The GlideScope Video Laryngoscope: randomized clinical trial in 200 patients

The GlideScope Video Laryngoscope is a new intubating device. It was designed to provide a view of the glottis without alignment of the oral, pharyngeal and tracheal axes. The aim of the study was to describe the use of the GlideScope in comparison with direct laryngoscopy for elective surgical patients requiring tracheal intubation.

Two hundred patients were randomly assigned to intubation by direct laryngoscopy using a Macintosh size 3 blade (DL, n=100) or intubation using the GlideScope (GS, n=100). Prior to intubation all patients were given a Cormack and Lehane (C&L) grade by a separate anaesthetist using a Macintosh size 3 blade. The patient was then intubated, using direct laryngoscopy or the GlideScope, by a different anaesthetist during which the larynx was inspected and given a laryngoscopy score. Time to intubate was measured.

In the GS group, laryngoscopy grade was improved in the majority (28/41) of patients with C&L grade >1 and in all but one of patients who were grade 3 laryngoscopy (P<0.001). The overall mean time to intubate was 30 (95% CI 28-33) s in the DL group and 46 (95% CI 43-49) s in the GS group. The time to intubate for C&L grade 3 was similar in both groups, being 47 s for the DL group and 50 s for the GS group respectively.

In most patients, the GlideScope provided a laryngoscopic view equal to or better than that of direct laryngoscopy, but it took an additional 16 s (average) for tracheal intubation. It has potential advantages over standard direct laryngoscopy for difficult intubations.