老年患者麻醉趋势指数和脑状态指数与靶控输注丙泊酚预测效应室浓度的相关性

-Correlation between the Narcotrend index, the cerebral state index and the predicted effect site concentration during different state of consciousness in elderly patients with target controlled infusion of propofol

目的探讨在无手术刺激状态下老年患者靶控输注丙泊酚时麻醉趋势指数（NCT）、脑状态指数（CSI）与不同镇静程度时预测效应部位浓度的相关性。方法选择ASAⅠ～Ⅱ级，年龄65～75岁，行择期普外科手术患者20例。诱导插管前以丙泊酚靶控输注镇静，丙泊酚预测效应部位靶浓度从0．5mg／L开始递增，递增梯度为0．5mg／L，每一靶浓度输注5min，直至改良清醒镇静评分（OAA／S）为0后5min停止，连续监测患者Narcotrend指数和脑状态指数变化。每间隔20s行改良OAA／S评分，记录靶控输注系统预测效应部位浓度值每变化0．1mg／L时的预测效应部位浓度数值及时间及患者在丧失语言反应及意识消失时的预测效应部位浓度、NCT和CSI值。结果丙泊酚预测效应部位浓度值与NCT和CSI均呈较好的线性关系（砰分别为0．867与0．893，P〈0．01）。患者出现语言反应消失时的异丙酚预测效应部位浓度为（1．56±0．13）mg／L，NCT值为74．00±4．69，CSI值为69．82±5．47。患者出现意识消失时的预测效应部位浓度值（2．15±0．27）mg／L，NCT为63．30±7．50，CSI值为58．78±6．90。预测效应部位浓度值、NCT值、CSI值与OAA／S评分相关性良好，相关系数分别为-0．968、0．938、0．940（P〈0．01），OAA／S评分与Ce负相关，与NCT和CSI正相关。不同意识状态下NCT和CSI值相比，NCT值偏高（P〈0．01）。结论老年患者靶控输注丙泊酚后出现语言反应消失及意识消失时预测效应部位浓度值波动在一定的范围；NCT、CSI和丙泊酚预测效应部位浓度呈线性相关；NCT和CSI的监测均能反映老年患者丙泊酚的镇静程度；NCT与CSI指数显著相关，但在一定范同内要注意其存在偏差。

Objective To study the correlation between the Narcotrend index, cerebral state index and predicted effect site concentration during different state of consciousness in the absence of surgery in elderly patients with target controlled infusion of propofol. Methods Twenty patients aged from 65-75 years categorized as ASA class Ⅰ - Ⅱ who were scheduled to undergo general surgery under general anesthesia with target controlled infusion of propofol were recruited. During the target controlled infusion of propofol, the propofol infusion was set at an initial effect site concentration of 0.5 mg/L and increased by 0.5 mg/L every 5 rain until the modified observer＇s assessment of alertness / sedation scale （OAA/S） values of zero. The predicted effect site concentration of propofol, the values of CSI and NCT were recorded and the sedation level was examined by the modified OAA/S every 20 s. The predicted effect site concentrations of propofol in target controlled infusion （TCI） system were recorded when they increased by more than 0. 1 mg/L. The predicted effect site concentrations of propofol and the values of NCT and CSI at LVC and LOC of the patients were recorded. Results There was a good linear correlation between NCT and the predicted effect site concentration of propofol （R2 = 0. 867, P 〈 0.01 ） , as well as that between CSI and the predicted effect site concentration of propofol （ R2 = 0. 893, P 〈 0.01 ） . The predicted effect site concentrations of propofol at LVC was （ 1.56 ± 0.13 ）mg/L while the values of NCT was 74.00 ± 4.69 and CSI 69.82 ± 5.47. The predicted effect site concentrations of propofol at LOC was （2.15 ± 0.27 ） mg/L while the values of NCT and CSI were 63.30 ±7.50 and 58.78 ± 6.90 respectively. All of the values of NCT, CSI and the predicted effect site concentrations had a good linear correlation with OAA/S. There was a negative correlation between OAA/S and the predicted effect site concentration. At the same time, there was a positive correlation between OAA/S and NCT as well as that between OAA/S and CSI. And the correlation coefficients were - 0. 968, 0. 938, 0. 940 respectively （P 〈 0.01 ）. The values of NCT were higher significantly than that of CSI in different degree of LOC （ P 〈 0.01 ）. Conclusion During elder people＇s target controlled infusion of propofol, LVC and LOC occur within a definite range of predicted effect site concentrations. There is a good linear correlation between NCT, CSI and the predicted effect site concentrations of propofol. For the elders, both NCT and CSI reflect the sedation level of propofol. Although there is a significant correlation between NCT and CSI, a deviation does exist in a certain range. Therefore a simple 1：1 transfer from NCT to CSI is inadequate.