A comparison of the AMBU ISCOPE and Macintosh laryngoscopes: first experience with a new device for tracheal intubation: a manikin study.

CONTEXT: Video laryngoscopes achieve laryngeal visualisation through indirect imaging using video cameras that look around the curve of the tongue. The new AMBU ISCOPE intubation device combines features from the laryngeal mask airway with video laryngoscopy enabling visual control of tracheal intubation without the use of a stylet.

OBJECTIVE: We hypothesised that the AMBU ISCOPE would shorten the time taken to intubate a manikin compared to the Macintosh laryngoscope.

DESIGN: Crossover study.

SETTING: University hospital in Denmark.

STUDY PERIOD: April 2011.

PARTICIPANTS: We enrolled 36 trainees (19 nurse anaesthetists and 17 anaesthetists) with a median of 7 months of experience in anaesthesia (interquartile range 5 to 7.5 months).

INTERVENTION: Tracheal intubation of a manikin, the Laerdal Airway Management Trainer, using either the AMBU ISCOPE, a new intubation conduit, or a conventional Macintosh laryngoscope. Every trainee performed three tracheal intubations with each device.

MAIN OUTCOME MEASURES: The primary end-point was time to intubation. Secondary end-points were Cormack & Lehane grade and dental contact.

RESULTS: Median time to tracheal intubation was 33.5 s using a Macintosh laryngoscope and 41.5 s using the AMBU ISCOPE device (P = 0.008). In both groups, 97% of intubations were successful. Ninety-seven percent of laryngeal visualisations achieved using the AMBU ISCOPE device were reported to be Cormack & Lehane grade 1 versus 57% for the Macintosh laryngoscope (P = 0.0001).

CONCLUSION: Tracheal intubation time was significantly longer in trainees using the AMBU ISCOPE intubation device compared to a Macintosh laryngoscope, but with a difference of only 8 s. Laryngeal visualisation was significantly better using the AMBU ISCOPE device, but success rates for intubation were the same.