Description

Thoracic trauma has significant morbidity and mortality. It is the fourth most common trauma site after the head, abdomen, pelvis and extremities.

Thoracic trauma is one of the critical injury mechanisms in multiply injured trauma victims. Although these patients present a plethora of potential structural damages to vital organs, it remains debated which injuries actually influence outcome and thereby should be addressed initially.

Routine tests for chest injuries include chest X-rays and computed tomography (CT) scans. Chest X-rays are available but are insufficiently sensitive for chest trauma. Multi-detector CT is now considered the gold standard imaging tool in the emergency department; however, it is not applicable for unstable patients and is unavailable in intensive care units, so patient transport to radiology departments is required. This technique also exposes patients to high doses of ionizing radiation.

In thoracic trauma cases, ultrasonography of the lungs is valuable for evaluating various chest diseases, including chest wall hematoma and fractures, pleural cavity involvement with pleural effusion, hemothorax, and pneumothorax, and pericardial cavity involvement with hemopericardium.

The ultrasound can also assess the reduce in lung aeration in acute diseases by changing the lung surface and generating distinct patterns as in pulmonary contusions and compression atelectasis.

In pneumothorax cases, the major criterion for ultrasound diagnosis is the absence of lung sliding during a dynamic examination, as well as the absence of a pleural gap and lung point, which is the transitional area between the breath-dependent, moving lung and the pleural air column in cases of partial pneumothorax with incomplete lung collapse.

Lung contusion is the most frequent thoracic injury in blunt chest trauma and it is associated with increased morbidity and mortality. Direct damage of the lung tissue causes both local and systemic inflammatory responses that can lead to acute respiratory distress syndrome (ARDS) and multiple organ failure. The initial size of the lung contusion seems to play a key role in these mechanisms.Several CT scan studies have shown that initial lung contusion volume is predictive of the development of subsequent ARDS.

Ultrasounds aids in pleural effusion detection, even if minimal. Ultrasound can assess and quantify the amount of effusion, and characterize its internal complexity, such as septations, exudative effusion, fibrin strands, and echogenic pleural effusion.