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Airway Management For Neck Trauma Alex Sigalovsky, CRNA. Objectives. Anatomy Classifications Mechanisms Airway Cases Summary. Anatomy of Neck. A complex network of muscles, vessels, and nerves – all supported by fascial planes
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Objectives • Anatomy • Classifications • Mechanisms • Airway • Cases • Summary
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 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 • 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
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
Anatomy: Triangles • Posterior triangle structures: • Subsclavian artery • Brachial plexus • Anterior triangle structures: • Carotid artery • Internal jugular vein • Vagus nerve • Thyroid gland • Larynx • Trachea • Esophagus
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
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
Neck Trauma: Penetrating • Penetrating: > 95% • Stab • Gun shot wounds (GSW) • Motor vehicle collisions (MVC) • Clothesline / wire • Questions • Is the platysma penetrated? • Stable vs Unstable?
Neck Trauma: Blunt • Blunt: • 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
Neck Trauma: Strangulation • 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 • 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
Airway Management • Intubating because of Acutely Failed Anatomy or Hemodynamic Instability • Can’t justwakethe 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.
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. AhesthAnalg 1993;77(6):1135-1138. 5Walls RM. Emerg Med Clin North Am;16(1):45-61.
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.
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.
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.
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
“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)