Midazolam sedation for upper gastrointestinal endoscopy: comparison between the states of patients in partial and complete amnesia

BACKGROUND/AIMS: The amnesia produced by anesthesia is advantageous for unpleasant procedures like gastroscopy, and midazolam is one of the most commonly used anesthesias for endoscopy. However the proper use of midazolam from the viewpoint of complete amnesia has been discussed very little. METHODOLOGY: One hundred and thirty-three unselected patients about to undergo upper gastrointestinal endoscopy were premedicated with sufficient intravenous midazolam to cause enough sedation so that no response was evoked when calling their name. Pulse, arterial pressure, arterial oxygen saturation and the physical signs of patients were recorded continuously during the procedures. After the study, patients were given 0.25 mg of flumazenil and asked if they could recall the procedures. Those who could recall even part of the procedure were not regarded as achieving complete amnesia. The efficacy of the sedative was judged by the appearance of complete amnesia. RESULTS: From our regression analysis complete amnesia was achieved in 75.9% of the total patients. The differences of the blood pressure fall, pulse rate increase and arterial oxygen saturation fall between the patients with complete and partial amnesia were minute and did not cause serious complications. Regression analysis revealed the most important factors for the complete amnesia to be midazolam dose per body weight and habitual hypnotic use. CONCLUSIONS: There are no obvious disadvantages to producing complete amnesia with midazolam for upper gastrointestinal endoscopy. Habitual hypnotic use along with midazolam dose per body weight is the most influencing factor for that purpose.