Recognizing and Managing Traumatic Neck Injuries - JEMS

2021-12-30 11:48:40 By : Ms. Kallen Zhang

Injuries to the neck can be both complex and challenging for the prehospital provider. Whether the injury is blunt or penetrating, the provider must maintain a high index of suspicion for underlying injury even if the patient appears to have only minor superficial injuries. As will be discussed further, these patients have the potential for rapid decompensation as these types of injuries carry with them a high probability of morbidity and mortality.

Scenario 1 You’ve just started your Saturday afternoon shift with your local EMS service. The first call comes for a 26-year-old at a baseball field struck in the side of the neck with a baseball bat by a teammate. You’re told en route the patient is having difficulty breathing, and swelling is noted to the left lateral side of his neck. Dispatch informs you he’s still awake and alert.

On arrival, you find your patient sitting upright on the bench, in obvious respiratory distress, with an ice pack applied to his neck. On initial evaluation, you note the patient is having moderate stridor with inhalation and exhalation. You remove the ice pack to find what appears to be a large hematoma on the left side of the anterior neck. The patient is tachycardic to 115 beats per minute, blood pressure (BP) is 138/74, and respirations are 30 per minute and shallow. You wonder if this patient has something more significant and consider your management options.

Scenario 2 Later that night, you’re called to a local bar where a fight has broken out and the patrons thought they observed someone getting stabbed. Once the scene has been secured by police, you find a male in his 20s with an obvious stab wound to his neck.

The patient has mild bleeding from the site and is now starting to spit up blood. No other trauma is noted. Your patient’s pulse is 120 beats per minute, BP is 100/60, respiratory rate is 30 and shallow, and pulse oximetry is 92%. The patient is moved quickly to the awaiting ambulance. As you’re preparing to leave the scene, you wonder if there are more definitive ways of managing this patient’s injury.

Anatomy The anterior neck has a concentration of critical anatomy that includes vascular, respiratory, digestive and neurologic structures. Many of these structures are close to the skin and easily injured.

The anatomy of the neck has classically been divided into two different schemes. The first scheme divides the neck into anterior and posterior triangles. The anterior triangle is bounded by the midline, the lower border of the mandible, and the anterior border of the sternocleidomastoid muscle. The structures contained within the anterior triangle include the carotid artery, internal jugular vein, vagus nerve, thyroid gland, larynx, trachea and esophagus. The posterior triangle is bounded by the middle third of the clavicle, the anterior border of the trapezius muscle and the posterior border of the sternocleidomastoid muscle. Structures contained within the posterior triangle include the subclavian artery and the brachial plexus.

The second way of categorizing the anatomy of the neck is by zones. This is the method used by most hospitals and trauma surgeons to help guide management once the patient has arrived at the hospital.

Zone I is defined as the area from the clavicles to the cricoid cartilage. Structures within this zone include the vertebral and proximal carotid arteries, major thoracic vessels, superior mediastinum, lungs, esophagus, trachea, thoracic duct and spinal cord.

Zone II extends from the inferior margin of the cricoid cartilage to the angle of the mandible. The carotid and vertebral arteries, jugular veins, esophagus, tracheal, larynx and spinal cord are found in this zone.

Zone III is located between the angle of the mandible and the base of the skull. It includes the carotid and vertebral arteries, pharynx and spinal cord.

The neck is also divided into fascial planes. The platysma–a large, thin sheet of muscle extending from the facial muscles to the thorax–is the traditional surgical landmark for penetrating trauma. Any injury to Zone II of the neck that penetrates the platysma typically necessitates the patient go to the operating room for surgical exploration because of the number of vital structures located in this zone.

An object’s mass and shape will determine the extent of a penetrating injury.

Pathophysiology Neck trauma is divided into three categories: penetrating, blunt, and strangulation injury.

Penetrating neck trauma: The pathophysiology of penetrating injury varies greatly by the mechanism of injury. One mechanism with an associated high morbidity and mortality is gunshot wounds, which can be further divided into low- and high-energy injuries. Bullets shot from high-power weapons such as assault rifles transfer a much greater degree of energy than bullets shot from a low-velocity handgun shot from the same range. In addition to energy, other factors determining the type and extent of injury are the mass, shape and fragmentation characteristics of the bullet, and location and thickness of the penetrated tissue. Low-energy bullets such as shotgun pellets follow erratic trajectories along the tissue pathway of least resistance and may result in the pellet moving to the heart or other organs.

Stab wounds are another commonly seen cause of penetrating neck trauma, but may be deceiving based on how the entrance wound appears. It’s often difficult to determine the depth and path of penetration. A high index of suspicion for underlying injury must be maintained even if the wound appears minor on the surface.

Penetrating neck trauma can lead to large vessel injury resulting in hemorrhagic shock. Carotid injuries can also produce a rapidly expanding hematoma that may distort the normal airway anatomy and make endotracheal intubation very challenging. Furthermore, large lacerations of the jugular venous system can lead to an air embolism, causing hypotension and respiratory distress.

Blunt neck trauma: In contrast to penetrating trauma, blunt neck trauma may not be initially detected due to injuries of other anatomical areas including the chest, abdomen and head. Common mechanisms that produce blunt trauma include motor vehicle collisions, where the unrestrained passenger’s neck can decelerate against the dash or steering wheel. Also, the shoulder harness portion of the seatbelt can create a shearing injury to the neck. There may also be blunt trauma from airbag deployment.

Other mechanisms of blunt neck trauma include clothesline-type injuries (from activities such as football or running into a tree) and bicycle handlebar injuries. Laryngeal trauma can be caused by a direct blow to the anterior aspect of the neck that compresses the firmer thyroid and cricoid cartilages against the cervical spine. This can result in a laryngeal fracture, the hallmark of which is inspiratory stridor.

Blunt trauma also has the potential for vascular injuries. Direct blows to the anterior neck can compress and potentially rupture the carotid, causing a rapidly expanding hematoma that has the potential to distort or occlude the airway. There are also rotational injuries caused by a direct blow to the head that can hyperextend the carotid artery across the cervical spine, causing a dissection of the wall of the artery. The carotid artery can also be injured in the setting of blunt oral trauma and basilar skull fracture. Patterns of injury to the carotid include dissection, formation of pseudoanerysm, and thrombosis.

Blunt trauma can also induce neurologic injury. Besides the obvious possibility of cervical spine fracture and cord injury, any injury to the vascular structures of the neck has the potential to impair cerebral blood flow, thus leading to neurological symptoms like paralysis contralateral to the injured carotid. Inline cervical immobilization should be maintained in these patients due to the risk of cervical spine injury.

Prehospital Management The initial management of any neck injury should include the standard methods of evaluating any trauma patient, including a directed primary survey, resuscitation, rapid transport and a secondary survey.

Airway: Both penetrating and blunt neck trauma can compromise the airway. Factors that prompt early, aggressive airway management include acute respiratory distress; airway obstruction from blood, secretions or laryngeal injury; massive subcutaneous emphysema of the neck; tracheal shift; altered mental status; or expanding neck hematoma. Options such as rapid sequence intubation (RSI)/medication-assisted airway management should be considered early if your system allows these procedures.

During the initial exam of the patient, one should recognize the potential for distortion of the normal airway anatomy from injuries such as tracheal laceration, laryngeal fracture and expanding hematomas. The exam should evaluate for change in voice including evidence of stridor. Other signs and symptoms, such as air bubbling from the wound, tracheal deviation or hemoptysis, should elevate the provider’s suspicion for tracheal injury. The physical exam should also include palpation of the neck to evaluate for an expanding hematoma, presence of a pulsatile mass and the presence of subcutaneous emphysema.

Should the patient continue to have respiratory compromise secondary to secretions or blood in the airway, standard suctioning techniques should be employed. Given the amount of trauma, continuous suction may need to be implemented in order to maintain a patent airway. This can be accomplished with a French suction catheter or a Yankauer/rigid tip catheter left in the airway and the suction device set to intermittent suction.

Early airway intervention in these patients is critical. Orotracheal intubation is the airway management of choice, but injury pattern and distortion of anatomy may inhibit standard intubation. Cricothyrotomy may be indicated when factors such as increased risk of tracheal transection or a false intubation passage are present.

There’s also concern with dislodging a contained hematoma within the neck. In some patients, the injury itself may create a tracheostomy site. In these cases, the existing tracheostomy site may be intubated as a lifesaving means of securing the airway. When contemplating RSI on these patients, one must always consider the possibility of not being able to intubate the patient. Therefore, an RSI approach must be done with caution or even avoided, if possible.

Depending on the situation, a supraglottic airway (SGA) may be effective. Of course, if the patient has obstructive laryngeal edema and the patient can’t be intubated, the SGA will not be effective and the only option may be a surgical airway. Because the anatomy is often significantly disrupted in neck injuries, surgical airways can be difficult and complicated.

Breathing: After evaluating and securing the airway, the provider’s attention should be turned to breathing. It should be noted that the apices of the lungs are located in Zone I, and injury to this area–especially from penetrating trauma–may predispose the patient to lung injury including pneumothorax, hemothroax or tension pneumothorax. Needle thoracostomy may be indicated in these patients should respiratory difficulty and/or failure develop.

Circulation: As previously mentioned, blunt or penetrating injuries can lead to significant injury of the large vessels of the neck including the carotid arteries and the jugular venous system. Any source of significant hemorrhage should be controlled with direct pressure at the site of the injury. If there’s concern about injury to the venous system, an occlusive dressing such as Vaseline gauze would be indicated to prevent the possibility of air embolus. Blunt injury to the neck can lead to arterial dissection with the possibility of complete occlusion of the vessel. It’s important to remember that injury to the arteries of the neck can present with neurological signs mimicking a stroke.

In most settings, penetrating neck trauma necessitates transport to the closest trauma center. Blunt trauma, however, may not need a Level 1 trauma center if the patient doesn’t have evidence of other multisystem injury and is stable after a thorough assessment.

A knife impalement injury can compromise the airway and cause difficulty breathing.

Return to Scenario 1 You secure the patient’s cervical spine by maintaining inline stabilization. He’s moved to the stretcher for transport to the closest trauma center. En route, the patient becomes increasingly tachypneic with increasing stridor, and the decision is made to intubate the patient using RSI.

The patient is delivered to the trauma center where he undergoes CT scans of his neck as well as angiography. It’s determined he has a partially ruptured internal carotid artery with evidence of dissection and a large hematoma in the anterior neck. The patient is taken immediately to the operating room by vascular and trauma surgery where he undergoes repair of his carotid artery. The patient is subsequently discharged several days later in stable condition.

Return to Scenario 2 The patient continues to have poor oxygen saturations in the high 80s to low 90s despite administration of supplemental oxygen. During transport, the patient’s mental status starts to change as he becomes less alert. An attempt is made to ventilate the patient with a bag-valve mask and it’s noted there’s bubbling from the wound and new evidence of subcutaneous emphysema. You quickly realize there’s likely injury to the trachea as well as to the vascular structures of the neck. The patient is intubated using RSI. He’s transported to the closest trauma center where it’s discovered he has a partial laceration to the jugular vein as well as a laceration to the trachea. The patient undergoes surgical repair and is discharged from the hospital several days later.

Conclusion Penetrating and blunt neck injuries continue to be a challenge for the prehospital provider. Having a good understanding of the anatomy of the neck, including the location of critical structures, is vital to provide effective prehospital care. Airway management is critical in these patients and if in doubt, earlier definitive airway management should be undertaken. This often requires skill in multiple airway maneuvers including BLS ventilation techniques, intubation and, if need be, surgical approaches.

One must also be aware that injuries to the neck can occur in isolation, but they often coexist with other multisystem trauma. Constant mindfulness of the ABCs and maintaining a high index of suspicion for airway, vascular and neurologic injury will help the prehospital provider deliver optimal care for victims of neck trauma.

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