Effect of different doses of dexmedetomidine on the median effective concentration of propofol during gastrointestinal endoscopy:a randomized controlled trial.

Dexmedetomidine could be an ideal adjuvant to propofol during gastrointestinal endoscopy because it provides both analgesia and sedation without respiratory depression. This study investigates the effect of different doses of dexmedetomidine on the median effective concentration of propofol during gastrointestinal endoscopy METHODS: 90 adult patients were randomly assigned to Group Control , Group DEX0.5 (0.5 μg/kg dexmedetomidine), or Group DEX1.0 (1.0 μg/kg dexmedetomidine) . Anaesthesia during endoscopy was implemented by plasma target-controlled infusion (TCI) of propofol with different doses of dexmedetomidine. TCI concentration of the first patient for each group was 2.5 μg/ml and the consecutive adjacent concentration gradient was 0.5 μg/mL. EC of propofol by TCI for gastrointestinal endoscopy was determined by using the modified Dixon's up-and-down method. Cardiovascular variables were also measured.