrhage, mortality, and poorer neurodevelopmental outcomes. However, these findings have not been consistently reported in more recent studies, and the role of SVC flow in early management and as a predictor of poor long-term neurodevelopment has been questioned. This paper provides an overview of SVC assessment, the expected range of findings, and reviews the role of SVC flow as a diagnostic and monitoring tool for the assessment of perinatal perfusion.

Molecular and Mechanical Mechanisms Regulating Ductus Arteriosus Closure in Preterm Infants

Failure of ductus arteriosus closure after preterm birth is associated with significant morbidities. Ductal closure requires and is regulated by a complex interplay of molecular and mechanical mechanisms with underlying genetic factors. In utero patency of the ductus is maintained by low oxygen tension, high levels of prostaglandins, nitric oxide and carbon monoxide. After birth, ductal closure occurs first by functional closure, followed by anatomical remodeling. High oxygen tension and decreased prostaglandin levels mediated by numerous factors including potassium channels, endothelin-1, isoprostanes lead to the contraction of the ductus. Bradykinin and corticosteroids also induce ductal constriction by attenuating the sensitivity of the ductus to PGE2. Smooth muscle cells of the ductus can sense oxygen through a mitochondrial network by the role of Rho-kinase pathway which ends up with increased intracellular calcium levels and contraction of myosin light chains. Anatomical closure of the ductus is also complex with various mechanisms such as migration and proliferation of smooth muscle cells, extracellular matrix production, endothelial cell proliferation which mediate cushion formation with the interaction of blood cells. Regulation of vessel walls is affected by retinoic acid, TGF-β1, notch signaling, hyaluronan, fibronectin, chondroitin sulfate, elastin, and vascular endothelial cell growth factor (VEGF). Formation of the platelet plug facilitates luminal remodeling by the obstruction of the constricted ductal lumen. Vasa vasorum are more pronounced in the term ductus but are less active in the preterm ductus. More than 100 genes are effective in the prostaglandin pathway or in vascular smooth muscle development and structure may affect the patency of ductus. Hemodynamic changes after birth including fluid load and flow characteristics as well as shear forces within the ductus also stimulate closure. Current pharmacological treatment for the closure of a patent ductus is based on the blockage of the prostaglandin pathway mainly through COX or POX inhibition, albeit with some limitations and side effects. Further research for new agents aiming ductal closure should focus on a clear understanding of vascular biology of the ductus.

Survey of PDA management in very low birth weight infants across Italy

Background

The optimal management of PDA in very low birth weight (VLBW) infants is still controversial. Aim of our study was to investigate the management of PDA in the Italian neonatal intensive care units (NICU).

Methods

We conducted an on-line survey study from June to September 2017. A 50-items questionnaire was developed by the Italian Neonatal Cardiology Study Group and was sent to Italian NICUs.

Results

The overall response rate was 72%. Diagnosis of PDA was done by neonatologists, cardiologists or both (62, 12 and 28% respectively). PDA significance was assessed by a comprehensive approach in all centers, although we found a heterogeneous combination of parameters and cut-offs used. None used prophylactic treatment. 19% of centers treated PDA in the first 24 h, 60% after the first 24 h, following screening echocardiography or clinical symptoms, 18% after the first 72 h and 2% after the first week. In the first course of treatment ibuprofen, indomethacin and paracetamol were used in 87, 6 and 7% of centers respectively. Median of surgical ligation was 3% (1–6%).

Conclusions

Significant variations exist in the management of PDA in Italy. Conservative strategy and targeted treatment to infants older than 24 h with echocardiographic signs of hemodynamic significance seemed to be the most adopted approach.

Fluid restriction negatively affects energy intake and growth in very low birthweight infants with haemodynamically significant patent ductus arteriosus

AIM

We explored if fluid restriction in very low birthweight (VLBW) infants with a haemodynamically significant patent ductus arteriosus (PDA) affected energy and protein intakes and growth.

METHODS

Retrospectively, we identified 90 VLBW infants that were admitted to Umea University Hospital, Sweden, between 2009 and 2012: 42 with and 48 without haemodynamically significant PDA (hsPDA). Anthropometric, fluid, energy and protein intake data during the first 28 days of life were expressed as z-scores.

RESULTS

In the 42 infants diagnosed with hsPDA, fluid intake was restricted after diagnosis, resulting in a decrease in energy and protein intake. No decrease was observed in the other 48 infants in the cohort. Multivariate analysis showed that the z-score of weight change depended on both ductus arteriosus status and energy intake; thus, infants with hsPDA did not grow as expected with the energy provided to them.

CONCLUSION

Energy and protein intake was diminished in prematurely born infants with hsPDA when fluid was restricted after diagnosis. The initial reduction in intakes may have contributed to the lower postnatal growth observed in these infants.

Surgical management of a patent ductus arteriosus: Is this still an option?

The evolution of neonatal intensive care over the past decade has seen the role of surgical patent ductus arteriosus (PDA) ligation in preterm infants both decrease in scope and become laden with uncertainty. Associations of ligation with adverse neonatal and neurodevelopmental outcomes have rendered the ligation decision more challenging for clinicians and have been associated with a decline in surgical treatment, but these findings may be due to bias from confounding by indication in observational studies rather than a causal detrimental effect of ligation. Accordingly, ligation may still be indicated for infants with large ductal shunts and moderate-severe respiratory insufficiency in whom the prospect of timely spontaneous closure appears low. Ultimately a randomized trial of surgical ligation versus conservative management is necessary to assess the efficacy of this invasive intervention in a population of extremely preterm infants with large ductal shunts. Simultaneously, the transcatheter approach to ductal closure in the very immature infant represents an exciting therapeutic alternative but which is still in its infancy. Insights into the pathophysiology of postoperative cardiorespiratory deterioration, including the importance of left ventricular afterload, may help clinicians avoid instability and mitigate a potentially injurious aspect of surgical treatment. This review examines the evidence regarding the benefits and risks of PDA surgery in preterm neonates and provides a pathophysiology-based management paradigm to guide perioperative care in high-risk infants.

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.

Non-pharmacological management of a hemodynamically significant patent ductus arteriosus

The association between the patent ductus arteriosus (PDA) and neonatal morbidity, mortality and poor neurodevelopmental outcome in later childhood has been the focus of intense debate for decades. The lack of evidence supporting therapeutic strategies aimed at achieving PDA closure has led to the widespread adoption of conservative management aimed at mitigating the impact of shunt volume without achieving ductal closure. In this article, we review this management approach, describe the supportive evidence and potential complications associated with this strategy.

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.

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.

Trends in Patent Ductus Arteriosus Diagnosis and Management for Very Low Birth Weight Infants

OBJECTIVE

To examine yearly trends of patent ductus arteriosus (PDA) diagnosis and treatment in very low birth weight infants.

METHODS

In this retrospective cohort study of very low birth weight infants (<1500 g) between 2008 and 2014 across 134 California hospitals, we evaluated PDA diagnosis and treatment by year of birth. Infants were either inborn or transferred in within 2 days after delivery and had no congenital abnormalities. Intervention levels for treatment administered to achieve ductal closure were categorized as none, pharmacologic (indomethacin or ibuprofen), both pharmacologic intervention and surgical ligation, or ligation only. Multivariable logistic regression was used to assess risk factors for PDA diagnosis and treatment.

RESULTS

PDA was diagnosed in 42.8% (12 002/28 025) of infants, with a decrease in incidence from 49.2% of 4205 infants born in 2008 to 38.5% of 4001 infants born in 2014. Pharmacologic and/or surgical treatment was given to 30.5% of patients. Between 2008 and 2014, the annual rate of infants who received pharmacologic intervention (30.5% vs 15.7%) or both pharmacologic intervention and surgical ligation (6.9% vs 2.9%) decreased whereas infants who were not treated (60.5% vs 78.3%) or received primary ligation (2.2% vs 3.0%) increased.

CONCLUSIONS

There is an increasing trend toward not treating patients diagnosed with PDA compared with more intensive treatments: pharmacologic intervention or both pharmacologic intervention and surgical ligation. Possible directions for future study include the impact of these trends on hospital-based and long-term outcomes.

Patent Ductus Arteriosus in the Preterm Infant: Diagnostic and Treatment Options

BACKGROUND

The incidence of hemodynamically significant patent ductus arteriosus (hsPDA) increases with decreasing gestational age and is associated with many common morbidities of extreme prematurity. Controversies remain surrounding the definition of hsPDA, the population of infants requiring treatment, the appropriate timing and method of treatment, and the outcomes associated with PDA and its therapies.

PURPOSE

This integrative literature review focuses on diagnostic and treatment recommendations derived from the highest levels of evidence.

SEARCH STRATEGY

PubMed and CINAHL were searched using key words "neonatal" and "patent ductus arteriosus" to discover the highest levels of evidence surrounding diagnosis, treatment methods, and outcomes.

FINDINGS/RESULTS

The lack of consensus surrounding the diagnosis and clinical significance of PDA hinders meta-analysis across studies and confounds understanding of appropriate management strategies. Novel biomarkers, pharmaceutical choices, and transcatheter closure methods are expanding diagnostic and treatment options.

IMPLICATIONS FOR PRACTICE

Infants weighing less than 1000 g are at highest risk. Prophylactic closure is no longer recommended, although early asymptomatic therapy is still preferred by some to avoid prolonged pulmonary overcirculation or decreased renal and gut perfusion. Conservative treatment measures such as fluid restriction and diuretic administration have not consistently proven effective and are in some instances detrimental. Cyclooxygenase inhibitors are effective but have adverse renal and mesenteric effects. Oral ibuprofen is associated with lower instance of necrotizing enterocolitis.

IMPLICATIONS FOR RESEARCH

Well-defined staging criteria would aid in comparison and meta-analysis. Trials that include a control group that receives no therapy may help separate the outcomes associated with prematurity from those associated with PDA.

[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.

Acetaminophen to avoid surgical ligation in extremely low gestational age neonates with persistent hemodynamically significant patent ductus arteriosus

OBJECTIVE

The objective of this study was to evaluate the effectiveness of rescue oral acetaminophen in improving echocardiography (echo) indices of patent ductus arteriosus (PDA) shunt volume and avoiding surgical ligation in extremely low gestational age (GA) neonates (ELGANs, <28 weeks) with persistent PDA.

STUDY DESIGN

Retrospective cohort study of ELGANs with moderate or severe PDA at risk for ligation after a practice change introducing oral acetaminophen (60 mg kg(-1) day(-1) for 3 to 7 days) to facilitate ductal constriction after indomethacin failure.

RESULTS

Twenty-six infants (median GA 24.4 weeks at birth) with persistent PDA under consideration for surgical ligation were treated with oral acetaminophen at a mean of 27 days of life. Echo indices of shunt volume improved in 12 (46%) infants (3 closed and 9 reduced to mild shunt), all of whom avoided ligation. There was no echo improvement in 14 (54%) infants, of which 8/14 underwent ligation, and ligation was deferred in 6/14 infants, mostly owing to improvement in respiratory stability. Fewer responders than non-responders underwent ligation (0% vs 57%, P<0.01), though there were no differences in other neonatal outcomes.

CONCLUSIONS

In ELGANs with persistent significant PDA, rescue therapy with oral acetaminophen was associated with improvement in echo indices of shunt volume and avoidance of ligation in nearly half of infants.

Patent ductus arteriosus in preterm infants: do we have the right answers?

Patent ductus arteriosus (PDA) is a common clinical condition in preterm infants. Preterm newborns with PDA are at greater risk for several morbidities, including higher rates of bronchopulmonary dysplasia (BPD), decreased perfusion of vital organs, and mortality. Therefore, cyclooxygenase (COX) inhibitors and surgical interventions for ligation of PDA are widely used. However, these interventions were reported to be associated with side effects. In the absence of clear restricted rules for application of these interventions, different strategies are adopted by neonatologists. Three different approaches have been investigated including prophylactic treatment shortly after birth irrespective of the state of PDA, presymptomatic treatment using echocardiography at variable postnatal ages to select infants for treatment prior to the duct becoming clinically significant, and symptomatic treatment once PDA becomes clinically apparent or hemodynamically significant. Future appropriately designed randomized controlled trials (RCTs) to refine selection of patients for medical and surgical treatments should be conducted. Waiting for new evidence, it seems wise to employ available clinical and echocardiographic parameters of a hemodynamically significant (HS) PDA to select patients who are candidates for medical treatment. Surgical ligation of PDA could be used as a back-up tool for those patients who failed medical treatment and continued to have hemodynamic compromise.

Management of patent ductus arteriosus in preterm infants--where do we stand?

Patent ductus arteriosus (PDA) in preterm infants is a controversial topic in the management of preterm neonates. There are no generally accepted guidelines for diagnosis, treatment, and follow-up of PDA, and few publications have covered the whole topic or have been conclusively summarized to give a proper direction for the treating physician. Major issues remain to be clarified, both with respect to diagnosis and treatment. The definition of hemodynamic significance varies because of different use of echocardiographic criteria and uncertainty about the role of biomarkers. The detailed risks and benefits of available treatment alternatives are still under investigation. There has been a general shift in the management of PDA in preterm neonates from the "aggressive approach" to a more "conservative approach," but the effects of this strategy on morbidity in a longer time perspective are not fully known. An individualized therapeutic strategy with special emphasis on identification of hemodynamically significance seems to be the way forward. In this review we put forward the scientific background in favor of a seemingly growing body of evidence against active treatment, but we raise caution against shying away from all forms of treatment or instituting them too late. Finally, we try to integrate the current knowledge into suggestions for the management of PDA in premature infants.