Anesth Analg: The effect of riffentani on the control performance of the bi-frequency index-controlled Bayesian closed-loop propofol administration system

Background and Objectivethis trial is based on model clinical studies, the establishment of patient individualized closed-loop (CL) control systems during propofol and rifentani anaesthetic induction and maintenance with dual spectrum index (BIS) as the control variable, and the effect of Refentanil's targeting site concentration (CeREMI) on its clinical performancemethodin 163 patients, propofol was administered using the CL system (BIS target (BISTARGET) between 40 and 50)According to clinical needs, 2 to 7.5 ng/mL is selected as the initial CeREMI targetThe performance parameters in the induction process are the time required to reach the target BIS for the first time, the time required to achieve the maximum drug effect after induction (TPEAK, BIS) and the corresponding BIS at this time, and the time required to recover the target BIS at the end of the inductionPerformance during anaesthetic maintenance is defined as the percentage between the case time of the target BIS and the target BIS, the performance error (PE) between the observation value and the target BIS value and its derived median PE (MDPE), as a measure of control bias, the median absolute PE (MDAPE) as a measure of control inaccuracy, the dispersion as a measure of the time-related trend of bIS value relative to the target BIS value, and the swing as a measure of the change in the subject's internal variation in the prediction errorThe secondary result is the hemodynamic stability of the patient during CL controloutcomeapplied CL system induces and maintains anesthesia within a clinically acceptable rangeThe percentage of case time (standard deviation (Standard Deviation(SD) and BIS s.10 for all study participants was 82% (14%)The average mDPE and MDAPE (SD) were -6.6% (5.5%) and 11.2% (5.5%, respectively)The study found negative dispersion ( -0.001 (0.004) and acceptable swings of 9.7% (4.0%)The correlation between the system PE and CeREMI is low and is only affected by CeREMI 2.8 ng/mLHemodynamicstability is within clinically acceptable rangesconcluding the CL system used for propofol administration during anesthesia in the range of 2.8 to 7.5 ng/mL has good results There is no evidence of a strong correlation between CeREMI and CL performance The study also showed that preventing ioptophenol anesthesia may be more challenging when CeREMI is below 2.8 ng/mL