Randomised controlled trial of intubation with the McGrath® Series 5 videolaryngoscope by inexperienced anaesthetists

Background. The McGrath (R) Series 5 videolaryngoscope might reduce the incidence of unexpected difficult tracheal intubation. If it also performs as well as a standard laryngoscope during uncomplicated intubations, there would be an argument for the McGrath (R) to become the laryngoscope of choice in higher risk settings, such as rapid sequence induction by inexperienced anaesthetists. Therefore, we compared the McGrath and the Macintosh laryngoscopes during routine tracheal intubation performed by inexperienced anaesthetists.

Methods. Single-blind randomized controlled trial with 120 adult patients allocated to intubation by first-year anaesthetic trainees, using a McGrath (R) or Macintosh laryngoscope. The primary outcome was time to intubation. Secondary outcomes were quality of view at laryngoscopy and evidence of differential learning between using the two laryngoscopes. A Cox proportional hazards model was used to determine the effect of the laryngoscopes on time to intubation.

Results. Duration of intubation was significantly longer (P<0.001) in the McGrath (R) group [median (IQR); 47.0 (39.0-60.0) vs 29.5 (23.0-36.8) s]. There were no significant differences in other outcomes, including grade of laryngoscopy view, visual confirmation of tube placement, number of laryngoscopies, or complications (oesophageal intubation, hypoxaemia, and airway trauma). There was no differential learning effect.

Conclusions. There were no advantages to using the McGrath (R) laryngoscope for uncomplicated tracheal intubation and duration of intubation was longer, so it should not be used as a first-line laryngoscope instrument by inexperienced anaesthetists.