Right lung collapse in a ventilated patient due to mucus plug

Author: V. Dimov, M.D.
Reviewer: S. Randhawa, M.D.

A 32-year-old African American female (AAF) was admitted to the hospital with aspiration pneumonia and respiratory failure. She was not weanable from the ventilator and a tracheostomy was placed. The patient was admitted to an acute long-term care facility (LTAC) where she was following a chronic weaning protocol. While there, she had had a cardiorespiratory arrest and developed anoxic encephalopathy. The family is insisting on a full code status.

She is in an ICU on vent. The arterial blood gas analysis (ABGs) and CXRs show acute respiratory distress syndrome (ARDS). The serial CXRs reveal a worsening right lung collapse.

ABGs in ARDS (click to enlarge the image).

CXR with a right lung atelectasis and a shift of the mediastinum. An endotracheal tube (ETT) size 6 is too small to pass a bronschoscope for diagnosis and therapeutic suctioning (click to enlarge the image).

A persistent atelectasis (click to enlarge the image).

CXR report: Since yesterday, limited portable supine exam shows a stable opaque right thorax mediastinal shift to the right, likely collapse of right lung with an endobronchial obstruction including underlying neoplasm considered as well as mucus plugging bronchogenic obstruction. Haziness of left mid and lower lung likely represents layering of left pleural effusion. Right cardiac border remains obscured.

What is the reason for the right lung opacification?

A mucus plug is the most likely cause for lung collapse in this patient.

What would you do?

Bronchoscopy with mucus plug susctioning.

First, you have to check the size of the tracheostomy tube because an adult bronchoscope does not pass through a tube size smaller than 8.

The patient's ET tube size is 6. An ENT consult was called and the ET-tube was replaced with another one, size 8.

In the meantime, Mucomyst (acetylcysteine) aerosol q 4 hr was started.

What happened?

Two hours after the ET-tube was replaced and the tube was suctioned, the CXR showed a complete resolution of the right lung atelectasis. The oxygenation improved and the FiO2 was decreased. Mucomyst was stopped because it may act as an airway irritant on its own. A bronchoscopy was not needed.

The trachea was suctioned and the ETT was changed with a larger one, size 8. The removed ETT was filled with thick yellow-grey mucus. The follow-up CXR showed reexpansion of the right lung. See the close-up of the ETT, size 8 is the minimal size allowing the passage of a bronchoscope (click to enlarge the images).

CXR report: There is improved aeration of the right lung. There are infiltrates or atelectases in the both lungs with pleural effusions. There is again cardiomegaly with pulmonary venous hypertension and CHF. The life support device placement is unchanged.

ABGs showed a decrease in the required FiO2 after the atelectasis resolved (click to enlarge the image).

Final diagnosis

A right lung collapse in a ventilated patient due to a mucus plug.

What did we learn from this case?

There are several common causes for sudden deterioration of oxygenation of a ventilated patient:

-Pulmonary edema

An atelectasis is often due to a mucus plug and can be resolved by suctioning of the ETT.

In all cases of sudden deterioration, the patient needs a CXR immediately.

Related reading

Recurrent Aspiration Pneumonia. NEJM Images in Clinical Medicine, 11/2008.

Published: 03/02/2004
Updated: 11/10/2008


  1. hi i had my lung collapse due to an car accident injury and now i was told by a doctor that i have fibrosis, could the collapse of my right lung be the cause of this fibrosis.

  2. sorry its pulmonary fibrosis.

  3. Wouldn't it have been better to ask the doc who gave you the diagnosis?