Preparation
All emergency and surgical personnel at a Role 2 or higher facility should be trained in their roles and actions to facilitate performance of an ERT.
All needed supplies and equipment for an ERT should be pre-packaged and stored in a readily accessible location in the resuscitation area, and periodically inspected for completeness and service ability.23
The surgeon and designated team members should review the contents and composition of the ERT supply package.
All personnel performing, assisting, or otherwise participating in an ERT should be wearing full personal protective equipment including a gown, gloves, and eye protection.
The urgency of the procedure, coupled with the mix of multiple assistants and multiple potential sharps represent a high-risk scenario for accidental injuries and infectious disease exposure to the involved medical personnel (See JTS Infection Prevention in Combat-Related Injuries CPG.24 Great care must be taken during training and actual ERT procedures to highlight safety precautions including control of all needles, syringes, scalpels, and other sharps.
Sterile preparation is not required for ERT, as the nature of this procedure does not afford the time for prep solutions to dry and assume their antimicrobial efficacy.
If at all possible, definitive airway control should be obtained prior to or during ERT, but ERT should not be delayed solely to establish a secure airway.
Efforts to obtain adequate intravenous or intraosseous access for blood product infusion should proceed simultaneous to ERT, keeping in mind that in the case of penetrating thoracic trauma, infusions via the upper extremities may be ineffective until bleeding is controlled. Similarly, lower extremity, pelvic, or abdominal wounds with exsanguination should be resuscitated via an upper extremity or central venous catheter. In the patient with difficult intravenous access, intraosseous access should be immediately established, preferably in the sternum or humerus.
Placement of a right chest tube if there is any possibility of injury/hemorrhage on the right side should be strongly considered. Alternatively, the right chest may be open through an extended thoracotomy or clamshell incision.
Effective suction should be available for successful ERT.
Incision and Exposition
- ERT begins with a generous curvilinear left anterolateral thoracotomy (from the sternum to the table) at approximately the fourth intercostal space. If previously performed, a tube thoracostomy incision can serve as a starting point for the thoracotomy. Exposure can be significantly improved by placing a towel or roll under the left back to elevate and rotate the left chest.
- The nipple line in males and the inframammary crease in females is a reasonable anatomic landmark (time should not be spent attempting to count ribs). If in doubt, it is best to err more superiorly rather than make too low an incision.
- After the initial incision with a knife to/through the level of the chest wall muscles, heavy scissors may be used to rapidly and safely open the remaining tissues through the full extent of the incision by sliding the partially opened scissors along the superior rib border.
- The internal mammary vascular pedicle is located 1-2cm lateral to the sternal border and will be transected during ERT. Transection of these vessels is of no physiologic consequence, but control of associated bleeding (only after return of circulation in case of successful procedure) with suture or clips will be necessary.
- If after initial left ERT, additional right-sided thoracic, cardiac or pulmonary hilar exposure is needed, the incision should rapidly be extended across the sternum (with a Lebsche knife or simple trauma shears) and continued on the right side (bilateral thoraco-sternotomy or “clamshell” incision).
- Once the incision is completed, a rib retractor is placed (with the handle downward), the ribs are spread and the lung is initially packed posteriorly with laparotomy pads or sterile towels, or manually retracted by an assistant; this can be facilitated by incision of the inferior pulmonary ligament. After evacuating blood and/or formed clot from the left pleural space, the pericardium is visualized to assess for cardiac activity and for hemopericardium.
NOTE: One of the most common technical errors in ERT is poor exposure due to inadequate length of the skin incision and lack of complete division of the subcutaneous and muscle layers.
Cardiac Procedures
- Pericardotomy: The pericardium is opened longitudinally at least one finger breadth anterior to the phrenic nerve which can be identified in its cranio-caudal course along the lateral pericardium, generally within 1-2cm of the pulmonary hilum. The pericardium should be opened by grasping with a forceps and using a tissue scissor, followed by extension down to the diaphragm and cephalad to below the thoracic inlet. In cases with a large hemopericardium, tension may make grasping the pericardium with forceps difficult. The heart can then be delivered partially out of the pericardium to inspect for injury and facilitate open cardiac massage if needed.
- If after pericardiotomy, a cardiac injury is identified, initial temporary control may be achievable with digital pressure, a large side-biting clamp, a Foley catheter, or even a surgical skin stapler.
- In the absence of effective cardiac activity, open cardiac massage should be rapidly instituted at this point using a two-handed technique, which is less traumatic and produces a better cardiac output. This will be ineffective unless concurrent volume resuscitation has occurred sufficient to provide adequate preload.
- Defibrillation must be early attempted in cardiac arrest. If internal paddles are available, an electric shock is typically delivered at 20 Joules. If not, external paddles can also be used in the usual cutaneous position at 200 J, after temporarily removing the costal retractor so as to briefly close the chest cavity.
- If there is no cardiac injury and no cardiac activity (asystole), resuscitative efforts should be terminated after a reasonable time (5-10 minutes).
- In case of successful restoration of cardiac activity, cardiac or other intrathoracic injuries should be more definitively repaired, and exploration completed.
Aortic Cross-Clamping
- If there is known or suspected hemorrhage from below the diaphragm, initial attention after thoracotomy should be focused on clamping the descending thoracic aorta. The lung is retracted and packed anteriorly and superiorly to identify the aorta in its location just anterior to the vertebrae. This can be facilitated by incising the inferior pulmonary ligament.
- The aorta should be clamped just above the diaphragm to maximize collateral flow and spinal cord perfusion. In exsanguinated or asystolic patients (i.e., with a “flat” aorta”), the esophagus is easily mistaken for the aorta. Placing an orogastric or nasogastric tube will help identify and avoid injury to the adjacent esophagus (located just medial/anterior to the aorta).
- Opening the mediastinal pleura, limited blunt dissection is used on either side of the aorta to facilitate the placement of a large, atraumatic DeBakey vascular clamp.
- After the clamp is placed, aggressive resuscitation may be instituted and immediate plans made for direct surgical control of the patient’s injuries. If a patient remains severely hypotensive despite fluid resuscitation after aortic clamping, it is unlikely that he has a survivable injury.
- The duration of intra-thoracic aortic cross clamp should be carefully monitored, and the maximum tolerated duration in the patient already in hemorrhagic shock is 30-40 minutes. It should be removed at the earliest possible time, or the level of cross clamp could be moved inferiorly to the abdominal aorta or iliac vessels if proximal control of abdominal, pelvic, or extremity vascular injuries is still required. Once the injury is addressed, as the clamp is removed, the team should be prepared for rapid hemodynamic shifts and the potential development of hyperkalemia and/or metabolic acidosis (ischaemia-reperfusion injury or “reperfusion syndrome.”).
Injury Within The Thorax
If after thoracotomy, there is a direct injury to the lung or hilar vessels, direct pressure (with a finger, rolled gauze, or laparotomy sponge) is generally sufficient for temporary control of bleeding in this low pressure system. Using lap pads to collapse the lung parenchyma medially will pack the hilum and free up your hands initially to allow a more detail inspection of the chest, heart, and vessels for sites of hemorrhage, and allow the placement of the aortic clamp. Some major pulmonary injuries might need early hilar cross-clamping en masse.
Once temporary control is in place, resuscitation can be instituted and the patient may be taken to the operating theatre for definitive lung repair with stapled resection, suture repair, stapled “tractotomy,” or in extreme cases pneumonectomy (which carries a very high mortality in the trauma setting, even in the absence of pre-procedural arrest).
Large pulmonary injuries also create a risk for air embolism which can result in entrained air entering the pulmonary veins and subsequently the left heart and coronary vessels. Early pulmonary hilar clamping, rapid direct control of lung lacerations or temporarily submerging the area in irrigation fluid can help prevent this risk.
If there is a thoracic great vessel injury, temporary control may be achievable with digital pressure or atraumatic vascular clamps. If these are insufficient to control a great vessel injury in the setting of an ERT, this likely represents a non-survivable injury.
Unlike pulmonary bleeding, intercostal and chest wall bleeding is under arterial pressure and will require more focal and firm pressure for initial control, followed by mass suture ligatures and/or clip.