Learning Objectives:

  1. Describe the indications and limitations of POC thoracic US

  2. Perform POCUS protocols for the detection of: 

    • Pneumothorax

    • Pleural Effusion

    • Acute Interstitial Syndrome (CHF, ARDS, focal or multifocal pneumonia, pulmonary contusion)

    • Pneumonia

  3. Identify relevant US anatomy of thoracic structures 

  4. Recognize the relevant findings and pitfalls when evaluating for thoracic pathology

  5. Recognize the sonographic findings of tracheal and esophageal anatomy, especially in regard to EM procedures

  6. Integrate thoracic CUS findings into individual patient and departmental management.


Indications:

  • Acute pneumothorax

  • Abnormal pleural fluid collections

  • Presence of interstitial lung fluid (CHF, ARDS)

Extended Indications:

  • Identification of pneumonia, rib fractures, pulmonary fibrosis

  • Use POC thoracic ultrasound to guide thoracentesis or tube thoracostomy

Required Views:

  • Depth ≥ 12cm

  • At least 2 lung views on each side (4 total)

  • RUQ & LUQ pleural views if applicable (to assess for pleural effusion)

ANATOMY:

How to Scan:

How to Perform a Pulmonary Ultrasound Exam

POCUS101 Lung Ultrasound Made Easy

Tips/Tricks/Pitfalls:

  • Presence of lung slide reliably rules out pneumothorax in the area being scanned (highly sensitive)

  • The absence of lung slide does not always diagnose pneumothorax. Prior pleurodesis, scarring, mainstem intubation of contralateral lung, blebs, severe reactive airway disease, and bronchial obstruction can also cause this finding.

  • A “transition point” or “lung point” where absent lung slide meets dynamic pleural sliding is highly specific for the diagnosis of pneumothorax.

  • Remember to use enough depth (≥12 cm) when assessing the lung parenchyma. 

  • Lung ultrasound can help to differentiate a simple pleural effusion from a complex and/or loculated pleural effusion and help guide a safer thoracentesis or pigtail tube thoracostomy.  

  • Presence of B-lines may indicate EITHER pulmonary edema or an inflammatory process while the presence of subpleural consolidation or “shred sign” indicate a focal inflammatory process.

Pathology:

  • Pneumothorax 

  • Pleural Effusion

  • Acute Interstitial Syndrome (focal or diffuse)

  • Pneumonia (focal or multifocal B-lines, subpleural consolidation, “shred sign”)

Key Literature:

  1. Lichtenstein DA, Mezière GA. Relevance of lung ultrasound in the diagnosis of acute respiratory failure: the BLUE protocol. Chest. 2008 Jul;134(1):117-25. doi: 10.1378/chest.07-2800. Epub 2008 Apr 10. Erratum in: Chest. 2013 Aug;144(2):721. PMID: 18403664; PMCID: PMC3734893. Link: https://pmc.ncbi.nlm.nih.gov/articles/PMC3734893/

  2. Lichtenstein, D.A. Lung ultrasound in the critically ill. Ann. Intensive Care 4, 1 (2014). https://doi.org/10.1186/2110-5820-4-1

    Link: https://annalsofintensivecare.springeropen.com/articles/10.1186/2110-5820-4-1

Additional Resources:

Taming the SRU (Lung) - how-to-scan video, case examples

The POCUS Atlas (Pulmonary) - excellent clips of both normal and abnormal lung pathology

5 Minute Sono - Lung - 5 minute lectures on various different pathologies you should be scanning for

Author: Susan Mari, MD (PGY-3)

Peer editing by: David Murray, MD FPD-AEMUS