Randomized cross-over comparison of cervical-spine motion with the AirWay Scope or Macintosh laryngoscope with in-line stabilization: a video-fluoroscopic study

Abstract

Background: The AirWay Scope (AWS) is a fibreoptic device that allows for intubation without alignment of the oral, pharyngeal, and tracheal axes. It may be useful for patients with an unstable cervical-spine (C-spine) or when C-spine movement is undesirable. This study was conducted to fluoroscopically evaluate upper C-spine movement during tracheal intubation with the AWS and or the Macintosh laryngoscope with in-line stabilization (ILS).

Methods: Thirteen patients with a normal C-spine and scheduled for elective surgery agreed to simulation of an unstable C-spine and ILS. Two attempts at laryngoscopy were allowed. Laryngoscopy was performed with the Macintosh laryngoscope, then with the AWS, or vice versa. The movement of the upper C-spine during intubation was examined by measuring the angles formed by adjacent vertebrae from the occiput to C4. Time to achievement of intubation was also recorded.

Results: The AWS significantly decreased median movement of the C-spine at the occiput/C1, C1/C2, and C3/C4 concentrations (P=0.041, 0.0079, and 0.0050, respectively), resulting in a significant decrease in cumulative upper C-spine movement (13.5 degrees with the AWS compared with 30.5 degrees with the Macintosh laryngoscope, P<0.01). Intubation time did not differ [23.8 (SD 16.7) s with the AWS; 17.9 (6.4) s with the Macintosh].

Conclusions: In comparison with the use of the Macintosh laryngoscope, the AWS decreased median upper C-spine movement during intubation under ILS in patients with normal C-spine.