GlideScope versus flexible fiber optic for awake upright laryngoscopy

We compare laryngoscopic quality and time to highest-grade view between a face-to-face approach with the GlideScope and traditional flexible fiber-optic laryngoscopy in awake, upright volunteers.

This was a prospective, randomized, crossover study in which we performed awake laryngoscopy under local anesthesia on 23 healthy volunteers, using both a GlideScope video laryngoscopy face-to-face technique with the blade held upside down and flexible fiber-optic laryngoscopy. Operator reports of Cormack-Lehane laryngoscopic views and video-reviewed time to highest-grade view, as well as number of attempts, were recorded.

Ten women and 13 men participated. A grade II or better view was obtained with GlideScope video laryngoscopy in 22 of 23 (95.6%) participants and in 23 of 23 (100%) participants with flexible fiber-optic laryngoscopy (relative risk GlideScope video laryngoscopy versus flexible fiber-optic laryngoscopy 0.96; 95% confidence interval 0.88 to 1.04). Median time to highest-grade view for GlideScope video laryngoscopy was 16 seconds (interquartile range 9 to 34) versus 51 seconds (interquartile range 35 to 96) for flexible fiber-optic laryngoscopy. A distribution of interindividual differences demonstrated that GlideScope video laryngoscopy was, on average, 39 seconds faster than flexible fiber-optic laryngoscopy (95% confidence interval 0.2 to 76.9 seconds).

GlideScope video laryngoscopy can be used to obtain a Cormack-Lehane grade II or better view in the majority of awake, healthy volunteers when an upright face-to-face approach is used and was slightly faster than traditional flexible fiber-optic laryngoscopy. However, flexible fiber-optic laryngoscopy may be more reliable at obtaining high-grade views of the larynx. Awake, face-to-face GlideScope use may offer an alternative approach to the difficulty airway, particularly among providers uncomfortable with flexible fiber-optic laryngoscopy.