Bispectral Index Monitoring and Observer Rating Scale Correlate with Dreaming during Propofol Anesthesia for Gastrointestinal Endoscopies

Abstract

Background and objectives: Dreaming is a commonly reported side effect of propofol anesthesia. Materials and Methods: We investigated the inci-dence and character of dreams in patients undergoing intravenous propofol anesthesia and cor-related it with an observer rating scale of facial expression on the seven-point scale from pain to smile. A total of 124 patients undergoing gastrointestinal endoscopy were recruited in the pro-spective observational study. Bispectral index (BIS), blood pressure (BP), and pulse were moni-tored. Upon emergence from anesthesia, the patient’s facial expression was rated numerically. Thereafter, patients were asked whether they had dreams and to rate their dreams as pleasant or unpleasant. The mean age of participants was 53; body mass index, 26.17; duration of procedure, 20 min; and average propofol dose, 265 mg. Results: Dreaming was reported by 43% of patients. Dreams were pleasant in all but one patient. There was a significant correlation of the observer’s rating of facial expression with dreaming (r = 0.260; p = 0.004). Dreamers had higher scores of observer rating of facial expression (1 (0–2) vs. 0.5 (0–1), p = 0.006). Conclusions: BIS values were lower in the dreamers vs. non-dreamers 2 min after the endoscopy started (48 (43–62) vs. 59 (45–71), p = 0.038). Both BIS and observer ratings correlate with dreaming in patients undergoing gastrointestinal endos-copy. Trial registration number: NCT04235894.

Keywords

• propofol
• anesthesia
• general
• endoscopy
• gastrointestinal
• dreams