Airway Management
Airway items test prediction, a structured failed-airway plan and the exact sequence when oxygenation fails. Know the ASA and Difficult Airway Society progression: Plan A laryngoscopy (maximum 3 + 1 attempts), Plan B supraglottic airway, Plan C face-mask ventilation, Plan D front-of-neck access.
Prediction
- Mallampati III–IV, mouth opening under 3 cm, thyromental distance under 6.5 cm, upper lip bite test class III, cervical immobility, OSA.
- Predictors differ for laryngoscopy, supraglottic rescue and mask ventilation - items deliberately mix them.
- Anticipated difficult airway: awake fibreoptic intubation or awake tracheostomy under local anaesthesia; never a paralysed rapid sequence induction.
Optimising the first attempt
- Preoxygenation for 3 minutes of tidal breathing or 8 vital capacities, targeting end-tidal O₂ above 90%; add nasal apnoeic oxygenation.
- Video laryngoscopy first for predicted difficulty; bougie or stylet; optimal external laryngeal manipulation; ramped position in obesity.
- Rapid sequence: ketamine 1–2 mg/kg (or propofol if haemodynamically stable) with rocuronium 1.2 mg/kg.
Worked example
A 45-year-old with a spreading neck abscess, trismus of 2 cm and inspiratory stridor at rest. This is an anticipated difficult airway with impending obstruction: keep spontaneous ventilation, call senior help early, and perform awake fibreoptic intubation or an awake surgical airway in theatre with ENT present. Neuromuscular blockade would convert a partial obstruction into a complete one.
Traps
Making repeated supraglottic attempts instead of declaring failure; confusing 'cannot intubate, can oxygenate' with the emergency front-of-neck pathway (scalpel–bougie–tube through the cricothyroid membrane); giving succinylcholine to a patient with a potentially obstructing lesion.