Pulmonary interstitial emphysema (PIE) is a rare lung condition that involves air leaking out of the alveoli (air sacs) in the lungs.

PIE is most common in newborns, particularly low weight or premature infants. It’s a lot less common in adults, although it can develop in certain cases.

This article will take a closer look at PIE, including its symptoms, treatments, and outlook.

When you breathe in, air moves from your mouth and nose through your windpipe and to each lung through your bronchial tubes.

From there, the air goes into your smaller airways, including the bronchi and bronchioles, before reaching your alveoli. These tiny sacs (you have about 480 million of them in your lungs) help move oxygen into your blood. They also release carbon dioxide (a waste product) as you breathe out.

With PIE, some air escapes the alveoli, creates pressure, and goes into nearby tissues. When this happens, it can affect your breathing and the flow of oxygen-rich blood through your body.

PIE can be split into different classifications:

  • Acute PIE lasts less than a week.
  • Persistent PIE lasts longer than a week.
  • Localized PIE occurs in just one spot in the lungs.
  • Diffuse PIE occurs in many spots in the lungs.

Newborns and premature infants have the highest risk of developing PIE. This is because their lungs may not be fully developed at birth.

In particular, infants who weigh under 1,000 grams at birth have a 20 to 42 percent risk of developing this condition.

Adults who get PIE tend to have chronic lung conditions or have been on ventilators to treat those conditions.

Babies who are born prematurely may develop PIE because their lungs are not fully developed.

Specifically, the lungs are supposed to make a substance called surfactant that keeps the alveoli pliable and less likely to break open. Without this substance, an infant has a higher risk of developing PIE.

Other factors that may increase an infant’s risk of developing PIE include:

Adults have a higher risk of developing PIE due to:

Symptoms may first crop up in the days or weeks following birth. Mild cases of PIE may not have noticeable symptoms.

Signs of more serious PIE include:

  • issues with breathing (rapid breathing, labored breathing)
  • grunting
  • pallor
  • cyanosis (for example, blue-looking lips from low oxygen levels)

In addition, adults may experience:

  • wheezing
  • coughing
  • a feeling of tightness in the chest

If you’re pregnant, there are some things you can do to prevent PIE in your newborn.

Since PIE is often caused by premature birth, getting regular prenatal care may help prevent PIE. Also, talk with a doctor if you smoke, drink, use recreational drugs, or have any other risk factors for preterm birth.

Adults with PIE tend to develop it as the result of being on ventilators for lung conditions, or from undergoing other lung procedures, such as a lung biopsy.

Researchers explain that awareness by medical staff about the condition and using alternative or protective ventilation methods may prevent it from developing.

Doctors diagnose PIE using imaging, like a chest X-ray or a chest CT scan. The images collected may show leaked air in the lungs.

Other diagnostic tests might include blood tests to see how much oxygen is circulating in the blood and histopathology, which allows doctors to examine tissues under a microscope.

Treatments for PIE include:

  • Lateral decubitus positioning. The most conservative treatment involves placing a baby in a specific position (lying on the side that has the air leak) to facilitate better air movement in the lungs.
  • Surfactant. Natural or synthetic surfactant may be administered through the trachea to reach the alveoli.
  • Ventilation. Ventilators can be a cause of PIE, but high frequency positive pressure ventilation may help it. The way this ventilation differs is that it makes less pressure in the lungs than standard ventilation.
  • Lobectomy. A lobectomy involves surgically removing the affected lobe of the lungs. This is considered a last resort treatment because it’s invasive. However, it may be needed in the most severe cases.
  • Other treatments. Your child’s doctor may suggest medications, like steroids, oxygen therapy, or nitric oxide treatments. More research is needed on these treatments to evaluate their effectiveness.

According to research, the outlook for infants with PIE can be challenging, particularly if PIE is diagnosed within 48 hours of birth. Some studies indicate the death rate of this condition is somewhere between 53 and 67 percent for infants.

Size matters, too. Infants who weigh under 1,600 grams and also have severe respiratory distress may have up to an 80 percent chance of death.

Babies also face an additional risk of developing long lasting lung issues, like chronic emphysema.

But you can help prevent PIE from developing by getting regular prenatal care and reducing the risks of premature birth, like stopping smoking and drinking alcohol.

Getting prompt treatment may help improve the outlook, too.

Other potential complications of PIE include:

PIE is a rare but serious lung condition that affects infants and sometimes adults. It’s most common in low weight newborns and premature babies.

Scheduling proper prenatal care, not smoking or drinking during pregnancy, and getting prompt medical attention for preterm labor may help reduce the risk of this condition in newborn infants.

Although death rates are high for the smallest babies, PIE can resolve within a few weeks with appropriate care and treatment.