Indomethacin for symptomatic patent ductus arteriosus in preterm infants

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

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

Platelet Count and Volume and Pharmacological Closure with Paracetamol of Ductus Arteriosus in Preterm Infants

Background: Low platelet count might promote resistance to pharmacological closure with indomethacin and ibuprofen of a hemodynamically significant patent ductus arteriosus (hsPDA). However, no studies have investigated if this occurs with paracetamol. Methods: We retrospectively assessed the correlation between platelet count, mean platelet volume (MPV), and plateletcrit (PCT), as well as the effectiveness of paracetamol in closing hsPDA in infants born at 23⁺⁰–31⁺⁶ weeks of gestation who were treated with 15 mg/kg/6 h of i.v. paracetamol for 3 days. Results: We studied 79 infants: 37 (47%) Had closure after a course of paracetamol and 42 (53%) did not. Platelet count and PCT did not correlate with paracetamol success or failure in closing hsPDA, while MPV was lower at birth (10.7 ± 1.4 vs. 9.5 ± 1.1; p < 0.001) and prior to starting therapy (11.7 ± 1.9 vs. 11.0 ± 1.6; p = 0.079) in refractory infants. Regression analysis confirmed that the low MVP measured prior to starting the treatment increased the risk of hsPDA paracetamol closure failure (OR 1.664, 95% CI 1.153–2.401). Conclusions: The greater MPV correlated positively with the effectiveness of paracetamol in closing hsPDA, while platelet count and PCT did not influence closure rates. Additional studies are needed to confirm our results.

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.

Indomethacin for symptomatic patent ductus arteriosus in preterm infants

BACKGROUND

Symptomatic patent ductus arteriosus (PDA) is associated with mortality and morbidity in preterm infants. In these infants, prophylactic use of indomethacin, a non-selective cyclooxygenase inhibitor, has demonstrated short-term clinical benefits. The effect of indomethacin in preterm infants with a symptomatic PDA remains unexplored.

OBJECTIVES

To determine the effectiveness and safety of indomethacin (given by any route) compared to placebo or no treatment in reducing mortality and morbidity in preterm infants with a symptomatic PDA.

SEARCH METHODS

We used the standard search strategy of Cochrane Neonatal to search Cochrane Central Register of Controlled Trials (CENTRAL; 2020, Issue 7), in the Cochrane Library; Ovid MEDLINE(R) and Epub Ahead of Print, In-Process & Other Non-Indexed Citations, Daily and Versions(R); and Cumulative Index to Nursing and Allied Health Literature (CINAHL), on 31 July 2020. We also searched clinical trials databases and the reference lists of retrieved articles for randomized controlled trials (RCTs) and quasi-RCTs.

SELECTION CRITERIA

We included RCTs and quasi-RCTs that compared indomethacin (any dose, any route) versus placebo or no treatment in preterm infants.

DATA COLLECTION AND ANALYSIS

We used the standard methods of Cochrane Neonatal, with separate evaluation of trial quality and data extraction by at least two review authors. We used the GRADE approach to assess the certainty of evidence for the following outcomes: failure of PDA closure within one week of administration of the first dose of indomethacin; bronchopulmonary dysplasia (BPD) at 28 days' postnatal age and at 36 weeks' postmenstrual age; proportion of infants requiring surgical ligation or transcatheter occlusion; all-cause neonatal mortality; necrotizing enterocolitis (NEC) (≥ Bell stage 2); and mucocutaneous or gastrointestinal bleeding.

MAIN RESULTS

We included 14 RCTs (880 preterm infants). Four out of the 14 included studies were judged to have high risk of bias in one or more domains. Indomethacin administration was associated with a large reduction in failure of PDA closure within one week of administration of the first dose (risk ratio (RR) 0.30, 95% confidence interval (CI) 0.23 to 0.38; risk difference (RD) -0.52, 95% CI -0.58 to -0.45; 10 studies, 654 infants; high-certainty evidence). There may be little to no difference in the incidence of BPD (BPD defined as supplemental oxygen need at 28 days' postnatal age: RR 1.45, 95% CI 0.60 to 3.51; 1 study, 55 infants; low-certainty evidence; BPD defined as supplemental oxygen need at 36 weeks' postmenstrual age: RR 0.80, 95% CI 0.41 to 1.55; 1 study, 92 infants; low-certainty evidence) and probably little to no difference in mortality (RR 0.78, 95% CI 0.46 to 1.33; 8 studies, 314 infants; moderate-certainty evidence) with use of indomethacin for symptomatic PDA. No differences were demonstrated in the need for surgical PDA ligation (RR 0.66, 95% CI 0.33 to 1.29; 7 studies, 275 infants; moderate-certainty evidence), in NEC (RR 1.27, 95% CI 0.36 to 4.55; 2 studies, 147 infants; low-certainty evidence), or in mucocutaneous or gastrointestinal bleeding (RR 0.33, 95% CI 0.01 to 7.58; 2 studies, 119 infants; low-certainty evidence) with use of indomethacin compared to placebo or no treatment. Certainty of evidence for BPD, surgical PDA ligation, NEC, and mucocutaneous or gastrointestinal bleeding was downgraded for very serious or serious imprecision.

AUTHORS' CONCLUSIONS

High-certainty evidence shows that indomethacin is effective in closing a symptomatic PDA compared to placebo or no treatment in preterm infants. Evidence is insufficient regarding effects of indomethacin on other clinically relevant outcomes and medication-related adverse effects.