Hemothorax
Hemothorax
Excerpt from this eMedicine link: http://emedicine.medscape.com/article/425518-diagnosis
Image of chest x-ray showing hemothorax: http://emedicine.medscape.com/article/425518-media
Studies
* Chest radiography
o The upright chest radiograph is the ideal primary diagnostic study in the evaluation of hemothorax.
o In the normal unscarred pleural space, a hemothorax is noted as a meniscus of fluid blunting the costophrenic angle or diaphragmatic surface and tracking up the pleural margins of the chest wall when viewed on the upright chest x-ray film. This is essentially the same chest radiographic appearance found with any pleural effusion.
o In cases in which pleural scarring or symphysis is present, the collection may not be free to occupy the most dependent position within the thorax, but will fill whatever free pleural space is available. This situation may not create the classic appearance of a fluid layer on a chest x-ray film.
o As much as 400-500 mL of blood is required to obliterate the costophrenic angle as seen on an upright chest radiograph.
o In the acute trauma setting, the portable supine chest radiograph may be the first and only view available from which to make definitive decisions regarding therapy. The presence and size of a hemothorax is much more difficult to evaluate on supine films. As much as 1000 mL of blood may be missed when viewing a portable supine chest x-ray film. Only a general haziness of the affected hemithorax may be noted.
o In blunt trauma cases, hemothorax is frequently associated with other chest injuries visible on the chest radiograph, such as rib fractures, pneumothorax, or a widening of the superior mediastinum.
o Additional studies such as ultrasonography or CT scan may sometimes be required for identification and quantification of a hemothorax noted on a plain chest radiograph.
* Ultrasonography
o Trauma ultrasonography is used at some trauma centers in the initial evaluation of patients for hemothorax.
o One drawback of ultrasonography for the identification of traumatic hemothorax is that associated injuries readily seen on chest radiographs in the trauma patient, such as bony injuries, widened mediastinum, and pneumothorax, are not readily identifiable on chest ultrasonograph images.
o Ultrasonography more likely plays a complementary role in specific cases in which the chest x-ray findings of hemothorax are equivocal.
* CT scan
o CT scan is a highly accurate diagnostic study for pleural fluid or blood.
o In the trauma setting, it does not hold a primary role in the diagnosis of hemothorax but is complementary to chest radiography. Because many victims of blunt trauma do undergo a chest and/or abdominal CT scan evaluation, hemothorax not considered based on initial chest radiographs might be identified and treated.
o Presently, CT scan is of greatest value later in the course of the chest trauma patient for localization and quantification of any retained collections of clot within the pleural space. (6)
Categorised as: Hemothorax, chest x-ray