Effect Of Blood Loss Plasma Concentration And AAI Of Target Controlled Infusion Propofol

Target controlled infusion(TCI) is a kind of anesthesia method which based on pharmacokinetic and by the plasma drug concentration or effect compartment for the expected index. The computer control the rate of drug infusion to achieve the expected depth of anesthesia according to the patient’s body weight, height, age, gender and other parameters.The pharmacokinetic data of target controlled infusion of propofol were from abroad and no detailed data of chinese people,so,the different racial causative pharmacokinetics inaccurate. moreover,the individual differences of patients(such as obesity, combined with the department of internal medicine disease) 、 lose blood 、 temperature change and so on,many factors that cause the difference between calculated plasma concentration and measyred plasma concentration,then affect to the depth of anesthesia.The experiment aims to investigate the effect of blood loss on plasma concentration and AAI of propofol target controlled infusion and to provide clinical of intravenous anesthesia using propofol target controlled infusion.One hundred-eight patients(ASA grade I or 11) who were given bone surgery operation in our hospital were randomly divided into three groups: GroupA, blood loss ≤300ml; GroupB, 300ml<blood loss≤600ml; GroupC, blood loss>600ml.Three groups were induced and maintained with TCI of propofol(Shinder model)and remifentanil(Minto model), The default target plasma concentration of propofol(3.5ug · ml-1~4.5ug·ml-1) and remifentanil(4ng·ml-1) during induction detection and monitoring depth of anesthesia with AAI whole range. Given muscle relaxants cisatracurium 0.15mg·kg-1 when AAI down to 30 and tracheal intubation after three minutes,connected to a ventilator intermittent positive pressure ventilation to manintain respiration.Arterial blood samples were taken at anesthetize 5 min(T1)、30min(T2)、60min(T3)、120min(T4)、180min(T5)、240min(T6), and recording the changes of hemodynamics and auditory evoked potential index(AAI) at the same time. The measyred plasma concentration(Cmp)of propofol were compared with the calculated plasma concentration(Ccp)by the median performance error(MDPE), the median absolute performance error(MDAPE)and wobble then to evaluate the performance of TCI systems.In the duration of T4-T6, the blood loss in group C was significantly higher than group and group B(P<0.01), group B higher than group A(P<0.05), and the volume of fluid infusion of group C was significantly higher than group A and group B(P<0.01), group B higher than group A(P<0.05). The MAP of group C was decreased than group A and group B(P<0.05) in the duration of T5-T6. The plasma concentration of T3 and T4 were lower than T1(P < 0.05), T5 and T6 were significant decreased more than T1(P<0.01),group C was lower than group A in the duration of T4-T6(P < 0.05).The depth of anesthesia monitoring of patients in the three groups(AAI) showed no significant difference at each time point between(P > 0.05), each time point comparisons between groups had no significant difference(P > 0.05).The MDPE was 17.74% of group C in T6.The experiment shows that different blood concentration caused by blood loss were lower than target concentration, but due to the loss of blood at the same time, then the distribution of the body of propofol blood drug caused by liquid supply, resulting in obvious fluctuations of depth of anesthesia. Blood loss is less than 600 ml, target controlled pump system deviation in clinical deviation range, but when the blood loss more than 600 ml, the target control system deviation(MDPE) was 17.74%, and the TCI systems(whith Shnider pharmacokinetic parameter) beyond the clinical acceptable range(0~15%), if the blood loss to continue, the target controlled system may overestimate the patient blood concentration and lead to the depth of anesthesia by shallow, but according to AAI monitoring to regulate target propofol concentration can maintain stable vital signs.