hemothorax

Definition of hemothorax

A distinctive sign - albeit not exclusive - of a thoracic perforating trauma, is defined hemothorax as any blood spill in 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 evident that hemothorax constitutes a high risk for the survival of the victim.

Ideally, the pleural cavity can contain up to 2500-3000 ml of liquid: according to this, it is understandable how hemothorax can be a significant source of blood loss. If the blood accumulates in the pleural cavity, the circulating blood volume is reduced: this "movement" of blood is considered to be much more serious than a possible collapse of the lung induced by the hemothorax. The video below, although in English, gives a good idea of ​​how an hemothorax is formed following broken rib fractures, and what its consequences are on respiratory mechanics.

Causes and risk factors

Unlike what one might believe, not all forms of hemothorax are the expression of a perforating trauma. Two types of hemothorax have therefore been identified:

1. Traumatic hemothorax: it is the most recurrent variant, typical consequence of closed traumas (bruises, chest compression, fractures, dislocations) or perforating wounds (penetrating lesions 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, this is called emo-pneumothorax.
2. Non-traumatic hemothorax: the shedding of blood in the pleural cavity does not depend on injury or trauma. This variant is mainly related to alterations in blood pressure, pulmonary cysts, blood coagulation defects, blood disorders, bullous emphysema, pulmonary infarction, rupture of an aneurysm, tuberculosis and tumors (eg pleural cancer).

Hemothorax: symptoms

The symptomatic picture caused by the hemothorax differs in a more or less significant way based on the triggering factor. The non-traumatic hemothorax is always accompanied by chest pain, breathing difficulties, tachycardia and pallor (these last three signs are characteristic of an anemization status). The traumatic variant is characterized by a much more complex picture, in which signs and symptoms of different nature coexist. In general, the most common symptoms are:

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

Diagnosis

Hemothorax is suspected in the presence of pleural effusion with reddish veins. When the liquid of the pleural effusion 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 X-ray, CT and exploratory thoracentesis are other possible diagnostic strategies used for the confirmation or not of hemothorax. From the reading of 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 drainage.

The main goals of the hemothorax therapy are, above all, the arrest of hemorrhage and the reintegration of the volume. The prevention of recurrences and complications, as well as the re-expansion of the lung in a short time are other fundamental principles that must be reached as soon as possible.

In the case of imposing haemothorax, the option of a blood transfusion must be considered: in similar circumstances, constant monitoring of the patient is recommended. For hemothorax with spreading equal to or greater than 1500 ml, urgent thoracotomy is conceivable: this practice frees the pleural cavity, stops bleeding and allows re-expansion of the lung. Clearly, the emergency intervention for the hemothorax must be carried out with a view to also preventing possible complications, such as empyema and fibrothorax.