The laryngeal mask airway and the tracheal route for drug administration

We undertook a study to observe if a preformed curved plastic cannula, the Trachojet, could be passed blindly down a laryngeal mask airway into the trachea in 100 anaesthetized patients. Using air aspiration and a fibreoptic scope to confirm placement of the cannula, it passed into the trachea in only 27% of patients. The air aspiration technique used for detecting tracheal cannulation was 100% successful when the cannula was inserted fully. We conclude that it may not be possible to gain access to the trachea with a Trachojet for drug administration if a laryngeal mask airway is used to maintain the patient's airway.