Management of Pulmonary Arterial Hypertension in the Neonatal Unit

Targeted Therapy for Pulmonary Hypertension in Premature Infants

Pulmonary hypertension (PH) is common in premature infants with bronchopulmonary dysplasia (BPD) and is associated with significant mortality. Despite expert consensus suggesting the use of targeted therapies such as phosphodiesterase inhibitors, endothelin receptor antagonists, and prostanoids, there is little data on safety and outcomes in infants with BPD-associated PH (BPD-PH) treated with these medications. We sought to describe the pharmacologic management of BPD-PH and to report outcomes at our institution. Premature infants with BPD-PH born between 2005 and 2016 were included. Follow-up data were obtained through January 2020. A total of 101 patients (61 male, 40 female) were included. Of these, 99 (98.0%) patients were treated with sildenafil, 13 (12.9%) with bosentan, 35 (34.7%) with inhaled iloprost, 12 (11.9%) with intravenous epoprostenol, and nine (8.9%) with subcutaneous treprostinil. A total of 33 (32.7%) patients died during the study period and 10 (9.9%) were secondary to severe to pulmonary hypertension. Of the surviving patients, 57 (83.8%) had follow-up data at a median of 5.1 (range 0.38-12.65) years and 44 (77.2%) were weaned off PH medications at a median 2.0 (range 0-8) years. Mortality for BPD-PH remains high mostly due to co-morbid conditions. However, for those patients that survive to discharge, PH therapies can frequently be discontinued in the first few years of life.

Adjunctive treatments in pediatric acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) is a devastating process that involves pulmonary inflammation, alveolar damage and hypoxemic respiratory failure. Although advances in management approaches over the past two decades have resulted in significantly improved outcomes, death from pediatric ARDS may still occur in up to 35% of patients. While invasive mechanical ventilation is an essential component of ARDS management, various adjuncts have been utilized as treatment for these patients. However, evidence-based data in infants and children in this area are lacking. In this article, the authors review the available evidence supporting (or not supporting) the use of non-ventilatory adjunctive strategies in the management of pediatric ARDS, including prone positioning, pulmonary vasodilators, β-agonists, steroids and surfactant.

Guidelines for Rational and Cost-Effective Use of iNO Therapy in Term and Preterm Infants

Inhaled nitric oxide (iNO) is an effective but costly therapy for infants with hypoxemic respiratory failure. The approved and solidly evidence-based indication is for treatment of late preterm and term infants with persistent pulmonary hypertension of the newborn (PPHN); however, off-label use of iNO has become widespread. Although iNO treatment of infants with congenital diaphragmatic hernia constitutes one of the approved indications, available evidence from randomized trials suggests marginal if any efficacy. Rescue therapy in preterm infants with severe respiratory failure has been studied extensively and is not supported by data from a number of controlled trials. Such use is widespread, but should be discouraged. There may be a subgroup of such infants with pulmonary hypoplasia and documented PPHN who may benefit from this treatment, but the data are limited. Several studies have examined the use of iNO for prevention of chronic lung disease with inconsistent results. This promising application requires more study before it can be recommended. There may be a role of iNO in treating infants with pulmonary hypertension complicating severe bronchopulmonary dysplasia, but there are limited data on long term outcomes. Alternate therapies such as sildenafil may be beneficial in this specific population as well as in other causes of pulmonary hypertension. Rational use of this expensive treatment will maximize cost:benefit and avoid potential exposure to unknown adverse effects not balanced by documentable benefits.

Persistent pulmonary hypertension of the newborn: recent advances in pathophysiology and treatment

OBJECTIVES

Although recognized for decades, little is known about the etiology, physiopathology, and prevention of persistent pulmonary hypertension of the newborn (PPHN), and its treatment remains a major challenge for neonatologists. In this review, the clinical features and physiopathology of the syndrome will be addressed, as well as its general and specific treatments.

DATA SOURCE

A review was carried out in PubMed, Cochrane Library, and MRei consult databases, searching for articles related to the syndrome and published between 1995 and 2011.

DATA SYNTHESIS

Risk factors and the physiopathological mechanisms of the syndrome are discussed. The clinical presentation depends on the different factors involved. These are related to the etiology and physiopathology of the different forms of the disease. In addition to the measures used to allow for the decrease in pulmonary vascular resistance after birth, in some instances pulmonary vasodilators will be required. Although inhaled nitric oxide has proved effective, other vasodilators have been recently used, but clinical evidence is still lacking to demonstrate their benefits in the treatment of PPHN.

CONCLUSIONS

Despite recent technological advances and new physiopathological knowledge of this disease, mortality associated with PPHN remains at 10%. More clinical research and evidence-based experimental results are needed to prevent, treat, and reduce the morbidity/mortality associated with this neonatal syndrome.

Sildenafil citrate, bronchopulmonary dysplasia and disordered pulmonary gas exchange: any benefits?

OBJECTIVE

The objective of this study is to determine the effects that sildenafil citrate has on gas exchange in infants with bronchopulmonary dysplasia (BPD)-associated pulmonary hypertension (PH).

STUDY DESIGN

A retrospective review was performed from 2005 to 2009. Infants treated with sildenafil citrate for greater than 48  h were included. Standard patient data was collected, including echocardiogram, inspired oxygen and systemic blood pressure, before and during administration of sildenafil citrate.

RESULT

Sildenafil citrate was used in 21 preterm infants with BPD-associated PH. A significant reduction in estimated right ventricular peak systolic pressure was seen after initiation of sildenafil citrate, with the majority of infants showing no improvement in gas exchange at 48  h of treatment. Four infants died during treatment.

CONCLUSION

Sildenafil citrate reduced estimated pulmonary artery pressures, but this reduction was not reflected in improved gas exchange within the first 48  h.