Persistent pulmonary hypertension of the newborn or PPHN is the failure of the normal circulatory transition that occurs after birth. A syndrome that is characterized by marked pulmonary hypertension and this causes hypoxemia and right-to-left extrapulmonary blood shunting.
What is shunting of blood?
There is the patent foramen ovale and patent ductus arteriosus that are present early in life, elevated pulmonary vascular resistnace in the newborn can produce shunting of blood which will lead to a severe and potential unresponsive hypoxemia. If there is inadequate pulmonary perfusion, neonates are at risk for developing refractory hypoxemia, respiratory distress and acidosis.
There are different types of persistent pulmonary hypertension of the newborn:
- PPHN characterized by abnormally constricted pulmonary vasculature due to lung parenchymal diseases.
- PPHN characterized by hypoplastic vasculature.
- PPHN in which the lung has normal parenchyma and remodeled pulmonary vasculature.
Causes of persistent pulmonary hypertension of the newborn
The cause of persistent pilmonary hypertensiion is usually unknown. Some researchers believe that stress while the baby is in the uterus that is associated with pregnancy complications may increase the risk of developing PPHN.
Persistent pulmonary hypertension of the newborn may also occur with certain diseases or congenital conditions of the newborn that affects the lungs.
Signs and symptoms of persistent pulmonary hypertension of the newborn:
- rapid breathing or tachypnea
- rapid heart rate
- respiratory distress
- cyanosis
- heart murmur
How is persistent pulmonary hypertension of the newborn diagnosed?
Several tests will be performed:
- Chest X-rays – it can show if the baby has lung disease and whether the heart is enlarged
- Echocardiogram – this can show whether the haby has heart or ling disease and can determine the direction of the blood flow in those organs.
- An ultrasound of the head
- Arterial blood gas – this can determine the amount of oxygen, carbon dioxide and acid buildup are in the arterial blood.
- CBC – this measures the number of oxygen-carrying red blood cells, white blood cells, and platelets.
- Serum electrolyte tests – this can evaluate the balance of minerals in the blood.
- Lumbar puncture
- Pulse oximetry
How is persistent persistent pulmonary hypertension of the newborn treated?
Usually, babies with PPHN are cared for in a neonatal intensive care unit. The doctor will maximize the amount of oxygen delivered to the lungs of the baby so 100% oxygen will be given through a tube inserted directly into the baby’s trachea.
Another way is through the use of high-frequency oscillatory ventilation if the baby has PPHN that is caused by a lung problem. This is a ventilation technique that can improve the oxygen deleivery to the lungs and it can also reduce acid buildup in the blood and it often helps open up the blood vessels leading to the lungs and thus allowing more blood to flow to the lungs.
Nitric oxide is also said to be effective to babies with persistentg pulmonary hypertension.
Lastly, extracorporeal membrane oxygenation is an intensive procedure and this will require major surgery.