Definition and Overview
Hemothorax is a medical condition characterised by the buildup of blood in the pleural space located between the chest cavity and the lungs. The condition is commonly caused by blunt or penetrating trauma that causes the serous membrane to rupture. This causes the blood from the thorax to spill into the pleural space. As a result, the lungs are unable to expand, which leads to breathing difficulties.
Any injury to the chest wall is considered a medical emergency because it significantly increases the risk of serious infection that can threaten the patient’s life. Injuries to the chest wall also often lead to massive blood loss because each side of the thorax holds as much as two litres of blood (in average adults), which equates to 40% of a person’s blood volume.
A patient’s physiologic response to hemothorax is manifested in two major areas: respiratory and hemodynamic. The degree of hemodynamic response is dependent on the amount of blood loss. Patients who lose 30% of their blood volume are at risk of tachycardia (fast resting heart rate), tachypnea (abnormal or rapid breathing), and decreased pulse pressure. The severity of the symptoms also depends on other factors including organs injured, underlying pulmonary reserve, and severity of the injury.
Based on studies, the condition is more likely to occur in young adolescent males.
The most common cause of hemothorax is a penetrating injury to the heart, great vessels, lungs, or chest wall. This may be deliberate, accidental, or a complication of a medical examination or treatment (iatrogenic) such as thoracostomy tube and central venous catheter placement.
Less frequently, hemothorax can be caused by:
Benign or malignant tumours
Blood disorders, including complications of anticoagulation
Hereditary haemorrhagic telangiectasia
Endometriosis, if endometrial tissue implants on the pleural space (spontaneous hemothorax)
In various medical studies, the following disorders have been found to occasionally result in hemothorax:
Blood disease of the newborn
Beta-thalassemia/hemoglobin E disease
Depending on the severity of the condition, patients may not experience any hemothorax signs and symptoms. A very small hemothorax caused by a single rib fracture, for example, may go undetected and may even resolve on its own. However, traumatic hemothorax can lead to life-threatening complications, such as:
Abnormalities of oxygenation and ventilation
Bacterial contamination and septic shock, if the condition is left untreated
Decreased pulse pressure
Low blood pressure
Massive blood loss
Who to See and Types of Available Treatments
Patients suffering from traumatic hemothorax must be taken to a hospital emergency room for immediate medical attention. Their vital signs are then measured and monitored. Doctors also work fast to treat or manage as many symptoms as possible.
To assess the patient’s condition, doctors normally perform hemothorax x-ray or chest radiography. If doctors require more information to further assess the severity of the condition, additional imaging studies, such as ultrasonography and computed tomography (CT) scan, may also be performed. Pleural fluid analysis, which involves obtaining and checking a small sample of the pleural fluid for bacterial infection and viruses, is also done.
The primary goal of hemothorax treatment is to stabilise the patient by stopping the bleeding and draining excess blood and air in the pleural space. If the patient is displaying unstable hemodynamics or has serious penetrating injuries, doctors often administer oxygen and establish a large-bore intravenous line so blood transfusion can be carried out immediately.
Doctors decide on whether to perform surgical procedures based on a number of factors. These include the volume of lost blood, the patient’s overall hemodynamic state, and the amount of blood that needs to be replaced. Depending on these factors, doctors may perform the following procedures:
Tube thoracostomy drainage - This procedure involves making a small incision in the chest wall to drain excess blood in the pleural space. Up to 80% of traumatic hemothorax patients are successfully treated with this procedure, which means that they require no further treatment. Two weeks after the procedure, they undergo chest radiographs so doctors can assess the treated area.
Video-assisted thoracoscopic surgery (VATS) - VATS is a minimally invasive procedure used to identify and control the source of bleeding. It is associated with shorter hospital stays and fewer postoperative complications because it does not require a huge surgical incision. Instead, it is performed using 3-4 small cuts in the chest.
Thoracotomy - In some cases, thoracotomy is required. This refers to the process of making a surgical incision in the chest wall if VATS proved to be inadequate. It is the procedure of choice in critical situations and if diagnostic tests suggest injury to the great vessels and the heart. It is also performed immediately if there is a developing cardiac tamponade, massive hemothorax, air leak, and traumatic valvular injury. It can be performed to remove blood clots, to correct underlying medical conditions (such as malignant tumours), for resecting necrotic lung tissue, and for repairing vascular abnormalities such as aortic aneurysms.
Prior to performing any of the procedures listed above, patients are administered with anaesthetic agents as well as a dose of intravenous antibiotics to help prevent infection from developing.
The outlook for patients with hemothorax depends on the cause of the condition and other factors such as the amount of blood loss, whether the patient has other underlying conditions, and how quickly treatment is given.
Unless immediate medical treatment is obtained, patients face the risk of suffering from a collapsed lung, scarring of the pleural membrane, infection of the pleural fluid, and even death in severe circumstances.
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Light RW, Lee YCG. Pneumothorax, chylothorax, hemothorax, and fibrothorax. In: Broaddus VC, Mason RJ, Ernst JD, et al, eds. Murray & Nadel's Textbook of Respiratory Medicine. 6th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 81.