Covariation of Neonatal Intensive Care Unit-Level Patent Ductus Arteriosus Management and In-Neonatal Intensive Care Unit Outcomes Following Preterm Birth

Evaluation of the association between patent ductus arteriosus approach and neurodevelopment in extremely preterm infants

OBJECTIVE

Assess if unit-level PDA management correlates with neurodevelopmental impairment (NDI) at 18-24 months corrected postnatal age (CPA) in extremely preterm infants.

STUDY DESIGN

Retrospective analysis of infants born at <29 weeks (2014-2017) across two units having distinct PDA strategies. Site 1 utilized an echocardiography-based treatment strategy aiming for accelerated closure (control). Site 2 followed a conservative approach.

PRIMARY ENDPOINT

NDI, characterized by cerebral palsy, any Bayley-III composite score <85, sensorineural/mixed hearing loss, or at least unilateral visual impairment.

RESULTS

377 infants were evaluated. PDA treatment rates remained unchanged in Site 1 but eventually reached 0% in Site 2. Comparable rates of any/significant NDI were seen across both sites (any NDI: 38% vs 36%; significant NDI: 13% vs 10% for Site 1 and 2, respectively). After adjustments, NDI rates remained similar.

CONCLUSION

PDA management strategies in extremely preterm newborns showed no significant impact on neurodevelopment outcomes at 18-24 months CPA.

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.

Percutaneous Closure of the Patent Ductus Arteriosus in Infants ≤2 kg: IMPACT Registry Insights

OBJECTIVES

Percutaneous patent ductus arteriosus (PDA) closure is becoming the standard of care for definitive closure in progressively smaller and younger neonates. The objective of this study was to assess safety and feasibility of percutaneous PDA closure in patients ≤2 kg.

METHODS

This was a cohort study using the IMPACT Registry (Improving Pediatric and Adult Congenital Treatments) from the American College of Cardiology Foundation's National Cardiovascular Data Registry. Patients who were ≤2 kg at the time of percutaneous PDA closure were included. The primary outcome was the composite of technical failure and/or major adverse event.

RESULTS

A total of 1587 attempted PDA closures were included, with a 3% incidence of technical failure and 5.5% incidence of the composite outcome. Major adverse events were observed in 3.8% of the patients; the most common events were device embolization requiring retrieval and unplanned cardiac or vascular surgery in 1.3% and 1.3% of cases, respectively. The incidence of the composite outcome was associated with the need for arterial access (P < .001) as well as annual hospital volume of percutaneous PDA closures in infants ≤2 kg (P = .001). The incidence of the composite outcome has decreased overtime, whereas median weight at the time of procedure has also diminished.

CONCLUSIONS

Percutaneous PDA closure appears to be safe and feasible procedures in infants ≤2 kg. The incidence of major adverse events has continued to decline over the years and seems to have a strong correlation with individual center case volumes and expertise.

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.

Does active treatment in infants born at 22-23 weeks correlate with outcomes of more mature infants at the same hospital? An analysis of California NICU data, 2015-2019

OBJECTIVE

To investigate whether hospital rates of active treatment for infants born at 22-23 weeks is associated with survival of infants born at 24-27 weeks.

STUDY DESIGN

We included all liveborn infants 22-27 weeks of gestation delivered at California Perinatal Quality Care Collaborative hospitals from 2015 to 2019. We assessed (1) the correlation of active treatment (e.g., endotracheal intubation, epinephrine) in 22-23 week infants and survival until discharge for 24-27 week infants and (2) the association of active treatment with survival using multilevel models.

RESULT

The 22-23 week active treatment rate was associated with infant outcomes at 22-23 weeks but not 24-27 weeks. A 10% increase in active treatment did not relate to 24-25 week (adjusted OR: 1.00 [95% CI: 0.95-1.05]), or 26-27 week survival (aOR: 1.02 [0.95-1.09]).

CONCLUSION

The hospital rate of active treatment for infants born at 22-23 weeks was not associated with improved survival for 24-27 week infants.

Effects of prophylactic indomethacin on morbidity and mortality in infants <25 weeks' gestation: a protocol driven intention to treat analysis

OBJECTIVE

To determine if prophylactic indomethacin (PINDO) decreases death or bronchopulmonary dysplasia-grades 2 and 3 (death/BPD) in newborns <25 weeks.

STUDY DESIGN

Intention-to-treat, cohort-controlled study of 106 infants admitted during three alternating epochs of PINDO or Expectant patent ductus arteriosus (PDA) management.

RESULTS

At 7-8 days 85% of Expectant Management epoch infants had a moderate/large PDA (median exposure was 23 days). Among PINDO epoch infants only 24% still had a PDA at 7-8 days. There were no significant differences in the incidence of death/BPD or of secondary outcomes (BPD, death, necrotizing enterocolitis/spontaneous perforations, or intraventricular hemorrhage (grades 3 or 4)) in either unadjusted or adjusted comparisons between infants born in a PINDO epoch and those born in the Expectant Management epoch.

CONCLUSION

Despite being at high risk for PDA-related morbidities, PINDO did not appear to alter the rates of our primary and secondary outcomes in infants <25 weeks.

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.

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.

Rates of Bronchopulmonary Dysplasia Following Implementation of a Novel Prevention Bundle

IMPORTANCE

Bronchopulmonary dysplasia (BPD) rates in the United States remain high and have changed little in the last decade.

OBJECTIVE

To develop a consistent BPD prevention bundle in a systematic approach to decrease BPD.

DESIGN, SETTING, AND PARTICIPANTS

This quality improvement study included 484 infants with birth weights from 501 to 1500 g admitted to a level 3 neonatal intensive care unit in the Kaiser Permanente Southern California system from 2009 through 2019. The study period was divided into 3 periods: 1, baseline (2009); 2, initial changes based on ongoing cycles of Plan-Do-Study-Act (2010-2014); and 3, full implementation of successive Plan-Do-Study-Act results (2015-2019).

INTERVENTIONS

A BPD prevention system of care bundle evolved with a shared mental model that BPD is avoidable.

MAIN OUTCOMES AND MEASURES

The primary outcome was BPD in infants with less than 33 weeks' gestational age (hereafter referred to as BPD <33). Other measures included adjusted BPD <33, BPD severity grade, and adjusted median postmenstrual age (PMA) at hospital discharge. Balancing measures were adjusted mortality and adjusted mortality or specified morbidities.

RESULTS

The study population included 484 infants with a mean (SD) birth weight of 1070 (277) g; a mean (SD) gestational age of 28.6 (2.9) weeks; 252 female infants (52.1%); and 61 Black infants (12.6%). During the 3 study periods, BPD <33 decreased from 9 of 29 patients (31.0%) to 3 of 184 patients (1.6%) (P < .001 for trend); special cause variation was observed. The standardized morbidity ratio for the adjusted BPD <33 decreased from 1.2 (95% CI, 0.7-1.9) in 2009 to 0.4 (95% CI, 0.2-0.8) in 2019. The rates of combined grades 1, 2, and 3 BPD decreased from 7 of 29 patients (24.1%) to 17 of 183 patients (9.3%) (P < .008 for trend). Grade 2 BPD rates decreased from 3 of 29 patients (10.3%) to 5 of 183 patients (2.7%) (P = .02 for trend). Adjusted median PMA at home discharge decreased by 2 weeks, from 38.2 (95% CI, 37.3-39.1) weeks in 2009 to 36.8 (95% CI, 36.6-37.1) weeks during the last 3 years (2017-2019) of the full implementation period. Adjusted mortality was unchanged, whereas adjusted mortality or specified morbidities decreased significantly.

CONCLUSIONS AND RELEVANCE

A sustained low rate of BPD was observed in infants after the implementation of a detailed BPD system of care.

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.

Outcomes in infants < 29 weeks of gestation following single-dose prophylactic indomethacin

BACKGROUND

Prophylactic indomethacin (3 doses) decreases patent ductus arteriosus (PDA) and intraventricular hemorrhage (IVH) in preterm infants. The study aim was to determine whether single-dose indomethacin (SD-INDO) decreases PDA, IVH, and improves motor function.

METHODS

A retrospective cohort (2007-2014) compared infants born < 29 weeks who did (n = 299) or did not (n = 85) receive SD-INDO and estimated outcomes association with ordinal logistic regression, adjusting for multiple variables using propensity scores.

RESULTS

Infants who received SD-INDO were more premature (p < 0.001) but had lower odds of PDA (OR 0.26 [0.15, 0.44], p < 0.005), PDA receiving treatment (OR 0.12 [0.03, 0.47], p < 0.005), death (OR 0.41 [0.20, 0.86], p = 0.02), and CP severity (OR 0.33 [0.12, 0.89], p = 0.03). There was less IVH (OR 0.58 [0.36, 0.94], p = 0.03) when adjusted for gestational age.

CONCLUSIONS

SD-INDO is associated with decreased PDA and CP severity and improved survival.

Does crossover treatment of control subjects invalidate results of randomized trials of patent ductus arteriosus treatment?

Optimal management of patent ductus arteriosus (PDA) in extremely preterm infants remains controversial. There is paucity of evidence on the benefits of PDA treatment in reducing mortality and morbidities in extremely preterm infants. Failure of randomized clinical trials to demonstrate beneficial effects of PDA treatment on outcomes has often been attributed to open treatment of control subjects. This perspective examines the PDA treatment trials to date, with specific focus on rates of and ages of subjects at open rescue treatment. Although these trials demonstrate that ductal closure is significantly increased with treatment, that does not translate to a significant decrease in major morbidities or mortality in premature infants, even when trials with high rates of rescue treatment of controls are excluded. Trials in which enrollment occurred after 7 days of age include insufficient numbers of subjects to evaluate this relationship.

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.

Patent ductus arteriosus and cerebral, cardiac, and gut hemodynamics in premature neonates

Patent ductus arteriosus is associated with multiple comorbidities in premature infants, however a causal link or strategy to decrease these morbidities has not been found. The association between the patent ductus arteriosus and morbidities has biologic plausibility as, like any cardiac mixing lesion, a significant systemic to pulmonic shunt may lead to pulmonary over-circulation and systemic hypoperfusion. Understanding the underlying pathophysiology of associated morbidities in the setting of a patent ductus arteriosus may aid in risk stratifying infants and offer a patient targeted approach to infants with a pathological ductal shunt. While the deleterious impact of increased pulmonary blood flow maybe easier to identify, the impact on end-organ perfusion is more challenging. In this review, we will discuss the pathophysiology of a hemodynamically significant patent ductus arteriosus in premature infants, impact on end-organ perfusion and associated morbidities, and novel modalities to assess shunt volume and effect on end-organ perfusion.

Effect of Nonintervention vs Oral Ibuprofen in Patent Ductus Arteriosus in Preterm Infants: A Randomized Clinical Trial

IMPORTANCE

Persistent patent ductus arteriosus (PDA) in preterm infants is associated with increased mortality and respiratory morbidities, including bronchopulmonary dysplasia (BPD). Despite recent increasing use of noninterventional approaches, no study to our knowledge has yet directly compared the nonintervention vs pharmacologic treatment for mediating PDA closure for decreasing mortality and preventing BPD.

OBJECTIVE

To determine the noninferiority of nonintervention vs oral ibuprofen treatment for PDA in decreasing BPD incidence or death in very preterm infants.

DESIGN, SETTING, AND PARTICIPANTS

A randomized, double-blind, placebo-controlled, noninferiority clinical trial was conducted on preterm infants (gestational age [GA] 23-30 weeks) with hemodynamically significant PDA (ductal size >1.5 mm plus respiratory support) diagnosed between postnatal days 6 and 14. Participants included 383 infants screened between July 24, 2014, and March 15, 2019.

INTERVENTIONS

Infants were stratified by GA and randomly assigned (1:1) to receive either oral ibuprofen (initial dose of 10 mg/kg followed by a 5-mg/kg dose after 24 hours and a second 5-mg/kg dose after 48 hours) or placebo.

MAIN OUTCOMES AND MEASURES

The primary outcome was BPD or death; the secondary outcomes included major morbidities and ductal closure rates. Per-protocol analysis was used.

RESULTS

Among 383 infants screened for participation, 146 infants were randomly assigned, with 72 in the nonintervention and 70 in the ibuprofen treatment group in the final analyses. The PDA closure rate at 1 week after randomization was significantly higher with ibuprofen (11 [34%]) than nonintervention (2 [7%]) in infants at GA 27 to 30 weeks (P = .007); however, the findings were not significant at GA 23 to 26 weeks (ibuprofen, 3 [8%] vs nonintervention, 1 [2%], P = .34). In addition, the ductal closure rates before hospital discharge (ibuprofen, 62 [89%] vs nonintervention, 59 [82%], P = .27) and device closure (ibuprofen, 2 [3%] vs nonintervention, 4 [6%], P = .40) were not significantly different between the 2 groups. The nonintervention approach was noninferior to ibuprofen treatment in terms of BPD incidence or death (nonintervention, 44%; ibuprofen, 50%; 95% CI, -0.11 to 0.22; noninferiority margin -0.2; P = .51). One infant in the ibuprofen arm received oral ibuprofen backup rescue treatment owing to cardiopulmonary compromise refractory to conservative management, and another infant in the ibuprofen group received surgical ligation; none of the infants in the placebo group received backup treatment.

CONCLUSIONS AND RELEVANCE

Nonintervention showed noninferiority compared with ibuprofen treatment in closing of hemodynamically significant PDA and reduction of BPD or death. The noninferiority of nonintervention over ibuprofen might be attributable to the low efficacy of oral ibuprofen for closing PDA, especially in infants born at 23 to 26 weeks' gestation.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02128191.

The optimal timing of surgical ligation of patent ductus arteriosus in preterm or very-low-birth-weight infants: A systematic review and meta-analysis

BACKGROUND

Patent ductus arteriosus (PDA) is a particularly common problem in preterm infants. Although surgical ligation is rarely performed in many contemporary neonatal intensive care units, it remains a necessary treatment option for preterm infants with a large hemodynamically significant PDA under strict clinical criteria, and it can reduce mortality in preterm infants. However, the optimal timing of surgical ligation is still controversial. We conducted this systematic review and meta-analysis to compare the mortality and morbidity of early and late surgical ligation of PDA in preterm or very-low-birth-weight (VLBW) infants.

METHODS

This review was registered in the International Prospective Register of Systematic Reviews (PROSPERO) (CRD42019133686). We searched the databases of PubMed, Embase, the Cochrane Central Register of Controlled Trials, and the World Health Organization International Clinical Trials Registry Platform up to May 2019.

RESULTS

This review included 6 retrospective studies involving 397 premature or VLBW infants with PDA. Pooled analysis showed that compared with the late ligation group, the early ligation group had a lower fraction of inspired oxygen (FiO2) at 24 hours postoperatively (mean difference [MD] -6.34, 95% confidence interval [CI] -9.45 to -3.22), fewer intubation days (MD -19.69, 95% CI -29.31 to -10.07), earlier date of full oral feeding (MD -22.98, 95% CI -28.63 to -17.34) and heavier body weight at 36 weeks of conceptional age (MD 232.08, 95% CI 57.28 to 406.88). No significant difference in mortality or other complications was found between the early and late groups.

CONCLUSION

Our meta-analysis implies that compared with late surgical ligation, early ligation might have a better respiratory outcome and nutritional status for PDA in preterm or VLBW infants. There was no difference in mortality or postoperative complications between early and late ligation. A randomized prospective clinical trial with a possible large sample size is urgently needed to reinvestigate this conclusion.

PROSPERO REGISTRATION NUMBER

CRD42019133686.

Selective Treatment of PDA in High-Risk VLBW Infants With Birth Weight ≤800 g or <27 Weeks and Short-Term Outcome: A Cohort Study

Background: Patent ductus arteriosus (PDA) causing significant left to right shunt can increase key morbidities in preterm infants. Yet, treatment does not improve outcomes and spontaneous closure is the natural course of PDA. The Impact of PDA on 23-26-week gestation infants is uncertain. Selective treatment of such infants would likely balance outcomes. Objective: To test the hypothesis that treatment of PDA in high-risk VLBW infants [birth weight ≤800 g or gestation <27 weeks, hemodynamically significant, ductal diameter (DD, ≥1.6 mm), and mechanical ventilation] and expectant management in low-risk infants will reduce the need for treatment and surgical ligation, without altering short term morbidities. Methods: This prospective observational study was initiated subsequent to the introduction of a new treatment protocol in 2016. The 12-months before and after protocol introduction were, respectively, defined as standard and early selective treatment periods. In the early selective treatment cohort, PDA was treated with indomethacin, maximum of two courses, 1 week apart. Surgical ligation was considered after 30 days of age if indicated (DD ≥2 mm, mechanical ventilation). Primary outcomes were need for treatment and rate of ligation. Protocol compliance and secondary outcomes were documented. Results: 415 infants were studied, 202 and 213 in the standard treatment and early selective treatment cohorts, respectively. Numbers treated (per protocol) in the standard treatment and early selective treatment cohorts were 27.7 and 19.3% (56/202 and 41/213) (p = 0.049), and the respective ligation rates were 7.54 and 2.96% (P = 0.045). Secondary outcomes were comparable. Conclusion: The early selective treatment protocol reduced the rates of treatment and surgical ligation of PDA, without altering key morbidities. Further studies under a randomized control trial setting is warranted.

Conservative Non-intervention Approach for Hemodynamically Significant Patent Ductus Arteriosus in Extremely Preterm Infants

While persistent patent ductus arteriosus (PDA) in preterm infants has been known to be associated with increased mortality and morbidities including bronchopulmonary dysplasia, and necrotizing enterocolitis, there is minimal evidence supporting their causal relationships, and most traditional medical and/or surgical treatments have failed to show improvements in these outcomes. As such, the pendulum has swung toward the conservative non-intervention approach for the management of persistent PDA during the last decade; however, the benefits and risks of this approach are unclear. In this mini review, we focused on whom, when, and how to apply the conservative non-intervention approach for persistent PDA, especially in extremely preterm infants.

Lack of Equipoise in the PDA-TOLERATE Trial: A Comparison of Eligible Infants Enrolled in the Trial and Those Treated Outside the Trial

The PDA: TO LEave it alone or Respond And Treat Early trial compared the effects of 2 strategies for treatment of patent ductus arteriosus (PDA) in infants <28^0/7 weeks of gestation; however 137 potentially eligible infants were not recruited and received treatment of their PDA outside the PDA-TOLERATE trial due to "lack-of-physician-equipoise" (LPE). Despite being less mature and needing more respiratory support, infants with LPE had lower rates of mortality than enrolled infants. Infants with LPE treated before day 6 had lower rates of late respiratory morbidity than infants with LPE treated ≥day 6. TRIAL REGISTRATION: ClinicalTrials.gov: NCT01958320.

Regional tissue oxygenation monitoring in the neonatal intensive care unit: evidence for clinical strategies and future directions

Near-infrared spectroscopy (NIRS)-based monitoring of regional tissue oxygenation (rSO₂) is becoming more commonplace in the neonatal intensive care unit (NICU). While increasing evidence supports rSO₂ monitoring, actual standards for applying this noninvasive bedside technique continue to evolve. This review highlights the current strengths and pitfalls surrounding practical NIRS-based monitoring in the neonatal population. The physiologic background of rSO₂ monitoring is discussed, with attention to understanding oxygen delivery/consumption mismatch and its effects on tissue oxygen extraction. The bedside utility of both cerebral and peripheral rSO₂ monitoring in the NICU is then explored from two perspectives: (1) disease/event-specific "responsive" monitoring and (2) "routine," continuous monitoring. Recent evidence incorporating both monitoring approaches is summarized with emphasis on practical applicability in the NICU. Finally, a future paradigm for a broad-based NIRS monitoring strategy is presented, with attention towards improving personalization of neonatal care and ultimately enhancing long-term outcomes.

CYP2C9*2 is associated with indomethacin treatment failure for patent ductus arteriosus

Aims: To identify clinical andgenetic factors associated with indomethacin treatment failure in preterm neonates with patent ductus arteriosus (PDA). Patients & Methods: This is a multicenter cohort study of 144 preterm infants (22-32 weeks gestational age) at three centers who received at least one treatment course of indomethacin for PDA. Indomethacin failure was defined as requiring subsequent surgical intervention. Results: In multivariate analysis, gestational age (AOR 0.76, 95% CI 0.60-0.96), surfactant use (AOR 9.77, 95% CI 1.15-83.26), and CYP2C9*2 (AOR 3.74; 95% CI 1.34-10.44) were each associated with indomethacin failure. Conclusion: Age, surfactant use, and CYP2C9*2 influence indomethacin treatment outcome in preterm infants with PDA. This combination of clinical and genetic factors may facilitate targeted indomethacin use for PDA.

Practice for preterm patent ductus arteriosus; focusing on the hemodynamic significance and the impact on the neonatal outcomes

Hemodynamically significant preterm patent ductus arteriosus (PDA) affects mortality; comorbidities such as necrotizing enterocolitis, intraventricular hemorrhage, and bronchopulmonary dysplasia; and adverse long-term neurodevelopmental outcomes in preterm infants, particularly in very low birth weight infants. However, recent studies have indicated that there is no consensus on the causal relationship between PDA and neonatal outcomes, the benefit of PDA treatment, the factors guiding the need for treatment, and optimal treatment strategies. Such uncertainty has resulted in wide variations in practice for treating preterm PDA between units, regions, and nations. Nowadays, there has been a paradigm shift to more conservative treatment for preterm PDA, and suggestions regarding selective management of preterm PDA considering risk factors and hemodynamic significance are increasing. Neonatologist-performed echocardiography and advances in modalities to assess hemodynamic significance such as biologic markers and near-infrared spectroscopy also help improve the efficacy of selective treatment of preterm PDA.