Pulmonary interstitial emphysema (PIE) refers to a collection of air and gases outside the alveoli, the tiny sacs in the lungs that usually take in air. This trapped air causes pressure in the lungs and damages lung tissue.
PIE is a
Premature birth can often result in a baby having underdeveloped lungs. They may develop PIE during their time in the neonatal intensive care unit (NICU).
The outlook for babies with PIE is typically not good because they are often already very sick. Babies who survive may have chronic lung issues, and PIE could result in pneumothorax, which is a collapsed lung.
In this article, we discuss PIE and its symptoms and causes. We also look at the potential treatment options and the outlook for people with the condition.
PIE happens when the air becomes trapped outside the lungs’ air sacs.
Typically, the alveoli absorb air and exchange carbon dioxide and oxygen. Sometimes, the air escapes from the alveoli and enters the interstitial tissue nearby, damaging the lungs and causing PIE.
PIE frequently occurs in babies admitted to the NICU, especially those born very early or with low birth weight.
- 42% among infants weighing 500–799 grams (g)
- 29% among infants weighing 800–899 g
- 20% among infants weighing 900–999 g
Doctors classify PIE in the following ways according to how much tissue it affects and how long it lasts:
- Acute: Acute PIE is a short-term phenomenon that lasts less than a week.
- Chronic: Chronic or persistent PIE lasts longer than a week.
- Localized: This means that PIE affects a small portion of the lungs.
- Diffuse: This indicates that the condition affects a larger area of the lungs.
PIE can affect adults, but this is uncommon, and few studies have addressed it.
A 2014 study reviewed the records of 53 lung transplants in adults and found that PIE was common, affecting 36% of these individuals.
PIE was more common among people with interstitial pneumonia, a type of lung inflammation that surrounds the air sacs of the lungs. However, the researchers found no correlation between PIE and the duration of pneumonia. People with a history of lung biopsies or being on a ventilator were also more likely to develop PIE.
PIE generally causes people, both babies and adults, to be very sick, with severe underlying lung or respiratory disease. PIE may not cause additional distinct symptoms. Instead, doctors base the diagnosis on lab testing, including a lung scan.
The possible symptoms of PIE include:
- grunting or wheezing
- breathing difficulties
- paleness, which might not be apparent in people with dark skin
- peripheral cyanosis, in which the extremities turn blue
- trouble eating
These symptoms may exist before PIE, and they have other possible causes. Due to this, doctors cannot make a diagnosis of PIE based on symptoms alone.
In adults, PIE is usually a complication of underlying lung disease or interventions to treat lung disease. Adults with lung disease risk factors, such as asthma or a history of smoking, have a higher risk.
In babies, the
Prematurity and low birth weight often mean that the lungs are not well-developed, meaning that the baby needs various treatments to ensure that they can breathe. However, these treatments could change the air pressure in the lungs and alveoli, causing the alveoli to break open and leading to PIE.
Doctors may suspect PIE based on a baby’s age, birth weight, and other risk factors.
Preventive strategies may
Positioning the baby in a side-lying position called lateral decubitus may help treat PIE. This strategy works best when the condition affects one lung to a greater extent than the other.
Other treatment options depend on the severity of the disease and the baby’s health. They include:
- Ventilation: High frequency ventilation may lower the risk of PIE. It may also prevent lung damage in babies who already have PIE. This type of ventilation produces less pressure, decreasing the damage that air leaks cause.
- Medication: A doctor may recommend drugs such as steroids to improve lung function.
- Lobectomy: This procedure involves removing portions of the affected lung. As it is very invasive, doctors only use it as a last resort treatment when other strategies do not work.
Babies who develop PIE tend to be very sick. Those with PIE and severe respiratory distress have mortality rates as high as
Babies who survive may have long-term complications. About half develop chronic emphysema, and half need to undergo the removal of portions of their lungs.
Researchers have not thoroughly studied the outlook for adults with PIE.
PIE is a serious medical condition that usually only occurs in very unwell babies. The presence of PIE usually signals a downturn in the baby’s overall health.
Once doctors have diagnosed PIE in a baby, the parents or caregivers should ask questions about the long-term outlook, palliative care measures, and potential treatment options. It may sometimes be helpful to seek a second opinion.
Navigating a severe diagnosis can be worrying, but the NICU is the safest place for the baby to get comprehensive care. Parents and caregivers may wish to consider exploring NICU options ahead of time if they have risk factors for premature birth or low birth weight.