Difficult Airway Algorithm
Kristin Barkley, DNP, CRNA
Quick Facts
- A difficult airway: difficulty with face mask/SGA ventilation, laryngoscopy/intubation, extubation, or invasive airway.
- A failed airway: inability to intubate despite multiple attempts by multiple anesthesia providers.
- Difficult Airway Society data: failed airway occurs in 0.045–0.35% (most often obstetric patients or known difficult cases).
- Clinical decisions depend on patient assessment and history:
- Proceed with routine induction and intubation
- Awake intubation
- Planned invasive airway
- Following an algorithmic strategy with preparation improves outcomes.
Procedure Guide
Anticipated Difficult Airway
- Assessment: physical exam, history, anesthetic factors, surgical/diagnostic findings.
- Optimization:
- Semi-Fowler position to improve FRC
- Preoxygenate (tight mask, high-flow nasal cannula)
- Sniffing or ramped position
- Personnel: experienced staff immediately available.
- Equipment: difficult airway cart, know what is available and how to use it.
Anticipated Difficult Airway – Awake Intubation
- Indications: anticipated difficulty with intubation AND one or more of:
- Difficult ventilation (facemask or SGA)
- High aspiration risk
- Cannot tolerate apneic episodes
- Expected difficulty with emergent invasive airway rescue
- Requires patient cooperation.
- Approaches: regional, local, minimal-to-moderate sedation.
- Maintain spontaneous breathing.
- Techniques:
- Flexible bronchoscope
- Video/direct laryngoscopy
- Combined approaches
- Retrograde wire-guided intubation
Elective or Emergent Invasive Airway
- Cricothyrotomy (surgical, needle, large-bore cannula)
- Surgical or percutaneous tracheostomy
- Retrograde wire-guided intubation
- Rigid bronchoscopy
- ECMO if invasive approaches fail/unavailable
Unanticipated Difficult Airway
- Call for help immediately.
- Oxygenate between attempts; use adjuncts as needed.
- If cannot ventilate:
- Prepare for emergency invasive airway.
- Continue optimized attempts while preparing surgical airway.
- Follow cognitive aids/algorithms.
- Consider waking patient and restoring spontaneous breathing.
- Noninvasive vs invasive techniques:
- Have a progression plan of devices.
- Use combined techniques as needed.
- Track time, attempts, patient stability.
Signs of Difficult Ventilation
- Poor mask seal/leaks
- Poor chest rise
- Absent or inadequate breath sounds
- Poor gas exchange (SpO₂/ETCO₂ changes)
- Hemodynamic instability
- Rule out laryngospasm or bronchospasm
Rule of 3 Attempts
- Limit attempts within each technique class:
- Face mask ventilation
- Supraglottic airway
- Tracheal tube intubation
- Allow one additional attempt by a more experienced provider.
- Multiple failed attempts increase risk of trauma, edema, bleeding.
Examples
- Face mask attempt: OPA/NPA, two-handed technique.
- SGA attempt: Adjust size, design, reposition, type.
- Tracheal tube attempt: Video laryngoscopy, alternate blades, flexible bronchoscope, introducers, lighted stylet, external laryngeal manipulation.
SCOPe Guide
Strategies – Difficult Airway Algorithm
ASA Difficult Airway Guidelines (2022):
- Failed intubation → optimize oxygenation.
- If cannot ventilate with facemask or SGA → emergency invasive airway.
- Alternate approaches/adjuncts may be tried while preparing for surgical airway.
- Consider waking the patient when feasible.
Awake Intubation Algorithm
- If awake intubation fails:
- Call for help, optimize oxygenation.
- Postpone if possible or use alternate awake technique.
- Elective invasive approach if required.
- If unstable or cannot postpone → emergency invasive airway.
Pearls
- Plan: Assess if you can intubate, ventilate, or neither.
- Oxygen: Preoxygenate, oxygenate between attempts, avoid exhausting oxygen reserve.
- Resources: Know where difficult airway cart is, what it contains, and how to use equipment.
- Help: Call for experienced personnel early.
- Algorithm: Use visual aids to prevent loss of situational awareness.
- Limit attempts to prevent airway trauma.
- Always suction, reposition, and optimize anesthetic depth between attempts.
- Rule of 3: No more than 3 attempts in each technique category.
Media
References
- Elisha S, Heiner JS, Nagelhout JJ. Nurse Anesthesia. 7th ed. Elsevier; 2023.
- Apfelbaum JL, Hagberg CA, Connis RT, et al. 2022 American Society of Anesthesiologists Practice Guidelines for Management of the Difficult Airway. Anesthesiology. 2021;136:31-81. doi:10.1097/ALN.0000000000004002.
Media Attributions
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