Hemothorax Clinical Presentation

Trauma or recent surgical intervention is usually self-evident.^[24] Occasionally, a hemorrhagic diathesis such as hemorrhagic disease of the newborn or Henoch-Schönlein purpura can lead to spontaneous hemothorax.^{[12, 11]} Internal thoracic artery rupture has been reported in association with Ehlers-Danlos syndrome. A few patients with spontaneous pneumothorax develop hemothorax.^{[25, 20]}

Chest pain and dyspnea are common symptoms. Symptoms and physical findings associated with hemothorax in trauma vary widely depending on the amount and rapidity of bleeding, the existence and severity of underlying pulmonary disease, the nature and degree of associated injuries, and the mechanism of injury.

Hemothorax in conjunction with pulmonary infarction is usually preceded by clinical findings associated with pulmonary embolism.

Catamenial hemothorax is an unusual problem related to thoracic endometriosis. Hemorrhage into the thorax is periodic, coinciding with the patient's menstrual cycle.

Tachypnea is common; shallow breaths may be noted. Findings include diminished ipsilateral breath sounds and a dull percussion note.

If substantial systemic blood loss has occurred, hypotension and tachycardia are present. Respiratory distress reflects both pulmonary compromise and hemorrhagic shock. Children may have traumatic hemothorax without bony fractures of the chest wall.

Blunt chest-wall injuries

Hemothorax is rarely a solitary finding in blunt trauma. Associated chest wall or pulmonary injuries are nearly always present.

Simple bony injuries consisting of one or multiple rib fractures are the most common blunt chest injuries. A small hemothorax may be associated with even single rib fractures but often remains unnoticed during the physical examination and even after chest radiography. Such small collections rarely need treatment.

Complex chest wall injuries are those in which either 4 or more sequential single rib fractures are present or a flail chest exists. These types of injuries are associated with a significant degree of chest wall damage and often produce large collections of blood within the pleural cavity and substantial respiratory impairment. Pulmonary contusion and pneumothorax are commonly associated injuries.

Injuries resulting in laceration of intercostal or internal mammary arteries may produce a hemothorax of significant size and significant hemodynamic compromise. These vessels are the most common source of persistent bleeding from the chest after trauma.

Delayed hemothorax can occur at some interval after blunt chest trauma. In such cases, the initial evaluation, including chest radiography, reveals findings of rib fractures without any accompanying intrathoracic pathology. However, hours to days later, a hemothorax is seen. The mechanism is believed to be either rupture of a trauma-associated chest wall hematoma into the pleural space or displacement of rib fracture edges with eventual disruption of intercostal vessels during respiratory movement or coughing.

Blunt intrathoracic injuries

Large hemothoraces are usually related to injury of vascular structures. Disruption or laceration of major arterial or venous structures within the chest may result in massive or exsanguinating hemorrhage.

Hemodynamic manifestations associated with massive hemothorax are those of hemorrhagic shock. Symptoms can range from mild to profound, depending on the amount and rate of bleeding into the chest cavity and the nature and severity of associated injuries.

Because a large collection of blood will compress the ipsilateral lung, related respiratory manifestations include tachypnea and, in some cases, hypoxemia.

A variety of physical findings such as bruising, pain, instability or crepitus upon palpation over fractured ribs, chest wall deformity, or paradoxical chest wall movement may lead to the possibility of coexisting hemothorax in cases of blunt chest wall injury.

Dullness to percussion over a portion of the affected hemithorax is often noted and is more commonly found over the more dependent areas of the thorax if the patient is upright. Decreased or absent breath sounds upon auscultation are noted over the area of hemothorax.

Penetrating trauma

Hemothorax from penetrating injury is most commonly caused by direct laceration of a blood vessel. While arteries of the chest wall are most commonly the source of hemothorax in penetrating injury, intrathoracic structures, including the heart, should also be considered.

Pulmonary parenchymal injury is very common in cases of penetrating injury and usually results in a combination of hemothorax and pneumothorax. Bleeding in these cases is usually self-limited.^[26]

Clinical caveats in traumatic hemothorax

Positive physical findings noted by percussion and auscultation are best appreciated in the upright patient and, even then, may be subtle. As much as 400-500 mL of blood may obliterate only the space comprising the costophrenic angle.

Many trauma victims are initially examined in the supine position. In such cases, a collection of blood within the pleural space will not occupy the diaphragmatic surface, but will be distributed along the entire posterior aspect of the affected pleural space. Physical examination techniques such as percussion and auscultation may produce equivocal findings even though a substantial collection of blood is present.

A hemothorax found in association with a diaphragmatic injury in either penetrating or blunt trauma may actually have its origin from an intra-abdominal source. Blood from injured abdominal organs may traverse a diaphragmatic tear and enter the thoracic cavity. In cases of hemothorax with diaphragmatic injury, the clinician should strongly consider the possibility of intra-abdominal injury.^[27]

Nontraumatic hemothorax

Symptoms and physical findings are variable, depending on the underlying pathology.

Hemothorax secondary to acute hemorrhage from structures within the chest can produce profound hemodynamic changes and symptoms of shock. Massive hemothorax can result from vascular structures such as a ruptured or leaking thoracic aortic aneurysm or from pulmonary sources such as lobar sequestration or arteriovenous malformation. Disruption of a vascular pleural adhesion unrelated to trauma can produce a significant hemothorax with an associated spontaneous pneumothorax.

Occult hemorrhage is most commonly related to metastatic disease or complications of anticoagulation. In these situations, bleeding into the pleural cavity occurs slowly, resulting in subtle or absent changes in hemodynamics. When the effusion is large enough to produce symptoms, dyspnea is usually the most prominent complaint. Signs of anemia may also be present. Physical examination reveals findings similar to those for any pleural effusion, with dullness to percussion and decreased breath sounds noted over the area of the effusion.