近日节律对靶控输注依托咪酯镇静效应的影响

Effects of circadian rhythm on sedative effect of etomidate by target controlled infusion

目的 通过上午、下午靶控输注（TCI）依托咪酯麻醉诱导时依托咪酯血浆靶浓度测定,探讨近日节律对TCI依托咪酯镇静效应的影响.方法 选择术前未用药患者60例,ASA Ⅰ或Ⅱ级,随机分为上午组（8：00～10.00,A组,30例）和下午组（14：00～16：00,P组,30例）TCI依托咪酯进行全麻诱导.以血浆靶浓度150 ng/ml为起点,达到预期的血浆靶浓度5 min后,每次增加50ng/ml,直到患者意识消失（睫毛反射消失及OAA/S评分≤3分,且BIS≤50）.记录BIS为50和意识消失时的依托咪酯血浆靶浓度.结果 BIS达50和意识消失时,两组患者HR、MAP、SpO2、BIS差异均无统计学意义.与P组比较,BIS达50和意识消失时,A组依托咪酯血浆靶浓度明显升高（P＜0.05）.结论 近日节律对依托咪酯的镇静作用有影响,下午组TCI依托咪酯患者BIS达50和意识消失时所需血浆靶控浓度较低.

Objective To explore the effects of circadian rhythm on the sedative effects of etomidate through the target plasma concentrations of etomidate by using target controlled infusion （TCI） under anesthesia induction in the morning or in the afternoon.Methods Sixty ASA Ⅰ or Ⅱ patients under general anesthesia without premedication were equally randomized into two groups,morning group （8：00-10：00,group A） and afternoon group （14：00-16：00,group P）.General anesthesia induction was performed by TCI of etomidate.The target plasma concentration of etomidate started at 150 ng/ml and maintained for 5 min,and then increased 50 ng/ml each time until the patients lost consciousness （loss of eyelash reflex,OAA/S≤3 and BIS value≤50）.The target plasma concentration of etomidate,HR,MAP,SpO2 and BIS values were recorded when the BIS value reached 50 and the patients lost consciousness.Results There was no difference in HR,MAP,SpO2,BIS value in the two groups when BIS reached 50 and patients lost consciousness.Compared with group P,the target controlled concentrations of etomidate significantly increased in group A when BIS reached 50 and patients lost consciousness （P 〈 0.05）.Conclusion Circadian rhythm can affect the sedative effect of etomidate and the target plasma concentration of etomidate are lower in the afternoon than in the morning when BIS reached 50 and patients lost consciousness.