title: Pentax-AWS, a new videolaryngoscope, is more effective than the Macintosh laryngoscope for tracheal intubation in patients with restricted neck movements: a randomized comparative study.
abstract: BACKGROUND
  We studied whether laryngoscopy and tracheal intubation were easier when using the Pentax-AWS (Tokyo, Japan), a new videolaryngoscope, than when applying the Macintosh laryngoscope, during manual in-line neck stabilization.
  
  
  METHODS
  In 203 anaesthetized patients with manual in-line neck stabilization, we inserted the Pentax-AWS and a Macintosh laryngoscope, in turn, and recorded the view of the glottis and time taken to laryngoscopy. The success rate of tracheal intubation (within 120 s) and time to intubation were also recorded.
  
  
  RESULTS
  The view of the glottis was significantly better with the Pentax-AWS than with the Macintosh laryngoscope (P<0.001). For the Macintosh laryngoscope, the view was obscured in 22 of 203 patients (11%) (Grade 3 in 21 patients and Grade 4 in one patient), whereas for the Pentax-AWS, the glottis was always clearly seen (Grade 1). Time taken to see the glottis with the Pentax-AWS [mean (sd): 6.0 (3.1) s] was significantly shorter than with the Macintosh laryngoscope [11.0 (5.0) s] (95% CI for difference: 4-6 s). The success rate of tracheal intubation with the Pentax-AWS (all of 99 patients) was significantly higher than with the Macintosh laryngoscope (93 of 104 patients) (P=0.001). Time taken for intubation was similar between the Macintosh laryngoscope [51 (27) s] and the Pentax-AWS [54 (14) s] (95% CI for difference: -9 to 3 s).
  
  
  CONCLUSIONS
  In patients with stabilized neck, the Pentax-AWS provided a better view of the glottis and a higher success rate of tracheal intubation, compared with the conventional Macintosh laryngoscope.
authors.affiliation: Department of Anaesthesiology, Koshigaya Hospital, Dokkyo Medical University, Koshigaya City, Saitama, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Enomoto
authors.forename: T
authors.initials: T
authors.lastname: Asai
authors.forename: T
authors.initials: T
authors.lastname: Arai
authors.forename: K
authors.initials: K
authors.lastname: Kamishima
authors.forename: Y
authors.initials: Y
authors.lastname: Okuda
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018592:Cross-Over Studies; D004209:Disposable Equipment; D004867:Equipment Design; D005260:Female; D005336:Fiber Optic Technology / Q000295:instrumentation; D019416:Head Movements; D006801:Humans; D007103:Immobilization / Q000379:methods*; D007442:Intubation, Intratracheal / Q000295:instrumentation* / Q000379:methods; D020704:Laryngoscopes; D008297:Male; D008875:Middle Aged; D013997:Time Factors; D016896:Treatment Outcome; D014741:Video Recording