EM@3AM – Airway Obstruction

Author: Erica Simon, DO, MHA (@E_M_Simon, EM Chief Resident, SAUSHEC, USAF) // Edited by: Alex Koyfman, MD (@EMHighAK, EM Attending Physician, UT Southwestern Medical Center / Parkland Memorial Hospital) and Brit Long, MD (@long_brit, EM Attending Physician, SAUSHEC, USAF)

Welcome to EM@3AM, an emdocs series designed to foster your working knowledge by providing an expedited review of clinical basics. We’ll keep it short, while you keep that EM brain sharp.

A 19-year-old male presents by EMS following an MVC at highway speeds. The patient, the restrained driver of a compact vehicle (driver’s side impact) arrives on a backboard, C-collar in place, with splints supporting what appear to be open fractures of the left distal radius and ulna, and left femur.

VS: BP 101/72, HR 138, T 99.7 Oral, RR 24, SpO2 95% on room air.

Initially oriented on scene, the patient wheels into your trauma bay pale, diaphoretic, and somnolent. The physician at the head of the bed reports a GCS of 6 (E(1)V(1) M(4)).

What’s the next step in your evaluation and treatment?

Answer: Airway Obstruction^1-4

• Etiologies:¹ Numerous (lists detailed below offer examples and are not all-encompassing):
  • Upper airway obstruction => tongue (semi-conscious/obtunded patient), angioedema, malignancies, foreign bodies, vascular rings, infectious etiologies (e.g. – epiglottitis, bacterial tracheitis, etc.), tracheomalacia, tracheal stenosis, inflammatory conditions (Wegener’s), trauma (expanding hematoma), etc.
  • Lower airway obstruction => COPD, asthma, bronchiectasis, bronchomalacia, infectious etiologies (pneumonia, TB), foreign bodies, malignancies, etc.

• Presentation:^2,3 Varies according to etiology:
  • Upper airway obstruction => coughing, muffled voice, inspiratory stridor, tripod position, inability to tolerate secretions
  • Lower airway obstruction => expiratory wheezes, crackles, rhonchi
  • Patients with central airway obstruction frequently present with increased work of breathing (retractions and/or abdominal breathing), and/or hypoxia.

• Evaluation and Treatment:^3,4
  • Perform an airway assessment: ability to speak and swallow is reassuring.
    • Inability to tolerate secretions, inability to protect the airway (AMS +/- GCS < 8), or inability to maintain SpO2 by non-invasive means => definitive airway management.
    • Unable to intubate (unable to perform airway rescue with supraglottic device) or unable to ventilate =>
      • Age > 10 years: cricothyrotomy: cricothyrotomy kit with #4 cuffed tracheal tube or scalpel with 6.0 cuffed ETT (or largest that will fit).
      • Age < 10 years: temporization with transtracheal jet ventilation: placement of a 12 to 16 gauge angiocatheter and anesthesia consultation for definitive management.⁴
    • Hemodynamically unstable patient => obtain a definitive airway +/- ENT consult for bronchoscopy if previous medical history unknown => may diagnose and/or treat the underlying etiology.
    • Hemodynamically stable patient who is tolerating his/her secretions and protecting his/her airway => perform imaging and consultation (CXR vs. CT vs. ENT consult for bronchoscopy vs. pulmonary consult for PFTs) as directed by the history and physical.

• Pearls:³
  • Look for a LEMON => Factors, in addition to airway obstruction (“O”), that increase the difficulty in obtaining a definitive airway:
    • L – Look externally: micrognathia, facial trauma, etc.
    • E – Evaluate: 3-3-2 rule
    • M – Mallampati score
    • O – Signs of obstruction
    • N – Neck mobility decreased: rheumatoid arthritis, ankylosing spondylitis, possible C-spine injury, etc.

References:

1. Martin R, Meredith W. Management of Acute Trauma. In Sabiston Textbook of Surgery. Philadelphia, Saunders Elsevier. 2017; 16:407-488.
2. Hill N. Acute Ventilatory Failure. In Murray and Nadel’s Textbook of Respiratory Medicine. 6^th ed. Philadelphia, Elsevier Saunders. 2016; 99: 1723-1739.e5.
3. Carlson J, Wang H. Noninvasive Airway Management. In Tintinalli’s Emergency Medicine: A Comprehensive Study Guide. 8^th ed. New York, McGraw-Hill. 2016.
4. Cabel J. Percutaneous Transtracheal Jet Ventilation. In Reichman E, Simon R. eds.Emergency Medicine Procedures. New York, McGraw-Hill. 2004.

For Additional Reading:

The Difficult Airway: Common Errors During Intubation:

The Difficult Airway: Common Errors During Intubation

The Sphincter Series: A Scary Airway Review

The Sphincter Series: A Scary Airway Review