Clinical Tools

Difficult Airway Algorithm

EXIT

Plan A: Face Mask Ventilation and Intubation

[1/11]

Plan A: Face Mask Ventilation and Intubation. Optimize patient position (ramped/sniffing), ensure adequate preoxygenation, confirm adequate neuromuscular blockade before attempting laryngoscopy.

Laryngoscopy Attempts

[2/11]

Direct or video laryngoscopy. Maximum 3 attempts (plus 1 additional attempt by a more experienced provider). Between attempts: reposition head/neck, change blade type or size, use bougie or stylet, apply external laryngeal manipulation (BURP/bimanual).

Confirm Intubation

[3/11]

If intubation successful: confirm endotracheal tube placement with continuous waveform capnography. Auscultate bilaterally. Secure tube.

Plan B: Supraglottic Airway Device

[4/11]

Plan B: Supraglottic Airway Device (SGA). Insert a second-generation SGA (e.g., ProSeal LMA, i-gel, LMA Supreme). Ensure appropriate size selection.

Confirm SGA Ventilation

[5/11]

Confirm adequate ventilation through the SGA with continuous waveform capnography and adequate tidal volumes.

Decision Point After Successful SGA

[6/11]

If SGA ventilation is successful, decide among three options: (1) wake the patient if surgery is elective, (2) proceed with surgery via the SGA, or (3) intubate through the SGA using a fiberoptic bronchoscope.

Plan C: Face Mask Ventilation

[7/11]

Plan C: Face Mask Ventilation. Use two-person mask ventilation technique. Insert oropharyngeal airway (OPA) and/or nasopharyngeal airway. Apply jaw thrust. Consider repositioning.

Consider Waking the Patient

[8/11]

Consider waking the patient if face mask ventilation is adequate and the surgery is elective. Administer sugammadex if rocuronium was used. Plan for awake intubation technique.

Plan D: Emergency Front-of-Neck Access (eFONA)

[9/11]

Plan D: Emergency Front-of-Neck Access (eFONA). This is a Cannot Intubate, Cannot Oxygenate (CICO) situation. Declare "CICO Emergency" to the entire team. This is a life-threatening emergency requiring immediate surgical airway.

Scalpel-Bougie-Tube Cricothyroidotomy

[10/11]

Scalpel-bougie-tube technique: palpate the cricothyroid membrane (CTM), make a transverse stab incision through skin and CTM, rotate scalpel blade 90 degrees (sharp edge caudally), slide a bougie alongside the blade into the trachea, railroad a size 6.0 cuffed endotracheal tube over the bougie, inflate cuff, confirm placement with waveform capnography.

Alternative: Needle Cricothyroidotomy

[11/11]

Alternative: needle cricothyroidotomy with high-pressure jet ventilation (e.g., Ravussin needle or large-bore cannula with jet ventilator). This technique has a higher complication rate (barotrauma, subcutaneous emphysema, kinking) and is less reliable than the scalpel technique.

Source: ASA 2022, DAS 2015

Limitations

  • This protocol is a reference aid and does not replace clinical judgment.
  • This algorithm assumes an unanticipated difficult airway in an anesthetized patient. Awake intubation remains the gold standard when difficulty is anticipated.
  • Equipment availability varies by institution.
  • Front-of-neck access (eFONA) is a rare procedure and regular training is essential.

References

  1. Apfelbaum JL, et al. 2022 American Society of Anesthesiologists Practice Guidelines for Management of the Difficult Airway. Anesthesiology. 2022;136(1):31-81.
  2. Frerk C, et al. Difficult Airway Society 2015 guidelines for management of unanticipated difficult intubation in adults. Br J Anaesth. 2015;115(6):827-848.
  3. Cook TM, et al. Major complications of airway management in the UK: results of the Fourth National Audit Project of the Royal College of Anaesthetists (NAP4). Br J Anaesth. 2011;106(5):617-631.