Airway ManagementFor 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

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

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

Anterior triangle structures:

Carotid artery

Internal jugular vein

Vagus nerve

Thyroid gland

Larynx

Trachea

Esophagus

Posterior triangle structures:

Subsclavian artery

Brachial plexus

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

QuestionsIs 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

Evaluation

Evaluation

Anatomic zoneStructures 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

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

Airway Management

Two difficult questions to answer:

When?

How?

Airway ManagementEarlier 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. Ahesth Analg 1993;77(6):1135-1138.

5Walls RM. Emerg Med Clin North Am;16(1):45-61.

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.

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, hemothoraxHypotension, high O2 requirement, decreased breath sounds

Hematomas that are initially hidden and later expand

Foreign body in neckAirway deviation / obstruction

Decision PointsConcern 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 PointsAvoid 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

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)