Treatment of persistent patent ductus arteriosus in preterm infants: time to accept the null hypothesis?

At a crossroads for early medical treatment of persistent patent ductus arteriosus in preterm infants

Administration of early medical therapy for the patent ductus arteriosus has ebbed and flowed through the years, with a multitude of studies failing to demonstrate a reduction in morbidity or mortality from ductal closure in the preterm population. Concerningly, an increasing number of studies have demonstrated an increase in morbidity, such as bronchopulmonary dysplasia and mortality with the use of early medical therapy to close the ductus. Considering information regarding potential risk without clear benefit in an overall cohort of preterm patients with a patent ductus, use of early medical therapy is increasingly challenging to justify and necessitates studies that will aid in identifying a patient population that would benefit from ductal closure and timing of therapy.

Patent Ductus Arteriosus Response to Treatment by Course and Associations with Perinatal and Clinical Factors

OBJECTIVE

 The objective of this study is to examine patent ductus arteriosus (PDA) response by treatment course and investigate associations with postmenstrual age (PMA), chronological age (CA), gestational age (GA), antenatal steroid exposure (ANS), birthweight (BW), weight at treatment initiation (WT), and PDA/left pulmonary artery (LPA) ratio.

STUDY DESIGN

 This is a single-center retrospective cohort study of preterm infants less than 37 weeks' GA born January 1, 2016 to December 31, 2018 who received acetaminophen and/or indomethacin for PDA treatment. Cox proportional hazards regression models were used to determine whether factors of interest were associated with PDA response to medical treatment.

RESULTS

 In total, 289 treatment courses were administered to 132 infants. Thirty-one (23%) infants experienced treatment-associated PDA closure. Ninety-four (71%) infants had evidence of PDA constriction following any treatment course. Ultimately, 84 (64%) infants experienced definitive PDA closure. For each 7-day increase in CA at the time of treatment initiation, the PDA was 59% less likely to close (p = 0.04) and 42% less likely to respond (i.e., constrict or close) to treatment (p < 0.01). PDA/LPA ratio was associated with treatment-associated PDA closure (p = 0.01). For every 0.1 increase in the PDA/LPA ratio, the PDA was 19% less likely to close in response to treatment.

CONCLUSION

 In this cohort, PDA closure is independent of PMA, GA, ANS, BW, and WT; however, CA at treatment initiation predicted both treatment-associated PDA closure and PDA response (i.e., constriction or closure), and PDA/LPA ratio was associated with treatment-associated closure. Most infants experienced PDA constriction rather than closure, despite receiving up to four treatment courses.

KEY POINTS

· Detailed PDA responses for up to four treatment courses provide a novel perspective.. · Chronological age at the start of treatment predicted treatment-associated PDA closure and response.. · For each 7-day increase in chronological age, the PDA was 59% less likely to close..

Association between patent ductus arteriosus flow and home oxygen therapy in extremely preterm infants

BACKGROUND

Central blood flow measurements include the estimation of right and left ventricular output (RVO, LVO), superior vena cava (SVC) flow, and calculated patent ductus arteriosus (PDA) flow. We aimed to provide an overview of the maturation patterns of these values and the relationship between PDA flow and the need for home oxygen therapy.

METHODS

This prospective single-center study was conducted in infants born at <26 weeks of gestation. We performed echocardiographic measurements five times during their life (from the 4th post-natal day to the 36th postmenstrual week).

RESULTS

Sixty patients with a mean birth weight of 680 (590, 760) g were included. Postnatal development of LVO and PDA flow peaked at the end of the second postnatal week (427 and 66 mL/kg/min, respectively). The RVO increased between days 4 and 7-8. The SVCF was most stable. The development curves of PDA flow differed between the groups with (n = 28; 47%) and without home oxygen therapy.

CONCLUSION

We present the central blood flow values and their postnatal development in infants <26 weeks of gestation. This study demonstrates the association between PDA flow and the future need for home oxygen therapy.

IMPACT

This study enriches our knowledge of the long-term development of central blood flow parameters and derived patent ductus arteriosus (PDA) flow in extremely preterm infants (<26 weeks). While pulmonary resistance decreased, PDA flow continued to increase from day 4 to the end of the second week of life. Similarly, left ventricular output increased as a marker of preload. The superior vena cava flow remained stable. The observed association between PDA flow and an unfavorable respiratory outcome is important for future studies focusing on the prevention of chronic lung disease.

Pharmacokinetic and Pharmacodynamic Analysis of Acetaminophen and Ibuprofen Dual Therapy for Patent Ductus Arteriosus Closure in Preterm Neonates at Less Than 29 Weeks of Gestation

Patent ductus arteriosus (PDA) is a blood vessel that critically supports fetal circulation. The ductus naturally closes within a few days after birth. However, it can stay open in premature neonates for an extended period of time, which is associated with increased mortality and various co-morbidities. Ibuprofen and indomethacin are currently the only 2 drugs approved for inducing PDA closure, but both have been associated with adverse renal and bleeding events. Clinical evidence suggests that combining acetaminophen (APAP) and ibuprofen treatments can decrease the need for surgical ligation. The objective of this study was to establish a disease-drug-trial model to characterize and predict PDA closure following single and combination drug therapy with ibuprofen and/or APAP in children at less than 29 weeks of gestation. The model was informed by a comprehensive literature review. The results of our analysis suggest that ibuprofen and APAP achieve therapeutic synergy. They further suggest that the younger the preterm neonates, the higher the treatment benefit. A 5-day oral dosing regimen consisting of ibuprofen (20 mg/kg Q24h on day 1, followed by 10 mg/kg Q24h on days 2-5) plus APAP (15 mg/kg Q6h) was deemed appropriate to achieve at least 90% PDA in all preterm neonates evaluated within 1 month of life. The model can now be used to design prospective pediatric trials to evaluate optimal drug combinations for PDA closure in preterm neonates and to refine optimal dosing regimens in cohorts of differing gestational age.

Secular Trends in Patent Ductus Arteriosus Management in Infants Born Preterm in the National Institute of Child Health and Human Development Neonatal Research Network

We evaluated changes in patent ductus arteriosus (PDA) diagnosis and treatment from 2012 through 2021 in a network of US academic hospitals. PDA treatment decreased among infants born at 26-28 weeks but not among infants born at 22-25 weeks. Rates of indomethacin use and PDA ligation decreased while acetaminophen use and transcatheter PDA closure increased.

Contemporary fluid management, humidity, and patent ductus arteriosus management strategy for premature infants among 336 hospitals in Asia

Objectives

The management of patent ductus arteriosus (PDA) is a critical concern in premature infants, and different hospitals may have varying treatment policies, fluid management strategies, and incubator humidity. The Asian Neonatal Network Collaboration (AsianNeo) collected data on prematurity care details from hospitals across Asian countries. The aim of this study was to provide a survey of the current practices in the management of PDA in premature infants in Asian countries.

Methods

AsianNeo performed a cross-sectional international questionnaire survey in 2022 to assess the human and physical resources of hospitals and clinical management of very preterm infants. The survey covered various aspects of hospitals resources and clinical management, and data were collected from 337 hospitals across Asia. The data collected were used to compare hospitals resources and clinical management of preterm infants between areas and economic status.

Results

The policy of PDA management for preterm infants varied across Asian countries in AsianNeo. Hospitals in Northeast Asia were more likely to perform PDA ligation (p < 0.001) than hospitals in Southeast Asia. Hospitals in Northeast Asia had stricter fluid restrictions in the first 24 h after birth for infants born at <29 weeks gestation (p < 0.001) and on day 14 after birth for infants born at <29 weeks gestation (p < 0.001) compared to hospitals in Southeast Asia. Hospitals in Northeast Asia also had a more humidified environment for infants born between 24 weeks gestation and 25 weeks gestation in the first 72 h after birth (p < 0.001). A logistic regression model predicted that hospitals were more likely to perform PDA ligation for PDA when the hospitals had a stricter fluid planning on day 14 after birth [Odds ratio (OR) of 1.70, p = 0.048], more incubator humidity settings (<80% vs. 80%-89%, OR of 3.35, p = 0.012 and <80% vs. 90%-100%, OR of 5.31, p < 0.001).

Conclusions

In advanced economies and Northeast Asia, neonatologists tend to adopt a more conservative approach towards fluid management, maintain higher incubator humidity settings and inclined to perform surgical ligation for PDA.

Trial of Selective Early Treatment of Patent Ductus Arteriosus with Ibuprofen

BACKGROUND

The cyclooxygenase inhibitor ibuprofen may be used to treat patent ductus arteriosus (PDA) in preterm infants. Whether selective early treatment of large PDAs with ibuprofen would improve short-term outcomes is not known.

METHODS

We conducted a multicenter, randomized, double-blind, placebo-controlled trial evaluating early treatment (≤72 hours after birth) with ibuprofen for a large PDA (diameter of ≥1.5 mm with pulsatile flow) in extremely preterm infants (born between 23 weeks 0 days' and 28 weeks 6 days' gestation). The primary outcome was a composite of death or moderate or severe bronchopulmonary dysplasia evaluated at 36 weeks of postmenstrual age.

RESULTS

A total of 326 infants were assigned to receive ibuprofen and 327 to receive placebo; 324 and 322, respectively, had data available for outcome analyses. A primary-outcome event occurred in 220 of 318 infants (69.2%) in the ibuprofen group and 202 of 318 infants (63.5%) in the placebo group (adjusted risk ratio, 1.09; 95% confidence interval [CI], 0.98 to 1.20; P = 0.10). A total of 44 of 323 infants (13.6%) in the ibuprofen group and 33 of 321 infants (10.3%) in the placebo group died (adjusted risk ratio, 1.32; 95% CI, 0.92 to 1.90). Among the infants who survived to 36 weeks of postmenstrual age, moderate or severe bronchopulmonary dysplasia occurred in 176 of 274 (64.2%) in the ibuprofen group and 169 of 285 (59.3%) in the placebo group (adjusted risk ratio, 1.09; 95% CI, 0.96 to 1.23). Two unforeseeable serious adverse events occurred that were possibly related to ibuprofen.

CONCLUSIONS

The risk of death or moderate or severe bronchopulmonary dysplasia at 36 weeks of postmenstrual age was not significantly lower among infants who received early treatment with ibuprofen than among those who received placebo. (Funded by the National Institute for Health Research Health Technology Assessment Programme; Baby-OSCAR ISRCTN Registry number, ISRCTN84264977.).

Early cardiac function and death, severe bronchopulmonary dysplasia and pulmonary hypertension in extremely preterm infants

BACKGROUND

Association between early cardiac function and neonatal outcomes are scarcely reported. The aim of the current study was to describe this association with death, severe bronchopulmonary dysplasia (BPD) and BPD-related pulmonary hypertension (PH).

METHODS

Retrospective cohort study of infants <29 weeks born between 2015 and 2019. Infants with clinically acquired echocardiography at ≤21 days after birth were included and data were extracted by an expert masked to outcomes.

RESULTS

A total of 176 infants were included. Echocardiogram was performed at a median of 9 days (IQR 5-13.5). Of these, 31 (18%) had death/severe BPD and 59 (33.5%) had death/BPD-related PH. Infants with death/severe BPD were of lower birth weight (745 [227] vs 852 [211] grams, p = 0.01) and more exposed to invasive ventilation, late-onset sepsis, inotropes and/or postnatal steroids. Early echocardiograms demonstrated decreased right ventricular [Tricuspid Annular Plane Systolic Excursion: 5.2 (1.4) vs 6.2 (1.5) cm, p = 0.03] and left ventricular function [Ejection fraction 53 (14) vs 58 (10) %, p = 0.03]. Infants with death/BPD-related PH had an increased Eccentricity index (1.35 [0.20] vs 1.26 [0.19], p = 0.02), and flat/bowing septum (19/54 [35%] vs 20/109 [18%], p = 0.021).

CONCLUSIONS

In extremely premature infants, altered ventricular function and increased pulmonary pressure indices within the first 21 days after birth, were associated with the combined outcome of death/severe BPD and death/BPD-related PH.

IMPACT

Decreased cardiac function on echocardiography performed during first three weeks of life is associated with severe bronchopulmonary dysplasia in extremely premature infants. In extreme preterm infants, echocardiographic signs of pulmonary hypertension in early life are associated with later BPD-related pulmonary hypertension close to 36 weeks post-menstrual age. Early cardiac markers should be further studied as potential intervention targets in this population. Our study is adding comprehensive analysis of echocardiographic data in infants born below 29 weeks gestational age.

Expectant management of patent ductus arteriosus for preterm infants: A meta-analysis of randomized controlled trials

We conducted this meta-analysis to compare expectant management of patent ductus arteriosus (PDA) with active treatment for PDA closure in preterm infants. Data from 7 randomized controlled trials (RCTs) showed that all-cause mortality and other clinical adverse outcomes did not differ between expectant management of PDA and active treatment. Future large-scale and double-blinded RCTs with a consistent definition for hemodynamically significant PDA, and focusing on clearly delineated high-risk subgroups or later selective treatment are needed to further evaluate the role of expectant management.

Transcatheter closure in preterm infants with patent ductus arteriosus: feasibility, results, hemodynamic monitoring and future prospectives

Ductal patency of preterm infants is potentially associated with long term morbidities related to either pulmonary overflow or systemic steal. When an interventional closure is needed, it can be achieved with either surgical ligation or a catheter-based approach.Transcatheter PDA closure is among the safest of interventional cardiac procedures and it is the first choice for ductal closure in adults, children, and infants weighing more than 6 kg. In preterm and very low birth weight infants, it is increasingly becoming a valid and safe alternative to ligation, especially for the high success rate and the minor invasiveness and side effects. Nevertheless, being it performed at increasingly lower weights and gestational ages, hemodynamic complications are possible events to be foreseen.Procedural steps, timing, results, possible complications and available monitoring systems, as well as future outlooks are here discussed.

New frontiers in neonatal red blood cell transfusion research

Red blood cell (RBC) transfusions are common in neonates requiring intensive care. Recent studies have compared restricted versus liberal transfusion guidelines, but limitations exist on evaluations of outcomes in populations that never required a transfusion compared to those receiving any transfusion. Although there are well-established risks associated with RBC transfusions, new data has emerged that suggests additional clinically relevant associations, including adverse neurodevelopmental outcomes, donor sex differences, and inflammation or immunosuppression. Further research is needed to delineate the magnitude of these risks and to further improve the safety of transfusions. The goal of this review is to highlight underappreciated, yet clinically important risks associated with neonatal RBC transfusions and to introduce several areas in which neonates may uniquely benefit from alterations in practice.

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.

Comparative Effectiveness of Surgical Ligation and Catheter Closure of Patent Ductus Arteriosus in Preterm Infants

To evaluate the association, if any, between closure modality (surgical ligation SL vs. catheter CC) of a hemodynamically significant patent ductus arteriosus (PDA), after failure of or contraindication to medical therapy, and immediate procedural complications, and post-procedure physiologic status in preterm (gestational age < 32 weeks) infants. In this single-center retrospective cohort study, data were accessed on infants < 32 weeks gestation, who underwent SL or CC of PDA, born from 2019-2021. The choice of modality was determined by parents, after they were provided information on both procedures. Our cohort (n = 112) included 36 (32.1%) infants who underwent SL while 76 (67.9%) underwent CC. The SL group of infants were significantly more immature at birth, younger on admission to the level IV NICU and received more mean (SD) surfactant doses than the CC group. Higher proportions of infants in the SL group had 5-min Apgar scores ≤ 5, seizures, severe intracranial hemorrhage and had received medical therapy for PDA. Both procedures were highly efficacious, with 1 unsuccessful device placement attempt and had low associated adverse events. Two (2.6%) infants had device migration 24 h after CC. SL was associated with a higher rate of immediate postoperative hypothermia whereas, in the CC group, mean airway pressure was significantly lower 48 h after, compared to before the procedure. SL and CC are comparable in short-term efficacy and safety for PDA closure. Long-term outcomes data are needed following both procedures.

Association of patent ductus arteriosus with extubation failure among preterm infants

BACKGROUND

Mechanical ventilation is associated with mortality/morbidities in preterm infants. Nearly a third of these infants fail extubation, and this may increase morbidities.

OBJECTIVE

To evaluate the association of moderate to large symptomatic patent ductus arteriosus (PDA) with failure of extubation among preterm infants.

METHODS

This was a retrospective study on preterm infants (birth weight <1250 g and gestational age ≥23 weeks) born between January 2009 and December 2016, who were mechanically ventilated and extubated within the first 60 days of age.

RESULTS

Three hundred and sixty infants were evaluated, of these, 26% failed, and 74% succeeded in the initial extubation attempt. On adjusted analysis, symptomatic PDA was associated with an increased risk of extubation failure.

CONCLUSION

The presence of symptomatic patent ductus arteriosus was associated with extubation failure. Further investigations are needed to establish whether there is a causal relationship between PDA and extubation failure and whether proactive screening for presence of PDA and treatment of the same, before extubation among these infants, improves chances of successful extubation and cardiorespiratory outcomes.

Interventions for patent ductus arteriosus (PDA) in preterm infants: an overview of Cochrane Systematic Reviews

BACKGROUND

Patent ductus arteriosus (PDA) is associated with significant morbidity and mortality in preterm infants. Several non-pharmacological, pharmacological, and surgical approaches have been explored to prevent or treat a PDA.

OBJECTIVES

To summarise Cochrane Neonatal evidence on interventions (pharmacological or surgical) for the prevention of PDA and related complications, and interventions for the management of asymptomatic and symptomatic PDA in preterm infants.

METHODS

We searched the Cochrane Database of Systematic Reviews on 20 October 2022 for ongoing and published Cochrane Reviews on the prevention and treatment of PDA in preterm (< 37 weeks' gestation) or low birthweight (< 2500 g) infants. We included all published Cochrane Reviews assessing the following categories of interventions: pharmacological therapy using prostaglandin inhibitor drugs (indomethacin, ibuprofen, and acetaminophen), adjunctive pharmacological interventions, invasive PDA closure procedures, and non-pharmacological interventions. Two overview authors independently checked the eligibility of the reviews retrieved by the search, and extracted data from the included reviews using a predefined data extraction form. Any disagreements were resolved by discussion with a third overview author. Two overview authors independently assessed the methodological quality of the included reviews using the AMSTAR 2 (A MeaSurement Tool to Assess systematic Reviews) tool. We reported the GRADE certainty of evidence as assessed by the respective review authors using summary of findings tables.

MAIN RESULTS

We included 16 Cochrane Reviews, corresponding to 138 randomised clinical trials (RCT) and 11,856 preterm infants, on the prevention and treatment of PDA in preterm infants. One of the 16 reviews had no included studies, and therefore, did not contribute to the results. Six reviews reported on prophylactic interventions for the prevention of PDA and included pharmacological prophylaxis with prostaglandin inhibitor drugs, prophylactic surgical PDA ligation, and non-pharmacologic interventions (chest shielding during phototherapy and restriction of fluid intake); one review reported on the use of indomethacin for the management of asymptomatic PDA; nine reviews reported on interventions for the management of symptomatic PDA, and included pharmacotherapy with prostaglandin inhibitor drugs in various routes and dosages, surgical PDA ligation, and adjunct therapies (use of furosemide and dopamine in conjunction with indomethacin). The quality of reviews varied. Two reviews were assessed to be high quality, seven reviews were of moderate quality, five of low quality, while two reviews were deemed to be of critically low quality. For prevention of PDA, prophylactic indomethacin reduces severe intraventricular haemorrhage (IVH; relative risk (RR) 0.66, 95% confidence interval (CI) 0.53 to 0.82; 14 RCTs, 2588 infants), and the need for invasive PDA closure (RR 0.51, 95% CI 0.37 to 0.71; 8 RCTs, 1791 infants), but it does not appear to affect the composite outcome of death or moderate/severe neurodevelopmental disability (RR 1.02, 95% CI 0.90 to 1.15; 3 RCTs, 1491 infants). Prophylactic ibuprofen probably marginally reduces severe IVH (RR 0.67, 95% CI 0.45 to 1.00; 7 RCTs, 925 infants; moderate-certainty evidence), and the need for invasive PDA closure (RR 0.46, 95% CI 0.22 to 0.96; 7 RCTs, 925 infants; moderate-certainty evidence). The evidence is very uncertain on the effect of prophylactic acetaminophen on severe IVH (RR 1.09, 95% CI 0.07 to 16.39; 1 RCT, 48 infants). Necrotising enterocolitis (NEC) was lower with both prophylactic surgical ligation (RR 0.25, 95% CI 0.08 to 0.83; 1 RCT, 84 infants), and fluid restriction (RR 0.43, 95% CI 0.21 to 0.87; 4 RCTs, 526 infants). For treatment of asymptomatic PDA, indomethacin appears to reduce the development of symptomatic PDA post-treatment (RR 0.36, 95% CI 0.19 to 0.68; 3 RCTs, 97 infants; quality of source review: critically low). For treatment of symptomatic PDA, all available prostaglandin inhibitor drugs appear to be more effective in closing a PDA than placebo or no treatment (indomethacin: RR 0.30, 95% CI 0.23 to 0.38; 10 RCTs, 654 infants; high-certainty evidence; ibuprofen: RR 0.62, 95% CI 0.44 to 0.86; 2 RCTs, 206 infants; moderate-certainty evidence; early administration of acetaminophen: RR 0.35, 95% CI 0.23 to 0.53; 2 RCTs, 127 infants; low-certainty evidence). Oral ibuprofen appears to be more effective in PDA closure than intravenous (IV) ibuprofen (RR 0.38, 95% CI 0.26 to 0.56; 5 RCTs, 406 infants; moderate-certainty evidence). High-dose ibuprofen appears to be more effective in PDA closure than standard-dose ibuprofen (RR 0.37, 95% CI 0.22 to 0.61; 3 RCTs, 190 infants; moderate-certainty evidence). With respect to adverse outcomes, compared to indomethacin administration, NEC appears to be lower with ibuprofen (any route; RR 0.68, 95% CI 0.49 to 0.94; 18 RCTs, 1292 infants; moderate-certainty evidence), oral ibuprofen (RR 0.41, 95% CI 0.23 to 0.73; 7 RCTs, 249 infants; low-certainty evidence), and with acetaminophen (RR 0.42, 95% CI 0.19 to 0.96; 4 RCTs, 384 infants; low-certainty evidence). However, NEC appears to be increased with a prolonged course of indomethacin versus a shorter course (RR 1.87, 95% CI 1.07 to 3.27; 4 RCTs, 310 infants).

AUTHORS' CONCLUSIONS

This overview summarised the evidence from 16 Cochrane Reviews of RCTs regarding the effects of interventions for the prevention and treatment of PDA in preterm infants. Prophylactic indomethacin reduces severe IVH, but does not appear to affect the composite outcome of death or moderate/severe neurodevelopmental disability. Prophylactic ibuprofen probably marginally reduces severe IVH (moderate-certainty evidence), while the evidence is very uncertain on the effect of prophylactic acetaminophen on severe IVH. All available prostaglandin inhibitor drugs appear to be effective in symptomatic PDA closure compared to no treatment (high-certainty evidence for indomethacin; moderate-certainty evidence for ibuprofen; low-certainty evidence for early administration of acetaminophen). Oral ibuprofen appears to be more effective in PDA closure than IV ibuprofen (moderate-certainty evidence). High dose ibuprofen appears to be more effective in PDA closure than standard-dose ibuprofen (moderate-certainty evidence). There are currently two ongoing reviews, one on fluid restriction for symptomatic PDA, and the other on invasive management of PDA in preterm infants.

Expectant Management or Early Ibuprofen for Patent Ductus Arteriosus

BACKGROUND

Cyclooxygenase inhibitors are commonly used in infants with patent ductus arteriosus (PDA), but the benefit of these drugs is uncertain.

METHODS

In this multicenter, noninferiority trial, we randomly assigned infants with echocardiographically confirmed PDA (diameter, >1.5 mm, with left-to-right shunting) who were extremely preterm (<28 weeks' gestational age) to receive either expectant management or early ibuprofen treatment. The composite primary outcome included necrotizing enterocolitis (Bell's stage IIa or higher), moderate to severe bronchopulmonary dysplasia, or death at 36 weeks' postmenstrual age. The noninferiority of expectant management as compared with early ibuprofen treatment was defined as an absolute risk difference with an upper boundary of the one-sided 95% confidence interval of less than 10 percentage points.

RESULTS

A total of 273 infants underwent randomization. The median gestational age was 26 weeks, and the median birth weight was 845 g. A primary-outcome event occurred in 63 of 136 infants (46.3%) in the expectant-management group and in 87 of 137 (63.5%) in the early-ibuprofen group (absolute risk difference, -17.2 percentage points; upper boundary of the one-sided 95% confidence interval [CI], -7.4; P<0.001 for noninferiority). Necrotizing enterocolitis occurred in 24 of 136 infants (17.6%) in the expectant-management group and in 21 of 137 (15.3%) in the early-ibuprofen group (absolute risk difference, 2.3 percentage points; two-sided 95% CI, -6.5 to 11.1); bronchopulmonary dysplasia occurred in 39 of 117 infants (33.3%) and in 57 of 112 (50.9%), respectively (absolute risk difference, -17.6 percentage points; two-sided 95% CI, -30.2 to -5.0). Death occurred in 19 of 136 infants (14.0%) and in 25 of 137 (18.2%), respectively (absolute risk difference, -4.3 percentage points; two-sided 95% CI, -13.0 to 4.4). Rates of other adverse outcomes were similar in the two groups.

CONCLUSIONS

Expectant management for PDA in extremely premature infants was noninferior to early ibuprofen treatment with respect to necrotizing enterocolitis, bronchopulmonary dysplasia, or death at 36 weeks' postmenstrual age. (Funded by the Netherlands Organization for Health Research and Development and the Belgian Health Care Knowledge Center; BeNeDuctus ClinicalTrials.gov number, NCT02884219; EudraCT number, 2017-001376-28.).

Impact of early screening echocardiography and targeted PDA treatment on neonatal outcomes in "22-23" week and "24-26" infants

The hemodynamically significant patent ductus arteriosus (hsPDA) is a controversial topic in neonatology, particularly among neonates at the earliest gestational ages of 22+0-23+6 weeks. There is little, to no data on the natural history or impact of the PDA in extremely preterm babies. In addition, these high-risk patients have typically been excluded from randomized clinical trials of PDA treatment. In this work, we present the impact of early hemodynamic screening (HS) of a cohort of patients born 22+0-23+6 weeks gestation who either were diagnosed with hsPDA or died in the first postnatal week as compared to a historical control (HC) cohort. We also report a comparator population of 24+0-26+6 weeks gestation. All patients in the HS epoch were evaluated between 12-18h postnatal age and treated based on disease physiology whereas the HC patients underwent echocardiography at the discretion of the clinical team. We demonstrate a two-fold reduction in the composite primary outcome of death prior to 36 weeks or severe BPD and report a lower incidence of severe intraventricular hemorrhage (n=5, 7% vs n=27, 27%), necrotizing enterocolitis (n=1, 1% vs n=11, 11%) and first-week vasopressor use (n=7, 11% vs n=40, 39%) in the HS cohort. HS was also associated with an increase in survival free of severe morbidity from the already high rate of 50% to 73% among neonates <24 weeks gestation. We present a biophysiological rationale behind the potential modulator role of hsPDA on these outcomes and review the physiology relevant to neonates born at these extremely preterm gestations. These data highlight the need for further interrogation of the biological impact of hsPDA and impact of early echocardiography directed therapy in infants born less than 24 weeks gestation.

Clinical outcomes of different patent ductus arteriosus treatment in preterm infants born between 28 and 32 weeks in Taiwan

BACKGROUND

The patent ductus arteriosus (PDA) treatment in very preterm infants is controversial. This study focused on preterm infants born at 28-32 weeks of gestation and analyzed the association between various PDA treatments and clinical outcomes.

METHODS

We conducted a retrospective cohort study of infants born at 28-32 weeks of gestation between 2016 and 2019 at 22 hospitals in the Taiwan Premature Infant Follow-up Network. We categorized the infants into four groups according to treatment strategies: medication, primary surgery, medication plus surgery, or conservative treatment.

RESULTS

A total of 1244 infants presented with PDA, and 761 (61.1%) were treated. Medication was the predominant treatment (50.0%), followed by conservative treatment (38.9%), medication plus surgery (7.6%), and primary surgery (3.5%). The risk of mortality was not reduced in the active treatment group compared to the conservative treatment group. There was a higher prevalence of severe intraventricular hemorrhage, necrotizing enterocolitis (NEC), and any degree of bronchopulmonary dysplasia (BPD) in both the primary surgery and medication plus surgery groups than in the conservative treatment group. After adjustment, both the primary surgery and medication plus surgery groups still had higher odds ratios for the occurrence of NEC and any degree of BPD.

CONCLUSIONS

Compared with active PDA treatment, conservative treatment for PDA did not increase the risk of mortality and morbidity in very preterm infants born at 28-32 weeks of gestation. The risks and benefits of surgery (PDA ligation) in these infants must be considered cautiously.

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.

Patent ductus arteriosus and spontaneous intestinal perforation in a cohort of preterm infants

OBJECTIVE

To assess whether either duration and magnitude of ductal shunt or medical treatment for patent ductus arteriosus (PDA) are related to spontaneous intestinal perforation (SIP).

STUDY DESIGN

Clinical charts of infants <29 weeks' gestation born from 2006 to 2018 were reviewed. Echocardiographic examinations were evaluated according to McNamara and Sehgal's staging system.

RESULTS

A higher percentage of patients with SIP had a hemodynamically significant PDA (HSPDA) and was treated with either NSAIDs or paracetamol (79% vs 53% and 81% vs 54%, respectively). Among non-treated patients, we found a 1.32 increase in the odds of SIP per day of persistence of HSPDA. In the cohort of patients treated despite the absence of HSPDA, we found a 2.35 increase in the odds of SIP per dose of drug administered.

CONCLUSION

Both treating a non-HSPDA and leaving a HSPDA to its natural history seem to be associated with SIP.

Dual medication therapy (acetaminophen and ibuprofen) for the management of patent ductus arteriosus in preterm infants: a systematic review and meta-analysis

OBJECTIVE

To examine the efficacy of dual medication therapy (intervention) (DMT: acetaminophen and ibuprofen) vs. single medication therapy (control) (SMT: ibuprofen) for medical management of PDA (outcomes) in preterm infants (population).

STUDY DESIGN

We systematically searched multiple sources to identify randomized controlled trials (RCT) and non-randomized studies (NRS) that compared DMT to SMT for management of hemodynamically significant PDA.

RESULTS

We identified two RCTs and four NRS. There were no differences in the rates of successful PDA closure following the first treatment course between DMT and SMT (RR = 1.23 [95% CI 0.89-1.70] for NRS and RR = 1.18 [95% CI 0.66-2.10] for RCTs), nor were there significant differences in secondary outcomes and adverse events including PDA ligation, bronchopulmonary dysplasia, and necrotizing enterocolitis etc. Markers of hepatic/renal function did not change significantly during treatment.

CONCLUSION

We found no evidence for superiority of DMT over SMT in PDA management.

Mortality and Morbidity in Premature Infants: An East and West Comparative Study

OBJECTIVE

Survival of preterm infants differs dramatically depending on birthplace. No previous studies have compared outcomes of preterm infants between low middle-income and high-income countries such as India and the United States. The purpose of this study is to evaluate differences in care practices, resources, mortality, and morbidities in preterm infants with birth weight 700 to 1,500 g between two major neonatal centers in these countries.

STUDY DESIGN

This is a retrospective cohort study with de-identified data from Fernandez Hospital (FH) in Hyderabad, India, and Texas Children's Hospital (TCH) in Houston, TX, for infants born January 2016 to December 2018, and weighing 700 to 1,500 g at birth. The primary outcome was death before hospital discharge.

RESULTS

Of 1,195 infants, 736 were admitted to FH and 459 were admitted to TCH. After controlling for differences in gestational age, small for gestational age, and antenatal corticosteroid use, TCH patients had lower mortality before hospital discharge (adjusted odds ratio [aOR] = 0.28, 95% confidence interval [CI]: 0.16-0.48, p < 0.001) and more bronchopulmonary dysplasia (BPD; aOR = 2.2, 95% CI: 1.51-3.21, p < 0.001). The composite outcome of death or BPD and death or any major morbidity (BPD or intraventricular hemorrhage grade II or more or periventricular leukomalacia grade II or more or retinopathy of prematurity requiring treatment) were not different.

CONCLUSION

In this study, TCH infants had decreased odds of death before hospital discharge compared with FH but higher odds of BPD, which may be related to increased survival and differences in care practices.

KEY POINTS

· Few studies compared outcomes of premature infants between different high-income countries.. · There are no studies comparing preterm infants between low middle-income and high-income countries such as India and the United States.. · This study evaluated detailed comparison of care practices and infrastructure of NICUs in India and United states..

Patent Ductus Arteriosus: A Contemporary Perspective for the Pediatric and Adult Cardiac Care Provider

The burden of patent ductus arteriosus (PDA) continues to be significant. In view of marked differences in preterm infants versus more mature, term counterparts (viewed on a continuum with adolescent and adult patients), mechanisms regulating ductal patency, genetic contributions, clinical consequences, and diagnostic and treatment thresholds are discussed separately, when appropriate. Among both preterm infants and older children and adults, a range of hemodynamic profiles highlighting the markedly variable consequences of the PDA are provided. In most contemporary settings, transcatheter closure is preferable over surgical ligation, but data on longer-term outcomes, particularly among preterm infants, are lacking. The present review provides recommendations to identify gaps in PDA diagnosis, management, and treatment on which subsequent research can be developed. Ultimately, the combination of refined diagnostic thresholds and expanded treatment options provides the best opportunities to address the burden of PDA. Although fundamental gaps remain unanswered, the present review provides pediatric and adult cardiac care providers with a contemporary framework in PDA care to support the practice of evidence-based medicine.

Effectiveness of Dual Medication Therapy (Oral Acetaminophen and Oral Ibuprofen) for the Management of Patent Ductus Arteriosus in Extremely Premature Infants: A Feasibility Trial

OBJECTIVE

The study aimed to evaluate the efficacy of dual medication therapy (DMT) with oral acetaminophen and oral ibuprofen for the closure of a hemodynamically significant patent ductus arteriosus (hsPDA).

STUDY DESIGN

In a prospective case-control cohort study (July 2017-May 2019), infants <29 weeks' gestational age and birth weight <1,000 g at ≤14 postnatal days with hsPDA and ratio of the smallest ductal diameter to the ostium of the left pulmonary artery diameter >0.5 were eligible. Infants received 10 mg/kg oral ibuprofen followed by two additional doses of 5 mg/kg at 24 and 48 hours after the initial ibuprofen dose and concomitant treatment with 15 mg/kg oral acetaminophen every 6 hours for 3 days (12 doses). Success of PDA treatment was defined as a small or absent PDA as ascertained by echocardiographic measurements. The p-values of comparisons were adjusted for multiple comparisons to preserve an error rate of 5%.

RESULTS

Overall, 20 infants received oral DMT and 11 infants received intravenous single medication therapy (SMT) with ibuprofen. The rates of successful PDA treatment following the first treatment in DMT and SMT groups were not statistically different (11/20 [55%] vs. 4/11 [36%], p = 0.46). However, DMT significantly decreased PDA size (mean difference = 0.54 mm, 95% confidence interval [CI]: 0.21-0.96, adjusted p-value = 0.0002) and PDA/LPA ratio (mean difference = 0.27, 95% CI: 0.10-0.47, adjusted p-value = 0.0004). We observed no evidence of hematologic, hepatic, or renal impairment.

CONCLUSION

DMT achieved a greater degree of PDA closure than SMT and did not result in abnormalities in hepatic and renal profile.

KEY POINTS

· No consensus on optimal medication for PDA treatment is available.. · Dual oral medication therapy (ibuprofen and acetaminophen) could be an effective alternative treatment for PDA.. · Dual oral medication therapy (ibuprofen and acetaminophen) may have a better safety profile than currently approved medications such as intravenous indomethacin and intravenous ibuprofen..

Ligation of patent ductus arteriosus through left anterior mini-thoracotomy in preterm infants

OBJECTIVE

Patent ductus arteriosus is an important cause of morbidity and mortality, especially in very low birth weight infants. The aim of the study is to report our single-centre short-term results of preterm patients who underwent ligation through left anterior mini-thoracotomy .

METHODS

Data of 27 preterm infants operated by the same surgeon who underwent Patent ductus arteriosus (PDA) closure with left anterior mini-thoracotomy technique between November 2020 and January 2022 at a single institution were reviewed. The patients were divided into two groups according to their weight at the time of surgery. Data on early postoperative outcomes and survival rates after discharge were collected.

RESULTS

Twenty-seven patients with a mean (±SD) gestational age of 25.8 (±2.0) weeks and a mean birth weight of 1027 (±423) g were operated using left anterior mini-thoracotomy technique. The lowest body weight was 480 g. Complications such as bleeding, abnormal healing of incision, or pneumothorax were not seen. There were 8 mortalities after the operation (29,6 %). The causes of the deaths were sepsis, necrotising enterocolitis, hydrops fetalis, hepatoblastoma, and intracranial bleeding. There was no statistically significant difference in the rates of complication between the groups.

CONCLUSIONS

Left anterior mini-thoracotomy technique can be performed as the first choice when transcatheter intervention cannot be applied in preterm infants. It provides easy access to the PDA, a good exposure, minimal contact with the lungs, good cosmetic results in early and mid-term and shortens the operation time, especially in very low birth weight preterm babies. However, early ligation may be helpful to minimise the complications related to PDA.

Natural evolution of the patent ductus arteriosus in the extremely premature newborn and respiratory outcomes

OBJECTIVE

Evaluate spontaneous closure of the patent ductus arteriosus (PDA) in extremely preterm infants and their respiratory outcomes, especially at <26 weeks gestational age (GA).

STUDY DESIGN

Retrospective study in <29 weeks, admitted within 24 h after birth (Feb 2015 and Dec 2019). Infants without any intervention to promote ductal closure, ≥1 echocardiography, and alive at discharge were included.

RESULTS

Two hundred and fourteen infants (average GA 26.3 ± 1.5 weeks) were included; 84 (39%) <26 weeks. PDA closed spontaneously in 194 (91%); 76/84 (90%) for infants <26 weeks. PDA closure was ascertained on an echocardiography performed at a median age of 36.4 [34.4-40.1] weeks. Rate of moderate-to-severe bronchopulmonary dysplasia decreased throughout the study period (OR for year of birth: 0.70 [95% CI: 0.57-0.87], p = 0.001).

CONCLUSION

Majority of extremely preterm infants, including <26 weeks, had spontaneous closure of the ductus before term corrected age. There was a concomitant improvement of respiratory outcomes.

Is early patent ductus arteriosus ligation helpful in premature neonates? A 10-year retrospective study

BACKGROUND

To compare short and long outcomes between early (≤ 28 days) (EL) and late ligation (LL) groups. To explore factors predicting early extubation (≤ 7 days) after patent ductus arteriosus (PDA) ligation.

METHODS

We conducted a single center, retrospective cohort study of preterm infants < 32 weeks who underwent surgical ligation over a 10-year period (2009-2019).

RESULTS

A total of 133 infants underwent PDA ligation, in the study period. Both groups had similar short-term outcome such as bronchopulmonary dysplasia (BPD) or death (96% vs. 98%, P = 0.64) and long-term clinical outcomes including Bayley's assessment at 2 years corrected age. Fewer infants in the EL group developed severe BPD (63% vs. 81%, P = 0.02). Age at ligation had adjusted odds ratio of 1.04 with over lapping confidence interval (95% CI 1.0-1.1, P = 0.02) for severe BPD/death. There was no difference in day of extubation between the EL and LL group (8 days vs. 7 days, P = 0.85). Left atrium/aortic root ratio of ≥ 1.75 would give sensitivity of 41% and 80% specificity for early extubation (area under the curve of 0.61). There was marginal reduction of hospital stay in the EL group [113 (105-121) days vs. 115 (107-123) days; log rank P = 0.026].

CONCLUSION

EL can be delivered safely with a clinically important lower incidence of severe BPD and shorter duration of hospital stay compared to LL.

A Novel Patent Ductus Arteriosus Severity Score to Predict Clinical Outcomes in Premature Neonates

Background: Patent Ductus Arteriosus (PDA) in premature neonates has been associated with comorbidities including chronic lung disease (CLD), and death. However, the treatment of PDA remains controversial. There have been several echocardiographic variables previously used to determine the hemodynamic significance of PDA but their utility in early prediction of clinical outcomes is not well studied. Objective: The objective of our study was to evaluate the use of a severity scoring system incorporating markers of systemic under perfusion, pulmonary over perfusion and left ventricular (LV) function in predicting clinical outcomes in premature neonates. Methods: It is a single center prospective observational study involving newborns < 32 weeks’ gestation. An echocardiogram was done within seven days of life to measure variables previously known to predict severity of shunting in PDA including pulmonary perfusion index (PPI). Predictors of CLD/death were identified using multivariate logistic regression. A severity score was derived and its ability to predict clinical outcomes was tested using a receiver operating characteristic curve. Results: We studied 98 infants with a mean (SD) gestation of 28.9 ± 1.91 weeks and birth weight of 1228.06 ± 318.94 g, respectively. We identified five echocardiographic variables along with gestational age that was independently associated with the outcome variable (PPI, LV output, Superior Mesenteric Artery [SMA] Velocity Time Integral [VTI], Peak diastolic flow velocity in Pulmonary Vein [PV Vd], and reversal of flow in diastole in descending aorta [DFR]). The range of severity score was 0 (low risk) to 12 (high risk). A higher score was associated with the primary outcome variable of CLD/death (7.5 [1.2] vs. 3.6 [1.5], p < 0.001). Our severity score had an area under the curve of 0.97 (95% CI 0.93−0.99, p < 0.001) for predicting CLD/death. Conclusion: Our new PDA severity score of 5.5 has a sensitivity and specificity of 94% and 93%, and positive and negative predictive values of 94% and 93%, respectively.

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

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.

Clinical and echocardiographic characteristics associated with evolution of patent ductus arteriosus in preterm neonates: A prospective cohort study

BACKGROUND

In preterm infants, persistence of ductus arteriosus is an important medical condition. Functional echocardiography for patent ductus arteriosus (PDA) may guide clinical decision-making regarding treatment requirement strategies. Objectives of the study were to assess the trends of clinical and functional echocardiographic parameters with evolution of ductus arteriosus in babies≤1250 gm of birth weight and to evaluate whether there is any association of these parameters with persistence of ductus.

METHODS

In this prospective observational study, recruited babies were assessed serially for clinical events and functional echocardiography. Babies were classified into three groups: without PDA, with PDA but PDA spontaneously closed (within 7 days) and persistent PDA.

RESULT

We included 143 infants (Birth weight 1017±179 g, gestational age 30.8±2.7 weeks). Out of 60 babies with PDA, PDA failed to close spontaneously in first week in 32 (53.4 %) infants. PDA Doppler flow pattern on day 3 was found to be one of the most significant markers for future ductus. The highest frequency of growing pattern (37.5%) and pulsatile pattern (59.4%) was seen in persistence ductus group. PDA diameter and LA/Ao ratio were found strongly correlated with all other variables except E/A ratio.

CONCLUSION

We noticed persistence of ductus in preterm infants had significant clinical and echocardiographic association. PDA doppler flow pattern on day 3 was found to be a significant marker for future behaviour of ductus. Significant correlation was found among individual functional echocardiographic parameters in babies with PDA. This would guide judicious treatment of PDA in preterm neonates.

Patent ductus arteriosus, tracheal ventilation, and the risk of bronchopulmonary dysplasia

BACKGROUND

An increased risk for bronchopulmonary dysplasia (BPD) exists when moderate-to-large patent ductus arteriosus shunts (hsPDA) persist beyond 14 days.

GOAL

To examine the interaction between prolonged exposures to tracheal ventilation (≥10 days) and hsPDA on the incidence of BPD in infants <28 weeks gestation.

STUDY DESIGN

Predefined definitions of prolonged ventilation (≥10 days), hsPDA (≥14 days), and BPD (room air challenge test at 36 weeks) were used to analyze deidentified data from the multicenter TRIOCAPI RCT in a secondary analysis of the trial.

RESULTS

Among 307 infants who survived >14 days, 41 died before 36 weeks. Among survivors, 93/266 had BPD. The association between BPD and hsPDA depended on the length of intubation. In multivariable analyses, prolonged hsPDA shunts were associated with increased BPD (odds ratio (OR) (95% confidence interval (CI)) = 3.00 (1.58-5.71)) when infants required intubation for ≥10 days. In contrast, there was no significant association between hsPDA exposure and BPD when infants were intubated <10 days (OR (95% CI) = 1.49 (0.98-2.26)). A similar relationship between prolonged hsPDA and length of intubation was found for BPD/death (n = 307): infants intubated ≥10 days: OR (95% CI) = 2.41 (1.47-3.95)); infants intubated <10 days: OR (95% CI) = 1.37 (0.86-2.19)).

CONCLUSIONS

Moderate-to-large PDAs were associated with increased risks of BPD and BPD/death-but only when infants required intubation ≥10 days.

IMPACT

Infants with a moderate-to-large hsPDA that persist beyond 14 days are only at risk for developing BPD if they also receive prolonged tracheal ventilation for ≥10 days. Infants who receive less ventilatory support (intubation for <10 days) have the same incidence of BPD whether the ductus closes shortly after birth or whether it persists as a moderate-to-large shunt for several weeks. Early PDA closure may be unnecessary in infants who require short durations of intubation since the PDA does not seem to alter the incidence of BPD in infants who require intubation for <10 days.

Prophylactic Low-Dose Paracetamol Administration for Ductal Closure and Microstructural Brain Development in Preterm Infants

INTRODUCTION

Prophylactic low-dose paracetamol administration is used to induce closure of the ductus arteriosus. Effects on the neurological outcome in preterm infants remain unknown. We compared microstructural brain development in very preterm infants with and without exposure to prophylactic paracetamol by using MR-based diffusion tensor imaging.

MATERIALS AND METHODS

Infants aged <32 gestational weeks born between October 2014 and December 2018 received prophylactic paracetamol (10 mg/kg intravenously every 8 h until echocardiography after at least 72 h) and form the paracetamol group; infants born between February 2011 and September 2014 form the control group. Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) at term-equivalent age were measured in 14 defined cerebral regions and compared between the groups.

RESULTS

Included in the study were 340 infants, of whom 217 received prophylactic paracetamol, and 123 formed the control group. The paracetamol group showed significantly higher FA values and lower ADC values in the splenium of the corpus callosum, as well as higher FA values in the pons bilaterally, the left middle cerebellar peduncle, the right occipital white matter, and the right posterior limb of the internal capsule (p ≤ 0.02).

CONCLUSION

The perceived safety of prenatal paracetamol exposure has been questioned in recent years. We found no impairment on microstructural maturation processes in the brain of preterm infants at term-equivalent age following early paracetamol administration. The clinical relevance of these imaging findings has to be determined in long-term follow-up studies on neurodevelopmental outcome.

Low Rate of Spontaneous Closure in Premature Infants Discharged with a Patent Ductus Arteriosus: A Multicenter Prospective Study

OBJECTIVES

To assess the rate of spontaneous closure and the incidence of adverse events in infants discharged home with a patent ductus arteriosus.

STUDY DESIGN

In a prospective multicenter study, we enrolled 201 premature infants (gestational age of 23-32 weeks at birth) discharged home with a persistently patent ductus arteriosus (PDA) and followed their PDA status at 6-month intervals through 18 months of age. The primary study outcome was the rate and timing of spontaneous ductal closure. Secondary outcomes included rate of assisted closure and the incidence of serious adverse events.

RESULTS

Spontaneous ductal closure occurred in 95 infants (47%) at 12 months and 117 infants (58%) by 18 months. Seventeen infants (8.4%) received assisted closure with surgical ligation or device assisted occlusion. Three infants died (1.5%). Although infants with spontaneous closure had a higher mean birth weight and gestational age compared with infants with a persistent PDA or assisted closure, we did not identify other factors predictive of spontaneous closure.

CONCLUSIONS

Spontaneous closure of the PDA occurred in slightly less than one-half of premature infants discharged with a patent ductus by 1 year, lower than prior published reports. The high rate of assisted closure and/or adverse events in this population warrants close surveillance following discharge.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT02750228.

Impact of patent ductus arteriosus shunt size and duration on risk of death or severe respiratory morbidity in preterm infants born in China

The purpose of this study is to assess whether duration and size of the arterial duct were associated with severe respiratory morbidity and mortality in preterm infants. All echocardiography evaluations for patent ductus arteriosus (PDA) in a cohort of preterm infants, born at a gestational age less than 28 weeks, from birth up to 36 weeks of postconceptional age or final ductal closure were reviewed. Ductal size was measured at the pulmonary end. PDA was classified as small (E1: ductal diameter (DD) ≤ 1.5 mm), moderate (E2: 1.5 mm < DD ≤ 2.5 mm), or large (E3) (DD > 2.5 mm). The primary outcome was adverse outcome defined by the composite outcome of bronchopulmonary dysplasia (BPD) or death. Infants in whom the primary outcome occurred were classified as "high-risk" whereas patients who did not satisfy this outcome were classified as "low-risk". Intergroup comparison (high vs. low risk) was performed using univariate and multivariate analyses. A total of 135 infants, born between 2010 and 2020, were evaluated. The primary outcome was satisfied in 46 (34.1%) patients. The high-risk group was characterized by increased duration of exposure to PDA of any (E1/E2/E3) grade (44 vs. 25.5 days, p = .0004), moderate or large (E2/E3) PDA (30.5 vs. 11.5 days, p < .0001), moderate (E2) PDA (10.8 vs.6 days, p = 0.05), and large (E3) PDA (11.5 vs.0 days, p < .0001) compared with low-risk group. Lower gestational age, prolonged duration of mechanical ventilation, higher rate of inotrope use, pharmacological therapy, and PDA ligation were also associated with development of BPD or death (high-risk group). After adjusting for confounders, the rate of inotrope use [OR 2.688, 95% CI (1.011-7.142), p = 0.047], duration of large (E3) PDA [OR 1.060, 95% CI (1.005-1.118), p = 0.03], and mechanical ventilation [OR 1.130, 95% CI (1.064-1.200), p = 0.0001] were independently associated with the composite of BPD or death. Among infants who developed BPD, 27 were classified as grade I and 18 as grade II BPD, respectively. Infants with grade II BPD had prolonged MV (20.0 vs. 9.0 days, p = 0.024), prolonged exposure to PDA of any grade (55.8 vs. 36.0 days, p = 0.03), and prolonged exposure to large (E3) PDA compared with infants with grade I BPD.   Conclusion: Prolonged exposure to a large PDA was associated with severe respiratory morbidity and mortality in preterm infants. The modulator role of early intervention, in the most pathologic shunts, on severe respiratory morbidity in preterm infants should be tested in well-designed clinical trials. What is Known: • Current guidelines recommended against accelerating PDA closure of preterm infants within 2 weeks of life, with low certainty evidence indicating improved long-term outcomes. • Recent studies suggest that conservative approach regarding PDA management has detrimental effects on the respiratory outcomes in a subgroup population. What is New: • Persistent patency of significant PDA is associated with increased risk of BPD/death in extremely preterm infants. • Targeted intervention of PDA is beneficial for the at-risk preterm infants with increased PDA hemodynamic significance.

Patent ductus arteriosus: From pharmacology to surgery

Patent ductus arteriosus (PDA) may be found in 0.1-0.2% of term infants, but the average incidence is at least five-fold higher in premature infants, correlating inversely with birth weight and gestational age. While not all patients with a PDA require treatment, the deleterious effects of persistent left-to-right shunting across the ductus can have important short- and long-term consequences. Medical and interventional approaches to PDA closure have evolved greatly in the past decade and add to the decision-making pathways. This article summarizes the pathophysiology of PDA and characterizes the medical, surgical and endovascular treatment approaches.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Outcomes for Infants Born in Perinatal Centers Performing Fewer Surgical Ligations for Patent Ductus Arteriosus: A Swiss Population-Based Study

OBJECTIVE

To assess patent ductus arteriosus treatment variation between Swiss perinatal centers and to determine its effect on outcome in a population-based setting.

STUDY DESIGN

This was a retrospective cohort study of infants born less than 28 weeks of gestation between 2012 and 2017. Outcomes between surgically ligated and pharmacologically treated infants as well as infants born in centers performing ≤10% ligation ("low" group) and >10% ("high" group) were compared using logistic regression and 1:1 propensity score matching. Matching was based on case-mix and preligation confounders: intraventricular hemorrhages grades 3-4, necrotizing enterocolitis, sepsis, and ≥28 days' oxygen supply.

RESULTS

Of 1389 infants, 722 (52%) had pharmacologic treatment and 156 (11.2%) received surgical ligation. Compared with infants who received pharmacologic treatment, ligated infants had greater odds for major morbidities (OR 2.09, 95% CI 1.44-3.04) and 2-year neurodevelopmental impairment (OR 1.81, 95% CI 1.15-2.84). Mortality was comparable after restricting the cohort to infants surviving at least until day 10 to avoid survival bias. In the "low" group, 34 (4.9%) of 696 infants were ligated compared with 122 (17.6%) of 693 infants in the "high" group. Infants in the "high" group had greater odds for major morbidities (OR 1.49, 95% CI 1.11-2.0).

CONCLUSIONS

Our analysis identified a burden on infants receiving surgical ligation vs pharmacologic treatment in a population-based setting where there was no agreed-on common procedure. These results may guide a revision of patent ductus arteriosus treatment practice in Switzerland.

Trends in patent ductus arteriosus ligation in neonates and changes in outcomes: A 10-year multicenter experience

RATIONALE

The management of neonates with patent ductus arteriosus (PDA) has changed over time.

METHODS

We conducted a single-city, retrospective review of neonates who underwent PDA ligation over a 10-year time period and compared infants from the first 5 years to the second 5 years to evaluate how clinical characteristics changed over this time.

RESULTS

Infants from the second 5-year epoch were older at time of ligation (38 vs. 30 days), had a higher ligation weight (1432 vs. 1121 g) and a lower incidence of postligation cardiac syndrome (1.9% vs. 11.5%). No differences in mortality, length of hospital-stay or major morbidities were seen. Compared to neonates who underwent PDA ligation at ≤28 days of life, those with a ligation age >28 days had a higher ligation weight (1421 vs. 1039 g), a higher proportion of COX inhibitor use (92.5% vs. 83.8%), and a higher incidence of moderate-severe bronchopulmonary dysplasia (BPD) (60.4% vs. 44.4%). Only 10.7% (25/233) patients were evaluated by laryngoscopy, in which the incidence of vocal cord paralysis (VCP) was 36.0%; 2 patients were clinically diagnosed with VCP for a total 4.7% incidence of VCP (11/233).

CONCLUSIONS

Over the 10 years examined, neonates underwent PDA ligation at an older age in the second 5-year time period; this change was not associated with a change in the incidence of major morbidities. Ligation age >28 days was associated with an increase incidence of moderate-severe BPD. The overall incidence of documented VCP post-PDA ligation was relatively low but was seen in over 1/3 who were evaluated by laryngoscopy.

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.

Percutaneous Closure of the Patent Ductus Arteriosus in Very-Low-Weight Infants

In view of the known complications of drug therapy and open surgical ligation, and the potential for prolonged patent ductus arteriosus (PDA) exposure to be harmful, health care practitioners have sought new approaches to achieve definitive ductal closure. Interest in percutaneous (catheter-based) PDA closure has emerged within the neonatal community as a viable treatment option, because it has been fueled by recent procedural and device modifications, as well as mounting feasibility and safety data. Herein, we provide a contemporary review of percutaneous PDA closure among infants at the crux of the medical debate-very-low-weight infants (≤1,500 g), including: 1) characterization of traditional PDA treatments (drug therapy, open surgical ligation) and conservative (nonintervention) management options; 2) a general overview of the major procedural steps of percutaneous ductal closure, including efforts to reduce thrombotic complications and the emergence of a novel US Food and Drug Administration-approved device; 3) a systematic review and meta-analysis to better understand risk profiles of percutaneous PDA closure in this population; and 4) discussion of current gaps in our understanding of optimal PDA care, including the critical need for well-designed, randomized, controlled clinical trials.

Relationship of Patent Ductus Arteriosus Echocardiographic Markers With Descending Aorta Diastolic Flow

OBJECTIVES

To characterize the relationship of echocardiographic markers of left heart overload and flow in peripheral major end-organ vessels (eg, celiac artery) with the presence of reversed holodiastolic flow in the descending aorta, considered a surrogate marker of an increased transductal shunt volume, in preterm patients with a patent ductus arteriosus (PDA).

METHODS

This work was a retrospective study of data from echocardiography performed to investigate the hemodynamic significance of a PDA in preterm patients. We studied differences in echocardiographic markers of the PDA shunt volume according to patterns of flow in the postductal descending aorta (no PDA, PDA with antegrade diastolic flow, and PDA with reversed diastolic flow). The strength of the association between each echocardiographic marker and the presence of aortic holodiastolic flow reversal was investigated.

RESULTS

We studied 137 patients with a median (interquartile range) birth weight of 850 (694-1030) g and a median gestational age of 25 (24-27) weeks. Among patients with a PDA (113), those with diastolic flow reversal in the descending aorta (44) presented had increased echocardiographic markers representative of the shunt volume (increased left ventricular output, left atrial-to-aortic ratio, pulmonary vein D wave, and shorter isovolumic relaxation time) compared to those with aortic antegrade diastolic flow. A positive, albeit weak, correlation between diastolic flow reversal and shunt volume echocardiographic markers was found. Abnormal diastolic flow in the celiac artery had the strongest correlation (R²  = 0.24).

CONCLUSIONS

In preterm patients with a PDA, echocardiographic markers of the shunt volume were more abnormal in patients with reversed diastolic flow in the descending aorta. These data support the assumption that variance in these markers are related to the shunt volume, which needs consideration when adjudicating hemodynamic significance.

Outcomes of Extremely Premature Infants Comparing Patent Ductus Arteriosus Management Approaches

OBJECTIVE

To evaluate the change in the proportion of deaths/bronchopulmonary dysplasia (BPD) among premature infants (born <26 and 26-29 weeks of gestational age) following a policy change to a strict nonintervention approach, compared with standard treatment.

STUDY DESIGN

We examined 1249 infants (341 born <26 weeks of gestational age) at 2 comparable sites. Site 1 (control) continued medical treatment/ligation, and site 2 (exposed) changed to a nonintervention policy in late 2013. Using the difference-in-differences approach, which accounts for time-invariant differences between sites and secular trends, we assessed changes in death or BPD separately among infants born 26-29 weeks and <26 weeks of gestational age in 2 epochs (epoch 1: 2011-2013; epoch 2: 2014-2017).

RESULTS

Baseline characteristics were similar across sites and epochs. Medical treatment/ligation use remained stable at site 1 but declined progressively to 0% at site 2, indicating adherence to policy. We saw no difference in death/BPD among infants born at 26-29 weeks of gestational age (12%, 95% CI -1% to 24%). However, incidence of death/BPD increased by 31% among infants born <26 weeks of gestational age (95% CI 10%-51%) in site 2, whereas there was no change in outcomes in site 1. The Score for Neonatal Acute Physiology-Version II, used as a control outcome, did not change in either site, suggesting that our findings were not due to changes in patients' severity.

CONCLUSIONS

Adherence to a strict conservative policy did not impact death or BPD among 26 weeks but was associated with a significant rise in infants born <26 weeks.

Echocardiographic versus Angiographic Measurement of the Patent Ductus Arteriosus in Extremely Low Birth Weight Infants and the Utility of Echo Guidance for Transcatheter Closure

BACKGROUND

Transthoracic echocardiography (TTE) is increasingly utilized for guiding transcatheter closure of patent ductus arteriosus (PDA) in extremely low birth weight (ELBW) infants. The objectives of this study were to compare PDA size measurements by TTE with angiographic measurements and to describe TTE techniques used in guiding transcatheter PDA closure (TCPC) in ELBW infants.

METHODS

One hundred twenty-five consecutive ELBW infants (gestational age < 27 weeks, birth weight < 1 kg) who underwent TCPC before 8 weeks of age under TTE guidance were included. Patent ductus arteriosus sizes were measured from the procedural TTE and angiograms retrospectively by blinded observers. The TTE PDA diameters at the aortic (ED1) and pulmonary end (ED2) were compared with the corresponding angiographic diameters (CD1 and CD2). The TTE PDA lengths, obtained by two techniques (EL1, a straight line between ED1 and ED2; and EL2, a curvilinear line along the PDA), were compared with the PDA length by angiography (CL). Transthoracic echocardiography was used to guide accurate device positioning within the PDA.

RESULTS

The procedure weight was 600-1,460 g. The TTE and angiographic PDA diameters were comparable (mean ED1 vs CD1 = 4.5 ± 0.68 vs 4.4 ± 0.85 mm, P = .26; and mean ED2 vs CD2 = 3.1 ± 0.72 vs 3.2 ± 0.94 mm, P = .14). The angiographic length was underestimated by EL1 by 2.6 ± 1.6 mm (P < .0001), while EL2 estimated it better (mean EL2 vs CL = 11.0 ± 1.83 vs 10.8 ± 2.15 mm; P = .40). Transcatheter PDA closure was successful in 100% of the cases using TTE guidance. There were no intraprocedural complications.

CONCLUSIONS

Transthoracic echocardiography guidance during TCPC in ELBW infants eliminates the need for aortograms via femoral arterial access, preventing the complications associated with it. Transthoracic echocardiography PDA measurements are comparable to angiographic measurements, thereby assisting in appropriate device size selection.

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

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

Acetaminophen Therapy for Persistent Patent Ductus Arteriosus

Persistence of a left-to-right shunt caused by a patent ductus arteriosus (PDA) leads to significant sequelae in extremely premature infants as a result of pulmonary overcirculation and systemic steal. Although timing and duration of treatment for a persistent clinically significant PDA differ among institutions, standard pharmacologic interventions are the nonsteroidal anti-inflammatory drugs indomethacin and ibuprofen. Acetaminophen has emerged as an alternative to indomethacin and ibuprofen with less significant adverse effects, but there is no consensus regarding its use. This review summarizes the most recent evidence for the use of acetaminophen in PDA treatment.