Objective:

Recently, to further enhance the potential in the management of difficult airways, the highly angulated D-Blade was added to the C-MAC system. The purpose of this study was to investigate the laryngoscopic view and intubation parameters using the new C-MAC D-Blade in comparison to the conventional C-MAC video laryngoscope and Macintosh direct laryngoscope in simulated easy and difficult airways.

Methods:

We recruited 26 experienced anaesthesia providers into a randomized trial. Each performed tracheal intubation of a Laerdal SimMan® manikin with each laryngoscope in the following laryngoscopy scenarios: (1) normal airway, (2) cervical spine immobilization, and (3) tongue edema. The intubation times, success rates, number of intubation attempts, laryngoscopic views, and severity of dental compression were recorded.

Results:

In all scenarios, video laryngoscopes provided better laryngeal exposure than the ML and appeared to produce less dental pressure. In the cervical spine immobilization scenario, D-Blade caused less dental pressure and showed better Cormack-Lehane (CL) classes than the other devices (p<0.001). There were no differences between video laryngoscopes in success of tracheal intubation (p>0.05). The CMAC provided the most rapid intubation. The rate of failure was 19% with ML. In the tongue edema scenario, the CMAC provided the most rapid and successful intubation (p<0.001). There were no differences between video laryngoscopes in laryngoscopic views according to CL classification and dental pressure (p>0.05). The rate of failure was 46% with the ML and 7% with the D-Blade.

Conclusion:

The CMAC D-Blade caused less dental pressure than the conventional C-MAC and ML in the cervical immobilization scenario. The conventional CMAC performed better than the D-Blade and ML in the tongue edema scenario. These two video laryngoscopes may complement each other in various difficult airway situations.

Keywords: Difficult laryngoscopy, video laryngoscopy, manikin, equipment