The difficult airway

Predicting the difficult airway

ASA Difficult Airway Algorithm

  • Does not necessary apply to the ED since the patient can always be awakened and case cancelled
    • Cricothyrotomy should always be the last step in patients with failure to oxygen and ventilate with BVM and inability to intubate
    • Straight blade- Miller- may offer better manipulation of a large epiglottis in children or for micrognathia or "buck teeth"

Improving Passive Oxygenation

See Apneic oxygenation

Advanced airway adjuncts

Endotracheal tube introducer (ETI)/Gum Elastic Bougie

  • Higher first pass success when used with direct laryngscope vs. styletted ET tube regardless of whether difficult airway was expected or not [1]
  • Blind orotracheal intubation

Nasal intubation

  • Not as successful but still an option
  • Higher complication rate - bleeding, emesis, and airway trauma

Lighted Optical Stylets

  • High success rate - especially good for trauma, c-spine precautions
  • Use for both reg and nasotrach
  • Lower complication rate
  • Limited by fogging, secretion, recognition of anatomy, cost, and rare provider experience

LMA

  • Can use without muscle relaxants
  • Better than face mask
  • Can be used as bridge to fiberoptic intubation
  • Limited by unreliable seal at peak insp pressure
  • Aspiration risk
  • Mucosal trauma
  • LMA better than endotracheal for paramedics, especially in pediatric patients[2][3]
  • Intubating LMA (LMA-Fastrach) provides the opportunity to convert to a definitive airway after rescue with the supraglottic device

Combitube- esoph obturator

  • Good for nurses and paramedics with limited intubation skill
  • Indicated if difficult airway predicted: cannot see glottis with laryngoscope
  • Reduced risk for aspiration compared to face mask or LMA
  • Can maintain spinal immobilization
  • Large size predisposes to esophogeal dilatation and laceration as a complication

Percutaneous transtracheal ventilation

  • PTV
  • Prefered over crithyrotomy in children up to age 10-12
  • Needle, 16-18ga through cricoid membrane, connected to 50 psi 02[4]
    • Oxygenates well
    • Ventilate through glottis and upper airway - can retain CO2
  • Need adequate oxygen pressure
  • 1 sec insp and 2- 3 sec exp to avoid breath stacking
  • Can use for 30-45 min
  • May cause pneumothorax or barotrauma
  • Contraindications
    • Distorted anatomy
    • Bleeding diathesis
    • Complete airway obstruction

Retrograde Intubation

  • Percutaneous guide wire through cricoid and retrograde intubation over wire
  • Use guide catheter over wire and then ett
  • Need time to set up
  • Risk hematoma, pneumothorax
  • Contraindicated
    • Bleeding
    • Distorted anatomy

Fiberoptic Bronchoscopic Intubation

  • Takes time to set up
  • Good for c-spine injury or awake patient with diff airway
  • Go through nose
  • Use for all ages, can give 02 during procedure thru fiberscope, immediate confirmation of position
  • Limited by secretions, bleeding, poor suction,

Rigid Fiberoptic Laryngoscopes

  • Use for diff airway or spinal immobolization
  • Not as good and longer time to intubate than flex scope

Surgical cricothyrotomy

  • Can get subglottic stenosis
  • Rapid 4 step procedure faster but higher complication rate - cric cart fx
  • Can also do wire guided
  • Long term morbid, mortality similar to tracheostomy

See Also

Airway Pages

Mechanical Ventilation Pages

Video

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References

  1. ↑ Driver, B. E., Prekker, M. E., Klein, L. R., Reardon, R. F., Miner, J. R., Fagerstrom, E. T., … Cole, J. B. (2018). Effect of Use of a Bougie vs Endotracheal Tube and Stylet on First-Attempt Intubation Success Among Patients With Difficult Airways Undergoing Emergency Intubation: A Randomized Clinical Trial. JAMA: The Journal of the American Medical Association, 319(21), 2179–2189.
  2. ↑ Zhu X-Y, Lin B-C, Zhang Q-S, Ye H-M, Yu R-J. A prospective evaluation of the efficacy of the laryngeal mask airway during neonatal resuscitation. Resuscitation. 2011;82(11):1405–1409. doi:10.1016/j.resuscitation.2011.06.010
  3. ↑ Calkins MD, Robinson TD. Combat trauma airway management: endotracheal intubation versus laryngeal mask airway versus combitube use by Navy SEAL and Reconnaissance combat corpsmen. J Trauma. 1999;46(5):927–932
  4. ↑ Beck, E., Kharasch, M., Casey, J., Ochoa, P., Menon, S., Calabrese, N. and Wang, E. (2011) ‘Percutaneous Transtracheal jet ventilation’, Academic Emergency Medicine, 18(5), pp. e38–e38.
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