Prolonged persistent patent ductus arteriosus: potential perdurable anomalies in premature infants

Combination pharmacotherapy for patent ductus arteriosus: Rationale and evidence

While cyclooxygenase inhibitors have been the most common medications used to facilitate earlier closure of patent ductus arteriosus in preterm infants, adverse effects and low efficacy in extremely low gestational age neonates (ELGANs) have highlighted a need for alternative options. Combination therapy with acetaminophen and ibuprofen is a novel strategy for PDA treatment in ELGANs, as it may facilitate higher ductal closure rates via additive action on two separate pathways inhibiting prostaglandin production. Initial small observational studies and pilot randomized clinical trials indicate potentially higher efficacy of the combination regime to induce ductal closure in comparison to treatment with ibuprofen alone. In this review, we examine the potential clinical impact of treatment failure in ELGANs with significant PDA, highlight the biological rationale in support of studying combination therapy, and review the randomized and non-randomized studies to date. With the rising number of ELGANs receiving neonatal intensive care, who are vulnerable to PDA-related morbidities, there is an urgent need for adequately powered clinical trials to systematically investigate the efficacy and safety of combination therapy for PDA treatment.

Extremely premature infants with patent ductus arteriosus closure: Comparative analysis of surgical ligation versus cardiac catheterization-based closure

ABSTRACT

Our objective was to compare postprocedure hemodynamic decompensation in extremely premature infants who had their patent ductus arteriosus (PDA) closed with surgical ligation (SL) versus cardiac catheter-based closure (CCC).This is a single-center retrospective review of extremely premature ( < 28 weeks) infants who had their PDA closed by SL or CCC.Of the total of 69 infants, 53 underwent SL, and 16 had CCC. Infants in 2 groups were comparable at birth. However, at the time of the procedure, infants in the SL group were smaller, less mature, and had higher respiratory support. Vasopressor use, both pre- and postprocedure, was more common in the SL group. Nineteen percent of the infants in the SL group, compared to 6% in the CCC group (P = .34), required dose escalation or use of vasopressors after the PDA closure.There was no significant difference between the 2 groups in postoperative hemodynamic decompensation. Large, multicenter, prospective study or randomized control trial will help to confirm our findings.

Oral Versus Intravenous Medications for Treatment of Patent Ductus Arteriosus in Preterm Neonates: A Cost-Saving Initiative

OBJECTIVE

The purpose of the study was to quantify cost savings after promoting oral pharmacotherapy for the treatment of hemodynamically significant patent ductus arteriosus (hsPDA).

METHODS

This was a retrospective before-and-after time series quality improvement study. Oral ibuprofen and acetaminophen use criteria were developed and recommended, rather than the more costly intravenous equivalents. There were 24-month medication use reports generated for both the pre-criteria (Era-1) and the post-criteria (Era-2) implementation phases to identify neonates prescribed hsPDA medications in order to assess cost differences.

RESULTS

Era-1 had 190 treatment courses in 110 neonates for a total medication cost of $171,260.70. Era-2 had 210 courses in 109 patients for a total medication cost of $47,461.49, yielding savings of $123,799.21 ($61,899.61 annually) after criteria implementation. The reduction in intravenous ibuprofen use in Era-2 accounted for all the savings.

CONCLUSION

Preferentially prescribing lower-cost oral medications to treat hsPDA led to significant cost savings.

Bedside cardiopulmonary ultrasonography evaluates lung water content in very low-weight preterm neonates with patent ductus arteriosus

BACKGROUND

Patent ductus arteriosus (PDA) is a common congenital heart abnormality in preterm neonates with a high incidence in neonates with very low birth weights. When PDA persists, interstitial lung water content increases, which could lead to abnormal circulation hemodynamics and pulmonary edema. It is important to perform early and reliable assessment of lung water content in very low-weight preterm neonates with persistent PDA.

AIM

To evaluate the role of bedside cardiopulmonary ultrasonography in the lung water content assessment in very low-weight preterm neonates with persistent PDA.

METHODS

From January 2018 to March 2020, 69 very low-weight preterm neonates with echocardiography-confirmed PDA were selected as the PDA group. At the same time, 89 very low-weight preterm neonates without PDA were randomly selected as the control group. All neonates underwent echocardiography and 6-segment lung ultrasonography on the fourth day after birth. The clinical characteristics and main ultrasonography results were compared between the two groups. Pearson's analysis was used to analyze the correlation between lung ultrasonography score (LUS) and other related clinical and ultrasonography results in all neonates. In the PDA group, PDA diameters were recorded, and the correlation with LUS and left atrium to aortic (LA/AO) dimension ratio were also analyzed. LA/AO ratio is one of the ultrasonic diagnostic criteria for hemodynamically significant PDA. When the ratio is ≥ 1.5, it suggests the possibility of hemodynamic changes in persistent PDA. A receiver operating characteristic curve was established using the sensitivity of LUS to predict the hemodynamic changes in neonates with PDA as the ordinate and 1-specificity as the abscissa.

RESULTS

A total of 158 neonates were enrolled in this study, including 69 in the PDA group and 89 in the control group. There were no statistical differences in sex, gestational age, birth weight, ventilator dependence, hospitalization length and left ventricular ejection fraction between the two groups (P > 0.05). The LUS and LA/AO ratio in the PDA group were higher than those in the control group (P < 0.05), but there was no difference of LUS in neonates with or without use of the ventilator (t = 0.58, P = 0.16). In all cases, LUS was negatively correlated with gestational age (r = -0.28, P < 0.01) and birth weight (r = -0.36, P < 0.01), while positively correlated with the LA/AO ratio (r = 0.27, P < 0.01). In the PDA group, PDA diameter was positively correlated with the LA/AO ratio (r = 0.39, P < 0.01) and LUS (r = 0.31, P < 0.01). Receiver operating characteristic results showed that LUS had the moderate accuracy for predicting hemodynamic changes in PDA (area under the curve = 0.741; sensitivity = 93.75%; specificity = 50.94%).

CONCLUSION

Bedside cardiopulmonary ultrasonography can evaluate lung content in neonates with PDA and predict the possibility of hemodynamic changes in persistent PDA.

Interventions on patent ductus arteriosus and its impact on congenital heart disease

The ductus arteriosus (DA) connects the pulmonary artery to the aorta to bypass the pulmonary circulation in utero. It normally closes within 24-72 hours after birth due to increased pulmonary resistance from an increase in oxygen partial pressure with the baby's first breath. Medical treatment can help close the DA in certain situations where closure is delayed. However, in duct-dependent cardiac defects, the presence of the DA is crucial for survival and as such medical and surgical techniques have evolved to prevent closure. This review aims to outline the two main management options for keeping a ductus arteriosus patent. This includes stenting the PDA and shunting via a modified Blalock-Taussig shunt. Whilst both techniques exist, multicentre trials have found equal mortality end points but significantly reduced morbidity with stenting than shunting. This is also reflected by shorter recovery times, reduced requirement for extracorporeal membrane oxygenation (ECMO), and improved quality of life, although stent longevity remains a limiting factor.

Patent Ductus Arteriosus of the Preterm Infant

Postnatal ductal closure is stimulated by rising oxygen tension and withdrawal of vasodilatory mediators (prostaglandins, nitric oxide, adenosine) and by vasoconstrictors (endothelin-1, catecholamines, contractile prostanoids), ion channels, calcium flux, platelets, morphologic maturity, and a favorable genetic predisposition. A persistently patent ductus arteriosus (PDA) in preterm infants can have clinical consequences. Decreasing pulmonary vascular resistance, especially in extremely low gestational age newborns, increases left-to-right shunting through the ductus and increases pulmonary blood flow further, leading to interstitial pulmonary edema and volume load to the left heart. Potential consequences of left-to-right shunting via a hemodynamically significant patent ductus arteriosus (hsPDA) include increased risk for prolonged ventilation, bronchopulmonary dysplasia, necrotizing enterocolitis or focal intestinal perforation, intraventricular hemorrhage, and death. In the last decade, there has been a trend toward less aggressive treatment of PDA in preterm infants. However, there is a subgroup of infants who will likely benefit from intervention, be it pharmacologic, interventional, or surgical: (1) prophylactic intravenous indomethacin in highly selected extremely low gestational age newborns with PDA (<26 + 0/7 weeks' gestation, <750 g birth weight), (2) early targeted therapy of PDA in selected preterm infants at particular high risk for PDA-associated complications, and (3) PDA ligation, catheter intervention, or oral paracetamol may be considered as rescue options for hsPDA closure. The impact of catheter-based closure of hsPDA on clinical outcomes should be determined in future prospective studies. Finally, we provide a novel treatment algorithm for PDA in preterm infants that integrates the several treatment modalities in a staged approach.

Early NT-proBNP levels as a screening tool for the detection of hemodynamically significant patent ductus arteriosus during the first week of life in very low birth weight infants

OBJECTIVE

To assess whether early NT-ProBNP can identify the need for echocardiographic assessment of hemodynamically significant patent ductus arteriosus (HsPDA) in preterm infants.

STUDY DESIGN

Prospective observational study of infants with a gestational age ≤32 weeks. Echocardiographic assessment and NT-proBNP measurement were performed at 48-96 h. ROC curves were generated to assess optimal cutoffs to detect HsPDA and predict the need for treatment.

RESULTS

Eighty-five patients were included. HsPDA was present in 28 infants (37.6%), and 22 (25.8%) received treatment. The optimal NT-proBNP cutoff for the detection of HsPDA was 5099 pg/mL (sensitivity 94%, specificity 82%, area under the curve 0.941, P < 0.001). Only 1 child with NT-proBNP levels <5099 pg/mL was ultimately treated for PDA. NT-proBNP screening could have avoided 45 of 85 routine echocardiograms (53%).

CONCLUSION

NT-proBNP screening at 48-96 h of life may identify preterm infants at low risk for HsPDA, improving PDA management.

Reduced oxygen concentration for the resuscitation of infants with congenital diaphragmatic hernia

OBJECTIVE

To evaluate whether infants with congenital diaphragmatic hernia (CDH) can be safely resuscitated with a reduced starting fraction of inspired oxygen (FiO₂) of 0.5.

STUDY DESIGN

A retrospective cohort study comparing 68 patients resuscitated with starting FiO₂ 0.5 to 45 historical controls resuscitated with starting FiO₂ 1.0.

RESULTS

Reduced starting FiO₂ had no adverse effect upon survival, duration of intubation, need for ECMO, duration of ECMO, or time to surgery. Furthermore, it produced no increase in complications, adverse neurological events, or neurodevelopmental delay. The need to subsequently increase FiO₂ to 1.0 was associated with female sex, lower gestational age, liver up, lower lung volume-head circumference ratio, decreased survival, a higher incidence of ECMO, longer time to surgery, periventricular leukomalacia, and lower neurodevelopmental motor scores.

CONCLUSION

Starting FiO₂ 0.5 may be safe for the resuscitation of CDH infants. The need to increase FiO₂ to 1.0 during resuscitation is associated with worse outcomes.

Catheter-based closure of the patent ductus arteriosus in lower weight infants

Risks associated with drug therapy and surgical ligation have led health care providers to consider alternative strategies for patent ductus arteriosus (PDA) closure. Catheter-based PDA closure is the procedure of choice for ductal closure in adults, children, and infants ≥6kg. Given evidence among older counterparts, interest in catheter-based closure of the PDA in lower weight (<6kg) infants is growing. Among these smaller infants, the goals of this review are to: (1) provide an overview of the procedure; (2) review the types of PDA closure devices; (3) review the technical success (feasibility); (4) review the risks (safety profile); (5) discuss the quality of evidence on procedural efficacy; (6) consider areas for future research. The review provided herein suggests that catheter-based PDA closure is technically feasible, but the lack of comparative trials precludes determination of the optimal strategy for ductal closure in this subgroup of infants.

Relevance of clinical features in the prognosis of bronchopulmonary dysplasia in premature infants

The aim of this study is to determine the accuracy rate of bronchopulmonary dysplasia (BPD) diagnosis and risk factors of short-term poor prognosis for premature infants. This study analyzed the clinical data of 81 premature infants (<32 weeks gestational age) with BPD, who were on oxygen therapy >28 days, and survived >36 weeks (corrected age). Outcome measures included treatments, conditions on the 28th day after birth, oxygen therapy conditions at the 36th week, occurrence of any serious complications during hospital stay. The major risk factors affecting prognosis were ventilation duration, duration of oxygen therapy, application of steroids, hypothyroidism and severity of BPD (all P<0.05). Interventions for complications (n=53) resulted in ceased inhalation of oxygen in 12 infants, improvement of symptoms in 26 infants, and were ineffective in 15 infants. BPD prognosis can be improved by shortening the duration of invasive ventilation and correcting thyroid function.

Population based report on health related quality of life in adolescents born very preterm

BACKGROUND

As the survival rate of preterm infants constantly improves, knowledge on the impact of prematurity on long-term health-related quality of life (HRQoL) is important for clinical and parental guidance. We aimed to assess HRQoL in a national cohort of young adolescents born very preterm, and to identify predictors for poorer HRQoL.

PATIENTS AND METHODS

All surviving Swiss live-born children below 30weeks of gestation during the year 2000 (290 subjects) were contacted at age 12years, together with their parents (262 families). HRQoL of the study children was assessed using both the Kidscreen-27 (KS-27) self- and parent forms. Neonatal data of the cohort were prospectively collected.

RESULTS

Among the contacted families, 176 returned the complete set of questionnaires for 194 adolescents (67%): 100 (51%) females, mean (range) gestational age was 27.8 (24.1-29.9) weeks, birth weight 1025 (420-1730) grams, mean age at assessment 12.0 (11.0-13.0) years. Included children had similar neonatal and socio-demographic characteristics as non-responders. Average self- and parent-reported HRQoL of former preterms was similar to Swiss KS-27 norms. According to the multivariable models (r²=0.2), surgical closure of patent ductus arteriosus, attention deficit/hyperactivity disorder, severe neurodevelopment impairment were negatively associated with both self- and parent-reported HRQoL.

CONCLUSIONS

HRQoL in this population-based cohort of adolescents born very preterm is good. Surgical closure of patent ductus arteriosus, attention deficit/hyperactivity disorder, severe neurodevelopment impairment were identified as predictors of poorer HRQoL using multivariable models, explaining however only a low proportion of variance in HRQoL.

Transcatheter closure of PDA in premature babies less than 2 kg

Objective:

Our hypothesis was that percutaneous PDA closure in babies less than 2 kg was a safe and effective method. The aim of this study is to share our experience in transcatheter PDA closure in infants whose body weight is less than 2 kg in order to support our hypothesis.

Methods:

Between July 1997 and October 2014, 382 percutaneous PDA closures were done in our center. Nineteen patients who weighed less than 2 kg were included in this retrospectively study. The other inclusion criteria were 1) being symptomatic and PDA was thought as a possible contributor of medical state and 2) persistence of PDA after medical closure treatment. Patients who had sepsis and bleeding diathesis were excluded. According to size and shape of PDA, different types of devices were used such as detachable coils and Amplatzer duct occluders. Data was expressed as mean (SD) or median (minimum–maximum). Comparisons of means and medians were performed with Student’s t-test and with Mann–Whitney U test, respectively.

Results:

The median patient age and weight were 32 days and 1603 g (range 910–2000 g) respectively. Mean PDA diameter was 3.2±1.3 mm. Morphology of PDA was type A in 7 patients, type C in 10, type E in 1, and type B in 1 patient. There were no reported major complications. Stenosis of left pulmonary artery was detected in four patients, all of which resolved in 6 months follow-up.

Conclusion:

Percutaneous PDA closure in babies less than 2 kg is a safe and effective method that can be an alternative to surgery. Main distinguishing feature of this study is that it includes the largest cohort of patients less than 2 kg whose PDA closed percutaneously.

Paracetamol for the treatment of patent ductus arteriosus in preterm neonates: a systematic review and meta-analysis

OBJECTIVES

We performed a systematic review and meta-analysis of all the available evidence to assess the efficacy and safety of paracetamol for the treatment of patent ductus arteriosus (PDA) in neonates, and to explore the effects of clinical variables on the risk of closure.

DATA SOURCE

MEDLINE, Scopus and ISI Web of Knowledge databases, using the following medical subject headings and terms: paracetamol, acetaminophen and patent ductus arteriosus. Electronic and manual screening of conference abstracts from international meetings of relevant organisations. Manual search of the reference lists of all eligible articles.

STUDY SELECTION

Studies comparing paracetamol versus ibuprofen, indomethacin, placebo or no intervention for the treatment of PDA.

DATA EXTRACTION

Data regarding efficacy and safety were collected and analysed.

RESULTS

Sixteen studies were included: 2 randomised controlled trials (RCTs) and 14 uncontrolled studies. Quality of selected studies is poor. A meta-analysis of RCTs does not demonstrate any difference in the risk of ductal closure (Mantel-Haenszel model, RR 1.07, 95% CI 0.87 to 1.33 and RR 1.03, 95% CI 0.92 to 1.16, after 3 and 6 days of treatment, respectively). Proportion meta-analysis of uncontrolled studies demonstrates a pooled ductal closure rate of 49% (95% CI 29% to 69%) and 76% (95% CI 61% to 88%) after 3 and 6 days of treatment with paracetamol, respectively. Safety profiles of paracetamol and ibuprofen are similar.

CONCLUSIONS

Efficacy and safety of paracetamol appear to be comparable with those of ibuprofen. These results should be interpreted with caution, taking into account the non-optimal quality of the studies analysed and the limited number of neonates treated with paracetamol so far.

Retinopathy of prematurity: Risk factors and variability in Canadian neonatal intensive care units

OBJECTIVE

To identify predictors of severe retinopathy of prematurity (ROP) in a large population-based cohort and to examine risk-adjusted variations across units.

STUDY DESIGN

Retrospective analysis of Canadian Neonatal Network data on neonates with birth weight <1500 g who were screened for ROP between 2003 and 2010. Characteristics of infants with and without ROP were compared and a risk-adjusted model for severe ROP was developed. Rates of severe ROP were compared between sites.

RESULTS

1163 of 9187 (12.7%) infants developed severe ROP. Lower gestational age, male sex, small for gestational age, patent ductus arteriosus, late onset sepsis, more than two blood transfusions, inotrope use, and outborn status were associated with an increased risk of severe ROP. Severe ROP rates varied significantly between units.

CONCLUSION

Younger, smaller and sicker male infants had higher adjusted risks of severe ROP and rates varied significantly among sites.

Management of patent ductus arteriosus in premature infants

Patency of the ductus arteriosus is required for fetal survival in utero. In infants born prematurely, ductus fails to close and shunt reverses from left to right. Incidence of patent ductus arteriosus (PDA) is inversely proportional to the gestational age. A large PDA (>1.5 mm diameter) with left to right shunt in very low birth weight infants can cause pulmonary edema, congestive heart failure, pulmonary hemorrhage and increase the risk for bronchopulmonary dysplasia. Attempts to prevent or close the duct by pharmacological or surgical methods have not changed the morbidity or the long term outcome. Pharmacological treatment with indomethacin or ibuprofen is successful in 75 to 80 % of infants but its use also exposes these infants to undesirable side effects like gastrointestinal bleeding, perforation and necrotizing enterocolitis. Prophylactic therapy with indomethacin or ibuprofen to prevent PDA has not altered the morbidity or long term outcome. Currently, there is a dilemma as to how to treat, when to treat and whom to treat. Recent literature suggests a trial of conservative management during the first week followed by selective use of anti-inflammatory drugs. Surgical ligation is reserved for infants who fail medical therapy and still remain symptomatic. Spontaneous closure of the PDA has been reported in up to 40-67 % of very low birth weight (VLBW) infants by 7 d. In this review authors discuss these controversies and propose a more rational approach.

Paracetamol to induce ductus arteriosus closure: is it valid?

There remains a need for alternative medical treatments for patent ductus arteriosus (PDA) closure in extreme preterm neonates because of therapeutic failure and adverse effects associated with non-selective cyclo-oxygenase inhibitors. Reports of an association between paracetamol exposure and PDA closure in a limited number of extreme preterm neonates have been published. However, causality cannot be taken for granted because a link between the current knowledge of the clinical pharmacology of paracetamol and (patho)physiology of ductal closure is not known. In contrast to non-selective cyclo-oxygenase inhibitors, paracetamol has limited effects at peripheral sites, is a poor antithrombotic and anti-inflammatory drug and exerts its effects primarily within the central nervous system. Although paracetamol appears an effective and safe analgesic in term and near term neonates, its effectiveness and safety for PDA closure are uncertain because the drug is administered in high doses and there remain a limited number of observations in this specific subpopulation so far. Prospective comparative trials are reasonable and are urgently needed to establish both the effectiveness and safety data of paracetamol when used for this indication.