What is the recommended approach for managing a difficult airway?

Difficult Airway Management

For any known or suspected difficult airway, you must have a preplanned strategy that includes thorough preoxygenation, video laryngoscopy as first-line, immediate availability of specialized equipment, and a skilled assistant—with awake intubation strongly preferred when both difficult intubation and difficult ventilation are anticipated. 1, 2

Pre-Intubation Assessment

Rapidly assess four critical factors even in urgent situations 2:

• Difficult laryngoscopy/intubation risk: Evaluate Mallampati score, thyromental distance (<6 cm problematic), sternomental distance, interincisor distance (<3 cm problematic), mouth opening, ability to prognath, head/neck mobility, prominent upper incisors, and upper lip bite test 1, 2

• Difficult mask ventilation risk: Assess facial features including presence of beard, neck circumference (>43 cm problematic), ratio of neck circumference to thyromental distance, and body mass index 1, 2

• Aspiration risk: Consider full stomach status, recent oral intake, pregnancy, bowel obstruction, and gastroesophageal reflux 2

• Rapid desaturation risk: Identify obesity, pregnancy, pediatric patients, restrictive lung disease, and critical illness 2, 3

Team and Equipment Preparation

Ensure immediate availability of a portable difficult airway cart before induction 1, 2:

• Video laryngoscopy equipment (both hyperangulated and standard geometry blades) 1, 2
• Flexible bronchoscope for awake or asleep fiberoptic intubation 1, 2
• Multiple supraglottic airways (LMA, i-gel, etc.) 1, 2
• Cricothyrotomy kit with scalpel, bougie, and small endotracheal tube 1, 2
• Adjuncts including bougies, stylets, and alternative endotracheal tubes 1

Have a skilled assistant immediately available and ensure the most experienced operator performs the intubation 1, 2

Patient Positioning and Preoxygenation

Position the patient head-up 25-30° when tolerated to improve upper airway patency and functional residual capacity 2:

• Use "sniffing position" (lower cervical flexion, upper cervical extension) for optimal laryngoscopic view 2
• In obese patients, ramped positioning with shoulders elevated is superior 2

Preoxygenate thoroughly for 3 minutes using tight-fitting facemask with 100% oxygen at 10-15 L/min, targeting end-tidal oxygen >85% 1, 2:

• Traditional 3-minute tidal volume breathing is more effective than fast-track four maximal breaths in 30 seconds 1
• Consider apneic oxygenation via nasal cannula (5-15 L/min) or high-flow nasal oxygen (up to 70 L/min) during intubation attempts to prolong safe apnea time 1, 4, 3

Decision: Awake vs. Post-Induction Intubation

Choose awake intubation when 1, 2:

• Predicted difficulty with BOTH intubation AND ventilation 2
• Significantly increased aspiration risk with difficult airway 2
• Patient cooperation is possible 1, 2
• Benefits clearly outweigh risks of proceeding after induction 2

Awake intubation technique 1, 2:

• Inform patient of special risks and obtain consent 1
• Provide adequate topical anesthesia and sedation (maintaining cooperation) 2
• Use flexible bronchoscopy or video laryngoscopy for awake technique 1, 2
• Maintain continuous monitoring (ECG, blood pressure, pulse oximetry, end-tidal CO₂) 2

Proceed with post-induction intubation only when 2:

• Adequate mask ventilation is predicted after induction 2
• Success is predicted within maximum three attempts 2
• Benefits are judged to outweigh risks 2

Post-Induction Intubation Protocol

Use video laryngoscopy as first-line technique—it is superior to direct laryngoscopy for difficult airways 1, 2:

• Hyperangulated blades (e.g., GlideScope, McGrath) provide better glottic view in anterior airways 1
• Standard geometry video laryngoscopes allow both direct and video views 1

Limit intubation attempts to avoid laryngeal trauma 2, 5:

• Maximum three attempts by experienced operator 2
• Change technique or equipment between attempts 2
• Consider supraglottic airway after failed attempts 1, 2

Optimize mask ventilation if intubation fails 5:

• Use two-handed mask technique with oral airway 5
• Apply jaw thrust and consider PEEP 1
• Administer neuromuscular blockade to improve mask ventilation if needed 1

Emergency "Cannot Intubate, Cannot Ventilate" Protocol

Call for help immediately when CICV situation is recognized 1, 2:

• Attempt supraglottic airway placement (LMA, i-gel) as rescue ventilation 1, 2
• If supraglottic airway fails or inadequate, proceed immediately to front-of-neck access 2, 6

Perform emergency surgical cricothyrotomy by individual trained in invasive techniques 1, 2:

• Scalpel-bougie-tube technique is preferred surgical approach 6
• Needle cricothyrotomy with jet ventilation is temporary measure only 1, 2
• Do not delay surgical airway if severe hypoxia develops 5, 6

Confirmation of Tube Placement

Confirm tracheal intubation using waveform capnography—this has 100% sensitivity and specificity 2:

• End-tidal CO₂ monitoring is the most reliable confirmation method 2
• Colorimetric CO₂ detectors acceptable as initial confirmation when waveform unavailable 2
• Do not rely solely on auscultation or chest rise 2

Extubation Strategy

Have a preformulated extubation strategy for every difficult airway 1:

• Consider awake extubation versus extubation before return of consciousness 1
• Evaluate for factors producing adverse impact on ventilation after extubation 1
• Consider short-term use of airway exchange catheter as guide for expedited reintubation 1
• Provide supplemental oxygen after extubation 1

Post-Procedure Documentation and Follow-Up

Document the difficult airway encounter comprehensively 1, 2:

• Inform patient of airway difficulty encountered and implications for future care 1
• Provide written documentation to patient and in medical record 1
• Consider notification bracelet or emergency notification service registration 1
• Evaluate patient for potential complications including edema, bleeding, tracheal perforation, pneumothorax, and aspiration 1, 7

Critical Pitfalls to Avoid

Do not make multiple repeated intubation attempts—this causes laryngeal edema and hemorrhage 2, 5:

• Limit to three attempts maximum 2
• Change technique between attempts 2

Do not delay calling for help in CICV situations 2, 5:

• Call for help at first recognition of difficulty 2
• Proceed rapidly to surgical airway if noninvasive methods fail 5, 6

Do not underestimate the importance of optimized mask ventilation 5:

• Adequate mask ventilation reduces CICV incidence 5
• Use two-person technique and adjuncts liberally 5