Lobar atelectasis refers to the collapse of alveoli in an entire lung segment. It is a common complication after surgery and can affect a patient’s ability to perform gas exchange.

In this article, we will discuss the causes, symptoms, diagnosis, types, and treatment methods for lobar atelectasis.

What is Atelectasis?

As you take a breath in, air moves through your mouth and trachea down through the airways of the lungs until it reaches the tiny air sacs that are known as alveoli.

This is where the gas exchange of oxygen and carbon dioxide takes place.

Therefore, if air fails to reach this region, it can result in many different problems within the body. When this occurs, the alveoli that are not filled with air cannot expand, and this is known as atelectasis.

When this occurs in a specific lung segment, it is referred to as lobar atelectasis.

Causes of Lobar Atelectasis

Lobar atelectasis can occur in newborn infants due to a lack of surfactant.

It is also commonly seen in surgical patients, which can occur during or after the procedure. That is because a surgical procedure often results in shallow breathing, which means that not enough air will reach the alveolar region.

Some other causes of lobar atelectasis include:

  • Airway obstruction
  • Mucus plug
  • Lung tumor
  • Pleural effusion
  • Pneumothorax
  • Tuberculosis
  • Respiratory muscle weakness

Those who smoke cigarettes and the elderly population are also at a higher risk for atelectasis.

In addition, significant atelectasis can be seen on a chest radiograph where the findings would show lung opacification in that area.

Signs and Symptoms

Lobar atelectasis can result in several different signs and symptoms, including the following:

  • Shortness of breath
  • Diminished breath sounds
  • Shallowing breathing
  • Persistent cough
  • Chest pain

The symptoms of lobar atelectasis can vary depending on the underlying cause and the severity of the lung collapse.


Lobar atelectasis can be treated by correcting the underlying cause. However, post-surgical atelectasis can be treated or prevented with different types of lung expansion therapy.

The most common type involves the use of an incentive spirometer, which helps the patient take deep breaths to open up and expand the collapsed alveoli in the lobe or segment that is affected.

Patients are typically instructed to use the spirometer 10 times per hour to treat or prevent atelectasis.


Lobar atelectasis is typically diagnosed with a chest radiograph, which shows an area of collapse within a specific lobe.

It can also be diagnosed with a physical examination, where decreased breath sounds in the affected area will be heard during auscultation.

A bedside ultrasound may also be used when atelectasis is suspected. In some cases, a CT scan may be ordered to confirm the diagnosis.

Types of Lobar Atelectasis

There are several types of lobar atelectasis, including the following:

  • Right upper lobar atelectasis
  • Left upper lobar atelectasis
  • Right middle lobar atelectasis
  • Lower lobar atelectasis
  • Combined lobar atelectasis
  • Combined atelectasis of the right middle and lower lobes
  • Combined atelectasis of the right upper and middle lobes
  • Combined atelectasis of the right upper and lower lobes
  • Peripheral lobar atelectasis
  • Migrating lobar atelectasis
  • Rounded atelectasis

Each type will reveal different findings on a chest radiograph, which can be interpreted by a qualified practitioner.

How Serious is Lobar Atelectasis?

The severity of lobar atelectasis will vary depending on the extent of the collapse and the underlying cause.

In some cases, it may resolve on its own with no treatment, while other times it may require more aggressive treatment, such as different types of lung expansion therapy.

In severe cases, it can lead to respiratory failure.


What is Bibasilar Atelectasis?

Bibasilar atelectasis is a type of atelectasis that occurs in both lungs, usually in the lower lobes or segments. The severity of this type depends on the extent of the lung collapse.

What is Subsegmental Atelectasis?

Subsegmental atelectasis is a type of atelectasis that affects a small area of the lung, usually less than one bronchopulmonary segment. This is considered to be the mildest type of atelectasis.

What is Linear Atelectasis?

Linear atelectasis is a subtype of subsegmental atelectasis that occurs when there is a collapse in less than one bronchopulmonary segment of the lung. It usually occurs in the lung bases and is secondary to hypoventilation.

What is Postoperative Atelectasis?

Postoperative atelectasis is a type of atelectasis that occurs after surgery. Postoperative patients tend to take shallow breaths after the procedure due to pain.

This results in a decrease in functional residual capacity (FRC), which causes atelectasis in one or more lung segments.

Final Thoughts

Lobar atelectasis is a condition that occurs when air fails to reach the alveoli, resulting in a collapse of the affected lobe or segment.

It can be caused by a variety of different factors, including surgical procedures, airway obstructions, and respiratory muscle weakness.

Lobar atelectasis is typically diagnosed with a chest radiograph, which will show an area of collapse. In some cases, a CT scan may be ordered to confirm the diagnosis.

Treatment of lobar atelectasis typically involves correcting the underlying cause. However, post-surgical atelectasis can be treated or prevented with different types of lung expansion therapy, such as incentive spirometry.

In severe cases, lobar atelectasis can lead to respiratory failure. Thanks for reading, and, as always, breathe easy, my friend.

Written by:

John Landry, BS, RRT

John Landry is a registered respiratory therapist from Memphis, TN, and has a bachelor's degree in kinesiology. He enjoys using evidence-based research to help others breathe easier and live a healthier life.


  • Egan’s Fundamentals of Respiratory Care. 12th ed., Mosby, 2020.
  • Clinical Manifestations and Assessment of Respiratory Disease. 8th ed., Mosby, 2019.
  • Ashizawa, K., et al. “Lobar Atelectasis: Diagnostic Pitfalls on Chest Radiography.” National Library of Medicine, Br J Radiol, Jan. 2001, pubmed.ncbi.nlm.nih.gov/11227785.
  • Grott, Kelly, et al. “Atelectasis.” National Library of Medicine, Jan. 2022, www.ncbi.nlm.nih.gov/books/NBK545316.Coming soon!

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Medical Disclaimer: The information provided by Respiratory Therapy Zone is for educational and informational purposes only. It should not be used as a substitute for professional medical advice, diagnosis, or treatment. Please consult with a physician with any questions that you may have regarding a medical condition.