Preterm patent ductus arteriosus: A continuing conundrum for the neonatologist?

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.).

NT-PROBNP as a screening tool for low-risk patent ductus arteriousus: a follow-up validation study

The purpose of the study is to test whether NT-proBNP serves as a screening tool for low-risk patent ductus arteriosus and safely avoids routine early echocardiography. This is a prospective observational study in preterm infants ≤32 weeks of gestational age. Infants with ≥5100 pg/ml (positive screening) at 48-72 hours of life received comprehensive echocardiography and were treated according to shunt severity. Infants with NT-proBNP below 5100 pg/ml (negative screening) were managed expectantly. The main outcome was need for ductus treatment within the first 7 days of life. One hundred twenty-five infants were included; 82 had a negative NT-proBNP screening and 43 had a positive NT-proBNP screening. No infant (0%) with a negative screening was treated for ductus while 26 (60.4%) with a positive screening were treated (p < 0.001). NT-proBNP avoided a 65.6% of routine echocardiograms. NT-proBNP had an excellent performance to predict PDA treatment (AUC = 0.967).Conclusion: NT-proBNP at 48-72 hours of life has an excellent performance to detect low risk and avoids unnecessary echocardiograms. This may contribute to optimize PDA management in terms of resource utilization.

Perioperative anesthetic management of premature neonates weighing less than 1500 grams undergoing transcatheter PDA (TC-PDA) closure: An institutional anesthetic experience

Objectives

The aim of our study is to describe the various anesthetic techniques and intraoperative management used during transcatheter closure of hemodynamically significant PDAs in VLBW premature infants weighing less than 1.5 kg and their potential impact on postoperative outcomes using a retrospective chart review.

Design

A retrospective electronic medical chart review was performed in infants who underwent Transcatheter Patent Ductus Arteriosus (TC-PDA) closure at an academic institution between January 1, 2008 and October 4th 2019. Only premature patients with isolated PDA weighing less than 1500 g at the time of the procedure were included in the study.

Setting

Single Institutional Hospital.

Participants

Premature patients with isolated PDA weighing less than 1500 g at the time of the procedure.

Interventions

None.

Measurements and main results

Interprocedurally, there was no evidence of device embolization or clinically significant vascular obstruction on follow-up echocardiography, and inotropic or vasoactive infusions were not required. All patients survived and were discharged from the hospital after a mean of 86.4 ± 48.49 days (median 74, range 40-180) following initial admission to the NICU. At 7 post-operative days, freedom from ventilatory support reached 70% in all patients. Incidences of device embolization or clinically significant vascular obstruction were not noted on follow-up echocardiography.

Conclusions

Though our preliminary findings show promising outcomes following TC-PDA closure relative to traditional surgical approaches, further investigations with higher patient volume are needed to validate these promising observations.

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.

The Association of Patent Ductus Arteriosus with Inflammation: A Narrative Review of the Role of Inflammatory Biomarkers and Treatment Strategy in Premature Infants

Patent ductus arteriosus (PDA) is a common cardiovascular complication that complicates clinical care in the intensive care of premature infants. Prenatal and postnatal infections and the inflammation process can contribute to PDA, and intrauterine inflammation is a known risk factor of PDA. A variety of inflammatory biomarkers have been reported to be associated with PDA. Chorioamnionitis induces the fetal inflammatory process via several cytokines that have been reported to be associated with the presence of PDA and may have a role in the vascular remodeling process or vessel dilation of the ductus. On the other hand, anti-inflammatory agents, such as antenatal steroids, decrease PDA incidence and severity in patients born to those with chorioamnionitis. Proinflammatory cytokines, which are expressed more significantly in preterm neonates and chorioamnionitis, are associated with the presence of PDA. In this review, we focus on the pathogenesis of PDA in preterm infants and the role of biomarkers associated with the perinatal inflammatory process.

Acute liver failure secondary to therapeutic paracetamol dosing in an extremely preterm neonate

We report the first case of standard therapeutic dose paracetamol for patent ductus arteriosus closure causing acute liver failure in an extremely preterm infant. After 5 days of treatment, he presented with jaundice, acute severe hepatitis and coagulopathy. Treatment with N-acetyl cysteine resulted in full recovery.

International Variation in the Management of Patent Ductus Arteriosus and Its Association with Infant Outcomes: A Survey and Linked Cohort Study

OBJECTIVE

To assess whether treating patients with a presymptomatic patent ductus arteriosus (PDA), based on early routine echocardiography, performed regardless of clinical signs, improved outcomes.

STUDY DESIGN

This multicenter, survey-linked retrospective cohort study used an institutional-level questionnaire and individual patient-level data and included infants of <29 weeks of gestation born in 2014-2016 and admitted to tertiary neonatal intensive care units (NICUs) of 9 population-based national or regional neonatal networks. Infants in NICUs receiving treatment of presymptomatic PDA identified by routine echocardiography and those not were compared for the primary composite outcome (early death [≤7 days after birth] or severe intraventricular hemorrhage) and secondary outcomes (any in-hospital mortality and major morbidities).

RESULTS

The unit survey (response rates of 86%) revealed a wide variation among networks in the treatment of presymptomatic PDA (7%-86%). Among 246 NICUs with 17 936 infants (mean gestational age of 26 weeks), 126 NICUs (51%) with 7785 infants treated presymptomatic PDA. The primary outcome of early death or severe intraventricular hemorrhage was not significantly different between the NICUs treating presymptomatic PDA and those who did not (17% vs 21%; aOR 1.00, 95% CI 0.85-1.18). The NICUs treating presymptomatic PDA had greater odds of retinopathy of prematurity treatment (13% vs 7%; aOR 1.47, 95% CI 1.01-2.12); however, it was not significant in a sensitivity analysis excluding Japanese data.

CONCLUSIONS

Treating presymptomatic PDA detected by routine echocardiography was commonplace but associated with no significant benefits. Well-designed trials are needed to assess the efficacy and safety of early targeted PDA treatment.

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.

Mouse models of patent ductus arteriosus (PDA) and their relevance for human PDA

The ductus arteriosus (DA) is a unique fetal vascular shunt, which allows blood to bypass the developing lungs in utero. After birth, changes in complex signaling pathways lead to constriction and permanent closure of the DA. The persistent patency of the DA (PDA) is a common disorder in preterm infants, yet the underlying causes of PDA are not fully defined. Although limits on the availability of human DA tissues prevent comprehensive studies on the mechanisms of DA function, mouse models have been developed that reveal critical pathways in DA regulation. Over 20 different transgenic models of PDA in mice have been described, with implications for human DA biology. Similarly, we enumerate 224 human single-gene syndromes that are associated with PDA, including a small subset that consistently feature PDA as a prominent phenotype. Comparison and functional analyses of these genes provide insight into DA development and identify key regulatory pathways that may serve as potential therapeutic targets for the management of PDA.

Management of patent ductus arteriosus in very preterm infants in England and Wales: a retrospective cohort study

OBJECTIVE

To describe the diagnosis and treatment of patent ductus arteriosus (PDA) in infants born at <32 weeks' gestational age (GA) in England and Wales between 2010 and 2017.

STUDY DESIGN

Retrospective cohort study using routinely recorded data from the National Neonatal Research Database of infants born at <32 weeks admitted to neonatal units in England and Wales from 2010 to 2017.

RESULTS

Among 58 108 infants born at <32 weeks' GA, 28.3% (n=16 440) had a PDA diagnosed clinically or with echocardiographic confirmation. Of these, 34.8% (n=5721; 9.8% of total <32 weeks' infants included) had PDA treatment including 7.6% (n=1255) with indomethacin, 23.5% (n=3857) with ibuprofen and 5.6% (n=916) with surgical closure. The highest incidence of PDA was among infants born at 24 and 25 weeks' GA (70.2% and 70.8%, respectively), decreasing to 6.1% among infants born at 31 weeks' GA. The percentage of infants with a PDA increased over the study period (25.5% in 2010 to 28.5% in 2017). The percentage of infants who received ibuprofen or indomethacin or had PDA surgery decreased from 41.3% in 2010 to 33.7% in 2017, with an increase in use of ibuprofen from 20.2% to 27.3% while use of indomethacin decreased from 20.0% to 8.8%. Surgical closure of PDA decreased from 9.1% to 3.0%. Indomethacin was used for median (IQR) 3 (2-5) days while ibuprofen was given for 3 (2-4) days, at a median of 8 and 10 days after birth, respectively; surgical treatment was used later at 33 (24-45) days after birth.

CONCLUSIONS

Ibuprofen is the preferred drug and surgical interventions are becoming less frequent for PDA closure among very preterm infants in England and Wales.

TRIAL REGISTRATION NUMBER

NCT03773289.

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.

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.

Early targeted patent ductus arteriosus treatment in premature neonates using a risk based severity score: study protocol for a randomised controlled trial (PDA RCT)

A patent ductus arteriosus (PDA) in preterm infants is associated with increased ventilator dependence and chronic lung disease, necrotizing enterocolitis, intraventricular haemorrhage, and poor neurodevelopmental outcome. Randomised controlled trials of early PDA treatment have not established a drop in the aforementioned morbidities. Those trials did not physiologically categorise PDA severity. Incorporating the specific physiological features of a haemodynamic significant PDA may evolve our understanding of this phenomenon, allowing accurate triaging using echocardiography and targeted treatment.  Our group has recently demonstrated that a PDA severity score (PDAsc) derived at 36-48 hours of age can accurately predict the later occurrence of chronic lung disease or death (CLD/Death). Using echocardiography, we assessed PDA characteristics, as well as left ventricular diastolic function and markers of pulmonary overcirculation, and from this formulated a PDAsc. Gestation was also incorporated into the score. We hypothesise that in preterm infants at high risk of developing CLD/Death based on a PDAsc, early treatment with Ibuprofen compared with placebo will result in a reduction in CLD/Death. This is a single centre double-blind two arm randomised controlled trial conducted in the neonatal intensive care unit in the Rotunda Hospital, Dublin. Echocardiogram is carried out in the first 36-48 hours of life to identify preterm infants with a PDAsc ≥ 5.0 and these infants are randomised to Ibuprofen or placebo. Primary outcomes are assessed at 36 weeks post menstrual age. This pilot study’s purpose is to assess the feasibility of performing the trial and to obtain preliminary data to calculate a sample size for a definitive multi-centre trial of early PDA treatment using a PDAsc. We aim to recruit a total of 60 infants with a high risk PDA over three years.

Trial Registration: ISRCTN ISRCTN13281214 (26/07/2016) and the European Union Drug Regulating Authorities Clinical Trials Database 2015-004526-33 (03/12/2015).

Early closure mechanisms of the ductus arteriosus in immature infants

AIM

According to experimental studies, cardiopulmonary distress decreases after closure of patent ductus arteriosus. However, early closure of the ductus using ibuprofen or indomethacin has failed to increase survival without serious morbidity. We review relevant data aiming to define optimal early management strategies that promote early closure of ductus arteriosus without serious adverse effects.

METHODS

Literature in English was searched selectively focusing on the potential of using acetaminophen for early closure of the ductus.

RESULTS

Prophylactic ibuprofen or indomethacin intended to close the ductus, predisposes infants to ischaemia, bleeding and immune dysfunction. Acetaminophen appears to have a similar efficacy as indomethacin or ibuprofen, and all three dose-dependently constrict the ductus. Ibuprofen and indomethacin cause non-specific inhibition of prostaglandin synthesis, while acetaminophen predominantly inhibits prostaglandin E synthesis. Owing to low CYP450 activity in infancy, acetaminophen toxicity has been rarely evident. However, increasing the dosage increases the oxidative stress. We review prophylactic treatments that may increase the safety and efficacy of acetaminophen. These include vitamin A, cysteine and glutamine, and low-dose corticosteroid supplementation.

CONCLUSION

The current challenge is to define a safe perinatal management practice that promotes cardiorespiratory adaptation in immature infants, particularly the seamless closure of the ductus before significant cardiopulmonary distress develops.

Protective factors against preterm infants to develop significant patent ductus arteriosus

BACKGROUND

Identifying preterm infants with a higher likelihood of spontaneous patent ductus arteriosus (PDA) closure would be desirable. This study aimed to examine daily PDA status during the first week of life for very low birthweight (VLBW, <1500 g) preterm infants and to develop a scoring system to predict spontaneous PDA closure.

METHODS

We enrolled VLBW infants admitted between January 2016 and January 2017 and performed daily echocardiographic screening for PDA existence. Oxygen index (OI, mean airway pressure × fraction of inspired oxygen/partial pressure of arterial oxygen) was applied to represent the respiratory condition.

RESULTS

A total of 215 VLBW infants were enrolled, and the accumulative incidence of spontaneous PDA closure by age 1 week was 80%, 70%, and 34% for infants born of gestational age (GA) ≥30, 28-29, and ≤27 weeks, respectively. Of these 215 infants, 184 infants entered the second phase to establish the scoring system. Infants with spontaneous PDA closure were more mature (GA 29.2 ± 2.3 vs. 26.9 ± 2.3 weeks, p < 0.001), had lower OI (2.8 ± 2.2 vs. 5.6 ± 5.3, p < 0.001) and were less likely to need endotracheal intubation (23% vs. 68%, p < 0.001). Using the receiver operating characteristics curve, OI <2.5 was determined favoring higher PDA closure incidence. The score was calculated based on the odds ratio generated in multiple regression: 4, 3 and 1 points for GA ≥30, 28-29 and ≤27 weeks, 2 and 1 points for OI <2.5 and ≥2.5, and 3 and 1 points for without and with endotracheal intubation. Using score ≥6 to predict PDA closure, the sensitivity and specificity were 0.77 and 0.72.

CONCLUSION

A score made up of GA, OI and need for intubation was proposed to predict spontaneous PDA closure by age 1 week, which could be helpful to clinicians in the management of PDA in preterm infants.

Effect of Early Targeted Treatment of Ductus Arteriosus with Ibuprofen on Survival Without Cerebral Palsy at 2 Years in Infants with Extreme Prematurity: A Randomized Clinical Trial

OBJECTIVE

To examine the effects of early echocardiography-targeted ibuprofen treatment of large patent ductus arteriosus (PDA) on survival without cerebral palsy at 24 months of corrected age.

STUDY DESIGN

We enrolled infants born at <28 weeks of gestation with a large PDA on echocardiography at 6-12 hours after birth to ibuprofen or placebo by 12 hours of age in a multicenter, double blind, randomized-controlled trial. Open-label ibuprofen was allowed for prespecified criteria of a hemodynamically significant PDA. The primary outcome was survival without cerebral palsy at 24 months of corrected age.

RESULTS

Among 337 enrolled infants, 109 had a small or closed ductus and constituted a reference group; 228 had a large PDA and were randomized. The primary outcome was assessed at 2 years in 108 of 114 (94.7%) and 102 of 114 (89.5%) patients allocated to ibuprofen or placebo, respectively. Survival without cerebral palsy occurred in 77 of 108 (71.3%) after ibuprofen, 73 of 102 (71.6%) after placebo (adjusted relative risk 0.98, 95% CI 0.83-1.16, P = .83), and 77 of 101 (76.2%) in reference group. Infants treated with ibuprofen had a lower incidence of PDA at day 3. Severe pulmonary hemorrhage during the first 3 days occurred in 2 of 114 (1.8%) infants treated with ibuprofen and 9 of 114 (7.9%) infants treated with placebo (adjusted relative risk 0.22, 95% CI 0.05-1.00, P = .05). Open-label rescue treatment with ibuprofen occurred in 62.3% of infants treated with placebo and 17.5% of infants treated with ibuprofen (P < .001), at a median (IQR) age of 4 (3, 5) and 4 (4, 12) days, respectively.

CONCLUSIONS

Early echocardiography-targeted ibuprofen treatment of a large PDA did not change the rate of survival without cerebral palsy.

TRIAL REGISTRATION

Eudract 2011-003063-30 and ClinicalTrials.gov: NCT01630278.

Hemodynamic support of the micropreemie: Should hydrocortisone never be left out?

Hemodynamic support for a micropreemie is critically important for preventing mortality and morbidity. An essential consideration in hemodynamic support is insufficient transition from fetal to neonatal circulation and inadequate cortisol production. The first 72 h of life are the most critical, especially when myocardial function is immature and impaired. Therefore, there is a need to determine and adjust preload, myocardial contractility, and afterload appropriately using repeated functional echocardiography. In addition, if myocardial function is not responsive to these attempts at hemodynamic management, hydrocortisone must be used to minimize the suboptimal perfusion burden. Fetal cortisol production is supported by a supply of progesterone from the placenta, and postnatally, adrenal cortisol production in the extremely preterm infant may be inadequate if the infant is placed under excessive stress. This leads to relative adrenal insufficiency which may last for up to several weeks after birth and lead to late-onset circulatory collapse, necessitating treatment with physiological doses of hydrocortisone.

Reference intervals for preterm thyroid function during the fifth to seventh day of life

BACKGROUND

Due to the lack of reference intervals for serum free triiodothyronine (FT3), free thyroxine (FT4) and thyroid stimulating hormone (TSH) in preterm neonates during the 5th to 7th day of life, we performed a retrospective study using the chemiluminescence immunoassay system.

METHODS

A total of 2040 preterm neonates with a gestational age (GA) of 26-35 weeks in the neonatal intensive care unit from 2014 to 2019 were included. Their serum FT3, FT4 and TSH values were calculated and analyzed to establish reference intervals for preterm neonates stratified by GA. The comparisons of FT3, FT4 and TSH were made by sex (males and females) and gestational age (26-28 weeks; 29-32 weeks; 33-35 weeks).

RESULTS

The reference intervals for FT3, FT4 and TSH in preterm neonates with a GA of 26-35 weeks were (1.65~5.21) pmol/L, (8.64~25.41) pmol/L, and (0.406~12.468) mlU/L, respectively. There were significant differences between serum FT3 and FT4 values and GA, while TSH levels were not significantly different (P < 0.01). The serum FT3 values of males were lower than those of females, especially in the 29-32 weeks group. No significant differences in serum values between sexes were found in FT4 or TSH (P > 0.05).

CONCLUSION

Reference intervals of thyroid function tests were established to determine the early diagnostic criteria of thyroid diseases for neonates with a GA of 26-35 weeks and to avoid unnecessary retesting and interventions. The reference intervals of FT4 can be used as an indicator to regulate the doses of thyroid hormone supplement in the treatments of congenital hypothyroidism.

Patent ductus arteriosus shunt elimination results in a reduction in adverse outcomes: a post hoc analysis of the PDA RCT cohort

OBJECTIVE

A post hoc appraisal of the PDA RCT to assess the relationship between early patent ductus arteriosus (PDA) shunt elimination and chronic lung disease or death (CLD/Death).

STUDY DESIGN

Infants <29 weeks were divided into four groups: intervention arm in whom PDA closure was achieved (n = 17); intervention arm in whom PDA closure was not achieved (n = 13); placebo arm (n = 30); low risk infants (n = 13). The main outcome measure was CLD/Death.

RESULTS

The rates of CLD/Death were lower in the Intervention Success Group (29%) when compared to the Intervention Failure Group (85%) or the Placebo Group (60%, all p < 0.05). There was no difference in CLD/Death between the Intervention Success and Low Risk Groups (8%, p > 0.05). A persistent PDA beyond Day 8 was associated with CLD/Death (aOR 6.5 [1.7-25.5]).

CONCLUSIONS

Early shunt elimination in preterm infants with a PDA may reduce respiratory morbidity when compared to infants with prolonged shunt exposure.

Oral ibuprofen promoted cholestatic liver disease in very low birth weight infants with patent ductus arteriosus

OBJECTIVES

Hemodynamically significant patent ductus arteriosus (hsPDA) in very low birth weight (VLBW) infants is routinely treated in many countries with oral ibuprofen. This study retrospectively assessed whether the risk of cholestatic liver disease (CLD) increased due to oral ibuprofen administration in VLBW infants.

METHODS

A total of 122 VLBW preterm infants (26∼32 weeks, birth weight<1500g) diagnosed with patent ductus arteriosus (PDA) admitted to our neonatal intensive care unit (NICU) between September 2016 to August 2018 were included. Sixty-four infants were diagnosed with hs-PDA and received ibuprofen treatment. VLBW infants with PDA untreated with ibuprofen served as controls. Soybean oil and fat emulsions were routinely added to parenteral nutrition (PN). Once CLD was diagnosed, the fat emulsions were immediately replaced with multi-oil fat emulsion injections. To assess the independent association of treatment and duration of ibuprofen with CLD and duration of fasting and PN, binary logistic regression or multivariate linear regression analyses were conducted, adjusting for major confounders (birth weight, gestational age, Clinical Risk Index for Babies, and cholestasis-associated risk factors).

RESULTS

The duration of PN increased due to ibuprofen treatment for 6.559 days (95% CI: 1.769, 11.349; P=0.008), and the risk of prolonged fasting (cutoff>5 days) might have increased due to ibuprofen treatment (OR: 3.043, 95% CI: 0.965, 9.594; P=0.057). Furthermore, CLD was influenced by ibuprofen treatment (OR: 6.730; 95% CI: 1.279, 35.41; P=0.024), early thrombocytopenia 7 days postnatal (OR: 6.996; 95% CI: 1.769, 27.658; P=0.004), and late onset sepsis (OR: 6.976; 95% CI: 1.561, 31.169; P=0.011). Further analysis adjusting for cholestasis-associated risk factors revealed that CLD was influenced by the duration of ibuprofen treatment (OR: 2.864; 95% CI: 1.104, 7.422; P=0.030), Platlets counts 7 days postnatal (OR: 0.971; 95% CI: 0.950, 0.994; P=0.013), and duration of antibiotics (OR: 1.134; 95% CI: 1.002, 1.282; P=0.046).

CONCLUSIONS

This retrospective study indicated oral ibuprofen duration-dependently increased the risk of CLD in VLBW infants with PDA, and early thrombocytopenia served as the critical risk factor.

Does high dose intravenous acetaminophen affect liver function for PDA closure in premature neonate?

Objectives

The aim of this study was to collect consistent data on the efficacy and safety and evaluation hepatotoxicity of intravenous acetaminophen for the treatment of PDA in preterm infants.

Methods

This is an observational longitudinal prospective study on 46 preterm infants with PDA who treated with high dose of acetaminophen and evaluated with echocardiography and serum liver enzymes at Hafez and Zeinabiyeh hospitals from January 2016 to December 2019.

Result

Forty-six preterm infants with PDA treated with intravenous acetaminophen. Rate of closure of PDA was 82.6. There was no significant difference after treatment regarding AST, ALT, Albumin, total and direct bilirubin (P value > 0.05) and no adverse side effects were observed in association with intravenous acetaminophen.

Conclusion

High dose of acetaminophen is not more effective than that with standard doses although without hepatotoxic side effect for PDA closure.

Ratio of arterial blood pressures at borders of window surrounding systolic peak indicates patent ductus arteriosus in preterm infants

OBJECTIVE

Presence of a patent ductus arteriosus (PDA) in neonates is assessed by echocardiography. Echocardiographic assessment has disadvantages, primarily its discontinuous nature. We hypothesize that the continuously measured ratio of arterial blood pressures (ABP) at the borders of a window surrounding the systolic peak ratio discriminates non-PDA from PDA patients.

APPROACH

Preterm infants (gestational age <32 weeks) with and without PDA were included. Patients were divided into controls (n = 8) and PDA patients (n = 22), the latter with a subset of patients with closed PDA after three doses Ibuprofen (n = 10). For each patient, a six-hour ABP segment from 12 AM to 6 AM on the day of echocardiographic assessment patency or closure of the DA was selected. The mean ratio of the ABP values a samples before and p samples after the systolic peak (R _ABP) was calculated for each segment. If R _ABP < 1, the patient was predicted to have a PDA. The a and p with the least misclassifications were selected (-64 and +104 ms).

MAIN RESULTS

R _ABP was significantly lower in PDA patients (median 0.95, IQR 0.06) compared to controls (median 1.05, IQR 0.10; p = 0.0024). R _ABP correctly predicted 19 out of 22 patients (86.4%) and six out of eight controls (75%). R _ABP increased after closure in nine out of 10 patients (median 1.01, IQR 0.04; p = 0. 0182).

SIGNIFICANCE

R _ABP may discriminate preterm PDA patients from non-PDA patients and can be calculated continuously from clinical data measured during standard of care.

Comparison of the effect of continuous and standard intermittent bolus paracetamol infusion on patent ductus arteriosus

The aim of this study was to evaluate the effect of paracetamol on patent ductus arteriosus (PDA) closure and clinical outcomes in preterm infants when used as standard intermittent bolus and continuous intravenous (IV) infusion. Preterm neonates with birth weight (BW) ≤ 1500 g and gestational age (GA) ≤ 30 weeks were included in this study. During the study period, IV paracetamol therapy was given to all infants with hemodynamically significant patent ductus arteriosus (hsPDA). The patients were divided into the standard IV intermittent bolus infusion group and the continuous IV infusion group. Standard IV intermittent bolus paracetamol therapy was administered in the form of 15-mg/kg doses as 1-h infusions every 6 h for 5 days, while continuous IV paracetamol infusion therapy was administered as a 60-mg/kg/day dose continuously for 5 days. During the study period, 247 patients were evaluated, of which a total of 137 patients with hsPDA were included. There were no significant differences between the intermittent bolus and continuous infusion groups in terms of mean GA or BW. The continuous paracetamol infusion group had significantly higher rates of PDA-related morbidities, multiple paracetamol courses, and PDA ligation procedure compared with the standard intermittent bolus group.Conclusion: Our results were the first in the literature to compare IV paracetamol infusion regimens for PDA. Our results indicate that standard intermittent bolus infusion is still the most appropriate IV paracetamol regimen for the treatment of PDA.Trial registration: ClinicalTrials.gov Identifier: NCT04469413 What is Known: • Paracetamol has been proposed for the treatment of patent ductus arteriosus in preterm neonates. • There is no consensus on the duration and form of administration of paracetamol in hsPDA, and the information on this issue is insufficient. What is New: • Our study was the first in the literature to compare IV paracetamol infusion regimens for PDA. • Standard intravenous intermittent bolus paracetamol infusion was more effective in pharmacologic PDA closure compared with continuous intravenous paracetamol infusion and was associated with lower rates of PDA-related BPD, NEC, and need for ligation.

A Pilot Randomized Controlled Trial of Early Targeted Patent Ductus Arteriosus Treatment Using a Risk Based Severity Score (The PDA RCT)

OBJECTIVES

To evaluate the feasibility of recruiting preterm infants to a randomized controlled trial of patent ductus arteriosus (PDA) treatment based on a PDA severity score (PDAsc) and to characterize challenges in obtaining consent, compliance with the protocol, and PDA closure rates.

STUDY DESIGN

This single-center, randomized control pilot study of 60 infants <29 weeks of gestation with a high PDAsc (≥5.0) at 36-48 hours of age receiving either ibuprofen or placebo intravenously. The study protocol did not allow for additional PDA therapy within the first 2 weeks. We reported the rate of consent, open label treatment, and PDA closure rates. The primary outcome was chronic lung disease or death.

RESULTS

We approached 83 families for enrollment with 73 (88%) providing consent; 13 infants had a PDAsc of <5; of the remaining infants, 30 were assigned ibuprofen and 30 received placebo. Eight infants received open label treatment in the first 2 weeks (12%). The overall PDA closure rate after treatment was 57% in the intervention group and 17% in the control group (P < .01). There was no difference in the primary clinical outcome (OR, 0.8; 95% CI, 0.3-2.1).

CONCLUSIONS

Using a PDAsc for infant recruitment to a PDA treatment randomized controlled trial is feasible. There is a high rate of consent and relatively low rate of open-label PDA treatment. The overall PDA closure rate in the intervention arm was low placing the emphasis on devising more effective PDA closure strategies in future randomized controlled trials.

TRIAL REGISTRATION

ISRCTN (13281214) and European Union Drug Regulating Authorities Clinical Trials Database (2015-004526-33).

Patent Ductus Arteriosus Clinical Trials: Lessons Learned and Future Directions

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

Predictors of successful patent ductus arteriosus closure with acetaminophen in preterm infants

OBJECTIVE

Evaluate predictors of successful PDA closure following acetaminophen treatment.

STUDY DESIGN

Retrospective cohort study of ≤30 weeks GA infants born from 1 January 2013-30 September 2019, and treated with single course acetaminophen by symptomatic PDA treatment strategy. Multiple maternal and neonatal variables were identified as potential predictors. Univariate analysis and multivariable regression models were applied to evaluate the strongest predictors.

RESULTS

Sixty-six patients were included, 28 (42.4%) had successful PDA closure following acetaminophen. Success was associated with GA > 26 weeks (65% vs. 33%, AUC = 0.64), birthweight >750 g (53% vs. 32%, AUC = 0.61), PDA size ≤0.2 cm (63% vs. 32%, AUC = 0.64), and no prior indomethacin use (56% vs. 33%, AUC = 0.61). Multivariable model identified GA > 26 weeks (RR = 1.92, CI 1.20-3.09) and PDA size ≤0.2 cm (RR: 1.82, CI 1.11-2.98) as the strongest predictors.

CONCLUSION

Acetaminophen may be more successful in targeted PDA closure in >26 weeks GA infants with PDA size ≤0.2 cm.

Left Vocal Cord Paralysis, Lung Function and Exercise Capacity in Young Adults Born Extremely Preterm With a History of Neonatal Patent Ductus Arteriosus Surgery-A National Cohort Study

Background: Left vocal cord paralysis (LVCP) is a known complication of patent ductus arteriosus (PDA) surgery in extremely preterm (EP) born neonates; however, consequences of LVCP beyond the first year of life are insufficiently described. Both voice problems and breathing difficulties during physical activity could be expected with an impaired laryngeal inlet. More knowledge may improve the follow-up of EP-born subjects who underwent PDA surgery and prevent confusion between LVCP and other diagnoses. Objectives: Examine the prevalence of LVCP in a nationwide cohort of adults born EP with a history of PDA surgery, and compare symptoms, lung function, and exercise capacity between groups with and without LVCP, and vs. controls born EP and at term. Methods: Adults born EP (<28 weeks' gestation or birth weight <1,000 g) in Norway during 1999-2000 who underwent neonatal PDA surgery and controls born EP and at term were invited to complete questionnaires mapping voice-and respiratory symptoms, and to perform spirometry and maximal treadmill exercise testing. In the PDA-surgery group, exercise tests were performed with a laryngoscope positioned to evaluate laryngeal function. Results: Thirty out of 48 (63%) eligible PDA-surgery subjects were examined at mean (standard deviation) age 19.4 (0.8) years, sixteen (53%) had LVCP. LVCP was associated with self-reported voice symptoms and laryngeal obstruction during exercise, not with lung function or peak oxygen consumption (VO₂peak). In the PDA-surgery group, forced expiratory volume in 1 second z-score (z-FEV₁) was reduced compared to EP-born controls (n = 30) and term-born controls (n = 36); mean (95% confidence interval) z-FEV₁ was -1.8 (-2.3, -1.2), -0.7 (-1.1, -0.3) and -0.3 (-0.5, -0.0), respectively. For VO₂peak, corresponding figures were 37.5 (34.9, 40.2), 38.1 (35.1, 41.1), and 43.6 (41.0, 46.5) ml/kg/min, respectively. Conclusions: LVCP was common in EP-born young adults who had undergone neonatal PDA surgery. Within the PDA-surgery group, LVCP was associated with self-reported voice symptoms and laryngeal obstruction during exercise, however we did not find an association with lung function or exercise capacity. Overall, the PDA-surgery group had reduced lung function compared to EP-born and term-born controls, whereas exercise capacity was similarly reduced for both the PDA-surgery and EP-born control groups when compared to term-born controls.

A Randomized Placebo-Controlled Pilot Trial of Early Targeted Nonsteroidal Anti-Inflammatory Drugs in Preterm Infants with a Patent Ductus Arteriosus

OBJECTIVE

To establish the feasibility of a future large randomized trial to compare early treatment with nonsteroidal anti-inflammatory drugs (NSAIDs) while awaiting spontaneous patent ductus arteriosus (PDA) closure.

STUDY DESIGN

Preterm infants at <29 weeks of gestation with a PDA diameter >1.5 mm and <72 hours after birth were randomized to NSAIDs vs placebo. No open-label NSAID treatment was allowed in either arm, but all infants with PDA volume load received supportive management, including optimization of airway pressure, careful fluid management, and diuretics as needed. The pilot outcomes were recruitment rate and incidence of open-label treatment. Secondary clinical outcomes included chronic lung disease or death, the planned primary outcome for a future large trial.

RESULTS

Overall, 54% of the approached parents consented to participate in the study. The median recruitment rate was 3 infants per month, and a total of 72 infants were randomized. One patient in each arm received open-label treatment. PDA closure rates were 74% for the NSAIDs arm vs 30% for the placebo arm, but this was not associated with significant changes in clinical outcomes.

CONCLUSIONS

This pilot trial showed that recruitment of more than one-half of eligible infants with a low incidence of open-label treatment is feasible. PDA closure rates and clinical outcomes were similar to those reported in previous PDA trials.

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.

N-terminal pro-brain natriuretic peptide used for screening hemodynamically significant patent ductus arteriosus in very low birth weight infants: How and when?

BACKGROUND

N-terminal pro-B-type natriuretic peptide (NTproBNP) appears to be a useful tool for diagnosing hemodynamically significant patent ductus arteriosus (hsPDA) in preterm infants. However, a consensus for its application has not been reached.

OBJECTIVE

The present study aims to evaluate the role of NTproBNP in predicting hsPDA in preterm infants, and explore the optimal cutoff value and testing-time.

METHODS

A prospective blind study of 120 preterm infants with birth weights of < 1,500 g was conducted at the NICU of Peking University Shenzhen Hospital. Blood samples were successively collected on the first three days after birth for NTproBNP analysis. Echocardiographies were performed on day three of life to confirm the status of the ductus arteriosus. A receiver operating characteristic curve (ROC) analysis was performed to determine the ability of NTproBNP to recognize hsPDA.

RESULTS

NTproBNP was significantly higher in infants with hsPDA, than in infants in the control group, on both day two (P < 0.001) and day three (P < 0.001). On day two, a NTproBNP cutoff value of 3,689.0 pmol/L offered an optimal predictive value for hsPDA, while on day three, the optimal cut-off value for hsPDA was 2,331.5 pmol/L. The investigators proposes day three of life (48-72 hours) as the optimal testing time.

CONCLUSION

The NTproBNP biomarker during the early neonatal period can be a useful tool for screening and assessing hsPDA in premature infants, especially on day three of life.

Do Calcium and Potassium Levels Influence Ductal Patency in Preterm Infants?

OBJECTIVE

We investigated the relationship of serum potassium (K⁺) and ionized calcium (iCa²⁺) levels with the persistence of ductus arteriosus.

STUDY DESIGN

This retrospective cohort study included infants with birth weight < 1,500 g and gestational age < 32 weeks. Serum K⁺ and iCa²⁺ levels at the 1st and 48th hour of life were measured from samples. The difference between the two levels was calculated for both serum K⁺ (ΔK⁺) and iCa²⁺ (ΔCa²⁺). These values were compared between hemodynamically significant patent ductus arteriosus (hsPDA) and non-hsPDA.

RESULTS

Of 1,322 hospitalized preterm nonates, 1,196 were included in the study. Mean serum K⁺ levels at the 1st and 48th hour were higher and iCa²⁺ levels at the 1st and 48th hour were lower in hsPDA and non-hsPDA, respectively (p < 0.001). Ionized ΔCa²⁺ (-0.06 ± 0.13 vs. -0.02 ± 0.12 mmol/L) was higher in hsPDA (p < 0.001).

CONCLUSION

We demonstrated that serum K⁺ and iCa²⁺ level might play a role in ductal constriction.

Drug exposure for PDA closure in France: a prospective, cohort-based, analysis

PURPOSE

To describe the exposure to drugs used for the treatment of patent ductus arteriosus (PDA) in a large cohort of preterm infants born before 32 weeks of gestation.

METHODS

A prospective observational cohort analysis was conducted during 2 years in 28 French level 3 NICU using the same computerized order-entry system. The main outcome was "a medically treated PDA," defined as exposure to ibuprofen, indomethacin, or paracetamol prescribed with the indication of PDA closure. Secondary outcomes were as follows: time of the first treatment administration; total exposure to furosemide during hospitalization; and rate of PDA refractory to pharmacological closure.

RESULTS

The study cohort consisted of 2614 infants. Among them, 474 (18.1%) received a medical treatment for PDA, with a mean postnatal age at treatment of 4.3 ± 6.6 days. The drug used as a first-line treatment was ibuprofen in 89.5% and paracetamol in 10.5%. One hundred and ninety-five infants (7.4%) had a PDA refractory to pharmacological closure. At the multivariate analysis, factors associated with PDA refractory to pharmacological closure (OR; 95% CI) were as follows: gestational age (GA) (0.81; 0.72-0.90), paracetamol as the first-line treatment (0.32; 0.15-0.68), and pharmacological treatment before 48 h of life (0.63; 0.43-0.94). 24.6% of the study cohort was exposed to furosemide (cumulative dose 6.5 ± 12.6 mg/kg). Variables significantly associated with higher cumulative doses of furosemide were lower GA and ibuprofen treatment (both p < 0.0001).

CONCLUSION

Drug utilization patterns in infants with PDA vary among centers. Pharmacoepidemiology studies can provide new information on factors associated with PDA refractory to medical treatment.

Ligation of patent ductus arteriosus in very low birth weight premature infants

BACKGROUND

Patent ductus arteriosus (PDA) is frequently encountered in premature infants. Optimal management of PDA remains undefined. We aim to assess the national trend for PDA ligation over 18 years and evaluate mortality and associated morbidities.

METHODS

We used data from the National Inpatient Sample (NIS) and KID of the Healthcare Cost and Utilization Project (HCUP) from 1998 to 2015. All infants with gestational age 24-32 weeks and birth weight <1500 g were included. Patients with PDA were classified into two groups: those who did and did not receive surgical ligation. Associated mortality and morbidities were compared.

RESULTS

A total of 429,900 neonatal admissions were identified. Of them, 149,473 (34.8%) infants had PDA. PDA-ligated infants were 27,364 (6.4%). PDA ligation was more likely in those with smaller gestational age and with birth weight <1000 g. A steady decline in PDA ligation was noticed since 2004. The mortality rate in PDA-ligated infants was less than in PDA-non-ligated infants (7.5% vs. 8.9%; OR = 0.82; 95% CI: 0.78-0.86; p < 0.001). However, the prevalence rates of pulmonary hemorrhage and necrotizing enterocolitis (NEC) were greater in PDA-ligated infants (OR = 1.58; 95% CI: 1.49-1.67; p < 0.001, and OR = 1.32; 95% CI: 1.26-1.38; p < 0.001, respectively).

CONCLUSIONS

Ligation of PDA has been steadily declining since 2004. Despite higher morbidities, PDA-ligated infants had less mortality.

Use of combination therapy with acetaminophen and ibuprofen for closure of the patent ductus arteriosus in preterm neonates

Objective

To compare effectiveness and safety of combination therapy (acetaminophen and ibuprofen) to monotherapy (ibuprofen, indomethacin, or acetaminophen alone) in treatment of the patent ductus arteriosus (PDA) in premature neonates.

Methods

This was a retrospective cohort study of neonates admitted to a tertiary-level neonatal intensive care unit. Included neonates were born at <32 weeks gestation and received pharmacotherapy for PDA closure. Based on the primary therapy received, our cohort was divided into the following four groups: indomethacin alone, ibuprofen alone, acetaminophen alone, and ibuprofen and acetaminophen (in combination). Baseline characteristics, effectiveness, safety, neonatal mortality, and morbidities rates between these groups were compared.

Results

One hundred and forty neonates were analyzed; 17 received combination therapy, and 123 neonates received monotherapy: 22 (17.9%) ibuprofen, 29 (23.6%) acetaminophen, and 72 (58.5%) indomethacin. The PDA closure rates were 41.7% for indomethacin, 41.2% for combination therapy, 37.9% for acetaminophen, and 31.8% for ibuprofen (P=0.100). Rates of adverse effects were comparable between the groups.

Conclusion

The rate of ductal closure was not different between combination therapy and monotherapy. The study did not demonstrate any increased adverse effects in the combination group. Future well-designed prospective clinical trials are needed to guide clinical practice.

Improved ventilation in premature babies after transcatheter versus surgical closure of patent ductus arteriosus

AIMS

Patent ductus arteriosus (PDA) is common in preterm infants and can contribute to morbidity and mortality. We aimed to compare results and outcome of transcatheter closure using the Amplatzer Piccolo Occluder versus surgical closure in 2 matched groups of preterm infants weighing <3000 g.

METHODS AND RESULTS

A total of 147 babies from three tertiary centres were retrospectively analysed. Sixty-four babies undergoing catheter closure were compared with 83 matched surgical cases. Patent ductus arteriosus closure was successful in all cases. During neonatal unit course, mortality was 6.3% (n = 4) after catheterization and 12% (n = 10) after surgery (p = 0.24). Median duration of mechanical ventilation was shorter after catheterisation than after surgery (3 vs 5 days, p = 0.035). Before 4 weeks of age the difference between transcatheter and surgical closure for mechanical ventilation was even more pronounced (3 vs 9 days, p = 0.022). Additionally, when catheterisation was performed before 4 weeks, babies were discharged home earlier as compared to those who underwent closure later in life (39⁺¹ vs. 42⁺¹ weeks, p = 0.021). Such difference was not found in the surgical group.

CONCLUSIONS

Transcatheter closure of patent ductus arteriosus is safe, effective and is associated with shorter mechanical ventilation than after surgery. Hospital stay might be shorter when performed earlier in life.

Defining "Haemodynamic Significance" of the Patent Ductus Arteriosus: Do We Have All the Answers?

Optimum management of the patent ductus arteriosus (PDA) in preterm infants remains one of the most debated topics within the field of neonatology. Despite numerous observational studies and over 60 randomized control trials, consensus on PDA management remains elusive. In order to make meaningful progress on the controversial issue of PDA management, several key factors must be thoroughly addressed; namely (1) accurate identification of infants at greatest risk of long-term morbidities from PDA exposure, (2) acceptance that the PDA is not a dichotomous entity and an individualised approach to its management is required for each neonate, (3) international consensus on what constitutes a haemodynamically significant PDA and (4) the incorporation of multi-organ assessment when evaluating the impact a PDA may pose on overall neonatal physiology. This review assesses the evidence base available supporting various therapeutic strategies for PDA, the deficits in our current knowledge on the definition of haemodynamic significance and future directions to pursue in order to more successfully address this contentious subject.

Prediction of ductus closure and development of adverse clinical outcome by functional echocardiography in very low birth weight newborn

OBJECTIVE

To evaluate the role of functional echocardiography for prediction of patent ductus arteriosus (PDA) closure and development of adverse outcome in very low birth weight newborn.

METHODS AND STUDY DESIGN

Functional echocardiography was done in 143 neonates with birth weight less than 1250 g on day 3. Nine echocardiographic parameters were analyzed for babies with PDA for prediction of spontaneous closure and development of one or more adverse outcomes (bronchopulmonary dysplasia, necrotizing enterocolitis≥stage 2 and intraventricular hemorrhage > grade 2) during hospital stay.

RESULT

The mean (±SD) birthweight and gestational age of the cohort were 1017 (±17) g and 30.8 (±2.7) weeks. PDA was found in 60 (41.9%) babies on day 3 among the recruited babies. Binary logistic regression model showed strong prediction ability of early (day 3) functional echocardiography markers in predicting future spontaneous closure of PDA and development of one or more adverse clinical outcome. In multivariate analysis, abnormal flow pattern (growing or pulsatile) was found to have increased risk for persistence of PDA (adjusted OR 22.9, CI 1.97-269) in comparison to PDA with closing/bidirectional pattern.

CONCLUSION

Early functional echocardiography, especially the flow pattern, is useful for prediction of PDA closure. Adverse clinical outcome prediction is possible with functional echocardiography markers when combined with gestational age and PDA closure status.

Exploration of potential biochemical markers for persistence of patent ductus arteriosus in preterm infants at 22-27 weeks' gestation

BACKGROUND

Early identification of infants at risk for complications from patent ductus arteriosus (PDA) may improve treatment outcomes. The aim of this study was to identify biochemical markers associated with persistence of PDA, and with failure of pharmacological treatment for PDA, in extremely preterm infants.

METHODS

Infants born at 22-27 weeks' gestation were included in this prospective study. Blood samples were collected on the second day of life. Fourteen biochemical markers associated with factors that may affect PDA closure were analyzed and related to persistent PDA and to the response of pharmacological treatment with ibuprofen.

RESULTS

High levels of B-type natriuretic peptide, interleukin-6, -8, -10, and -12, growth differentiation factor 15 and monocyte chemotactic protein 1 were associated with persistent PDA, as were low levels of platelet-derived growth factor. High levels of erythropoietin were associated with both persistent PDA and failure to close PDA within 24 h of the last dose of ibuprofen.

CONCLUSIONS

High levels of inflammatory markers were associated with the persistence of PDA. High levels of erythropoietin were associated with both the persistence of PDA and failure to respond to pharmacological treatment.

Understanding the Pathophysiology, Implications, and Treatment Options of Patent Ductus Arteriosus in the Neonatal Population

BACKGROUND

Patent ductus arteriosus (PDA) is the persistence of a fetal shunt between the pulmonary artery and the aorta. This structure normally closes in the first 3 days after birth; however, closure is delayed in up to 80% of infants born at 25 to 28 weeks of gestation. Persistent PDA results in pulmonary overcirculation and systemic hypoperfusion.

PURPOSE

The purpose of this article is to review pathophysiology and treatment options for PDA.

METHODS

A literature review was conducted using PubMed, CINAHL, and Google Scholar (2013-2018). Search terms included neonate, PDA, pathophysiology, pharmacotherapy, nursing, ligation, indomethacin, ibuprofen, and acetaminophen (paracetamol).

RESULTS

Optimal treatment remains contentious. Options include conservative/medical, pharmacologic, and surgical management. Conservative/medical management includes mild fluid restriction, increased airway pressures, and supportive care. Pharmacologic treatment is accomplished using indomethacin, ibuprofen, or acetaminophen. Surgical intervention is by direct closure or by percutaneous ligation. Treatment may be prophylactic, presymptomatic, or symptomatic. Long-term morbidities associated with PDA include chronic lung disease, retinopathy of prematurity, and neurodevelopmental delay.

IMPLICATIONS FOR RESEARCH

Absence of a universal scoring system for severity of PDA limits accuracy of comparisons among research studies. Lack of a consistent definition also makes it difficult to aggregate data for meta-analyses. Adoption of a consistent scoring system for hemodynamic significance would facilitate comparisons of outcomes among research studies.

IMPLICATIONS FOR PRACTICE

Clinicians should be aware of treatment options for PDA and their implications on neonatal outcomes. For nurses, anticipation of possible side effects is important for performance of focused assessments.

Neuroprotective Care of Extremely Preterm Infants in the First 72 Hours After Birth

Birth at extremely low gestational ages presents a significant threat to infants' survival, health, development, and future well-being. After birth, a critical period of brain development must continue outside the womb. Neuro-supportive and neuroprotective family centered developmental care for and standardized care practices for extremely preterm infants have been shown to improve outcomes. Neuroprotective interventions must include a focus on the emotional connections of infants and their families. Being in skin-to-skin contact with the mother is the developmentally expected environment for all mammals and is especially important for supporting physiologic stability and neurodevelopment of preterm infants.

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

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

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

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

Photoplethysmographic assessment of pulse transit time correlates with echocardiographic measurement of stroke volume in preterm infants with patent ductus arteriosus

OBJECTIVE

We aimed to correlate photoplethysmographic parameters with stroke volume in infants with PDA. Photoplethysmography constitutes the optical signal in pulse oximetry.

STUDY DESIGN

Stroke volume was determined echocardiographically. Pulse transit time, right hand to foot arrival time difference, and relative amplitude were measured from pulse oximeter and ECG waveforms. Photoplethysmographic parameters before and after PDA closure were compared with stroke volume.

RESULTS

After PDA closure, pulse transit time to the hand and to the foot were prolonged (54.7 ± 6.7 vs 65.5 ± 9.8 ms, p < 0.001, 82.5 ± 12.8 vs 88.6 ± 10.6 ms, p = 0.03), arrival time difference decreased (27.7 ± 7.6 vs 23.1 ± 5.6 ms, p = 0.021), and relative amplitude decreased (from 2.1 ± 0.7% to 1.5 ± 0.5%, p = 0.003). The time-based photoplethysmographic parameters correlated with stroke volume.

CONCLUSIONS

Photoplethysmographic waveform parameters are significantly different before and after PDA closure and the time-based parameters correlate well with stroke volume. Monitoring pulse transit time may assist in evaluation for spontaneous PDA closure or response to therapy.