A hemothorax is a serious medical condition involving the chest cavity that requires immediate attention. It is most frequently the result of an injury, but it can also arise from other medical problems. Rapid identification and proper treatment are important for patient outcome.
What Exactly Is a Hemothorax?
Hemothorax is the medical term for the presence of blood within the pleural space, the thin, fluid-filled area surrounding the lungs. Normally, this space is a potential cavity between the visceral pleura covering the lung and the parietal pleura lining the chest wall. The small amount of fluid allows the lungs to expand and contract smoothly during breathing.
When blood accumulates, it is defined as a hemothorax if the fluid’s hematocrit is at least 50% of the patient’s circulating blood hematocrit. The increasing blood volume exerts pressure on the lung, preventing full inflation and impairing breathing. A significant collection of blood can also lead to life-threatening hypovolemic shock due to massive blood loss into the chest cavity.
Traumatic and Non-Traumatic Causes
The most common origin of a hemothorax is trauma to the chest, categorized as either penetrating or blunt. Penetrating injuries, such as stabbings or gunshot wounds, violate the chest wall and can lacerate major blood vessels or lung tissue, leading to a sudden accumulation of blood. Blunt trauma, often seen in motor vehicle accidents or significant falls, can cause rib fractures whose jagged ends may tear intercostal arteries or pulmonary tissue.
Non-traumatic, or spontaneous, causes are less frequent. These include certain medical procedures, known as iatrogenic causes, such as the placement of a central venous catheter. Other origins involve underlying disease, including malignancies like lung cancer or tumors of the chest wall, which can damage local blood vessels. Conditions affecting blood clotting, such as coagulopathies or the use of anticoagulant medications, also increase the risk of bleeding into the pleural space.
Key Signs and Symptoms
The presentation of a hemothorax is determined by the volume and speed of blood accumulation. Patients often experience acute shortness of breath (dyspnea) because the compressed lung cannot fully expand. This respiratory distress is accompanied by rapid, shallow breathing (tachypnea) as the body attempts to compensate for reduced oxygen intake.
Chest pain is a common complaint, often described as sharp or a feeling of heaviness. If the bleeding is substantial, signs of systemic shock may develop rapidly, including a rapid heart rate (tachycardia) and low blood pressure (hypotension). Patients may also appear pale and clammy, reflecting poor circulation, and report restlessness and anxiety.
Diagnosis and Medical Management
Medical professionals begin diagnosis with a physical examination, often noting decreased or absent breath sounds and a dull sound when tapping (percussing) the chest wall. Initial confirmation is typically done with a chest X-ray, which can detect blood collections greater than about 175 to 200 milliliters. In trauma settings, a focused assessment with sonography for trauma (FAST exam) using ultrasound is often performed quickly to detect fluid.
A Computed Tomography (CT) scan is the preferred imaging method for a more detailed view of the blood collection and to identify the source of the bleeding. The standard initial management involves inserting a chest tube, a procedure called tube thoracostomy, which drains the blood from the pleural space. This drainage relieves pressure on the lung, allowing it to re-expand, and permits monitoring of the rate of ongoing blood loss.
The chest tube remains in place until the lung is fully re-expanded and the fluid drainage slows significantly. If the initial drainage exceeds 1,500 milliliters of blood, or if the bleeding continues rapidly (150 to 200 milliliters per hour for several hours), surgical intervention is necessary. This management may involve a video-assisted thoracoscopic surgery (VATS), a minimally invasive approach used to stop bleeding and remove blood clots. In severe cases of uncontrolled bleeding or unstable patients, a traditional open chest surgery, known as a thoracotomy, may be required to directly repair the damaged vessel.