hemopneumothorax

Hemopneumothorax

Hemopneumothorax or less commonly haematopneumothorax or pneumohemothorax, is a term given when there is concurrent presence of a hemothorax (presence of blood in the pleural space) and pneumothorax (presence of air in the pleural space) 1). Hemopneumothorax is a variant of a hydropneumothorax. Approximately 5% of patients with pneumothorax will have concomitant hemothorax 2). Hemopneumothorax is typically seen in the setting of trauma (traumatic hemopneumothorax) and thoracic intervention (e.g., insertion of pacemakers, or in cases of pneumonectomy). Unlike in a pleural effusion with a lateral meniscus, when air and fluid is combined the appearances are perfectly straight in the horizontal plane due to the air-fluid level.

Tension pneumothorax is a one way valve effect which allows air to enter the pleural space, but not leave. Air and so intrapleural pressure (tension) builds up and forces a mediastinal shift. This leads to decreased venous return to the heart and lung collapse/compression causing acute life-threatening respiratory and cardiovascular compromise. Ventilated patients are particularly atrisk due to the positive pressure forcing more air into the pleural space. Tension pneumothorax results in rapid clinical deterioration and is an emergency.

Finger thoracostomy is the preferred method of emergency pleural decompression of a tension pneumothorax. Finger thoracostomy involves incising 3-4 cm of skin over the 4th intercostal space just anterior to the mid-axillary line followed by blunt dissection to the pleura to allow introduction of a finger into the pleural space.

With few exceptions, chest drain insertion follows immediately after finger thoracostomy, with the caveat that the time and place of insertion must be consistent with the patient’s overall clinical priorities. Finger thoracostomy should be accompanied by intubation and positive pressureventilationto ensureadequate ventilation despiteair entering the pleural cavity, and reduce the likelihood of re-accumulation of a tension pneumothorax due to entrainment of external air through an open thoracostomy site. To reduce the risk of empyema, these patients should receive broad spectrum intravenous antibioticcoverage, e.g. cephazolin with consideration for metronidazole if soiled.

In the exceptional situation that finger thoracostomy in emergency department is not immediately followed by drain insertion, it is imperative that a clear plan for delayed drain insertion is communicated to relevant staff to ensure this procedure is safely completed at the earliest opportunity.

Treatment for hemopneumothorax is exactly the same as for its separate states, by tube thoracostomy—the insertion of a chest drain through an incision made between the ribs, into the intercostal space. Commonly, surgery is needed to close off whatever injuries caused the bleeding into the lung cavity and also whatever injuries caused the air to enter the cavity (e.g stabbing, broken ribs, etc.)

Figure 1. Hemopneumothorax

hemopneumothorax

Footnote: A perfectly straight line traverses the lower left thoracic cavity due to a combination of fluid and air in the pleural space. Right lung clear.

Hemopneumothorax causes

Hemopneumothorax is typically seen in the setting of trauma (traumatic hemopneumothorax) but can rarely occur in non-traumatic situations including:

  • as a complication of cavitary pulmonary metastases 3)
  • as a complication of non-cavitary pulmonary metastases 4)
  • spontaneous: spontaneous hemopneumothorax 5)
  • as a rare pulmonary manifestation of rheumatoid arthritis 6)

Mechanism of Injury

  1. Blunt chest trauma is far more common than penetrating injury. Blunt trauma may cause sudden increased intrathoracic pressure with airway rupture.
  2. Penetrating chest trauma can result from stab wounds, gunshot wounds, and foreign body impalement (e.g. glass, metal). Penetrating traumas may primarily injure the lung, producing both a pneumothorax and hemothorax in more than 80% of all penetrating chest wounds. Primary mediastinal injury due to penetrating injury may be immediately life-threatening.

Pneumothorax causes

The causes related to the production of pneumothorax are multiple and due to this fact, they have received different denominations such as iatrogenic, traumatic, barotrauma, and spontaneous (primary and secondary) 7). Traumatic pneumothorax is produced due to a direct or indirect injury in the chest 8); however, in some series, traumatic pneumothorax is classified depending on the cause, including iatrogenic pneumothorax and barotrauma in this classification, calling it simply penetrating and nonpenetrating pneumothorax 9). Some of the most common causes of traumatic pneumothorax are traffic accidents, gunshot wounds, rib fractures with pulmonary perforation, and stab wounds 10). Iatrogenic pneumothorax is produced by an injury of the pleura during the course of a medical procedure, either intentionally or unintentionally 11).

Spontaneous hemopneumothorax

Spontaneous hemopneumothorax is a rare condition that is observed in 3%–7% cases of spontaneous pneumothorax where the tear of an adhesion can lead to bleeding with associated hemothorax 12). Spontaneous hemopneumothorax involves accumulation of air and blood within the pleural space in the absence of trauma or other obvious causes 13). Spontaneous hemopneumothorax has been defined as the accumulation of at least 400 mL of blood in the pleural cavity in association with spontaneous pneumothorax 14). The clinical picture can be dramatic due to the hypovolemic shock 15).

Spontaneous hemopneumothorax is attributed to the tearing of a vessel in an spontaneous pneumothorax 16) and pleural fluid hematocrit measurement is needed to distinguish it from blood stained effusions. Spontaneous hemopneumothorax is also rarely reported in patients with SLE (systemic lupus erythematosus), sarcoidosis, cavitary lung metastasis, congenital cystic adenomatoid malformation, hemophilia and bleeding diathesis 17). Spontaneous hemothorax has been rarely reported postpercutaneous transluminal coronary angioplasty (PTCA) 18) as well as in patients with pleural malignancy 19). Malignant pleural mesothelioma usually presents with nonspecific chest symptoms, due to the presence of extensive intrathoracic disease for many months before diagnosis and is rarely asymptomatic 20) with occult disease diagnosed on decorticated pleural biopsies in spontaneous pneumothorax 21).

Hemopneumothorax pathophysiology

The mechanisms of bleeding described in spontaneous hemopneumothorax are bleeding either of a torn apical vascular adhesion between the parietal and visceral pleura 22) or of torn congenital aberrant vessels between the parietal pleura and the bulla 23) as the lung collapses or due to rupture of vascularized bullae 24). Aberrant vessels between the parietal pleura and bullae have also been reported 25). Only a few angiographic studies were done during bleeding showing aberrant vessels of different origin 26). Pathology studies 27) revealed abnormalities around the bulla, or a bulla thickened with collagenous tissue compatible with a torn adhesion. Examination of the aberrant vessel showed fibrosis with alcian blue positivedeposits in the media and in the intima that indicated aninability of the vessel to retract after disruption 28).

Hemopneumothorax treatment

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 29):

  • 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 complications 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.

Emergency department care

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

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.

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.

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

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 30). In comparison with thoracostomy, VATS is associated with fewer postoperative complications and shorter hospital stays.

Thoracotomy

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 31).

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.

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.

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.

Management of Retained Clot

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 32). However, VATS may be successful even in patients presenting late after injury 33).

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 Fibrinolysis

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 34). Some centers prefer the use of tissue plasminogen activator (TPA) 35).

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% 36). 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.

Hemopneumothorax complications

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.

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