Persistent pulmonary hypertension of the newborn (PPHN)

Overview

Persistent pulmonary hypertension of the newborn, or PPHN, occurs when a newborn's circulation system doesn't adapt to breathing outside the womb.

While in the womb, the fetus receives oxygen through the umbilical cord, so the lungs need little blood supply. There is high blood pressure in the lungs, so blood in the pulmonary artery is sent away from the lungs to the other organs through a fetal blood vessel, called the ductus arteriosus.

Normally, when a baby's born and begins breathing, the blood pressure in the lungs falls and blood flow to the lungs increases. Oxygen and carbon dioxide are exchanged in the lungs, then the blood is returned to the heart and pumped back out to the body. The ductus arteriosus constricts and permanently closes in the first day of life.

In babies with PPHN, the pressure in the lungs stays high and the ductus arterious remains open, allowing blood to be directed away from the lungs. PPHN is a rare but life-threatening condition that appears most often in full-term or post-term babies who have had a difficult birth or conditions such as infection or birth asphyxia.

Signs & symptoms

The signs and symptoms of persistent pulmonary hypertension of the newborn may include:

• Rapid breathing, also called tachypnea
• Rapid heart rate
• Respiratory distress, including signs such as flaring nostrils and grunting
• Cyanosis, a condition in which the baby's skin has a bluish tint even while he or she is receiving extra oxygen
• Heart murmur, where a baby has an extra or abnormal heart sound
• Low oxygen levels (a baby with PPHN may continue to have low oxygen levels in the blood even while receiving 100 percent oxygen)

Diagnosis

Various imaging and laboratory tests can help determine if a baby has persistent pulmonary hypertension of the newborn. These may include:

• Chest X-rays to determine if the baby has lung disease or an enlarged heart
• Echocardiogram — an ultrasound of the heart — to determine if the baby has heart or lung disease and evaluate blood flow in those organs
• Ultrasound of the head to look for bleeding in the brain
• Arterial blood gas (ABG) to determine how well oxygen is being delivered to the body
• Complete blood count (CBC) to measure the number of oxygen-carrying red blood cells, white blood cells and platelets.
• Serum electrolyte tests to evaluate the balance of minerals in the blood
• Lumbar puncture, also called a spinal tap, and blood tests to help determine whether the baby has an infection
• Pulse oximetry, which measures oxygen levels in the blood, to help monitor whether the baby's tissues are receiving enough oxygen

Treatment

In treatment for PPHN, the main goal is to increase oxygen flow to the baby's organs to prevent serious health problems. Treatment may include a wide range of mechanical ventilation and respiratory therapy options such as:

• Oxygen — 100 percent supplemental oxygen may be given to your baby through a mask or plastic hood.
• Assisted ventilation — During this procedure, a tube is inserted into your baby's windpipe, a ventilator takes over your baby's breathing and oxygen is given.
• Nitric oxide — Research has shown that this gas is effective in treating PPHN because it relaxes contracted lung blood vessels and improves blood flow to the lungs. It is given through the ventilator.
• High frequency oscillatory ventilation — This type of ventilation may improve the oxygen level in the blood if other types of ventilation aren't effective.

Extracorporeal Membrane Oxygenation (ECMO)

In addition, an extracorporeal membrane oxygenation (ECMO) machine may be used for babies who are experiencing serious heart or lung failure. The ECMO delivers oxygen to the brain and body as temporary support while the PPHN resolves. ECMO is similar to a heart-lung bypass machine, which takes over your baby's heart and lung functions with an external pump and oxygenator. Blood is drained from the baby to an artificial lung, where oxygen is added and carbon dioxide is removed, then the blood is pumped back into your child.

At UCSF Benioff Children's Hospital, we treat over 20 patients each year with ECMO and our success outcomes are among the highest in the country. Our team includes a neonatologist, surgeon, respiratory therapists and nurses with special training in the management of ECMO.