Efficacy of Bispectral Index Monitoring During Balanced Propofol Sedation for Colonoscopy: A Prospective, Randomized Controlled Trial

Abstract

Appropriate use of propofol is necessary, and objective monitoring of sedation with propofol may be helpful. Studies on the efficacy of bispectral index (BIS) monitoring in deep sedation have been conducted, but its efficacy in colonoscopy with moderate sedation is unknown. In this study, the efficacy of BIS monitoring during colonoscopy with moderate level sedation via balanced propofol sedation was investigated. To determine the cut-off value of BIS before the test, an optimal BIS value was determined. Patients who were scheduled to undergo outpatient colonoscopy were prospectively randomized to either a BIS or control group. Finally, a total of 115 patients were selected for this study. The satisfaction level, the complication, and the dosage of the administered propofol were compared. The BIS values and the modified observer's assessment of alertness/sedation scores (MOAA/S) were positively correlated (r = 0.66 and p < 0.001). The optimal cut-off value of BIS for maintaining moderate sedation was 81, and the area under the ROC curve was 0.88 (95 % CI 0.82-0.93), indicating high prediction accuracy. However, there was no difference between the BIS group and the control group in levels of satisfaction of either patients or endoscopists. In addition, there was no difference in the complication and the required dose of propofol between both groups. BIS and clinical sedation scores, MOAA/S scores, showed a high level of correlation. However, no significant efficacy was observed in the BIS group who underwent outpatient colonoscopy.