Neonatal pulmonary hypertension: a physiologic approach to treatment

Risk factors and outcomes of persistent pulmonary hypertension of the newborn in neonatal intensive care unit of Al-minya university hospital in egypt

Background:

Persistent pulmonary hypertension of the newborn (PPHN) result from the failure of the normal fetal-to-neonatal circulatory transition is associated with substantial infant mortality and morbidity.

Objective:

To estimate the possible risk factors and assess the outcome of these cases.

Materials and Methods:

Prospective study was performed enrolling all full-term and post-term newborn admitted to the NICU from January 2009 to April 2012, All neonates were subjected to complete history and physical examination, laboratory data including a complete blood count, arterial blood gases, blood glucose, serum electrolytes, and blood culture to exclude sepsis. Cases with PPHN had a continuous pulse oximeter, blood pressure and electrocardiography monitoring. Chest X-ray and echocardiogarphy were carried out to verify shunt and exclude structural congenital heart disease.

Results:

Out of the studied 640 infants, 32 infants (5%) developed PPHN, Meconium aspiration, birth asphyxia, hyaline membrane diseases, neonatal septicemia, post-term birth being large for gestational age, cesarean section, maternal overweight, and diabetes mellitus were associated with an elevated risk for PPHN. All neonates treated with O₂, 10 neonates with Mg sulphate, 16 with oral sildenafil and 12 with mechanical ventilation. After 6 months follow-up, 12 (37.54%) improved and followed-up without sequelae, 4 (12.5%) developed some neurodevelopmental impairment, 8 (25%) died, 3 (9.3%) developed chronic lungs diseases, 2 (6.2%) developed hearing defects and another 3 (9.3%) missed follow-up.

Conclusion:

PPHN was found in 5% of the studied population. Meconium aspiration, birth asphyxia, neonatal septicemia, post-term were associated with an elevated risk for PPHN. As this is a unit based study, a comprehensive countrywide survey on PPHN in Egypt is recommended to determine any regional differences in disease incidence.

Etiology, diagnosis, and pharmacologic treatment of pediatric pulmonary hypertension

Major advances have been made in the understanding and treatment of pulmonary hypertension in the last few years. Without treatment (medication) for idiopathic pulmonary arterial hypertension, which is a rare and potentially fatal condition, the survival time is only about 3 years after diagnosis. However, if pulmonary hypertension is secondary to other causes such as congenital heart disease, it is possible to survive for 30 years or more without treatment. The condition can affect children at any age, from fetal life to adulthood. Patients with pulmonary hypertension can present to the respiratory pediatrician with unresponsive asthma, to the neurologist with faints, or to the general pediatrician with failure to thrive. Over the last few years there have been significant developments in the available therapy for managing this complicated disease. There is now a generally recognized ladder of long-term therapy for chronic pulmonary hypertension. Treatment can start with oxygen at home at night or even during the day. Next is the use of oral phosphodiesterase inhibitors, mostly type V, such as sildenafil, which enhance endogenous nitric oxide. More potent are the endothelin receptor antagonists and the most potent are the prostanoids, especially epoprostenol, which is given by constant intravenous infusion. In addition to interventional catheterization with atrial septostomy, these agents have improved the prognostic outlook. This article reviews the current knowledge about the etiology, investigation, and treatment of children with pulmonary hypertension in the clinical setting.

Treatment of pediatric pulmonary hypertension

Pulmonary hypertension was once thought to be a rare condition and only managed in specialized centers. Now however, with the advent of echocardiography, it is found in many clinical scenarios, in the neonate with chronic lung disease, in the acute setting in the intensive care unit, in connective tissue disease and in cardiology pre- and postoperatively. We have a better understanding of the pathological process and have a range of medication which is starting to be able to palliate this previously fatal condition. This review describes the areas that are known in this condition and those that are less familiar. The basic physiology behind pulmonary hypertension and pulmonary vascular disease is explained. The histopathologic process and the various diagnostic tools are described and are followed by the current and future therapy at our disposal.

Risk of persistent pulmonary hypertension of the neonate in twin-to-twin transfusion syndrome

BACKGROUND

Chronic twin-to-twin transfusion syndrome (TTTS) is a complication of monochorionic twin gestations and is associated with high perinatal mortality and increased neurological, cardiovascular and renal morbidity.

OBJECTIVE

To report the risk of severe persistent pulmonary hypertension of the newborn (PPHN) in TTTS and discuss the possible association between severe PPHN and TTTS.

METHODS

All cases of monochorionic twins with severe PPHN at birth admitted to our nursery between June 2002 and July 2006 were reviewed retrospectively. We compared the incidence of severe PPHN in monochorionic twins with and without TTTS. Severe PPHN was diagnosed according to clinical and ultrasound criteria when an infant with a structurally normal heart had (1) severe hypoxemia and (2) evidence of a right-to-left shunt on persistent ductus arteriosus or foramen ovale, requiring treatment with inhaled nitric oxide (iNO).

RESULTS

In a consecutive series of 73 twin pregnancies with TTTS, 4 of the 135 live-born twins (3%) were affected by severe PPHN. All reacted promptly to treatment with iNO. The incidence of severe PPHN in monochorionic twins without TTTS was 0% (0/161).

CONCLUSION

In view of the severe clinical course in PPHN and need for adequate and prompt treatment with iNO, perinatologists should be aware of the increased risk of severe PPHN in TTTS.

Management and therapeutic options in pediatric pulmonary hypertension

Idiopathic pulmonary arterial hypertension is a rare and potentially fatal condition. Without treatment, survival is only approximately 2.8 years from diagnosis. However, if the pulmonary hypertension is secondary to other causes, especially to congenital heart disease, it is possible to survive for 30 years or more without treatment. In recent years, remarkable progress has been made, risk factors have been identified and improved imaging techniques, including echocardiography, computer tomography and magnetic resonance imaging, are available. The condition can affect children at any age from fetal life through to adulthood. Patients can present to the respiratory pediatrician with unresponsive asthma, to the neurologist with faints or to the general pediatrician with failure to thrive. Over the last few years there have been significant developments in the available therapy for managing this complicated disease, which have improved the prognostic outlook, such as oral bosentan and sildenafil, intravenous epoprostenol and interventional catheterization with atrial septostomy. This article reviews the current knowledge about causation, investigation and treatment of children with pulmonary hypertension in the clinical setting.

Persistent pulmonary hypertension of the newborn: not a honeymoon anymore

Persistent pulmonary hypertension of the newborn is a disorder of transition to extrauterine life, in which the newly born baby cannot decrease the high pulmonary vascular resistance and low pulmonary blood flow, characteristic of the fetus, to that of a low pulmonary vascular resistance and high pulmonary blood flow necessary for postnatal survival. The syndrome primarily affects the neonate 34 weeks postmenstrual age and greater. The article will summarize the latest understanding of the pathophysiology and review innovations in management strategies that have greatly decreased mortality and morbidity since the advent of neonatal intensive care units.