Ventilation efficacy of video-laryngoscopes equipped with a ventilation feature

Achieving effective ventilation is challenging for anesthesia care providers and emergency medical personnel, as difficult mask ventilation and difficult intubation frequently occur. The aim of this study was to determine whether video-laryngoscopes equipped with a ventilation feature can produce effective ventilation.

An intubation mannequin with its trachea connected to a model lung with compliance 50 (normal compliance: C50) and 20 mL/cm H2O (low compliance: C20) was used. Ventilation was established via a ventilation catheter (inner diameter 3.5 mm, 50 cm length) extending to the tip of the video-laryngoscope blade. Three different views of the vocal cords (grade 1, vocal cords fully visualized; grade 2, partial vocal cord visualization; grade 3, only epiglottis visualized) were tested. Ventilation was provided by jet ventilator (Jet). The Jet was operated at 10, 15, and 20 psi (Jet10, Jet15, and Jet20). Effective tidal volume (V(T)) was defined as a V(T) greater than anatomical dead space (150 mL).

In C50, Jet15 and Jet20 generated effective V(T) in all vocal cord views (for Jet15: grade 1, 663 ± 33 mL; grade 2, 363 ± 25 mL; and grade 3, 198 ± 9 mL; for Jet20: grade 1, 1,005 ± 114 mL; grade 2, 484 ± 38 mL; grade 3, 268 ± 8 mL, respectively). In C20, Jet15 and Jet20 generated effective V(T) in grades 1 and 2 (Jet15: grade 1, 288 ± 8 mL; grade 2, 160 ± 20 mL; grade 3, 81 ± 7 mL; Jet20: grade 1, 421 ± 20 mL; grade 2, 222 ± 16 mL; grade 3, 111 ± 8 mL, respectively). Jet10 achieved effective V(T) in grade 1 and 2 (grade 1, 354 ± 6 mL; grade 2, 223 ± 37 mL, respectively) in C50 and grade 1 (163 ± 12 mL) in C20.

Video-laryngoscopes equipped with a ventilation feature provided effective V(T) in simulated clinical scenarios. Further clinical study is required to validate these findings.