The Feasibility Of The Sedation With Midazolam Administered By Target-controlled Infusion In Surgical Intensive Care Unit Patients On The Feedback Of Bispectral Index

Many drugs were used for sedation and analgesic in surgical intensive care unit patients who are being treated with tracheal intubation and mechanical ventilation. It was good at rehab of the patients. The technique of target - controlled infusion (TCI) is an advanced and generally accepted total intravenous anesthesia method, which is more controllable than other methods by utilizating the new achievements of computer technique and pharmacokinetics. Up to now bispectral index (BIS) is the best sensitive and accurate indicator of accessing conscious state. Our research was to evaluate the performance of the target - controlled infusion ( TCI) system of midazolam for sedation, and to observe the feasibility of the sedation with midazolam administered by target controlled infusion in surgical intensive care unit patients on the feedback of bispectral index.Materials and MethodsI . Clinical Materials Thirty ASA II - IV SICU patients reqiring mechanical ventilation were included in this study. The patients were divided randomly into three groups, A group was routine midazolam in-fusion sedation group, B group was midazolam target - controlled infusion sedation group, C group was midazolam target - controlled infusion sedation group on the feedback of bispectral index.II. Method Patients 'HR, EGG,BP,SPO2, BIS were monitored continuously. The sedation began when Ramsay sedation scores was 4 and BIS was 70. A group was routine midazolam infusion sedation group,and bolus dose was 0. 04mg . kg-1 maintenance dose was 0. 06mg . kg-1 . h-1 (6 - 8ml . h-1). The level of sedation was assessed by Ramsay sedation scores, the depth of ideal sedation was Ramsay sedation score 4. B group was midazolam target - controlled infusion sedation group. The initial target blood drug concentration was 60ng/ml,the depth of ideal sedation was the same as A group. C group was midazolam target - controlled infusion sedation group on the feedback of bispectral index. The initial target blood drug concentration was the same as B group, the computer adjusted the infusion pump on the basis of BIS. Fentanyl was given for analgesia, bolus dose was 0.4ug . kg-1, maintenance dose was 0. 8ug.kg-1 . h-1.III. The conformation and run manier of TCI system The software PMZA of TCI was run by HXD -I, connecting with Graseby3500 infusion pump. The software was run by MS - DOS, administration begin through the infusion pump controlled by software after the patient's age,body weight,target blood drug concentration were inputed.IV. Arterial blood samples were taken from B,C groups to measure plasma midazolam concentration. V. The plasma midazolam concentration was determinate by high performance liquid chromatography (HPLC).VI. All of the patients were had drug stopped when sedation ended, and tried to leave breathing machine when the autonomousbreathing was well recovered, the superficial spiro - index < 105 was successful for leaveing breathing machine. The trachea! intubation was extubated when Ramsay sedation scores was 2.VII. Statistics The effect of TCI was assessed by perform error,bias, degree of accuracy and wobble. The bias was expressed by median performance error (MDPE) ,the degree of accuracy was expressed by median absolute performance error ( MDAPE). The MDPE <20% and MDAPE <30% may be accepted by clinic. The results of measurement data were expressed by mean ?standard deviation ( x s ) ,the difference between two groups was checked by student - t test, which has statistics significance forP <0.05. Enumeration data was checked by X test, which has statistic significance forP <0. 05. The linear correlation analysis was used for true measure of blood drug concentration and Ramsay sedation scores, and the hypothesis test was used for correlation coefficient.ResultsI . There was not significant difference in the general state of three groups( P > 0.05 ).II. The MDPE of the system of TCI was 12.5% ,the MDAPE was 22.5%.HI. There were not significant difference in the sedation time and midazolam doses of three...