title: Cricoid pressure impedes tracheal intubation with the Pentax-AWS Airwayscope®: a prospective randomized trial.
abstract: BACKGROUND
  It is unclear how cricoid pressure affects tracheal intubation with the Pentax-AWS Airwayscope(®) (AWS). We conducted a prospective randomized clinical trial in anaesthetized patients.
  
  
  METHODS
  Sixty patients were allocated to either the cricoid pressure (CP) group (n=30) or the sham group (n=30). We compared the two groups with regard to intubation time, number of attempts required for insertion of the Intlock blade (disposable blade of the AWS) and tracheal intubation, percentage of glottic opening (POGO) score, and subjective difficulty of both laryngoscopy and passage of a tube through the glottis.
  
  
  RESULTS
  Intubation time was significantly longer in the CP group (median 45[IQR40-59] s) than in the sham group (32[28-45] s) (P=0.003, 95% CI for median difference 5-24 s). The number required for insertion of the Intlock blade did not differ between the groups (P=0.08), but the number for tracheal intubation was significantly higher in the CP group (1 attempt in 14 patients, 2 in 7, 3 in 9) than in the sham group (1 attempt in 24 patients, 2 in 6; P=0.002). POGO score did not differ significantly between the groups (P=0.60), nor did the subjective difficulty of laryngoscopy (P=0.06). The visual analogue scale score for passage of a tube through the glottis was significantly higher in the CP group than in the sham group (P<0.001).
  
  
  CONCLUSIONS
  Cricoid pressure impedes tracheal intubation using the AWS, and is associated with longer intubation time, which can be attributed to increased difficulty in the passage of a tube through the glottis.
  
  
  BACKGROUND
  UMIN000018209.
authors.affiliation: Department of Anaesthesiology, Osaka Medical College, Daigaku-machi 2-7, Takatsuki, Osaka 569-8686, Japan ane078@poh.osaka-med.ac.jp.
authors.forename: N
authors.initials: N
authors.lastname: Komasawa
authors.affiliation: Department of Anaesthesiology, Osaka Medical College, Daigaku-machi 2-7, Takatsuki, Osaka 569-8686, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Kido
authors.affiliation: Department of Anaesthesiology, Osaka Medical College, Daigaku-machi 2-7, Takatsuki, Osaka 569-8686, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Miyazaki
authors.affiliation: Department of Anaesthesiology, Osaka Medical College, Daigaku-machi 2-7, Takatsuki, Osaka 569-8686, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Tatsumi
authors.affiliation: Department of Anaesthesiology, Osaka Medical College, Daigaku-machi 2-7, Takatsuki, Osaka 569-8686, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Minami
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003413:Cricoid Cartilage / Q000502:physiology; D004867:Equipment Design; D005260:Female; D005931:Glottis; D006801:Humans; D007442:Intubation, Intratracheal / Q000295:instrumentation*; D020704:Laryngoscopes; D007828:Laryngoscopy; D008297:Male; D008875:Middle Aged; D011312:Pressure; D011446:Prospective Studies; D013997:Time Factors
keywords: airway management; cricoid cartilage; tracheal intubation