Stylet angulation for routine endotracheal intubation with McGrath videolaryngoscope

BACKGROUND: The McGrath videolaryngoscope (VL) provides excellent laryngoscopic views, but directing an endotracheal tube can be difficult, and thus the routine use of a stylet is recommended. The goal of this study is to determine the appropriate angle (60° vs 90°) of the stylet when using the McGrath VL by comparing the time to intubation (TTI). METHODS: One hundred and forty patients aged 19 to 70 years (American Society of Anesthesiologists classification I or II) who required tracheal intubation for elective surgery were randomly allocated to 1 of 2 groups, at the 60° angle (n = 70) or the 90° angle (n = 70). Anesthesia was induced with propofol, fentanyl, and rocuronium. The primary outcome was TTI assessed by a blind observer. Glottic grade, use of optimal external laryngeal manipulation, failed intubation at first attempt, ease of intubation, and severity of oropharyngeal bleeding were also recorded. RESULTS: The mean TTI was significantly shorter in the 60° group than in the 90° group (29.3 ± 6.4 vs 32.5 ± 9.4 s, P = 0.022). The glottic grade and degree of intubation difficulty were not significantly different between the 2 groups. CONCLUSIONS: When intubating the patients with the McGrath videolaryngoscope, the 60° angled stylet allowed for faster orotracheal intubation than did the 90° angled stylet.