Background

We hypothesized that the use of the channeled King Vision™ and Airtraq® would shorten the time for tracheal intubation compared with the Macintosh or GlideScope® laryngoscopes in patients with normal airways.

Methods

Eighty-six patients were randomly assigned to intubate the trachea using either the Macintosh (N.= 22), Glidescope®(N.= 21), Airtraq®(N.= 21), or King Vision™(N.= 22) laryngoscope. The primary outcome was the time to tracheal intubation. Secondary outcomes included the laryngoscopic view, numbers of laryngoscopy attempts, first-pass success rate, optimization maneuvers, ease of intubation, and postoperative sore throat.

Results

Compared with the Macintosh and GlideScope®, the use of the channeled videolaryngoscopes had significantly longer times to tracheal intubation (mean times: Airtraq® 44 s [95% CI: 39.6 to 46.7]; King Vision™ 34.5 s [95% CI: 33.1 to 40.2]; Macintosh 20 s [95% CI: 19.7 to 26.7]; GlideScope® 27.9 s [95% CI: 25.1 to 30.7], P< 0.002) and caused less mucosal trauma (P= 0.006). The King Vision™ is slightly faster than the Airtraq®(P= 0.035). Compared with the Macintosh and the Airtraq®, the GlideScope® was easier to use (P< 0.001). The 4 groups had comparable glottis views, number of laryngoscopy and optimising manoeuvres and first attempt success rate. The Airtraq® and King Vision™ had a lower incidence of sore throat than with the Macintosh or GlideScope®(P= 0.001). No patient had failed intubation.

Conclusions

The King Vision™ and Airtraq® require longer intubation times, as primary outcome, and cause less sore throat than the Macintosh and GlideScope® when used by anesthesiologists with limited experience in patients with normal airways. Our conclusion is difficult to extrapolate to the expert anesthesiologists who are using videolaryngoscopes on a regular basis.