title: Clinical comparison of two stylet angles for orotracheal intubation with the GlideScope video laryngoscope.
abstract: OBJECTIVE
  To compare the success of orotracheal intubation in 62 seconds or less using the GlideScope video laryngoscope (GVL) and a 60 degrees or 90 degrees angled stylet with reverse loading of the endotracheal tube (ETT).
  
  
  METHODS
  Prospective, randomized study.
  
  
  METHODS
  Operating room of a university hospital.
  
  
  METHODS
  120 ASA physical status I, II, and III adult patients undergoing elective surgery requiring general anesthesia with orotracheal intubation.
  
  
  METHODS
  Patients were randomly allocated to two groups (n = 60 each); both groups received general anesthesia and neuromuscular relaxation. A conventional ETT was styleted and then bent from its straight configuration just above the cuff, either at 60 degrees or 90 degrees against its concave natural curve (reverse loading). Four attending anesthesiologists, who were blinded as to stylet assignment (the 60 degrees or 90 degrees group), intubated the tracheas of all patients with the GVL using either the primary or secondary stylet.
  
  
  METHODS
  The primary outcome was success of orotracheal intubation in 62 seconds or less. The secondary outcome was actual time to intubation (TTI).
  
  
  RESULTS
  The odds ratio (OR) for intubation success was higher in the 90 degrees group than the 60 degrees group (OR = 10.41; P < 0.03), as evidenced by 59 of 60 patients whose tracheas were intubated successfully within 62 seconds, compared with 51 of 60 patients in the 60 degrees group. Seven of the 9 failures were due to inability of the 60 degrees stylet to reach the glottic opening. The three remaining failures were associated with TTI of more than 62 seconds.
  
  
  CONCLUSIONS
  The 90 degrees angled malleable stylet with reverse loading of the ETT provided more reliable ETT delivery to the glottic opening and had a higher success rate than the 60 degrees stylet.
authors.affiliation: Department of Anesthesiology and Department of Biostatistics, University of Rochester School of Medicine & Dentistry, Rochester, NY 14642, USA. mdupanovic@kumc.edu
authors.forename: Mirsad
authors.initials: M
authors.lastname: Dupanović
authors.forename: Sheldon A
authors.initials: SA
authors.lastname: Isaacson
authors.forename: Zana
authors.initials: Z
authors.lastname: Borovcanin
authors.forename: Sushma
authors.initials: S
authors.lastname: Jain
authors.forename: Santiago
authors.initials: S
authors.lastname: Korten
authors.forename: Suzanne
authors.initials: S
authors.lastname: Karan
authors.forename: Susan P
authors.initials: SP
authors.lastname: Messing
mesh_terms: D000328:Adult; D000368:Aged; D000768:Anesthesia, General / Q000379:methods; D017558:Elective Surgical Procedures / Q000379:methods; D004867:Equipment Design; D005260:Female; D006785:Hospitals, University; D006801:Humans; D007442:Intubation, Intratracheal / Q000379:methods*; D020704:Laryngoscopes; D007828:Laryngoscopy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D016037:Single-Blind Method; D013997:Time Factors; D014741:Video Recording