Hemothorax - Causes, Symptoms, Diagnosis, and Management

Introduction

A hemothorax is sometimes described as pleural fluid with a hematocrit greater than or equal to 50 % of the hematocrit of peripheral blood. Traumatic thoracic injuries frequently result in hemothorax. It is a buildup of blood in the pleural space, which could be found between the parietal and visceral pleura. The most frequent trauma mechanism is an injury to intrathoracic or extrathoracic structures by blunt or piercing objects that cause bleeding into the thorax. Bleeding can occur from the chest wall, internal or external mammary arteries, great vessels, mediastinum, myocardium, lung parenchyma, diaphragm, or abdomen.

What Are the Causes of Hemothorax?

Typically, it results from blunt or penetrating chest trauma (traumatic hemothorax). However, an unintentional hemothorax, also known as a spontaneous hemothorax, can happen. These circumstances include:

Thoracic Wall Tumors - Frequently co-occur with intrathoracic malignancy.

1. Schwannomas on the thoracic wall.

2. Neurofibromas on the thoracic wall.

3. Soft tissue growths.

Sarcomas: Angiosarcomas in the thorax.

1. Thoracic metastases or thoracic invasion in hepatocellular carcinomas.

2. Even in pleural extension, lung cancer is a remarkably uncommon cause of hemothorax.

Spontaneous Pneumothorax - Spontaneous hemopneumothorax.

1. Anticoagulant medication.

Vascular Rupture

1. Aortic dissection.

2. Rupture of coronary arteries such as RCA (right coronary artery) during an angioplasty.

3. Thoracic arteriovenous malformations

Pulmonary Arteriovenous Malformation.

• Thoracic endometriosis (a condition where tissue similar to the lining of the uterus (endometrial tissue) grows in the chest cavity).

• Pulmonary infarction (blood clot blocks the blood supply to a part of the lung, leading to tissue death due to lack of oxygen).

• Pleural adhesions with pneumothorax (scar-like tissue formations between the lung and the chest wall lining or pleura).

Hematologic Abnormalities: Disorders of the blood and blood-forming tissues

• Coagulopathy.
• Hemophilia.

Connective Tissue Disease:

• Ehlers-Danlos syndrome (EDS) type IV: has been associated with hemothorax.

Congenital bony exostoses.

What Is the Pathophysiology of Hemothorax?

Diaphragmatic, mediastinal, pulmonary, pleural, chest wall, and abdominal injuries can all result in bleeding into the hemithorax. 40 % of a patient's circulating blood volume can fit in each hemithorax. Injuries to intercostal vessels, such as those to the pulmonary vessels and internal mammary arteries, have been linked to severe bleeding that necessitates invasive treatment, according to studies. Hemodynamic and respiratory components make up the initial physiological response to a hemothorax. The severity of the pathophysiologic response depends on

• The location of the injury.

• The patient's functional reserve.

• The amount of blood.

• The rate at which it accumulates in the hemithorax.

Acute hypovolemia causes a drop in preload, left ventricular dysfunction, and a decrease in cardiac output during the initial reaction. By causing anatomic shunting, V/Q mismatch, and alveolar hypoventilation, blood in the pleural space impacts the lung's ability to function. A big hemothorax can increase hydrostatic pressure, impairing preload and raising pulmonary vascular resistance. These mechanisms result from tension.

What Are the Symptoms of Hemothorax?

The common symptoms of hemothorax are

• Breathing difficulty.

• Shallow, rapid breathing.

• Chest pain.

• Reduced blood pressure (shock).

• Clammy, chilly, and pale skin.

• Rapid heartbeat.

• Restlessness.

• Anxiety.

How Is Hemothorax Diagnosed?

Hemothorax is diagnosed based on physical findings and specific investigations and tests.

Physical Findings:

1. Distended Neck Veins - Pericardial tamponade, tension pneumothorax, cardiogenic failure, air embolism.

2. Seat Belt Sign - Deceleration or vascular injury; chest wall contusion or abrasion.

3. Flail Chest - Paradoxical chest wall movement.

4. Facial or Neck Swelling or Cyanosis - Superior mediastinum injury with occlusion or compression of superior vena cava (SVC).

5. Subcutaneous Emphysema - Torn bronchus or lung parenchyma laceration.

6. Scaphoid Abdomen - Diaphragmatic injury with herniation of abdominal content into the chest.

7. Excessive Abdominal Movement With Breathing - Chest wall injury.

Breath Sounds - Decreased or absent breath sounds on the affected side.

1. Plain Radiograph - A big hemothorax's chest radiographic appearance could resemble a pleural effusion. The most sensitive projection is the lateral decubitus, which can detect even minute amounts of fluid. Supine projections, on the other hand, can disguise a lot of fluid.

2. Ultrasound - For the diagnosis of hemothorax in the context of prior trauma, ultrasound offers exceptionally high sensitivity (92 %), specificity (100 %), positive predictive values (100 %), and negative predictive values (98 %), Although not specific, sonographic characteristics of hemothoraces include:

3. Echogenic Effusion That Is Uniform - This is typical of acute hemothoraces.

   1. Signs of Plankton -"Plankton sign" describes slow, spinning dynamics that occasionally exhibit punctiform internal echoes that swirl and exhibit slow dynamics within an otherwise anechoic pleural effusion.

   2. Hematocrit indicator.

   3. Suggests that the collection has been around for a longer time.

      • The posterior costophrenic recess may contain the cellular component.

      • Establishing contact with the top anechoic layer.

4. CT (Computed Tomography) Scan - By evaluating the attenuation value, a CT scan can identify the type of pleural fluid present in a trauma situation. The attenuation of blood in the pleural space typically ranges from 35 to 70 HU (Hounsfield unit). Measuring pleural fluid attenuation should be standard in interpreting chest trauma CT to differentiate between acute blood and simple fluid.

5. Other Ancillary Symptoms - Pulmonary contusions and lacerations.

6. Thoracentesis - A procedure to drain fluid from the area between the pleura, or outer lung lining, and the chest wall.

7. Thoracostomy - A hollow plastic tube is inserted between the ribs and into the chest during thoracostomy to remove any fluid or air that may be present around the lungs.

How Is Hemothorax Managed?

The underlying etiology will determine the precise therapeutic approach. Drainage is typically done as part of symptomatic therapy.

1. Apply the ATLS (advanced trauma life support) protocol when doing the first resuscitation and managing a trauma patient. Every patient needs two large-bore IVs (intravenous) and a 12-lead EKG (electrocardiogram) and must be hooked up to a heart and oxygen monitor. Quick action is necessary for immediate life-threatening injuries, such as decompression needle thoracostomy, emergent tube thoracostomy for massive pneumothoraces, and first hemothorax care.

2. Most of the time, minimal blood accumulation in the pleural cavity (defined as less than 300 ml) does not need to be treated; the blood typically reabsorbs over several weeks. Operative intervention is often unnecessary if the patient is stable and experiencing little respiratory discomfort. Patients in this group can receive analgesics as necessary and be monitored with recurrent imaging at 4 to 6 hours and 24 hours.

3. When feasible, a tube thoracostomy should be placed after consulting with cardiothoracic or trauma surgery. It has been common to evacuate hemothoraces using 36 to 40 French chest tubes; however, this technique has come under question. According to recent studies, most surgeons utilize 32 to 36 French tubes. Prospective investigations show that using 28 to 32 French tubes for hemothorax evacuation in level I trauma centers had the same results.

4. The tube is positioned posteriorly, toward gravity-dependent fluid, in the fourth or fifth intercostal space between the anterior and mid-axillary line when using an aseptic method. Next, a water seal and suction are attached to the thoracostomy tube to enable quick drainage and avoid air leakage. Additionally, inserting a tube allows blood measurement to assess the need for surgical intervention.

5. The following conditions demand immediate anterior thoracotomy:

   • 1500 cc of blood is drained through the chest tube every 24 hours.

   • 300 to 500 ml/hour for two to four hours straight following the installation of the chest tube.

   • A chest wall or significant vessel damage.

   • Tamponade of the pericardium.

6. Thoracotomy enables quick evaluation of intrathoracic wounds and hemostasis.

7. When coagulopathy (bleeding disorder) occurs, the hemothorax should be adequately drained while considering the underlying condition. If the clinical patient condition allows, coagulation function should be corrected before surgical intervention.

8. Options for treating a clotted hemothorax include:

   • Video-Assisted Thoracoscopic Surgery (VATS) - The efficiency of video-assisted thoracoscopy for the treatment of retained hemothorax has been proven in numerous trials. The length of hospital stays and patient survival have improved as a result. The benefits of VATS include clear pleural cavity visualization, proper placement of a chest tube for effective bleeding management, removal of the retained clot, evacuation of post-traumatic empyemas, and decortication of those empyemas. Additionally, it offers a diagnosis of suspected diaphragmatic injuries, care for ongoing air leaks, and assessment of mediastinal injuries.

   • Intrapleural Fibrinolytic Therapy (IPFT) - Fibrinolytic medicines are injected into the intrapleural space to dissolve fibrinous clots and membranes, prevent fluid sequestration, and promote drainage.

What Are the Complications of Hemothorax?

The complications of hemothorax include

1. Due to thoracic ultrasonography

Tenderness at the site where the probe was inserted.

2. Massive hemothorax could result in

• Cardiovascular instability.

• Shock.

• Hypoxia.

• Death.

Misusing a chest tube could result in solid organ damage.

• Inadequate chest tube placement may result in insufficient hemothorax drainage, which encourages the development of empyema. According to studies, patients with post-traumatic retained hemothorax have an empyema rate of 26.8 %. The pleural space is where fibrin deposits cause a fibrothorax. An inflammatory layer within the pleural cavity brought on by improper hemothorax drainage prevents adequate lung expansion with the phenomenon called lung entrapment.

Conclusion

Traumatic hemothorax morbidity and death are related to the extent of the damage and the presence of late sequelae such as empyema and fibrothorax or trapped lung. An extended stay in the intensive care unit or hospital is possible for patients with retained hemothorax.