DAS Guidelines on Airway Management
The Difficult Airway Society (DAS) guidelines provide a structured, stepwise approach to airway management through four sequential plans (A-D) that prioritize oxygenation and prevention of airway trauma in unanticipated difficult intubation scenarios. 1
Core Structure of DAS Guidelines
The guidelines are organized into four sequential plans:
Plan A: Initial tracheal intubation plan 1
- Focuses on optimizing first attempt at laryngoscopy
- Includes proper positioning, pre-oxygenation, and equipment selection
- Recommends limiting laryngoscopy attempts to three maximum
Plan B: Secondary tracheal intubation plan when Plan A fails 1
- Utilizes supraglottic airway devices (SADs)
- Recommends fibreoptic intubation through SAD
- Limits to two attempts at SAD insertion
Plan C: Maintenance of oxygenation when intubation fails 1
- Focuses on face mask ventilation
- Aims to maintain oxygenation while postponing surgery
- Prepares for awakening the patient
Plan D: Rescue techniques for "can't intubate, can't ventilate" (CICV) situation 1
- Emergency front-of-neck access
- Scalpel cricothyroidotomy is the recommended technique
Key Principles and Recommendations
Pre-Procedure Assessment
- Comprehensive airway evaluation to identify potential difficulties 1
- Assessment should include history, physical examination, and appropriate investigations 1
- Consideration of awake tracheal intubation when difficult airway is predicted 1
Equipment and Preparation
- Availability of difficult airway equipment reduces adverse outcomes 1
- Designated assistant should be available when managing difficult airways 1
- Pre-oxygenation is essential before induction to delay arterial desaturation 1
Intubation Techniques
- Video laryngoscopy is recommended for patients with suspected cervical spine injury 1
- Second-generation SADs are preferred over first-generation devices 1, 2
- Blind techniques using a bougie through SADs have been superseded by video or fiberoptic-guided intubation 2
Documentation and Follow-up
- Detailed documentation of airway difficulties encountered 1
- Patient should be informed about airway difficulties and implications for future care 1
- Follow-up evaluation for potential complications of difficult airway management 1
Recent Updates and Advances
The 2015 DAS guidelines 2 updated the original 2004 guidelines with several important changes:
- Simplified to a single algorithm covering both routine and rapid sequence induction
- Greater emphasis on limiting the number of airway interventions
- Recommendation of videolaryngoscopy over traditional direct laryngoscopy
- Preference for second-generation supraglottic airway devices
- Scalpel cricothyroidotomy as the preferred emergency front-of-neck access technique
Special Considerations
Cervical Spine Injury
- Videolaryngoscopy should be used when possible 1
- Jaw thrust is preferred over head tilt-chin lift for maintaining airway 1
- Semi-rigid collars should be removed (at least the anterior portion) during intubation attempts 1
Awake Tracheal Intubation
- Indicated when difficult airway is predicted 1
- Ideally performed in operating theater environment 1
- Requires proper planning, communication with team members, and appropriate setup 1
Common Pitfalls to Avoid
- Persisting with multiple attempts at intubation despite failure (limit to three attempts) 1, 2
- Failing to call for help early when difficulties arise 2
- Not confirming tracheal intubation with capnography 1
- Inadequate pre-oxygenation before induction 1
- Lack of preparation for "can't intubate, can't ventilate" scenario 1, 2
The DAS guidelines emphasize the importance of maintaining oxygenation throughout airway management, limiting trauma from repeated attempts, having a clear plan for failure, and ensuring proper documentation and follow-up of airway difficulties.