title: [Cervical spine movement during bag-mask ventilation].
abstract: BACKGROUND
  Every airway maneuver will cause some degree of neck movement. Ventilation via face-mask technique requires lifting the mandible (jaw thrust) to the facemask. A significant degree of cervical spine motion induced by bag-mask ventilation has been reported on human cadavers with destabilized cervical vertebrae. However, to our knowledge, no quantitative data have reported evaluating the effects of bag-mask ventilation on cervical spine motion in living humans. We measured the cervical spine movement during bag-mask ventilation.
  
  
  METHODS
  Twenty patients requiring general anesthesia were studied. Each patient underwent bag-mask ventilation. Movements of cervical spine were measured by radiography in the same patient both at neutral head position and during bag-mask ventilation.
  
  
  RESULTS
  The anterior movements of the vertebral bodies from baseline were 11.3 +/- 5.8 mm, 11.1 +/- 4.9 mm, 11.0 +/- 4.7 mm and 10.6 +/- 4.4 mm at the atlas, C2, C3, and C4 vertebrae, respectively, during bag-mask ventilation. The changes in angle during bag-mask ventilation were 7.4 +/- 4.5 degrees, 4.9 +/- 4.2 degrees, 1.7 +/- 3.2 degrees, and -0.1 +/- 2.3 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 13.8 +/- 6.4 degrees (95% CI 10.9 degrees-16.8 degrees).
  
  
  CONCLUSIONS
  The lifting the mandible causes both extension and anterior disposition in the cervical vertebrae.
authors.affiliation: Department of Anesthesiology, International University of Health and Welfare Hospital, Nasushiobara 329-2763.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Hirabayashi
authors.forename: Akifumi
authors.initials: A
authors.lastname: Fujita
authors.forename: Hideharu
authors.initials: H
authors.lastname: Sugimoto
mesh_terms: D000328:Adult; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging / Q000502:physiology*; D005260:Female; D006801:Humans; D008397:Masks; D009068:Movement / Q000502:physiology*; D011859:Radiography