162 Gut and Liver, Vol. 5, No. 2, June 2011 Table 1. Baseline Characteristics of Patients in the BIS and Non-BIS Groups Table 3. Sedative Drug Doses and Satisfaction Scores of the Two Groups Non-BIS group p-value (n=24) Mean age Male:Female Mean BMI, kg/m2 Concurrent narcotic or anxiolytic medication use Alcohol Smoking ASA classification 1 2 No. of lesions Tumors Adenoma Cancer Location Lower Middle Upper Resected tumor size, mm Size of lesion, mm Procedure time, min Curative resection BIS group (n=26) 60.8±10.0 19:7 23.7±2.7 6 (23) 12 (46.2) 6 (23) 17 (65.4) 9 (34.6) 29 7 (24.1) 22 (75.9) 18 (62.1) 8 (27.6) 3 (10.3) 40.3±13.6 17.6±11.9 58.1±29.2 26 (89.7) Data are presented as mean±SD or number (%). BIS, bispectral index monitoring; BMI, body mass index; ASA, Amer- ican Society of Anesthesiologists. Table 2. Endoscopic and Pathological Characteristics of the Two Groups BIS group Non-BIS group p-value Data are presented as mean±SD or number (%). BIS, bispectral index monitoring; NS, not significant. 2. Dose of sedative drug and satisfaction score The dose of midazolam used in the BIS group was larger than in non-BIS group (p=0.01). The mean dose of midazolam and meperidine used in BIS group was 6.8±2.0 mg and 62.5±27.6 mg, respectively. That used in non-BIS group was 5.4±2.1 mg and 51.0±17.3 mg, respectively. There was no significant difference between the two groups with regard to recall of pain during the procedure and satisfac- tion with sedation (Table 3). Table 4 showed hemodynamic parameters, BIS monitoring, and complications. There was no blood pressure drop below 90 mmHg during the sedation. The mean BIS score in BIS group was lower than in non-BIS group (p<0.01). Hypoxemia (SpO2 <90%) was detected in both groups (8 58.3±9.6 20:4 24.4±2.9 2 (8.3) 5 (20.8) 7 (29.2) 17 (79.8) 7 (29.2) 25 11 (44) 14 (56.0) 14 (56) 9 (36) 2 (8) 40.9±16.1 11.6±7.6 47.0±23.5 22 (88) 0.384 0.501 0.696 0.250 0.078 0.623 0.679 0.123 0.838 0.875 0.03 0.128 NS Sedation drug Mean dose of midazolam, mg Mean dose of meperidine, mg Satisfaction score Recall of procedure Pain Patients Endoscopist 62.5±27.6 51.0±17.3 BIS group (n=26) 6.8±2.0 13.5±28.0 12.7±27.4 92.3±16.3 83.1±15.4 Non-BIS group (n=24) 5.4±2.1 22.5±35.7 15.8±30.4 93.3±15.5 80.0±16.7 p-value 0.01 0.18 0.47 0.97 0.53 0.52 Data are presented as mean±SD. Recall scores, pain scores, and satisfaction scores range from 0 to 100 (lowest score, 0; highest score, 100). BIS, bispectral index monitoring. Table 4. Hemodynamic, BIS, and Complications Mean BP, mm Hg Mean heart rate Mean BIS SpO2 <90% Electrocautery Perforation BIS group (n=26) 120.9±16.16 69.27±14.21 77.0±2.69 8 (30.1) 1 (3.8) 1 (3.8) Non-BIS group (n=24) 119.21±13.46 70.46±12.64 80.3±4.84 6 (25) 1 (4.2) 0 p-value 0.693 0.756 <0.01 0.649 NS NS Data are presented as mean±SD or number (%). Mean BP=(2*systolic BP+ diastolic BP)/3. BIS, bispectral index monitoring; BP, blood pressure; NS, not signifi- cant. patients in BIS group and 6 patients in non-BIS group), which recovered soon after oxygen was provided. The delayed bleed- ing and perforation rate did not showed significant difference in two scoring system. We additionally investigated that the correlation of BIS levels and MOAA/S scores during ESD procedure because there was no data of correlation between two scoring systems in ESD procedure. The mean scores of BIS and MOAA/S was 80.1±5.9 (range, 66 to 98) and 2.8±0.7 (range, 1 to 4), respectively. Two scoring systems showed weak correlation in ESD procedure with midazolam and meperidine induced sedation (correlation coef- ficient=0.274, p<0.001). DISCUSSION Several sedative drugs and a variety of combinations such as propofol with or without a benzodiazepine or opioid, benzodi- azepine plus an opioid, a benzodiazepine alone, entonox, and others, are used for sedation during endoscopic procedures.21