title: 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.
authors.affiliation: Department of Anesthesiology, Saitama International Medical Center, Saitama Medical University, 1397-1 Yamane, Hidaka, Saitama 350-1241, Japan. kmaruyam@saitama-med.ac.jp
authors.forename: K
authors.initials: K
authors.lastname: Maruyama
authors.forename: T
authors.initials: T
authors.lastname: Yamada
authors.forename: R
authors.initials: R
authors.lastname: Kawakami
authors.forename: K
authors.initials: K
authors.lastname: Hara
mesh_terms: D000328:Adult; D000368:Aged; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging / Q000502:physiology*; D018592:Cross-Over Studies; D004867:Equipment Design; D005260:Female; D005336:Fiber Optic Technology; D005471:Fluoroscopy / Q000379:methods; D019416:Head Movements; D006801:Humans; D007442:Intubation, Intratracheal / Q000295:instrumentation / Q000379:methods; D020704:Laryngoscopes; D007828:Laryngoscopy / Q000379:methods; D008297:Male; D008875:Middle Aged; D009068:Movement; D014741:Video Recording