In hemothorax, blood from damaged intercostal, pleural, mediastinal and, infrequently, lung parenchymal vessels enters the pleural cavity. Depending on the amount of bleeding and the underlying cause, hemothorax may be associated with varying degrees of lung collapse and mediastinal shift. Pneumo-thorax—air in the pleural cavity — commonly accompanies hemothorax.
Hemothorax usually results from blunt or penetrating chest trauma; in fact, about 25% of patients with such trauma have hemothorax. Less commonly, it results from thoracic surgery, pulmonary infarction, neoplasm, dissecting thoracic aneurysm, or anticoagulant therapy.
Signs and symptoms
The patient with hemothorax may experience chest pain, tachypnea, and mild to severe dyspnea, depending on the amount of blood in the pleural cavity and associated pathology. If respiratory failure results, the patient may appear anxious, restless, possibly stuporous, and cyanotic; marked blood loss produces hypotension and shock.