title: Head position angles to open the upper airway differ less with the head positioned on a support.
abstract: BACKGROUND
  The aim of the study was to assess the effects of positioning the head on a support on "head position angles" to optimally open the upper airway during bag-valve mask ventilation.
  
  
  METHODS
  We ventilated the lungs of anesthetized adults with a bag-valve mask and the head positioned with (n = 30) or without a support (n = 30). In both groups, head position angles and ventilation parameters were measured with the head positioned in (1) neutral position, (2) in a position deemed optimal for ventilation by the investigator, and (3) in maximal extension.
  
  
  RESULTS
  Between groups ("head with/without a support") and between head positions within each group, head position angles and ventilation parameters differed (P < .0001, respectively). However, head position angles and ventilation parameters between head positions differed less "with a support" (P < .001), and ventilation parameters improved with a support compared with the head-without-a-support group (P < .001).
  
  
  CONCLUSIONS
  In the head-with-a-support group, when compared with the head-without-a-support group, head position angles differed less, indicating a decreased potential for failure during bag-valve mask ventilation with the head on a support. Moreover, in the head-with-a-support group, ventilation parameters differed less between head positions, and ventilation improved. These findings suggest a potential benefit of positioning the head on a support during bag-valve mask ventilation.
authors.affiliation: Department of Anaesthesiology and Critical Care Medicine, Innsbruck Medical University, Anichstrasse 35, 6020 Innsbruck, Austria. Thomas.Mitterlechner@uki.at
authors.forename: Thomas
authors.initials: T
authors.lastname: Mitterlechner
authors.forename: Peter
authors.initials: P
authors.lastname: Paal
authors.forename: Lukas
authors.initials: L
authors.lastname: Kuehnelt-Leddhin
authors.forename: Alexander M
authors.initials: AM
authors.lastname: Strasak
authors.forename: Günther
authors.initials: G
authors.lastname: Putz
authors.forename: Nikolaus
authors.initials: N
authors.lastname: Gravenstein
authors.forename: Achim
authors.initials: A
authors.lastname: von Goedecke
authors.forename: Volker
authors.initials: V
authors.lastname: Wenzel
mesh_terms: D000328:Adult; D000403:Airway Resistance; D000704:Analysis of Variance; D000758:Anesthesia / Q000379:methods; D018592:Cross-Over Studies; D005260:Female; D006257:Head; D006801:Humans; D017214:Laryngeal Masks; D008297:Male; D056888:Patient Positioning; D011446:Prospective Studies; D012121:Respiration, Artificial / Q000295:instrumentation*