硬膜外阻滞期间反馈靶控输注异丙酚清醒镇静的临床研究

Clinical study of propofol sedation by feedback target controlled infusion during epidural block

目的评价脑电双频谱指数(BIS)作为反馈靶控输注异丙酚在硬膜外阻滞期间清醒镇静的可行性。方法将50例在硬膜外阻滞下完成择期手术的病人,随机分为靶控输注组(TCI组),反馈靶控输注组(FTCI组),每组25例。以1.0μg/kg为初始靶控浓度开始输注,在效应室异丙酚浓度达到平衡后3min,将靶控浓度增加至1.8μg/ml。TCI组整个手术过程中维持此浓度不变。FTCI组5min后开启BIS反馈系统,当BIS>75时,持续进行TCI,BIS<75停止TCI。整个调控由脑电监测仪器控制输注泵自动完成。记录两组病人麻醉前(T1)、开启BIS反馈系统前(T2)、切皮时(T3)、腹腔探查时(T4)、手术60min时(T5)、术毕停异丙酚输注时(T6)、病人清醒时(T7)等各时点BIS、MAP、HR、SPO2的参数及OAA/S评分,并记录两组病人麻醉时间、异丙酚总用量、平均给药速度、意识恢复时间,计算术中OAA/S、BIS、MAP、评分的最大值和最小值之差,分别表示为△OAA/S、△BIS、△MAP。随访有否术中知晓。结果与T1比较,两组患者在T2时BIS、MAP、HR均下降(P<0.05),T4时MAP、HR升高(P<0.05)。与FTCI组比较,TCI组患者在T4时BIS、MAP、HR升高,而在T6时上述几项指标均下降(P<0.05),术中△OAA/S、△BIS、△MAP升高(P<0.05)。FTCI组病人异丙酚总用量犤(410±33)mg犦显著低于TCI组犤(528±59)mg犦(P<0.01)。结论应用BIS值反馈靶控输注异丙酚在硬膜外阻滞期间的清醒镇静,可更加合理地评估镇静的深度,防止术中知晓,减少异丙酚用量,加快病人清醒,安全有效,较TCI更适用于临床。

Objective To study the feasibility of sedation with propofol by feedback target controlled infusion(FTCI) during epidural block. Methods Fifty patients with epidural block were randomly divided into two groups:FTCI group and target controlled infusion(TCI) group(n=25 in every group). For all patients in two groups, the target concentration of propofol was set at 1.0μg/kg at the beginning. When concentration of propofol reached the equilibrium point for 3 minutes that was increased to 1.8μg/ml. The value was kept throughout anesthesia for patients in TCI group. In FTCI group, sedation was controlled by FTCI according to changes of bispectral index(BIS). If BIS was more than 75 TCI was activated. In two groups parameters BIS, MAP, HR, SPO2 and OAA/S grades were respectively recorded before anesthesia(T1),before FTCI(T2),cutting skin(T3), exploration(T4),for 60 minutes after operation(T5),the end of operation(T6) and regain consciousness(T7). The differences between the maximum and the minimum of OAA/S, BIS and MAP grades were calculated respectively(They are named as △OAA/S,△BIS and △MAP correspondingly). Results In two groups, BIS,MAP and HR at T2 were lower than those at T1(P<0.05). MAP and HR at T4 were higher than those at T1(P<0.05). At T4 BIS,MAP and HR in TCI group were obviously increased than those in FTCI group. But at T6 the above values in TCI group were significantly decreased than those in FTCI group (P<0.05).During operation △OAA/S? △BIS and △MAP were also increased obviously(P<0.05). The total dose of propofol(410±33mg)in FTCI group were obviously lower than that(528±59mg) in TCI group, There was significant difference between the two groups(P<0.01). Conclusions By BIS used as a feedback variable of FTCI, better sedation can be achieved in epidural anesthesia with propofol. Depth of sedation can be accurately controlled and evaluated during operation. This method has the advantages of less propofol, rapid emergence and more stable blood pressure.