STABILIZATION OF THE PATIENT
One of the most difficult problems in emergency medicine is the patient presenting with serious head or facial trauma, an altered mental status, and respiratory arrest or respiratory insufficiency requiring immediate airway intervention. In these patients, because of the abnormality of mental status (which may include frank coma), it is not possible before radiologic evaluation for the physician to exclude a potentially unstable injury to the cervical spine. For this reason, the neck must remain immobilized until such time when an injury is radiologically excluded. Immobilization is provided by a combination of a spine board (to which the patient’s head and body should be secured), a rigid or semirigid cervical collar (not a soft collar), and an assistant who remains at the head of the bed and maintains the head in the neutral position; all movement of the neck is thereby prevented, and other diagnostic and therapeutic maneuvers may safely be undertaken.
After immobilization, patients who are unconscious without respiratory effort require intubation to establish a functional airway, and this must be a first priority. Laryngoscopically guided oral intubation is the technique of choice and must be undertaken without movement of the cervical spine; an assistant is essential in this regard and should remain at the patient’s head providing constant, in-line stabilization. Patients with inspiratory effort may be nasotracheally intubated provided that significant maxillofacial, perinasal, or basilar skull injuries are not present; when present or suspected, nasotracheal intubation is relatively contraindicated.
In patients
with inspiratory effort but without adequate ventilation, mechanical obstruction of the upper airway should be suspected and must be quickly reversed. The pharynx and upper airway must be immediately examined and any foreign material removed either manually or by suction. Such material may include blood, other secretions, dental fragments, and foreign body or gastric contents, and a rigid suction device or forceps is most effective for its removal. Obstruction of the airway related to massive swelling, hematoma, or gross distortion of the anatomy should be noted as well, because a surgical procedure may then be required to establish an airway. In addition, airway obstruction related to posterior movement of the tongue is extremely common in lethargic or obtunded patients and is again easily reversible. In this setting, insertion of an oral or a nasopharyngeal airway, simple manual chin elevation, or the so-called jaw thrust, singly or in combination, may result in complete opening of the airway and may obviate the need for more aggressive means of upper airway management. Chin elevation and jaw thrust simply involve the manual upward or anterior displacement of the mandible in such a way that airway patency is enhanced. Not uncommonly, insertion of the oral airway or laryngeal mask airway may cause vomiting or gagging in semialert patients; when noted, the oral airway should be
removed and chin elevation, the jaw thrust, or the placement of a nasopharyngeal airway undertaken. If unsuccessful, patients with inadequate oxygenation require rapid sequence oral, or nasotracheal, intubation immediately.
If an airway has not been obtained by one of these techniques, Ambu-bag-assisted ventilation using 100% oxygen should proceed while cricothyrotomy, by needle or incision, is undertaken rapidly. In children younger than 12 years, surgical cricothyrotomy is relatively contraindicated and needle cricothyrotomy (using a 14-gauge needle placed through the cricothyroid membrane), followed by positive pressure insufflation, is indicated. During the procedure, or should the procedure be unsuccessful, Ambu-bag-assisted ventilation with 100% oxygen and an oral or a nasal airway may provide adequate oxygenation.
In addition, rapidly correctable medical disorders that may cause central nervous system and respiratory depression must be immediately considered in all patients and may, in fact, have precipitated the injury by interfering with consciousness. In all patients with abnormalities of mental status, but particularly in those with ventilatory insufficiency requiring emergent intervention, blood should immediately be obtained for glucose and toxic screening, and the physician should then prophylactically treat hypoglycemia with 50 mL of 50% D/W, opiate overdose with naloxone (0.4-2.0 mg), and Wernicke encephalopathy with thiamine (100 mg). All medications should be administered sequentially and rapidly by intravenous injection and any improvement in mental status or respiratory function carefully noted. Should sufficient improvement occur, other more aggressive means of airway management might be unnecessary.
After an airway is established and secured, a rapid focused examination of the patient should be performed. First, the adequacy of ventilation must be determined by careful assessment of the chest and specific interventions undertaken as indicated; replacement of intravascular volume and control of blood loss remain additional priorities.
Patients without shock but with persisting abnormalities of mental status unresponsive to the administration of dextrose, naloxone, and thiamine must be assumed to have significant head injuries, and treatment should be initiated as described in “Head Injury.” Importantly, however, in patients with a serious head injury and established or evolving shock, the customary means of reducing intracranial pressure (restriction of fluids, the administration of furosemide, mannitol) must be abandoned and the more immediately life-threatening deficit in intravascular volume corrected aggressively. In any patient presenting with trauma, but particularly in the patient with an abnormal mental status, the possibility of occult chest or abdominal injuries (or both) must be carefully investigated and excluded. When injuries to these areas are noted and pose an immediate threat to life, the neck must remain immobilized while appropriate intervention is pursued.
CERVICAL SPINE INJURY
Approximately 5% to 10% of unconscious patients presenting as a result of a fall or motor vehicle accident have a major injury to the cervical spine. A number of findings may further suggest cervical spine injury; these include other associated injuries above the clavicle, diaphragmatic breathing or apnea, flaccid areflexia including a flaccid rectal sphincter, a sensory level as demonstrated by facial gesturing in response to painful stimuli above the clavicles but not below them, and hypotension associated with a normal heart rate and warm extremities (spinal shock). Priapism, although unusual, is further suggestive of spinal injury.
As discussed in “Stabilization of the Patient,” absolute immobilization of the cervical spine using a combination of a spine board, to which the patient’s head is secured, and a rigid cervical collar is required until such time when the entirety of the cervical spine is demonstrated to be normal radiologically. To this end, a lateral radiograph of the cervical spine must be rapidly obtained; downward traction on the patient’s arms will facilitate visualization of the more distal vertebrae and should be undertaken initially.
Unfortunately, on the initial lateral view of the cervical spine, only the first five or six cervical vertebral bodies are typically identified. This must not be interpreted by the physician as a normal study. In fact, an initial view of the cervical spine in the injured patient that demonstrates only the more proximal vertebrae can be an important diagnostic clue to the presence of a distal (C6 or C7) cervical injury. The pathophysiologic mechanism explaining this is that injuries to the distal cervical cord leave the shoulder elevators unopposed; involuntary elevation of the shoulders in these patients thereby obscures radiographic demonstration of the more distal cervical vertebrae. Thus, the only acceptable initial study of the cervical spine is a lateral view in which all cervical vertebrae, including C7 and the C7-T1 interface, are well visualized. To this end, the x-ray technician frequently requires the assistance of the emergency department staff. Most often, if gentle but firm downward traction on the arms is applied, a satisfactory view may be obtained. If a second view is unacceptable, the swimmer’s view should be obtained and will demonstrate the most distal vertebrae. When the initial portable lateral view is normal, an anteroposterior, lateral, and open-mouth odontoid view of the cervical spine should be obtained in stable patients; if this is normal, immobilization of the neck may be discontinued and further evaluation of the patient’s injuries undertaken. When immediate surgical intervention for other injuries is not required and the above views of the spine are complete and normal, further radiologic assessment of the skull may proceed. The open-mouth odontoid view will significantly decrease the number of patients in whom the diagnosis of an important cervical injury is missed, and this should routinely be obtained before allowing unrestricted movement of the patient.
If any doubt exists after these initial studies as to the possibility of a significant cervical injury, or if a potentially unstable or significant cervical injury is demonstrated, immediate neurosurgical or orthopaedic consultation should be obtained. Computed tomography (CT) is another imaging modality that can be used; often, in the head-and neck-injured patient, it is time-saving to scan rapidly through the head and neck. Recent studies have demonstrated there may be benefits of methylprednisolone in patients with acute spinal cord injuries; when this diagnosis is highly probable based on physical examination, patients presenting within 8 hours of injury may benefit from an initial intravenous bolus of 30 mg/kg, followed by 5.4 mg/kg/h for 24 hours. Patients treated in this manner may demonstrate improved neurologic status subsequent to the injury; patients presenting after 8 hours should be discussed with a neurosurgical or orthopaedic specialist. During this time, the patient should remain immobilized on a spine board to which the head has been secured utilizing a rigid or semirigid cervical collar (not a soft collar).
Serious injuries to the
neck in children represent a difficult challenge for the emergency physician. Most cord injuries in children occur as a result of motor vehicle accidents or falls and are often associated with injuries to the head. The type of injury one expects is somewhat related to the age of the child.
In children younger than 7 to 8 years, because of larger head-to-body ratio (relatively), there is increased ligamentous laxity and lack of vertebral ossification, and injuries to the upper cervical spine are most common. These are often subluxation injuries rather than actual fractures.
This often produces the
SCIWORA phenomenon, or spinal cord injury without radiographic abnormality. The most common cause is a fall or motor vehicle accident; injury occurs as a result of transient impingement of unstable vertebral elements against the cord, which when spontaneously reduced appears radiologically normal. Some patients will report weakness, paresthesias, or pain in the neck or back; however, in some children, neurologic abnormalities may not be noted for several days. This diagnosis is important to consider in patients with symptoms suggesting possible spinal cord injury (paresthesias, transient weakness or referred pain, electric or shocklike symptoms in the neck or back, persisting pain), commonly associated injuries or findings (head injury, loss of consciousness, mental status abnormalities), or significant mechanisms of injury (falls, diving, deceleration or rotational injuries associated with motor vehicle accidents [MVAs]). Undiagnosed spinal cord injury associated with instability may result in additional injury to the cord.
Children older than 8 years typically injure the lower cervical spine, and most injuries are visible by x-ray; there is significantly less concern regarding SCIWORA.
Patients in whom a spinal cord injury is suspected, based on history, examination, or radiologic findings, should remain strictly immobilized while emergent neurosurgical or orthopaedic assistance is obtained; particular attention should be directed to the patient’s airway and overall respiratory status. Cervical injuries at or above the third cervical vertebra cause immediate loss of spontaneous respiration, whereas injuries somewhat below this level may also jeopardize adequate ventilation. The current recommendation regarding the establishment of an airway in patients requiring airway intervention after traumatic arrest is cautious orotracheal intubation with in-line immobilization; patients who are unconscious, but breathing, and who require airway intervention are best managed with cautious rapid-sequence orotracheal intubation. Both nasotracheal intubation and cricothyrotomy cause less movement of the cervical spine; however, both are technically more difficult and potentially more timeconsuming, particularly cricothyrotomy.
In regard to management, all patients with neck symptoms, even if minimal, should remain immobilized and have plain cervical spine films performed; all seven cervical vertebrae should be visualized, including the C7-T1 interface. Because of the unreliability of negative plain films in younger children, all patients require a careful reevaluation in regard to developing symptoms and signs of spinal cord injury. Children with signs of neck injury, persisting or progressive symptoms, or specific symptoms suggestive of spinal cord injury (see previous) should have additional studies, including CT-enhanced or -directed imaging in selected or suspicious areas. MRI, if rapidly available, can also be useful in these cases in terms of directly assessing cord and ligamentous injuries, provided the patient is sufficiently stable. Additionally, in patients with a mechanism of injury associated with spinal cord injury, particularly in younger children, additional studies should be considered. Older children who remain completely asymptomatic and who have normal physical findings and a mechanism of injury unassociated with spinal cord injury can generally be discharged after a brief period of observation without ancillary studies. Any developing findings require CT tomography or MRI before discharge. Any positive or suspicious findings should be discussed with the orthopaedist or neurosurgeon.