Dental Strain on Maxillary Incisors During Tracheal Intubation With Double-Lumen Tubes and Different Laryngoscopy Techniques - A Blinded Mannequin Study.

OBJECTIVES: To quantify dental forces during double-lumen tube intubations with different laryngoscopy techniques.

DESIGN: Experimental biomechanical mannequin study.

SETTING: Two German university hospitals.

PARTICIPANTS: One hundred four anesthesiologists with varying levels of experience.

INTERVENTIONS: Participants performed a sequence of intubations on a mannequin equipped with hidden forces sensors in the maxillary incisors. Different laryngoscopy techniques were evaluated under normal and difficult airway conditions. Direct laryngoscopy was compared with different videolaryngoscopy techniques: the C-MAC with a Macintosh blade, the GlideScope, and the KingVision with hyperangulated blades.

MEASUREMENTS AND MAIN RESULTS: A total of 624 intubations were evaluated. In normal airway conditions, the median (interquartile range [range]) peak forces were significantly lower when the GlideScope (15.7 (11.3-22.0 [2.1-110.5]) N) was used compared with direct laryngoscopy (21.0 (14.1-28.5[4.7-168.6]) N) (p = 0.007). In difficult airways, resulting forces were reduced using hyperangulated videolaryngoscopes (GlideScope: -13.7 N [p < 0.001]; KingVision: -11.9 N [p < 0.001]) compared with direct laryngoscopy, respectively. The time to intubation was prolonged with the use of the KingVision (25.5 (17.1-41.9[9.2-275.0])s [p < 0.001]) in comparison to direct laryngoscopy (20.8 (15.9-27.4[8.7-198.6]) s). The C-MAC demonstrated the shortest time to intubation.

CONCLUSIONS: Although hyperangulated videolaryngoscopes improve dental strain, clinicians also should consider the time to intubation, which is shortest with nonhyperangulated videoblades, when choosing a laryngoscopy technique on an individual patient basis.