Wiler, Jennifer L. MD, MBA
A 20-year-old man presents right after being assaulted. The medics report that he was stabbed once on the left side of his chest, and was responsive at the scene. On arrival in the emergency department trauma bay, the patient becomes unresponsive. As you set up to intubate, what else are you preparing to do to treat the patient?
Chest trauma is the third most common anatomic site of injury in the United States after head and extremity trauma, and it is one of the leading causes of death in all age groups. (Injury 2006;37:1.) Nearly 70 percent of traumatic chest injuries are caused by motor vehicle crashes. (Surg Clin N Am 1989;69:15.) Penetrating thoracic trauma (most commonly gunshot and stab wounds) is less common than blunt trauma but is more deadly, and accounts for approximately 10 percent of all major trauma in the United States. (J Trauma 1990;30:1356.) Penetrating trauma to the chest can result in devastating outcomes from injury to the chest wall, esophagus, aorta, thoracic great vessels, lungs, tracheobronchial tree, heart, diaphragm, spinal cord, vertebra, and the thoracic duct. Rarely, penetrating chest trauma can cause major vascular injuries (approximately 4%).
Thoracotomy, an incision into the chest wall and pleural space, was first reported in 1874. (Injury 2006;37:1.) A procedure commonly done by thoracic surgeons to gain access to the organs of the chest, it is done in rare circumstances by emergency physicians as a last-ditch attempt to gain access to a life-threatening wound resulting from penetrating trauma in patients on the verge of or just after cardiac arrest. (J Natl Med Assoc 2010;102:126.) The goals of ED thoracotomy are to release cardiac tamponade, to perform direct cardiac massage, to control hemorrhage, and to expose the descending thoracic aorta for cross-clamping to optimize circulation to the most vital organs.
The decision to perform ED thoracotomy should consider signs of life, comorbid injuries, mechanism, and facility resources. Signs of life include spontaneous movement or respirations, measurable blood pressure, cardiac electrical activity, and pulse. According to guidelines published by the American College of Surgeons Committee on Trauma, ED thoracotomy is best performed in patients with penetrating chest injuries and signs of life. (J Am Coll Surg 2001;193:303.) Patients with blunt trauma who lose vital signs in the ED or who have massive intra-abdominal vascular injury and hemorrhage are also rare candidates for ED thoracotomy, but they have a very low chance of survival.
For patients who are candidates for an ED thoracotomy, standard resuscitation protocols should be initiated, including blood products for suspected traumatic hemorrhage. Often large amounts of blood products are required for these patients, and that should be a consideration when initiating resuscitation efforts that may be futile.
Emergency physicians who do choose to attempt this procedure should take care to prevent self-injury because bony rib fragments, exposure to multiple sharp instruments, and multiple assistants working in a deep and confined space increase the risk of inadvertent provider injury. Personal protective equipment including mask, gown, and gloves should be worn at all times when performing this procedure to limit communicable disease transmission.
Ideally the airway should be secured prior to incision. Intubation of the right mainstem is ideal to allow for deflation of the left lung, but it is not required to proceed. The patient should be placed in the supine position, with the left arm extended over the head using tape, restraints, or an assistant. The left breast should be lifted caudad in female patients prior to incision. The area of the left and right chest should be cleaned with iodine, and sterile towels or drapes placed to expose the left lateral chest.
Multiple approaches exist for an elective thoracotomy, but the standard ED thoracotomy approach is anterolateral. A large skin incision is made from the left fourth intercostal space (nipple line in men, inframammary line in women) just above the rib to prevent injury to the intravascular nerve bundle at the sternum to the posterior axillary line using a 10 or 20 scalpel blade. Separate the skin, subcutaneous fat, and anterior chest wall muscles (pectoralis, serratus). Then make a small incision through the intercostal muscles. Temporarily stopping ventilation can help decrease the risk of iatrogenic injury.
Place one side of blunt-end scissors through the hole and cut through the entire length of intercostal muscles while protecting the underlying tissue with your nondominant hand. Then place rib spreaders through the incised ribs with the handle at the far posterolateral position in case extension into the right chest wall is necessary. In the injured chest, blood and clots may be visualized, and should be evacuated with suction. Accessing the thorax should take no more than a minute or two.
If injury to the heart is suspected, the pericardial sac should be opened to identify injury and to remove any blood clots causing tamponade. Blood in the pericardial sac may not be obvious on visual inspection. Opening the pericardial sac is required to rule out posterior tamponade. Lift the pericardial sac with tissue forceps and cut the pericardium open with scissors anterior to the phrenic nerve (looks like a horizontal white band) to prevent injury to the nerve or underlying myocardium. Cut the sac open so the heart can be inspected for injury. Lacerations of the myocardium can be repaired with large (2.0) nonabsorbable sutures, tamponade a hole with an inflated Foley catheter balloon, or use temporary digital placement to tamponade a smaller hole. Internal cardiac massage can be performed to perfuse the organs.
The descending thoracic aorta should be cross-clamped to preserve blood flow to the brain and heart (via the coronary arteries), and if needed, control hemorrhage in the abdomen. The left lung should be retracted caudad to expose the descending aorta. The esophagus and aorta can be difficult to differentiate in the hypotensive patient, but geographically the aorta is anterior to the vertebral body, and the esophagus is medial and anterior to the aorta. A nasogastric or orogastric tube can be placed in the stomach to identify the esophagus, but should not delay the procedure.
Once identified, the aorta can then be cross-clamped. Organs distal to the clamped aorta will become ischemic so clamping more than 30 minutes is not recommended. If the patient survives an ED thoracotomy, he will require immediate stabilization in the operating room by a surgeon. If the patient survives to leave the operating room, chest thoracostomy tubes are often placed to drain post-operative fluids and remove trapped air. (Am J Surg 1966;112:686; Am Surg 2002;68:313; Arch Emerg Med 1986;3:95.)
Patients with a single isolated stab wound to the chest with signs of life on arrival have the highest chance of survival of an ED thoracotomy — approximately 17 percent. (J Am Coll Surg 2000;190:288.) Post-ED thoracotomy survival is lower in blunt than penetrating trauma because of associated blunt traumatic injuries such as cardiac contusion and aortic rupture. (J Trauma 1991;31:1076; discussion 1081.) Some believe that ED thoracotomy for blunt trauma is futile (World J Surg 2011;35:34), with survival rates approximately one percent. (J Am Coll Surg 2000;190:288.) ED thoracotomy survival is higher in stab wound victims than gunshot wound victims because of the damage from projectile missile pattern injuries. (J Am Coll Surg 2000;190:288.)
For patients who survive an ED thoracotomy, many post-procedure complications are expected. Post-operative pain is nearly universal, and can lead to atelectasis and pneumonia. Other complications include pneumothorax, hemothorax, tension pneumothorax, subcutaneous emphysema, pleural effusion, infection, bleeding, and respiratory failure. The procedure may also result in iatrogenic damage to any of the thoracic organs including the coronary arteries, phrenic nerve, cardiac conduction system, cardiac valves, and internal mammary artery. Sadly, as many as 50 percent of patients who do survive an ED thoracotomy have anoxic brain injury requiring long-term institutional care. (J Trauma 1990;30:362.)
This patient had an ED thoracotomy performed, which revealed a single laceration of the left ventricle. The laceration was manually occluded by the trauma surgeon's finger while he was taken immediately to the operating room, where the laceration was repaired by the trauma surgery team. The patient survived without significant neurological injury, and was discharged from the hospital. (Photograph depicts emergency thoracotomy in a different patient who did not survive to discharge.)
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Dr. Wiler is an assistant professor of emergency medicine and the medical director of reimbursement at the University of Colorado Denver School of Medicine and an adjunct assistant professor of emergency medicine at the Washington University School of Medicine in St. Louis.
Zofran and Risk of Abnormal Rhythms
The Food & Drug Administration has issued a safety review and labeling change for the anti-nausea drug, Zofran (ondansetron, ondansetron hydrochloride, and generics).
Ondansetron may increase the risk of developing prolongation of the QT interval of the electrocardiogram, which can lead to an abnormal and potentially fatal heart rhythm, including Torsade de Pointes, an uncommon and distinctive form of polymorphic ventricular tachycardia.
The labels are being revised to include a warning for patients to avoid using the drug if they have congenital long QT syndrome because they are at particular risk for Torsade de Pointes. The labels also include recommendations for ECG monitoring in patients with electrolyte abnormalities, congestive heart failure, bradyarrhythmias, or in patients taking other medications that can lead to QT prolongation.
Health care professionals and patients are encouraged to report adverse events or side effects to the FDA's MedWatch Safety Information and Adverse Event Reporting Program, www.fda.gov/MedWatch/report.htm.
© 2011 Lippincott Williams & Wilkins, Inc.