Clinical Study On Monitoring Sedation Depth Of Dexmedetomidine With Conview Depth Of Anesthesia Monitor

Purpose:This study first evaluated the accuracy of Conview anesthesia depth monitor in monitoring the sedation degree of dexmedetomidine during perioperative period;On this basis,under the guidance of Conview anesthesia depth monitor,the sedative effects of dexmedetomidine and propofol were compared,so as to provide clinical reference for the selection of sedative drugs during combined spinal epidural anesthesia.Method:Part Ⅰ:60 patients with elective knee surgery in our hospital,regardless of gender,aged 50～80 years,ASA grade Ⅰ or Ⅱ.The depth of sedation of dexmedetomidine was monitored by vigilance/sedation score(OAA/S score),bispectral index(BIS)and Conview anesthesia depth monitor.Select L2-3 or L3-4 intervertebral space for puncture,give combined spinal epidural anesthesia,and adjust the anesthesia plane at T10-S5.After the anesthesia plane was fixed,the operation position was set,and dexmedetomidine 2 ug·kg-1·h-1 was injected intravenously for 15 minutes.Then,the pump was injected to maintain the dose of 0.75 ug·kg-1·h-1 until the drug was stopped 15 minutes before the end of the operation.Record the heart rate,blood pressure,BIS value and Ai value after entering the room as the basic value,and record the immediate OAA/S score.From the infusion of dexmedetomidine to the end of the operation,BIS value,Ai value,heart rate(HR)and blood pressure(map)were recorded every 10 minutes.OAA/S score was performed immediately after recording.Part Ⅱ:60 patients with hip and knee arthroplasty under combined spinal epidural anesthesia in our hospital,regardless of gender,aged 50～80 years,ASA grade Ⅰ or Ⅱ.Conview anesthesia depth monitor and OAA/S score were used to monitor the sedation depth of propofol or dexmedetomidine.The patients undergoing combined spinal epidural anesthesia were randomly divided into two groups:Propofol group(group A)and dexmedetomidine group(group B).Select L2-3 or L3-4 intervertebral space for puncture,give combined spinal epidural anesthesia,and adjust the anesthesia plane at T10-S5.After the anesthesia plane was fixed,the operation position was arranged.In group A,propofol 2 mg·kg-1 was injected intravenously and the dose was maintained at 1～2 mg·kg·1·h-1 until the drug was stopped 15 minutes before the end of the operation;In group B,dexmedetomidine 2 ug·kg-1·h-1 was injected intravenously for 15 minutes,and the dose was maintained at 0.75 ug·kg-1·h-1 until it was stopped 15 minutes before the end of the operation.Maintain the AI value at 80～90.Observe and record:① AI value,heart rate and blood pressure after entering the operating room(T0),skin breaking(T1),prosthesis beating(T2),bone cement injection(T3),and at the end of operation(T4).OAA/S score shall be performed immediately after recording;②Operation duration,dosage of dexmedetomidine or propofol and whether auxiliary drugs are used;③The occurrence of adverse reactions such as hypotension,bradycardia,respiratory depression,nausea and vomiting were recorded.Result:Part Ⅰ:BIS value,Ai value and OAA/S score have high correlation,which are positively correlated.The correlation coefficient between BIS value and Ai value was 0.772(P<0.05).The correlation coefficients between BIS value,Ai value and OAA/S score were 0.970 and 0.967 respectively(P<0.05).When OAA/S score≥ 3,the best cut-off value of BIS value is 80,the sensitivity is 95.8%,and the specificity is 81.3%.The best cutoff value of Ai value is 82,the sensitivity is 98.6%,and the specificity is 81.7%.Part Ⅱ:compared with propofol group,all patients were awake at T0,and there was no difference in OAA/S score.At T1-4,the OAA/S score of dexmedetomidine group was higher.Compared with propofol group,dexmedetomidine group had higher incidence of bradycardia(P<0.05)and lower incidence of respiratory depression(P<0.05).There was no significant difference in the incidence of hypotension,nausea and vomiting between the two groups(P>0.05).Conclusion:1.Conview anesthesia depth monitor can accurately monitor the sedation depth of dexmedetomidine under combined spinal epidural anesthesia.There is no significant difference compared with BIS.It can accurately monitor the sedation depth of patients.2.Conview anesthesia depth monitor has high sensitivity in monitoring dexmedetomidine.Compared with propofol,dexmedetomidine hardly causes respiratory depression,and has stable hemodynamics,less adverse reactions and higher safety.It is more suitable forsedation under combined spinal epidural anesthesia,but it should prevent bradycardia.