Objective To explore the correlation of patient-controlled sedation of dexmedetomidine and Narcotrend values. Methods Forty patients with lower limb surgery were enrolled. Until CSEA block fixed , the electronic pump ran the patient-controlled sedation of dexmedetomidine. The parameter of electronic pump was set as follows: load dose 2 mL + background dose 1.5 mL/h + single dose 0.5 mL + locktime 20 s. The heart rate , mean arterial pressure, pressing times, effective times, OAA/S sedation scores and NI values were determined. Results At T4 point, the patients reached appropriate sedation. At T4 ~ T9 OAA/S scores kept 3 to 4. From T5 point, NI values showed significant decrease. After the T7 point. OAA/S scores and NI values reached the plateau time of (7.5 ± 1.8) min and (13.1 ± 3.4) min, OAA/S scores of 1, 2, 3, 4, respectively, corresponding roughly with NI values 95 to 100, 90 to 94, 65 to 89, 40 to 64. The correlation coefficient was 0.58. The time of NI values significant decreased in the younger group and in the elderly group, with (10.2 ± 1.6) min and (14.4 ± 2.2) min. In T5~ T9 point, NI values of the younger group were significantly lower than those in the elderly group. Conclusion Relevant relationships are observed between dexmedetomidine patient-controlled sedation depth and the narcotrend values under CSEA.

Objective To deter mine the effect-site concentration of sufentanil blunting responses to tracheal intubation with video laryngoscope during propofol target controlled infusion (TCI). Methods Twenty-three patients undergoing selective surgery under general anesthesia were enrolled in this study. Induction of anesthesia was initiated by TCI sufentanil at the target effect-site concentration 3 min later , TCI of propofol began at the target plasma concentration of 3 μg/mL. Cisatracurium 0.15 mg/kg was ad ministrated for video laryngoscope tracheal intubation after loss of consciousness. The target concentration of sufentanil for consecutive patients was deter mined using the modified Dixon′s up-and-down method by the intubation response of the previous patient , in an increment or decrement of 0.05 ng/mL. The initial concentration was set at 0.4 ng/mL. Results The EC50 of Sufentanil was 0.32 ng/mL with 95%confidence interval of 0.29~0.35 ng/mL; the EC95 was 0.38 ng/mL with 95%confidence interval 0.35-0.55 ng/mL during video laryngoscope tracheal intubation. Conclusion The EC50 and EC95of sufentanil blunting responses to tracheal intubation with video laryngoscope are 0.32 ng/mL and 0.38 ng/mL during propofol TCI.