A 25-year-old male drives into an unseen wire while he is snowmobiling. The wire strikes his anterior neck and throws him from his snowmobile. Paramedics are unsuccessful in placing an endotracheal tube (ETT) in the field. He arrives in the emergency department (ED) immobilized on a long spine board and with a cervical collar in place. He is unconscious, unresponsive to painful stimuli, and stridorous. Initial vital signs include a heart rate of 120 beats per minute, a blood pressure of 160/90 mm Hg, a respiratory rate of 24 breaths per minute, and an oxygen saturation of 93% on room air. A non-rebreather oxygen mask is applied, and his oxygen saturation increases to 97%.

Palpation demonstrates no obvious subcutaneous air, but there is a large abrasion across the anterior and lateral areas of the neck (Figure 21–1). Palpation of the larynx demonstrates crepitus and slight anatomic distortion. Plans begin immediately to further protect and secure the airway.

What Are the Important Considerations in Evaluating This Patient?

Upon arrival at the ED, the team should follow a protocol that is consistent with the guidelines of the Subcommittee of Advanced Trauma Life Support^® of the American College of Surgeons Committee on Trauma.^1–3 Aggressive initial management and a high index of suspicion for associated injuries are key steps in the successful management of patients with this type of injury.

A young patient with no significant medical history should have adequate cardiorespiratory reserve. His initial oxygen saturation is concerning, which prompts the addition of supplemental oxygen. His depressed level of consciousness could be due to a number of factors; anoxic injury to the brain or spinal cord must be a consideration. His blood pressure, elevated pulse rate, and use of accessory muscles of respiration would suggest that his cervical cord is essentially intact. Despite two small studies which suggest that laryngotracheal injury is compatible with a normal cervical spine,^4,5 the airway practitioner must assume that this patient has a cervical spine fracture until proven otherwise.^2,6

Other associated injuries can occur with this type of “clothesline injury.” These include facial lacerations, vascular injuries, laceration of the esophagus,⁷ and injury to the recurrent laryngeal nerve.⁸ It is imperative to thoroughly evaluate the patient after first ensuring airway, breathing, and circulation.

What Are the Airway Priorities in This Patient?

The urgency of the presentation places the airway practitioner in a difficult situation. Unfortunately, a comprehensive evaluation of the airway will not be feasible. It is possible to anticipate where difficulties will arise, however, and rapid anatomic and physiologic evaluation of the patient is essential.

Anatomic considerations in this patient include the potential for laryngeal fracture, tracheal disruption, and an expanding hematoma which could impinge on the airway; all of these may be difficult to detect and could compromise airway patency.^9,10 Blunt anterior neck trauma can also negatively influence all four components of initial airway management in this patient: bag-mask-ventilation (BMV), use of the extraglottic devices (EGDs), laryngoscopy and intubation, and cricothyrotomy.

The anatomic concerns could lead to physiologic dysfunction; oxygenation and ventilation could both present problems. Difficulty with BMV could stem from either anatomical upper airway distortion due to the trauma itself, tracheal disruption, or to trauma related to prior intubation attempts. Additionally, the use of EGDs may be contraindicated in the setting of supraglottic or glottic disruption or distortion.^11–13

The airway practitioner should anticipate difficult laryngoscopy. Supraglottic or glottic distortion may hinder visualization of the vocal cords. In the event the practitioner elects to pursue direct laryngoscopy, a Miller blade may be the preferable blade, as it may provide better control of the epiglottis and a more direct line-of-sight vision.¹⁴ Video-laryngoscopy can provide superior views of the glottis^15,16 and may be preferable unless airway bleed which cannot be controlled or suctioned obscures the camera view.

However, it must be understood that a clear view of the cords does not guarantee successful endotracheal intubation in this case. One must recognize that blunt anterior airway trauma may result in disruption or transection of the trachea distal to the glottis.² Tracheal transection may result in obstruction to tube passage or placement of the tube in a false passage through the tracheal disruption. Orotracheal laryngoscopy cannot detect this injury and may lead to a false sense of security relative to the “ease” of intubation.¹⁷ One case series demonstrated six of seven tracheal disruptions to be at the cricothyroid/tracheal junction; four of these seven were successfully intubated while the others required emergency tracheotomy.¹⁷

Cricothyrotomy may be very difficult in laryngeal trauma, as normal anatomic landmarks may be distorted, making it difficult to identify the larynx, the cricothyroid membrane, and the cricoid ring. In addition, subcutaneous air may compromise the capacity to identify the trachea to perform percutaneous needle puncture and for this reason, an open surgical technique is the preferred surgical approach (see Chapter 14 for details).

What Should We Consider in Managing This Patient’s Airway?

This airway is not a “crash airway,” but it is a difficult one and needs to be secured urgently. Difficulty should be expected with BMV and laryngoscopy; the airway is possibly disrupted and neck mobility is limited. Difficulty can also be anticipated with EGD utilization and with cricothyrotomy (potential for hematoma and laryngeal/tracheal distortion).

Summoning help is the first step in the management of this patient. There is some time to formulate a plan. The use of paralyzing agents or drugs which might lead to respiratory depression should be avoided in this patient. Conversely, coughing could worsen the injury, or could further compromise a traumatized spinal cord. Careful sedation and topical anesthesia are appropriate in this patient, and in-line stabilization of the cervical spine is an absolute requirement.

Typically, orotracheal intubation should be performed by the most experienced laryngoscopist immediately available.^18,19 In addition, in-line stabilization of the cervical spine should be employed to protect against exacerbating an unstable cervical injury. Further, in a patient who has a potentially disrupted distal airway, the procedure of choice is intubation using a flexible bronchoscope (FB).^19–21 This technique permits visualization as one advances into the trachea and ensures that the ETT is not advanced into a blind passage. Traditional intubation with orotracheal, direct- or video-laryngoscopy can result in disruption of false passages or creation of pseudo-lumens which could compromise the patient’s airway. Even the gentle placement of an Eschmann Introducer (EI) (“gum-elastic bougie”) may create an airway obstruction in these patients,^1,2,19,22 although case reports exist of successful “bougie”-guided tracheal intubation in patients with tracheal injury penetrating neck wounds.²³ Confirmation of correct placement with an FB is important. A failed airway mandates an attempt at cricothyrotomy.^18,19

Step by Step, What Is the Best Way to Intubate the Trachea of This Patient?

Timing is key. If time permits, the FB equipment should be prepared. Additionally, laryngoscopy and cricothyrotomy/tracheotomy equipment should be opened at the bedside and the patient’s neck should be prepped and anesthetized. A BMV device, suction, and airway adjuncts (such as oral and nasal airway devices) should be prepared. The primary plan would be to perform an awake flexible bronchoscopic intubation assisted by procedural sedation and topical anesthesia.^2,19 In a pediatric patient, oral intubation with a smaller sized ETT might be preferable.² If forced to act, the plan must change to an attempt at an oral direct- or video-laryngoscopy assisted with a bougie or a primary cricothyrotomy dependent on the airway practitioner’s experience and capabilities.^2,18,19

Denitrogenation with a non-rebreather mask is essential. A well-oxygenated patient gives the airway practitioner a cushion of time in the event tracheal intubation is difficult and requires more time.²⁴ Steadily declining oxygen saturations may mandate assisted ventilation by a bag-mask. It is important to reiterate that EGDs are contraindicated in this patient as they may actually worsen the existing airway distortion. In the presence of oxygen desaturation and the airway practitioner is unable to oxygenate with a bag-mask, an immediate surgical airway is indicated.¹⁸

Waiting for nebulized or atomized 4% lidocaine to provide topical anesthesia might be counter-productive, as these agents typically require 15 minutes to take effect.^25,26 Anti-sialogogues might be considered if time permits, although should not delay attempts at sedation and laryngo-bronchoscopy.

Numerous sedating agents may be considered, including ketamine, propofol, midazolam, or etomidate. Ketamine (with or without propofol) is a good choice for this patient as it carries the benefit of analgesia, along with sedation, before the rare complication of associated laryngospasm, or emergence reaction.^27,28 Propofol and midazolam may have the advantage of practitioner’s familiarity and ease of titration, although both drugs can potentially precipitate complete obstruction through a loss of muscle tone.^29,30 Dexmedetomidine might be a consideration if extra help is available to titrate the drip to effect.^31,32 The advantage of etomidate is its relative cardiovascular stability. However, the potential myoclonus associated with etomidate³³ may place the potential unstable cervical spine and patency of a possible tenuous airway at risk.

Neuromuscular blocking agents should be avoided.^2,18 The amount of time the practitioner has to perform bronchoscopy and intubation will depend on the ability to maintain oxygen saturation. High-flow nasal oxygen during the bronchoscopic attempt might assist to provide prolonged maintenance of oxygenation.³⁴ A change of plan is indicated if glottic structures cannot be seen during the awake-look.

Oxygen desaturation, failure in ventilation, or failure to visualize the airway after several viewing attempts (no more than three) indicate a failed airway.¹⁸ In this circumstance, cricothyrotomy is in order.^2,19 Open cricothryotomy is preferable to percutaneous techniques for the reasons stated above, including the creation of a false passage. This method allows the practitioner to identify the trachea and intubate under direct visualization. Blind attempts at finding the distal airway are rarely successful.^3,35