Category: Ultrasound
Keywords: POCUS, Trauma, Cardiac Tamponade, Pericardial Effusion, FAST exam (PubMed Search)
Posted: 8/5/2024 by Alexis Salerno, MD
Click here to contact Alexis Salerno, MD
In a critically ill trauma patient, the FAST exam is used to evaluate for potential internal injuries. Specifically, the subxiphoid view of the FAST exam helps assess for signs of pericardial tamponade. However, distinguishing between a pericardial effusion and an epicardial fat pad can be challenging.
One study indicated that the sensitivity of EPs in differentiating between effusion and fat pad was 73%, with a specificity of 44% when reviewing difficult patient video clips.
Here are some tips to help you distinguish between effusion and fat pad:
Change your view: Use the parasternal long axis view, which is more sensitive for effusion. Fat pads are usually anteriorly, and effusions tend to accumulate posteriorly in a supine patient.
Screen for other signs of tamponade: Adjust your subxiphoid view to visualize the IVC entering the right atrium, allowing better visualization of the right side of the heart.
Movement: Fat tends to move synchronously with the heart, whereas hemopericardium moves independently.
Echogenicity: Fat typically appears brighter on ultrasound, while blood tends to be less echogenic.
For further learning, refer to the supplemental Material from the referenced articles.
Bronshteyn YS, Hashmi N, Privratsky JR, Barbeito A. Blood or Fat? Differentiating Hemopericardium versus Epicardial Fat Using Focused Cardiac Ultrasound. Diagnostics (Basel). 2024 Apr 15;14(8):818. doi: 10.3390/diagnostics14080818. PMID: 38667464
Blaivas M, DeBehnke D, Phelan MB. Potential errors in the diagnosis of pericardial effusion on trauma ultrasound for penetrating injuries. Acad Emerg Med. 2000 Nov;7(11):1261-6. doi: 10.1111/j.1553-2712.2000.tb00472.x
