The glidescope video laryngoscope in the hands of novice users: Seeing the larynx does not correlate with intubation success

Abstract

Study objectives: Rescue intubation devices should be easy to use. The Glidescope Video Laryngoscope (GVL) uses a miniature video camera built within a curved laryngoscope. The camera position and wide field of view create laryngeal visualization by a monitor in almost any patient. Because of its traditional laryngoscope shape and method of insertion, the GVL should be easy to use, with fast initial skill acquisition. The objective of this study is to assess the intubation performance of novice users of the GVL. Methods: Sixteen participants (11 emergency physicians, 4 residents, 1 physician's assistant) used the GVL on 3 randomly ordered, nonembalmed cadavers. All were easy laryngoscopies with standard equipment. Participants observed 1 demonstration of the GVL and were told to shape the tube stylet as recommended by the manufacturer. Each attempt was recorded and timed using a digital VCR connected to the GVL monitor. Success was defined as tracheal intubation; failure was defined by the inability to intubate the trachea. Results: Laryngeal view was excellent in all 48 intubation attempts (percentage of glottic opening scores >90%). Overall, 36 (75%) of 48 attempts succeeded, with a mean intubation time of 76 seconds (95% confidence interval [CI] 58 to 94 seconds). Seven of 36 successful intubations occurred in 30 seconds or less. Nine of 16 participants succeeded on 3 of 3 cadavers; 1 failed on 3 of 3. Success by cadaver varied from 15 of 16 to 10 of 16, with mean success times per cadaver from 48 seconds (95% CI 31 to 65 seconds) to 108 seconds (95% CI 73 to 143 seconds). Performance was dependent on the specific cadaver and not related to the order of attempts: first cadaver attempt success rate was 13 of 16 (mean time 86±31 seconds) versus third cadaver success rate of 10 of 16 (mean time 74±38 seconds). Conclusion: In this study, novices obtained excellent laryngeal views with the GVL but tracheal tube placement—through a monitor and procedurally similar to laparoscopic surgery—was awkward, slow, and often unsuccessful. GVL difficulty varied considerably between cadavers. Three attempts did not produce competency in our study.