>> Recognize the “deadly dozen” thoracic injuries.
>> Understand the importance of the mechanism and location of injury.
>> Be able to identify the key features of a good assessment of chest injury.
Mechanisms of injury: The method or force that causes a victim’s injuries.
Tension pneumothorax: Positive-pressure air or gas accumulation within the pleural cavity, compressing the lungs and limiting the ability of the heart to function.
Thoracotomy: An incision into the chest cavity.
Pericardial tamponade: Compression of the heart due to increased pressure within the pericardial sac due to accumulated fluid or blood.
Case Study 1
You’re dispatched to a scene in which a young male has been stabbed. On arrival, you hear him screaming in pain and find him diaphoretic and dyspneic. He tells you he was stabbed with a pocket knife. The wound is in the right chest, slightly lateral and just above the nipple. He has distended neck veins, decreased breath sounds on the right chest, a systolic blood pressure of 60 and a heart rate of 130. You provide supplemental oxygen, and then you would do which of the following?
a. Perform drug-facilitated intubation;
b. Place an IV;
c. Perform a needle decompression of the right chest; or
d. Place a chest seal over the wound.
Of course, we know you selected “c” because there are few things more gratifying in trauma care than saving a life with a needle decompression for a tension pneumothorax! You recognized that the patient was maintaining his own airway and the shock was due to inadequate venous return from the elevated pressure in his right chest. Just like other life-threatening problems after injury, putting more volume in a closed space will soon lead to disastrous consequences (e.g., tension pneumothorax, cardiac tamponade, brain hemorrhage and brain edema).
Case Study 2
Shortly after completing your paperwork from the stab wound patient, you’re summoned to care for an intoxicated middle-aged man who drove his car off the road, rolled over a few times and smashed into a tree. He was unrestrained. He’s complaining of severe left chest pain, and you observe abrasions, crepitus and poor chest rise with inspiration of the left chest. His BP is 120/80, HR is 110 and oxygen saturation (SpO2) is 85%. Which of the following would be your next step?
a. Place an IV;
b. Place the patient on high-flow oxygen;
c. Perform a needle decompression of the left chest; or
d. Perform rapid sequence intubation.
When we answer this question, our thought process goes something like this: The airway is intact, and circulation appears reasonable. However, there’s a problem with breathing, so the answer is “b.” The patient likely has a flail chest and may very well have a hemothorax and/or pneumothorax on that side, but vital signs are reasonable so needle decompression is not indicated. This patient will be best served by supplemental oxygen, followed by placing an IV line (“b” is before “c”) while rapidly transporting your patient to the trauma center for definitive care.
These cases are examples of two patients with life threatening thoracic trauma who have different mechanisms of injury. The patient in the first case required a rapid assessment and a decision, as well as a maneuver in the field that saved his life. The second patient required BLS intervention only.
About 25% of trauma deaths in the U.S. result from major thoracic injury. Although most thoracic trauma is ultimately managed without an operation (up to 85%), proper prehospital management is vital in achieving a good outcome. Early recognition of severe or potentially severe thoracic injuries followed by rapid treatment in the field may make the difference between life and death for these patients. Several prehospital interventions are currently available—and some on the horizon—that providers may employ with the potential to reduce the mortality and morbidity of chest injury.
To properly treat these patients, providers should be able to recognize the “deadly dozen” thoracic injuries, understand the importance of the mechanism and location of injury and identify the key features of a good assessment of chest injury. In addition, current monitoring and therapeutic options, and new monitoring technologies are also important in the prehospital management of thoracic trauma.
The ‘Deadly Dozen’
With such vital structures as the heart, lungs and major vascular structures residing in the thoracic cavity, it isn’t surprising that chest injuries can be or become fatal immediately or within hours. The foundation of good trauma care, as taught in Advanced Trauma Life Support and Prehospital Trauma Life Support, is to identify and treat life-threatening injuries in the “golden hour.”
Other than provision of a definitive airway and/or needle decompression of a tension pneumothorax in the field, the vast majority of patients with thoracic injury will be best served by “load and go” with high-flow oxygen and placement of an IV line.
Mechanism of Injury
It’s important to consider that the thoracic cavity not only contains the heart and lungs but also the origination of major vascular structures (e.g., the aorta, subclavian and carotid arteries). Also, running through the mediastinum along with the heart are the major aerodigestive structures, the esophagus, trachea and bronchi. The bottom half of the rib cage protects such major structures of the upper abdomen as the liver, spleen, stomach and kidneys.
In fact, the diaphragm may rise as high as the fourth intercostal space, so penetrating injury in this thoracoabdominal area can injure vital organs both above and below the diaphragm. The thoracoabdominal region is defined as nipples to costal margins in the front and inferior border of scapula to costal margins in the back. The location of penetrating injury is critical to provision of proper prehospital care and hospital evaluation.
It’s important to separate stab wounds from gunshot wounds. In addition, gunshot wounds should be categorized by type, velocity, number of wounds and trajectory. For a categorization of gunshot wounds, go to jems.com/deadly-dozen.
Stab wounds should be characterized when possible by number, location, and the width and length of the blade. It’s critical to identify and accurately describe the anatomic location of stab wounds. It’s not only important to guide the work-up once the patient arrives at the trauma center, but it may determine what you do in the field if a patient suddenly deteriorates.
For example, a patient who becomes pulseless in your ambulance with a single stab wound to “the box” (a rectangle outlined by the clavicles, nipple line and costal margins) will be treated differently from a patient with a chest stab wound lateral to the box. In the latter case, our working diagnosis would be a tension pneumothorax, which will be treated with a needle decompression. The first patient who has a stab wound in the box is likely dying of pericardial tamponade from a cardiac injury. This patient will be best served by “load and go” and communication of this scenario to the trauma center so they may prepare for direct operating room (OR) transport and sternotomy.
Table 2 (article tables) describes important anatomic descriptors for penetrating trauma that may assist in facilitating diagnosis and treatment.
An important aspect of penetrating thoracic trauma is that it has the highest survivability after resuscitative thoracotomy. Patients with a single penetrating injury to the chest are more likely to survive a resuscitative thoracotomy than any other type of patient. Survivability in this scenario has been reported to be 15–35%. No other type of injury comes anywhere close to this survivability (e.g., multiple penetrating injuries or blunt injury at 1–2%). Given this, most trauma surgeons will perform a resuscitative thoracotomy on a patient with penetrating chest trauma that had signs of life in the field and up to 15 minutes of CPR. Therefore, effective CPR and communication with the trauma center would be what’s best in this scenario.
In many ways, blunt injury is more challenging to care for than penetrating injury, because it’s generally less obvious which organs are injured, and it’s often accompanied by more tissue injury and inflammatory response. This is especially true in civilian trauma. Other than an open pneumothorax and cardiac tamponade, the remainder of the “deadly dozen” are more common after blunt injury than penetrating injury.
Blunt injury should be described by mechanism so the trauma team can identify key injuries as quickly as possible. See Table 3 (article tables) for these mechanisms and the potential deadly injuries associated with them.
A good history and physical examination is essential. PHTLS recommends a SAMPLE history (symptoms, age and allergies, medications, past history, last meal and the events surrounding the injury). The physical examination, challenging in the field, should include observation, auscultation, palpation and percussion accompanied by pulse oximetry. A great deal can be learned by taking a minute to perform an adequate thoracic exam with special attention to the findings described in Table 4 (article tables).
A good assessment may be challenging in the field. For instance, the classic signs of a tension pneumothorax may be difficult to identify at a chaotic scene. Cyanosis may be difficult to identify in low-light conditions, especially with blood and dirt present. Distended neck veins is a classic sign but a late finding and won’t be present in a patient who has had substantial blood loss.
Determining whether breath sounds are diminished on one side may be difficult in a noisy environment. Practicing listening to breath sounds as much as possible will help providers to become more proficient. Percussion of the chest to detect hyperresonance may be challenging enough in a quiet environment and nearly impossible at a noisy scene. Tracheal deviation due to a tension pneumothorax is more pronounced in the chest and is usually identified by a chest radiograph, a tool obviously not available in the field. Tracheal deviation in the neck is rarely apparent and is truly a very late sign.
Although prehospital monitoring is becoming more sophisticated all the time, EMS providers shouldn’t lose sight of the basics, which include observation, palpation, auscultation and percussion. All providers should become adept at these techniques and practice them as much as possible.
The utility of these new monitoring options in the prehospital environment is still under investigation. The focused abdominal ultrasound for trauma (FAST) is now an accepted and routine part of the secondary survey during hospital evaluation.
Many reports on the role of ultrasound in the prehospital setting note it can be useful in detecting pneumothoraces, hemothoraces, pericardial tamponade, pulmonary embolism, abdominal hemorrhage and cardiac arrest, as well as being helpful in cases of difficult IV access. It has been demonstrated that paramedics can become adept at using this technology relatively quickly. Considering this and the portability and relatively low cost of ultrasound, we anticipate it becoming more commonplace in prehospital trauma care. Currently, it’s far more commonly employed in Europe than in the U.S.
Another technology, near-infrared spectrometry (NIRS), is being used more commonly in trauma and emergency medicine care to detect tissue oxygen saturation. The currently available monitor, InSpectra StO2 from Hutchinson Technology, measures the oxygen saturation in the thenar eminence, which is the fleshy part of palm below the thumb. The InSpectra StO2 measures oxygen saturation in the capillary beds of these hand muscles giving the provider an estimate of overall tissue perfusion. Initial studies in trauma patients demonstrate that levels less than 75% correlate with other measures of hemorrhagic shock, such as acidosis and the development of organ failure. This device is now available as a portable unit about the size of a small shoe.
Telemedicine is becoming more commonplace worldwide. The ability to transport real-time data and images from the patient’s bedside to a command center manned by physicians and nurses has been available for about 10 years. It’s only a matter of time until this technology will be made routinely available to prehospital providers. EMS providers can transmit not only patient data, such as vital signs, ECG and pulse oximetry, and also images that will be instantly made available to the medical control center. It stands to reason that the ability to share this vital information in real time with medical command will enhance care and decision making.
Although these new technologies may not drastically change care in the field, they may dramatically help the patient by ramping up the response at the hospital. For instance, if medical command is viewing ultrasound images of a pericardium full of blood in a penetrating trauma patient with a NIRS tissue perfusion of 50% and a systolic pressure of 90, it’s likely that patient will be directly transported to the OR for sternotomy, rather than spending precious time in the trauma bay only to have the tamponade worsen.
Although monitoring options have expanded in recent years, our therapeutic options have, for the most part, stayed “tried and true.” These therapeutic options serve a single purpose: to correct problems identified in the primary and secondary survey. Some of the therapeutic options that may be employed in the prehospital care of patients with thoracic injury include:
>> A suction or oral airway device;
>> Nasal oxygen;
>> Bag-valve mask ventilation;
>> Endotracheal intubation;
>> A cricothyrotomy;
>> Needle decompression of the chest;
>> Positive-end expiratory pressure (PEEP);
>> Direct pressure of the hemorrhage;
>> Placement of an IV;
>> Splinting the chest wall;
>> A lidocaine patch over a rib fracture for prolonged transport; and
>> A three-sided occulsive dressing for “sucking” wounds.
Case Study 3
A young man shot in the left lateral chest has an open “sucking” chest wound. He appears to be in shock with some respiratory distress with a BP of 100/60, HR 120, 90% oxygen saturation (SpO2) and diminished breath sounds on the left. It’s a long transport time, so you receive medical direction to perform drug-facilitated intubation. Intubation is successful, and you then place a three-sided occlusive dressing over the “sucking” wound and establish an IV. You place a bag-valve mask with 5 cm PEEP, which improves SpO2. However, he loses his pulse while being loaded into the ambulance. What would you do next?
a. Bolus a liter of fluid;
b. Increase the frequency of bagging;
c. Remove the occlusive dressing; or
d. Perform a pericardiocentesis.
The correct answer is “c.” Importantly, one must always remember that PEEP, either via a continuous positive airway pressure mask or via an endotracheal tube, can worsen any kind of pneumothorax, converting it to a tension pneumothorax. Although the positive pressure may be helping the patient’s oxygenation, it may cause more air to enter the pleural space. Also, if a three-sided occlusive dressing is used on an open pneumothorax and the patient deteriorates, remove the dressing. In this scenario, it would be equivalent to a needle decompression.
Although most thoracic trauma may be treated non-operatively, major thoracic trauma accounts for 25% of trauma deaths. Except for provision of a definitive airway and/or relief of a tension pneumothorax with a needle decompression, the vast majority of thoracic trauma is best served with “load and go,” high-flow oxygen, placement of an IV line and administration of crystalloid solutions as the clinical scenario would indicate.
Understanding the mechanism of injury is helpful in establishing both prehospital and in-hospital management priorities. Patients who sustain a single penetrating wound to the chest have the best survivability after a resuscitative thoracotomy.
Practicing chest assessment skills is vital to being a good prehospital provider. Ultrasound, NIRS tissue oxygenation and telemedicine will likely become more commonly employed as prehospital monitoring options. PEEP, or “over bagging,” may exacerbate a simple or open pneumothorax, converting it to a tension pneumothorax.
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