Relationship between maintaining concentration and loss of consciousness concentration of propofol target controlled infusion in patients undergoing heart valve replacement / 临床麻醉学杂志

ABSTRACT

Objective To investigate the relationship between maintaining concentration and loss of consciousness (LOC) concentration of propofol target controlled infusion (TCI) in patients undergoing heart valve replacement.Methods Thirty patients undergoing elective heart valve replacement were enrolled to receive propofol by ladder plasma TCI for anesthesia induction,8 males and 22 females.The initial plasma concentration (Cp) of propofol was set to 1.0 μg/ml,0.3 μg/ml Cp was increased every 1 min until LOC when the prediction effect-cite concentration (Ce) reached 0.5 μg/ml,then sufentanil 0.8-1.0 μg/kg and rocuronium 0.6-0.9 mg/kg were given for intubation.When BIS reached 50,Cp was decreased to the level of Ce.All the surgeries were performed under hypothermia CPB.MAP,HR,CVP,CO,SV,SVR,BIS,propofol Cp and Ce values were recorded at baseline (T0),LOC (T1),BIS reached 50 (T2),and other time points during operation (T3-T9).The correlation analysis between propofol Ce at LOC and perioperative variables were completed.Results In correlation analysis,there was a significant positive correlation between propofol Ce at LOC and baseline CO,SV (P<0.01),there was a significant negative correlation between propofol Ce at LOC and age (P<0.05),there was a significant positive correlation between propofol Ce at LOC and propofol Ce at T2-T9(P<0.01).Conclusion In patients undergoing valvular replacement,the Ce of propofol at maintenance are related to the concentration of propofol at LOC,which is helpful for adjusting the Ce of propofol at maintenance according to the Ce of propofol at LOC.