Ibuprofen for the prevention of patent ductus arteriosus in preterm and/or low birth weight infants

Procedural closure of the patent ductus arteriosus in preterm infants: a clinical practice guideline

IMPORTANCE

Transcatheter closure of the patent ductus arteriosus (PDA) is being increasingly adopted as an alternative to surgical PDA closure in preterm infants.

OBJECTIVE

To develop rigorous clinical practice guideline recommendations on procedural PDA closure in preterm infants.

METHODS

The principles of the GRADE (Grading of Recommendations Assessment, Development and Evaluation) Evidence-to-Decision (EtD) framework were used to develop the guideline recommendations. An e-Delphi survey of 45 experts was conducted and recommendations that reached ≥75% agreement were accepted as consensus.

MAIN RECOMMENDATIONS

Procedural PDA closure may be considered in extremely preterm infants (<28 weeks gestational age) requiring invasive mechanical ventilation >10 postnatal days and confirmed to have a large hemodynamically significant PDA, at centers with high local rates of death and/or bronchopulmonary dysplasia (conditional recommendation). If sufficient institutional expertise is available and patient characteristics are suitable, transcatheter PDA closure may be considered as the preferred approach over PDA ligation (conditional recommendation).

Pharmacological pain and sedation interventions for the prevention of intraventricular hemorrhage in preterm infants on assisted ventilation - an overview of systematic reviews

BACKGROUND

Germinal matrix hemorrhage and intraventricular hemorrhage (GMH-IVH) may contribute to neonatal morbidity and mortality and result in long-term neurodevelopmental sequelae. Appropriate pain and sedation management in ventilated preterm infants may decrease the risk of GMH-IVH; however, it might be associated with harms.

OBJECTIVES

To summarize the evidence from systematic reviews regarding the effects and safety of pharmacological interventions related to pain and sedation management in order to prevent GMH-IVH in ventilated preterm infants.

METHODS

We searched the Cochrane Library August 2022 for reviews on pharmacological interventions for pain and sedation management to prevent GMH-IVH in ventilated preterm infants (< 37 weeks' gestation). We included Cochrane Reviews assessing the following interventions administered within the first week of life: benzodiazepines, paracetamol, opioids, ibuprofen, anesthetics, barbiturates, and antiadrenergics. Primary outcomes were any GMH-IVH (aGMH-IVH), severe IVH (sIVH), all-cause neonatal death (ACND), and major neurodevelopmental disability (MND). We assessed the methodological quality of included reviews using the AMSTAR-2 tool. We used GRADE to assess the certainty of evidence.

MAIN RESULTS

We included seven Cochrane Reviews and one Cochrane Review protocol. The reviews on clonidine and paracetamol did not include randomized controlled trials (RCTs) matching our inclusion criteria. We included 40 RCTs (3791 infants) from reviews on paracetamol for patent ductus arteriosus (3), midazolam (3), phenobarbital (9), opioids (20), and ibuprofen (5). The quality of the included reviews was high. The certainty of the evidence was moderate to very low, because of serious imprecision and study limitations. Germinal matrix hemorrhage-intraventricular hemorrhage (any grade) Compared to placebo or no intervention, the evidence is very uncertain about the effects of paracetamol on aGMH-IVH (risk ratio (RR) 0.89, 95% confidence interval (CI) 0.38 to 2.07; 2 RCTs, 82 infants; very low-certainty evidence); midazolam may result in little to no difference in the incidence of aGMH-IVH (RR 1.68, 95% CI 0.87 to 3.24; 3 RCTs, 122 infants; low-certainty evidence); the evidence is very uncertain about the effect of phenobarbital on aGMH-IVH (RR 0.99, 95% CI 0.83 to 1.19; 9 RCTs, 732 infants; very low-certainty evidence); opioids may result in little to no difference in aGMH-IVH (RR 0.85, 95% CI 0.65 to 1.12; 7 RCTs, 469 infants; low-certainty evidence); ibuprofen likely results in little to no difference in aGMH-IVH (RR 0.99, 95% CI 0.81 to 1.21; 4 RCTs, 759 infants; moderate-certainty evidence). Compared to ibuprofen, the evidence is very uncertain about the effects of paracetamol on aGMH-IVH (RR 1.17, 95% CI 0.31 to 4.34; 1 RCT, 30 infants; very low-certainty evidence). Compared to midazolam, morphine may result in a reduction in aGMH-IVH (RR 0.28, 95% CI 0.09 to 0.87; 1 RCT, 46 infants; low-certainty evidence). Compared to diamorphine, the evidence is very uncertain about the effect of morphine on aGMH-IVH (RR 0.65, 95% CI 0.40 to 1.07; 1 RCT, 88 infants; very low-certainty evidence). Severe intraventricular hemorrhage (grade 3 to 4) Compared to placebo or no intervention, the evidence is very uncertain about the effect of paracetamol on sIVH (RR 1.80, 95% CI 0.43 to 7.49; 2 RCTs, 82 infants; very low-certainty evidence) and of phenobarbital (grade 3 to 4) (RR 0.91, 95% CI 0.66 to 1.25; 9 RCTs, 732 infants; very low-certainty evidence); opioids may result in little to no difference in sIVH (grade 3 to 4) (RR 0.98, 95% CI 0.71 to 1.34; 6 RCTs, 1299 infants; low-certainty evidence); ibuprofen may result in little to no difference in sIVH (grade 3 to 4) (RR 0.82, 95% CI 0.54 to 1.26; 4 RCTs, 747 infants; low-certainty evidence). No studies on midazolam reported this outcome. Compared to ibuprofen, the evidence is very uncertain about the effects of paracetamol on sIVH (RR 2.65, 95% CI 0.12 to 60.21; 1 RCT, 30 infants; very low-certainty evidence). Compared to midazolam, the evidence is very uncertain about the effect of morphine on sIVH (grade 3 to 4) (RR 0.08, 95% CI 0.00 to 1.43; 1 RCT, 46 infants; very low-certainty evidence). Compared to fentanyl, the evidence is very uncertain about the effect of morphine on sIVH (grade 3 to 4) (RR 0.59, 95% CI 0.18 to 1.95; 1 RCT, 163 infants; very low-certainty evidence). All-cause neonatal death Compared to placebo or no intervention, the evidence is very uncertain about the effect of phenobarbital on ACND (RR 0.94, 95% CI 0.51 to 1.72; 3 RCTs, 203 infants; very low-certainty evidence); opioids likely result in little to no difference in ACND (RR 1.12, 95% CI 0.80 to 1.55; 5 RCTs, 1189 infants; moderate-certainty evidence); the evidence is very uncertain about the effect of ibuprofen on ACND (RR 1.00, 95% CI 0.38 to 2.64; 2 RCTs, 112 infants; very low-certainty evidence). Compared to midazolam, the evidence is very uncertain about the effect of morphine on ACND (RR 0.31, 95% CI 0.01 to 7.16; 1 RCT, 46 infants; very low-certainty evidence). Compared to diamorphine, the evidence is very uncertain about the effect of morphine on ACND (RR 1.17, 95% CI 0.43 to 3.19; 1 RCT, 88 infants; very low-certainty evidence). Major neurodevelopmental disability Compared to placebo, the evidence is very uncertain about the effect of opioids on MND at 18 to 24 months (RR 2.00, 95% CI 0.39 to 10.29; 1 RCT, 78 infants; very low-certainty evidence) and at five to six years (RR 1.6, 95% CI 0.56 to 4.56; 1 RCT, 95 infants; very low-certainty evidence). No studies on other drugs reported this outcome.

AUTHORS' CONCLUSIONS

None of the reported studies had an impact on aGMH-IVH, sIVH, ACND, or MND. The certainty of the evidence ranged from moderate to very low. Large RCTs of rigorous methodology are needed to achieve an optimal information size to assess the effects of pharmacological interventions for pain and sedation management for the prevention of GMH-IVH and mortality in preterm infants. Studies might compare interventions against either placebo or other drugs. Reporting of the outcome data should include the assessment of GMH-IVH and long-term neurodevelopment.

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.

Interventions for patent ductus arteriosus (PDA) in preterm infants: an overview of Cochrane Systematic Reviews

BACKGROUND

Patent ductus arteriosus (PDA) is associated with significant morbidity and mortality in preterm infants. Several non-pharmacological, pharmacological, and surgical approaches have been explored to prevent or treat a PDA.

OBJECTIVES

To summarise Cochrane Neonatal evidence on interventions (pharmacological or surgical) for the prevention of PDA and related complications, and interventions for the management of asymptomatic and symptomatic PDA in preterm infants.

METHODS

We searched the Cochrane Database of Systematic Reviews on 20 October 2022 for ongoing and published Cochrane Reviews on the prevention and treatment of PDA in preterm (< 37 weeks' gestation) or low birthweight (< 2500 g) infants. We included all published Cochrane Reviews assessing the following categories of interventions: pharmacological therapy using prostaglandin inhibitor drugs (indomethacin, ibuprofen, and acetaminophen), adjunctive pharmacological interventions, invasive PDA closure procedures, and non-pharmacological interventions. Two overview authors independently checked the eligibility of the reviews retrieved by the search, and extracted data from the included reviews using a predefined data extraction form. Any disagreements were resolved by discussion with a third overview author. Two overview authors independently assessed the methodological quality of the included reviews using the AMSTAR 2 (A MeaSurement Tool to Assess systematic Reviews) tool. We reported the GRADE certainty of evidence as assessed by the respective review authors using summary of findings tables.

MAIN RESULTS

We included 16 Cochrane Reviews, corresponding to 138 randomised clinical trials (RCT) and 11,856 preterm infants, on the prevention and treatment of PDA in preterm infants. One of the 16 reviews had no included studies, and therefore, did not contribute to the results. Six reviews reported on prophylactic interventions for the prevention of PDA and included pharmacological prophylaxis with prostaglandin inhibitor drugs, prophylactic surgical PDA ligation, and non-pharmacologic interventions (chest shielding during phototherapy and restriction of fluid intake); one review reported on the use of indomethacin for the management of asymptomatic PDA; nine reviews reported on interventions for the management of symptomatic PDA, and included pharmacotherapy with prostaglandin inhibitor drugs in various routes and dosages, surgical PDA ligation, and adjunct therapies (use of furosemide and dopamine in conjunction with indomethacin). The quality of reviews varied. Two reviews were assessed to be high quality, seven reviews were of moderate quality, five of low quality, while two reviews were deemed to be of critically low quality. For prevention of PDA, prophylactic indomethacin reduces severe intraventricular haemorrhage (IVH; relative risk (RR) 0.66, 95% confidence interval (CI) 0.53 to 0.82; 14 RCTs, 2588 infants), and the need for invasive PDA closure (RR 0.51, 95% CI 0.37 to 0.71; 8 RCTs, 1791 infants), but it does not appear to affect the composite outcome of death or moderate/severe neurodevelopmental disability (RR 1.02, 95% CI 0.90 to 1.15; 3 RCTs, 1491 infants). Prophylactic ibuprofen probably marginally reduces severe IVH (RR 0.67, 95% CI 0.45 to 1.00; 7 RCTs, 925 infants; moderate-certainty evidence), and the need for invasive PDA closure (RR 0.46, 95% CI 0.22 to 0.96; 7 RCTs, 925 infants; moderate-certainty evidence). The evidence is very uncertain on the effect of prophylactic acetaminophen on severe IVH (RR 1.09, 95% CI 0.07 to 16.39; 1 RCT, 48 infants). Necrotising enterocolitis (NEC) was lower with both prophylactic surgical ligation (RR 0.25, 95% CI 0.08 to 0.83; 1 RCT, 84 infants), and fluid restriction (RR 0.43, 95% CI 0.21 to 0.87; 4 RCTs, 526 infants). For treatment of asymptomatic PDA, indomethacin appears to reduce the development of symptomatic PDA post-treatment (RR 0.36, 95% CI 0.19 to 0.68; 3 RCTs, 97 infants; quality of source review: critically low). For treatment of symptomatic PDA, all available prostaglandin inhibitor drugs appear to be more effective in closing a PDA than placebo or no treatment (indomethacin: RR 0.30, 95% CI 0.23 to 0.38; 10 RCTs, 654 infants; high-certainty evidence; ibuprofen: RR 0.62, 95% CI 0.44 to 0.86; 2 RCTs, 206 infants; moderate-certainty evidence; early administration of acetaminophen: RR 0.35, 95% CI 0.23 to 0.53; 2 RCTs, 127 infants; low-certainty evidence). Oral ibuprofen appears to be more effective in PDA closure than intravenous (IV) ibuprofen (RR 0.38, 95% CI 0.26 to 0.56; 5 RCTs, 406 infants; moderate-certainty evidence). High-dose ibuprofen appears to be more effective in PDA closure than standard-dose ibuprofen (RR 0.37, 95% CI 0.22 to 0.61; 3 RCTs, 190 infants; moderate-certainty evidence). With respect to adverse outcomes, compared to indomethacin administration, NEC appears to be lower with ibuprofen (any route; RR 0.68, 95% CI 0.49 to 0.94; 18 RCTs, 1292 infants; moderate-certainty evidence), oral ibuprofen (RR 0.41, 95% CI 0.23 to 0.73; 7 RCTs, 249 infants; low-certainty evidence), and with acetaminophen (RR 0.42, 95% CI 0.19 to 0.96; 4 RCTs, 384 infants; low-certainty evidence). However, NEC appears to be increased with a prolonged course of indomethacin versus a shorter course (RR 1.87, 95% CI 1.07 to 3.27; 4 RCTs, 310 infants).

AUTHORS' CONCLUSIONS

This overview summarised the evidence from 16 Cochrane Reviews of RCTs regarding the effects of interventions for the prevention and treatment of PDA in preterm infants. Prophylactic indomethacin reduces severe IVH, but does not appear to affect the composite outcome of death or moderate/severe neurodevelopmental disability. Prophylactic ibuprofen probably marginally reduces severe IVH (moderate-certainty evidence), while the evidence is very uncertain on the effect of prophylactic acetaminophen on severe IVH. All available prostaglandin inhibitor drugs appear to be effective in symptomatic PDA closure compared to no treatment (high-certainty evidence for indomethacin; moderate-certainty evidence for ibuprofen; low-certainty evidence for early administration of acetaminophen). Oral ibuprofen appears to be more effective in PDA closure than IV ibuprofen (moderate-certainty evidence). High dose ibuprofen appears to be more effective in PDA closure than standard-dose ibuprofen (moderate-certainty evidence). There are currently two ongoing reviews, one on fluid restriction for symptomatic PDA, and the other on invasive management of PDA in preterm infants.

Non-opioid analgesics for procedural pain in neonates

BACKGROUND

Neonates are an extremely vulnerable patient population, with 6% to 9% admitted to the neonatal intensive care unit (NICU) following birth. Neonates admitted to the NICU will undergo multiple painful procedures per day throughout their stay. There is increasing evidence that frequent and repetitive exposure to painful stimuli is associated with poorer outcomes later in life. To date, a wide variety of pain control mechanisms have been developed and implemented to address procedural pain in neonates. This review focused on non-opioid analgesics, specifically non-steroidal anti-inflammatory drugs (NSAIDs) and N-methyl-D-aspartate (NMDA) receptor antagonists, which alleviate pain through inhibiting cellular pathways to achieve analgesia.  The analgesics considered in this review show potential for pain relief in clinical practice; however, an evidence summation compiling the individual drugs they comprise and outlining the benefits and harms of their administration is lacking. We therefore sought to summarize the evidence on the level of pain experienced by neonates both during and following procedures; relevant drug-related adverse events, namely episodes of apnea, desaturation, bradycardia, and hypotension; and the effects of combinations of drugs.  As the field of neonatal procedural pain management is constantly evolving, this review aimed to ascertain the scope of non-opioid analgesics for neonatal procedural pain to provide an overview of the options available to better inform evidence-based clinical practice.  OBJECTIVES: To determine the effects of non-opioid analgesics in neonates (term or preterm) exposed to procedural pain compared to placebo or no drug, non-pharmacological intervention, other analgesics, or different routes of administration.

SEARCH METHODS

We searched the Cochrane Library (CENTRAL), PubMed, Embase, and two trial registries in June 2022. We screened the reference lists of included studies for studies not identified by the database searches.

SELECTION CRITERIA

We included all randomized controlled trials (RCTs), quasi-RCTs, and cluster-RCTs in neonates (term or preterm) undergoing painful procedures comparing NSAIDs and NMDA receptor antagonists to placebo or no drug, non-pharmacological intervention, other analgesics, or different routes of administration.  DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods. Our main outcomes were pain assessed during the procedure and up to 10 minutes after the procedure with a validated scale; episodes of bradycardia; episodes of apnea; and hypotension requiring medical therapy.

MAIN RESULTS

We included two RCTs involving a total of 269 neonates conducted in Nigeria and India.  NMDA receptor antagonists versus no treatment, placebo, oral sweet solution, or non-pharmacological intervention One RCT evaluated using oral ketamine (10 mg/kg body weight) versus sugar syrup (66.7% w/w at 1 mL/kg body weight) for neonatal circumcision.  The evidence is very uncertain about the effect of ketamine on pain score during the procedure, assessed with the Neonatal Infant Pain Scale (NIPS), compared with placebo (mean difference (MD) -0.95, 95% confidence interval (CI) -1.32 to -0.58; 1 RCT; 145 participants; very low-certainty evidence). No other outcomes of interest were reported on. Head-to-head comparison of different analgesics One RCT evaluated using intravenous fentanyl versus intravenous ketamine during laser photocoagulation for retinopathy of prematurity. Neonates receiving ketamine followed an initial regimen (0.5 mg/kg bolus 1 minute before procedure) or a revised regimen (additional intermittent bolus doses of 0.5 mg/kg every 10 minutes up to a maximum of 2 mg/kg), while those receiving fentanyl followed either an initial regimen (2 μg/kg over 5 minutes, 15 minutes before the procedure, followed by 1 μg/kg/hour as a continuous infusion) or a revised regimen (titration of 0.5 μg/kg/hour every 15 minutes to a maximum of 3 μg/kg/hour). The evidence is very uncertain about the effect of ketamine compared with fentanyl on pain score assessed with the Premature Infant Pain Profile-Revised (PIPP-R) scores during the procedure (MD 0.98, 95% CI 0.75 to 1.20; 1 RCT; 124 participants; very low-certainty evidence); on episodes of apnea occurring during the procedure (risk ratio (RR) 0.31, 95% CI 0.08 to 1.18; risk difference (RD) -0.09, 95% CI -0.19 to 0.00; 1 study; 124 infants; very low-certainty evidence); and on hypotension requiring medical therapy occurring during the procedure (RR 5.53, 95% CI 0.27 to 112.30; RD 0.03, 95% CI -0.03 to 0.10; 1 study; 124 infants; very low-certainty evidence). The included study did not report pain score assessed up to 10 minutes after the procedure or episodes of bradycardia occurring during the procedure. We did not identify any studies comparing NSAIDs versus no treatment, placebo, oral sweet solution, or non-pharmacological intervention or different routes of administration of the same analgesics. We identified three studies awaiting classification.  AUTHORS' CONCLUSIONS: The two small included studies comparing ketamine versus either placebo or fentanyl, with very low-certainty evidence, rendered us unable to draw meaningful conclusions. The evidence is very uncertain about the effect of ketamine on pain score during the procedure compared with placebo or fentanyl. We found no evidence on NSAIDs or studies comparing different routes of administration. Future research should prioritize large studies evaluating non-opioid analgesics in this population. As the studies included in this review suggest potential positive effects of ketamine administration, studies evaluating ketamine are of interest. Furthermore, as we identified no studies on NSAIDs, which are widely used in older infants, or comparing different routes of administration, such studies should be a priority going forward.

Paracetamol (acetaminophen) for patent ductus arteriosus in preterm or low birth weight infants

BACKGROUND

The different management strategies for patent ductus arteriosus (PDA) in preterm infants are expectant management, surgery, or medical treatment with non-selective cyclo-oxygenase inhibitors. Randomized controlled trials (RCTs) have suggested that paracetamol may be an effective and safe agent for the closure of a PDA.

OBJECTIVES

To determine the efficacy and safety of paracetamol as monotherapy or as part of combination therapy via any route of administration, compared with placebo, no intervention, or another prostaglandin inhibitor, for prophylaxis or treatment of an echocardiographically-diagnosed PDA in preterm or low birth weight infants.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, and three trials registers on 13 October 2021, and one other database on 1 March 2022. We also checked references and contacted study authors to identify additional studies.

SELECTION CRITERIA

We included RCTs and quasi-RCTs in which paracetamol (single-agent or combination therapy) was compared to no intervention, placebo, or other agents used for closure of PDA, irrespective of dose, duration, and mode of administration in preterm infants. Two independent authors reviewed the search results and made a final selection of potentially eligible articles through discussion.

DATA COLLECTION AND ANALYSIS

We performed data collection and analyses in accordance with the methods of Cochrane Neonatal. We used the GRADE approach to assess the certainty of evidence for the following outcomes: failure of ductal closure after the first course of treatment; all-cause mortality during initial hospital stay; and necrotizing enterocolitis (NEC).

MAIN RESULTS

For this update, we included 27 studies enrolling 2278 infants. We considered the overall risk of bias in the 27 studies to vary from low to unclear. We identified 24 ongoing studies. Paracetamol versus ibuprofen  There was probably little to no difference between paracetamol and ibuprofen for failure of ductal closure after the first course (risk ratio (RR) 1.02, 95% confidence interval (CI) 0.88 to 1.18; 18 studies, 1535 infants; moderate-certainty evidence). There was likely little to no difference between paracetamol and ibuprofen for all-cause mortality during hospital stay (RR 1.09, 95% CI 0.80 to 1.48; 8 studies, 734 infants; moderate-certainty evidence), and for NEC (RR 1.30, 95% CI 0.87 to 1.94; 10 studies, 1015 infants; moderate-certainty evidence). Paracetamol versus indomethacin There was little to no difference between paracetamol and indomethacin for failure of ductal closure after the first course (RR 1.02, 95% CI 0.78 to 1.33; 4 studies, 380 infants; low-certainty evidence). There was little to no difference between paracetamol and indomethacin for all-cause mortality during hospital stay (RR 0.86, 95% CI 0.39 to 1.92; 2 studies, 114 infants; low-certainty evidence). The rate of NEC may be lower in the paracetamol group (3.7%) versus the indomethacin group(9.2%) (RR 0.42, 95% CI 0.19 to 0.96; 4 studies, 384 infants; low-certainty evidence).  Prophylactic paracetamol versus placebo/no intervention Prophylactic paracetamol (17%) compared to placebo/no intervention (61%) may reduce failure of ductal closure after one course (RR 0.27, 95% CI 0.18 to 0.42; 3 studies, 240 infants; low-certainty evidence). There was little to no difference between prophylactic paracetamol and placebo/no intervention for all-cause mortality during hospital stay (RR 0.59, 95% CI 0.24 to 1.44; 3 studies, 240 infants; low-certainty evidence). No studies reported on NEC.  Early paracetamol treatment versus placebo/no intervention Early paracetamol treatment (28%) compared to placebo/no intervention (79%) may reduce failure of ductal closure after one course when used before 14 days' postnatal age (RR 0.35, 95% CI 0.23 to 0.53; 2 studies, 127 infants; low-certainty evidence). No studies reported on all-cause mortality during hospital stay or NEC.  Late paracetamol treatment versus placebo/no intervention  There was little to no difference between late paracetamol and placebo for failure of ductal closure after one course of treatment when used at or after 14 days' postnatal age (RR 0.85, 95% CI 0.72 to 1.01; 1 study, 55 infants; low-certainty evidence) or NEC (RR 1.04, 95% CI 0.07 to 15.76; 1 study, 55 infants; low-certainty evidence). No data were reported for all-cause mortality during hospital stay.  Paracetamol combined with ibuprofen versus ibuprofen combined with placebo or no intervention There was little to no difference between paracetamol plus ibuprofen compared to ibuprofen plus placebo or no intervention for failure of ductal closure after the first course (RR 0.77, 95% CI 0.43 to 1.36; 2 studies, 111 infants; low-certainty evidence). There was little to no difference between paracetamol plus ibuprofen compared to ibuprofen plus placebo or no intervention for NEC (RR 0.33, 95% CI 0.01 to 7.45; 1 study, 24 infants; low-certainty evidence). No data were reported for all-cause mortality during hospital stay.  AUTHORS' CONCLUSIONS: Moderate-certainty evidence suggests that there is probably little or no difference in effectiveness between paracetamol and ibuprofen; low-certainty evidence suggests that there is probably little or no difference in effectiveness between paracetamol and indomethacin; low-certainty evidence suggests that prophylactic paracetamol may be more effective than placebo/no intervention; low-certainty evidence suggests that early paracetamol treatment may be more effective than placebo/no intervention; low-certainty evidence suggests that there is probably little or no difference between late paracetamol treatment and placebo, and probably little or no difference in effectiveness between the combination of paracetamol plus ibuprofen versus ibuprofen alone for the closure of PDA after the first course of treatment. The majority of neonates included in these studies were of moderate preterm gestation. Thus, establishing the efficacy and safety of paracetamol for PDA treatment in extremely low birth weight (ELBW: birth weight < 1000 grams) and extremely low gestational age neonates (ELGANs < 28 weeks' gestation) requires further studies.

Patent Ductus Arteriosus: A Contemporary Perspective for the Pediatric and Adult Cardiac Care Provider

The burden of patent ductus arteriosus (PDA) continues to be significant. In view of marked differences in preterm infants versus more mature, term counterparts (viewed on a continuum with adolescent and adult patients), mechanisms regulating ductal patency, genetic contributions, clinical consequences, and diagnostic and treatment thresholds are discussed separately, when appropriate. Among both preterm infants and older children and adults, a range of hemodynamic profiles highlighting the markedly variable consequences of the PDA are provided. In most contemporary settings, transcatheter closure is preferable over surgical ligation, but data on longer-term outcomes, particularly among preterm infants, are lacking. The present review provides recommendations to identify gaps in PDA diagnosis, management, and treatment on which subsequent research can be developed. Ultimately, the combination of refined diagnostic thresholds and expanded treatment options provides the best opportunities to address the burden of PDA. Although fundamental gaps remain unanswered, the present review provides pediatric and adult cardiac care providers with a contemporary framework in PDA care to support the practice of evidence-based medicine.

Alteration of the Oligodendrocyte Lineage Varies According to the Systemic Inflammatory Stimulus in Animal Models That Mimic the Encephalopathy of Prematurity

Preterm birth before the gestational age of 32 weeks is associated with the occurrence of specific white matter damage (WMD) that can compromise the neurological outcome. These white matter abnormalities are embedded in more global brain damage defining the encephalopathy of prematurity (EoP). A global reduction in white matter volume that corresponds to chronic diffuse WMD is the most frequent form in contemporary cohorts of very preterm infants. This WMD partly results from alterations of the oligodendrocyte (OL) lineage during the vulnerability window preceding the beginning of brain myelination. The occurrence of prenatal, perinatal and postnatal events in addition to preterm birth is related to the intensity of WMD. Systemic inflammation is widely recognised as a risk factor of WMD in humans and in animal models. This review reports the OL lineage alterations associated with the WMD observed in infants suffering from EoP and emphasizes the role of systemic inflammation in inducing these alterations. This issue is addressed through data on human tissue and imaging, and through neonatal animal models that use systemic inflammation to induce WMD. Interestingly, the OL lineage damage varies according to the inflammatory stimulus, i.e., the liposaccharide portion of the E.Coli membrane (LPS) or the proinflammatory cytokine Interleukin-1β (IL-1β). This discrepancy reveals multiple cellular pathways inducible by inflammation that result in EoP. Variable long-term consequences on the white matter morphology and functioning may be speculated upon according to the intensity of the inflammatory challenge. This hypothesis emerges from this review and requires further exploration.

A Novel Patent Ductus Arteriosus Severity Score to Predict Clinical Outcomes in Premature Neonates

Background: Patent Ductus Arteriosus (PDA) in premature neonates has been associated with comorbidities including chronic lung disease (CLD), and death. However, the treatment of PDA remains controversial. There have been several echocardiographic variables previously used to determine the hemodynamic significance of PDA but their utility in early prediction of clinical outcomes is not well studied. Objective: The objective of our study was to evaluate the use of a severity scoring system incorporating markers of systemic under perfusion, pulmonary over perfusion and left ventricular (LV) function in predicting clinical outcomes in premature neonates. Methods: It is a single center prospective observational study involving newborns < 32 weeks’ gestation. An echocardiogram was done within seven days of life to measure variables previously known to predict severity of shunting in PDA including pulmonary perfusion index (PPI). Predictors of CLD/death were identified using multivariate logistic regression. A severity score was derived and its ability to predict clinical outcomes was tested using a receiver operating characteristic curve. Results: We studied 98 infants with a mean (SD) gestation of 28.9 ± 1.91 weeks and birth weight of 1228.06 ± 318.94 g, respectively. We identified five echocardiographic variables along with gestational age that was independently associated with the outcome variable (PPI, LV output, Superior Mesenteric Artery [SMA] Velocity Time Integral [VTI], Peak diastolic flow velocity in Pulmonary Vein [PV Vd], and reversal of flow in diastole in descending aorta [DFR]). The range of severity score was 0 (low risk) to 12 (high risk). A higher score was associated with the primary outcome variable of CLD/death (7.5 [1.2] vs. 3.6 [1.5], p < 0.001). Our severity score had an area under the curve of 0.97 (95% CI 0.93−0.99, p < 0.001) for predicting CLD/death. Conclusion: Our new PDA severity score of 5.5 has a sensitivity and specificity of 94% and 93%, and positive and negative predictive values of 94% and 93%, respectively.

Prophylactic cyclo-oxygenase inhibitor drugs for the prevention of morbidity and mortality in preterm infants: a network meta-analysis

BACKGROUND

Patent ductus arteriosus (PDA) is associated with significant morbidity and mortality in preterm infants. Cyclooxygenase inhibitors (COX-I) may prevent PDA-related complications. Controversy exists on which COX-I drug is the most effective and has the best safety profile in preterm infants.

OBJECTIVES

To compare the effectiveness and safety of prophylactic COX-I drugs and 'no COXI prophylaxis' in preterm infants using a Bayesian network meta-analysis (NMA).

SEARCH METHODS

Searches of Cochrane CENTRAL via Wiley, OVID MEDLINE and Embase via Elsevier were conducted on 9 December 2021. We conducted independent searches of clinical trial registries and conference abstracts; and scanned the reference lists of included trials and related systematic reviews.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that enrolled preterm or low birth weight infants within the first 72 hours of birth without a prior clinical or echocardiographic diagnosis of PDA and compared prophylactic administration of indomethacin or ibuprofen or acetaminophen versus each other, placebo or no treatment.

DATA COLLECTION AND ANALYSIS

We used the standard methods of Cochrane Neonatal. We used the GRADE NMA approach to assess the certainty of evidence derived from the NMA for the following outcomes: severe intraventricular haemorrhage (IVH), mortality, surgical or interventional PDA closure, necrotizing enterocolitis (NEC), gastrointestinal perforation, chronic lung disease (CLD) and cerebral palsy (CP).

MAIN RESULTS

We included 28 RCTs (3999 preterm infants). Nineteen RCTs (n = 2877) compared prophylactic indomethacin versus placebo/no treatment, 7 RCTs (n = 914) compared prophylactic ibuprofen versus placebo/no treatment and 2 RCTs (n = 208) compared prophylactic acetaminophen versus placebo/no treatment. Nine RCTs were judged to have high risk of bias in one or more domains.We identified two ongoing trials on prophylactic acetaminophen. Bayesian random-effects NMA demonstrated that prophylactic indomethacin probably led to a small reduction in severe IVH (network RR 0.66, 95% Credible Intervals [CrI] 0.49 to 0.87; absolute risk difference [ARD] 43 fewer [95% CrI, 65 fewer to 16 fewer] per 1000; median rank 2, 95% CrI 1-3; moderate-certainty), a moderate reduction in mortality (network RR 0.85, 95% CrI 0.64 to 1.1; ARD 24 fewer [95% CrI, 58 fewer to 16 more] per 1000; median rank 2, 95% CrI 1-4; moderate-certainty) and surgical PDA closure (network RR 0.40, 95% CrI 0.14 to 0.66; ARD 52 fewer [95% CrI, 75 fewer to 30 fewer] per 1000; median rank 2, 95% CrI 1-2; moderate-certainty) compared to placebo. Prophylactic indomethacin resulted in trivial difference in NEC (network RR 0.76, 95% CrI 0.35 to 1.2; ARD 16 fewer [95% CrI, 42 fewer to 13 more] per 1000; median rank 2, 95% CrI 1-3; high-certainty), gastrointestinal perforation (network RR 0.92, 95% CrI 0.11 to 3.9; ARD 4 fewer [95% CrI, 42 fewer to 137 more] per 1000; median rank 1, 95% CrI 1-3; moderate-certainty) or CP (network RR 0.97, 95% CrI 0.44 to 2.1; ARD 3 fewer [95% CrI, 62 fewer to 121 more] per 1000; median rank 2, 95% CrI 1-3; low-certainty) and may result in a small increase in CLD (network RR 1.10, 95% CrI 0.93 to 1.3; ARD 36 more [95% CrI, 25 fewer to 108 more] per 1000; median rank 3, 95% CrI 1-3; low-certainty). Prophylactic ibuprofen probably led to a small reduction in severe IVH (network RR 0.69, 95% CrI 0.41 to 1.14; ARD 39 fewer [95% CrI, 75 fewer to 18 more] per 1000; median rank 2, 95% CrI 1-4; moderate-certainty) and moderate reduction in surgical PDA closure (network RR 0.24, 95% CrI 0.06 to 0.64; ARD 66 fewer [95% CrI, from 82 fewer to 31 fewer] per 1000; median rank 1, 95% CrI 1-2; moderate-certainty) compared to placebo. Prophylactic ibuprofen may result in moderate reduction in mortality (network RR 0.83, 95% CrI 0.57 to 1.2; ARD 27 fewer [95% CrI, from 69 fewer to 32 more] per 1000; median rank 2, 95% CrI 1-4; low-certainty) and leads to trivial difference in NEC (network RR 0.73, 95% CrI 0.31 to 1.4; ARD 18 fewer [95% CrI, from 45 fewer to 26 more] per 1000; median rank 1, 95% CrI 1-3; high-certainty), or CLD (network RR 1.00, 95% CrI 0.83 to 1.3; ARD 0 fewer [95% CrI, from 61 fewer to 108 more] per 1000; median rank 2, 95% CrI 1-3; low-certainty). The evidence is very uncertain on effect of ibuprofen on gastrointestinal perforation (network RR 2.6, 95% CrI 0.42 to 20.0; ARD 76 more [95% CrI, from 27 fewer to 897 more] per 1000; median rank 3, 95% CrI 1-3; very low-certainty). The evidence is very uncertain on the effect of prophylactic acetaminophen on severe IVH (network RR 1.17, 95% CrI 0.04 to 55.2; ARD 22 more [95% CrI, from 122 fewer to 1000 more] per 1000; median rank 4, 95% CrI 1-4; very low-certainty), mortality (network RR 0.49, 95% CrI 0.16 to 1.4; ARD 82 fewer [95% CrI, from 135 fewer to 64 more] per 1000; median rank 1, 95% CrI 1-4; very low-certainty), or CP (network RR 0.36, 95% CrI 0.01 to 6.3; ARD 70 fewer [95% CrI, from 109 fewer to 583 more] per 1000; median rank 1, 95% CrI 1-3; very low-certainty). In summary, based on ranking statistics, both indomethacin and ibuprofen were equally effective (median ranks 2 respectively) in reducing severe IVH and mortality. Ibuprofen (median rank 1) was more effective than indomethacin in reducing surgical PDA ligation (median rank 2). However, no statistically-significant differences were observed between the COX-I drugs for any of the relevant outcomes.

AUTHORS' CONCLUSIONS

Prophylactic indomethacin probably results in a small reduction in severe IVH and moderate reduction in mortality and surgical PDA closure (moderate-certainty), may result in a small increase in CLD (low-certainty) and results in trivial differences in NEC (high-certainty), gastrointestinal perforation (moderate-certainty) and cerebral palsy (low-certainty). Prophylactic ibuprofen probably results in a small reduction in severe IVH and moderate reduction in surgical PDA closure (moderate-certainty), may result in a moderate reduction in mortality (low-certainty) and trivial differences in CLD (low-certainty) and NEC (high-certainty). The evidence is very uncertain about the effect of acetaminophen on any of the clinically-relevant outcomes.

Recent research on the effect of common treatments given in the perinatal period on neurodevelopment in offspring

The perinatal period is the key period for the development of brain and central nervous system, and different events in this period will have a profound influence on brain development. Glucocorticoids, antibiotics, magnesium sulfate, caffeine, pulmonary surfactant, and mild hypothermia treatment are commonly used drugs or treatment methods in the perinatal period and are closely associated with the prognosis of neonatal neurodevelopment. This article reviews the latest research on the effect of perinatal treatments on neonatal neurodevelopment, so as to provide a reference for clinical decision making.

Nephrotoxic medications and associated acute kidney injury in hospitalized neonates

OBJECTIVES

Hospitalized neonates are often treated with nephrotoxic medications, a known risk factor for acute kidney injury (AKI). Nephrotoxic medications and AKI, especially in periviable neonates, could be detrimental to nephrogenesis. Our objectives were to evaluate the prevalence of neonatal treatment with nephrotoxic medications and its relationship with AKI in in the first 28 days of life, and to delineate the associated demographics and diagnoses.

STUDY DESIGN

Multicenter retrospective analysis using the national Pediatric Hospital Information System database, including 49 pediatric hospitals. Neonates admitted within the first two postnatal days were included. Treatment with 37 nephrotoxic medications across demographics and clinical variables, and relationship with AKI were evaluated. AKI was determined by using the International Classification of Diseases codes.

RESULTS

Of 192,229 neonates, 74% were treated with at least one nephrotoxic medication. Incidence of AKI was significantly higher in the treated group (aRR 3.68 [95% CI: 2.85, 4.75]). The aRRs of treatment were increased in infants born < 32-week, and < 2000 g. Nephrotoxic medications were prescribed to 90-95% of  neonates born ≤ 28-week gestational age. Most treatments (95-98%) occurred in the first 3 days. Intravascular aminoglycosides were the most frequent type; 28% of neonates were treated for ≥ 4 calendar days. Most common diagnoses were infections (25%) and patent ductus arteriosus (20%).

CONCLUSIONS

Neonatal treatment with nephrotoxic medications is common, especially among the smallest, most immature preterm neonates and demonstrates a need for initiatives to reduce neonatal exposure to these agents, when feasible. Across all gestational age categories, the prevalence of AKI is higher in the neonates treated with nephrotoxic drugs. The long-term effects of treatment with nephrotoxic medications and subsequent AKI on nephrogenesis and nephron endowment will need to be evaluated.

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.

Value of near-infrared spectroscopy in monitoring intestinal tissue oxygen saturation in preterm infants with hemodynamically significant patent ductus arteriosus: a prospective research

OBJECTIVES

To study the change in regional oxygen saturation (rSO2) of intestinal tissue in preterm infants with hemodynamically significant patent ductus arteriosus (hsPDA) by near-infrared spectroscopy, and the clinical significance of the change in intestinal oxygen level in preterm infants with hsPDA.

METHODS

The preterm infants with patent ductus arteriosus (PDA) who had gestational age <32 weeks and/or birth weight <1 500 g were prospectively enrolled, who were admitted to the Department of Neonatology, Shenzhen Longgang Central Hospital from October 2017 to October 2020.According to the diagnostic criteria for hsPDA, the preterm infants with patent ductus arteriosus (PDA) were divided into two groups: hsPDA and non-hsPDA. According to closure of the ductus arteriosus after oral administration of ibuprofen, the preterm infants in the hsPDA group were subdivided into two groups: hsPDA closure and hsPDA non-closure. Hemodynamic parameters were measured at diagnosis of PDA and after treatment, and the level of intestinal tissue rSO2 was monitored continuously to analyze its change.

RESULTS

A total of 241 preterm infants with PDA were enrolled, with 55 infants (22.8%) in the hsPDA group and 186 infants (77.2%) in the non-hsPDA group. There were 36 infants (65%) in the hsPDA closure group and 19 infants (35%) in the hsPDA non-closure group. Compared with the non-hsPDA group, the hsPDA group had a significantly higher left atrial diameter/aortic root diameter ratio and significantly lower left ventricular ejection fraction and fractional shortening (P<0.05). At each time point within 6 hours after diagnosis (1, 2, 4, and 6 hours), the hsPDA group had significantly lower intestinal tissue rSO2 than the non-hsPDA group (P<0.05), and intestinal tissue rSO2 gradually decreased over time in the hsPDA group (P<0.05), with the lowest level of 0.448±0.014 at 6 hours. Compared with the hsPDA non-closure group, the hsPDA closure group had a significantly lower left atrial diameter/aortic root diameter ratio and significantly higher left ventricular ejection fraction and fractional shortening (P<0.05). At each time point within 48-96 hours after treatment (48, 72, and 96 hours), the hsPDA closure group had significantly higher intestinal tissue rSO2 than the hsPDA non-closure group (P<0.05), and intestinal tissue rSO2 gradually increased since 24 hours after treatment in the hsPDA closure group (P<0.05), with the highest level of 0.578±0.031 at 96 hours.

CONCLUSIONS

hsPDA has an impact on intestinal tissue oxygenation in preterm infants, and continuous monitoring of intestinal tissue rSO2 by near-infrared spectroscopy can help to guide the clinical management of hsPDA in preterm infants.

An Update on the Prevention and Management of Bronchopulmonary Dysplasia

Bronchopulmonary dysplasia (BPD) is a common morbidity affecting preterm infants and is associated with substantial long-term disabilities. There has been no change in the incidence of BPD over the past 20 years, despite improvements in survival and other outcomes. The preterm lung is vulnerable to injuries occurring as a result of invasive ventilation, hyperoxia, and infections that contribute to the development of BPD. Clinicians caring for infants in the neonatal intensive care unit use multiple therapies for the prevention and management of BPD. Non-invasive ventilation strategies and surfactant administration via thin catheters are treatment approaches that aim to avoid volutrauma and barotrauma to the preterm developing lung. Identifying high-risk infants to receive postnatal corticosteroids and undergo patent ductus arteriosus closure may help to individualize care and promote improved lung outcomes. In infants with established BPD, outpatient management is complex and requires coordination from several specialists and therapists. However, most current therapies used to prevent and manage BPD lack solid evidence to support their effectiveness. Further research is needed with appropriately defined outcomes to develop effective therapies and impact the incidence of BPD.

Temporal Trends of Acute Kidney Injury and Associated Risk Exposures in Extremely Preterm Infants

BACKGROUND AND OBJECTIVES

Neonatal AKI in the preterm population is an under-recognized morbidity. Detecting AKI in preterm infants is important for their long-term kidney health. We aimed to examine the yearly trends of incidence and the related morbidities and care practices affecting the occurrence of neonatal AKI in extremely preterm (gestational age <29 weeks) and very preterm (gestational age 29-32 weeks) infants.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

The trends and the related risk factors and care practices of AKI were examined in the extremely preterm (n=434) and very preterm (n=257) infants who were admitted within 14 days after birth from 2005 to 2018 to the University Hospital and had at least two serum creatinine measurements during hospitalization. We defined AKI as a serum creatinine rise of 0.3 mg/dl or more within 48 hours or a 1.5-fold increase within 7 days.

RESULTS

The extremely preterm group had a three-fold higher incidence of AKI (30% versus 10%) than the very preterm group. Among preterm infants with AKI, 92% had one episode of AKI, and 45% experienced stage 2 or 3 AKI; the mean duration of AKI was 12±9 days. Across the 14-year period, the crude incidence of AKI declined markedly from 56% to 17% in the extremely preterm group and from 23% to 6% in the very preterm group. After adjustment, a significant decline of AKI incidence was still observed in the extremely preterm group. The declining AKI in the extremely preterm infants was related to the trends of decreasing incidences of neonatal transfer, prolonged aminoglycoside exposure, prophylactic use of nonsteroidal anti-inflammatory drugs, and sepsis.

CONCLUSIONS

We observed a declining trend in the incidence of neonatal AKI among extremely preterm infants from 2005 to 2018, which may be related to improvement of care practices.

Evidence for the Management of Bronchopulmonary Dysplasia in Very Preterm Infants

BACKGROUND

Very preterm birth often results in the development of bronchopulmonary dysplasia (BPD) with an inverse correlation of gestational age and birthweight. This very preterm population is especially exposed to interventions, which affect the development of BPD.

OBJECTIVE

The goal of our review is to summarize the evidence on these daily procedures and provide evidence-based recommendations for the management of BPD.

METHODS

We conducted a systematic literature research using MEDLINE/PubMed on antenatal corticosteroids, surfactant-replacement therapy, caffeine, ventilation strategies, postnatal corticosteroids, inhaled nitric oxide, inhaled bronchodilators, macrolides, patent ductus arteriosus, fluid management, vitamin A, treatment of pulmonary hypertension and stem cell therapy.

RESULTS

Evidence provided by meta-analyses, systematic reviews, randomized controlled trials (RCTs) and large observational studies are summarized as a narrative review.

DISCUSSION

There is strong evidence for the use of antenatal corticosteroids, surfactant-replacement therapy, especially in combination with noninvasive ventilation strategies, caffeine and lung-protective ventilation strategies. A more differentiated approach has to be applied to corticosteroid treatment, the management of patent ductus arteriosus (PDA), fluid-intake and vitamin A supplementation, as well as the treatment of BPD-associated pulmonary hypertension. There is no evidence for the routine use of inhaled bronchodilators and prophylactic inhaled nitric oxide. Stem cell therapy is promising, but should be used in RCTs only.

Morbidity associated with patent ductus arteriosus in preterm newborns: a retrospective case-control study

INTRODUCTION

Association between persistency of a patent ductus arteriosus (PDA) and morbidity in preterm newborns is still controversial. We aimed to investigate the relation between PDA and morbidity in a large retrospective study.

METHODS

A case-control study including neonates consecutively admitted to the Neonatal Intensive Care Unit (NICU), with gestational age (GA) < 32 weeks or body birth weight (BW) < 1500 g, over a 5-year period. Newborns were divided into Cases and Controls, according with the presence or absence of a hemodynamically significant PDA (hs-PDA).

RESULTS

We enrolled 85 Cases and 193 Controls. Subjects with hs-PDA had significantly (p < 0.001) lower GA (26.7 w, 95%CI 27.1-28.0 vs. 30.1 w, 95%CI 29.7-30.4), BW (1024 g, 95% CI 952-1097 vs. 1310 g 95%CI 1263-1358) and an increased morbidity (60.0% vs. 18.7%). In a sub-group of extremely preterm newborns (GA ≤ 28 weeks and BW ≤ 1000 g), the rate of bronchopulmonary dysplasia (BPD) was significantly increased in Cases (31.7%) compared with Controls (5.9%, p = 0.033). Multivariate analysis showed that morbidity significantly depended on hs-PDA, GA and BW, and that, in extremely preterms, the hs-PDA represented an independent risk factor for BPD.

CONCLUSIONS

Occurrence of the main morbidities of prematurity depended by hs-PDA, in association with GA, BW, and use of prenatal steroids. In extremely premature babies, hs-PDA is a risk factor for BPD, one of the most important morbidity of prematurity, independently by other confounding variables.

Patent Ductus Arteriosus of the Preterm Infant

Postnatal ductal closure is stimulated by rising oxygen tension and withdrawal of vasodilatory mediators (prostaglandins, nitric oxide, adenosine) and by vasoconstrictors (endothelin-1, catecholamines, contractile prostanoids), ion channels, calcium flux, platelets, morphologic maturity, and a favorable genetic predisposition. A persistently patent ductus arteriosus (PDA) in preterm infants can have clinical consequences. Decreasing pulmonary vascular resistance, especially in extremely low gestational age newborns, increases left-to-right shunting through the ductus and increases pulmonary blood flow further, leading to interstitial pulmonary edema and volume load to the left heart. Potential consequences of left-to-right shunting via a hemodynamically significant patent ductus arteriosus (hsPDA) include increased risk for prolonged ventilation, bronchopulmonary dysplasia, necrotizing enterocolitis or focal intestinal perforation, intraventricular hemorrhage, and death. In the last decade, there has been a trend toward less aggressive treatment of PDA in preterm infants. However, there is a subgroup of infants who will likely benefit from intervention, be it pharmacologic, interventional, or surgical: (1) prophylactic intravenous indomethacin in highly selected extremely low gestational age newborns with PDA (<26 + 0/7 weeks' gestation, <750 g birth weight), (2) early targeted therapy of PDA in selected preterm infants at particular high risk for PDA-associated complications, and (3) PDA ligation, catheter intervention, or oral paracetamol may be considered as rescue options for hsPDA closure. The impact of catheter-based closure of hsPDA on clinical outcomes should be determined in future prospective studies. Finally, we provide a novel treatment algorithm for PDA in preterm infants that integrates the several treatment modalities in a staged approach.

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

The optimal management strategy for patent ductus arteriosus in preterm infants remains a topic of debate. Available evidence for a treatment strategy might be biased by the delayed spontaneous closure of the ductus arteriosus in preterm infants, which appears to depend on patient characteristics. We performed a systematic review of all literature on PDA studies to collect patient characteristics and reported numbers of patients with a ductus arteriosus and spontaneous closure. Spontaneous closure rates showed a high variability but were lowest in studies that only included preterm infants with gestational ages below 28 weeks or birth weights below 1,000 g (34% on day 4; 41% on day 7) compared to studies that also included infants with higher gestational ages or higher birth weights (up to 55% on day 3 and 78% on day 7). The probability of spontaneous closure of the ductus arteriosus keeps increasing until at least 1 week after birth which favors delayed treatment of only those infants that do not show spontaneous closure. Better prediction of the spontaneous closure of the ductus arteriosus in the individual newborn is a key factor to find the optimal management strategy for PDA in preterm infants.