[Cervical spine motion during laryngoscopy with the Pentax-AWS with a new thinner blade (Introck-T)].

BACKGROUND: The Pentax-AWS equipped with a new thinner blade (Introck-T) is an intubation device that provides a non-line-of sight view of the glottis. A non-line-of sight view is expected to cause less movement of the cervical spine during laryngeal visualization. We measured the degree of cervical spine movement during laryngoscopy with the device. METHODS: Twenty patients requiring general anesthesia were studied. Each patient underwent laryngoscopy using the Pentax-AWS with the Introck-T. Movements of cervical spine were measured by radiography in the same patient both at neutral head position and during laryngoscopy. RESULTS: The anterior movement of the vertebral bodies from baseline was 16.7 +/- 5.2 mm, 16.5 +/- 4.4 mm, 16.5 +/- 4.7mm and 15.5 +/- 4.7mm at the atlas (C1), C2, C3, and C4 vertebrae, respectively, during laryngoscopy. The change in angle during laryngeal visualization was 8.3 +/- 4.0 degrees, 7.6 +/- 3.7 degrees, 1.7 +/- 2.4 degrees, and 1.6 +/- 3.3 degrees, at Occiput/C1, C1/C2, C2/C3, and C3/C4 motion segments, respectively. The total change in angle between the occiput and C4 was 19.1 +/- 5.1 degrees (95% CI 16.6 degrees - 21.5 degrees). CONCLUSIONS: Laryngeal visualization using the Pentax-AWS with the new thinner Introck-T produces the anterior movement and extension of the cervical spine.