TSRA Content:
Author: Oğulcan Yılmaz, MD
The spectrum of traumatic injuries to the thorax and how each is treated is beyond the scope of this primer; thus, an emphasis will be placed on the early decision-making algorithm.
All patients are initially treated utilizing ATLS protocols. Imaging obtained during the initial evaluation may include a chest x-ray and CT scan. The most common intervention is a tube thoracostomy. Common parameters used as triggers for operative exploration include the immediate return of 1000-1500 ml of blood with tube placement, drainage of more than 200 ml of blood per hour for two to four hours, or the continuous need for blood transfusion1, regardless of the mechanism of injury. Each situation must be assessed individually with a lower threshold being appropriate under certain circumstances.
The presence of any pericardial effusion on a FAST exam or TTE in a patient sustaining penetrating trauma to the chest or upper abdomen is generally another indication for operative intervention, as it suggests cardiac injury. If the patient has a moderate to large effusion with no hemodynamic changes/symptoms, chronic pericardial effusion may be suspected, especially if there is a likely etiology. Pericardiocentesis or pericardial window may be needed to temporize if the patient is hypotensive. An emergent thoracotomy may be needed if the patient is in extremis. Recall that emergent thoracotomy involves opening the pericardium, temporary repair or control of exsanguinating cardiac injury, internal cardiac massage and/or defibrillation, hilar clamping for major pulmonary hemorrhage or airway disruption, and possibly cross-clamping the aorta. The incision employed to access the chest is guided by suspicion of the location of the injury.
Common approaches include:
1. Thoracotomy
Thoracotomy is the most commonly utilized surgical approach in trauma. It provides adequate exposure to the lung, pulmonary hilum, and diaphragm on the side of the thoracotomy. A left thoracotomy also exposes the distal intrathoracic esophagus, descending thoracic aorta, and distal left subclavian artery, while a right thoracotomy exposes the proximal intrathoracic esophagus, intrathoracic trachea, right subclavian artery, SVC, and azygos vein. The pericardium can be opened to relieve tamponade from a thoracotomy on either side. The proximal left subclavian artery is probably best accessed via a left supraclavicular incision (isolated injury) or at sternotomy (if additional mediastinal injuries are anticipated). A thoracotomy in the emergent situation is generally anterior and can be extended across the sternum to create a bilateral thoracosternotomy or "clamshell" incision, which provides access to both thoracic cavities and the mediastinum.
2. Sternotomy
Sternotomy provides excellent access to the heart as well as the ascending aorta, aortic arch, innominate artery/vein, SVC, and left carotid artery. The trachea may be accessed through a sternotomy; however, injuries to the cervical and intrathoracic trachea are probably best approached through a neck incision and right posterolateral thoracotomy, respectively. A left supraclavicular extension of the midline incision creating a "trap door" can improve access to the proximal left subclavian artery when necessary. A fair amount of certainty that the injuries are limited to the above-mentioned structures is recommended before the sternotomy because it is difficult to convert to another approach following this incision.
3. Thoracoabdominal Incision
In cases where the descending thoracic aorta is injured in a manner that approaches or spans the diaphragm, it is necessary to have access to both the pleural and peritoneal cavities to obtain proximal and distal control for repair. A left thoracotomy in one of the lower intercostal spaces can be extended in an oblique manner anteriorly and inferiorly to permit access to both cavities.
When preparing to go to the operating room for chest trauma, in addition to the standard adjuncts (blood products, fluid warmer, rapid transfusion setups), it may be necessary to have available an endoscope (for suspected esophageal injury), flexible bronchoscopy (for suspected tracheal/bronchial injuries), and/or intraoperative TEE (for cardiac injury).
4. Tube Thoracostomy (Chest Tube Insertion)
For bedside insertion of chest tubes, the usual location is tunneled over the superior aspect of the rib in the 5th intercostal space, anterior to the mid-axillary line. The temptation to enter a space inferior to this should be resisted as it is possible (especially anteriorly) to enter the peritoneal cavity inadvertently. The pleural cavity extends as far down as the 7th intercostal space anteriorly, 9th intercostal space laterally, and 11th intercostal space posteriorly. The general steps of inserting a chest tube should be familiar to most; however, pitfalls still exist.
Unless a specific area of loculated fluid is being targeted, direct the tube posteriorly and towards the apex, a location that optimizes drainage of both fluid and air; this may be facilitated by pointing the Kelly clamp with its tip curving away from the hemithorax as you direct the tube posteriorly and towards the apex. Some practitioners instead use a trocar to help direct chest tubes; be aware of the sharp tip on some such trocars if this technique is used. Ensure that the chest tube is not bent by confirming that it will easily rotate in place. Prevent extrathoracic placement of the tube by inserting a finger into the pleural cavity and confirming placement before insertion, as well as visualizing fogging of the tube and/or respiratory variation in the tube after insertion. The size of the tube and manner of insertion may vary depending upon the indication for the procedure.
Pneumothoraces can normally be evacuated effectively with either a pig-tail catheter (8-10 Fr) placed percutaneously, or a small-bore (20-24 Fr) chest tube inserted either percutaneously or in the conventional fashion. The latter may be reserved for ongoing processes that are likely to leak a great deal of air. While it is the traditional bias of many surgeons to place a chest tube, percutaneously inserted catheters that are less painful to insert and maintain deserve consideration when treating a pneumothorax.
If placing a tube percutaneously on the left side, examine the CXR for cardiomegaly and be mindful of the heart to avoid a fatal complication. Pleural effusions range widely in complexity and consistency. If the patient is stable, it is prudent to obtain a CT scan of the chest to assess the characteristics of an effusion; if the effusion is especially loculated/complex, the patient may be better served with a decortication in the operating room, as bedside chest tube placement may be inadequate or difficult.
If a bedside thoracostomy is to be performed, the size of the chest tube chosen should reflect the anticipated quality of the fluid to be drained: smaller tubes (24-28 Fr) are adequate for draining a serous simple effusion; larger tubes should generally be used in the setting of an empyema (28-32 Fr) or hemothorax (32 Fr or larger). If a persistent effusion exists and pleurodesis either fails or is contraindicated, an indwelling drainage catheter (PleurX™ catheter) can be placed, which the patient can manage as an outpatient. Conventional thoracentesis may be an option when the fluid is free-flowing and the effusion is either initial or slowly recurrent. Ultrasound-guided thoracentesis may be useful for sampling or draining a localized collection of fluid.
Chest Tube Management
The management of chest tubes can be fairly individualized to the practitioner, although several general guidelines exist. In most situations, water seal is preferable to suction as it decreases the duration of air leaks. However, if the air leak is brisk enough to overwhelm the water seal and cause significant subcutaneous emphysema or a pneumothorax much larger than anticipated based on the amount of lung resected, placing the chest tube on suction is indicated.
Empyema, pleurodesis, and decortication are other situations in which suction is commonly used in the initial postoperative period. To confirm tube patency, ensure that there is no mechanical obstruction of the tubing and examine the fluid inside the tube and/or the fluid inside the water seal chamber for respiratory variation. Air leaks may be grossly quantified as small, moderate, or large, and if large, can be further classified as expiratory or continuous.
To assess for an air leak, first, have the patient cough. The patient can be asked to either perform the Valsalva maneuver or continuously enunciate a letter to attempt to differentiate between a large space and a leak. The former will be characterized by the disappearance of bubbling through the Pleur-evac®; the latter will not. If the exam is equivocal or if the patient has failed prior chest tube removal due to recurrent pneumothorax, it can be helpful to clamp the chest tube and obtain a CXR 4 to 6 hours (and up to 24 hours) later to determine if an air leak is present, with the caveat that both the patient and nurse should be cognizant to the possibility of developing acute respiratory distress and the need to immediately unclamp the tube should this occur.
If the patient has an unexplained air leak, confirm that the tube has not become disconnected and that there is not a gap in the skin around the tube through which air is being entrained. The tube may be removed when the air leak resolves and the amount and consistency of fluid being drained reaches an acceptable level ("acceptable" varies by surgeon and situation - however, for non-empyema situations, <150-200 ml/day is a reasonable, if somewhat conservative, threshold).
An "empyema tube" is slowly backed out over several days to weeks to avoid re-accumulation of infected fluid, even if the amount draining is low. If the patient needs to be discharged with a chest tube in place, a Heimlich valve can be attached. This is a one-way valve that can be attached to a sputum trap or drainage bag, with the caveat that if an air leak exists, there must be a vent in the drainage container from which air can escape. To see if an air leak still exists with a Heimlich valve present, have the patient cough while observing the valve mechanism for fluttering; alternatively, immerse the exit opening of the valve in a cup of water and observe for bubbling when the patient coughs.
Hemoptysis
Hemoptysis can range from mild, blood-tinged sputum to life-threatening intrapulmonary hemorrhage. The first consideration in the setting of large-volume hemoptysis is to secure the airway. Initial management of hemoptysis includes monitorization of vital parameters such as SpO2, improvement of oxygenation, positioning of the patient with the suspected bleeding side down to prevent flow down the unaffected lung, sedation, and anxiolysis.2 If the hemoptysis is massive, a large-diameter endotracheal tube should be inserted as quickly as possible to maintain gas exchange.
Endotracheal suctioning and evacuation of blood from the bronchial tree with concomitant ventilation may be performed until flexible or rigid bronchoscopy equipment becomes available.
Although the bleeding may subside temporarily, it is imperative to attempt to localize it to direct future therapy should the bleeding recur. Flexible or rigid bronchoscopy should be done to locate the origin of the bleeding and to clear the airway of any clots and blood. If active bleeding is noted, additional temporizing maneuvers, such as cold saline lavage, main-stem intubation of the unaffected side, or placement of a bronchial blocker down the affected side, can be employed.
If the patient is stable, a CT scan of the chest provides invaluable information regarding the potential source of massive hemoptysis. Bronchial artery embolization (BAE) is usually the next step in the algorithm, as surgery carries a high morbidity rate in the emergent situation and risks failure if the lesion has not been properly localized.
Pulmonary angiography and embolization of possible offenders may be considered if a bleeding vessel is not seen on BAE and the patient continues to bleed. Finally, if surgical therapy is pursued because of failure of other interventions, the goal is generally lobectomy with the removal of the source of bleeding as suggested by the above-mentioned studies.
Added References:
1. Surgeons ACo. Advanced Trauma Life Support: Student Course Manual. . Chicago, IL2018.
2. Ittrich H, Bockhorn M, Klose H, Simon M. The Diagnosis and Treatment of Hemoptysis. Dtsch Arztebl Int. 2017;114(21):371-81.