What is the course of Persistent Fetal Circulation (PFC) or Neonatal Persistent Fetal Circulation (PFC)?

From the Guidelines

The course of Persistent Pulmonary Hypertension of the Newborn (PPHN) is characterized by increased pulmonary vascular resistance, right-to-left shunting, and severe hypoxemia, with a high morbidity and mortality rate of approximately 10% to 20%. The condition is frequently associated with pulmonary parenchymal abnormalities, including meconium aspiration, pneumonia, sepsis, lung hypoplasia, and alveolar capillary dysplasia 1. The mechanisms responsible for achieving a normal fall in pulmonary vascular resistance (PVR) at birth are poorly understood, but the interaction between healthy endothelial and smooth muscle cells produces a balance between relaxation and contraction favoring relaxation due to release of endothelium-derived nitric oxide (NO) 1.

The treatment of PPHN typically involves the use of inhaled NO, which has been shown to improve oxygenation and reduce the need for extracorporeal membrane oxygenation (ECMO) 1. Other treatment strategies, such as high frequency ventilation and lung recruitment strategies, may also be useful in enhancing the efficacy of inhaled NO 1. ECMO may be necessary for neonates with refractory hypoxemia, although it may be associated with significant morbidity, including hemorrhagic, neurologic, and other complications 1.

Key points to consider in the course of PPHN include:

• The condition is multifactorial in origin, with various underlying defects contributing to the failure to adapt to extrauterine life 1
• The primary abnormality most likely varies with various risk factors, similar to what is postulated for various other forms of pulmonary arterial hypertension (PAH) 1
• Increased circulating endothelin-1 levels have been reported after birth in these neonates, suggesting a potential role for endothelin in the pathophysiology of PPHN 1
• The rationale for treating with inhaled NO and possibly a phosphodiesterase-5 inhibitor, such as sildenafil, is due to an absolute or relative lack of endogenous NO 1.

Overall, the course of PPHN is complex and multifactorial, requiring a comprehensive treatment approach that takes into account the underlying pathophysiology and the individual needs of the neonate. The use of inhaled NO, high frequency ventilation, and ECMO, as well as other treatment strategies, may be necessary to improve outcomes and reduce morbidity and mortality in neonates with PPHN.

From the Research

Course of PFCN

There is no information available on the course of PFCN in the provided studies.

Related Information on PPHN

However, the studies do provide information on the course and treatment of Persistent Pulmonary Hypertension of the Newborn (PPHN), which may be relevant:

• The diagnosis of PPHN is made by characteristic lability in oxygenation of the infant, echocardiographic evidence of increased pulmonary pressure, with demonstrable shunts across the ductus arteriosus or foramen ovale, and the absence of cyanotic heart disease lesions 2.
• Management of PPHN includes treatment of underlying causes, sedation and analgesia, maintenance of adequate systemic blood pressure, and ventilator and pharmacologic measures to increase pulmonary vasodilatation, decrease pulmonary vascular resistance, increase blood and tissue oxygenation, and normalize blood pH 2.
• Inhaled nitric oxide (iNO) has been shown to be an effective treatment for PPHN, but nearly 40% of infants are iNO resistant 3.
• Other treatment options for PPHN include sildenafil, prostaglandins, milrinone, and bosentan, which have shown potential beneficial effects on newborns with PPHN 4, 3.
• A systematic review and network meta-analysis found that a combination of iNO and sildenafil was the most effective treatment for PPHN, and that sildenafil combined with milrinone was a suitable alternative if iNO was not available 5.

Key Points

• PPHN is a serious and potentially fatal condition characterized by sustained elevation of pulmonary vascular resistance at birth.
• The diagnosis of PPHN is made by characteristic lability in oxygenation of the infant, echocardiographic evidence of increased pulmonary pressure, and the absence of cyanotic heart disease lesions.
• Management of PPHN includes treatment of underlying causes, sedation and analgesia, maintenance of adequate systemic blood pressure, and ventilator and pharmacologic measures to increase pulmonary vasodilatation.
• iNO is an effective treatment for PPHN, but other options such as sildenafil, prostaglandins, milrinone, and bosentan may be used in iNO-resistant cases or if iNO is not available.