Haemothorax

A pleural effusion on EFAST is assumed to be a haemothorax. The easiest way to diagnose a haemothorax in the supine patient is to visualise the spine extending above the diaphragm in the RUQ and LUQ. The spine sign has a high sensitivity and specificity for the diagnosis of haemothorax in trauma (1,2,3). Often showing an effusion undetectable on CXR (4).

For more detailed information on how to find the spine sign please see the pleural effusion section in Lung

Usually, the haemothorax is anechoic (5). However, with time, due to organisation and clot formation, you will see echogenic material within the effusion on US (6). With delayed presentation, the fluid becomes hypoechoic and homogenous. 

REFERENCES

1.Brooks A, Davies B, Smethhurst M, et al. Emergency ultrasound in the acute assessment of haemothorax. Emerg Med J 2004;21:44–6.

2. Ma OJ, Mateer JR. Trauma ultrasound examination versus chest radiography in the detection of hemothorax. Ann Emerg Med 1997;29:312–5.

3. Sisley AC, Rozyyeki GS. Rapid detection of traumatic effusion on using surgeon- performed ultrasonography. J Trauma 1998;44:291.

4. Rahimi-Movaghar V, Yousefifard M, Ghelichkhani P, Baikpour M, Tafakhori A, Asady H, Faridaalaee G, Hosseini M, Safari S. Application of Ultrasonography and Radiography in Detection of Hemothorax; a Systematic Review and Meta-Analysis. Emerg (Tehran). 2016 Summer;4(3):116-26.

5. Dietrich CF, Mathis G, Cui XW, Ignee A, Hocke M, Hirche TO. Ultrasound of the pleurae and lungs. Ultrasound Med Biol. 2015 Feb;41(2):351-65.

6. Patel KM, Ullah K, Patail H, Ahmad S. Ultrasound for Pleural Disease. Beyond a Pocket of Pleural Fluid. Ann Am Thorac Soc. 2021 May;18(5):749-756.