External Validation of the MASCAN Score for the Classification of Difficult Mask Ventilation

Alert documented in patients health records by the airway operator following facemask ventilation

Impossible facemask ventilation observed after induction of anesthesia (absence of end-tidal carbon dioxide measurement and lack of perceptible chest wall movement despite airway adjuvants and additional personnel after adequate neuromuscular blockade)

Best capnography waveform achieved during facemask ventilation (grade A-D)

Optimization manouvers such as oral airway, jaw-thrust or two-handed grip used as documented facemask ventilation

Leak fraction (leak volume/ tidal volume) during facemask ventilation

Tidal volume during facemask ventilation (ml)

Senior anaesthetist taking over facemask ventilation as documented after facemask ventilation

Observed during airway management (before/ after facemask ventilation)

Manual or controlled ventilation applied by the airway operator

Observed during mask ventilation (to manual or controlled)

Multiple tracheal intubation attempts documented after tracheal intubation

Observed difficult laryngoscopy with restricted glottis view documented after tracheal intubation

Successful tracheal intubation with only one attempt observed during tracheal intubation

Observed during airway management

Observed during airway management

Grading of the best view obtained using landmarks (6-stages)

Grading of the best view obtained during laryngoscopy (%)

Classification of difficult (video-)laryngoscopic intubation (total score -1 to 5)

First-choice tracheal intubation technique unsuccessful

Observed during airway management (%)

Observed during facemask ventilation (%)

Laryngospasm, bronchospasm, larynx trauma, airway trauma, soft tissue trauma, oral bleeding, edema, dental damage, corticosteroid application, accidental esophageal intubation, aspiration, hypotension or hypoxia

Recommendation issued by the airway operator after airway management for either awake tracheal intubation, camera-assisted intubation, direct laryngoscopy or other techniques

Anaesthesia alert card issued by the airway operator after airway management

Anaesthesia alert card issued by the airway operator after airwaymanagement

"Difficult tracheal intubation alert" issued by the airway operator after tracheal intubation in health records