title: Use of the Pentax-AWS in 293 patients with difficult airways.
abstract: BACKGROUND
  Several case reports have shown that the Pentax-AWS (Hoya Corporation, Tokyo, Japan), a new video laryngoscope, is useful in patients with difficult airways.
  
  
  METHODS
  We assessed the effectiveness of the Pentax-AWS in two groups. Group 1 included 270 patients in whom direct laryngoscopy using a Macintosh laryngoscope had been difficult. Group 2 included 23 patients with predicted difficult intubation and difficult mask ventilation without previous use of the Macintosh laryngoscope.
  
  
  RESULTS
  In group 1, the view of the glottis with the Macintosh laryngoscope was Cormack and Lehane grade 2 in 14 patients, grade 3 in 208 patients, and grade 4 in 48 patients. In 256 patients in whom the grade was 3 or 4 with the Macintosh laryngoscope, the view with the Pentax-AWS was either grade 1 or 2 in 255 patients (99.6%; 95% confidence intervals 97.8-100%). Tracheal intubation was successful with the Pentax-AWS in 268 of 270 patients (99.3%; 95% confidence interval 97.4-100%), and it failed (after two attempts) in two patients. In group 2, tracheal intubation was successful in 22 of 23 patients, and it failed in one patient. The reasons for failed intubation using the Pentax-AWS were failure to position the blade toward the glottic side of the epiglottis, inability to maneuver the endotracheal tube away from the arytenoids and into the trachea, and bleeding and swelling of the oropharynx.
  
  
  CONCLUSIONS
  The success rate of tracheal intubation using the Pentax-AWS was high in patients with difficult laryngoscopy with a Macintosh laryngoscope and in patients with predicted difficult intubation.
authors.affiliation: Department of Anesthesiology, Kansai Medical University, Takii Hospital, Osaka, Japan. asait@takii.kmu.ac.jp
authors.forename: Takashi
authors.initials: T
authors.lastname: Asai
authors.forename: Eugene H
authors.initials: EH
authors.lastname: Liu
authors.forename: Sanae
authors.initials: S
authors.lastname: Matsumoto
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Hirabayashi
authors.forename: Norimasa
authors.initials: N
authors.lastname: Seo
authors.forename: Akihiro
authors.initials: A
authors.lastname: Suzuki
authors.forename: Takashi
authors.initials: T
authors.lastname: Toi
authors.forename: Kazumasa
authors.initials: K
authors.lastname: Yasumoto
authors.forename: Yasuhisa
authors.initials: Y
authors.lastname: Okuda
mesh_terms: D000402:Airway Obstruction / Q000628:therapy*; D004867:Equipment Design; D005260:Female; D006801:Humans; D017214:Laryngeal Masks; D020704:Laryngoscopes; D007828:Laryngoscopy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative; D008991:Monitoring, Physiologic; D012107:Research Design; D016896:Treatment Outcome; D020535:Video-Assisted Surgery / Q000295:instrumentation*