Cross-over study of topical anaesthesia with tetracaine solution for transoral rigid laryngoscopy

Transoral rigid laryngoscopy with videostroboscopy is the most practical method to visualise the vocal folds. The optimal topical anaesthesia regimen for transoral rigid laryngoscopy has not yet been established.

To compare patient comfort and compliance with various topical anaesthetics for transoral rigid laryngoscopy.

Each of 10 patients received a random topical administration of either 2 per cent lidocaine gel, 1 per cent tetracaine gel or 1 per cent tetracaine solution, 10 minutes before undergoing rigid laryngoscopy with videostroboscopy. During follow-up laryngoscopies, the agent with the lowest mean visual analogue scale score for discomfort was then used to study the timing of topical anaesthetic application: the agent was given to the patient 5, 10 or 15 minutes before laryngoscopy (with the timing randomly selected).

Compared with lidocaine gel or tetracaine gel, laryngoscopy with topical tetracaine solution was more comfortable. There was a statistically significant difference in discomfort score between the 5 and 10 minute application groups, but not between the 10 and 15 minute groups.

Tetracaine solution, applied topically 10 minutes before transoral rigid laryngoscopy, significantly decreases patient discomfort.