Airway Management For Neck Trauma Alex Sigalovsky, CRNA As anesthesia providers / airway managers our primary concern in patients with neck injuries is to secure the airway. Distorted anatomy, hemorrhage, edema, foreign bodies and the urgency of the situation at times make this task challenging and often intimidating. The methods of airway management of in these patients remains a controversial topic. There is no consensus. In fact, experts often have very conflicting opinions. The choice will ultimately depend on the patient's situation and the expertise of the airway team. My goal today: 1) Teach you something you don’t already know 2) Provide insight on how we handle these airways at WFST 3) Offer suggestions you may wish to consider incorporating into your practice

Objectives Anatomy Classifications Mechanisms Airway Cases Summary The literature on penetrating and blunt neck trauma in emergency medicine, trauma, anesthesia, radiology, and otolaryngology is enormous, often contradictory, and concentrates more on specific diagnostic modalities and surgical treatment than initial management. The majority of studies are retrospective reviews of various diagnostic modalities, as opposed to initial management

Anatomy of Neck A complex network of muscles, vessels, and nerves – all supported by fascial planes Two primary classifications utilized in description of neck injuries: Zones Triangles The high density of vascular, aerodigestive and neurologic structures within the neck makes the management of injuries difficult, especially penetrating ones, and contributes to the morbidity and mortality seen in these patients. Leonardo da Vinci. Study of a Man with his Head Turned, c. 1495

Anatomy: Neck Contents Musculoskeletal structures: vertebral bodies; cervical muscles, tendons, and ligaments; clavicles; first and second ribs; and hyoid bone. Neural structures: spinal cord, cervical roots of phrenic nerve and brachial plexus, recurrent laryngeal nerve, cranial nerves (specifically IX-XII), and stellate ganglion. Vascular structures: carotids, vertebral arteries, & vertebral vein, brachiocephalic vein, and jugular veins. Visceral structures: thoracic duct, esophagus and pharynx, and larynx and trachea. Glandular structures: thyroid, parathyroid, submandibular. Fascia: superficial and deep cervical fascia.

Anatomy: Neck Zones

Anatomy: Neck Zones Zone I: sternal notch – cricoid cartilage Proximal subclavian, vertebral, carotids; lung apices, trachea, esophagus, thoracic duct, glands Zone II: cricoid – angle of mandible Carotid, vertebrals, trachea, larynx, esophagus, cord, vagus/ recurrent laryngeal Zone III: above angle of mandible Pharynx, salivary glands, distal carotid/ vertebrals, cranial nerves Zone II injuries = most common, best prognosis. Easiest anatomy to expose, apply pressure, control vascular injury. Zone I = highest mortality due to intrathoracic injury (hemothorax, pneumothorax, aortic injury are common).

Anatomy: Triangles Anterior and posterior triangles of the neck : separated by the sternocleidomastoid muscle (SCM): Anterior triangle, defined: Anteriorly – by midline Posteriorly – by SCM Superiorly – by mandible Posterior triangle, defined: Anteriorly – by SCM Inferiorly – by the clavicle Posteriorly – by the anterior border of the trapezius muscle Anterior: easier access

Anatomy: Triangles Anterior triangle structures: Carotid artery Internal jugular vein Vagus nerve Thyroid gland Larynx Trachea Esophagus Posterior triangle structures: Subsclavian artery Brachial plexus Anterior triangle has many more vital structures, yet provides an easier access

Anatomy: Fascial Planes Platysma: superficial muscle that overlaps the sternocleidomastoid Covers anterior triangle completely Covers anteroinferior aspect of posterior triangle Critical landmark in injury diagnosis Deep Cervical Fascia: Pretracheal portion communicates with mediastinum May lead to mediastinitis Platysma is a broad sheet arising from the fascia covering the upper parts of the pectoralis major and deltoid; its fibers cross the clavicle, and proceed obliquely upward and medially along the side of the neck.

Anatomy: Larynx Four basic anatomic components of the larynx: a cartilaginous skeleton, intrinsic and extrinsic muscles, and a mucosal lining.

Anatomy: Larynx Cartilaginous skeleton, which houses the vocal cords, is comprised of the thyroid, cricoid, and paired arytenoid cartilages. These cartilages are connected to other structures of the head and neck through the extrinsic muscles. The intrinsic muscles of the larynx alter the position, shape and tension of the vocal folds

Mechanism of Injury Penetrating Blunt Stangulation For the purpose of this presentation, neck trauma is divided into penetrating, blunt, and strangulation injury.

Neck Trauma: Penetrating Stab Gun shot wounds (GSW) Motor vehicle collisions (MVC) Clothesline / wire Questions Is the platysma penetrated? Stable vs Unstable? Penetrating neck trauma tends to cluster in specific urban areas and is often cared for at Level I trauma centers. At other hospitals, this lack of familiarity and the complexity of the problem make this a “high-risk” situation for both the patient and the provider. Penetrating neck injuries account for 5%-10% of all traumatic injuries and have an overall mortality of up to 10%. Most injuries to the neck are in Zone II (between the cricoid and angle of the jaw). The majority of penetrating neck injuries in the civilian population are produced by knives or firearms. Pathophysiology of penetrating neck trauma varies greatly with mechanism. An powerful assault rifle fired from a distance into the neck region will produce a much more extensive tissue damage than a handgun. Shotgun pellets are generally low-velocity and follow path of least resistance, which results in unpredictable patterns and may lead to distal emboli, such as in heart. Stab wounds may initially look innocuous, but estimation of depth of tract is difficult. Carotid injuries can produce a rapidly expanding hematoma that may distort or occlude the airway. Large lacerations of the jugular venous system can generate an air embolism, causing hypotension and respiratory distress. Follow the little metal fragments: they go in the left maxillary sinus, turn 90 degrees when the base of the skull is hit, and track down the neck.

Neck Trauma: Blunt Blunt: Much more rare MVC (especially unrestrained) Assault Hanging Clothesline accident Sports injury Much more rare Symptoms may be minimal or delayed Causes 3-10% of all cervical vascular injury Blunt neck trauma is less frequent and dramatic, yet it is equally life-threatening. While vascular injuries predominate in penetrating trauma, airway injuries prevail in blunt trauma. Common mechanisms include a motor vehicle collision involving an unrestrained passenger decelerating against the dash (“the padded dash syndrome”), a shoulder harness creating shearing injury to the neck, and blunt neck trauma secondary to airbag deployment, clothesline, and bicycle handlebar injuries. The neck’s complex framework of supporting fascial planes, musculature, and cartilage can result in minimal physical findings and delayed complications. s/p high speed MVC. Old cervical fusion. Now with complete spinal cord transection. Classic symptoms include dysphonia, hoarseness, dysphagia, dyspnea, pain, hemoptysis, and stridor.

Neck Trauma: Strangulation Hanging Clothesline accident Severe hoarseness and stridor signal impending airway obstruction Death from three mechanisms: Injury to the spinal cord or brain stem Mechanical constriction of the neck structures Cardiac arrest

Evaluation Patients with signs of significant neck injury and hemodynamic instability will require prompt exploration. However, initial assessment and management of the patient should be carried out according to ATLS principles. The major initial concern in any patient with a penetrating neck wound is early control of the airway.

Evaluation A characteristic of neck injuries is rapid airway distortion with obstruction due to edema and hematoma, and often difficult intubation. The key to management is early intubation. The route of intubation must be considered carefully in these patients since it may be complicated by distortion of anatomy, hematoma, dislodging of clots, laryngeal trauma, and a significant number of cervical spinal injuries. These patients should be intubated as soon as possible, with appropriate neck protection.

Evaluation Anatomic zone Structures at risk, ease of access, hemorrhage control Signs, symptoms: vascular, laryngeal, tracheal disruption Vascular: active bleed, expanding hematoma, carotid bruit Tracheal: stridor, bubbling bleed, voice changes, dyspnea, subcutaneous emphysema Esophageal: dysphagia Signs and symptoms may be divided into major and minor. Major signs and symptoms are suggestive of significant airway injury. These major diagnostic criteria are: 1. Subcutaneous emphysema (which may develop some time after the initial injury); 2. Dyspnea; 3. Stridor; and 4. Inability to tolerate the supine position. Minor diagnostic criteria include local swelling and tenderness, hoarseness of voice, dysphagia and hemoptysis.

Here is a typical algorithm for evaluation of penetrating neck trauma Here is a typical algorithm for evaluation of penetrating neck trauma. Notice the first step after determining that the pt is unstable? “Secure the airway”

Airway Management Intubating because of Acutely Failed Anatomy or Hemodynamic Instability Can’t just wake the patient up Once the decision to RSI has been made, the patient is committed to a surgical airway if other means to secure airway fail

Airway Management Two difficult questions to answer: When? How?

Airway Management Earlier intubation is easier intubation… Signs & Symptoms: respiratory distress blood/ secretions sub-Q air tracheal shift altered mental status1 Injury: Consider intubating asymptomatic patient if expanding hematoma, GSW to neck1,2 1Eggen JT. J Emerg Med 1993:11(4):381-85. 2Walls RM. J Emerg Med 1993:11(4):479-80. The ultimate goal of airway management in any type of neck injury is to secure is as soon as necessary and before doing so becomes next to impossible. This is especially true in penetrating trauma, where rapid airway distortion with obstruction due to edema and hematoma can in minutes obliterate any remaining tracheal opening. The major initial concern in any patient with a penetrating neck wound is early control of the airway. The key to management is early intubation. The route of intubation must be considered carefully in these patients since it may be complicated by distortion of anatomy, hematoma, dislodging of clots, laryngeal trauma, and a significant number of cervical spinal injuries. These patients should be intubated as soon as possible, with appropriate neck protection.

Method of Securing Airway If no indication of laryngeal injury: Orotracheal intubation, RSI Highest success rate, fewest complications3, 4 If suspected / obvious laryngeal injury: If maintaining airway  Surgical airway in OR Blunt laryngeal trauma  Awake fiberoptic5 Open laryngeal injury  Direct intubation of distal segment5 3Mandavia DP. Ann Emerg Med 2000;35(3):221-225. 4Shearer VE. Ahesth Analg 1993;77(6):1135-1138. 5Walls RM. Emerg Med Clin North Am;16(1):45-61. Specific method of securing the airway in these patients has always been a controversial topic, with different institutions and regions having different “first choice” techniques, based on their local experiences, protocols and support mechanisms. Even here in Baltimore, what we do at Shock Trauma Center may not be accepted as the universal Golden Standard by other institutions. What I present here is largely our experience. Penetrating neck injuries are among the most difficult airway cases to manage, but a recent literature search of airway management in the setting of penetrating neck injury revealed only 3 studies specifically addressing this topic since 1969. Distorted anatomy and risk of clot dislodgement make blind nasotracheal intubation more risky. Bloody secretions make fiberoptic intubation more time consuming, challenging.

Open Tracheal Injury

Open Tracheal Injury

Open Tracheal Injury

Alternative Airway Approaches Cricothyrotomy: Not if expanding hematoma Emergent option in tracheal injury pt who is not maintaining airway Percutaneous Transtracheal Jet Ventilation6 6Patel RG. Chest 1999;116: 1689 – 1964. Invasive airway management (eg, cricothyroidotomy) represents the standard approach when orotracheal intubation, by any method, is unsuccessful or contraindicated. Indications for a surgical airway include massive upper airway distortion, massive midface trauma, and inability to visualize the glottis because of heavy bleeding, edema, or anatomic disruption. Cricothyrotomy can be difficult in a patient with anatomical distortion. The procedure is relatively contraindicated if an anterior neck hematoma exists or a laryngeal injury is suspected, but may be the only option in some patients with PNI. If the necessary resources and expertise are readily available, patients whose external landmarks are sufficiently distorted to make cricothyrotomy difficult or impossible are generally intubated awake using a flexible fiberoptic intubating scope. If the clinician suspects partial or complete laryngeal transection, a fiberoptic approach or a tracheostomy inferior to the injury may be necessary. Percutaneous needle transtracheal or cricothyroid jet ventilation can provide oxygen to adult and pediatric patients while arrangements are made to establish a definitive airway. Clinicians must take care to avoid catheter misplacement or dislodgement, which can force air into the tissues and distort normal airway anatomy. There is no evidence to support the use of percutaneous oxygenation in patients with PNI, and the technique is best reserved for small children in whom formal cricothyroidotomy is difficult or impossible.

Airway Risks in Neck Trauma “Clothesline” injury: motorcycle, bicycle, snowmobile vs. wire, tree limb Can transect trachea: mis-alignment or loss of distal limb w/muscle relaxant Zone I: Pneumothorax, hemothorax Hypotension, high O2 requirement, decreased breath sounds Hematomas that are initially hidden and later expand Foreign body in neck Airway deviation / obstruction

Decision Points Concern related to use of muscle relaxants Theoretically, muscle relaxation can potentially convert a partially obstructed airway to a complete obstruction. But… patient’s muscular tone can be more detrimental than helpful when trying to resolve the acute airway emergency. Although extensively used in emergency practice, rapid sequence intubation remains controversial in those with the potential of distorted airway anatomy such as in patients with penetrating neck injuries. Theoretically, muscle relaxation can potentially convert a partially obstructed airway to a complete obstruction; however, endotracheal tube passage is greatly facilitated and the airway can be quickly and definitively secured.

Decision Points Avoid techniques not performed under direct or fiberoptic visualization. Blind placement of an ETT into a lacerated tracheal segment can create a false lumen outside the trachea or convert a partial tracheal laceration into a complete transection. Be prepared for unexpected difficulty. Have available and ready: two suction devices, a range of different sized ETTs, rescue airway devices, and a surgical airway kit (with a surgeon close!) Bag mask ventilation to preoxygenate in preparation for RSI or to reoxygenate following a failed attempt at intubation may force air into injured tissue planes and distort airway anatomy. Although it is appropriate to perform BMV to oxygenate patients when necessary, ventilation should be done as gently as necessary, and with vigilance to ensure it is not creating more harm than benefit. The best method to achieve definitive airway control in the setting of PNI may vary according to clinical circumstances, clinician skill, and hospital resources . Nevertheless, the following concepts generally apply. We recommend a double set-up for patients with PNI in whom orotracheal intubation is attempted. Patients with neck trauma can deteriorate quickly and may have abnormalities that complicate ETT placement but are not apparent externally.

Summary Injury often occult, airway compromise insidious Clothesline injury is highest risk blunt trauma Consider early intubation for expanding hematoma, GSW, transection of platysma RSI, DL usually successful for neck trauma w/o tracheal injury Surgical airway preferred for tracheal injury with distorted anatomy

Questions?

“Learning is the only thing the mind never exhausts, never fears, and never regrets.” Leonardo di ser Piero da Vinci (April 15, 1452 – May 2, 1519)