Pulmonary Interstitial Emphysema

What is pulmonary interstitial emphysema?

Pulmonary interstitial emphysema (PIE) is when air gets trapped in the tissue outside the tubes and air sacs of the lungs. It affects newborn babies. PIE is fairly common in neonatal intensive care units.

When you breathe, air travels in through your mouth through a series of tubes to your lungs. At the ends of these tubes are tiny air sacs called alveoli. In these sacs is where gases get exchanged. Here, the lungs deliver oxygen to the blood. And they release carbon dioxide, a waste product. The oxygen then travels through the blood to all the organs of your body.

Normally, air is only found in these respiratory tubes or tiny sacs of the lungs. But in some cases, air can escape into the nearby tissue around the tiny sacs. This tissue is called the interstitium. This can happen if the wall of an air sac breaks open. If enough air leaks out, this can cause problems with breathing and blood flow. PIE is one type of pulmonary air leak syndrome.

PIE usually affects low-weight infants who need a ventilator. This is a device that assists with breathing. These infants often have a lung problem that is caused by preterm birth. PIE usually affects infants in the first few days of life. It may affect one or both lungs.

PIE is classified by how long it lasts. Acute PIE lasts for less than a week. If it lasts longer, it is called persistent PIE. PIE may also be called diffuse or localized. Diffuse means it occurs in multiple locations in the lungs. Localized means it occurs in a single spot.


What causes pulmonary interstitial emphysema?

Air can leak from an air sac when the sac is overstretched. This may happen when air becomes trapped inside the sac. Or it may happen when the air is not evenly distributed in the lungs.

Being on a ventilator may cause PIE. During artificial ventilation, a ventilator applies air pressure to the air sacs of your child’s lungs. This helps your child breathe by opening closed-off lung sacs. But in some cases, this extra pressure can create a leak in an air sac. Lung disease makes it more likely that these air leaks will happen. Lung disease may be caused by immature lungs or other medical conditions.

What are the risks for pulmonary interstitial emphysema?

Most cases of PIE happen in newborns that have other lung problems. It is common in infants who need to be on a ventilator. Careful adjustment of ventilator settings may help reduce your child’s risk of PIE. Conditions that can increase the risk of PIE include:

  • Preterm birth, which often leads to respiratory disease
  • Failure of the lungs to develop properly (pulmonary hypoplasia)
  • Breathing in the first intestinal discharge (meconium) at birth
  • Pneumonia, a lung infection
  • Very fast breathing right after birth (transient tachypnea of the newborn)

What are the signs of pulmonary interstitial emphysema?

Signs of PIE usually appear within 4 days of birth. Mild PIE may have no signs. More severe PIE may cause signs of breathing difficulty, such as:

  • Grunting or other signs of trouble breathing
  • Fast breathing
  • Pale appearance
  • Parts of the body tinted blue (cyanosis) due to low oxygen in the blood

How is pulmonary interstitial emphysema diagnosed?

You may be asked about you and your child’s medical history. This may include information before, during, and after birth. Your child will have a physical exam. His or her heart and lungs may be checked. Blood tests may be done to look for signs of low levels of oxygen and high levels of carbon dioxide.

Your child may also have an imaging test, such as a chest X-ray or a chest computed tomography (CT) scan. Leaked air will often appear on both of these imaging tests.

How is pulmonary interstitial emphysema treated?

PIE is a serious condition. It can cause death if not properly treated. For this reason, treatment is done inside a neonatal intensive care unit (NICU).

Treatment is done to make sure your child gets enough oxygen. It also aims to prevent more air leaks. Treatment may include:

  • Lying your baby on the side with air leak, which helps move more air into the lung that is working well
  • Lowering ventilator pressure if possible, to help prevent more air leaks
  • Using high-frequency oscillatory ventilation, which may lower pressure in the air sacs
  • Giving extra oxygen

Your child’s vital signs and levels of oxygen in the blood are checked during the treatment. Your child may also need x-rays to check on the status of the air leaks as they heal.

In most cases, PIE gets better with these treatments, and the leaked air goes away.

If your child has a severe localized case of PIE, the medical team may collapse the lung with the air leak for a short time. This is so the air sac can heal. This is done by placing a breathing tube into the lung without the air leak. Or, air flow may be blocked for a short time to the lung with the air leak. Your child might need a breathing tube and ventilator support during this time.

In rare cases, a child might need to have part of a lung removed to treat PIE that does not go away.

Your child may also need treatment for other lung problems that may be causing the PIE.

What are the complications of pulmonary interstitial emphysema?

PIE can sometimes cause pneumothorax. This is air in the space between the outer lungs and the chest wall. This can make breathing problems worse. Your child may need ventilator support or a chest tube for a large pneumothorax.

Can pulmonary interstitial emphysema be prevented?

Preventing preterm birth may help prevent PIE. You can decrease the chance of preterm birth by:

  • Not smoking during pregnancy
  • Not using alcohol during pregnancy
  • Getting prenatal care throughout your pregnancy
  • Seeking medical attention at the first signs of preterm labor

Key points

Pulmonary interstitial emphysema (PIE) is when air gets trapped in the tissue outside the tubes and air sacs of the lungs. It affects newborn babies. PIE is fairly common in neonatal intensive care units.

  • Lung disease caused by preterm birth increases a child’s risk of PIE.
  • PIE can cause trouble breathing and low oxygen levels in the blood.
  • In most cases of PIE, the air leaks go away on their own with supportive care.
  • In rare cases, your child might need a lung deflated for a short time to help treat PIE. Surgery may be needed in rare cases.

Next steps

Tips to help you get the most from a visit to your health care provider:

  • Before your visit, write down questions you want answered.
  • Bring someone with you to help you ask questions and remember what your provider tells you.
  • At the visit, write down the names of new medicines, treatments, or tests, and any new instructions your provider gives you.
  • If you have a follow-up appointment, write down the date, time, and purpose for that visit.
  • Know how you can contact your provider if you have questions.