Comparative in-vitro Study of the Trachospray, a New Device for Topical Anaesthesia of the Upper Airway.

Background: Obtaining complete topical anaesthesia of the airway remains a clinical challenge. Particle size is one of the most important variables for the dose deposited and the distribution of aerosols in the airways. The mass median aerodynamic diameter of the particles should be in the range of 5-20 µm.