Objective: The factors related to paradoxical excitement during propofol-induced sedation remain unclear. We aimed to investigate this issue during sedated upper endoscopy. Material and methods: Among the health examinees scheduled for sedated upper endoscopy from June 2017 to December 2017, 421 participated in the study. Endoscopists were blinded to the information about the examinees and evaluated the development of paradoxical reactions. Propofol was exclusively used as the sedative agent via intermittent bolus injection. A multiple logistic regression analysis was performed to investigate the factors associated with paradoxical reactions. Results: The incidence of paradoxical reactions was 16.1%. Anxiety (adjusted odds ratio: 2.76; 95% confidence interval: 1.46 - 5.27; p = .002) and age (odds ratio: 0.92; 95% confidence interval: 0.89 - 0.96; p < .001) were significantly associated with paradoxical reactions. Of the nine items of the anxiety questionnaire, four had independent and significant associations with paradoxical reactions (i.e., excess worry, sleeping problems, somatic symptoms, and health concerns; odds ratios: 2.38, 2.71, 2.27 and 2.39, respectively). Conclusion: Propofol-induced paradoxical reactions tend to occur when an individual has anxiety and is of a young age. Further large population-based studies should be performed to confirm this phenomenon.
Keywords: Paradoxical reactions; anxiety; paradoxical excitement; propofol; sedated endoscopy.