Correlation Of Bispectral Index With Target-controlled Plasma Concentration Of Propofol And End-tidal Sevoflurane Concentration

Obiective:To research the multiple correlation and regression equation between bispectral index?BIS?and the plasma target concentration of propofol?Cp propofol?and end-tidal sevoflurane concentration(Et_sevo)in patients undergoing oral surgery during intravenous inhalational anesthesia.To provide the reference for rational use of drugs in clinical anesthesia.Method:Fourty adults classified as ASA physical status I^II,aged 18 to 65yr,Body Mass Index?BMI?from 18kg/m² to 30kg/m²,who undergoing oral surgery were enrolled in the study.Exclusion criteria:patients with severe heart,pulmonary,liver and kidney dysfunction;patients with neurological diseases that affect the level of consciousness;patients with a history of mental illness and long-term use of sedative and antidepressant drugs;severely obese patients;patients who are allergic to any drugs used in this study.Anesthesia induction:Rapid intravenous induction was used in all patients.sufentanil?0.5?g/kg?,etomidate?0.2mg/kg?,cis-atracurium?1.5mg/kg?were injected intravenously.At the same time,target-controlled infusion of propofol?plasma concentration was 1.5?g/ml and infusion time was 6min?.Tracheal intubation was performed when propofol reach the target concentration.After intubation,mechanical ventilation was maintained and remifentanil was administered by target-controlled infusion?effect-site concentration 0.5ng/ml?.Maintenance of anesthesia:The BIS value was controlled between 40 and 60,and propofol or sevoflurane was adjusted according to the BIS value and circulation index during surgery.After tracheal intubation,sevoflurane was inhaled at an initial concentration of 1Vol%increased or decreased by 0.2vol%each time,and the end-tidal sevoflurane concentration was controlled winin 1MAC.The initial plasma target concentration of propofol was 1.5 g/ml,with each increase or decrease of 0.1?g/ml.The effect-site target concentration of remifentanil ranged from 0.5ng/ml to 1.5ng/ml.Anesthesia recovery:At the end of operation,close sevoflurane and stop the infusion of propofol and remifentanil.Extubation was performed when the patients met the indications.Monitoring points:entering the room?T₀?,3min after induction?T₁?,6min after induction?T₂?,intubation immediately?T₃?,5min after intubation?T₄?,beginning of operation?T₅?,every 10min during operation(T₆-T₁₂),end of operation(T₁₃),extubation immediately(T₁₄),leaving the room(T₁₅).Monitoring indicators:The BIS value,plasma target concentration of propofol?Cp propofol?,end-tidal sevoflurane concentration(Et_sevo),end-tial carbon dioxide partial pressure?PetCO₂?,heart rate?HR?,systolic blood pressure?SBP?,diastolic blood pressure?DBP?,mean arterial pressure?MAP?.Anesthesia time,operation time,spontaneous breathing recovery time,eye opening time,extubation time,intraoperative use of vasoactive drugs were recorded.Patients were interviewed 24 hours after operation to evaluate intraoperative awareness,postoperative nausea and vomiting.The correlation analysis and multiple regression equation of BIS value,Cp propofol and Et_sevoevo were carried out by statistical software.Result:During the period of T₅-T₁₂,the Pearson correlation coefficient between BIS and Cp propofol was-0.872,the correlation coefficient between BIS and Et_sevoevo was-0.565.BIS was negatively correlated with Cp propofol and Et_sevo?P<0.01?.The multiple linear regression equation:y=76.241-16.414x₁-4.342x₂(x₁ stands for Cp propofol,x₂ for Et_sevo,y for BIS),the coefficient of determination R ²=0.794.Conclusion:1.During propofol combined with sevoflurane anesthesia,BIS was negatively correlated with Cp propofol and Et_sevo?P<0.01?.The multiple linear regression equation:y=76.241-16.414x₁-4.342x₂(x₁ stands for Cp propofol,x₂ for Et_sevo,y for BIS),the coefficient of determination R ²=0.794.2.The multiple linear regression equation can guide the safe and rational drug use of clinical anesthesia,and it has reference value.