Difficult Airway Algorithm

Advanced Airway Management Decision Tree

Back to Education Center

Difficult Airway Algorithm

Key Principle: Oxygenation Over Intubation

Maintain oxygenation and ventilation at all times

Call for help early and have a backup plan

Airway Management Components

Airway Assessment

LEMON Assessment

Look externally, Evaluate 3-3-2, Mallampati, Obstruction, Neck mobility

Look Externally

  • Facial trauma: Swelling, deformity, bleeding
  • Beard/mustache: May interfere with mask seal
  • Large tongue: May obstruct view
  • Short neck: Limited mobility
  • Morbid obesity: Increased difficulty

Evaluate 3-3-2 Rule

3 Fingers

Mouth opening (inter-incisor distance)

3 Fingers

Hyoid-mental distance

2 Fingers

Thyrohyoid distance

Mallampati Classification

Class I

Soft palate, fauces, uvula, pillars visible

Class II

Soft palate, fauces, uvula visible

Class III

Soft palate, base of uvula visible

Class IV

Hard palate only visible

Interactive Decision Tree

Step 1: Can the patient maintain their airway?

Assess level of consciousness, ability to protect airway

Rapid Sequence Intubation (RSI)

RSI 7 P's

Preparation

  • Equipment check
  • Team briefing
  • Backup plan

Preoxygenation

  • 100% FiO2 for 3-5 minutes
  • High-flow nasal cannula
  • Non-rebreather mask

Premedication

  • Atropine (pediatric)
  • Lidocaine (if reactive airway)
  • Fentanyl (if time permits)

Paralysis

  • Succinylcholine 1.5 mg/kg
  • Rocuronium 1.2 mg/kg
  • Wait for full paralysis

Protection

  • Sellick maneuver
  • Cricoid pressure
  • Prevent aspiration

Placement

  • Direct laryngoscopy
  • Video laryngoscopy
  • Confirm placement

Post-intubation

  • Secure tube
  • Confirm placement
  • Sedation/analgesia

💊 RSI Medications

Etomidate
0.3 mg/kg IV

Induction agent with minimal hemodynamic effects. Good for unstable patients.

Ketamine
1-2 mg/kg IV

Induction agent with bronchodilator properties. Good for reactive airway disease.

Succinylcholine
1.5 mg/kg IV

Depolarizing paralytic with rapid onset and short duration.

Rocuronium
1.2 mg/kg IV

Non-depolarizing paralytic. Longer duration than succinylcholine.

Backup Airway Plans

Plan B: Supraglottic Airways

When direct laryngoscopy fails, use supraglottic airway devices

Laryngeal Mask Airway (LMA)

  • Insert blindly into hypopharynx
  • Inflate cuff to create seal
  • Allows ventilation and oxygenation
  • Can be used as conduit for intubation

i-gel

  • Gel-filled cuff, no inflation needed
  • Good seal and gastric access
  • Easy insertion technique
  • Available in multiple sizes

King LT

  • Dual-lumen design
  • Esophageal and tracheal lumens
  • Gastric decompression capability
  • Good for longer procedures

Plan C: Surgical Airway

When all else fails, perform surgical cricothyrotomy

Surgical Cricothyrotomy

  1. Identify cricothyroid membrane (between thyroid and cricoid cartilages)
  2. Stabilize larynx with non-dominant hand
  3. Make horizontal incision through skin and membrane
  4. Insert tracheal hook to stabilize trachea
  5. Insert endotracheal tube or tracheostomy tube
  6. Inflate cuff and confirm placement

Needle Cricothyrotomy

  1. Insert large-bore needle (14G) through cricothyroid membrane
  2. Attach syringe and aspirate air to confirm placement
  3. Thread catheter over needle
  4. Remove needle and secure catheter
  5. Connect to high-flow oxygen (15 L/min)
  6. Provide 1-second insufflation every 5 seconds

Difficult Airway Key Principles

  • Oxygenation over intubation - maintain SpO2 > 90%
  • Call for help early when difficulty is anticipated
  • Have a backup plan and know when to move to it
  • Use video laryngoscopy when available
  • Practice surgical airway techniques regularly
  • Document airway difficulty for future encounters

Reference Information

Source: Difficult Airway Society (DAS) Guidelines

Guidelines: 2015 DAS Guidelines for Management of Unanticipated Difficult Intubation

Note: Regular practice and simulation training are essential for maintaining airway skills.