NECK TRAUMA

神經外科齊龍駒

Background: Few emergencies pose as great a challenge as neck trauma.

Because a multitude of organ systems (eg, airway, vascular, neurological, gastrointestinal).

Airway occlusion by hemorrhage is the most immediate risks to life.

Awareness of the various presentations is critical for improving patient outcome.

Anatomic relationships

Structures at risk:the spine posteriorly, the head superiorly, and the chest inferiorly, the anterior and lateral regions are most exposed to injury. The larynx and trachea The spinal cord lies posteriorly, cushioned by the vertebral bodies, muscles, and ligaments. The esophagus and the major blood vessels are between the airway and spine.

Anatomic zones

The majority of the important organs lie within the anterior triangle bounded by the sternocleidomastoid posteriorly, the midline anteriorly, and the mandible superiorly.

Zone I is the thoracic inlet to the cricoid cartilage level.

Structures at greatest risk in this zone are the great vessels (subclavian vessels, brachiocephalic veins, common carotid arteries, and jugular veins), aortic arch, trachea, esophagus, lung apices, cervical spine, spinal cord, and cervical nerve roots.

Zone II the midportion of the neck and the region from the cricoid cartilage to the angle of the mandible.

Important structures in this region include the carotid and vertebral arteries, jugular veins, pharynx, larynx, trachea, esophagus, and cervical spine and spinal cord.

Zone III : the superior aspect of the neck and is bounded by the angle of the mandible and the base of the skull.

Mechanisms of injury

Penetrating trauma GSWs sustain greater injury than stab wounds.Bullets tend to course randomly and follow a more direct pathway. After a GSW to the neck, surgery is indicated in 75% of cases, while only 50% of neck stab wounds require surgical exploration.

Vascular injuries from penetrating trauma may causing a partial or complete transection of the vessel or formation of intimal flap, arteriovenous fistula, or pseudoaneurysm. Blood vessel injury results from external compression, mural contusion, or thrombosis occurring in 25-40% of patients.

Major nerve injury occurs in 3-8% of patients sustaining penetrating neck trauma.

Spinal cord injury occurs infrequently and almost always results from direct injury rather than secondary osseous instability.

Blunt trauma :

Blunt trauma to the neck typically results from motor vehicle accidents, sports injuries, strangulation, and excessive manipulation (ie, physical realignment or repositioning of the spine).

Nonpenetrating trauma can injure a blood vessel through a multiple mechanisms. Direct forces can shear the vasculature. Excessive rotation and/or hyperextension of the cervical spine causes distention and stretching of the arteries and veins to the point of rupture.Basilar skull fractures may disrupt the intrapetrous portion of the carotid artery.

Impact to the anterior neck may crush the larynx or the trachea, particularly at the cricoid ring, and compress the esophagus.

A sudden increase in intratracheal pressure against a glottis, or a rapid acceleration-deceleration action may cause a tracheal injury.

Strangulation may result from hanging, ligature suffocation, manual choking, and postural asphyxiation.

Significant cervical spine and spinal cord damage happens in a fall from a distance greater than the body height.

Simple asphyxiation is not the major cause of death in hanging injuries.

Frequency: In the US: Neck trauma accounts for 5-10% of all serious traumatic injuries. Mortality/Morbidity: The overall mortality rate has decreased to 2-6%.Initially missed cervical injuries result in a mortality rate of greater than 15%. Ten percent of neck wounds lead to respiratory compromise. Loss of the airway patency may resulting in mortality rates as high as 33%. Zone I injuries are associated with the highest morbidity and mortality rates.

CLINICAL

History: clinical manifestations may vary greatly. The presence or absence of symptoms can be misleading, serving as a poor predictor of underlying damage. For example, only 10% of patients with blunt vascular damage develop symptoms in the first hour.

When trauma results from a motor vehicle accident, inquire about seat belt use, location of the patient in the car, deployment of an air bag, and magnitude of car damage.

In the penetrating trauma, try to verify details about the weapon, such as type and size of knife or type and caliber of gun.

For patients with hanging, try to determine the suspension time, drop height, ligature used, history of alcohol or drug abuse.

Symptoms relating to the aerodigestive tract include dyspnea, hoarseness, dysphonia, and dysphagia.

CNS problems include paresthesias, weakness, plegia, and paresis.

Physical: Airway loss may occur. Determine airway patency, breathing, and adequacy of circulation. Most importantly, a single examination is never sufficient, since the onset of signs of injury may be delayed with neck trauma. The platysma serves as the harbinger for serious penetrating neck wounds. Any violation of the platysmal muscle should alert the physician to the potential damage to the neck.

If the platysma is violatedJudge whether the wound lies anterior (anterior triangle) or posterior (posterior triangle) to the sternocleidomastoid muscle.Determine in what zone the injury is found.Try to specify the direction of the wound tract Half of the penetrating neck trauma in which the platysma is violated have no further injury.If the platysma clearly is not violated, the patient can be safely cleared of a significant underlying injury.

Consider an arterial injury if have a hematoma;

asymmetry of arterial pulses; a new bruit on auscultation; neurological deficits, or hypotension.

Do not probe or manipulate the wound or perform any action that may cause the patient to gag, choke, or cough.

Any of these reactions may dislodge a clot and provoke a life-threatening hemorrhage.

Hard signs of an arterial injury :

A large expanding hematoma,

severe active pulsatile bleeding

shock unresponsive to fluids

signs of cerebral infarction

presence of a bruit or thrill

diminished distal pulses.

Virtually all patients with hard signs of an arterial injury require operative repair.

Perforation of the pharynx or the esophagus following blunt neck trauma rarely occurs.

Initiallymay have no complaints

physical examination fails to reveal injury.

Since the wall of the esophagus is fragile, iatrogenic injury can follow endoscopy, passage of a nasogastric tube, or inadvertent esophageal intubation.

Esophageal perforation is the most serious and rapidly fatal trauma-induced perforation of the gastrointestinal tract.

Signs of cord / brachial plexus injury

Brachial plexus injuries from blunt trauma tend to involve the upper nerve roots (C5 to C7).

Quadriplegia occurring with complete transection of the spinal cord manifests as an absence of all motor, sensory, and reflex function below the level of injury.

Brown-Sequard syndrome

Urinary retention, fecal incontinence, paralytic ileus

Horner syndrome results from disturbances of the stellate ganglion.

Neurogenic shock

Hypoxia and hypoventilation can follow disruption of phrenic innervation.

Signs of larynx or trachea injury

Voice alteration, Hemoptysis, Stridor, Drooling, Sucking, through the neck wound.

Subcutaneous emphysema and/or crepitus Hoarseness, Dyspnea.

Distortion of the normal anatomic appearance.

Pain on palpation or with coughing or swallowing, Crepitus (This hallmark sign of disruption to aerodigestive tract.)

Signs of penetrating injuries of the heart, aorta, and great vessels

Hemorrhage, associated with large wounds

Massive hemothorax

Hypotension

Tamponade

Weak or absent carotid or brachial pulse

Paradoxical pulse

Bruit

Cervical or supraclavicular hematoma

Bleeding from the entrance wound

Upper extremity ischemia

Coma

Hemiparesis

Respiratory distress secondary to tracheal compression

Signs of tracheobronchial or lung injurySubcutaneous emphysema Cough Respiratory distress Hemoptysis Tension pneumothoraxContinuous air leak after chest tube insertion Mediastinal crunch (Hamman crunch) Intercostal retractions Decreased breath sounds Hyperresonance to percussion

Tachypnea

Agitation

Hypotension

Tachycardia

Hypoxia

Shifting of the trachea

Signs of carotid artery injuryDecreased level of consciousness Contralateral hemiparesis Hemorrhage Hematoma Dyspnea secondary to compression of the tracheaThrill Bruit Pulse deficit

Signs of jugular vein injury

Hematoma

External hemorrhage

Hypotension

Signs of cranial nerve injuries

Facial nerve : Drooping of the mouth angle

Glossopharyngeal nerve: Dysphagia

Vagus nerve : Hoarseness (weak voice)

Spinal accessory nerve : Inability to shrug a shoulder and to laterally rotate the chin to the opposite shoulder

Hypoglossal nerve : Deviation of the tongue with protrusion

Signs of esophagus and pharynx injury

Dysphagia

Bloody saliva

Sucking neck wound

Bloody nasogastric aspirate

Pain and tenderness in the neck

Resistance of neck with passive motion

Crepitus

Bleeding from the mouth or nasogastric tube

WORKUP

Imaging Studies: Do not delay transport to the operating roomCervical x-rays3-view series of the cervical spine. Chest x-rayAny finding suggestive a zone I wound or damage to the thoracic cavity : ordering a chest x-ray.review the film for hemothorax,pneumothorax, widened mediastinum, mediastinal emphysema, apical pleural hematoma, and foreign bodies.

Supplementary tests

CT scans, MRIs, color flow Doppler studies, contrast studies of the esophagus, angiograms, and endoscopic images.

TREATMENT Airway

Breathing

Circulation

Disability

Exposure

Miscellaneous

Consultations: Consult an experienced trauma surgeon emergently once platysmal violation is confirmed.

Urgent surgical exploration of a penetrating wound to the neck is indicated for the following: Continued blood loss, expanding hematoma, hypovolemic shock, and/or pulse deficitAirway obstruction, impending airway obstruction, open trachea, and/or air bubbling from the wound siteNeurologic deficitBlood in the aerodigestive tract, hemoptysis, and/or hematemesisNew-onset bruit

Prognosis:Zone I injuries have the worst prognosis.Zone II injuries have the best prognosis. Complete disruption of the spinal cord above C4 is frequently fatal. Vascular injuries arising from blunt trauma are associated with a poor outcome.The prognosis is poor when severe neurological deficits (eg, hemiparesis, coma) occur due to carotid artery damage. Early revascularization may improve the outlook.

Identification of pharyngeal or esophageal injuries as soon as possible because delayed diagnosis leads to significant morbidity.

If the Glasgow score is greater than 3, the chances are good that the patient with a choking or strangulation injury will eventually be discharged neurologically intact.

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