Indomethacin prophylaxis for preterm infants: the impact of 2 multicentered randomized controlled trials on clinical practice

Indomethacin Prophylaxis in Preterm Infants: Changes over Time

OBJECTIVE

Our objective was to examine changes in the use of indomethacin prophylaxis in the neonatal intensive care unit (NICU) between 2008 and 2018.

STUDY DESIGN

The design of the study included cohort of 19,715 infants born between 220/7 and 266/7 weeks' gestation from 213 NICUs. A nonparametric trend test evaluated indomethacin prophylaxis and the percentage of sites using any prophylaxis over time. We evaluated the prevalence of indomethacin prophylaxis by the center and the correlation between indomethacin prophylaxis and severe intraventricular hemorrhage prevalence among 12 centers with the largest relative change in indomethacin prophylaxis prevalence.

RESULTS

In total, 16% of infants received indomethacin prophylaxis. The use of indomethacin prophylaxis did not significantly decrease between 2008 and 2018 but it significantly decreased between 2014 and 2018 (p = 0.046). Among 74 centers with ≥10 infants included, 20% increased the use of indomethacin prophylaxis, while 57% decreased the use over the study period. Of the 12 centers with the largest relative change in indomethacin prophylaxis prevalence, 50% showed an inverse correlation between indomethacin prophylaxis prevalence and severe intraventricular hemorrhage, while 50% showed a positive correlation.

CONCLUSION

Receipt of indomethacin prophylaxis remained similar until 2014, decreased from 2014 to 2018, and varied by the center.Key Points · The receipt of indomethacin prophylaxis decreased over time.. · Center change in the use of indomethacin prophylaxis does not correlate with the center prevalence of IVH.. · Variability in the use of indomethacin prophylaxis across centers persists..

Optimizing trajectories of social adaptive competencies after extreme prematurity during the first 1000 days

Over 75% of surviving extremely preterm infants do not have major neurodevelopmental disabilities; however, more than half face difficulties with communication, coordination, attention, learning, social, and executive function abilities. These "minor" challenges can have a negative impact on educational and social outcomes, resulting in physical, behavioral, and social health problems in adulthood. We will review assessment tools for social-emotional and adaptive functional skills in early childhood as these determine family and early childhood supports. We highlight bronchopulmonary dysplasia as an example of the critical intersections of parental wellbeing, medical and developmental adaptive trajectories in infancy and early childhood, and partnerships between child neurologists and community medical and developmental professionals. We examine studies of engaging parents to promote developmental trajectories, with a focus on supporting parent-child interactions that underlie communication, social-adaptive behaviors, and learning in the first 1000 days of life. Recommendations for neurodevelopmental surveillance and screening of extremely preterm infants can also be applied to infants with other risk factors for altered neurodevelopment.

Model for severe intracranial hemorrhage and role of early indomethacin in extreme preterm infants

BACKGROUND

To develop a model for prediction of severe intracranial hemorrhage (ICH) or death based on variables from the first 12 h of age and to compare mortality and morbidities with and without exposure to early indomethacin.

METHODS

This retrospective cohort study included extreme preterm (220/7-266/7 weeks) infants born at National Institute of Child Health and Human Development Neonatal Research Network sites. Primary outcome was a composite of severe ICH and/or death.

RESULTS

Of 4624 infants, 1827 received early indomethacin. Lower gestation, lack of antenatal steroids exposure, lower 1-min Apgar, male sex, and receipt of epinephrine were associated with severe ICH or death. Early indomethacin was associated with a lower risk of patent ductus arteriosus, bronchopulmonary dysplasia, and higher risk of spontaneous intestinal perforation.

CONCLUSIONS

A model for early prediction of severe ICH/death was developed and validated. Early indomethacin was associated with a lower risk of patent ductus arteriosus and bronchopulmonary dysplasia and a higher risk of spontaneous intestinal perforation.

CLINICAL TRIAL REGISTRATION

Not applicable.

IMPACT

Modern data on severe ICH and neonatal morbidities in relation to prophylactic indomethacin are scarce in the published literature. Prophylactic indomethacin was associated with a lower risk of patent ductus arteriosus and bronchopulmonary dysplasia and a higher risk of intestinal perforation. A risk estimator for severe intracranial hemorrhage/death was developed in a large cohort of extremely preterm infants. The risk estimator developed based on a large cohort of patients provides an estimate of severe intracranial bleeding for an individual infant.

Indomethacin Prophylaxis in Preterm Infants: Changes over Time

OBJECTIVE

 Our objective was to examine changes in the use of indomethacin prophylaxis in the neonatal intensive care unit (NICU) between 2008 and 2018.

STUDY DESIGN

 The design of the study included cohort of 19,715 infants born between 220/7 and 266/7 weeks' gestation from 213 NICUs. A nonparametric trend test evaluated indomethacin prophylaxis and the percentage of sites using any prophylaxis over time. We evaluated the prevalence of indomethacin prophylaxis by the center and the correlation between indomethacin prophylaxis and severe intraventricular hemorrhage prevalence among 12 centers with the largest relative change in indomethacin prophylaxis prevalence.

RESULTS

 In total, 16% of infants received indomethacin prophylaxis. The use of indomethacin prophylaxis did not significantly decrease between 2008 and 2018 but it significantly decreased between 2014 and 2018 (p = 0.046). Among 74 centers with ≥10 infants included, 20% increased the use of indomethacin prophylaxis, while 57% decreased the use over the study period. Of the 12 centers with the largest relative change in indomethacin prophylaxis prevalence, 50% showed an inverse correlation between indomethacin prophylaxis prevalence and severe intraventricular hemorrhage, while 50% showed a positive correlation.

CONCLUSION

 Receipt of indomethacin prophylaxis remained similar until 2014, decreased from 2014 to 2018, and varied by the center.Key Points · The receipt of indomethacin prophylaxis decreased over time.. · Center change in the use of indomethacin prophylaxis does not correlate with the center prevalence of IVH.. · Variability in the use of indomethacin prophylaxis across centers persists..

Reduction of Severe Intraventricular Hemorrhage in Preterm Infants: A Quality Improvement Project

OBJECTIVES

The aim of this quality improvement project was to reduce the rate of severe intraventricular hemorrhage (sIVH) by 50% within 3 years for extremely preterm infants born at a children's teaching hospital.

METHODS

A multidisciplinary team developed key drivers for the development of intraventricular hemorrhage in preterm infants. Targeted interventions included the development of potentially better practice guidelines, promoting early noninvasive ventilation, consistent use of rescue antenatal betamethasone, and risk-based indomethacin prophylaxis. The outcome measure was the rate of sIVH. Process measures included the rate of intubation within 24 hours and receipt of rescue betamethasone and risk-based indomethacin prophylaxis. Common markers of morbidity were balancing measures. Data were collected from a quarterly chart review and analyzed with statistical process control charts. The preintervention period was from January 2012 to March 2016, implementation period was from April 2016 to December 2018, and sustainment period was through June 2020.

RESULTS

During the study period, there were 268 inborn neonates born at <28 weeks' gestation or <1000 g (127 preintervention and 141 postintervention). The rate of sIVH decreased from 14% to 1.2%, with sustained improvement over 2 and a half years. Mortality also decreased by 50% during the same time period. This was associated with adherence to process measures and no change in balancing measures.

CONCLUSIONS

A multipronged quality improvement approach to intraventricular hemorrhage prevention, including evidence-based practice guidelines, consistent receipt of rescue betamethasone and indomethacin prophylaxis, and decreasing early intubation was associated with a sustained reduction in sIVH in extremely preterm infants.

Gestational Age-Dependent Variations in Effects of Prophylactic Indomethacin on Brain Injury and Intestinal Injury

OBJECTIVE

To evaluate the impact of prophylactic indomethacin on early death (<10 days after birth) or severe neurologic injury and on early death or spontaneous intestinal perforation by completed weeks of gestational age in neonates born <29 weeks of gestation.

STUDY DESIGN

This was a multicenter, retrospective cohort study of neonates (n = 12 515) born at 23^6/7 weeks of gestational age, admitted to neonatal intensive care units participating in the Canadian Neonatal Network who received prophylactic indomethacin started within the first 12 hours after birth. Univariate and multivariate analysis compared the composite outcomes of early death or severe neurologic injury and early death or spontaneous intestinal perforation.

RESULTS

Of 12 515 eligible neonates, 1435 (11.5%) were exposed to prophylactic indomethacin; recipients were of lower gestational age and birth weight and had greater severity of illness (Score of Neonatal Acute Physiology with Perinatal Extension) on admission compared with nonrecipients. After we adjusted for confounders, prophylactic indomethacin was associated with reduced odds of early death or severe neurologic injury and early death or spontaneous intestinal perforation in neonates born at 23-24 weeks of gestational age. However, prophylactic indomethacin was associated with increased odds of early mortality or spontaneous intestinal perforation for neonates born at 26-28 weeks of gestational age.

CONCLUSIONS

Prophylactic indomethacin use was associated with benefit in neonates born at 23-24 weeks of gestational age, but with harm at 26-28 weeks of gestational age. Given the observation of significantly improved survival, a randomized controlled trial is needed to investigate the effect of prophylactic indomethacin in babies born at 23-25 weeks of gestational age.

Management of Patent Ductus Arteriosus in Premature Infants in 2020

The patent ductus arteriosus (PDA) is the most commonly found cardiac condition in neonates. While there have been several studies and thousands of publications on the topic, the decision to treat the PDA is still strongly debated among cardiologists, surgeons, and neonatologists. This is in part due to the shortage of long-term benefits with the interventions studied. Practice variations still exist within sub-specialties and centers. This article briefly summarizes the history, embryology and histology of the PDA. It also succinctly discusses the hemodynamic significance of a PDA which builds the framework to review all the available literature on PDA closure in premature infants, though not a paradigm shift just yet; it introduces transcatheter PDA closure (TCPC) as a possible armament to the clinician for this age-old problem.

Association of hemoglobin and spontaneous closure of the ductus arteriosus during the transitional period in very low birth weight infants

OBJECTIVES

To determine the association between plasma hemoglobin (HB) at three time-points (birth, postnatal days 0-3 and 0-10) and spontaneous closure of the ductus arteriosus (sDAC).

STUDY DESIGN

A retrospective case-control study of preterm infants born (2013-2016) between 24 and 29 weeks of gestational age (GA) was conducted in a level three perinatal center in Switzerland. We collected hemoglobin at birth, between days 0-3 and 0-10 in two distinct groups: (i) patients treated for a PDA and (ii) patients with spontaneous closure of the ductus arteriosus (sDAC). Antenatal and postnatal demographic data and neonatal morbidity were collected. Bivariate analysis was performed and a stepwise logistic regression was done to investigate factors associated with sDAC.

RESULTS

We reviewed the medical chart of 184 premature infants of whom 146 (79.3%) satisfied eligibility criteria. Of these, 74 (51%) were classified as sDAC. Patients with sDAC were older (GA: 28 vs 27, p < 0.001), more stable (clinical risk index for babies score (CRIB score): 2 vs 5, p < 0.001) and had better clinical outcomes than patients who received treatment for a PDA. Infants in the sDAC group had a higher level of hemoglobin during the first ten postnatal days. Multiple logistic regression analysis revealed that lower HB level (day 0-10) were associated with failure of sDAC (p < 0.05).

CONCLUSIONS

This is one of the first studies to highlight a potential association between hemoglobin during the transitional period and sDAC. The biological nature of this observation requires prospective clarification.

Decreased Incidence of Intraventricular Hemorrhage in Extremely Low Birth Weight Infants Using Customized Circulatory Management to Evaluate the Hemodynamic Change of Patent Ductus Arteriosus

Background: In extremely low birth weight (ELBW) infants, the patent ductus arteriosus (PDA) with left-to-right shunt and an increase in systemic artery resistance may cause increasing preload and afterload of the left ventricle. The immature myocardium in ELBW infants has a limited ability to respond to the change, which leads to hemorrhagic complications. In this study, we detected the hemodynamic change of cardiac performance and applied a clinical strategy to prevent PDA-associated hemorrhagic complications in ELBW infants. Methods: We enrolled ELBW infants at a single medical center in Taiwan. The customized circulatory management was performed by echocardiography after birth until the PDA closed. Inotropic agents were administrated according to the requirements of hemodynamic parameters or clinical conditions. The primary outcomes were hemorrhagic complications including pulmonary hemorrhage and intraventricular hemorrhage (IVH) greater than grade II. The secondary outcomes were the rate of surgical ligation of PDA, mortality, necrotizing enterocolitis, and bronchopulmonary dysplasia. Results: A total of 20 ELBW infants were evaluated by customized circulatory management from 2019 to 2020. We reviewed 35 ELBW infants born between 2017 and 2018 in our hospital, who served as the non-management group. The management group had a significantly lower incidence rate of IVH greater than grade 2 (p = 0.02). Other outcomes showed no significant differences. Dobutamine was prescribed in 8 cases in the management group, and end-systolic wall stress (ESWS) was significantly decreased after Dobutamine administration (p = 0.017). Conclusion: The incidence rate of IVH greater than grade II in ELBW infants decreased after use of customized circulatory management in our study. The strategy of customized circulatory management might be an effective "early target therapy" for hemodynamically significant PDA in high-risk ELBW infants. Inotropic therapy with Dobutamine could be a useful medical choice for improving cardiac function to prevent hemorrhagic complications.

Therapeutic strategy of patent ductus arteriosus in extremely preterm infants

The ductus arteriosus is likely to close without treatment in most infants born at gestational age (GA) > 28 weeks (73%), and those with birth weight > 1000 g (94%). However, the rates of spontaneous ductal closure among less mature or smaller infants with respiratory distress syndrome are not known. Extremely preterm infants born at GA < 28 weeks are associated with a high risk of severe intraventricular hemorrhage (IVH) or pulmonary hemorrhage, which usually occur within 72 h after birth and affect mortality and long-term neurological development. These serious hemorrhagic complications may be closely related to hemodynamic changes caused by a hemodynamically significant patent ductus arteriosus (hs-PDA). While prophylactic indomethacin has been shown to reduce the rates of PDA, PDA ligation, severe IVH and early pulmonary hemorrhage, the available evidence does not support its prophylactic use in preterm infants. Symptomatic or late treatment is associated with lower success rate, and increased complications of a hs-PDA. The issue of "to treat or not to treat a PDA" is controversial. Considering the relationship between the effectiveness and timing of pharmacological treatment, early targeted treatment may be an alternative approach for the early identification of a hs-PDA in specific high-risk patient population, especially infants <26 weeks GA who are at the highest risk of severe IVH or pulmonary hemorrhage. Serial echocardiographic studies can be used to select patients who are candidates for early targeted medical treatment of hs-PDA. Surgical ligation of PDA, and transcatheter closure if proven to be safe, can be used as back-up therapy for patients who fail medical treatment and continue to have cardiopulmonary compromise.

Outcomes of infants with congenital diaphragmatic hernia treated with venovenous versus venoarterial extracorporeal membrane oxygenation: A propensity score approach

PURPOSE

Previous studies comparing extracorporeal membrane oxygenation (ECMO) modality for congenital diaphragmatic hernia (CDH) have not accounted for confounding by indication. We therefore hypothesized that using a propensity score (PS) approach to account for selection bias may identify outcome differences based on ECMO modality for infants with CDH.

METHODS

We utilized ELSO Registry data (2000-2016). Patients with CDH were divided to either venoarterial (VA) or venovenous (VV) ECMO. Patients were matched by PS to control for nonrandom treatment assignment. Subgroup analyses were conducted based on timing of CDH repair relative to ECMO. Primary analysis was the "intent-to-treat" cohort based on the initial ECMO mode. Mortality was the primary outcome, and severe neurologic injury (SNI) was a secondary outcome.

RESULTS

PS matching (3:1) identified 3304 infants (VA = 2470, VV = 834). In the main group, mortality was not different between VA and VV ECMO (OR = 1.01, 95% CI: 0.86-1.18) and there was no difference in SNI between VA and VV (OR = 0.80; 95% CI: 0.63-1.01). For the pre-ECMO CDH repair subgroup, 175 VA cases were matched to 70 VV. In these neonates, mortality was higher for VV compared to VA (OR = 2.10, 95% CI: 1.19-3.69), without any difference in SNI (OR = 1.48; 95% CI: 0.59-3.71). For the subgroup that did not have pre-ECMO CDH repair, 2030 VA cases were matched to 683 VV cases. In this subgroup, VV was associated with 27% lower risk of SNI relative to VA (OR = 0.73, 95% CI: 0.56-0.95) without any difference in mortality (OR = 0.94, 95% CI: 0.79-1.11).

CONCLUSION

This study revalidates that ECMO mode does not significantly affect mortality or SNI in infants with CDH. In the subset of infants who require pre-ECMO CDH repair, VA favors survival, whereas, in the subgroup of infants that did not have pre-ECMO CDH repair, VV favors lower rates of SNI. We conclude that neither mode appears consistently superior across all situations, and clinical judgment should remain a multifactorial decision.

LEVEL OF EVIDENCE

Level III.

International perspective on management of a patent ductus arteriosus: Lessons learned

Whereas association between a patent ductus arteriosus (PDA) and neonatal morbidities has been well described, consensus has not been reached on whether the relationship is causal, on benefit of (or lack of) treatment, on factors guiding the 'need to treat', and on treatment strategies. Trials to date have primarily focused on the narrow outcome of successful ductal closure. Evidence from several retrospective studies has suggested that management may be modified with increased use of conservative treatment. A paradigm shift has resulted in decreased use of treatments to close the PDA in some centres. This approach cites the lack of demonstrable improvement in short- and long-term respiratory and neurodevelopmental outcomes as an argument. This article reviews current understanding of the wide variation in practice at either institutional, regional, national, or international level. It discusses the potential contributors to variability in diagnostic ascertainment and therapeutic intervention.

Changing patterns of patent ductus arteriosus surgical ligation in the United States

Optimal management of patent ductus arteriosus (PDA) is unclear. One treatment, surgical ligation, is associated with adverse outcomes. We reviewed data from the Kids' Inpatient Database (2000-2012) to determine if PDA ligation rates: (1) changed over time, (2) varied geographically, or (3) influenced surgical complication rates. In 2012, 47,900 infants <1500g birth weight were born in the United States, including 2,800 undergoing PDA ligation (5.9%). Ligation was more likely in infants <1000g (85.9% vs. 46.2%), and associated with necrotizing enterocolitis (59.2% vs. 37.5%), BPD (54.6% vs. 15.2%), severe intraventricular hemorrhage (16.4% vs. 5.3%), and hospital transfer (37.6% vs. 16.4%). Ligation rates peaked in 2006 at 87.4 per 1000 hospital births, dropping to 58.8 in 2012, and were consistently higher in Western states. Infants undergoing ligation were more likely to experience comorbidities. Rates of ligation-associated vocal cord paralysis increased over time (1.2-3.9%); however, mortality decreased (12.4-6.5%). Thus, PDA ligation has become less frequent, although infants being ligated are smaller and more medically complex. Despite increase in some complications, mortality rates improved perhaps reflecting advances in care.

Golden hour of neonatal life: Need of the hour

"Golden Hour" of neonatal life is defined as the first hour of post-natal life in both preterm and term neonates. This concept in neonatology has been adopted from adult trauma where the initial first hour of trauma management is considered as golden hour. The "Golden hour" concept includes practicing all the evidence based intervention for term and preterm neonates, in the initial sixty minutes of postnatal life for better long-term outcome. Although the current evidence supports the concept of golden hour in preterm and still there is no evidence seeking the benefit of golden hour approach in term neonates, but neonatologist around the globe feel the importance of golden hour concept equally in both preterm and term neonates. Initial first hour of neonatal life includes neonatal resuscitation, post-resuscitation care, transportation of sick newborn to neonatal intensive care unit, respiratory and cardiovascular support and initial course in nursery. The studies that evaluated the concept of golden hour in preterm neonates showed marked reduction in hypothermia, hypoglycemia, intraventricular hemorrhage (IVH), bronchopulmonary dysplasia (BPD), and retinopathy of prematurity (ROP). In this review article, we will discuss various components of neonatal care that are included in "Golden hour" of preterm and term neonatal care.

Outcomes following indomethacin prophylaxis in extremely preterm infants in an all-referral NICU

OBJECTIVE

We examined data from a contemporary cohort of extreme prematurity (EP) infants admitted to an all-referral Children's Hospital neonatal intensive care unit (NICU) to determine whether prophylactic indomethacin (PI) may continue to benefit these patients.

STUDY DESIGN

An observational study utilizing the small baby ICU data registry that was queried for all EP infants admitted between 2005 and 2014 with documentation of PI use (671 total EP infants; 141 (21%) did not receive PI (control); 530 (79%) received PI (PI). This cohort of EP infants was born at outside hospitals and transferred to our level IV NICU with a mean age on admission of 13 days, well after the PI would have been administered.

RESULTS

No difference existed between the control and PI groups in gestational age, birth weight, severity of illness, other in-hospital outcomes or developmental delay. PI infants had a significantly lower mortality rate (P=0.0004), lower relative risk (RR) for mortality 0.52 (95% confidence interval (CI) 0.37 to 0.73, P=0.0001) and lower RR of developing the combined outcome of death or bronchopulmonary dysplasia (RR 0.91, 95% CI 0.85 to 0.98, P=0.012) when compared with the control group. Notably, there was no significant effect of PI on incidence of severe intraventricular hemorrhage or patent ductus arteriosus ligation.

CONCLUSION

PI administration was associated with improved survival in EP infants referred to a level IV Children's Hospital NICU.

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.

Does ibuprofen treatment in patent ductus arteriosus alter oxygen free radicals in premature infants?

Introduction Ibuprofen is used widely to close patent ductus arteriosus in preterm infants. The anti-inflammatory activity of ibuprofen may also be partly due to its ability to scavenge reactive oxygen species and reactive nitrogen species. We evaluated the interaction between oxidative status and the medical treatment of patent ductus arteriosus with two forms of ibuprofen. Materials and methods This study enrolled newborns of gestational age ⩽32 weeks, birth weight ⩽1500 g, and postnatal age 48-96 hours, who received either intravenous or oral ibuprofen to treat patent ductus arteriosus. Venous blood was sampled before ibuprofen treatment from each patient to determine antioxidant and oxidant concentrations. Secondary samples were collected 24 hours after the end of the treatment. Total oxidant status and total antioxidant capacity were measured using Erel's method.

RESULTS

This prospective randomised study enrolled 102 preterm infants with patent ductus arteriosus. The patent ductus arteriosus closure rate was significantly higher in the oral ibuprofen group (84.6 versus 62%) after the first course of treatment (p=0.011). No significant difference was found between the pre- and post-treatment total oxidant status and total antioxidant capacity in the groups. Discussion Ibuprofen treatment does not change the total oxidant status or total antioxidant capacity. We believe that the effect of ibuprofen treatment in inducing ischaemia overcomes the scavenging effect of ibuprofen.

Effect of prophylactic indomethacin administration and early feeding on spontaneous intestinal perforation in extremely low-birth-weight infants

OBJECTIVE

To determine the effect of concomitant administration of prophylactic indomethacin and early enteral feeds on the risk of spontaneous intestinal perforation (SIP) in extremely low-birth-weight (ELBW) infants, and to describe the variation in prophylactic indomethacin use in Canada.

STUDY DESIGN

A retrospective cohort study of 4268 ELBW infants born at <30 weeks' gestation admitted to Canadian neonatal units between 2010 and 2014 was conducted. Prophylactic indomethacin (I+ or I-, administered within 24 h) and early feeding (E+ or E-, initiated in the first 2 days) exposures were studied concurrently and independently. The primary outcomes were SIP and death before discharge. Adjusted odds ratios (aORs) and 95% confidence intervals (CIs) were calculated.

RESULTS

Compared with the I-/E+ reference group (n=1829), infants in I+/E+ (n=285; aOR 2.92, 95% CI 1.41 to 6.08) and I+/E- (n=213; aOR 2.84, 95% CI 1.35 to 5.98) groups had higher odds of SIP, whereas those in the I-/E- group had similar odds (n=1941; aOR 1.37, 95% CI 0.88 to 2.14). Odds of SIP were higher in the indomethacin exposed group (I+) compared with the unexposed (I-) group when controlled for early feeding (aOR 2.43, 95% CI 1.41 to 4.19), but not in the early feeding group when controlled for indomethacin. The use of prophylactic indomethacin ranged from 0% usage in 13 sites to 78% use in one site.

CONCLUSION

Prophylactic indomethacin was associated with increased odds of SIP independently from early feeding in this cohort; however, early enteral feeding was not associated with SIP. Marked variation in the use of prophylactic indomethacin was identified.

Reflections of the changes in patent ductus arteriosus management during the last 10 years

Despite a large body of scientific evidence on the management of premature infants with a patent ductus arteriosus controversy remains and neonatologists remain challenged for knowing which patient to treat, what is the most optimal timing of treatment and which treatments have a positive impact on both short-term and long-term outcomes. In this review article we discuss the increased body of evidence over the past 10 years, much of which questions the role of treatment and suggests the need to reconsider how haemodynamic significance is adjudicated. In addition, we discuss novel approaches to assessment and diagnosis, and highlight areas for future investigation.

Nonsteroidal anti-inflammatory administration and patent ductus arteriosus ligation, a survey of practice preferences at US children's hospitals

We surveyed neonatal leadership at 46 US children's hospitals via web-based survey to identify local preferences and concerns regarding indomethacin prophylaxis, nonsteroidal anti-inflammatory drug (NSAID) treatment, and patent ductus arteriosus (PDA) ligation. We received a 100 % survey response (N = 46). Practice guidelines for prophylactic indomethacin were reported at 28 % of NICUs, for NSAID treatment of PDA at 39 % and for surgical ligation at 27 %. Respondents noted intra-institutional practice variation for indomethacin prophylaxis (33 %), NSAID treatment (70 %), and PDA ligation (73 %). The majority of institutions did not prescribe indomethacin prophylaxis (72 %). For PDA treatment, indomethacin was preferred over ibuprofen (80 %). We validated our survey results via comparison with billing data as documented in the Pediatric Health Information System (PHIS) database, finding that survey responses directly correlated with local billing data (p < 0.0001). At institutions that did not typically administer NSAIDs for PDA closure or surgical PDA ligation, a lack of evidence for their effectiveness in improving long-term outcomes and the risk of treatment-associated adverse effects were the most often cited reasons.

CONCLUSION

No consensus exists among providers at US children's hospitals regarding prophylactic indomethacin, NSAID treatment, or PDA ligation. Lack of evidence and safety concerns play a prominent role.

WHAT IS KNOWN

• NSAIDs and surgical PDA ligation are efficacious in preventing intraventricular hemorrhage (IVH) and closing PDA in preterm infants, but have not been shown to improve long-term respiratory, neurodevelopmental, or mortality outcomes. What is New: • Practice preferences for indomethacin prophylaxis, NSAID, and surgical PDA treatment vary both among and within institutions. Lack of treatment effectiveness and the risk of adverse effects are major concerns.

Pharmacological Closure of Patent Ductus Arteriosus: Selecting the Agent and Route of Administration

Opinions are divided regarding the management of a persistently patent ductus arteriosus (PDA). Some of the adverse effects associated with a large hemodynamically significant duct, including prolonged ventilation, pulmonary hemorrhage, bronchopulmonary dysplasia (BPD), necrotizing enterocolitis (NEC), intraventricular hemorrhage (IVH), and mortality, indicate that active management of infants with large ductal shunts may sometimes be necessary. Indomethacin and ibuprofen are the two US FDA-approved cyclooxygenase (COX) inhibitors used for the closure of a ductus in preterm babies. Both these drugs are effective in 70-80% of extremely low birthweight infants. Treatment with COX inhibitors may be associated with renal impairment, gastrointestinal hemorrhage, NEC, and spontaneous intestinal perforation when given concurrently with steroids, as well as changes in cerebrovascular auto-regulation. Ibuprofen appears to be a better choice for PDA closure, with a better side effect profile and efficacy that equals that of indomethacin. However, long-term outcome studies of ibuprofen are lacking, and prophylactic ibuprofen is ineffective in decreasing severe IVH. The choice of one drug over the other also depends on local availability of both drugs and the intravenous or enteral preparation. The oral preparation of ibuprofen appears as effective as the intravenous preparation. The use of paracetamol to close a hemodynamically significant PDA has increased in recent years. Paracetamol also decreases prostacyclin synthesis; however, unlike COX inhibitors, it does not have a peripheral vaso-constrictive effect and can be given to infants with contraindications to non-steroidal anti-inflammatory drugs. It appears to have similar efficacy based on limited data available from randomized trials. Until more data are available on efficacy, safety, and long-term outcomes, it cannot be recommended as the first choice.

Transitional Hemodynamics in Preterm Neonates: Clinical Relevance

BACKGROUND

Each newborn enters this world facing tremendous respiratory, hemodynamic and neuroendocrine challenges while going through drastic physiological changes during the process of adaption from fetal to postnatal life. Even though the vast majority of term infants transition smoothly without apparent consequences, this task becomes increasingly arduous for the extremely preterm infant.

METHODS & RESULTS

This article reviews the physiology and pathophysiology of cardiovascular adaptation of the very preterm neonate. In particular it describes the physiology of fetal circulation, summarizes the hemodynamic changes occurring during preterm births and discusses the impact of the most frequently seen clinical scenarios that place additional burden on the premature infant during immediate transition. Finally an emphasis is placed on discussing common clinical dilemmas and practical aspects of developmental hemodynamics such as neonatal hypotension and patent ductus arteriosus; clinical presentations the neonatologist encounters on a daily basis.

CONCLUSION

The review provides a physiology-based view on the hemodynamics of the immediate postnatal transitional period.

A prospective study of maternal preference for indomethacin prophylaxis versus symptomatic treatment of a patent ductus arteriosus in preterm infants

Background

The management of a patent ductus arteriosus in preterm infants continues to be debated among neonatologists due to the absence of concrete evidence that precisely weighs the long term outcomes of active, early intervention against a conservative approach. In the majority of institutions, parents are encouraged to play an active role in the complex, decision –making processes with regard to the care of their infants. The objective of this study is to elicit maternal preferences for indomethacin prophylaxis versus treatment of a patent ductus arteriosus (PDA) in extremely low birth weight (ELBW) infants, utilizing a decision aid instrument (DAI).

Methods

Healthy and high risk pregnant women at 23–28 weeks gestation, and mothers of admitted ELBW infants were enrolled. A computer based, validated DAI was utilized during interviews. The DAI first provides information about prematurity and concurrent morbidities with comprehensive facts of the pros and cons about prophylactic versus treatment options. It subsequently coaches participants how to select values and preferences based on their decisions. A 17-item questionnaire assessed and valued each short and long term morbidity of extreme prematurity and preferred choice for PDA management.

Results

Two hundred ninety nine subjects were enrolled; 75% were healthy women at 23–28 weeks gestation, 19% were high risk and 6% recently delivered an ELBW infant. Eighty-two percent preferred a prophylactic indomethacin strategy versus symptomatic treatment for the management of PDA. Across a spectrum of potential morbidities, the occurrence of severe intraventricular hemorrhage was viewed by mothers as the most un-wanted outcome irrespective of the two proposed options.

Conclusions

In contrast to neonatal practitioners, mothers who used this particular DAI strongly endorsed prophylactic indomethacin versus a treatment intervention for the management of PDA in preterm infants.

Electronic supplementary material

The online version of this article (doi:10.1186/s12887-015-0353-4) contains supplementary material, which is available to authorized users.

Fluid restriction and prophylactic indomethacin in extremely low birth weight infants

Although survival of extremely low birth weight (ELBW) infants dramatically improved over last decades, bronchopulmonary dysplasia (BPD) rate has not changed. The use of indomethacin prophylaxis in ELBW infants results in improved short-term outcomes with no effect on long-term outcomes. The addition of fluid restriction to the indomethacin prophylaxis policy could result in a reduction of BPD and improve long-term survival without neurosensory impairment at 18 months corrected age. To determine the effect of a policy of fluid restriction compared with a policy of no fluid restriction on morbidity and mortality in ELBW infants receiving indomethacin prophylaxis. The standard search strategy for the Cochrane Neonatal Review Group was used. This included search of OVID MEDLINE-National Library of Medicine, EMBASE, and the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 8, 2011). Additional search included conference proceedings, references in articles, and unpublished data. All randomized or quasi-randomized trials that compared fluid restriction and indomethacin prophylaxis vs. indomethacin prophylaxis alone in ELBW infants were included. Standard methods of the Cochrane Neonatal Review Group were planned to assess the methodological quality of the trials. Review Manager 5 software was planned to be used for statistical analysis. We found no randomized controlled trials to investigate the possible interaction between fluid restriction and indomethacin prophylaxis vs. indomethacin prophylaxis alone in ELBW infants. A well-designed randomized trial is needed to address this question.

A predictive model for SIVH risk in preterm infants and targeted indomethacin therapy for prevention

Prophylactic indomethacin may decrease Severe Intraventricular Hemorrhage (SIVH). Our goal was to develop a predictive model for SIVH using parameters available by six hours of age. De-identified data for preterm infants born ≤ 34 weeks gestational age was abstracted from Vermont Oxford Network database. Using clinical variables available by 6 hrs of age the model was developed, and validated. Statistical methods were used to evaluate the ability of the model to discriminate infants with and without SIVH and, to compare observed and predicted risk. The model achieved excellent discrimination as indicated by ROC curve of 0·85. A good agreement was noted between observed and predicted risk (HLtest: p = 0·22). Application of the model to patients receiving indomethacin suggests a benefit at the highest risk levels. We have developed a valid predictive model for predicting SIVH as well as shown that exposure to indomethacin decreases the incidence of SIVH overall.

Pros and cons of patent ductus arteriosus ligation: hemodynamic changes and other morbidities after patent ductus arteriosus ligation

Although surgical ligation of a persistent patent ductus arteriosus resolves the adverse hemodynamic consequences of the systemic-to-pulmonary shunt and may confer some long-term benefits, it is also associated with both immediate and long-term negative effects. The population that benefits from or is harmed by the procedure is not clearly defined. Although indiscriminate ligation of the patent ductus arteriosus in all patients is not supported by the available information, the recent suggestion declaring the ductus harmless is not supported either. As we await the results of appropriately designed randomized control studies to define the indications for ligation, we must use clinical and echocardiographic indicators of a hemodynamically significant ductus arteriosus and thoughtful assessment of each individual patient to help guide us in addressing this complex problem.

Evidence-based use of indomethacin and ibuprofen in the neonatal intensive care unit

Indomethacin and ibuprofen are potent inhibitors of prostaglandin synthesis. Neonates have been exposed to these compounds for more than 3 decades. Indomethacin is commonly used to prevent intraventricular hemorrhage (IVH), and both drugs are prescribed for the treatment or prevention of patent ductus arteriosus (PDA). This review examines the basis for indomethacin and ibuprofen use in the neonatal intensive care population. Despite the call for restrained use of each drug, the most immature infants are likely to need pharmacologic approaches to reduce high-grade IVH, avoid the need for PDA ligation, and preserve the opportunity for an optimal outcome.

A decision aid for considering indomethacin prophylaxis vs. symptomatic treatment of PDA for extreme low birth weight infants

BACKGROUND

Decision Aids (DA) are well established in various fields of medicine. It can improve the quality of decision-making and reduce decisional conflict. In neonatal care, and due to scientific equipoise, neonatologists caring for extreme low birth weight (ELBW) infants are in need to elicit parents' preferences with regard to the use of indomethacin therapy in ELBW infants. We aimed to develop a DA that elicits parents' preferences with regard to indomethacin therapy in ELBW infants.

METHODS

We developed a DA for the use of the indomethacin therapy in ELBW infants according to the Ottawa Decision Support Framework. The development process involved parents, neonatologists, DA developers and decision making experts. A pilot testing with healthy volunteers was conducted through an evaluation questionnaire, a knowledge scale, and a validated decisional conflict scale.

RESULTS

The DA is a computer-based interactive tool. In the first part, the DA provides information about patent ductus arteriosus (PDA) as a disease, the different treatment options, and the benefits and downsides of using indomethacin therapy in preterm infants. In the second part, it coaches the parent in the decision making process through clarifying values and preferences. Volunteers rated 10 out of 13 items of the DA positively and showed significant improvement on both the knowledge scale (p = 0.008) and the decisional conflict scale (p = 0.008).

CONCLUSION

We have developed a computer based DA to assess parental preferences with regard to indomethacin therapy in preterm infants. Future research will involve measurement of parental preferences to guide and augment the clinical decisions in current neonatal practice.

Impact of sepsis on neurodevelopmental outcome in a Swiss National Cohort of extremely premature infants

OBJECTIVE

Neonatal sepsis causes high mortality and morbidity in preterm infants, but less is known regarding the long-term outcome after sepsis. This study aimed to determine the impact of sepsis on neurodevelopment at 2 years' corrected age in extremely preterm infants.

PATIENTS AND METHODS

This was a multicenter Swiss cohort study on infants born between 2000 and 2007 at 24(0/7) to 27(6/7) weeks' gestational age. Neurodevelopmental outcome was assessed with the Bayley Scales of Infant Development-II. Neurodevelopmental impairment (NDI) was defined as a Mental or Psychomotor Developmental Index lower than 70, cerebral palsy (CP), or visual or auditory impairment.

RESULTS

Of 541 infants, 136 (25%) had proven sepsis, 169 (31%) had suspected sepsis, and 236 (44%) had no signs of infection. CP occurred in 14 of 136 (10%) infants with proven sepsis compared with 10 of 236 (4%) uninfected infants (odds ratio [OR]: 2.90 [95% confidence interval (CI): 1.22-6.89]; P = .016). NDI occurred in 46 of 134 (34%) infants with proven sepsis compared with 55 of 235 (23%) uninfected infants (OR: 1.85 [95% CI: 1.12-3.05]; P = .016). Multivariable analysis confirmed that proven sepsis independently increased the risk of CP (OR: 3.23 [95% CI: 1.23-8.48]; P = .017) and NDI (OR: 1.69 [95% CI: 0.96-2.98]; P = .067). In contrast, suspected sepsis was not associated with neurodevelopmental outcome (P > .05). The presence of bronchopulmonary dysplasia, pathologic brain ultrasonography, retinopathy, and sepsis predicted the risk of NDI (P < .0001).

CONCLUSIONS

Proven sepsis significantly contributes to NDI in extremely preterm infants, independent of other risk factors. Better strategies aimed at reducing the incidence of sepsis in this highly vulnerable population are needed.

Role of prophylactic surgical ligation of patent ductus arteriosus in extremely low birth weight infants: Systematic review and implications for clinical practice

Objectives:

To investigate the effectiveness and safety of prophylactic surgical ligation of patent ductus arteriosus (PDA) on mortality and morbidity of preterm infants weighing less than 1000 g at birth.

Materials and Methods:

The study conducted a systematic search of available database from 1996-2008. Retrieved articles were assessed for eligibility and data was abstracted independently by two reviewers. Decisions to include studies for review and the methodological quality of included studies were asssessed in duplicate based on predetermined criteria. No language restrictions were applied.

Results:

Only one eligible study that enrolled 84 extremely low birth weight infants was identified. Prophylactic surgical ligation of PDA resulted in a statistically significant reduction of severe stage II or III necrotizing enterocolitis, [RR 0.25, 95% CI (0.08, 0.83), P value 0.02, number needed to treat 5]. The study, however, found no statistically significant difference in mortality, intraventricular hemorrhage, bronchopulmonary dysplasia, and retinopathy of prematurity.

Conclusions:

Current evidence does not support the use of prophylactic surgical ligation of PDA in the management of the preterm infants.

Fluid restriction and prophylactic indomethacin versus prophylactic indomethacin alone for prevention of morbidity and mortality in extremely low birth weight infants

BACKGROUND

Although survival of extremely low birth weight (ELBW) infants has dramatically improved over the last decades, the rate of bronchopulmonary dysplasia (BPD) has not changed. The use of indomethacin prophylaxis in ELBW infants results in improved short-term outcomes with no effect on long-term outcomes. The addition of fluid restriction to the indomethacin prophylaxis policy could result in a reduction of BPD and improve long-term survival without neurosensory impairment at eighteen months corrected age.

OBJECTIVES

To determine the effect of a policy of fluid restriction compared with a policy of no fluid restriction on morbidity and mortality in ELBW infants receiving indomethacin prophylaxis.

SEARCH STRATEGY

We used the standard search strategy for the Cochrane Neonatal Review Group (CNRG). This included searches of the Cochrane Central Register of Controlled Trials (CENTRAL) ( The Cochrane Library 2010, Issue 1), MEDLINE (1966 to December 2010), and EMBASE (1980 to December 2010). Additional searches included conference proceedings, references in articles and unpublished data.

SELECTION CRITERIA

We planned to include all randomized or quasi-randomized trials that compared fluid restriction and indomethacin prophylaxis versus indomethacin prophylaxis alone in ELBW infants.

DATA COLLECTION AND ANALYSIS

If we had identified any eligible studies, we would have assessed the methodological quality of the trials using the standard methods of the CNRG. We planned to use Review Manager 5 software for statistical analysis.

MAIN RESULTS

We did not identify any eligible trials.

AUTHORS' CONCLUSIONS

We found no randomized controlled trials to investigate the possible interaction between fluid restriction and indomethacin prophylaxis versus indomethacin prophylaxis alone in ELBW infants. A well-designed randomized trial is needed to address this question.

Effects of prophylactic indomethacin in extremely low-birth-weight infants with and without adequate exposure to antenatal corticosteroids

OBJECTIVE

To examine whether treatment with antenatal corticosteroids modifies the immediate and long-term effects of prophylactic indomethacin sodium trihydrate in extremely low-birth-weight infants.

DESIGN

Post hoc subgroup analysis of data from the Trial of Indomethacin Prophylaxis in Preterms.

SETTING

Thirty-two neonatal intensive care units in Canada, the United States, Australia, New Zealand, and Hong Kong.

PARTICIPANTS

A total of 1195 infants with birth weights of 500 to 999 g and known exposure to antenatal corticosteroids. We defined as adequate any exposure to antenatal corticosteroids that occurred at least 24 hours before delivery.

INTERVENTION

Indomethacin or placebo intravenously once daily for the first 3 days.

OUTCOME MEASURES

Death or survival to 18 months with cerebral palsy, cognitive delay, severe hearing loss, or bilateral blindness; severe periventricular and intraventricular hemorrhage; patent ductus arteriosus; and surgical closure of a patent ductus arteriosus.

RESULTS

Of the 1195 infants in this analysis cohort, 670 had adequate and 525 had inadequate exposure to antenatal corticosteroids. There was little statistical evidence of heterogeneity in the effects of prophylactic indomethacin between the subgroups for any of the outcomes. The adjusted P values for interaction were as low as .15 for the outcome of death or impairment at 18 months and as high as .80 for the outcome of surgical duct closure.

CONCLUSION

We find little evidence that the effects of prophylactic indomethacin vary in extremely low-birth-weight infants with and without adequate exposure to antenatal corticosteroids. Trial Registration clinicaltrials.gov Identifier: NCT00009646.

Indomethacin prophylaxis revisited: changing practice and supportive evidence

Important short-term intermediate outcomes such as patent ductus arteriosus (PDA), severe intraventricular haemorrhage, surgical ligation of PDA and serious pulmonary haemorrhage correlate with worse neurosensory outcomes in extreme low birth weight infants. Indomethacin prophylaxis has been shown to significantly prevent such outcomes. However, this positive effect did not translate into neither prevention of bronchopulmonary dysplasia nor long-term neurosensory outcome. The indomethacin prophylaxis story is indeed a puzzling one to neonatal practitioners. We present a summary of evidence and possible explanations to the lack of appreciated long-term effect of indomethacin prophylaxis. As the trial of indomethacin prophylaxis for preterms trial is a major contributor to current evidence, a detailed critical analysis of its methodology is presented. Methodological concerns such as the use of a composite outcome, statistical power, anticipated side effects of indomethacin prophylaxis and lack of predictive validity of cognitive delay measurements are presented.

CONCLUSION

Conclusive evidence of indomethacin prophylaxis use in extreme low birth weight infants is still lacking. Future research should put more emphasis on parental preferences, synergistic effect of indomethacin prophylaxis and fluid restriction and early targeted approach to PDA management.

Should we definitively abandon prophylaxis for patent ductus arteriosus in preterm new-borns?

Although the prophylactic administration of indomethacin in extremely low-birth weight infants reduces the frequency of patent ductus arteriosus and severe intraventricular hemorrhage, it does not appear to provide any long-term benefit in terms of survival without neurosensory and cognitive outcomes. Considering the increased drug-induced reduction in renal, intestinal, and cerebral blood flow, the use of prophylaxis cannot be routinely recommended in preterm neonates. However, a better understanding of the genetic background of each infant may allow for individualized prophylaxis using NSAIDs and metabolomics.

Patent ductus arteriosus in the preterm infant: to treat or not to treat?

Pharmacological and/or surgical closure of a hemodynamically significant patent ductus arteriosus (PDA) in the very preterm infant has been the standard of care over the past few decades. However, the rationale for closure of PDA has recently been challenged. In this article, the factors that have fueled the controversy of the approach to the management of PDA and the gap in our knowledge are reviewed in detail. In addition, the pros and cons of the different treatment strategies applied in clinical care are evaluated with a focus on discussing the available evidence in the literature.

Does indomethacin for closure of patent ductus arteriosus affect cerebral function?

OBJECTIVE

To study whether indomethacin used in conventional dose for closure of patent ductus arteriosus affects cerebral function measured by electroencephalograms (EEG) evaluated by quantitative measures.

STUDY DESIGN

Seven premature neonates with haemodynamically significant persistent ductus arteriosus were recruited. EEG were recorded before, during and after an intravenous infusion of 0.2 mg/kg indomethacin over 10 min. The EEG was analysed by two methods with different degrees of complexity for the amount of low-activity periods (LAP, "suppressions") as an indicator of affection of cerebral function.

RESULTS

Neither of the two methods identified any change in the amount of LAPs in the EEG as compared to before the indomethacin infusion.

CONCLUSION

Indomethacin in conventional dose for closure of patent ductus arteriosus does not affect cerebral function as evaluated by quantitative EEG.

Patent ductus arteriosus of the preterm infant

A persistently patent ductus arteriosus (PDA) in preterm infants can have significant clinical consequences, particularly during the recovery period from respiratory distress syndrome. With improvement of ventilation and oxygenation, the pulmonary vascular resistance decreases early and rapidly, especially in very immature infants with extremely low birth weight (<1000 g). Subsequently, the left-to-right shunt through the ductus arteriosus (DA) is augmented, thereby increasing pulmonary blood flow, which leads to pulmonary edema and overall worsening of cardiopulmonary status. Prolonged ventilation, with the potential risks of volutrauma, barotrauma, and hyperoxygenation, is strongly associated with the development and severity of bronchopulmonary dysplasia/chronic lung disease. Substantial left-to-right shunting through the ductus may also increase the risk of intraventricular hemorrhage, necrotizing enterocolitis, and death. Postnatal ductal closure is regulated by exposure to oxygen and vasodilators; the ensuing vascular responses, mediated by potassium channels, voltage-gated calcium channels, mitochondrial-derived reactive oxygen species, and endothelin 1, depend on gestational age. Platelets are recruited to the luminal aspect of the DA during closure and probably promote thrombotic sealing of the constricted DA. Currently, it is unclear whether and when a conservative, pharmacologic, or surgical approach for PDA closure may be advantageous. Furthermore, it is unknown if prophylactic and/or symptomatic PDA therapy will cause substantive improvements in outcome. In this article we review the mechanisms underlying DA closure, risk factors and comorbidities of significant DA shunting, and current clinical evidence and areas of uncertainty in the diagnosis and treatment of PDA of the preterm infant.

Renal Side Effects of Non-Steroidal Anti-Inflammatory Drugs in Neonates

Non-steroidal anti-inflammatory drugs like ibuprofen or indomethacin are commonly prescribed drugs to induce pharmacologic closure of a patent ductus arteriosus in preterm neonates. Based on a recently published Cochrane meta-analysis, both drugs are equally effective to induce closure. Drug choice can therefore be based on differences in side effects or pharmaco-economic arguments. The current review quantifies the negative impact of either ibuprofen or indomethacin on renal function, including diuresis, glomerular filtration rate and renal tubular function. Both ibuprofen and indomethacin have a quantifiable impact on renal function. However, compared to ibuprofen, the negative impact of indomethacin is more pronounced.

Genetic contribution to patent ductus arteriosus in the premature newborn

BACKGROUND

The most common congenital heart disease in the newborn population, patent ductus arteriosus, accounts for significant morbidity in preterm newborns. In addition to prematurity and environmental factors, we hypothesized that genetic factors play a significant role in this condition.

OBJECTIVE

The objective of this study was to quantify the contribution of genetic factors to the variance in liability for patent ductus arteriosus in premature newborns.

PATIENTS AND METHODS

A retrospective study (1991-2006) from 2 centers was performed by using zygosity data from premature twins born at < or =36 weeks' gestational age and surviving beyond 36 weeks' postmenstrual age. Patent ductus arteriosus was diagnosed by echocardiography at each center. Mixed-effects logistic regression was used to assess the effect of specific covariates. Latent variable probit modeling was then performed to estimate the heritability of patent ductus arteriosus, and mixed-effects probit modeling was used to quantify the genetic component.

RESULTS

We obtained data from 333 dizygotic twin pairs and 99 monozygotic twin pairs from 2 centers (Yale University and University of Connecticut). Data on chorioamnionitis, antenatal steroids, gestational age, body weight, gender, respiratory distress syndrome, patent ductus arteriosus, necrotizing enterocolitis, oxygen supplementation, and bronchopulmonary dysplasia were comparable between monozygotic and dizygotic twins. We found that gestational age, respiratory distress syndrome, and institution were significant covariates for patent ductus arteriosus. After controlling for specific covariates, genetic factors or the shared environment accounted for 76.1% of the variance in liability for patent ductus arteriosus.

CONCLUSIONS

Preterm patent ductus arteriosus is highly familial (contributed to by genetic and environmental factors), with the effect being mainly environmental, after controlling for known confounders.

Treatment of patent ductus arteriosus: indomethacin or ibuprofen?

Persistent patent ductus arteriosus (PDA) in preterm infants can result in serious hemodynamic changes causing respiratory, gastrointestinal and renal morbidities if not treated within the first week of life. The treatment options available are a conservative approach, pharmacological treatment with cyclo-oxygenase (COX) inhibitors and surgical ligation. The COX inhibitors approved for use in the United States are indomethacin and ibuprofen lysine. Both of these drugs are equally effective in closing the PDA. Subtle differences exist between these two preparations. Indomethacin has a protective effect on the incidence of intraventricular hemorrhage (IVH) but reduces the blood flow to the kidneys and the brain. Ibuprofen is less toxic but has no effect on IVH. Efficacy of pharmacological treatment is influenced by timing of initiation of therapy. Surgical treatment is the only option when pharmacological treatment fails to close the PDA in symptomatic infants. Long-term neurological and respiratory morbidities are associated with surgical ligation. This paper reviews these medical considerations in the treatment options for PDA in premature infants.

Pharmacoeconomics of Surgical Interventions vs. Cyclooxygenase Inhibitors for the Treatment of Patent Ductus Arteriosus

Management of neonatal patent ductus arteriosus (PDA) often is resource-intensive and costly. Therefore, it is in hospitals' best interests to ensure the most cost-efficient use of associated resources. Clinical status, comorbidities, and response to prior therapy are considered in selecting the most appropriate intervention for PDA management. Currently, supportive measures (e.g., fluid restriction), surgical ligation, and pharmacologically based medical therapy are the primary treatment modalities for correcting PDA. Medical therapy, which comprises a small percentage (2.0%–5.0%)1 of overall PDA treatment expenses in the United States, consists of either of the 2 intravenous (IV) cyclooxygenase (COX) inhibitors: IV indomethacin and the newly available IV ibuprofen lysine. Although IV COX inhibitors represent a small portion of medical expenses, their benefits appear to be considerable. Pharmacoeconomic studies have evaluated indomethacin's beneficial impact on cost-effectiveness per quality-adjusted life year in PDA prophylaxis; however, no analysis to date prospectively assesses the effect of COX inhibitors on resource use or expenses in treating PDA. Such analysis is desirable and should consider efficacy and safety outcomes, impact on health care resource use and length of stay (LOS), and any differential effects of the agents' safety profiles; notably, IV indomethacin adversely affects renal and mesenteric blood flow and increases serum creatinine and oliguria significantly more than IV ibuprofen. These observations lay the foundation to conduct studies assessing the influence of these differences on resource use, LOS and expenses associated with PDA management.