Last revised by Rania Adel Anan on 1 Dec 2022

A hemothorax (plural: hemothoraces), or rarely hematothorax, literally means blood within the chest, is a term usually used to describe a pleural effusion due to accumulation of blood. If a hemothorax occurs concurrently with a pneumothorax it is then termed a hemopneumothorax

A tension hemothorax refers to hemothorax that results from massive intrathoracic bleeding, causing ipsilateral lung compression and mediastinal displacement 9.

Hemothoraces usually present with dyspnea or thoracic pain. Patients typically have a history of trauma or malignancy.

Complications that can occur after a retained hemothorax include 7:

A hemothorax is sometimes defined as pleural fluid with a hematocrit ≥50% of the peripheral blood hematocrit.

It usually occurs from penetrating or blunt trauma 3 to the chest (traumatic hemothorax). 

A hemothorax can also occur without trauma, in which case it is termed a spontaneous hemothorax. This can occur in the setting of 8:

Chest radiographic appearance of a large hemothorax may be similar to that of a pleural effusion. It can be almost impossible to differentiate a hemothorax from other causes of pleural effusions.

Ultrasound has a very high sensitivity (92%), specificity (100%), positive predictive values (100%), and negative predictive values (98%) for the detection of a hemothorax in the context of preceding trauma 2. Sonographic features characteristic, albeit nonspecific, of hemothoraces include 12:

  • homogenously echogenic effusion
    • typical of hemothoraces in the acute stage
  • plankton sign 
  • hematocrit sign 11
    • implies collection has been present for a longer period of time  
    • the cellular component may layer in the posterior costophrenic recess, creating an interface with the superficial anechoic layer

CT is useful in determining the nature of the pleural fluid in the setting of trauma by assessing the attenuation value. Blood in the pleural space typically has an attenuation of 35-70 HU 6. Pleural fluid attenuation measurement should be routine in the interpretation of chest trauma CT to distinguish simple fluid from acute blood.

In the setting of trauma, there may be other ancillary features such as pulmonary contusions and lacerations.

The exact management strategy will depend on the underlying etiology. In general, drainage is performed for symptomatic therapy.

For a clotted hemothorax options include:

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