Neonatal pulmonary hypertension after severe early-onset fetal growth restriction: post hoc reflections on the Dutch STRIDER study

The aim was to reflect on the unexpected finding of persistent pulmonary hypertension of the neonate (PPHN) and pulmonary hypertension in infants born within the Dutch STRIDER trial, its definition and possible pathophysiological mechanisms. The trial randomly assigned pregnant women with severe early-onset fetal growth restriction to sildenafil 25 mg three times a day versus placebo. Sildenafil use did not reduce perinatal mortality and morbidity, but did result in a higher rate of neonatal pulmonary hypertension (PH). The current paper reflects on the used definition, prevalence, and possible pathophysiology of the data on pulmonary hypertension. Twenty infants were diagnosed with pulmonary hypertension (12% of 163 live born infants). Of these, 16 infants had PPHN shortly after birth, and four had pulmonary hypertension associated with sepsis or bronchopulmonary dysplasia. Four infants with PPHN in the early neonatal period subsequently developed pulmonary hypertension associated with bronchopulmonary dysplasia in later life. Infants with pulmonary hypertension were at lower gestational age at delivery, had a lower birth weight and a higher rate of neonatal co-morbidity. The infants in the sildenafil group showed a significant increase in pulmonary hypertension compared to the placebo group (relative risk 3.67; 95% confidence interval 1.28 to 10.51, P = 0.02).Conclusion: Pulmonary hypertension occurred more frequent among infants of mothers allocated to antenatal sildenafil compared with placebo. A possible pathophysiological mechanism could be a “rebound” vasoconstriction after cessation of sildenafil. Additional studies and data are necessary to understand the mechanism of action. What is Known:• In the Dutch STRIDER trial, persistent pulmonary hypertension in the neonate (PPHN) was more frequent among infants after antenatal sildenafil exposure versus placebo. What is New:• The current analysis focuses on the distinction between PPHN and pulmonary hypertension associated with sepsis or bronchopulmonary dysplasia and on timing of diagnosis and aims to identify the infants at risk for developing pulmonary hypertension.• The diagnosis pulmonary hypertension is complex, especially in infants born after severe early-onset fetal growth restriction. The research field could benefit from an unambiguous consensus definition and standardized screening in infants at risk is proposed.

Efficacy and safety of endotracheal instillation of iloprost for persistent pulmonary hypertension of the newborn

Objective: To determine the efficacy and safety of endotracheal instillation of iloprost as a rescue therapy for persistent pulmonary hypertension of the newborn. Methods: Neonates diagnosed with persistent pulmonary hypertension who were unresponsive to standard treatment protocol applied for persistent pulmonary hypertension in our unit, and who were being followed up with mechanical ventilation, were included in the study. Iloprost was instilled endotracheally as a rescue treatment. Systolic pulmonary artery pressure, oxygen saturation index, mean airway pressure, fraction of inspired oxygen, preductal and postductal venous oxygen saturation, heart rate, and blood pressure were recorded before and after 30 minutes of endotracheal iloprost instillation. Adverse events after endotracheal iloprost were recorded. Results: Twenty neonates were included. The median gestational age and birth weight were found to be 37 (30.5-38) weeks and 2975 (2125-3437.5) grams, respectively. When compared to the period before endotracheal iloprost instillation, systolic pulmonary artery pressure, oxygen saturation index, mean airway pressure, and fraction of inspired oxygen values significantly decreased (p < 0.001, p < 0.001, p = 0.021, p = 0.001, respectively), whereas preductal and postductal oxygen saturation values significantly increased 30 minutes after the endotracheal iloprost instillation (p = 0.002, p < 0.001, respectively). There were no significant differences in heart rate and blood pressure values before and after the iloprost administration. No adverse events were observed. Conclusion: Endotracheal instillation of iloprost was found to be an effective and safe therapy for persistent pulmonary hypertension unresponsive to conventional treatment.

Evidence-based guidelines for acute stabilization and management of neonates with persistent pulmonary hypertension of the newborn

Persistent pulmonary hypertension of the newborn, or PPHN, represents a challenging condition associated with high morbidity and mortality. Management is complicated by complex pathophysiology and limited neonatal specific evidence-based literature, leading to a lack of universal contemporary clinical guidelines for the care of these patients. To address this need and to provide consistent high-quality clinical care for this challenging population in our neonatal intensive care unit, we sought to develop a comprehensive clinical guideline for the acute stabilization and management of neonates with PPHN. Utilizing cross-disciplinary expertise and incorporating an extensive literature search to guide best practice, we present an approachable, pragmatic, and clinically relevant guide for the bedside management of acute PPHN.

Title: Clinical Profile of Persistent Pulmonary Hypertension in Neonates with Role of Sildenafil in its Outcome: Rural India NICU Experience

Background: Persistent pulmonary hypertension of newborn (PPHN) result from failure of normal fall in pulmonary vascular resistance at or shortly after birth. It is associated with high mortality and morbidity. Objectives: To estimate incidence, risk factors; and outcome within limited resources – conventional ventilation, sildenafil, dobutamine and milrinone therapy. Methods: This prospective study was carried out on cases of PPHN admitted between March 2017 to August 2018. PPHN was suspected clinically, and then confirmed by echocardiography. Results: Out of 2811 inborn live births 12 (0.43%) developed PPHN. Out of total 942 NICU admissions, PPHN was diagnosed in 40(4.2%). 32 (80%) were full term, 6 (15%) were late preterm and 2(5%) were post term neonates. 25(62.5%) were male. Major etiological factors were asphyxia 19(47.5%), EOS (early onset sepsis) 18(45%) and MAS (meconium aspiration syndrome) 12(30%). 20(50%) responded to oral sildenafil and dobutamine therapy, 6 more responded with addition of milrinone. The overall survival rate was 26(65%) and poor outcome in 14 (35%) in our study. Median duration of respiratory support was 1.5(1 – 6) days in those with poor outcome and 6(4 – 7) in those survived. Duration of hospital stay was 1.5(1 – 6) days in poor outcome and 17(13 – 22) in those survived. Conclusions: Asphyxia, EOS and MAS are common causes of PPHN. Severity of respiratory distress on admission is correlated with mortality rather than etiological factors. Conventional ventilation, dobutamine, sildenafil and milrinone therapy are mainstay of treatment of PPHN cases in resource limited settings, and helps to reduce mortality to some extent.

Case Report: Persistent Pulmonary Hypertension of the Newborn and Narrowing of the Ductus Arteriosus After Topical Use of Non-Steroidal Anti-Inflammatory During Pregnancy

Background: The use of non-steroidal anti-inflammatory drugs (NSAIDs) during the third trimester of pregnancy can cause premature constriction of the ductus arteriosus. This report describes a case of in utero narrowing of the ductus arteriosus (DA) diagnosed postnatally in a baby with Persistent Pulmonary Hypertension of the Newborn (PPHN), after maternal use of Diclofenac-Epolamine 140 mg patch during the second and third trimester.Case Presentation: A fetal ultrasounds revealed an enlarged hypertrophic right ventricle at 32 weeks of gestation. Detailed questioning of the mother highlighted that topical Diclofenac (FLECTOR®) had been used at 26 and at 31 weeks of gestation. An echocardiography performed 8 h postnatally showed supra-systemic pulmonary hypertension, a restrictive ductus arteriosus and a dilated right ventricle. The newborn was treated by inhaled nitric oxide and oral Sildenafil and was discharged from hospital on day 24. He had a complete normalization of his pulmonary vascular resistance on day 48.Conclusion: This case illustrates the potential fetal and neonatal complications associated with maternal topical Diclofenac medication during pregnancy resulting in antenatal closure of the DA.

Efficacy of a combination of sildenafil and magnesium sulfate in the treatment of persistent pulmonary hypertension of the newborn, and its influence on hemodynamics

Purpose: To investigate the efficacy of the combined use of sildenafil and magnesium sulfate in the treatment of persistent pulmonary hypertension of the newborn (PPHN), and its influence on hemodynamics.Methods: A total of 174 children with persistent pulmonary hypertension who were treated in Ganzhou People’s Hospital, Ganzhou, China were selected and randomly assigned to joint group (JG) and control group (CG), with 87 patients in each group. The CG group received magnesium sulfate, while the JG group received sildenafil plus magnesium sulphate. The respiratory parameters of the children were analyzed using blood gas analyzer, while their hemodynamic indices were evaluated using color Doppler echocardiography. The levels of cytokines and inflammatory factors were determined by enzyme-linked immunosorbent assay (ELISA).Results: Time taken for symptom disappearance, oxygen therapy, and hospitalization period were shorter in JG than in CG (p < 0.05). Post-treatment, the respiratory parameters (PaO2, PaCO2, and SaO2) in both groups s improved, with lower levels of PaO2 and PaCO2, and a higher level of SaO2 in JG (p < 0.05). Following treatment, the levels of systemic vascular resistance (SVR), posterior pulmonary vascular resistance (PVR) and pulmonary artery pressure (PA) in JG were significantly reduced, relative to CG (p < 0.05). Similarly, the expression of endothelin -1 (ET-1), brain natriureticpeptide (BNP), and angiotensin 1 (ANG-1) improved, with lower levels of ET-1 and BNP, and a higher level of ANG-1 in JG (p < 0.05). There was post-treatment reduction as well in IL-6 and TNF-α, with lower levels in JG (p < 0.05). Patients in JG showed higher total treatment effectiveness and a lowerincidence of adverse reactions than those in CG (p < 0.05).Conclusion: The combined use of sildenafil and magnesium sulfate enhances the management of PPHN, ameliorates respiratory parameters, hemodynamics, and levels of cytokines and inflammatory factors. These findings provide evidence-based medical references for a new treatment strategy for PPHN.