Comparative Effects of Dexmedetomidine and Midazolam on Dreaming of Patients Undergoing Flexible Bronchoscopy During General Anesthesia

Background: The aim of this study was to compare the effects of dexmedetomidine versus midazolam on the dreaming of patients undergoing flexible bronchoscopy during general anesthesia. Methods: Patients undergoing flexible bronchoscopy under general anesthesia were randomly divided into a dexmedetomidine group (Group D, n=40) and a midazolam group (Group M, n=40). In group D, patients received 0.5 mu g/kg dexmedetomidine and in group M patients received 0.05 mg/kg midazolam intravenously 10 min prior to induction. After bronchoscopy and recovery, a modified Brice questionnaire was used to immediately evaluate the incidence of dreaming of patients. Dreamers were required to complete a 5-point Likert scale survey regarding the contents of their dreams (emotion, voice and movement, memorability) if dreaming was reported. Ramsay Sedation Scale score (Ramsay score) and Visual Analogue Scale (VAS) score were assessed and recorded. Results: Patients in group D had higher Ramsay scores and VAS scores (2.9 +/- 0.6 and 79.4 +/- 4.0, respectively) than group M (2.4 +/- 0.7 and 75.0 +/- 6.0, respectively), with a statistically significant difference (P<0.05) between groups. The incidence and memorability of dreaming were significantly lower in group D (17.5%) than group M (37.5%, P<0.05), whereas no significant difference was found in emotion, voice, and movement scores of dreaming. Conclusions: Compared to midazolam, pre-injection of dexmedetomidine before induction significantly decreased the incidence of dreaming in patients undergoing flexible bronchoscopy during general anesthesia, without producing undesirable effects on the content of dreams (most of them were pleasant), produces a more efficacious sedation effect during the recovery period and improves the comfort level and satisfaction of patients.