Clinical comparison of two stylet angles for orotracheal intubation with the GlideScope video Laryngoscope

Study Objective: To compare the success of orotracheal intubation in 62 seconds or less using the Glide Scope video laryngoscope (GVL) and a 60 degrees or 90 degrees angled stylet with reverse loading of the endotracheal tube (ETT) Design: Prospective, randomized study Setting: Operating room of a university hospital Patients: 120 ASA physical status I, II, and In adult patients undergoing elective surgery requiring general anesthesia with orotracheal intubation Interventions: 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 or 90 group), intubated the tracheas of all patients with the GVL using either the primary or secondary stylet Measurements: The primary outcome was success of orotracheal mtubation in 62 seconds or less The secondary outcome was actual time to mtubation (TTI) Main Results: The odds ratio (OR) for mtubation 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 mtubated 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