A comparison of magnesium sulphate and sildenafil in the treatment of the newborns with persistent pulmonary hypertension: a randomized controlled trial

Perioperative sildenafil therapy in pulmonary hypertension associated with congenital cardiac disease: An updated meta-analysis

To provide an updated meta-analysis to evaluate the efficacy and safety of sildenafil on pediatric patients with pulmonary hypertension (PH) associated with congenital heart disease (CHD). To assess the efficacy and safety of sildenafil, five outcomes, time duration of post-operative need for mechanical ventilation, time duration of post-operative ICU stay, length of hospitalization (LOH), the incidence of mortalities and pulmonary arterial pressure to aortic pressure ratio (PAP/AoP) were regarded as primary efficacy outcomes. Standardized mean difference (SMD) was calculated for continuous data. In comparison to the control group (CG), there was a significant decrease in the time duration of ICU stay in the sildenafil group (SG) (SMD = -0.61 [95% CI -1.17, 0.04]; P < 0.01, I2 = 85%). Length of hospitalization was assessed in the sildenafil and control groups (SMD = -0.18 [95% CI -0.67, 0.31] P = 0.05, I2 = 62%). However, there was no significant difference seen in mortality rates between the SG and CG (SMD = 0.53 [ 95% CI 0.13, 2.17] p = 0.61, I2 = 0%), in the time duration of postoperative mechanical ventilation between the SG and CG (SMD = -0.23 [95% CI -0.49, 0.03] p = 0.29, I2 = 19%), or PAP/AoP ratio between the SG and CG (SMD = -0.42 [95% CI -1.35, 0.51] P < 0.01, I2 = 90%). Based on our analysis, sildenafil has little to no effect in reducing postoperative morbidity and mortality due to PH in infants and children with CHD.

Comparison of Different Treatments of Persistent Pulmonary Hypertension of the Newborn: A Systematic Review and Network Meta-Analysis

OBJECTIVES

Persistent pulmonary hypertension of the newborn (PPHN) is a life-threatening disease. Despite being considered the gold standard treatment scheme, inhaled nitric oxide (iNO) is not readily available in settings with limited resources. Therefore, in recent years, research on related drugs is being actively pursued. Herein, we aimed to use random-effects network meta-analysis to evaluate the efficacy and associated mortality of different PPHN therapies.

DATA SOURCES

We electronically searched the PubMed, Embase, and Cochrane Library for data up to January 27, 2023.

STUDY SELECTION

Randomized controlled trials involving neonates with PPHN assessing efficacy and mortality of various treatments.

DATA EXTRACTION

Details of study population, treatments, and outcomes were extracted.

DATA SYNTHESIS

Direct pairwise comparisons and a network meta-analysis was performed under random effects. The ranking probability was further assessed based on the surface under the cumulative ranking curve (SUCRA). We analyzed 23 randomized clinical trials involving 902 newborns with PPHN. Sixteen different treatment strategies were compared with each other and conventional therapy (CON). A median concentration of 10-20 parts per million (ppm) iNO (MNO) coupled with sildenafil orally administered at a dose of 1-3 mg/kg/dose every 6-8 hours (OSID) demonstrated the best efficacy (MNO + OSID vs. CON: odds ratio [OR] = 27.53, 95% CI, 2.36-321.75; SUCRA = 0.818, ranking first; moderate quality). OSID combined with milrinone administered IV also performed well in terms of efficacy (OSID + milrinone vs. CON: OR = 25.13, 95% CI = 1.67-377.78; SUCRA = 0.811, ranking second; low quality) and mortality reduction (CON vs. OSID + milrinone: OR = 25.13, 95% CI = 1.67-377.78; SUCRA = 0.786, ranking last; low quality).

CONCLUSIONS

MNO + OSID is the most effective PPHN treatment. If iNO is not available, OSID + milrinone is preferred.

Efficacy and safety of endothelin receptor antagonists, phosphodiesterase type 5 Inhibitors, and prostaglandins in pediatric pulmonary arterial hypertension: A network meta-analysis

Background

Pulmonary arterial hypertension (PAH) is a fatal disease characterized by pulmonary vascular remodeling and increased pulmonary artery pressure, leading to impaired lung oxygenation, right heart failure, and even death. Although great advances have been made in PAH-targeted medications for pediatric patients, the efficacy and safety of these treatments are controversial.

Methods

We retrieved relevant articles from electronic databases including PubMed, EMBASE, Web of Science, and Cochrane Library until 12 April 2022. To compare the effectiveness and safety of endothelin receptor antagonists (ERAs), phosphodiesterase type 5 Inhibitors (PDE-5i), and prostaglandins (ProA) in the treatment of pediatric PAH, we investigated six hemodynamic parameters, four respiratory parameters, intensive care unit (ICU) stay duration, length of hospital stay, and two safety outcomes.

Results

A total of 27 randomized controlled trials (RCTs) were included in the meta-analysis with 1,574 pediatric participants. The duration of mechanical ventilation was shorter for patients using bosentan, sildenafil, and ProsA, compared with that for patients using the placebo. Bosentan helped to shorten more time for mechanical ventilation than ProsA did, while ProsA was more effective than sildenafil in this respect. As for the length of stay in the ICU, patients administered by ProsA or sildenafil needed shorter ICU stay, compared to those using the placebo, while ProsA was more effective for shortening ICU stay time. In light of safety outcomes, there was a statistically significant difference between the sildenafil and the placebo group. Sildenafil surpassed ProsA in reducing the incidence of pulmonary hypertension (PH) crisis.

Conclusions

ERAs were more effective than ProsA in shortening the duration of mechanical ventilation, while ProsA were better for shortening the duration of mechanical ventilation and ICU stay than PDE-5i. PDE-5i were found to generate more benefits in decreasing the occurrence of PH crisis, though further investigation is warranted.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=351505.

Oral versus intravenous sildenafil for pulmonary hypertension in neonates: a randomized trial

BACKGROUND

Sildenafil is the drug of choice for neonatal pulmonary hypertension in developing countries where inhaled nitric oxide is not available. Available as oral and intravenous preparation - no study has been done in the past to compare the two forms. Each has its own benefits - but requires comparison in terms of efficacy and safety. This study was done to compare the efficacy of oral versus intravenous (IV) sildenafil in infants with mild to moderate pulmonary hypertension.

METHODS

An open labelled randomized trial was conducted in a neonatal intensive care unit of urban tertiary hospital in western India between February 2019 to December 2020. Infants born after 34 weeks of gestation with Pulmonary arterial pressure (PAP) > 25 mm Hg measured by echocardiography, within 72 h of birth, were enrolled for the study. Participants were randomly assigned to receive sildenafil either orally or by intravenous route. Primary outcome was the time taken for PAP to decrease below 25 mm Hg. Secondary outcomes were time taken for oxygenation index to decrease by 25%, duration of invasive and non-invasive mechanical ventilation, nasal oxygen, hospital stay, time to achieve full feeds, mortality, and side effects.

RESULTS

Forty patients were enrolled. The baseline characteristics of neonates in both groups were similar except for APGAR scores at 1 min and 5 min, with oral group having lower score [MEDIAN (IQR) 5.00 (4.00- 7.00) and 7.00 (6.00- 8.00)] compared to IV group [MEDIAN (IQR) 7.00 (6.00-8.00) and 9.00 (8.00-9.00)] respectively. Time taken for PAP to decrease below 25 mm was not statistically different between the oral and intravenous groups. Systemic hypotension occurred in 4 neonates of the intravenous group but none in the oral group.

CONCLUSION

Oral and intravenous sildenafil had equal efficacy at reducing PAP in neonatal pulmonary hypertension, albeit intravenous sildenafil use was associated with a greater complication rate.

TRIAL REGISTRATION

Trial was registered in the clinical trials registry of India [ CTRI/2019/04/018781 ][25/04/2019].

Pediatric Pulmonary Hypertension: Definitions, Mechanisms, Diagnosis, and Treatment

Pediatric pulmonary hypertension (PPH) is a multifactorial disease with diverse etiologies and presenting features. Pulmonary hypertension (PH), defined as elevated pulmonary artery pressure, is the presenting feature for several pulmonary vascular diseases. It is often a hidden component of other lung diseases, such as cystic fibrosis and bronchopulmonary dysplasia. Alterations in lung development and genetic conditions are an important contributor to pediatric pulmonary hypertensive disease, which is a distinct entity from adult PH. Many of the causes of pediatric PH have prenatal onset with altered lung development due to maternal and fetal conditions. Since lung growth is altered in several conditions that lead to PPH, therapy for PPH includes both pulmonary vasodilators and strategies to restore lung growth. These strategies include optimal alveolar recruitment, maintaining physiologic blood gas tension, nutritional support, and addressing contributing factors, such as airway disease and gastroesophageal reflux. The outcome for infants and children with PH is highly variable and largely dependent on the underlying cause. The best outcomes are for neonates with persistent pulmonary hypertension (PPHN) and reversible lung diseases, while some genetic conditions such as alveolar capillary dysplasia are lethal. © 2021 American Physiological Society. Compr Physiol 11:2135-2190, 2021.

Inadequate Dosage May Lead to the Recurrence of Postoperative Pulmonary Hypertension in Patients With Congenital Heart Disease

Background: Pulmonary arterial hypertension (PAH) associated with congenital heart disease (PAH-CHD) occurs predominantly among patients with uncorrected congenital heart disease (CHD). It is an intractable problem to control PAH continuously and stably after an operation.

Methods: 1) OPLS-DA combined with S-plot was used to retrospectively analyze the results of preoperative and postoperative PAH and 39 biochemical indicators of 235 patients admitted to Fuwai Yunnan Cardiovascular Hospital from January 2019 to December 2020. 2) Combined with Meta-analysis, the recurrence in postoperative PAH was analyzed in terms of operation factors, doses administered, and age factors.

Results: 1) 4 indicators (PAH, RBC, HGB, and CO₂) that reflect the prognosis of patients had been found by OPLS-DA combined with S-plot. 2) The recurrence rate of postoperative PAH was 37.02%. The comprehensive therapeutic effect of interventional closure was better than that of surgical operation. PAH was not significantly higher again in patients who received either the instruction dose or the literature dose. Postoperative combination therapy (bosentan and sildenafil) was more effective than bosentan alone. Recovery after treatment was better in infants than in the other four age groups.

Conclusion: OPLS-DA combined with S-plot was used for the first time to analyze clinical examination data. In this study, this method proved to be a feasible method for analyzing clinical data We recommend interventional closure as the first choice for patients with PAH-CHD. For postoperative oral therapy, we recommend the combination therapy (bosentan with sildenafil). To prevent the recurrence, the dose should be strictly prescribed according to the instructions, literature, or body surface area converted. Moreover, we recommend treatment at a young age in these patients.

The Efficacy and Safety of Pulmonary Vasodilators in Pediatric Pulmonary Hypertension (PH): A Systematic Review and Meta-analysis

Background: We performed a meta-analysis to evaluate the efficacy and safety of pulmonary vasodilators in pediatric pulmonary hypertension (PH) patients. Methods: We searched electronic databases including PubMed, EMBASE, and the Cochrane Library up to May 2020, and conducted a subgroup analysis for pulmonary vasodilators or underlying disease. Results: Fifteen studies with 719 pediatric PH patients were included in the meta-analysis. Adverse events did not differ (p = 0.11, I ² = 15%) between the pulmonary vasodilators group and the control group, neither in the subgroups. In total, compared with the control group treatment, pulmonary vasodilators significantly decreased the mortality (p = 0.002), mean pulmonary artery pressure (mPAP, p = 0.02), and mechanical ventilation duration (p = 0.03), also improved the oxygenation index (OI, p = 0.01). In the persistent pulmonary hypertension of the newborn (PPHN) subgroup, phosphodiesterase type 5 inhibitors (PDE5i) significantly reduced mortality (p = 0.03), OI (p = 0.007) and mechanical ventilation duration (p = 0.004). Administration of endothelin receptor antagonists (ERAs) improved OI (p = 0.04) and mechanical ventilation duration (p < 0.00001) in PPHN. We also found that in the pediatric pulmonary arterial hypertension (PPAH) subgroup, mPAP was pronouncedly declined with ERAs (p = 0.006). Systolic pulmonary artery pressure (sPAP, p < 0.0001) and pulmonary arterial/aortic pressure (PA/AO, p < 0.00001) were significantly relieved with PDE5i, partial pressure of arterial oxygen (PaO₂) was improved with prostacyclin in postoperative PH (POPH) subgroup (p = 0.001). Compared with the control group, pulmonary vasodilators could significantly decrease PA/AO pressure (p < 0.00001) and OI (p < 0.00001) in the short-term (duration <7 days) follow-up subgroup, improve mPAP (p = 0.03) and PaO₂ (p = 0.01) in the mid-term (7-30 days) follow-up subgroup, also decrease mortality, mPAP (p = 0.0001), PA/AO pressure (p = 0.0007), duration of mechanical ventilation (p = 0.004), and ICU stay (p < 0.00001) in the long-term follow subgroup (>30 days). Conclusion: Pulmonary vasodilators decrease the mortality in pediatric PH patients, improve the respiratory and hemodynamic parameters, reduce the mechanical ventilation duration.

Clinical guidelines for the treatment of congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is a birth defect of the diaphragm in which abdominal organs herniate through the defect into the thoracic cavity. The main pathophysiology is respiratory distress and persistent pulmonary hypertension because of pulmonary hypoplasia caused by compression of the elevated organs. Recent progress in prenatal diagnosis and postnatal care has led to an increase in the survival rate of patients with CDH. However, some survivors experience mid- and long-term disabilities and complications requiring treatment and follow-up. In recent years, the establishment of clinical practice guidelines has been promoted in various medical fields to offer optimal medical care, with the goal of improvement of the disease' outcomes, thereby reducing medical costs, etc. Thus, to provide adequate medical care through standardization of treatment and elimination of disparities in clinical management, and to improve the survival rate and mid- and long-term prognosis of patients with CDH, we present here the clinical practice guidelines for postnatal management of CDH. These are based on the principles of evidence-based medicine using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. The recommendations are based on evidence and were determined after considering the balance among benefits and harm, patient and society preferences, and medical resources available for postnatal CDH treatment.

Update on the use of sildenafil in neonatal pulmonary hypertension: a narrative review of the history, current administration, and future directions

Pulmonary hypertension (PH) is a life-threatening syndrome in neonates and has multiple and varied etiologies. However, few clinical studies have systematically evaluated the treatment regimens for this population. Phosphodiesterase (PDE) inhibitors, such as milrinone, tadalafil, dipyridamole, and sildenafil, are the most important regulators of vascular relaxation in the normal pulmonary vascular transition after birth, and these agents are widely used in the treatment of PH. Sildenafil, a representative PDE-5 inhibitor, has an important role as a single mode of therapy. However, the lack of evidence from pharmacokinetic and clinical trials has limited the emergence of standardized treatment regimens for sildenafil. There are also differing opinions among researchers regarding the best route of sildenafil administration. Due to the interindividual variability in the neonatal population, it is worth selecting the most suitable route of sildenafil administration according to the specific conditions of the neonatal population. These may be evaluated using the oxygenation index (OI), pulmonary artery pressure, mean blood pressure, and the serological index. This article reviews the clinical data on the use of sildenafil, focusing on the current and promising alternative routes of administration, which may affect subsequent clinical research in term and preterm neonates.

Persistent pulmonary hypertension of the newborn

Persistent pulmonary hypertension of the newborn (PPHN) is a significant clinical problem characterized by refractory and severe hypoxemia secondary to elevated pulmonary vascular resistance resulting in right-to-left extrapulmonary shunting of deoxygenated blood. PPHN is associated with diverse cardiopulmonary disorders and a high early mortality rate for infants with severe PPHN. Surviving infants with PPHN have an increased risk of long-term morbidities. PPHN physiology can be categorized by (1) maladaptation: pulmonary vessels have normal structure and number but have abnormal vasoreactivity; (2) excessive muscularization: increased smooth muscle cell thickness and increased distal extension of muscle to vessels that are usually not muscularized; and (3) underdevelopment: lung hypoplasia associated with decreased pulmonary artery number. Treatment involves adequate lung recruitment, optimization of cardiac output and left ventricular function, and pulmonary vasodilators such as inhaled nitric oxide. Infants who fail to respond to conventional therapy should be evaluated for lethal lung disorders including alveolar-capillary dysplasia, T-box transcription factor 4 gene, thyroid transcription factor-1, ATP-binding cassette A3 gene, and surfactant protein diseases.

Oral drugs used to treat persistent pulmonary hypertension of the newborn

Introduction:Persistent Pulmonary Hypertension of the Newborn (PPHN) is a life-threatening neonatal condition, mostly treated with inhaled nitric oxide (iNO), intravenous prostaglandins, oral bosentan, sildenafil and tadalafil. However, the utility of non-oral agents is limited in PPHN for their side effects and inconvenient deliveries. Therefore, oral agents such as bosentan, sildenafil and tadalafil are becoming appealing for their satisfactory efficacy, easy mode of administration and acceptable side effects. Areas covered: We conducted a comprehensive search on Pubmed, Scopus, Web of Sciences concerning the use of bosentan, sildenafil and tadalafil to treat PPHN and summarized their efficacy, safety and pharmacokinetics. Expert opinion: Current randomized controlled trials (RCTs) have demonstrated the favorable responses and tolerable side effects of bosentan and sildenafil. Nevertheless, those RCTs are small and only one study has described the pharmacokinetics of sildenafil in neonates. Accordingly, bosentan, sildenafil and tadalafil remain off-label in clinical use. More well-designed RCTs with large samples and long-term follow-up and pharmacometrics studies are needed to demonstrate the efficacy, safety and pharmacokinetics of bosentan, sildenafil and tadalafil in PPHN.

Safety and effect of sildenafil on treating paediatric pulmonary arterial hypertension: a meta-analysis on the randomised controlled trials

BACKGROUND

Efficacy of sildenafil in treating paediatric pulmonary arterial hypertension is controversial. This systematic review aimed to explore the safety and effect of sildenafil on treating paediatric pulmonary arterial hypertension (PAH) through meta-analysis.

METHODS AND RESULTS

In this study, the electronic databases, including the Cochran Library database, EMBASE, and MEDLINE were systemically retrieved to identify the related randomised controlled trials (RCTs). Two reviewers had independently completed study selection, data collection, and assessment of the bias risk. Amongst 938 articles researched according to our retrieval strategy, 15 papers that involved 673 cases had been screened. Relative to control group, the sildenafil group had markedly reduced mortality (RR = 0.25, 95% CI: 0.12-0.51; p < 0.0001), but difference within the mortality was not statistically significant between high- and low-dose sildenafil groups (p = 0.152). Nonetheless, difference of the mean pulmonary arterial pressure between sildenafil as well as control group was of no statistical significance. Differences in the length of hospital stay and the incidences of pulmonary hypertensive crisis between children with PAH and controls were of no statistical significance. However, the summary estimate favoured that sildenafil reduced the duration of mechanical ventilation time, as well as the length of ICU stay and inotropic support.

CONCLUSIONS

Sildenafil therapy reduces the mortality of PAH patients, but its effects on the haemodynamic outcomes and other clinical outcomes are still unclear.

Congenital diaphragmatic hernia: current management strategies from antenatal diagnosis to long-term follow-up

Congenital diaphragmatic hernia (CDH) is a developmental birth defect consisting of a diaphragmatic defect and abnormal lung development. CDH complicates 2.3-2.8 per 10,000 live births. Despite efforts to standardize clinical practice, management of CDH remains challenging. Frequent re-evaluation of clinical practices in CDH reveals that management of CDH is evolving from one of postnatal stabilization to prenatal optimization. Translational research reveals promising avenues for in utero therapeutic intervention, including fetoscopic endoluminal tracheal occlusion. These remain highly experimental and demand improved antenatal diagnostics. Timely diagnosis of CDH and identification of severely affected fetuses allow time for delivery planning or in utero therapeutics. Optimal perinatal care and surgical treatment strategies are highly debated. Improved CDH mortality rates have placed increased emphasis on identifying and monitoring the long-term sequelae of disease throughout childhood and into adulthood. We review the current management strategies for CDH, highlighting where progress has been made, and where future developments have the potential to revolutionize care in this vulnerable patient population.

Prophylactic Sildenafil in Preterm Infants at Risk of Bronchopulmonary Dysplasia: A Pilot Randomized, Double-Blinded, Placebo-Controlled Trial

BACKGROUND

Bronchopulmonary dysplasia (BPD) is the need for oxygen therapy at 36 weeks postmenstrual age (PMA). Sildenafil has been shown to enhance the lung alveolarization and vascularization in newborn animal models after lung injury and has possible therapeutic potential for the prevention of BPD.

OBJECTIVE

To perform a proof-of-concept, Phase II, pilot randomized, double-blind, clinical trial to study the efficacy of sildenafil in preventing BPD, in postnatal (< 24 h), extremely and very preterm infants.

METHODS

This Phase II, pilot randomized, double-blind, clinical trial was conducted in the Neonatal Intensive Care Unit of Women's Wellness and Research Center, Doha, Qatar during 2012-2014. Infants of 24^0/7-29^6/7 weeks' gestation were eligible if they needed respiratory or oxygen support ≥ 25% at randomization, and if they were at a postnatal age of < 24 h at randomization. Forty preterm infants were randomly assigned to receive off-label oral sildenafil (0.5 mg/kg every 6 h) or a placebo solution, for one week. The primary endpoints were the incidence of BPD and death at 36 weeks PMA, and the side effects. Secondary outcomes included the incidence of BPD and the respiratory support at day 28 of life, duration of oxygen use, fraction of inspired oxygen use at 36 weeks and 28 days of life, duration of hospitalization, and the incidence of significant retinopathy of prematurity, severe intraventricular hemorrhage, periventricular leukomalacia, necrotizing enterocolitis, patent ductus arteriosus, and late sepsis.

RESULTS

No significant differences were observed between the sildenafil and placebo study groups in mortality at 36 weeks PMA (10% vs 20%, p = 1), respiratory support at 36 weeks (30% vs 25%, p = 0.57), and side effects (0% vs 0%). For all other secondary outcomes, no significant differences were detected.

CONCLUSIONS

While not associated with side effects, off-label oral sildenafil did not demonstrate benefits in the prevention of BPD or death in the extreme and very preterm infants. Future studies of dosing and efficacy that target different regimens of sildenafil are warranted before sildenafil is recommended for the prevention of BPD.

Pharmacokinetic modeling of intravenous sildenafil in newborns with congenital diaphragmatic hernia

PURPOSE

We developed a pharmacokinetic model of intravenous sildenafil in newborns with congenital diaphragmatic hernia (CDH) to achieve a target plasma concentration of over 50 μg/l.

METHODS

Twenty-three CDH newborns with pulmonary hypertension (64 blood samples) received intravenous sildenafil. Patients received a loading dose of 0.35 mg/kg (IQR 0.16 mg/kg) for 3 h, followed by a continuous infusion of 1.5 mg/kg/day (IQR 0.1 mg/kg/day). For model development, non-linear mixed modeling was used. Inter-individual variability (IIV) and inter-occasion variability were tested. Demographic and laboratory parameters were evaluated as covariates. Normalized prediction distribution errors (NPDE) and visual predictive check (VPC) were used for model validation.

RESULTS

A two-compartment disposition model of sildenafil and a one-compartment disposition model of desmethyl sildenafil (DMS) was observed with IIV in sildenafil and DMS clearance and volume of distribution of sildenafil. NPDE and VPC revealed adequate predictability. Only postnatal age increased sildenafil clearance. This was partly compensated by a higher DMS concentration, which also has a therapeutic effect. In this small group of patients, sildenafil was tolerated well.

CONCLUSIONS

This model for sildenafil in CDH patients shows that concentration-targeted sildenafil dosing of 0.4 mg/kg in 3 h, followed by 1.6 mg/kg/day continuous infusion achieves appropriate sildenafil plasma levels.

Effect of early adjunctive use of oral sildenafil and inhaled nitric oxide on the outcome of pulmonary hypertension in newborn infants. A feasibility study

INTRODUCTION

Inhaled nitric oxide (iNO) is the standard therapy for infants with persistent pulmonary hypertension of the newborn (PPHN). Recently, sildenafil has been evaluated as an alternative or adjunctive pulmonary vasodilator.

OBJECTIVE

To assess the effectiveness of adding sildenafil as an early adjunctive therapy together with iNO when treating newborns with PPHN and/or hypoxemic respiratory failure.

METHODS

This is a randomized placebo trial on newborns with gestational age > 34 weeks, postnatal age < 48 hours, and diagnosed with PPHN (oxygen index (OI) ≥ 20). Newborns were randomized to two groups: Group A- received oral sildenafil and iNO, and group B- received placebo and iNO. Initial and follow up echocardiography were performed over 14 days period.

RESULTS

A total of 24 newborns were recruited; 13 of them received sildenafil in addition to iNO and 11 received iNO and placebo. The most common causes of PPHN were meconium aspiration syndrome, pneumonia, and RDS. At the starting point, OI was marginally higher in the intervention group without statistical significance (29 vs 28). There were no differences between the two groups regarding surfactant administration, incidence of pneumothoraces, and the underlying causes of PPHN. Sildenafil or placebo treatment started within 12 hours after starting iNO (8 vs 6 hours).

CONCLUSION

Early use of oral sildenafil next to iNO in cases of PPHN was tolerated well by newborns and it did not show significant adverse effects. Further studies with a larger sample size is needed to assess its effecacy.

Sildenafil for pulmonary hypertension in neonates

BACKGROUND

Persistent pulmonary hypertension in the neonate (PPHN) is associated with high mortality. Currently, the therapeutic mainstay for PPHN consists of assisted ventilation and administration of inhaled nitric oxide (iNO). However, nitric oxide is costly, and its use may not be appropriate in resource-poor settings. Approximately 30% of patients fail to respond to iNO. High concentrations of phosphodiesterases in the pulmonary vasculature have led to the use of phosphodiesterase inhibitors such as sildenafil or milrinone.

OBJECTIVES

To assess the efficacy and safety of sildenafil for treatment of pulmonary hypertension in neonates.

SEARCH METHODS

We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL; 2017, Issue 3), MEDLINE via PubMed (1966 to 18 April 2017), Embase (1980 to 18 April 2017), and the Cumulative Index to Nursing and Allied Health Literature (CINAHL; 1982 to 18 April 2017). We searched clinical trials databases, conference proceedings, and reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials.

SELECTION CRITERIA

We included randomised and quasi-randomised controlled trials of sildenafil compared with placebo or other pulmonary vasodilators, irrespective of dose, route, and duration of administration, in neonates with pulmonary hypertension, if investigators reported any of the prespecified outcomes.

DATA COLLECTION AND ANALYSIS

We assessed the methodological quality of trials regarding how bias was minimised at study entry, during study intervention, and at outcomes measurement. We extracted data on relevant outcomes; we estimated the effect size and reported it as risk ratio (RR), risk difference (RD), or mean difference (MD), as appropriate. We applied the I² test of heterogeneity and used GRADE to assess the quality of evidence.

MAIN RESULTS

For this update, we identified two additional studies, for a total of five eligible trials that enrolled 166 infants. The methodological quality of these studies ranged from low to high risk of bias. Three studies were performed in resource-limited settings, where iNO and high-frequency ventilation were not available at the time of the study. One study compared sildenafil versus active controls, and another study evaluated sildenafil as adjuvant therapy to iNO. When comparing sildenafil with placebo, investigators noted significant reduction in mortality in the sildenafil alone group (three studies, 77 participants; typical RR 0.20, 95% confidence interval (CI) 0.07 to 0.56; I² = 0% - none; typical RR -0.36, 95% CI -0.53 to -0.18; number needed to treat for an additional beneficial outcome 3, 95% CI 2 to 6; I² = 39% - low). Trials reported no significant differences in mortality upon comparison of the sildenafil group versus the active control group (one study, 65 participants; typical RR 0.55, 95% CI 0.05 to 5.75), or when iNO was administered to both groups (one study, 24 participants; typical RR 1.27, 95% CI 0.26 to 6.28). Physiological parameters of oxygenation (oxygenation index, partial pressure of oxygen in arterial blood (PaO₂)) suggested steady improvement after the first dose of sildenafil. None of the included trials identified any clinically important side effects. We rated the quality of evidence as low to very low owing to imprecision related to small sample size and unclear methodological features.

AUTHORS' CONCLUSIONS

Sildenafil used for treatment of pulmonary hypertension has potential for reducing mortality and improving oxygenation in neonates, especially in resource-limited settings where iNO is not available. However, large-scale randomised trials comparing sildenafil versus active controls (other pulmonary vasodilators) and providing follow-up for survivors are needed to assess the comparative effectiveness and long-term safety of sildenafil versus other pulmonary vasodilators.

Pulmonary Hypertension Therapy and a Systematic Review of Efficacy and Safety of PDE-5 Inhibitors

Pulmonary hypertension (PH) is a syndrome that is of growing concern to pediatricians worldwide. Recent data led to concerns about the safety of phosphodiesterase type 5 (PDE5) inhibitors in children and a US Food and Drug Administration safety advisory. Our objective is to provide insight into therapies for PH in children and to systematically review the comparative effectiveness and safety of PDE5 inhibitors in the management of pediatric patients with PH. We searched the following databases through February 2015: Medline, Embase, SCOPUS, and the Cochrane Central Register of Controlled Trials. We included studies that examined PDE5 inhibitor use in children with PH. Allowed comparators were either no medication or other classes of medication for management of PH. Study inclusion was via a 2-stage process with 2 reviewers and a predesigned form. Of 1270 papers identified by the literature search, 21 were included: 8 randomized controlled trials and 13 observational studies (9 retrospective, 4 prospective). There is strong evidence that PDE5 inhibitor use improves echocardiography measurements, cardiac catheterization parameters, and oxygenation compared with baseline or placebo in pediatric patients with PH. Evidence suggests that low- and moderate-dose sildenafil are safe regimens for children. There are a relatively small number of randomized controlled trials that address use of PDE5 inhibitors in pediatric patients with PH. PDE5 inhibitors are effective agents for cardiovascular and oxygenation end points in pediatric PH and important components of a multimodal pharmacotherapeutic approach to this growing challenge. Additional studies are needed to define optimal PH therapy in childhood.

Sildenafil in pediatric pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a life-threatening disease of varied etiologies. Although PAH has no curative treatment, a greater understanding of pathophysiology, technological advances resulting in early diagnosis, and the availability of several newer drugs have improved the outlook for patients with PAH. Sildenafil is one of the therapeutic agents used extensively in the treatment of PAH in children, as an off-label drug. In 2012, the United States Food and Drug Administration (USFDA) issued a warning regarding the of use high-dose sildenafil in children with PAH. This has led to a peculiar situation where there is a paucity of approved therapies for the management of PAH in children and the use of the most extensively used drug being discouraged by the regulator. This article provides a review of the use of sildenafil in the treatment of PAH in children.

Standardized Postnatal Management of Infants with Congenital Diaphragmatic Hernia in Europe: The CDH EURO Consortium Consensus - 2015 Update

In 2010, the congenital diaphragmatic hernia (CDH) EURO Consortium published a standardized neonatal treatment protocol. Five years later, the number of participating centers has been raised from 13 to 22. In this article the relevant literature is updated, and consensus has been reached between the members of the CDH EURO Consortium. Key updated recommendations are: (1) planned delivery after a gestational age of 39 weeks in a high-volume tertiary center; (2) neuromuscular blocking agents to be avoided during initial treatment in the delivery room; (3) adapt treatment to reach a preductal saturation of between 80 and 95% and postductal saturation >70%; (4) target PaCO2 to be between 50 and 70 mm Hg; (5) conventional mechanical ventilation to be the optimal initial ventilation strategy, and (6) intravenous sildenafil to be considered in CDH patients with severe pulmonary hypertension. This article represents the current opinion of all consortium members in Europe for the optimal neonatal treatment of CDH.

Oral sildenafil and inhaled iloprost in the treatment of pulmonary hypertension of the newborn

OBJECTIVE

This study was performed to examine the effectiveness and safety of oral sildenafil and inhaled iloprost in term newborns with persistent pulmonary hypertension of the newborn (PPHN).

PATIENTS AND METHODS

Oral sildenafil and inhaled iloprost were administered to 27 and 20 neonates, respectively, for treatment of persistent pulmonary hypertension. All patients were term infants at 37 gestational weeks or older. In the sildenafil group, 14 patients had meconium aspiration syndrome, 8 had asphyxia (hypoxic ischemic encephalopathy stages II and III), 3 had congenital pneumonia, 1 had transient tachypnea, and 1 had idiopathic PPHN. In the iloprost group, 9 patients had meconium aspiration syndrome, 7 had asphyxia (hypoxic ischemic encephalopathy stages II and III), 3 had congenital pneumonia, and 1 had transient tachypnea. Sildenafil citrate was administered via an oral feeding tube. Iloprost was administered endotracheally to patients on mechanical ventilation using a jet nebulizer.

RESULTS

Iloprost appeared to be more effective than sildenafil in the treatment of PPHN with regard to time to adequate clinical response, ventilatory parameters, duration of drug administration, duration of mechanical ventilation, duration of return to normal values of respiratory failure indices, use of MgSO4 as a second vasodilator and requirement for support with inotropic agents. We observed no side effects on blood pressure or homeostasis in any of the patients in the iloprost group. Systemic hypotension was significantly elevated in the sildenafil group. Four and three infants died of PPHN in the sildenafil and iloprost groups, respectively. Pulmonary systolic arterial pressure decreased to normal levels in the remaining 40 patients, and they were discharged from hospital.

CONCLUSION

We suggested that inhaled iloprost may be a safe and effective treatment choice in newborn infants with persistent pulmonary hypertension. In cases where treatment with inhaled iloprost, ECMO or INO is not possible, oral sildenafil can be an alternative therapy option in the treatment of PPHN.

Is sildenafil an effective therapy in the management of persistent pulmonary hypertension?

Persistent pulmonary hypertension of the newborn (PPHN) is a life-threatening neonatal pathology resulting from poor hemodynamic and respiratory transition to extra uterine life. Inhaled nitric oxide (iNO) is a current, commonly used treatment of PPHN. However, iNO is not available therapy in many developing countries and around 50% of infants with PPHN do not respond to iNO therapy. Sildenafil is a phosphodiesterase inhibitor type 5 (PDE5) that has been shown to selectively reduce pulmonary vascular resistance in both animal models and adult humans. Recent studies have found that in PPHN, administration of Sildenafil was associated with a significant increase in the oxygenation and a reduction in mortality with no clinically important side effects.