Sandbox: Sima NourAli

Overview

[Haemothorax refers to a collection of blood within the pleural cavity. By definition this bloody pleural effusion should contain a haematocrit value of at least 50% of the haematocrit of peripheral blood.PMID:20817498]

Pathophysiology

[Pathogenesis Bleeding into the pleural space can occur with virtually any disruption of the tissues of the chest wall and pleura or the intrathoracic structures. Blood that enters the pleural cavity is exposed to the motion of the diaphragm, 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. However, when this lysis is incomplete or bleeding is relatively large, clot formation is inevitably. Once the clot has been allowed to organize, it will adhere to the lung and pleura, making it difficult to remove. The agitation of cardiac and respiratory movement rapidly defibrinates the blood, and a fibrin clot thus formed is deposited on the visceral and parietal pleura, setting the stage for a trapped lung. In its early development, this thin membrane has little substance and is attached very loosely to the underlying pleural surface. By the seventh day, there is an angioblastic and fibroblastic proliferation. The membrane continues to thicken by progressive deposition and organization of the coagulum within the cavity. An understanding of the pathologic features of a clotted haemothorax makes it clear that, if possible, the clotted haemothorax should be evacuated within a reasonable time after onset of bleeding.PMID:20817498]

Causes

[Iatrogenous haemothoraces are known to occur as a complication of cardiopulmonary surgery, placement of subclavian- or jugular-catheters or lung- and pleural-biopsies/sclerotherapy of oesophageal varices, rupture of pulmonary arteries after placement of Schwann–Ganz catheters, thoracic sympathectomy and translumbar aortography./Spontaneous haemothoraces are generally caused by rupture of pleural adhesions (3–7% of all cases), neoplasma (schwanommas, soft tissue tumours, and hepatocellular carcinoma), pleural metastasis, and as a complication of anticoagulant therapy for pulmonary embolism.3 Less frequent causes reported in the literature are rupture of aneurysmatic thoracic arteries such as the aorta, mammarian arteries and intercostal arteries (e.g. Ehlers Danlos syndrome, and neurofibromatosis), rupture of pulmonary vascular malformations (Rendu-Osler-Weber syndrome), endometriosis, and exostoses.PMID:20817498] [Most cases of hemothorax are related to blunt trauma, procedures, neoplasm such as schwanommas of von-Recklinghausen disease and soft-tissue tumors, and vascular ruptures. Spontaneous pneumothorax is also a caused of spontaneous hemothorax. Hemothorax may result in respiratory distress, respiratory failure, retained clot, fibrothorax, empyema and extended hospitalization.PMID:26197910] [The primary cause of haemothorax is sharp or blunt trauma to the chest. Iatrogenous and spontaneous haemothoraces occur less frequently.PMID:20817498]

Treatment

[Initial treatment Chest tube drainage In most cases, chest tube drainage by means of a large calibre (≥28 French) tube is an adequate initial approach unless an aortic dissection or rupture is suspected.2, 3 After the tube thoracostomy is performed, a chest radiograph should always be repeated in order to identify the position of the chest tube, to reveal other intrathoracic pathology and to confirm whether the collection of blood within the pleural cavity has been fully drained. Surgical approach in the acute phase

The criteria for surgical exploration, as detailed in the literature, are blood loss by chest tube 1.500 ml in 24 h or 200 ml per hour during several successive hours and the need for repeated blood transfusions to maintain haemodynamic stability.4, 5, 6

Patients with active blood loss but with stable haemodynamics can be treated with Video-Assisted Thoracoscopic Surgery (VATS), not only to stop the bleeding but also to evacuate blood clots and breakdown adhesions. A series of 50 VATS procedures, performed in patients with traumatic haemothorax, demonstrated active blood loss in eleven subjects.4

Thoracotomy is the procedure of choice for patients with haemodynamic instability due to active bleeding.2 Surgical exploration allows control of the source of bleeding and evacuation of the intrathoracic blood. Prophylactic antibiotics

Antibiotic treatment following haemothorax reduces the rate of infectious complications.7, 8, 9, 10 The Eastern Association for Trauma developed guidelines based on nine prospective placebo-controlled studies, including several double blinded studies and two meta analyses. Most of the cases enrolled in these studies were penetrating chest traumas, but some studies also included patients with spontaneous haemothorax. The guidelines recommend the use of first generation cephalosporins during the first 24 h in patients treated with chest tube drainage for haemothorax. In the included studies however, a broad range of antibiotics was applied. When empyema occurs during chest tube drainage, antibiotic treatment should be directed to Staphylococcus aureus and Streptococcus species.8

In a comment on this guideline, results of different studies were combined to generate incidence rates. The authors concluded that prophylactic use of antibiotics during at least 24 h after the start of chest tube drainage for haemothorax, reduced the incidence of pneumonia from 14.8% to 4.1%.9 The incidence of empyema decreased from 8.7% to 0.8%.

Another randomised controlled study, performed after the publication of these guidelines, also revealed fewer infectious complications in the group of patients treated with prophylactic antibiotics.10

The duration of antibiotic treatment remains a point of discussion and recommendations vary from 24 h to the moment of chest tube removal. In general, 24 h of antibiotic treatment is advised in traumatic haemothorax.8 Whether antibiotic prophylaxis is useful for spontaneous haemothorax has not been investigated accurately. Intrapleural fibrinolytic therapy

Intrapleural fibrinolytic therapy (IPFT) can be applied in an attempt to evacuate residual blood clots and breakdown adhesions when initial tube thoracostomy drainage is inadequate. Retention of blood in the pleural cavity may lead to lung entrapment, chronic fibrothorax, impaired lung function and infection. Several small non-randomised studies report on IPFT with streptokinase (250,000 IU), urokinase (100,000 IU or 250,000 IU) or tissue plasminogen activator (TPA).11, 12, 13, 14, 15, 16 The intervals between the day of onset of haemothorax and the start of treatment varied from 4 to 165 days. Whether IPFT can be initiated prior to the fourth day is not clear from the published reports. Generally, it is advised to evacuate the clotted haemothorax within 7–10 days.4

Reports on duration of treatment with IPFT vary between 2 and 9 days for streptokinase and 2–15 days for urokinase.

In most cases, treatment with IPFT leads to complete resolution of radiographic abnormalities, through evacuation of blood clots and loculated effusions. Less than 10% of cases need a more aggressive treatment by means of surgical decortication.

Bleeding complications due to a possible systemic effect of fibrinolytic substances were not reported in the studies using streptokinase and urokinase. A study using recombinant tissue plasminogen activator as a fibrinolytic agent, was reported on one patient who developed haematuria requiring blood transfusion.16

The relationship between the time frame of IPFT or conversion to surgical intervention and the risk of developing long-term complications has not been established in the published literature.

If chest tube drainage and IPFT does not lead to sufficient resolution of the retained clots, surgical intervention should be considered. Surgical approach in a later phase VATS

Optimal evacuation of residual clots, breakdown of adhesions and loculated effusions is important in order to prevent a complicated course leading to empyema or fibrothorax. A volume of 500 ml of blood or an amount of blood filling one third of a hemithorax is considered an indication for surgery.17, 18, 19, 20

Chest X-ray seems to be an inadequate tool in establishing the indication for VATS. The surgical procedure should therefore be preceded by computer tomography (CT), to be able to detect locations and residual clots with high accuracy.18, 21, 22

The estimated amount of fluid on CT scans has been shown to correlate very well with the true amount of fluid harvested by VATS.22

VATS evacuation of the haemothorax or retained clot can be performed safely. One-lung ventilation is not required. A single lumen tube can be used with directions to anaesthesiologist 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.

A randomised study in patients with incomplete resolution of clots and blood after chest tube drainage reported shorter length of hospital stay and shorter duration of tube drainage in a group of patients treated with VATS as compared to a group treated with additional tube drainage.17

Several prospective and retrospective non-randomised studies in small groups of patients show favourable results of VATS (80%–100%) with high effectiveness and low morbidity.6, 19, 21, 20, 21, 22, 23, 24, 25, 26

However, the methods of evaluation were not reported in all of these studies and IPFT was not integrated in the therapeutic strategy. An optimal period between trauma and VATS of 48–72 h is repeatedly advocated, although a longer interval is more common.6, 19, 21, 26

Longer intervals between the start of haemothorax and VATS lead to increased rates of complications, according to some authors.19, 20 Thoracotomy

Thoracotomy is the procedure of choice for surgical exploration of the chest when massive haemothorax or persistent bleeding is present. At the time of surgical exploration, the source of bleeding can be controlled and a haemothorax evacuated. Thoracotomy is usually required for adequate empyema drainage and/or decortication. In 10% of cases a thoracotomy is necessary to treat the haemothorax.6

A longer time span between the appearance of haemothorax and VATS increases the chance of intraoperative conversion to thoracotomy, prolongs postoperative drainage time and is associated with a higher incidence of hospital admissions.19, 27 When haemothorax is complicated by empyema, the duration of hospital stay also increases.PMID:20817498]

Surgery

[In haemodynamically unstable patients inspection and drainage of the pleural cavity by thoracotomy is indicated, whereas in haemodynamically stable patients VATS is considered the treatment of choice.PMID:20817498] [The management of hemothorax has been a complex problem since it was 1st described over 200 years ago.PMID:26197910] [Traditionally, lrage hemothorax is treated primarily by closed thoracic drainage by inserting a large-caliber chest tube in stable patients/In hemodynamically unstable patients with more than 1,000 ml of blood drainage from the initial thoracotomy or ongoing blood losses of more than 100 to 200 ml/h, an early surgical approach with ongoing resuscitation is needed./Video-assisted thoracoscopic surgery （VATS）, minimally invasive surgery, grows and finds new applications for the patients with hemothorax as both diagnostic and therapeutic interventions/VATS is an accurate, safe, and reliable operative therapy in the 5-day post event window, but there is a decreasing success rate after this time period.PMID:26197910] [*chest tube drainage

• Video-assisted thoracoscopy PMID:9262119]