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

BACKGROUND: 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.

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

METHODS: 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).

RESULTS: 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.

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