Hemothorax

Definition of hemothorax

Distinctive - albeit not exclusive - sign of a perforating thoracic trauma, it is defined hemothorax any bleeding into the pleural cavity. Hemothorax constitutes a medical emergency in all respects: considering that the resulting clinical picture is often marked by a state of shock, it is clear that hemothorax constitutes a high risk for the survival of the victim.
Ideally, the pleural cavity can contain up to 2500-3000 ml of fluid: according to this, it is understandable how hemothorax can be a significant source of blood loss. If blood accumulates in the pleural cavity, the circulating blood volume is reduced: this "displacement" of blood is considered much more serious than a possible collapse of the lung induced by hemothorax. The video below, albeit in English, gives a very good idea of ​​how a hemothorax is formed following displaced rib fractures, and what its consequences are on respiratory mechanics.

Causes and risk factors

Contrary to popular belief, not all forms of hemothorax are an expression of piercing trauma. Two types of hemothorax have therefore been identified:

1. Traumatic hemothorax: it is the most recurrent variant, typical consequence of closed trauma (bruises, chest compression, fractures, dislocations) or perforating wounds (penetrating injuries and piercing wounds, generally associated with lesions of the lung parenchyma). Sometimes, incorrect placement of a central venous catheter can generate hemothorax. When air and bloody pleural fluid accumulate in the pleural cavity, it is called hemo-pneumothorax.
2. Non-traumatic hemothorax: the effusion of blood in the pleural cavity does not depend on injury or trauma. This variant is mainly related to changes in blood pressure, pulmonary cysts, blood clotting defects, hemopathies, bullous emphysema, pulmonary infarction, ruptured aneurysm, tuberculosis and tumors (eg pleural cancer).

Traumatic hemothorax

Non-traumatic hemothorax

1. Closed trauma

• Bruises
• chest compression
• fractures
• dislocations

2. Piercing wounds

• penetrating injuries
• piercing wounds

+ lesions of the lung parenchyma

• incorrect positioning of the central venous catheter

• alteration of blood pressure values
• lung cysts
• blood clotting defects
• hemopathies
• bullous emphysema
• pulmonary infarction
• rupture of an aneurysm
• tuberculosis
• tumors (e.g. pleural cancer).

Hemothorax: symptoms

The symptom picture caused by hemothorax differs more or less significantly according to the triggering factor. NON-traumatic hemothorax is always accompanied by chest pain, breathing difficulties, tachycardia and paleness (the latter three signs are characteristic of an anemic status). The traumatic variant is characterized by a much more complex picture, in which signs and symptoms of a different nature coexist. Generally speaking, the most common symptoms are:

• alteration of blood pressure values
• mood alteration / irritability
• anxiety
• cyanosis
• collapse of the lung
• tracheal deviation in correspondence with the healthy hemithorax (mid-thorax)
• dyspnea
• subcutaneous emphysema
• severe chest pain
• shortness of breath
• cold, clammy skin
• reduction of the sound of breathing in the affected hemithorax

Diagnosis

Hemothorax is suspected in the presence of pleural effusion with reddish veins. When the pleural effusion fluid appears bloody, it is essential to proceed with the measurement of the hematocrit value of the pleural fluid. The suspicion of hemothorax is confirmed when the hematocrit is> 50% compared to peripheral blood. In such circumstances, immediate chest drainage is required.
Chest radiography, CT and exploratory thoracentesis are other possible diagnostic strategies used to confirm or not the hemothorax. From reading the tests, it is possible to verify the extent and nature of the payment.

Care

A hemothorax visible on radiological examination justifies the instillation of a drain.
The main objectives of hemothorax therapy are, first of all, stopping the bleeding and replenishing the blood volume. The prevention of relapses and complications, as well as the re-expansion of the lung in a short time are other fundamental principles that must be achieved as soon as possible.
In the case of massive hemothorax, the option of a blood transfusion must be considered: in such circumstances, constant monitoring of the patient is recommended. For hemothorax with a spread equal to or greater than 1500 ml, an emergency thoracotomy is conceivable: this procedure frees the pleural cavity, stops bleeding and allows re-expansion of the lung. Clearly, emergency surgery for hemothorax must be performed with a view to also preventing possible complications, such as empyema and fibrothorax.