摘要Objective:To study the anesthesia induction effect and RAAS system activity of low-dose midazolam combined with target-controlled propofol infusion under BIS monitoring. Methods:A total of 40 patients undergoing selective general anesthesia surgery in our hospital between April 2012 and December 2015 were selected and randomly divided into control group (group C) and low-dose midazolam group (group M), plasma concentration EC50 of target-controlled propofol infusion was assessed, and the plasma concentrations of NO, NO2-, NO3-, XOD, PRA, ANG-II and ALD were determined before and after induction.Results:Propofol EC50 of group M was significantly lower than that of group C; before and after anesthesia induction, mean arterial pressure, arterial partial pressure of oxygen, arterial partial pressure of carbon dioxide and central venous pressure of group M were not significantly different from those of group C; after anesthesia induction, NO, NO2-, NO3- and XOD content in plasma of group C were significantly lower than those before anesthesia induction while PRA, ANG-II and ALD concentration were significantly higher than those before anesthesia induction, and NO, NO2-, NO3-, XOD, PRA, ANG-II and ALD content in plasma of group M were not significantly different from those before anesthesia induction; NO, NO2-, NO3-and XOD content in plasma of group M after anesthesia induction were significantly higher than those of group C while PRA, ANG-II and ALD concentration were significantly lower than those of group C. Conclusions:Low-dose midazolam combined with target-controlled propofol infusion under BIS monitoring is with exact anesthetic effect and can reduce the dosage of propofol and inhibit the activation of RAAS system.