Post on 01-Jan-2016
description
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)