Objectives: The study evaluates whether facial landmarks can be used to estimate an appropriate laryngoscope blade length for oral endotracheal intubation in children. We tested the hypothesis that the laryngoscope blade measuring 10 mm or less distal or proximal to the angle of the mandible (when the flat portion of the blade follows the facial contour from the upper incisor teeth to the angle of the mandible) will demonstrate greater success and ease of oral tracheal intubation.
Methods: We performed an observational study that prospectively evaluated a convenience sample of children 8 years old or younger and who were undergoing direct laryngoscopy for oral endotracheal intubation in the operating room, outpatient surgery center, emergency department, or pediatric intensive care unit of a tertiary referral medical center. Ease and success of oral tracheal intubation were compared with distance measurements from the angle of the mandible to the tip of the laryngoscope blade.
Results: Blade lengths considered too short (blade lengths >10 mm proximal to the angle of the mandible) were more likely to be associated with more than 1 attempt at intubation. Only 57.1% (12/21; 95% confidence interval [CI], 36.5-75.5) of the intubations using the shorter blade were performed on the first attempt as compared with 89.7% (26/29; 95% CI, 73.6-96.4) of the intubations using the recommended length or 85.7% (6/7; 95% CI, 48.7-97.4) of the intubations using blades extending longer than 10 mm past the angle of the mandible.
Conclusions: The distance from the upper incisor teeth to the angle of the jaw seems to be an excellent clinical landmark for laryngoscope blade length selection for pediatric intubations. When the blade (excluding the handle insertion block) is placed at the upper midline incisor teeth and the tip is located within 1 cm proximal or distal to the angle of the mandible, oral tracheal intubations are more consistently accomplished on the first attempt. Our observations suggest that facial landmarks can be used to estimate an appropriate laryngoscope blade length for oral endotracheal intubation in children.