The Clinical Research of Needle Electrodes Used in Bispectral Index to Monitor the Depth of Anesthesia

After the patient enters the room, non-invasive BP, HR, end-tidal CO2, SPO2 and other routine monitoring are performed, and the corresponding BIS electrodes are worn to the patient. The anesthesiologist decides whether to perform invasive hemodynamic monitoring, such as invasive arterial blood pressure monitoring, central venous pressure monitoring, etc., depending on the patient's condition and surgical requirements. The induction and maintenance of anesthesia is the routine scheme in the Second Affiliated Hospital of Zhejiang University , and the medication and dose are based on the judgment of the main anesthesiologist . After induction, endotracheal intubation was performed and mechanical ventilation was given. After anesthesia induction, install subcutaneous needle electrode to the patient. BIS values were collected using two BIS monitoring systems, one using the original BIS sensor and the other connected to the needle electrodes.During the operation, the anesthesiologist adjusted the depth of anesthesia according to the original BIS value, and propofol was used to improve the depth of sedation if the BIS value was greater than 60. In this study, surface acoustic wave electronic nose was used to monitor the exhaled propofol concentration of patients undergoing general anesthesia.The BIS value, hemodynamic information, exhaled propofol concentration and plasma propofol concentration were recorded.