Evaluation of topical pharyngeal anesthesia for upper endoscopy including factors associated with patient tolerance

Topical pharyngeal anesthesia is generally used as a pretreatment for upper endoscopy. However its efficacy has not been established.

A randomized double-blind placebo-controlled study was undertaken. Subjects were 201 patients who underwent upper endoscopy and gave informed consent. Relative risks (RR) of patient discomfort were calculated for pharyngeal anesthesia, anxiety, and other potential confounding factors by using logistic regression analyses.

The RR of patient discomfort on intubation was 0.56 for the anesthesia versus the placebo group (95% CI, 0.31-1.01). RR was higher in patients aged 39 or younger than in those 40 or over (RR = 2.22, 95% CI, 1.04-4.74). With subgroup analysis in those examinees less than 40 years old, the RR of patient discomfort was 0.21 for the topical anesthesia (95% CI, 0.04-0.99) versus the placebo group and 4.93 for patients undergoing upper endoscopy for the first time (95% CI, 1.13-21.60). In the first-time patients, the RR was lower in the topical anesthesia than in the placebo group (RR = 0.20; 95% CI, 0.04-0.93); it was higher in patients with a trait-anxiety score higher by 10 points than in those with a lower score (RR = 3.35, 95% CI, 1.01-11.15). With the Bonferroni correction for multiple testing of data, statistical significance is indicated by a CI of 97.5% in the subgroup analyses.

Topical pharyngeal anesthesia appears to be effective in patients less than 40 years old and in those undergoing the procedure for the first time. A high trait-anxiety score could be a predictor of discomfort in first-time examinees.