What is persistent pulmonary hypertension in the neonate (PPHN)?
PPHN refers to a serious breathing problem in newborns. It usually happens in full-term babies or babies who were born at 34 weeks or more. These babies often have other types of breathing conditions.
This condition may also be known as persistent pulmonary hypertension in the newborn and/or persistent fetal circulation syndrome.
How does persistent pulmonary hypertension in the neonate (PPHN) occur?
During pregnancy, the baby gets its oxygen from its mother and the placenta. Very little blood goes to the lungs because the blood vessels in the baby’s lungs are mostly closed. The blood vessels only open after birth when the baby takes his or her first breaths. The vessels then allow blood to travel to the lungs to get oxygen. PPHN happens when the blood vessels do not open up enough, which means that there is a limit on how much oxygen is sent to the brain and organs. This is why PPHN is so dangerous.
What are the risk factors for persistent pulmonary hypertension in the neonate (PPHN) ?
Although the cause is unknown, certain factors increase the infant’s risk of developing PPHN. These factors include:
- Meconium aspiration: This happens when the baby breathes in its own sticky poop (meconium).
- Respiratory distress syndrome (RDS): This breathing difficulty happens in infants who do not have fully developed lungs.
- Lack of oxygen before or during birth.
- Diaphragmatic hernia: This refers to a hole in the diaphragm, which is the muscle that keeps the chest separate from the abdomen. A hernia is when organs from one side push through the hole--in this case, organs from the abdomen intrude on the chest.
Symptoms and Causes
What causes persistent pulmonary hypertension in the neonate (PPHN)?
The cause of PPHN is not known.
In PPHN, failure of lung vessels to open enough can cause “back-pressure” and force the heart to keep using “fetal” (pre-birth) circulation pathways. These shortcuts (illustration above) ― the ductus arteriosus (DA) and the foramen ovale (FO) ― allow low-oxygen blood to mix in with blood pumped to the rest of the baby’s body.
What are symptoms of persistent pulmonary hypertension in the neonate (PPHN)?
Symptoms of PPHN include:
- Breathing problems such as rapid or slow breathing, grunting, and retracting.
- Blue color to the skin.
- Hands and feet that are cool to the touch.
- Low blood pressure throughout the body.
- Low blood oxygen levels.
Diagnosis and Tests
How is persistent pulmonary hypertension in the neonate (PPHN) diagnosed?
The following tests may be used to diagnose PPHN:
- Blood tests.
- Pulse oximetry (a noninvasive way to measure oxygen levels in the blood).
- Chest X-ray.
- Echocardiogram (a detailed ultrasound of the baby’s heart).
Management and Treatment
How is persistent pulmonary hypertension in the neonate (PPHN) treated?
The treatment of PPHN may include:
- Use of oxygen.
- Use of a special ventilator that breathes for the baby at a very fast rate.
- Blood pressure support, such as giving medicine intravenously (IV or through the vein).
- Use of nitric oxide, which helps to dilate or open up the pulmonary vasculature (blood vessels in the lungs).
- Use of a temporary heart-lung bypass, called extracorporeal membrane oxygenation (ECMO), as a rescue therapy.
Outlook / Prognosis
How long will it take to recover from persistent pulmonary hypertension in the neonate (PPHN)?
After treatment for pulmonary hypertension, your baby’s lungs will take weeks or even months to recover fully. It will be important to help protect your baby from catching colds or flu bugs. You can help with this by practicing good hand washing and keeping your baby away from sick people and large crowds. It will also be especially important for your baby to see his or her pediatric healthcare provider and other specialists regularly to be screened for normal developmental milestones.