A comparison of tracheal intubation in the simulated unstable cervical spine: McGrath videolaryngoscope versus Macintosh laryngoscope

INTERVENTION: Intubation with a McGrath videolaryngoscope. Intubation involves passing an endotracheal tube into the trachea to enable ventilation during surgery. Evidence suggests that the McGrath videolaryngoscope provides an improved view of the larynx to enable safe passage of the tracheal tube. Duration of laryngoscope will be approximately 30‐60 secs. Intubation will take place after induction of anaesthesia. CONDITION: Intubation in the setting of potential cervical spine instability PRIMARY OUTCOME: Speed of intubation. This will be measured using a stop‐watch (seconds) by one of the study investigators who is also an anaesthetist. SECONDARY OUTCOME: Incidence of complications will be assessed when one of the study investigators reviews the patient in recovery ie. after they have woken up from surgery. Incidence of difficult tracheal intubation. This will be assessed by the anaesthetist performing the intubation. Difficulty of intubation will be assessed via the intubation difficulty score (IDS) which is a validated measure of the difficulty of intubation. Laryngoscopic view will be assessed by the established Cormack/Lehane grading system. This grading system applies grades to the view depending on how much of the larynx is seen. Success rate of intubation will be calculated by dividing attempts at intubation by successful intubation. INCLUSION CRITERIA: American Society Anesthesia physical status grading system (ASA) 1‐3 patients requiring endotracheal intubation for surgery; English speaking; full frontal dentition