Follow-up study of the early, randomised paracetamol trial to preterm infants, found no adverse reactions at the two-years corrected age

Neurodevelopmental outcomes following paracetamol use for treatment of patent ductus arteriosus: A review

AIM

Concerns exist regarding potential adverse neurodevelopmental outcomes associated with paracetamol exposure during pregnancy and early infancy. This review evaluates the evidence for the impact of paracetamol use for patent ductus arteriosus (PDA) treatment on neurodevelopmental outcomes in preterm infants.

METHODS

A literature search was performed via Medline, Ovid Embase and Cumulative Index to Nursing and Allied Health Literature (CINAHL) databases. The search details are below: ('Infant, Newborn' [MeSH] OR 'neonate*' [Title/Abstract]) AND ('Paracetamol' [MeSH] OR 'Acetaminophen' [Title/Abstract]) AND ('Ductus Arteriosus, Patent/drug therapy' [MeSH] OR 'patent ductus arteriosus' [Title/Abstract]) AND ('Neurodevelopmental Disorders' [MeSH] OR 'neurodevelopment*' [Title/Abstract] OR 'Child Development' [MeSH] OR 'Developmental Disabilities' [MeSH]). All studies were critically appraised and synthesised.

RESULTS

Seven studies reported neurodevelopmental outcomes after paracetamol use for PDA treatment in preterm infants <32 weeks gestation. The studies varied in dosage, route, and duration of paracetamol administration and in the methods used to assess neurodevelopmental outcomes. None of the studies revealed different outcomes between paracetamol-exposed preterm infants and controls.

CONCLUSION

Current low-to-moderate quality evidence suggests no association between paracetamol used for PDA treatment and adverse neurodevelopmental outcomes in preterm infants. Future well-powered studies with standardised neurodevelopmental assessments are warranted to strengthen the current evidence base.

Early neurodevelopmental outcomes of extreme preterm infants exposed to paracetamol: a retrospective cohort study

BACKGROUND

Paracetamol is commonly used for analgesia and patent ductus arteriosus (PDA) treatment in preterm infants. We aimed to evaluate early neurodevelopmental outcomes of extreme preterm infants exposed to paracetamol during their neonatal admission.

METHODS

This retrospective cohort study included surviving infants born at <29 weeks gestation, or with a birth weight of <1000 grams. Neurodevelopmental outcomes studied were early cerebral palsy (CP) or high risk of CP diagnosis, Hammersmith Infant Neurological Examination (HINE) score and Prechtl General Movement Assessment (GMA) at 3-4 months corrected age.

RESULTS

Two hundred and forty-two infants were included, of which 123 were exposed to paracetamol. After adjusting for birth weight, sex and chronic lung disease, there were no significant associations between paracetamol exposure and early CP or high risk of CP diagnosis (aOR 1.46, 95% CI 0.61, 3.5), abnormal or absent GMA (aOR 0.82, 95% CI 0.37, 1.79) or HINE score (adjusted β -0.19, 95% CI -2.39, 2.01). Subgroup analysis stratifying paracetamol exposure into <180 mg/kg or ≥180 mg/kg cumulative dose found that neither had significant effects on outcomes.

CONCLUSIONS

In this cohort of extreme preterm infants, no significant association was found between exposure to paracetamol during the neonatal admission and adverse early neurodevelopment.

IMPACT

Paracetamol is commonly used in the neonatal period for analgesia and patent ductus arteriosus treatment in preterm infants, although prenatal paracetamol use has been associated with adverse neurodevelopmental outcomes. Exposure to paracetamol during the neonatal admission was not associated with adverse early neurodevelopment at 3-4 months corrected age in this cohort of extreme preterm infants. The findings from this observational study is consistent with the small body of literature supporting the lack of association between neonatal paracetamol exposure and adverse neurodevelopmental outcomes in preterm infants.

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.

Acute liver failure secondary to therapeutic paracetamol dosing in an extremely preterm neonate

We report the first case of standard therapeutic dose paracetamol for patent ductus arteriosus closure causing acute liver failure in an extremely preterm infant. After 5 days of treatment, he presented with jaundice, acute severe hepatitis and coagulopathy. Treatment with N-acetyl cysteine resulted in full recovery.

Acetaminophen and Xenobiotic Metabolites in Human Milk and the Development of Bronchopulmonary Dysplasia and Retinopathy of Prematurity in a Cohort of Extremely Preterm Infants

This retrospective cohort study sought to identify the association between certain xenobiotic metabolites in maternal breast milk and the diagnoses of bronchopulmonary dysplasia and retinopathy of prematurity in extremely preterm infants. Several acetaminophen metabolites were associated with a 3- to 6-fold increased odds of these disorders, and metabolites of certain food products, benzoate, and caffeine were associated with decreased odds.

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.

Prophylactic Low-Dose Paracetamol Administration for Ductal Closure and Amplitude-Integrated Electroencephalography in Preterm Infants

INTRODUCTION

Prophylactic low-dose paracetamol administration is used to induce closure of the ductus arteriosus in preterm infants. In our recent study we found no impairment on microstructural maturation processes in the brain of preterm infants at term-equivalent age following prophylactic low-dose paracetamol administration. We now assessed amplitude-integrated electroencephalography (aEEG) signals in preterm infants with and without exposure to prophylactic low-dose paracetamol administration.

METHODS

Infants <32 gestational weeks born between 10/2014 and 12/2018 received prophylactic paracetamol (10 mg/kg intravenously every 8 h until echocardiography after at least 72 h) and form the paracetamol group; infants born between 02/2011 and 09/2014 formed the control group. Four single parameters (continuity, cyclicity, amplitude of lower border, bandwidth span) together with their sum (Burdjalov total score) and presence of sleep-wake cycles were compared between the groups.

RESULTS

Included in the study were 338 infants. Two-hundred and seventeen infants received prophylactic paracetamol and 121 formed the control group. The paracetamol group showed a significantly higher number of sleep-wake cycles per hour and a significantly higher total scores compared to the control group (p < 0.05).

CONCLUSION

Paracetamol exposure has been regarded critically with respect to safety in preterm infants in recent years. We found no impairment on amplitude-integrated electroencephalography signals in preterm infants receiving low-dose prophylactic paracetamol compared to controls. Growing awareness and greater availability of data may encourage the clinicians to administer prophylactic paracetamol for ductal closure in preterm infants. The clinical relevance of our findings has to be evaluated in long-term follow up studies on neurodevelopmental outcome.

Paracetamol (Acetaminophen) and the Developing Brain

Paracetamol is commonly used to treat fever and pain in pregnant women, but there are growing concerns that this may cause attention deficit hyperactivity disorder and autism spectrum disorder in the offspring. A growing number of epidemiological studies suggests that relative risks for these disorders increase by an average of about 25% following intrauterine paracetamol exposure. The data analyzed point to a dose-effect relationship but cannot fully account for unmeasured confounders, notably indication and genetic transmission. Only few experimental investigations have addressed this issue. Altered behavior has been demonstrated in offspring of paracetamol-gavaged pregnant rats, and paracetamol given at or prior to day 10 of life to newborn mice resulted in altered locomotor activity in response to a novel home environment in adulthood and blunted the analgesic effect of paracetamol given to adult animals. The molecular mechanisms that might mediate these effects are unknown. Paracetamol has diverse pharmacologic actions. It reduces prostaglandin formation via competitive inhibition of the peroxidase moiety of prostaglandin H2 synthase, while its metabolite N-arachidonoyl-phenolamine activates transient vanilloid-subtype 1 receptors and interferes with cannabinoid receptor signaling. The metabolite N-acetyl-p-benzo-quinone-imine, which is pivotal for liver damage after overdosing, exerts oxidative stress and depletes glutathione in the brain already at dosages below the hepatic toxicity threshold. Given the widespread use of paracetamol during pregnancy and the lack of safe alternatives, its impact on the developing brain deserves further investigation.

Inflammatory biomarkers in very preterm infants during early intravenous paracetamol administration

BACKGROUND

Paracetamol promotes early closure of patent ductus arteriosus (PDA), and it may affect inflammation after preterm birth.

OBJECTIVE

The aim of this study was to evaluate the association between paracetamol treatment and serum inflammatory biomarkers in very preterm infants with respiratory distress.

STUDY DESIGN

The infants were randomly assigned to intravenous paracetamol or placebo during the first 4 days of life, and others received a lower dose of paracetamol unblinded. Serum samples were used for the analysis of 10 cytokines, C-reactive protein (CRP) and malondialdehyde (MDA). The impact of paracetamol on the biomarkers was evaluated, based on the levels during the early (<60 h) and the later (60-120 h) postnatal age.

RESULTS

Altogether, 296 serum samples from 31 paracetamol and 25 placebo group infants were analysed. Paracetamol had no effect on cytokine levels during the first 60 h when most induced PDA contractions took place. Later paracetamol treatment was associated with lower serum levels of several cytokines, including interleukin (IL-) 10, interferon gamma-induced protein (IP-) 10, and monocyte chemoattractant protein-1. CRP levels were lower in the paracetamol group during the early treatment. Amongst the infants who had severe morbidities, MDA was higher (p = .045), regardless of paracetamol treatment.

CONCLUSION

No significant differences in the cytokine levels were evident between the treatment and placebo groups. However, during early treatment, CRP levels were lower in the paracetamol group. To clarify whether this was due to a decrease in cardiopulmonary distress, or a distinct anti-inflammatory effect, requires further studies.

Early closure mechanisms of the ductus arteriosus in immature infants

AIM

According to experimental studies, cardiopulmonary distress decreases after closure of patent ductus arteriosus. However, early closure of the ductus using ibuprofen or indomethacin has failed to increase survival without serious morbidity. We review relevant data aiming to define optimal early management strategies that promote early closure of ductus arteriosus without serious adverse effects.

METHODS

Literature in English was searched selectively focusing on the potential of using acetaminophen for early closure of the ductus.

RESULTS

Prophylactic ibuprofen or indomethacin intended to close the ductus, predisposes infants to ischaemia, bleeding and immune dysfunction. Acetaminophen appears to have a similar efficacy as indomethacin or ibuprofen, and all three dose-dependently constrict the ductus. Ibuprofen and indomethacin cause non-specific inhibition of prostaglandin synthesis, while acetaminophen predominantly inhibits prostaglandin E synthesis. Owing to low CYP450 activity in infancy, acetaminophen toxicity has been rarely evident. However, increasing the dosage increases the oxidative stress. We review prophylactic treatments that may increase the safety and efficacy of acetaminophen. These include vitamin A, cysteine and glutamine, and low-dose corticosteroid supplementation.

CONCLUSION

The current challenge is to define a safe perinatal management practice that promotes cardiorespiratory adaptation in immature infants, particularly the seamless closure of the ductus before significant cardiopulmonary distress develops.

Massive Gastric Hemorrhage after Indomethacin Therapy: A Rare Presentation and Critical Management in an Extremely Preterm Infant

Indomethacin has been widely used in preterm infants with hemodynamically significant patent ductus arteriosus (PDA). Gastrointestinal complications of indomethacin have been reported in 5% of treated neonates. However, massive gastric mucosa hemorrhage is a rarely reported complication. To the best of our knowledge, the infant in this report is the smallest reported in the literature to have undergone successful surgery for such a complication. A male preterm infant weighing 566 g was born at 25^2/7 weeks of gestational age without a complicated maternal history. Soon after birth, he received nasal noninvasive respiratory support and minimal feeding. PDA was observed since the first day of life (DOL), treatments were initiated on the second DOL for the hemodynamical significance, and PDA was closed after two courses of indomethacin therapy (0.2 mg/kg). At midnight on the seventh DOL, generalized pallor, bloody gastric drainage, and a distended stomach were observed. Massive gastric bleeding was suspected. He suffered from intermittent hypotension, which was corrected with blood products and fluid resuscitation under monitoring with a radial arterial line. Gastric lavage with cooling saline was performed twice but in vain. Prior to surgical consultation, intravascular volume transfusion was given twice. An exploratory laparotomy was arranged after obtaining the parents' consent. Blood oozing from the gastric mucosa was observed through gastrostomy and was successfully stopped via epinephrine-soaked gauze compression. After the operation, his clinical course remained uneventful, and he was discharged without neurological anomaly at two-year follow-up. Physicians need to be cautious of indomethacin's effect on platelet dysfunction in preterm infants with multiple predisposing factors. The tendency for mucosal bleeding should be continuously monitored after indomethacin therapy.

Acetaminophen Therapy for Persistent Patent Ductus Arteriosus

Persistence of a left-to-right shunt caused by a patent ductus arteriosus (PDA) leads to significant sequelae in extremely premature infants as a result of pulmonary overcirculation and systemic steal. Although timing and duration of treatment for a persistent clinically significant PDA differ among institutions, standard pharmacologic interventions are the nonsteroidal anti-inflammatory drugs indomethacin and ibuprofen. Acetaminophen has emerged as an alternative to indomethacin and ibuprofen with less significant adverse effects, but there is no consensus regarding its use. This review summarizes the most recent evidence for the use of acetaminophen in PDA treatment.

Intravenous paracetamol for neonates: long-term diseases not escalated during 5 years of follow-up

OBJECTIVE

To evaluate the long-term adverse reactions of paracetamol in children who required intensive care shortly after birth. Paracetamol is a widely used analgesic in neonates, but the long-term studies are lacking. Previous epidemiological studies have reported associations between early paracetamol intake and diseases in childhood.

DESIGN

Five-year follow-up cohort of children who required intensive care shortly after birth.

SETTING

Single tertiary care hospital; neonatal and paediatric intensive care units.

INTERVENTIONS

Intravenous paracetamol was administered for pain and discomfort to the neonates during their intensive care, while for the control infants, it was not available.

MAIN OUTCOME MEASURES

The primary outcome was the incidence of asthma; secondary outcomes were neonatal diseases and long-term morbidities (atopic dermatitis, inflammatory bowel disease, autism, speech disorders, cerebral palsy). Long-term morbidities were adjusted based on antenatal and neonatal risk factors.

RESULTS

We screened all neonates admitted to the intensive care units soon after birth in Oulu University Hospital, Oulu, Finland, during 1 October 2007 to 31 December 2013. Altogether, 1552 infants needed intensive care. Of them, 735 (47%) were treated with intravenous paracetamol. We obtained their long-term data from the Finnish National Institute for Health and Welfare, including all physician-made diagnoses from all primary healthcare units and hospitals in Finland. We found no difference in the asthma incidence or in other long-term morbidities between paracetamol-treated and non-exposed infants.

CONCLUSIONS

Intravenous paracetamol given to neonates did not associate with childhood disorders compared with the non-exposed infants during the 5-year follow-up. The previous hypothesis that early paracetamol use causes childhood morbidities was not confirmed.

Trial of paracetamol for premature newborns: five-year follow-up

INTRODUCTION

Paracetamol is a commonly used pain medication for the very-high risk neonates and it is increasingly being used for patent ductus arteriosus treatment in preterm infants. However, randomized trial data on long-term consequences are not yet available, but there is some evidence of serious adverse effects on children exposed to paracetamol during pregnancy.

PATIENTS AND METHODS

A five-year follow-up study of a placebo-controlled paracetamol trial on very preterm infants (PreParaS) was conducted (n = 48). Using a web-based parental questionnaire, parents answered questions about their children's cardiac and respiratory symptoms, allergies, neurodevelopment, infections, medications and hospitalizations.

RESULTS

Most parents reported that their child had normal development (paracetamol 79% vs. placebo 65%). Physician-diagnosed asthma or allergy (paracetamol 10.5% vs. placebo 25.0%), or hospitalization due to respiratory symptoms (0 vs. 15%) were uncommon and neurological or neuro-psychiatric symptoms were rare.

CONCLUSIONS

Current follow-up results on paracetamol-exposed very preterm infants may not be alarming suggesting that paracetamol administration shortly after birth is not associated with common adverse consequences.

Is late treatment with acetaminophen safe and effective in avoiding surgical ligation among extremely preterm neonates with persistent patent ductus arteriosus?

OBJECTIVE

Evaluate the association of late treatment with acetaminophen vs. immediate surgical ligation with death or neurodevelopmental impairment (NDI) among extremely low gestational age neonates (ELGANs) with persistent patent ductus arteriosus (pPDA).

STUDY DESIGN

Retrospective comparative epoch study of ELGANs with pPDA being considered for surgical ligation. ELGANs in epoch 1 (2009-2012) were referred for ligation, while infants in epoch 2 (2012-2015) were treated with oral acetaminophen and referred for ligation in the absence of improvement. The primary outcome was a composite of death/NDI at 18-24 months.

RESULTS

Ninety-two ELGANs with median[IQR] GA 25.2 weeks [24.4, 26.3] had pPDA (43 in epoch 1, 49 in -epoch 2) with acetaminophen-exposed neonates receiving 7 days [7, 7] of treatment. ELGANs in epoch 2 had reduced ligation (aOR 0.30; 95%CI: [0.11, 0.87]), but there was no difference in death/NDI (aOR 1.03; 95%CI: [0.30, 3.56]).

CONCLUSIONS

Late treatment with acetaminophen to avoid surgery for pPDA is associated with reduced ligation but no difference in death/NDI, supporting the safety and effectiveness of this approach.

Factors Associated With Benefit of Treatment of Patent Ductus Arteriosus in Preterm Infants: A Systematic Review and Meta-Analysis

Context: There is an ongoing debate on the optimal management of patent ductus arteriosus (PDA) in preterm infants. Identifying subgroup of infants who would benefit from pharmacological treatment might help. Objective: To investigate the modulating effect of the differences in methodological quality, the rate of open-label treatment, and patient characteristics on relevant outcome measures in randomized controlled trials (RCTs). Data Sources: Electronic database search between 1950 and May 2020. Study Selection: RCTs that assessed pharmacological treatment compared to placebo/no treatment. Data Extraction: Data is extracted following the PRISMA guidelines. Outcome measures were failure to ductal closure, surgical ligation, incidence of necrotizing enterocolitis, bronchopulmonary dysplasia, sepsis, periventricular leukomalacia, intraventricular hemorrhage (IVH) grade ≥3, retinopathy of prematurity and mortality. Results: Forty-seven studies were eligible. The incidence of IVH grade ≥3 was lower in the treated infants compared to the placebo/no treatment (RR 0.77, 95% CI 0.64-0.94) and in the subgroups of infants with either a gestational age <28 weeks (RR 0.77, 95% CI 0.61-0.98), a birth weight <1,000 g (RR 0.77, 95% CI 0.61-0.97), or if untargeted treatment with indomethacin was started <24 h after birth (RR 0.70, 95% CI 0.54-0.90). Limitations: Statistical heterogeneity caused by missing data and variable definitions of outcome parameters. Conclusions: Although the quality of evidence is low, this meta-analysis suggests that pharmacological treatment of PDA reduces severe IVH in extremely preterm, extremely low birth weight infants or if treatment with indomethacin was started <24 h after birth. No other beneficial effects of pharmacological treatment were found.

Early treatment versus expectant management of hemodynamically significant patent ductus arteriosus for preterm infants

BACKGROUND

Patent ductus arteriosus (PDA) is associated with significant morbidity and mortality in preterm infants. Nonsteroidal anti-inflammatory drugs (NSAIDs) are used to prevent or treat a PDA. There are concerns regarding adverse effects of NSAIDs in preterm infants. Controversy exists on whether early targeted treatment of a hemodynamically significant (hs) PDA improves clinical outcomes.

OBJECTIVES

To assess the effectiveness and safety of early treatment strategies versus expectant management for an hs-PDA in reducing mortality and morbidity in preterm infants.

SEARCH METHODS

We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL 2019, Issue 6) in the Cochrane Library; MEDLINE via PubMed (1966 to 31 May 2019), Embase (1980 to 31 May 2019), and CINAHL (1982 to 31 May 2019). An updated search was run on 2 October 2020 in the following databases: CENTRAL via CRS Web and MEDLINE via Ovid. We searched clinical trial databases, conference proceedings, and the reference lists of retrieved articles for randomized controlled trials (RCT) and quasi-randomized trials.

SELECTION CRITERIA

We included RCTs in which early pharmacological treatment, defined as treatment initiated within the first seven days after birth, was compared to no intervention, placebo or other non-pharmacological expectant management strategies for treatment of an hs-PDA in preterm (< 37 weeks' postmenstrual age) or low birth weight (< 2500 grams) infants.

DATA COLLECTION AND ANALYSIS

We performed data collection and analyses in accordance with the methods of Cochrane Neonatal. Our primary outcome was all-cause mortality during hospital stay. We used the GRADE approach to assess the certainty of evidence for selected clinical outcomes.

MAIN RESULTS

We included 14 RCTs that enrolled 910 infants. Seven RCTs compared early treatment (defined as treatment initiated by seven days of age) versus expectant management and seven RCTs compared very early treatment (defined as treatment initiated by 72 hours of age) versus expectant management. No difference was demonstrated between early treatment versus expectant management (no treatment initiated within the first seven days after birth) for an hs-PDA for the primary outcome of 'all-cause mortality' (6 studies; 500 infants; typical RR 0.80, 95% CI 0.46 to 1.39; typical RD -0.02; 95% CI -0.07 to 0.03; moderate-certainty evidence), or other important outcomes such as surgical PDA ligation (4 studies; 432 infants; typical RR 1.08, 95% CI 0.65 to 1.80; typical RD -0.03; 95% CI -0.09 to 0.03; very low-certainty evidence), chronic lung disease (CLD) (4 studies; 339 infants; typical RR 0.90, 95% CI 0.62 to 1.29; typical RD -0.03; 95% CI -0.10 to 0.03; moderate-certainty evidence), severe intraventricular hemorrhage (IVH) (2 studies; 171 infants; typical RR 0.83,95% CI 0.32 to 2.16; typical RD -0.01; 95% CI -0.08 to 0.06; low-certainty evidence), and necrotizing enterocolitis (NEC) (5 studies; 473 infants; typical RR 2.34,95% CI 0.86 to 6.41; typical RD 0.04; 95% CI 0.01 to 0.08; low-certainty evidence). Infants receiving early treatment in the first seven days after birth were more likely to receive any PDA pharmacotherapy compared to expectant management (2 studies; 232 infants; typical RR 2.30, 95% CI 1.86 to 2.83; typical RD 0.57; 95% CI 0.48 to 0.66; low-certainty evidence). No difference was demonstrated between very early treatment versus expectant management (no treatment initiated within the first 72 hours after birth) for an hs-PDA for the primary outcome of 'all-cause mortality' (7 studies; 384 infants; typical RR 0.94, 95% CI 0.58 to 1.53; typical RD -0.03; 95% CI -0.09 to 0.04; moderate-certainty evidence) or other important outcomes such as surgical PDA ligation (5 studies; 293 infants; typical RR 0.88, 95% CI 0.36 to 2.17; typical RD -0.01; 95% CI -0.05 to 0.02; moderate-certainty evidence), CLD (7 studies; 384 infants; typical RR 0.83, 95% CI 0.63 to 1.08; typical RD -0.05; 95% CI -0.13 to 0.04; low-certainty evidence), severe IVH (4 studies, 240 infants; typical RR 0.64, 95% CI 0.21 to 1.93; typical RD -0.02; 95% CI -0.07 to 0.04; moderate-certainty evidence), NEC (5 studies; 332 infants; typical RR 1.08, 95% CI 0.53 to 2.21; typical RD 0.01; 95% CI -0.04 to 0.06; moderate-certainty evidence) and neurodevelopmental impairment (1 study; 79 infants; RR 0.27, 95% CI 0.03 to 2.31 for moderate/severe cognitive delay at 18 to 24 months; RR 0.54, 95% CI 0.05 to 5.71 for moderate/severe motor delay at 18 to 24 months; RR 0.54, 95% CI 0.10 to 2.78 for moderate/severe language delay at 18 to 24 months; low-certainty evidence). Infants receiving very early treatment in the first 72 hours after birth were more likely to receive any PDA pharmacotherapy compared to expectant management (4 studies; 156 infants; typical RR 1.64, 95% CI 1.31 to 2.05; typical RD 0.69; 95% CI 0.60 to 0.79; very low-certainty evidence). Very early treatment, however, shortened the duration of hospitalization compared to expectant management (4 studies; 260 infants; MD -5.35 days; 95% CI -9.23 to -1.47; low-certainty evidence).

AUTHORS' CONCLUSIONS

Early or very early pharmacotherapeutic treatment of an hs-PDA probably does not reduce mortality in preterm infants (moderate-certainty evidence). Early pharmacotherapeutic treatment of hs-PDA may increase NSAID exposure (low-certainty evidence) without likely reducing CLD (moderate-certainty evidence), severe IVH or NEC (low-certainty evidence). We are uncertain whether very early pharmacotherapeutic treatment of hs-PDA also increases NSAID exposure (very low-certainty evidence). Very early treatment probably does not reduce surgical PDA ligation, severe IVH or NEC (moderate-certainty evidence), and may not reduce CLD or neurodevelopmental impairment (low-certainty evidence). Additional large trials that specifically include preterm infants at the highest risk of PDA-attributable morbidity, are adequately powered for patient-important outcomes and are minimally contaminated by open-label treatment are required to explore if early targeted treatment of hs-PDA improves clinical outcomes. There are currently two trials awaiting classification and two ongoing trials exploring this question.

How to translate neurocognitive and behavioural outcome data in animals exposed to paracetamol to the human perinatal setting?

Introduction

There are epidemiological - not necessary causal - observations that link perinatal paracetamol (acetaminophen) exposure to impaired neuro-cognition and behaviour, but animal models may assist to better understand the mechanisms.

Material and methods

To provide an overview on preclinical data and mechanisms explored, we conducted a structured literature search on animal models and neuro-cognition and behavioural outcome following perinatal paracetamol exposure.

Results

This search resulted in 20 papers (rat (n = 9), zebrafish larvae (n = 6), mice (n = 5)), published between 2009 and 2020. Eight discussed pregnancy/fetal paracetamol exposure, 6 juvenile, 6 studies combined pregnancy and juvenile exposure. Quality assessment (SYRCLE's bias risk) showed a heterogeneous pattern with blinding issues. Most papers (n = 16) described paracetamol exposure without indication, except for an induced fever and repetitive needle pricking (rat), brain injury (mice), and a zebrafish nociception model. Reported outcomes related to biochemistry (mono-amines, amino acids, protein expression), anatomy (teratogen, morphology, nuclear size) or behaviour (spatial memory, motor, social behaviour and exploration, sexual behaviour). On mechanisms, the cumulative data support an interesting 'cannabinoid' hypothesis to link paracetamol to neuro-cognitive and behavioural outcome. Besides limited species diversity, there is relevant within-species paracetamol dosing variability (dose, duration) with undocumented exposure.

Conclusions

Models should further integrate clinical indications, as non-exposure is the obvious safest setting in the absence of an indication. Besides pain and fever and related to the cannabinoid hypothesis, this should include perinatal brain injury, as there is animal experimental evidence that cannabinoids are neuroprotective in newborn brain injury or asphyxia, further supported by evidence from non-perinatal models of paracetamol-related neuroprotective effects.

Molecular and Mechanical Mechanisms Regulating Ductus Arteriosus Closure in Preterm Infants

Failure of ductus arteriosus closure after preterm birth is associated with significant morbidities. Ductal closure requires and is regulated by a complex interplay of molecular and mechanical mechanisms with underlying genetic factors. In utero patency of the ductus is maintained by low oxygen tension, high levels of prostaglandins, nitric oxide and carbon monoxide. After birth, ductal closure occurs first by functional closure, followed by anatomical remodeling. High oxygen tension and decreased prostaglandin levels mediated by numerous factors including potassium channels, endothelin-1, isoprostanes lead to the contraction of the ductus. Bradykinin and corticosteroids also induce ductal constriction by attenuating the sensitivity of the ductus to PGE2. Smooth muscle cells of the ductus can sense oxygen through a mitochondrial network by the role of Rho-kinase pathway which ends up with increased intracellular calcium levels and contraction of myosin light chains. Anatomical closure of the ductus is also complex with various mechanisms such as migration and proliferation of smooth muscle cells, extracellular matrix production, endothelial cell proliferation which mediate cushion formation with the interaction of blood cells. Regulation of vessel walls is affected by retinoic acid, TGF-β1, notch signaling, hyaluronan, fibronectin, chondroitin sulfate, elastin, and vascular endothelial cell growth factor (VEGF). Formation of the platelet plug facilitates luminal remodeling by the obstruction of the constricted ductal lumen. Vasa vasorum are more pronounced in the term ductus but are less active in the preterm ductus. More than 100 genes are effective in the prostaglandin pathway or in vascular smooth muscle development and structure may affect the patency of ductus. Hemodynamic changes after birth including fluid load and flow characteristics as well as shear forces within the ductus also stimulate closure. Current pharmacological treatment for the closure of a patent ductus is based on the blockage of the prostaglandin pathway mainly through COX or POX inhibition, albeit with some limitations and side effects. Further research for new agents aiming ductal closure should focus on a clear understanding of vascular biology of the ductus.

Subgroup analysis of the early paracetamol trial to preterm infants found haemodynamic changes and improved oxygenation

BACKGROUND

We previously reported in a randomised trial that early intravenous paracetamol accelerated contraction of ductus arteriosus in very preterm infants (<32 gestation weeks).

AIMS

To monitor sequentially paracetamol effects on the blood pressure and brain tissue oxygenation in the infants participating the trial.

METHODS

In a double-blind trial, intravenous paracetamol or placebo was infused to 48 very premature infants starting within 24 h of birth for four days. Besides the ductus arteriosus, we systematically measured blood pressure, peripheral (spO₂) and regional cerebral oxygen saturation (rcSO₂), and cerebral fractional tissue oxygen extraction (cFTOE) during the study period.

RESULTS

Compared to the placebo, the paracetamol loading dose transiently decreased the arterial blood pressure. During treatment, the paracetamol-treated infants had higher spO₂ (p = .042) and rcSO₂ (p = .036) values than the placebo group infants. Additionally, the cFTOE values were lower in the paracetamol group during the study without statistical significance. All infants with closed ductus had higher tissue oxygenation and a lower cFTOE than infants with open ductus.

CONCLUSIONS

Paracetamol caused modest haemodynamic effects and increased cerebral oxygenation. They were mostly due to early contraction of ductus. Additional direct drug-effects in brain are not ruled-out.

A Critical Review on the Relevance of Paracetamol for Procedural Pain Management in Neonates

Effective and safe pain relief in neonates matters. This is not only because of ethical constraints or human empathy, but even more because pain treatment is an important and crucial part of contemporary medical, paramedical, and nursing care to improve the outcome in neonatal intensive care graduates. Paracetamol (acetaminophen) is likely one of the pharmacological tools to attain this, with data on prescription practices suggesting that paracetamol is somehow the "rising star" in neonatal pain management. Besides very rare topical clinical scenarios like peripartal asphyxia and subsequent whole body hypothermia or the use of cardiorespiratory support devices, data on paracetamol pharmacokinetics and metabolism were reported throughout neonatal age or weight ranges, and we have summarized these data. In this review, we subsequently aimed to provide the reader with the currently available observations on the use of paracetamol as analgesic for different pain syndromes (major surgery, minor surgery or trauma, and procedural pain), with focus on the limitations of paracetamol when prescribed for neonatal procedural pain management. We hereby intentionally will not discuss other indications (patent ductus arteriosus and fever) for paracetamol administration in neonates. Based on the available evidence, paracetamol has opioid-sparing effects for major pain syndromes, is effective to treat minor to moderate pain syndromes, but fails for effective procedural pain management in neonates. This efficacy failure for procedural pain management should stimulate us to continue to search for more effective interventions, including non-pharmacological interventions and preventive strategies. Furthermore, there are also upcoming association type of epidemiological studies on the relation between exposure to analgesics-including paracetamol-and the negative short- or long-term outcome characteristics (neuro-behavioral, atopy, and fertility). Consequently and in addition to the search for effective alternatives to prevent or treat pain, studies on long-term outcome following paracetamol exposure are needed to inform all stakeholders on the full effect-side effect balance of the different strategies to treat pain.

Efficacy and Safety of Paracetamol for Patent Ductus Arteriosus Closure in Preterm Infants: An Updated Systematic Review and Meta-Analysis

Background: Indomethacin and ibuprofen, two commonly used prostaglandin inhibitors, are the drugs of choice for patent ductus arteriosus. However, paracetamol is an alternative choice when these drugs are ineffective or contraindicated. This study aimed to confirm paracetamol's efficacy and safety compared with those of other drugs or placebos for patent ductus arteriosus closure in premature infants. Methods: We conducted a literature search using the Cochrane Library, PubMed, CINAHL, and EMBASE databases for randomized controlled trials and quasi-randomized controlled trials. We used the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to direct the process and PICO (P, population; I, intervention/interest; C, comparator; O, outcome) principle to constitute the theme. We combined the research data through qualitative summaries or meta-analyses. Results: The final analyses included 15 trials (N = 1,313). No significant differences were noted between paracetamol and ibuprofen except for shorter mean days needed for patent ductus arteriosus closure, lower risk of gastrointestinal bleeding, and hyperbilirubinemia. No significant difference existed between paracetamol and indomethacin. Oral paracetamol was more effective than placebo in infants weighing 1,501-2,500 g. Conclusions: Our study findings tentatively conclude that paracetamol can induce early patent ductus arteriosus closure without significant side effects but that its efficacy is not superior to that of indomethacin.