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

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.

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.

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).

Laryngeal visualization using the Pentax-AWS with the new thinner Introck-T produces the anterior movement and extension of the cervical spine.