Spontaneous Closure of the Ductus Arteriosus in Preterm Infants: A Systematic Review

Cumulative radiation dose in children with congenital heart disease: national data 2000-2021, stratified by diagnosis, age, and imaging modality

BackgroundPediatric congenital heart disease (CHD) patients often undergo procedures involving ionizing radiation for diagnosis, treatment, and follow-up. Their cumulative radiation burden may increase their risk of late effects.PurposeTo assess radiation exposures from cardiac catheterization and thoracic imaging in pediatric CHD patients, stratified by diagnosis, age, and imaging modality.Material and MethodsRadiation exposure (cardiac catheterization, thoracic computed tomography [CT] and radiography) was retrospectively collected for individuals aged <18 years (born 2000-2020) with at least one catheterization for CHD. Cumulative effective dose (CED) was estimated per patient by diagnosis. Age-based variation in examination frequency and exposure was examined.ResultsA total of 1574 patients underwent 23,558 radiographic examinations. The most common diagnoses, atrial septal defect (ASD; 31% of the cohort) and patent ductus arteriosus (PDA; 30%), had a median CED of 2.3 and 2.9 mSv, respectively. The diagnoses resulting in highest CEDs were hypoplastic left heart syndrome (HLHS; 2.6%, 37.5 mSv), double inlet left ventricle (DILV; 2.4%, 48.4 mSv), and double outlet right ventricle (DORV; 2.6%, 31.3 mSv). Cardiac catheterization, thoracic CT, and radiography contributed 94%, 4%, and 2% of CED, respectively. Effective doses per patient for each diagnosis varied with age. Doses from cardiac catheterizations tended to be higher for patients exposed at ≤30 versus 31-90 months old.ConclusionMost patients with ASD and PDA had low CED and patients with HLHS, DILV, and DORV received ≥30 mSv. Patients with severe CHD often required early catheterization, which, in turn, led to higher effective doses in these patients due to larger conversion coefficients between dose area product/dose length product and effective dose in individuals aged ≤30 months.

High-Humidity Care May Prevent the Development of Patent Ductus Arteriosus in Premature Infants

BACKGROUND

Recently, the role of a rapid increase in serum osmolality in the inhibition of postnatal ductal closure has garnered attention. This study evaluated the efficacy of high-humidity care in preventing the onset of patent ductus arteriosus (PDA) in extremely premature infants.

METHODS AND RESULTS

The high-humidity group (HHG) comprised 28 infants (240to 276weeks gestational age) recruited prospectively within 6 h after birth between July 2019 and September 2021; these infants were cared for in 90% humidity for the first 72 h of life. The incidence of PDA within the first 7 days of life and the rate of increase in serum sodium concentrations were compared between the HHG and a conventionally managed historical control group (CG; 29 infants born in 2016-2017). Twelve (43%) infants in the HHG and 22 (76%) in the CG developed PDA (P=0.016). Multivariate logistic regression analysis revealed that high-humidity care was effective in reducing the incidence of PDA onset (odds ratio 0.265; 95% confidence interval 0.078-0.907). The rate of increase in serum sodium concentrations was significantly lower in the HHG than CG (median 0.29 [interquartile range 0.21-0.39] vs. 0.46 [interquartile range 0.32-0.62] mEq/L/h, respectively; P<0.001).

CONCLUSIONS

High-humidity care for the first 72 h of life may help reduce the onset of PDA in extremely preterm infants by avoiding rapid increases in serum sodium concentrations.

Comparison of the Effectiveness of Paracetamol and Ibuprofen in the Management of Patent Ductus Arteriosus in Preterm Neonates: A Randomized Controlled Trial

BACKGROUND

Patent ductus arteriosus is one of the most common cardiac conditions affecting the neonates. Considering the lack of studies done on this topic in healthcare settings in Khyber Pakhtunkhwa province, this study aims to find out the comparative effectiveness of paracetamol and ibuprofen in management of PDA in our healthcare setting to conclude a better management option for the condition.

OBJECTIVE

To find and compare the effectiveness of paracetamol and ibuprofen in the closure of patent ductus arteriosus in preterm neonates.

METHODOLOGY

This randomized controlled trial was conducted in the Department of Nursery and Neonatal Intensive Care Unit, Khyber Teaching Hospital, Peshawar, Pakistan, from 10th April 2024 to 10th October 2024. A total of 256 neonates of both genders with patent ductus arteriosus were included. Group A received oral paracetamol, and Group B received oral ibuprofen. The effectiveness of the treatments was evaluated at the end of the treatment period.

RESULTS

The age range in this study was from 48 to 96 h, with a mean age of 71.79 ± 13.10 h in Group A and 73.40 ± 11.81 h in Group B. Efficacy was observed in 107 (83.6%) patients in Group A compared to 90 (70.3%) patients in Group B, showing a statistically significant difference (P = 0.011).

CONCLUSION

Our study has concluded that paracetamol is more effective than ibuprofen in closing patent ductus arteriosus. The trials were retrospectively registered at NIH Trial Registry (NCT06601114) https://clinicaltrials.gov/study/NCT06601114 dated 15/09/2024.

Blood pressure increase preceded spontaneous and paracetamol-induced, early ductal closure in very preterm infants

AIM

To investigate the blood pressure (BP) and ductal calibre patterns associated with early ductal closure in very low gestational age (<32 weeks) infants.

METHODS

Blood pressure was continuously measured intra-arterially among 43 infants participating in a randomised, double-blind trial of 4 days prophylactic intravenous paracetamol. Early closure of the ductus was verified by daily ultrasound examinations. The BP recordings, before and after the verified ductal closure, were examined and compared to control infants without ductal closure. In the 24-h preceding the ultrasound-verified ductal closure, periods of increased BP were searched and identified as suggestive ductal closure time points. In control infants without ductal closure, BP trends were examined during the corresponding age.

RESULTS

Mean arterial BP increased significantly before ductal closure (p < 0.001) and stayed higher than in the control group. Mean BP during the 8 h preceding closure significantly predicted the ductal closure [OR 2.094 (95% CI 1.209-3.630), p = 0.008], and multiple potential confounders failed to abolish this association. A linear decrease pattern in ductal calibre was significantly associated with the ductal closure.

CONCLUSION

Blood pressure increased and stabilised before the early ductal closure, offering potential implications on treatment strategies of very premature infants.

Oral ibuprofen versus placebo in closure of patent ductus arteriosus in preterm neonates, a randomized control trial

BACKGROUND

A consensus on treatment of patent ductus arteriosus (PDA) in preterm neonates remains elusive. Conservative management has recently gained popularity due to medical treatment lacking the evidence of benefit in terms of mortality and morbidity.

OBJECTIVE

This study compares the efficacy of the standard dose of oral Ibuprofen versus placebo in the closure of PDA in preterm neonates ≤34 weeks gestation.

METHODS

Eighty enrolled preterm neonates with a hemodynamically significant PDA (hsPDA) were randomized to either receive an early 3-day course oral ibuprofen or placebo (1:1). The open-label option and an extended oral ibuprofen therapy were offered if there were concerns over patient's clinical condition being attributed to PDA and only if showing evidence of systemic and/or pulmonary hyperperfusion.

RESULTS

No significant difference in PDA closure between both groups (62.5% vs 65% in Ibuprofen & placebo group respectively, p = .816). No significant difference was observed between groups in mortality (p = 1), Bronchopulmonary dysplasia (BPD) (p = 1), or necrotizing enterocolitis (NEC) (0.5). Placebo group required a longer duration of inotropic support (median of 10 vs 7.5 days in Ibuprofen group, p = .013) and were prescribed more diuretic therapy (27 vs 18 in Ibuprofen group, p = .043).

CONCLUSION

The standard dose of oral ibuprofen was comparable to placebo in early treatment of hsPDA in preterm neonates less than 34 weeks in terms of effect on ductal closure after one course of treatment, incidence of mortality, and morbidities like NEC, and BPD. Failure of ductal closure itself was associated in both groups with increased mortality, failure to reach full feeds, and more use of vasopressors and inotropes.

A comparison of different dosing regimen of intravenous paracetamol for hemodynamically significant patent ductus arteriosus closure in premature neonates <32 weeks: a prospective observational study

OBJECTIVE

To compare the efficacy of low vs conventional dose intravenous paracetamol in early closure of haemodynamically significant patent ductus arteriosus within 7 days of life.

METHODS

Preterm infants (<32 weeks of gestation) having echocardiographic evidence of hsPDA were given low dose (15 mg/kg initially followed by 7.5 mg/kg every 6 hourly) vs conventional dose (15 mg/kg every 6 hourly) for 5-7 days.

RESULTS

In total, 56 infants (28 in each group) were enrolled. Ductal closure was achieved in 96% infants in the low-dose group and 100% infants in the conventional group (P = 1.00). Secondary outcomes, including ductal reopening and need for the second course of medical treatment (21% vs 3.5%, P = 0.1), median duration of hospital stay [30 (15, 43.5) vs 27 (18.5,45), P = 0.64], cumulative oxygen requirement [17.5 (7, 25) vs 14 (8.5, 25), P = 0.89], mortality (10.7% vs 25%, P = 0.29) and other morbidities, were comparable in both the groups. Median paracetamol levels were comparable in both the groups [53.4 μg/L (47, 2,70) vs 62.5 (55.6, 81.2), P = 0.67].

CONCLUSION

Low-dose paracetamol was non-inferior to conventional dose paracetamol for early ductal closure in preterm infants.

Increasing the dose of ibuprofen with postnatal age to close a hemodynamically significant patent ductus arteriosus in very preterm infants

Patent ductus arteriosus (PDA) is associated with neonatal morbidities in high-risk preterm infants. Early neonatal treatment by ibuprofen induces the ductus arteriosus (DA) closure in approximatively 60% of infants. Dose escalation of ibuprofen according to postnatal age has been suggested for improving the DA closure rate. The aim of this study was to assess the efficacy and tolerance of an increasing dose regimen of ibuprofen. This single-center retrospective cohort study involved infants hospitalized from 2014 to 2019 in our neonatal unit. Selection criteria were gestational age < 30 weeks, birth weight < 1000 g, and treatment by ibuprofen. Three dose levels were used and consisted of a daily intravenous injection of ibuprofen-tris-hydroxymethyl-aminomethane (ibuprofen-THAM) for three consecutive days: (i) 10 -5 -5 mg/kg before the 70th h of life (H70) (dose level 1), (ii) 14 -7 -7 mg/kg between H70 and H108 (dose level 2), (iii) 18 -9 -9 mg/kg after H108 (dose level 3). The ibuprofen-induced DA closure was compared between ibuprofen schedules, and the Cox proportional-hazard regression was performed to identify factors associated with the ibuprofen efficacy. Tolerance was assessed through renal function, acidosis, and platelet count. One hundred forty-three infants met the inclusion criteria. The ibuprofen-induced DA closure was observed in 67 infants (46.8%). One course of ibuprofen at dose level 1 was more efficient in closing the DA than other schedules (dose level 1, one course (n = 70): 71%, dose level 2 or 3, one course (n = 20): 45%, two-course schedules (n = 53): 15%, p < 0.0001). Independent factors associated with ibuprofen-induced DA closure were a complete antenatal schedule of steroids (p = 0.001), a lower CRIB II score (p = 0.009), and a lower and earlier exposure to ibuprofen (p < 0.0001 and p = 0.002). No severe side effects were observed. Neonatal mortality and morbidities were similar regardless of the infant's response to ibuprofen.  Conclusion: Increasing ibuprofen doses with postnatal age failed to reach an efficacy similar to earlier treatment. Although the infant response to ibuprofen was likely to depend on multiple factors, the optimal use of ibuprofen included its early initiation. What is Known: • Ibuprofen is the current first-line treatment for patent ductus arteriosus during the early neonatal period in very preterm infants. • However, the ibuprofen efficacy rapidly declined with postnatal age during the first week of life. A dose escalation of ibuprofen according to postnatal age has been suggested to improve the ibuprofen-induced ductus arteriosus closure. What is New: • The rapid drop of ibuprofen's ability to close hemodynamically significant patent ductus arteriosus persisted beyond the postnatal day 2 despite the dose adjustment arguing for an early initiation to optimize its efficacy. • The early selection of patients who will suffer from patent ductus arteriosus-related morbidities and who will positively respond to ibuprofen is an issue that could determine the future place of ibuprofen in the patent ductus arteriosus management.

The Effect of Oral Acetaminophen on Open Arterial Duct Closure in Premature Infants Less Than 32 Weeks

Background

In most term neonates, the ductus arteriosus closes functionally on the first day of life, and a permanently open ductus arteriosus is abnormal.

Objectives

To evaluate the effect of oral acetaminophen on patent arterial duct (PDA) closure in premature infants less than 32 weeks.

Methods

This randomized clinical trial was performed on 140 preterm neonates with gestational age less than 32 weeks and birth weight less than 1,500 g, admitted to the neonatal intensive care unit of Ali Enbe Abitalib Hospital in Zahedan between 2019 and 2021. The neonates were randomly divided into two groups, with and without acetaminophen administration. In the intervention group, acetaminophen drops were started during the first 24 hours after birth and were administered for five days. In both groups, echocardiography was performed five days after birth. Finally, the data were analyzed in SPSS software.

Results

About 140 neonates with gestational age of ≤32 weeks and weight at birth ≤1,500 g were admitted for the study. The neonates were equally divided into two groups and acetaminophen medication assigned for one of the groups. Of the 70 neonates who did not receive acetaminophen administration, 75.7% had PDA closure spontaneously; this pattern was 94.3% in patients who had treatment with acetaminophen. This effect of treatment was significant (X2=9.468, p=0.002).

Conclusion

The study showed significant improvement in PDA in neonates receiving paracetamol. This can have a significant impact on the treatment approach to preterm neonates.

Association between Fluid Balance and Treatment Outcome of Ibuprofen for Patent Ductus Arteriosus in Preterm Infants

Background

Excessive fluid intake is a predictor of the development of patent ductus arteriosus (PDA) in preterm infants. Previous studies have examined the relationship between fluid intake and outcomes following ibuprofen for PDA. However, there is a lack of data to determine whether fluid balance has an effect on ibuprofen treatment for PDA. Therefore, this study sought to determine the relationship between fluid balance and outcomes following treatment with ibuprofen for PDA.

Methods

We conducted a retrospective study of 110 infants admitted to the Children's Hospital of Chongqing Medical University between January 2017 and April 2022, who were treated with ibuprofen for hemodynamically significant PDA (hsPDA). We calculated the average fluid balance before and during the two courses of ibuprofen treatment and whether they were significantly associated with outcomes in hsPDA patients.

Results

In the first course of ibuprofen treatment (FIT), responders had lower fluid balance before FIT compared to non-responders [median 31.82 (18.01, 39.66) vs 34.68 (25.31, 43.56) mL/kg/day; p = 0.049], while the fluid balance during FIT [median 40.61 (33.18, 63.06) vs 42.65 (30.02, 57.96) mL/kg/day; p = 0.703] did not differ between responders and non-responders. Fluid balance before the second course of ibuprofen treatment (SIT) (mean 41.58 ± 14.26 vs 35.74 ± 10.99 mL/kg/day; p = 0.322) and during SIT (mean 39.21 ± 12.65 vs 37.00 ± 21.38 mL/kg/day; p = 0.813) was not found to have a significant association with SIT outcome. Multivariate logistic regression analysis showed fluid balance before FIT was a predictor for FIT success [Odds ratio (OR): 0.967; 95% confidence interval (CI): 0.935-0.999; p = 0.042]. Fluid balance within the first week of life had a greater association with the FIT outcome (OR: 0.967, 95% CI: 0.939-0.996, p = 0.027). Gestational diabetes mellitus and higher Apgar scores decreased the possibility of PDA closure after FIT.

Conclusions

Lower fluid balance before FIT, especially within the first week of life appeared to be a predictor for closure of hsPDA after FIT in preterm infants.

Low dose paracetamol for management of patent ductus arteriosus in very preterm infants: a randomised non-inferiority trial

OBJECTIVE

To compare the efficacy of low dose-short course intravenous paracetamol with a conventional dose regimen for early targeted closure of patent ductus arteriosus (PDA).

DESIGN

Single-centre, double-blinded, active controlled, randomised non-inferiority trial.

SETTING

Level III neonatal intensive care unit in Western India.

PATIENTS

Preterm infants <30 weeks of gestation requiring mechanical ventilation, or continuous positive airway pressure with FiO₂ ≥0.35 and diagnosed with a haemodynamically significant PDA (hsPDA) at 18-24 hours of postnatal age.

INTERVENTIONS

Low dose (10 mg/kg/dose 6 hourly for 72 hours) versus conventional dose (15 mg/kg/dose 6 hourly for 120 hours) intravenous paracetamol treatment.

MAIN OUTCOME MEASURES

Comparison of the rates of ductal closure at completion of sixth postnatal day, using a prespecified non-inferiority margin of 20%.

RESULTS

A total of 102 infants were enrolled. The median gestational age and birth weight of the included infants were 26.4 weeks and 830 g. At completion of the sixth postnatal day, closure of PDA was achieved in 92% of infants in the low dose group as compared with 94% of those in the standard dose group (risk difference: -1.6%, 95% CI: -11.6% to 8.5%, p=0.38). The rates of rescue therapies, adverse effects and other neonatal morbidities were comparable in both groups.

CONCLUSION

In very preterm infants on significant respiratory support, low dose-short course intravenous paracetamol treatment was non-inferior to a conventional dosing regime of paracetamol for closure of hsPDA in the first week of postnatal age. Larger studies with narrow margins of non-inferiority are required to confirm our findings.

TRIAL REGISTRATION NUMBER

CTRI/2017/10/010012.

Unstable SpO2 in preterm infants: The key role of reduced ventilation to perfusion ratio

Introduction: Instability of peripheral oxyhemoglobin saturation (SpO₂) in preterm infants is correlated with late disability and is poorly understood. We hypothesised that a reduced ventilation to perfusion ratio (V_A/Q) is the key predisposing factor for SpO₂ instability. Methods: We first used a mathematical model to compare the effects of reduced V_A/Q or shunt on SaO₂ stability (SaO₂ and SpO₂ are used for model and clinical studies respectively). Stability was inferred from the slope of the SaO₂ vs. inspired oxygen pressure (P _IO₂) curve as it intersects the 21 kPa P _IO₂ line (breathing air). Then, in a tertiary neonatal intensive care unit, paired hourly readings of SpO₂ and P _IO₂ were recorded over a 24 h period in week old extremely preterm infants. We noted SpO₂ variability and used an algorithm to derive V_A/Q and shunt from the paired SpO₂ and P _IO₂ measurements. Results: Our model predicted that when V_A/Q < 0.4, a 1% change in P _IO₂ results in >8% fluctuation in SaO₂ at 21 kPa P _IO₂. In contrast, when a 20% intrapulmonary shunt was included in the model, a 1% change in P _IO₂ results in <1% fluctuation in the SaO₂. Moreover, further reducing the V_A/Q from 0.4 to 0.3 at 21 kPa P _IO₂ resulted in a 24% fall in SaO₂. All 31 preterm infants [mean gestation (±standard deviation) 26.2 (±1) week] had V_A/Q < 0.74 (normal >0.85) but only two infants had increased shunt at 1.1 (±0.5) weeks' postnatal age. Median (IQR) SpO₂ fluctuation was 8 (7)%. The greatest SpO₂ fluctuations were seen in infants with V_A/Q < 0.52 (n = 10): SpO₂ fluctuations ranged from 11%-17% at a constant P _IO₂ when V_A/Q < 0.52. Two infants had reduced V_A/Q and increased shunt (21% and 27%) which resolved into low V_A/Q after 3-6 h. Discussion: Routine monitoring of P _IO₂ and SpO₂ can be used to derive a hitherto elusive measure of V_A/Q. Predisposition to SpO₂ instability results from reduced V_A/Q rather than increased intrapulmonary shunt in preterm infants with cardiorespiratory disease. SpO₂ instability can be prevented by a small increase in P _IO₂.

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

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

Preterm birth and prescriptions for cardiovascular, antiseizure, antibiotics and antiasthmatic medication in children up to 10 years of age: a population-based data linkage cohort study across six European regions

OBJECTIVES

Preterm children are exposed to many medications in neonatal intensive care units, but little is known about the effect of prematurity on medication use throughout infancy and childhood. We examined prescriptions of cardiovascular medication (CVM), antiseizure medication (ASM), antiasthmatic medication and antibiotics issued/dispensed in the first 10 years of life for very and moderately preterm children compared with term.

DESIGN

Population-based data linkage cohort study linking information from birth records to prescription records.

SETTING

Six registries from five countries in the EUROlinkCAT study.

PARTICIPANTS

The study population included 1 722 912 children, of whom 10 820 (0.6%) were very preterm (<32 weeks gestational age (GA)), 92 814 (5.4%) were moderately preterm (32-36 weeks GA), 1 606 643 (93.3%) were born at term (≥37 weeks GA) and 0.7% had missing GA. Children with major or minor congenital anomalies were excluded (including patent ductus arteriosus).

MAIN OUTCOME MEASURES

Relative risk (RR) of receiving a prescription for CVM, ASM, antiasthmatic and antibiotics.

RESULTS

Very preterm children had a higher RR of receiving a prescription for CVM and ASM than preterm children. For all preterm children, the RR of having a CVM prescription was 3.58 (95% CI 2.06 to 6.23); 2.06 (95% CI 1.73 to 2.41) for ASM; 1.13 (95% CI 0.99 to 1.29) for antiasthmatics and 0.96 (95% CI 0.93 to 0.99) for antibiotics in the first year of life. Increased prescription of CVM, ASM and antiasthmatics persisted for all 10 years of follow-up. Although the RR was highest for CVM and ASM, in absolute numbers more children received prescriptions for antibiotics (42.34%, 95% CI 38.81% to 45.91%) and antiasthmatics (28.40%, 95% CI 16.07% to 42.649%) than for CVM (0.18%, 95% CI 0.12% to 0.25%) and ASM (0.16%, 95% CI 0.13% to 0.20%) in the first year of life.

CONCLUSION

Preterm children had a higher risk of being prescribed/dispensed CVM, ASM and antiasthmatics up to age 10. This study highlights a need for further research into morbidity beyond age 10.

The Effect of Ibuprofen Exposure and Patient Characteristics on the Closure of the Patent Ductus Arteriosus in Preterm Infants

Spontaneous closure of the ductus arteriosus depends on gestational age (GA) and might be delayed in preterm infants, resulting in patent ductus arteriosus (PDA). Ibuprofen can be administered to enhance closure, but the exposure‐response relationship between ibuprofen and the closure of PDA remains uncertain. We investigated the influence of patient characteristics and ibuprofen exposure on ductus closure. A cohort of preterm infants with PDA and treated with ibuprofen was analyzed. Ibuprofen exposure was based on a previously developed population pharmacokinetic study that was in part based on the same study population. Logistic regression analyses were performed with ductus closure (yes/no) as outcome, to analyze the contribution of ibuprofen exposure and patient characteristics. In our cohort of 263 preterm infants (median GA 26.1 (range: 23.7–30.0) weeks, birthweight 840 (365–1,470) g) receiving ibuprofen treatment consisting of 3 doses that was initiated at a median postnatal age (PNA_start) of 5 (1–32) days, PDA was closed in 55 (21%) patients. Exposure to ibuprofen strongly decreased with PNA_start. Overall, the probability of ductus closure decreased with PNA_start (odds ratio (OR): 0.7, 95% CI: 0.6–0.8) and Z‐score for birthweight (Z_{Birthweight‐for‐GA}; OR: 0.8, 95% CI: 0.6‐1.0), and increased with GA (OR: 1.5, 95% CI: 1.1–1.9). For patients with PNA_start < 1 week, concentrations of ibuprofen, GA, and Z_{Birthweight‐for‐GA} predicted probability of ductus closure. During a window of opportunity for ductus closure within the first days of life, probability of closure depends on GA, Z_{Birthweight‐for‐GA}, and ibuprofen exposure. Increased, yet unstudied dosages might increase the effectivity of ibuprofen beyond the first week of life.

Efficacy and Costs of Three Pharmacotherapies for Patent Ductus Arteriosus Closure in Premature Infants

BACKGROUND

The hemodynamic impact of persistent patent ductus arteriosus (PDA) is associated with neonatal morbidities and mortality in preterm newborns. While there has been considerable debate about optimal management of PDA and its impact on clinical outcomes, there is widespread variation in practice, such as using different pharmacotherapies to achieve closure of hemodynamically significant PDA during the first week of life in very low birth weight infants.

AIMS

The objective was to estimate the efficacy of acetaminophen, ibuprofen, and indomethacin with regard to ductal closure and to compare the costs of these three commonly used medications to treat PDA in preterm infants.

METHODS

PubMed, Embase, and Cochrane Registry were searched for trials from the years 2010-2020. We identified 17 randomized clinical trials (RCTs) and 14 case series that enrolled preterm infants < 37 weeks gestational age for inclusion. Pooled estimates of closure rates for acetaminophen (n = 630), ibuprofen (n = 694), and indomethacin (n = 312) were analyzed using the weighted proportion ratio using a Mantel‑Haenszel random effects model. The chi-squared test of proportions was used to determine significance between groups. We accessed cost estimates of pharmacotherapy from the Lexi-Comp average wholesale price database and utilized a decision tree model to appraise cost benefits for the outcome measure of successful PDA closure.

RESULTS

The pooled proportional point estimates of closure rates from RCTs for acetaminophen, ibuprofen, and indomethacin were 70.1% (95% confidence interval [CI] 60-80), 63.4% (95% CI 52.8-74.1), and 71.5% (95% CI 62.3-80.7), respectively. There was no significant statistical difference in closure rates when RCTs and uncontrolled case series were combined. Pairwise comparisons showed both acetaminophen and indomethacin were each more effective in closing PDA than ibuprofen (acetaminophen vs indomethacin: p = 0.01; ibuprofen vs indomethacin: p = 0.02; acetaminophen vs indomethacin: p = 0.93). Comparing costs for successful closure of PDA, at the average wholesale price of different medications, suggested that treatment with acetaminophen costs significantly less, with a mean of $1487 (95% CI 1300-1737), compared to ibuprofen, with a mean of $2585 (95% CI 2214-3104), and indomethacin, with a mean of $2661 (95% CI 2358-3052), per course of treatment.

CONCLUSIONS

Our meta-analysis suggests acetaminophen is non-inferior to both indomethacin and ibuprofen, and costs relatively less for successful PDA constriction in premature infants. Further clinical trials are warranted to compare acetaminophen's safety, along with short- and long-term effects, to help resolve the clinical conundrum of the necessity of early treatment in the management of PDA, and the optimal pharmacological course, if indicated.

Early N-Terminal Pro B-Type Natriuretic Peptide (NTproBNP) Plasma Values and Associations with Patent Ductus Arteriosus Closure and Treatment-An Echocardiography Study of Extremely Preterm Infants

The aim was to investigate the association of gestational age (GA), echocardiographic markers and levels of plasma N-terminal pro-B-type natriuretic peptide (NTproBNP) with the closure rate of a haemodynamically significant patent ductus arteriosus (hsPDA). Ninety-eight Swedish extremely preterm infants, mean GA 25.7 weeks (standard deviation 1.3), born in 2012–2014, were assessed with echocardiography and for levels of NTproBNP. Thirty-three (34%) infants had spontaneous ductal closure within three weeks of age. Infants having spontaneous closure at seven days or less had significantly lower NTproBNP levels on day three, median 1810 ng/L (IQR 1760–6000 ng/L) compared with: infants closing spontaneously later, 10,900 ng/L (6120–19,200 ng/L); infants treated either with ibuprofen only, 14,600 ng/L (7740–28,100 ng/L); or surgery, 32,300 ng/L (29,100–35,000 ng/L). Infants receiving PDA surgery later had significantly higher NTproBNP values on day three than other infants. Day three NTproBNP cut-off values of 15,001–18,000 ng/L, predicted later PDA surgery, with an area under the curve in ROC analysis of 0.69 (0.54–0.83). In conclusion, the spontaneous PDA closure rate is relatively high in extremely preterm infants. Early NTproBNP levels can be used with GA in the management decisions of hsPDA.

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

BACKGROUND

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

METHODS

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

RESULT

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

CONCLUSION

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

Patent ductus arteriosus: From pharmacology to surgery

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

Pharmacokinetics of Intravenous Paracetamol (Acetaminophen) and Ductus Arteriosus Closure After Premature Birth

In preterm infants, a high risk of hemodynamically significant patent ductus arteriosus (PDA) exists and its persistence is associated with an increased risk of severe morbidity. Current pharmacological options include ibuprofen or indomethacin. However, treatment by indomethacin or ibuprofen of a large PDA was shown to reduce early pulmonary hemorrhage and later medical treatment but had no effect on neonatal death or morbidity. Early prophylactic treatment of ductus arteriosus by paracetamol seems to be an attractive opportunity to reduce life-threatening morbidity. However, there are currently no data regarding the pharmacokinetics (PK) and pharmacodynamics of paracetamol in preterm neonates in this potential new indication. In this study, we aimed to develop a population PK model for paracetamol and investigate the relationship between paracetamol exposure levels and time to contraction of the ductus. Data were modeled using Monolix software. A one-compartment model adequately described the paracetamol concentration-time course. A Weibull model adequately described the time to contraction of the ductus. Our results suggest that the dosage used in this study (i.e., first day 42.5 mg/kg, then 30 mg/kg/day) allows for reaching the maximum inhibition response from paracetamol regarding the time to close the ductus. However, this study pointed out a lower effect of paracetamol on extremely preterm neonates (below 27 weeks). Therefore, a dose-finding study focusing specifically on extremely preterm neonates with treatment efficacy and toxicity is strongly needed.

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

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

Platelet Counts and Patent Ductus Arteriosus in Preterm Infants: An Updated Systematic Review and Meta-Analysis

Background: A meta-analysis published in 2015 showed a significant association between low platelet counts in the first day(s) of life and risk of patent ductus arteriosus (PDA). The meta-analysis pooled data from 11 studies cohorts (3,479 preterm infants). Objective: To update the meta-analysis by adding new studies on the topic and including other platelet parameters different from platelet counts. Methods: PubMed/Medline and Embase databases were searched. Random-effects risk ratios (RR) and differences in means (DM) and 95% confidence intervals (CI) were calculated. Results: We included 31 studies (7,638 infants). Meta-analysis showed that the risk of developing any PDA was significantly associated with platelet counts<150 × 109/L (11 studies, RR 1.58, 95% CI 1.28 to 1.95), and <100 x 109/L (7 studies, RR 1.61, 95% CI 1.14 to 2.28), but not <50 x 109/L (4 studies, RR 1.34, 95% CI 0.77 to 2.32). Risk of developing hemodynamically significant PDA (hsPDA) was significantly associated with platelet counts<150 x 109/L (12 studies, RR 1.33, 95% CI 1.09 to 1.63), and <100 x 109/L (7 studies, RR 1.39, 95% CI 1.06 to 1.82), but not <50 x 109/L (6 studies, RR 1.24, 95% CI 0.86 to 1.79). Infants with hsPDA had significantly lower mean platelet counts (19 studies, DM 22.0 x 109, 95% CI 14.9 to 29.1) and platelet mass (11 studies, DM 214.4, 95% CI 131.2 to 297.5) and significantly higher platelet distribution width (PDW, 9 studies, DM -0.53, 95% CI -1.01 to -0.05) than infants without hsPDA. Meta-analysis could not demonstrate significant differences in mean platelet volume (MPV). Conclusion: Compared to the previous analysis, this updated meta-analysis included 21 additional studies that provide stronger evidence of the association between low platelet counts and PDA/hsPDA. Other platelet parameters such as platelet mass and PDW are also associated with hsPDA risk. However, the low number of platelets may be an epiphenomenon associated with the maturity and clinical stability of preterm infants rather than a contributing factor in the pathogenesis of PDA.

SIMPLE: A Novel Scoring System for Predicting Hemodynamically Significant Patent Ductus Arteriosus Without Echocardiographic Evaluation in Extremely Low Birth Weight Infants

Aim: To develop a novel clinical scoring system for predicting hemodynamically significant patent ductus arteriosus (hsPDA) in extremely low birth weight (ELBW) infants. Methods: A prospective observational study was conducted among ELBW infants born in the study center during a 6-month period. Fourteen items were selected on a literature review basis and weighed by severity on an arbitrary 1-4 scale, the sum of which represented the Scoring preterm Infants for PDA cLinically without Echocardiographic evaluation (SIMPLE) score. The SIMPLE scores were compared at several time points during the first 3 days of life between two groups of patients: those with an hsPDA at echocardiography and those without. Results: A total of 48 ELBW infants were enrolled, of which 30 infants developed hsPDA. The SIMPLE scores of the infants with hsPDA were significantly greater than those of the infants who did not develop hsPDA. Cut-off SIMPLE scores that were significantly associated with detection of symptomatic hsPDA at each evaluation time point were identified. Conclusions: SIMPLE is the first scoring system that depends on the risk factors and clinical findings of ELBW infants for early prediction of hsPDA. It is simple, objective and easy to perform, and it does not require any additional tests and/or echocardiographic evaluation. We suggest that SIMPLE can be used as a screening tool for determining the need for echocardiographic evaluation in ELBW infants in order to minimize the number of unnecessary pediatric cardiology consultations.

Early Urinary Metabolomics in Patent Ductus Arteriosus Anticipates the Fate: Preliminary Data

Introduction: In premature neonates, the persistence of hemodynamically significant ductus arteriosus (hsPDA) can be associated with short- and long-term consequences, impairing their outcome. The correct strategy of management for such condition is under debate, especially regarding contraindications and/or side effects. In recent years, metabolomics was applied to several perinatal, pediatric, and adult conditions to investigate potential biomarkers of disease, which have become useful for early diagnosis and/or therapeutic management. Aim of the Study: The main purpose of our exploratory study was to asses, through ¹H-NMR metabolomics analysis of urinary samples at birth, possible metabolic pathways differentiating, with a significant predictive power, those preterm neonates who will subsequently develop hsPDA and neonates of comparable gestational age (GA) who will undergo spontaneous ductal closure or the persistence of an irrelevant PDA (no-hsPDA). Moreover, we investigated potential prenatal or perinatal clinical factors potentially influencing the development of hsPDA. Materials and Methods: We enrolled n = 35 preterm neonates with GA between 24 and 32 weeks; urinary samples were collected within the first 12 h of life. Patients were closely monitored regarding intensive care, respiratory support, fluid balance and administered drugs; an echocardiogram was performed at 48-72 h. Results: Our results reported a significant correlation between lower GA at birth and the development of hsPDA. Moreover, neonates with GA ≤ 30w developing hsPDA were characterized by lower Apgar scores at 1' and 5', higher rates of perinatal asphyxia, higher need of delivery room resuscitation and subsequent surfactant administration. Interestingly, metabolomics analysis at birth detected a clear separation between the ¹H-NMR urinary spectra of subjects GA ≤ 30w not developing hsPDA (n = 19) and those of subjects born at GA ≤ 30w in which hsPDA was confirmed at 48-72 h of life (n = 5). Conclusions: This is the first study applying metabolomics to investigate the PDA condition. Although preliminary and conducted on a limited sample, our results reveal that metabolomics could be a promising tool in the early identification of hsPDA, potentially superior to the clinical or laboratory predictive tools explored to date and even to the clinical observations and correlations in our sample, through the detection of specific urinary metabolites.