Hemothorax

Hemothorax is the presence of blood in the pleural space. The source of blood may be the chest wall, lung parenchyma, heart, or great vessels. Although some authors state that a hematocrit value of at least 50% is necessary to differentiate a hemothorax from a bloody pleural effusion, most do not agree on any specific distinction.

Hemothorax is usually a consequence of blunt or penetrating trauma. Much less commonly, it may be a complication of disease, may be iatrogenically induced,[1] or may develop spontaneously.[2]

Prompt identification and treatment of traumatic hemothorax is an essential part of the care of the injured patient. The upright chest radiograph is the ideal primary diagnostic study in the evaluation of hemothorax (see Workup). In cases of hemothorax unrelated to trauma, a careful investigation for the underlying source must be performed while treatment is provided.

Tube thoracostomy drainage is the primary mode of treatment. Video-assisted thoracoscopic surgery (VATS) may be used. Thoracotomy is the procedure of choice for surgical exploration of the chest when massive hemothorax or persistent bleeding is present. (See Treatment.)

Historical background

Hemorrhage from or within the chest has been detailed in numerous medical writings dating back to ancient times. While lesser forms of trauma were commonly treated in the ancient physician's daily practice, major injuries, especially those to the chest, were difficult to treat and often lethal.

By the 18th century, some treatment for hemothorax was available; however, controversy raged about its form. A number of surgeons, including John Hunter in 1794, advocated the creation of an intercostal incision and drainage of the hemothorax. Those of the opposing viewpoint believed that closure of chest wounds without drainage and other conservative forms of management of bloody collections in the chest were proper treatment.

While Hunter's method was effective in evacuating the hemothorax, the creation of an iatrogenic pneumothorax as a result of the procedure was associated with significant morbidity. On the other hand, wound closure or conservative management posed the possible risks of subsequent empyema with sepsis or persistent trapped lung with permanent reduction of pulmonary function.

Observing the advantages and dangers of both forms of therapy, Guthrie, in the early 1800s, gave credence to both viewpoints. He proposed the importance of early evacuation of blood through an existing chest wound; at the same time, he asserted that if bleeding from the chest persisted, the wound should be closed in the hope that existing intrathoracic pressure would halt the bleeding. If the desired effect was accomplished, he advised that the wound be reopened several days later for the evacuation of retained clotted blood or serous fluid.

By the 1870s, early hemothorax evacuation by trocar and cannula or by intercostal incision was considered standard practice. Not long after this, underwater seal drainage was described by a number of different physicians. This basic technique has remained the most common form of treatment for hemothorax and other pleural fluid collections to this day.[3]

Normally, the pleural space, which is between the parietal and visceral pleurae, is only a potential space. Bleeding into the pleural space may result from either extrapleural or intrapleural injury.

Extrapleural injury

Traumatic disruption of the chest wall tissues with violation of the pleural membrane can cause bleeding into the pleural cavity. The most likely sources of significant or persistent bleeding from chest wall injuries are the intercostal and internal mammary arteries. In nontraumatic cases, rare disease processes within the chest wall (eg, bony exostoses) can be responsible.

Intrapleural injury

Blunt or penetrating injury involving virtually any intrathoracic structure can result in hemothorax. Massive hemothorax or exsanguinating hemorrhage may result from injury to major arterial or venous structures contained within the thorax or from the heart itself. These include the aorta and its brachiocephalic branches, the main or branch pulmonary arteries, the superior vena cava and the brachiocephalic veins, the inferior vena cava, the azygos vein, and the major pulmonary veins.

Injury to the heart can produce a hemothorax if a communication exists between the pericardium and the pleural space.

Injury to the pulmonary parenchyma may cause hemothorax, but it is usually self-limited because pulmonary vascular pressure is normally low. Pulmonary parenchymal injury is usually associated with pneumothorax and results in limited hemorrhage.

Hemothorax resulting from metastatic malignant disease is usually from tumor implants that seed the pleural surfaces of the thorax.

Diseases of the thoracic aorta and its major branches, such as dissection or aneurysm formation, account for a large percentage of specific vascular abnormalities that can cause hemothorax. Aneurysms of other intrathoracic arteries such as the internal mammary artery have been described and are possible causes of hemothorax if rupture occurs.

A variety of unusual congenital pulmonary abnormalities, including intralobar and extralobar sequestration,[4] hereditary telangiectasia, and congenital arteriovenous malformations, can cause hemothorax.

Hemothorax can result from a pathologic process within the abdomen if blood escaping from the lesion is able to traverse the diaphragm through one of the normal hiatal openings or a congenital or acquired opening.

Bleeding into the pleural space can occur with virtually any disruption of the tissues of the chest wall and pleura or the intrathoracic structures. The physiologic response to the development of a hemothorax is manifested in two major areas: hemodynamic and respiratory. The degree of hemodynamic response is determined by the amount and rapidity of blood loss.

Hemodynamic response

Hemodynamic changes vary, depending on the amount of bleeding and the rapidity of blood loss. Blood loss of up to 750 mL in a 70-kg man should cause no significant hemodynamic change. Loss of 750-1500 mL in the same individual will cause the early symptoms of shock (ie, tachycardia, tachypnea, and a decrease in pulse pressure).

Significant signs of shock with signs of poor perfusion occur with loss of blood volume of 30% or more (1500-2000 mL). Because the pleural cavity of a 70-kg man can hold 4 L of blood or more, exsanguinating hemorrhage can occur without external evidence of blood loss.

Respiratory response

The space-occupying effect of a large accumulation of blood within the pleural space may hamper normal respiratory movement. In trauma cases, abnormalities of ventilation and oxygenation may result, especially if associated with injuries to the chest wall.

A large enough collection of blood causes the patient to experience dyspnea and may produce the clinical finding of tachypnea. The volume of blood required to produce these symptoms in a given individual varies depending on a number of factors, including organs injured, severity of injury, and underlying pulmonary and cardiac reserve.

Dyspnea is a common symptom in cases in which hemothorax develops in an insidious manner, such as those secondary to metastatic disease. Blood loss in such cases is not so acute as to produce a visible hemodynamic response, and dyspnea is often the predominant complaint.

Physiologic resolution of hemothorax

Blood that enters the pleural cavity is exposed to the motion of the diaphragm, the lungs, and other intrathoracic structures. This results in some degree of defibrination of the blood so that incomplete clotting occurs. Within several hours of cessation of bleeding, lysis of existing clots by pleural enzymes begins.

Lysis of red blood cells results in a marked increase in the protein concentration of the pleural fluid and an increase in the osmotic pressure within the pleural cavity. This elevated intrapleural osmotic pressure produces an osmotic gradient between the pleural space and the surrounding tissues that favors transudation of fluid into the pleural space. In this way, a small and asymptomatic hemothorax can progress into a large and symptomatic bloody pleural effusion.

Late physiologic sequelae of unresolved hemothorax

Two pathologic states are associated with the later stages of hemothorax: empyema and fibrothorax. Empyema results from bacterial contamination of the retained hemothorax. If undetected or improperly treated, this can lead to bacteremia and septic shock.

Fibrothorax results when fibrin deposition develops in an organized hemothorax and coats both the parietal and visceral pleural surfaces. This adhesive process traps the lung in position and prevents it from expanding fully. Persistent atelectasis of portions of the lung and reduced pulmonary function result from this process.

By far the most common cause of hemothorax is trauma. Penetrating injuries of the lungs, heart, great vessels, or chest wall are obvious causes of hemothorax; they may be accidental, deliberate, or iatrogenic in origin.[5] In particular, central venous catheter and thoracostomy tube placement are cited as primary iatrogenic causes.[6, 7, 8]

Blunt chest trauma can occasionally result in hemothorax by laceration of internal vessels.[9] Because of the relatively more elastic chest wall of infants and children, rib fractures may be absent in such cases.[10, 11]

The causes of nontraumatic or spontaneous hemothorax include the following:

• Neoplasia (primary or metastatic)
• Blood dyscrasias, including complications of anticoagulation
• Pulmonary embolism with infarction
• Torn pleural adhesions in association with spontaneous pneumothorax
• Bullous emphysema
• Necrotizing infections
• Tuberculosis
• Pulmonary arteriovenous fistulae
• Hereditary hemorrhagic telangiectasia ^[12]
• Nonpulmonary intrathoracic vascular pathology (eg, thoracic aortic aneurysm or aneurysm of the internal mammary artery)
• Intralobar and extralobar sequestration ^[4]
• Abdominal pathology (eg, pancreatic pseudocyst, splenic artery aneurysm, or hemoperitoneum)
• Catamenial ^[13]

Case reports involve associated disorders such as hemorrhagic disease of the newborn (eg, vitamin K deficiency), Henoch-Schönlein purpura, and beta thalassemia/hemoglobin E disease.[14, 15, 16, 17] Congenital cystic adenomatoid malformations occasionally result in hemothorax.[18] A case of massive spontaneous hemothorax has been reported with Von Recklinghausen disease.[19] Spontaneous internal thoracic artery hemorrhage was reported in a child with type IV Ehlers-Danlos syndrome.

Hemothorax has also been reported in association with costal cartilaginous anomalies.[20, 21, 22, 23] Rib tumors have rarely been reported in association with hemothorax. Intrathoracic rupture of an osteosarcoma of a rib caused hemorrhagic shock in a 13-year-old girl.[24]

Hemothorax has been noted to complicate a small fraction of spontaneous pneumothorax cases. Although rare, it is more likely to occur in young adolescent males and can be life-threatening secondary to massive bleeding.[25]

Quantifying the frequency of hemothorax in the general population is difficult. A very small hemothorax can be associated with a single rib fracture and may go undetected or require no treatment. Because most major hemothoraces are related to trauma, a rough estimate of their occurrence may be gleaned from trauma statistics.

Approximately 150,000 deaths occur from trauma each year. Approximately three times this number of individuals are permanently disabled because of trauma, and the majority of this combined group have sustained multiple trauma. Chest injuries occur in approximately 60% of multiple-trauma cases; therefore, a rough estimate of the occurrence of hemothorax related to trauma in the United States approaches 300,000 cases per year.[26]

In a 34-month period at a large level-1 trauma center, 2086 children younger than 15 years were admitted with blunt or penetrating trauma; 104 (4.4%) had thoracic trauma.[27] Of the patients with thoracic trauma, 15 had hemopneumothorax (26.7% mortality), and 14 had hemothorax (57.1% mortality). Many of these patients had other severe extrathoracic injuries. Nontraumatic hemothorax carries a much lower mortality.

In another series of children with penetrating chest injuries (ie, stab or gunshot wounds), the morbidity was 8.51% (8 of 94).[28] Complications included atelectasis (3), intrathoracic hematoma (3), wound infection (3), pneumonia (2), air leak for more than 5 days (2), and septicemia (1). Note that these statistics apply only to traumatic hemothorax.

At present, the general outcome for patients with traumatic hemothorax is good. Mortality associated with cases of traumatic hemothorax is directly related to the nature and severity of the injury. Morbidity is also related to these factors and to the risks associated with retained hemothorax, namely empyema and fibrothorax/trapped lung. Empyema occurs in approximately 5% of cases. Fibrothorax occurs in about 1% of cases.

Retained hemothorax with or without one of the aforementioned complications occurs in 10-20% of patients who sustain a traumatic hemothorax, and most of these patients require evacuation of this collection. Prognosis after the treatment of one of these complications is excellent.

Short-term and long-term outcome for individuals who develop a nontraumatic hemothorax is directly related to the underlying cause of the hemothorax.

Trauma or recent surgical intervention is usually self-evident.[29] Occasionally, a hemorrhagic diathesis, such as hemorrhagic disease of the newborn or Henoch-Schönlein purpura, can lead to spontaneous hemothorax.[16, 15] Internal thoracic artery rupture has been reported in association with Ehlers-Danlos syndrome. A few patients with spontaneous pneumothorax develop hemothorax.[30, 25]

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 four 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. Although 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.[31]

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.[32]

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.

Upright chest radiography is the ideal primary diagnostic study in the evaluation of hemothorax. Additional imaging studies, such as ultrasonography and computed tomography (CT), may sometimes be required for identification and quantification of a hemothorax noted on a plain chest radiograph.

In some cases of nontraumatic hemothorax, especially those resulting from metastatic pleural implants, patients may present with the finding of a new pleural effusion of unknown etiology, and hemothorax may not be identified until the initial diagnostic needle aspiration is performed.

Measurement of the hematocrit of pleural fluid is virtually never needed in a patient with a traumatic hemothorax, but may be indicated for the analysis of a bloody effusion from a nontraumatic cause. In such cases, a pleural effusion with a hematocrit value more than 50% of that of the circulating hematocrit is considered a hemothorax.

Plain radiography of the upright chest may be adequate to establish diagnosis by showing blunting at the costophrenic angle or an air-fluid interface if a hemopneumothorax is present. (See the image below.) If the patient cannot be positioned upright, a supine chest radiograph may reveal apical capping of fluid surrounding the superior pole of the lung. A lateral extrapulmonary density may suggest fluid in the pleural space.

In the normal unscarred pleural space, a hemothorax is noted as a meniscus of fluid blunting the costophrenic angle or diaphragmatic surface and tracking up the pleural margins of the chest wall when viewed on the upright chest x-ray film. This is essentially the same chest radiographic appearance found with any pleural effusion.

In cases in which pleural scarring or symphysis is present, the collection may not be free to occupy the most dependent position within the thorax, but will fill whatever free pleural space is available. This situation may not create the classic appearance of a fluid layer on a chest radiograph.

In the acute trauma setting, the portable supine chest radiograph may be the first and only view available from which to make definitive decisions regarding therapy. The presence and size of a hemothorax is much more difficult to evaluate on supine films. Although as much as 400-500 mL of blood is required to obliterate the costophrenic angle on an upright chest radiograph, as much as 1000 mL of blood may be missed when viewing a portable supine chest x-ray film. Only a general haziness of the affected hemithorax may be noted.

In blunt trauma cases, hemothorax is frequently associated with other chest injuries visible on the chest radiograph, such as rib fractures (see the image below), pneumothorax, or a widening of the superior mediastinum.

Trauma ultrasonography is used at some trauma centers in the initial evaluation of patients for hemothorax. Even with the use of chest radiography and helical CT, some injuries can remain undetected. In particular, patients with penetrating chest injuries may harbor serious cardiac injury and a pericardial effusion that may be clinically difficult to determine. Bedside echocardiography can provide immediate, accurate information regarding the pericardium and the need for immediate surgery. It can also improve patient outcome.[33]

One drawback of ultrasonography for the identification of traumatic hemothorax is that associated injuries readily seen on chest radiographs in the trauma patient, such as bony injuries, widened mediastinum, and pneumothorax, are not readily identifiable on chest ultrasonograms. Ultrasonography more likely plays a complementary role in specific cases where the chest x-ray findings of hemothorax are equivocal.

Thoracic CT (see the image below) has a definite role to play in evaluation of hemothorax, particularly if plain radiography results are ambiguous or initial therapy is inadequate.[34, 35] CT is a highly accurate diagnostic study for pleural fluid or blood and is particularly helpful in localizing loculated collections of blood.

In the trauma setting, CT does not play a primary role in the diagnosis of hemothorax but is complementary to chest radiography. Because many victims of blunt trauma do undergo evaluation with chest CT, abdominal CT, or both, hemothorax not evident on initial chest radiographs might be identified and treated.

Currently, CT is of greatest value later in the course of management of the chest trauma patient, in particular for localization and quantification of any retained collections of clot within the pleural space.

Although multidetector CT allows for the accurate diagnosis of most traumatic injuries, in pediatric patients it should be used in selected cases only. Routine use would result in an unacceptably high radiation exposure to a large number of patients without proven clinical benefit.[36]

Blood in the pleural space can be associated with both hemorrhagic shock and respiratory compromise. It must be effectively evacuated to prevent complications such as fibrothorax and empyema.

If chest radiography shows that a hemothorax is large enough to obscure the costophrenic sulcus or is associated with a pneumothorax, it should be drained by tube thoracostomy. In cases of hemopneumothorax, placement of two chest tubes may be preferred, with the tube draining the pneumothorax placed in a more superior and anterior position.

Surgical exploration in cases of traumatic hemothorax should be performed in the following circumstances:

• Evacuation of more than 1000 mL of blood immediately after tube thoracostomy; this is considered a massive hemothorax
• Continued bleeding from the chest, defined as 150-200 mL/hr for 2-4 hours
• Repeated blood transfusion is required to maintain hemodynamic stability

The late sequelae of hemothorax, including residual clot, infected collections, and trapped lung, require additional treatment and, most often, surgical intervention.

Retained clot (defined as an undrained collection of 500 mL or more as estimated by computed tomography [CT] or opacification of one third or more of the chest on chest radiography) is a well-known sequela after initial tube thoracostomy for hemothorax and should be evacuated early in the patient's hospital course, if the clinical condition permits. Early intervention in the case of a retained clot can be performed with thoracoscopy, provided that the operation is planned within 1 week of the bleeding episode.

Empyema usually develops from superimposed infection in a retained collection of blood. It requires surgical drainage and, possibly, decortication.

Fibrothorax is a late uncommon complication that can result from retained hemothorax. Thoracotomy and decortication are required for treatment.

Needle aspiration of a hemothorax is generally not indicated for definitive treatment. Even in cases of nontraumatic hemothorax that are not identified until diagnostic needle aspiration is performed, complete evacuation of these collections often requires treatment with tube thoracostomy, much as with hemothoraces resulting from other causes.

No data support routine antibiotic coverage of chest tubes in patients with hemothorax. Pain control may require intravenous opioid analgesic agents, intracostal nerve blocks around the chest tube site, or both. Low suction should be used on the chest tube.

Initial treatment is directed toward cardiopulmonary stabilization and evacuation of the pleural blood collection. The patient should be sitting upright unless other injuries contraindicate this position. Administer oxygen and reassess airway, breathing, and circulation. Obtain an upright chest radiograph as quickly as possible.

If the patient is hypotensive, establish a large-bore intravenous line. Immediately commence appropriate fluid resuscitation (eg, with 20 mL/kg of lactated Ringer solution), including blood transfusion as necessary.

Evaluate for the possibility of tension pneumothorax. Needle decompression of a tension pneumothorax may be necessary.

The need for a chest tube in an asymptomatic patient is unclear, but if the patient has any respiratory distress, perform thoracostomy. If a conventional chest tube is not removing the blood collection, further steps may be necessary. Conventional treatment involves placement of a second thoracostomy tube. However, in many patients, this therapy is ineffective, necessitating further intervention.

Tube thoracostomy drainage is the primary mode of treatment for hemothorax. In cases of trauma, patient assessment should be performed using the advanced trauma life support (ATLS) protocol before tube thoracostomy for hemothorax. (See the video below.)

This procedure is relatively contraindicated when significant pleural adhesions are known to be present. Incomplete drainage or inability to effectively access the area is likely. Also, blunt division of pleural adhesions may cause additional bleeding and result in lung laceration. If evacuation of such collections is mandated clinically, thoracotomy with division of adhesions under direct vision is the safer approach.

Drainage in patients with coagulopathy

Although not contraindicated, drainage of hemothorax or any pleural effusion in an individual with a coagulopathy should be performed with great care. This group includes patients receiving anticoagulation therapy and those with significant liver disease or inherited coagulation factor deficiencies. Normalization of coagulation function by cessation of anticoagulants or correction of factor deficiencies using appropriate blood products, if necessary, should be initiated before a drainage procedure, if possible.

Needle aspiration should not be performed if clotting deficiencies are present. Rather, tube thoracostomy should be used, with the ability to visualize and control any chest wall bleeding that is encountered. If necessary, in individuals requiring long-term anticoagulant therapy, this medication can be resumed 8-12 hours after the thoracostomy has been completed.

Equipment

A tube thoracostomy tray or kit should be readily available in every hospital emergency department. In adult patients, large-bore chest tubes (usually 36-42 French) should be used to achieve adequate drainage. Smaller-caliber tubes are more likely to occlude. In pediatric patients, chest tube size varies with the size of the child. In patients older than 12 years, the chest tube size used is usually the same as that for adults. In smaller children, a 24- to 34-French chest tube should be used, depending on the size of the child.

Procedure

Although tube thoracostomy may be performed rapidly in some circumstances, sterile technique should always be employed. The insertion site should also be infiltrated with a local anesthetic.

On insertion, the thoracotomy tube is directed toward the costophrenic angle. Attention should be given to the location of insertion on the chest wall and the intrathoracic position of the tube as seen on the chest radiograph. For maximum drainage, thoracostomy tube placement for hemothorax should ideally be in the sixth or seventh intercostal space at the posterior axillary line. In the supine trauma victim, a common error in chest tube insertion is placement too anteriorly and superiorly, making complete drainage very unlikely.

Follow-up

After tube thoracostomy is performed, a repeat chest radiograph should always be obtained immediately. This helps identify chest tube position, helps determine completeness of the hemothorax evacuation, and may reveal other intrathoracic pathology previously obscured by the hemothorax.

A chest tube is usually put to water seal after the lung is fully reexpanded on radiography, fluid drainage is less than 50 mL in 24 hours, and no significant residual air leak is present. Situations may exist when a chest tube must be clamped. When no recurrence of air or fluid collection occurs on follow-up radiographic studies, the tube is then usually removed. A postremoval radiograph should be obtained.

If drainage is incomplete as visualized on the postthoracostomy chest radiograph, placement of a second drainage tube should be considered. Preferably, a video-assisted thoracoscopic surgery (VATS) procedure should be undertaken to evacuate the pleural space.

As many as 70-80% of individuals who sustain traumatic hemothorax are successfully treated by tube thoracostomy drainage and require no further therapy. Obtain at least one or two additional chest radiographs over a period of 1-2 weeks to confirm that no further intrathoracic collections or abnormalities are present.

The need for further follow-up chest radiographs may be dictated by the presence of other intrathoracic pathology and by additional symptoms and physical findings. Further treatment or follow-up is determined by the nature of any other injuries.

Video-assisted thoracoscopic surgery (VATS) is an alternative treatment that permits direct removal of clot and precise placement of chest tubes. Several centers have used this modality successfully to help identify and control the source of bleeding in a number of cases.[37] In comparison with thoracostomy, VATS is associated with fewer postoperative complications and shorter hospital stays.

A 2015 review by Chou et al suggested that intervention by means of VATS for retained traumatic thorax is best done within 7 days.[38]  A subsequent systematic review and meta-analysis by Ziapour et al suggested that VATS should be considered within the first 3 days in this setting if it is the clinician's desired evacuation method.[39]

Thoracotomy is the procedure of choice for surgical exploration of the chest when massive hemothorax or persistent bleeding is present. At the time of surgical exploration, the source of bleeding is controlled and the hemothorax is evacuated.

Surgical exploration of the chest may be required later in the course of the patient with hemothorax for evacuation of retained clot, drainage of empyema, or decortication. Cases with retained clot can often be treated successfully with a VATS procedure, especially if this is accomplished within 7 days of initial drainage of the hemothorax, but thoracotomy is usually required for adequate empyema drainage or decortication.

In nontraumatic cases of hemothorax resulting from surgically correctable intrathoracic pathology, correction of the underlying disease process and evacuation of the hemothorax should be undertaken. This may include stapling or resection of bullous disease, resection of cavitary disease, resection of necrotic lung tissue, sequestration of arteriovenous malformations, or resection or repair of vascular abnormalities such as aortic aneurysms.[26]

The decision to perform surgical exploration in cases of hemothorax from acute trauma is based on a number of factors, including the volume and persistence of blood loss, the overall hemodynamic state of the patient, and the amount of blood replacement required. (See Approach Considerations.)

Volume resuscitation should be performed according to ATLS protocol and should be continued en route to the operating room. Some forethought must be given to the availability of blood products if needed rapidly.

Anesthesia should be started rapidly, and all maneuvers should be employed to prevent aspiration. Although a double-lumen endotracheal tube is a very useful luxury to have in thoracic surgical cases, it is only absolutely necessary in a few cases and should not be considered unless it can be placed without delaying the operative procedure. Standard endotracheal intubation is adequate in most cases.

At least two secure large-bore intravenous lines must be established before surgery so that fluids and blood products can be administered rapidly if needed. An arterial line should be placed, but central intravenous access is not an absolute necessity, and surgery should not be delayed for such procedures. Pulse oximetry and the end-tidal carbon dioxide value should be monitored during the procedure.

If stability of the spine or other skeletal structures has not been fully determined before exploratory thoracotomy, every effort must be made to maintain proper support and stabilization of these structures when positioning the patient for thoracotomy.

In hemodynamically unstable patients, volume resuscitation must be maintained during the administration of any anesthetic agents because further instability and hypotension may ensue with anesthesia induction.

A dose of intravenous antibiotics should be administered before emergency exploration. Generally, a broad-spectrum cephalosporin is advisable. If thoracoabdominal injury is present and bowel injury is considered, coverage for gastrointestinal tract organisms should be added.

Conservation of patient body temperature in trauma surgery is extremely important. A variety of surface-warming devices are available and can be used to cover the patient, leaving only the operative field open. Warmers should also be used for intravenous crystalloid and blood products. Raising the ambient temperature in the operating room may be necessary. Maintenance of body temperature is extremely important to prevent complications such as coagulopathy and cardiac arrhythmias.

Intraoperative details

In the majority of trauma cases necessitating chest exploration, the bleeding source is from the chest wall, most commonly intercostal or internal mammary arteries. Once identified, these can be easily controlled with suture ligatures in most cases. After control of obvious bleeding and evacuation of clot and blood, a rapid but thorough exploration of the entire chest cavity should be performed.

Unstable rib fractures found at the time of surgery may require some debridement of sharp rib edges to prevent further injury to the lung or adjacent chest wall structures. At some centers, flail segments or extensive rib fractures are stabilized with wires or other types of support in an attempt to improve postoperative chest wall mechanics.

A thoracic surgeon should be present or immediately available at the time of emergency thoracic exploration because control of bleeding from difficult areas such as the hilum of the lung, the heart, or the great vessels may require a surgeon with expertise in that field.

Patients with injuries between the level of the nipples and the umbilicus may have injuries in both the chest and abdomen. If surgical exploration is mandated, proper positioning, prepping, and draping of these patients is wise so that access to both cavities is possible.

With the patient prepared in this manner, an unanticipated abdominal bleeding source beneath a ruptured diaphragm found at the time of chest exploration for hemothorax can be addressed more easily. The chest can be rapidly explored to help rule out additional intrathoracic sources, and attention can then be quickly turned to abdominal exploration. This preparation also allows ready thoracic access for clamping the thoracic aorta if hemodynamic instability arises from massive or uncontrolled hemorrhage at the time of abdominal exploration.

Diaphragmatic injuries may be closed from either the thorax or the abdomen. In the acute trauma setting, it is usually closed from the abdomen.

Adequate drainage of the chest after control of bleeding is very important. Because chest drainage tubes are placed under direct vision, the complication of retained hemothorax should occur with extreme infrequency. A minimum of two large-bore chest tubes should be used, with one positioned posteriorly and the other positioned anteriorly. Some surgeons prefer the addition of a right-angled chest tube positioned over the diaphragm.

Postoperative details

Ventilator management should progress according to the individual status of the patient. In cases where no other significant injury or disease process is present, weaning and extubation may proceed in a routine fashion. In more critically ill patients such as those with severe chest wall injuries or those requiring massive transfusion, ventilator management must be tailored to the condition of the patient.

After extubation, pulmonary toilet and adequate pain control are critical in preventing pulmonary complications such as atelectasis and pneumonia.

Chest tubes are maintained on underwater seal suction, and the volume of drainage and air leak are noted and recorded daily. If pulmonary injury is found or resection of lung tissue is required at the time of surgery, chest tubes are not removed until any air leak has disappeared and the lung is fully expanded as viewed on the chest radiograph. Drainage should be less than 100 mL in 24 hours before chest tube removal.

Antibiotic coverage begun preoperatively should be discontinued after 48 hours unless a definite reason exists for continuance.

Ventilator management should progress according to the individual status of the patient. In cases in which no other significant injury or disease process is present, weaning and extubation may proceed in a routine fashion. In more critically ill patients, such as those with severe chest wall injuries or those requiring massive transfusion, ventilator management must be tailored to the condition of the patient. After extubation, pulmonary toilet and adequate pain control are critical in preventing pulmonary complications such as atelectasis and pneumonia.

Approximately 20% of patients who initially have tube thoracostomy for drainage of hemothorax will have some amount of residual clot in the thoracic cavity. Some controversy exists regarding the management of retained clot after tube thoracostomy. Opinions range from conservative watchfulness to additional chest tube placement to surgical evacuation. Current opinion seems to favor some form of clot evacuation.

Many trauma centers are moving away from additional tube thoracostomy and, instead, advocating an early VATS procedure. This is usually performed within 7-8 days of the initial injury and, in some centers, is performed within 48-72 hours if a retained clot is identified within the thorax.[40, 41, 42, 43] However, VATS may be successful even in patients presenting late after injury.[44]

For VATS evacuation of the hemothorax or retained clot, one-lung ventilation is not required. A single-lumen tube can be used with directions to the anesthesiologist to decrease tidal volume or intermittently hold ventilation during the procedure. If cardiac, great vessel, or tracheobronchial injury is found, conversion to thoracotomy can be performed expeditiously.

The decision to perform early evacuation of retained hemothorax with VATS technology is likely to greatly diminish the number of patients who develop the sequelae of empyema and fibrothorax. Although it adds an operative procedure to the patient's management, this approach provides definitive treatment while avoiding the morbidity of a formal thoracotomy, and it shortens the total hospital stay when compared with more conservative management methods.

Patients undergoing surgical intervention for retained hemothorax in either an acute or late setting are monitored in the same fashion as any patient who has undergone VATS or thoracotomy. Generally, the chest tube is removed when drainage is less than 100-150 mL in 24 hours. A chest radiograph is often obtained after removal. Additional chest x-rays films are obtained as previously noted. Care of the thoracic incision(s) is the same as for any thoracic surgical case.

If conservative management of retained collections is chosen, serial chest x-rays should be obtained to assure that resolution is occurring. Once the pleural collection has resolved, a recurrence is unlikely and the patient may be discharged. Increase in size of the collection, development of an air-fluid level, or the new onset of symptoms (eg, fever, cough, dyspnea, pleuritic pain) may warrant CT evaluation and reassessment for surgical intervention.

Intrapleural instillation of fibrinolytic agents is advocated in some centers for evacuation of residual hemothorax in cases in which initial tube thoracostomy drainage is inadequate. The proposed dose is 250,000 IU of streptokinase or 100,000 IU of urokinase in 100 mL of sterile saline.[45] Some centers prefer the use of tissue plasminogen activator (TPA).[46]

In a study of intrapleural fibrinolytic treatment of traumatic clotted hemothorax, daily instillations of fibrinolytic agents into the intrapleural the space for 2-15 days resulted in an overall success rate of 92%.[45] Nevertheless, the use of intrapleural instillation of fibrinolytic agents for the evacuation of hemothorax is not likely to become routine, because of the length of in-hospital time required for complete treatment and the risk of untoward effects.

Reexpansion pulmonary edema after evacuation of retained hemothorax is a rare reported complication. Associated factors in the development of this problem appear to be hypovolemia and the administration of large amounts of blood products and other volume expanders in the perioperative period.

Empyema can develop if a retained clot becomes secondarily infected. This can occur from associated pulmonary injuries or from external sources such as the penetrating object or missile that caused the original injury or the presence of a long-standing clotted thoracostomy tube.

Fibrothorax and trapped lung develop if fibrin deposition occurs within a clotted hemothorax. This can lead to persistent atelectasis and a reduction of pulmonary function. A decortication procedure may be necessary to permit lung expansion and reduce the risk of empyema.