Understanding Collapsed Lungs in Premature Babies

Atelectasis and Pneumothorax in the NICU

adult holding premature baby's hand
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What Is a Collapsed Lung?

A collapsed lung is a medical problem that happens when parts of the lungs collapse, making it hard to breathe. The lungs are made up of airways that spread out like tree branches from large airways (bronchi) to smaller airways (bronchioles). At the ends of the airways are the alveoli--tiny bubbles that do all of the real work in the lungs, exchanging oxygen and carbon dioxide.

When the lungs collapse, the collapse of the alveoli makes gas exchange impossible in the affected areas. There are many different things that can cause the alveoli to collapse, but the two most common types of collapsed lungs in the NICU are atelectasis and pneumothorax.

Pneumothorax in the NICU

A pneumothorax is a collection of air inside the chest cavity. Pneumothorax causes collapsed lungs in two ways. First, the air inside the chest can press on the lungs, collapsing them under pressure. Second, the alveoli can burst, leaking air inside the chest and collapsing the alveoli themselves.

A pneumothorax can range from a mild problem or a life threatening medical emergency, depending on how much air is in the chest and how much trouble breathing the baby is having. If your baby has a "pneumo," physicians may treat it in one of the following ways:

  • Careful monitoring: Sometimes no treatment is necessary, other than carefully watching the baby for signs of trouble breathing. The body will reabsorb the air over time.
  • Extra oxygen: In full-term babies, extra oxygen is sometimes used to help the body to reabsorb the air faster.
  • Needle aspiration: A needle can be inserted into the chest, and the air withdrawn into a syringe.
  • Chest tube: In severe pneumos, a chest tube will be inserted and left in to continuously remove air from the chest cavity. 

    Read More: Pneumothorax in Premature Babies

    Atelectasis in the NICU

    Atelectasis is another common type of collapsed lung in the NICU. In atelectasis, the alveoli collapse without bursting. No air leaks out, but gas exchange can't occur. The lungs can't get enough oxygen to the rest of the body, and the baby develops trouble breathing and staying oxygenated.

    Treatment for atelectasis is based on its cause. Common causes of atelectasis include:

    • Prematurity: Premature babies don't have enough surfactant, a chemical in the body that helps keep alveoli open. Physicians can give artificial surfactant to the baby to help keep the alveoli open.
    • Meconium aspiration: If babies inhale meconium during delivery, it can clog airways so that air can't enter the alveoli. Respiratory support such as CPAP can increase airflow to the lungs, helping the alveoli stay open.
    • Pneumonia: Lung infections such as pneumonia can cause mucous to fill the lungs, blocking airflow to the alveoli. Physicians may treat the pneumonia with medication, and use respiratory support to keep the lungs inflated.

    Read More: Atelectasis in Premature Babies

    Other Types of Collapsed Lungs in the NICU

    Although pneumothorax and atelectasis are the most common causes of collapsed lungs in the NICU, other rare conditions can cause the lungs to collapse or to grow poorly.

    Congenital diaphragmatic hernia (CDH) is a serious medical condition where the intestines enter the chest cavity through a hole in the diaphragm. The intestines press on the lungs, collapsing them and preventing proper growth. Low amniotic fluid volume (oligohydramnios) in the mother can also cause the lungs to grow poorly and to be smaller than average, a condition called pulmonary hypoplasia that is similar to collapsed lungs.


    Jones, P. (2013) NYU Langone Medical Center. "Atelectasis in Infants."

    University of Rochester Medical Center Health Encyclopedia. "Pneumothorax."

    Litmanovitz, I. & Carlo, W. (Nov. 2008). "Expectant Management of Pneumothorax in Ventilated Neonates." Pediatrics, 122(5); e975-e979.

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