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

Background: Topical pharyngeal anesthesia is generally used as a pretreatme nt for upper endoscopy. However its efficacy has not been established. Methods: 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 pha ryngeal anesthesia, anxiety, and other potential confounding factors by usi ng logistic regression analyses. Results: The RR of patient discomfort on intubation was 0.56 for the anesth esia versus the placebo group (95% CI, 0.31-1.01). RR was higher in patient s 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 endosco py 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 = 0.2 0; 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, st atistical significance is indicated by a CI of 97.5% in the subgroup analys es. Conclusions: Topical pharyngeal anesthesia appears to be effective in patie nts less than 40 years old and in those undergoing the procedure for the fi rst time. A high trait-anxiety score could be a predictor of discomfort in first-time examinees.