Figure 51-1. Difficult Airway Algorithm
Reproduced with permission from Practice guidelines for management of the difficult airway: an updated report by the American Society of Anesthesiologists Task Force on Management of the Difficult Airway. Anesthesiology. 2003;98:1269.
Characteristics of Various Tools Used to Secure Difficult Airways
|Bougie||Useful for grade 2 or 3 view, inexpensive||No visualization of cords, blind insertion may cause trauma|
|Fiber-optic||Confirmation of tube depth, avoidance of neck mobilization, can be performed awake, high chance of success with skilled operator||Time consuming, no rapid sequence, cost of equipment, success rate operator dependent|
|Laryngeal mask airway (LMA)||Ease of use, lower resistance airway, less chance of dental injury, reduced sore throat, reduced hemodynamic and IOP changes||May be unsafe in procedures requiring head movement or position other than supine, does not prevent aspiration, not protective against laryngospasm|
|Intubating LMA (i.e., Fastrach, AirQ)||Ease of use, ability to ventilate allows time to intubate||Success not guaranteed, no visualization of vocal cords, potential esophageal, pharyngeal, or laryngeal trauma due to blind insertion, more minor complications than standard LMA (sore throat, difficulty swallowing), no rapid sequence|
|Video laryngoscope (i.e., Glidescope, McGrath)||May help minimize neck movement, ease of obtaining view of cords, may be used for rapid sequence, useful for teaching||ETT may be difficult to pass, risk of failure in patients with cervical deformity|
|Airtraq||Ease of use, ability to visualize cords, reduced hemodynamic changes, reduced cervical spine motion, disposable||Cost, requires good mouth opening, single blade size|
- Invasive procedure requiring multiple items
- Time consuming
The gum elastic bougie is a ˜25″ long flexible stylet with angled tip.
Indications: poor grade laryngoscopy, suspected cervical spine injury.
Contraindications: contraindication to laryngoscopy, inaccessible oral cavity.
- Perform standard laryngoscopy, attempting to identify arytenoids
- Lubricate bougie
- Insert angled end of bougie blindly under epiglottis, probing for opening
- Insert until clicks felt along tracheal rings
- If no clicks, continue insertion until resistance felt against smaller airways
- Retract bougie from area of resistance
- Advance endotracheal tube over bougie into trachea without advancing bougie
- Remove bougie and confirm endotracheal tube placement
Indications: difficult airway, avoiding neck extension or mandibular distraction, awake intubation.
Contraindications: bleeding in airway, lack of time, lack of patient cooperation if awake.
Laryngeal Mask Airway (LMA)
Supraglottic ventilatory device consisting of anatomically shaped silicone cuff attached to tube for connection to circuit.
Contraindications: risk of aspiration (GERD, obesity, pregnancy, full stomach, upper abdominal surgery, etc.), facial trauma, pharyngeal obstruction, patients requiring high insufflation pressures, restricted access to airway.