Effects of Prophylactic Indomethacin on Vasopressor-Dependent Hypotension in Extremely Preterm Infants

Impact of Early Hemodynamic Screening on Extremely Preterm Outcomes in a High-Performance Center

Rationale: Increasing survival of extremely preterm infants with a stable rate of severe intraventricular hemorrhage represents a growing health risk for neonates. Objectives: To evaluate the role of early hemodynamic screening (HS) on the risk of death or severe intraventricular hemorrhage. Methods: All eligible patients 22-26+6 weeks' gestation born and/or admitted <24 hours postnatal age were included. As compared with standard neonatal care for control subjects (January 2010-December 2017), patients admitted in the second epoch (October 2018-April 2022) were exposed to HS using targeted neonatal echocardiography at 12-18 hours. Measurements and Main Results: A primary composite outcome of death or severe intraventricular hemorrhage was decided a priori using a 10% reduction in baseline rate to calculate sample size. A total of 423 control subjects and 191 screening patients were recruited with a mean gestation and birth weight of 24.7 ± 1.5 weeks and 699 ± 191 g, respectively. Infants born at 22-23 weeks represented 41% (n = 78) of the HS epoch versus 32% (n = 137) of the control subjects (P = 0.004). An increase in perinatal optimization (e.g., antepartum steroids) but with a decline in maternal health (e.g., increased obesity) was seen in the HS versus control epoch. A reduction in the primary outcome and each of severe intraventricular hemorrhage, death, death in the first postnatal week, necrotizing enterocolitis, and severe bronchopulmonary dysplasia was seen in the screening era. After adjustment for perinatal confounders and time, screening was independently associated with survival free of severe intraventricular hemorrhage (OR 2.09, 95% CI [1.19, 3.66]). Conclusions: Early HS and physiology-guided care may be an avenue to further improve neonatal outcomes; further evaluation is warranted.

Perinatal origins of bronchopulmonary dysplasia-deciphering normal and impaired lung development cell by cell

Bronchopulmonary dysplasia (BPD) is a multifactorial disease occurring as a consequence of premature birth, as well as antenatal and postnatal injury to the developing lung. BPD morbidity and severity depend on a complex interplay between prenatal and postnatal inflammation, mechanical ventilation, and oxygen therapy as well as associated prematurity-related complications. These initial hits result in ill-explored aberrant immune and reparative response, activation of pro-fibrotic and anti-angiogenic factors, which further perpetuate the injury. Histologically, the disease presents primarily by impaired lung development and an arrest in lung microvascular maturation. Consequently, BPD leads to respiratory complications beyond the neonatal period and may result in premature aging of the lung. While the numerous prenatal and postnatal stimuli contributing to BPD pathogenesis are relatively well known, the specific cell populations driving the injury, as well as underlying mechanisms are still not well understood. Recently, an effort to gain a more detailed insight into the cellular composition of the developing lung and its progenitor populations has unfold. Here, we provide an overview of the current knowledge regarding perinatal origin of BPD and discuss underlying mechanisms, as well as novel approaches to study the perturbed lung development.

Patent ductus arteriosus (PDA) and pulmonary morbidity: can early targeted pharmacologic PDA treatment decrease the risk of bronchopulmonary dysplasia?

A persistent left-to-right shunt through a patent ductus arteriosus (PDA) increases the rate of pulmonary hydrostatic fluid filtration, impairs pulmonary mechanics, and prolongs the need for respiratory support. Infants with a moderate/large PDA shunt that persists for more than 7-14 days are at increased risk for developing bronchopulmonary dysplasia (BPD) if they also require invasive ventilation for more than 10 days. In contrast, infants who require invasive ventilation for less than 10 days have similar rates of BPD no matter how long they are exposed to a moderate/large PDA shunt. Although pharmacologic PDA closure decreases the risk of abnormal early alveolar development in preterm baboons that are ventilated for 2 weeks, the findings from recent randomized controlled trials, as well as a quality improvement project, suggest that routine early targeted pharmacologic treatments, as currently employed, do not appear to alter the incidence of BPD in human infants.

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

BACKGROUND

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

GOAL

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

STUDY DESIGN

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

RESULTS

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

CONCLUSIONS

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

IMPACT

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

Prolonged Tracheal Intubation and the Association Between Patent Ductus Arteriosus and Bronchopulmonary Dysplasia: A Secondary Analysis of the PDA-TOLERATE trial

In the PDA-TOLERATE trial, persistent (even for several weeks) moderate to large patent ductus arteriosus (PDA) was not associated with an increased risk of BPD when the infant required <10 days of intubation. However, in infants requiring intubation for ≥10 days, prolonged PDA exposure (≥11 days) was associated with an increased risk of moderate/severe BPD.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

An Observational, Prospective, Multicenter, Registry-Based Cohort Study Comparing Conservative and Medical Management for Patent Ductus Arteriosus

No consensus has been reached on which patent ductus arteriosus (PDAs) in preterm infants require treatment and if so, how, and when they should be treated. A prospective, multicenter, cohort study was conducted to compare the effects of conservative approaches and medical treatment options on ductal closure at discharge, surgical ligation, prematurity-related morbidities, and mortality. Infants between 24^0/7 and 28^6/7 weeks of gestation from 24 neonatal intensive care units were enrolled. Data on PDA management and patients' clinical characteristics were recorded prospectively. Patients with moderate-to-large PDA were compared. Among the 1,193 enrolled infants (26.7 ± 1.4 weeks and 926 ± 243 g), 649 (54%) had no or small PDA, whereas 544 (46%) had moderate-to-large PDA. One hundred thirty (24%) infants with moderate-to-large PDA were managed conservatively, in contrast to 414 (76%) who received medical treatment. Eighty (62%) of 130 infants who were managed conservatively did not receive any rescue treatment and the PDA closure rate was 53% at discharge. There were no differences in the rates of late-onset sepsis, necrotizing enterocolitis (NEC), retinopathy of prematurity, intraventricular hemorrhage (≥Grade 3), surgical ligation, and presence of PDA at discharge between conservatively-managed and medically-treated infants (p > 0.05). Multivariate analysis including perinatal factors showed that medical treatment was associated with increased risk for mortality (OR 1.68, 95% Cl 1.01-2.80, p = 0.046), but decreased risk for BPD or death (BPD/death) (OR 0.59, 95%Cl 0.37-0.92, p = 0.022). The preferred treatment options were ibuprofen (intravenous 36%, oral 31%), and paracetamol (intravenous 26%, oral 7%). Infants who were treated with oral paracetamol had higher rates of NEC and mortality in comparison to other treatment options. Infants treated before postnatal day 7 had higher rates of mortality and BPD/death than infants who were conservatively managed or treated beyond day 7 (p = 0.009 and 0.007, respectively). In preterm infants born at <29 weeks of gestation with moderate-to-large PDA, medical treatment did not show any reduction in the rates of open PDA at discharge, surgical or prematurity-related secondary outcomes. In addition to the high incidence of spontaneous closure of PDA in the first week of life, early treatment (<7 days) was associated with higher rates of mortality and BPD/death.

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

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

Early prediction of a significant patent ductus arteriosus in infants <32 weeks gestational age

BACKGROUND

The optimal thresholds for identification of preterm infants at greatest risk for adverse sequelae related to patent ductus arteriosus have not been well delineated. Our aim was to determine hemodynamic parameters in the first 24 hours using continuous non-invasive vital and structural measurements to predict which infants required PDA treatment in our institution.

METHODS

Retrospective secondary analysis of data from infants born 23 to 32 weeks gestational age with cardiac output and stroke volume via electrical cardiometry, cerebral tissue oximetry measurements, mean arterial blood pressure (BP), heart rate, and oxygen saturation and functional echocardiography results at 12 hours of life were recorded when available (93 percent of subjects).

RESULTS

A total of 292 infants, of which 55 (26±2 weeks, 862±268 grams) were treated for PDA. Treated infants demonstrated increased left ventricular output (p < 0.001) and lower mean BP (p = 0.010). The optimal area under the receiver operating characteristic curve (AUC) for predicting PDA treatment in our all gestations cohort is a mean BP at 15 hours of life of <33 mm Hg (AUC = 0.854, p < 0.001, 95% CI 0.792, 0.916). For infants <28 weeks a mean BP at 13 hours of life of <33 mm Hg (AUC = 0.741, p < 0.050, 95% CI 0.642, 0.839).

CONCLUSIONS

In our cohort increased left ventricular output and lower mean BP predicted a clinically significant PDA requiring treatment.

PDA-TOLERATE Trial: An Exploratory Randomized Controlled Trial of Treatment of Moderate-to-Large Patent Ductus Arteriosus at 1 Week of Age

OBJECTIVE

To compare early routine pharmacologic treatment of moderate-to-large patent ductus arteriosus (PDA) at the end of week 1 with a conservative approach that requires prespecified respiratory and hemodynamic criteria before treatment can be given.

STUDY DESIGN

A total of 202 neonates of <28 weeks of gestation age (mean, 25.8 ± 1.1 weeks) with moderate-to-large PDA shunts were enrolled between age 6 and 14 days (mean, 8.1 ± 2.2 days) into an exploratory randomized controlled trial.

RESULTS

At enrollment, 49% of the patients were intubated and 48% required nasal ventilation or continuous positive airway pressure. There were no differences between the groups in either our primary outcome of ligation or presence of a PDA at discharge (early routine treatment [ERT], 32%; conservative treatment [CT], 39%) or any of our prespecified secondary outcomes of necrotizing enterocolitis (ERT, 16%; CT, 19%), bronchopulmonary dysplasia (BPD) (ERT, 49%; CT, 53%), BPD/death (ERT, 58%; CT, 57%), death (ERT,19%; CT, 10%), and weekly need for respiratory support. Fewer infants in the ERT group met the rescue criteria (ERT, 31%; CT, 62%). In secondary exploratory analyses, infants receiving ERT had significantly less need for inotropic support (ERT, 13%; CT, 25%). However, among infants who were ≥26 weeks gestational age, those receiving ERT took significantly longer to achieve enteral feeding of 120 mL/kg/day (median: ERT, 14 days [range, 4.5-19 days]; CT, 6 days [range, 3-14 days]), and had significantly higher incidences of late-onset non-coagulase-negative Staphylococcus bacteremia (ERT, 24%; CT,6%) and death (ERT, 16%; CT, 2%).

CONCLUSIONS

In preterm infants age <28 weeks with moderate-to-large PDAs who were receiving respiratory support after the first week, ERT did not reduce PDA ligations or the presence of a PDA at discharge and did not improve any of the prespecified secondary outcomes, but delayed full feeding and was associated with higher rates of late-onset sepsis and death in infants born at ≥26 weeks of gestation.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT01958320.

Patent ductus arteriosus, its treatments, and the risks of pulmonary morbidity

A persistent left-to-right shunt through a patent ductus arteriosus (PDA) increases the rate of hydrostatic fluid filtration into the lung's interstitium, impairs pulmonary mechanics, and prolongs the need for mechanical ventilation. In preclinical trials, pharmacologic PDA closure leads to improved alveolarization and minimizes the impaired postnatal alveolar development that is the pathologic hallmark of bronchopulmonary dysplasia (BPD). Although routine prophylactic treatment of a PDA on the day of birth does not appear to offer any more protection against BPD than delaying treatment for 2-3 days, recent evidence from quality improvement trials suggests that early pharmacologic treatment decreases the incidence of BPD compared with a treatment approach that exposes infants to a moderate-to-large PDA shunt for the first 7-10 days after birth. After the first week, routine pharmacologic treatment (compared with continued PDA exposure) no longer appears to alter the course of BPD development. Evidence from epidemiologic, preclinical, and randomized controlled trials demonstrate that early ductus ligation is an independent risk factor for the development of BPD.

Outcomes of Left Ventricular Function According to Treatment Response for a Patent Ductus Arteriosus in Preterm Infants

Background

To evaluate the outcomes of left ventricular (LV) function according to treatment response for a hemodynamically significant patent ductus arteriosus (hsPDA) in preterm infants.

Methods

Echocardiograms of 21 preterm infants born at gestational age < 31 weeks obtained at term-equivalent age were retrospectively studied. Among preterm infants with a hsPDA, 9 underwent ligation after failure of pharmacological closure (ligation group) and 6 experienced successful pharmacological closure (medication group). Six preterm infants without hsPDA (no-hsPDA group) were studied as controls. LV peak longitudinal systolic strain (ε) of each infant was retrospectively obtained from echocardiograms using velocity vector imaging, along with neonatal outcomes.

Results

Pharmacological closures were attempted at postnatal day 2-3. In the ligation group, the median postnatal age at ligation was 20 days. In the ligation group, LV peak longitudinal systolic ε was significantly decreased at term-equivalent age compared to the other groups. Between the medication and no-hsPDA groups, LV peak longitudinal systolic ε did not differ significantly. Among the neonatal outcomes, infants who experienced necrotizing enterocolitis (NEC) showed significantly decreased LV peak longitudinal systolic ε compared to the infants who did not experience NEC .

Conclusion

We speculate that in preterm infants with an hsPDA, in cases of medical treatment failure, early PDA ligation at less than 20 days of postnatal age would be beneficial for preserving LV systolic function.

Prophylactic Indomethacin Compared with Delayed Conservative Management of the Patent Ductus Arteriosus in Extremely Preterm Infants: Effects on Neonatal Outcomes

OBJECTIVE

To determine whether prophylactic indomethacin (PINDO) has more or less morbidity than delayed conservative management of the moderate-to-large patent ductus arteriosus (PDA).

STUDY DESIGN

We performed a prospective double cohort controlled study of infants delivered at ≤27^6/7 weeks gestation (n = 397). From January 2005 through April 2011, all infants were treated with PINDO (n = 247). From May 2011 through August 2016, no infant was treated with indomethacin until at least 8 postnatal days (conservative epoch, n = 150). Echocardiograms were performed on day 7 and at planned intervals until the PDA was small or closed. A single neonatologist prospectively collected all data.

RESULTS

The incidence of moderate-to-large PDA on day 7 and duration of exposure to moderate-to-large PDA were significantly less in the PINDO epoch (incidence = 10%, median = 2 days) than the conservative epoch (incidence = 67%, median = 14 days). Ligation rates were low in both epochs (PINDO = 14%, conservative = 5%). In multivariate analyses, PINDO infants had a significantly lower incidence of bronchopulmonary dysplasia (BPD) (risk ratio = 0.68, CI: 0.46-0.89) and BPD or death (risk ratio= 0.78, CI: 0.62-0.95) than conservative infants. There were no differences between the epochs in death, intraventricular hemorrhage grades 3 and 4, necrotizing enterocolitis, or retinopathy of prematurity receiving treatment. The effects of PINDO on BPD and BPD or death were no longer significant when analyses were adjusted for presence of a moderate-to-large PDA on day 7. The significant effects of PINDO were independent of whether or not a ligation was performed.

CONCLUSIONS

PINDO decreases BPD and BPD or death compared with delayed conservative PDA management. These effects are mediated by closure of the PDA.

Prophylactic Indomethacin Revisited

Persistent patency of the ductus arteriosus (PDA) has challenged neonatologists for more than 40 years.^, Surgical ligation of the ductus was first performed in children nearly 80 years ago and proved that prevention of prolonged exposure to left-to-right shunting through the ductus arteriosus improved pulmonary, cardiac, and systemic outcomes. In the 1970s, the discovery that nonsteroidal anti-inflammatory drugs could induce PDA closure^– and are effective in infants born preterm^, provided neonatologists with a pharmacologic alternative to surgery. The clear advantages, however, of having a medical approach have been clouded by conflicting information on the long-term benefits of treatment, disagreement regarding the clinical indicators that warrant treatment for PDA, optimal drug choice, preferred dosing regimens, and indecision regarding the best time to treat a select population of fragile preterm infants.