Feasibility Study Of Photoelectric Volume Pulse Wave Amplitude In Evaluating Preoperative Anxiety And Depth Of Sedation Of Patients

Objective:To observe the alteration of finger photoplethysmographic amplitude(PPGA)in patients undergoing surgical operation and anesthesia,and to discuss the feasibility of finger photoplethysmographic amplitude in monitoring anxiety levels compared with the anxiety rating scales.Methods:After informed consent has been written,120 patients(American Society of Anesthesiologists physical status I,aged 18～65 years old)were recruited from elective surgery except hyperthyroidism.Once patients arrived in the operating room,routine monitoring including heart rate,systolic pressure,diastolic pressure,and saturation of pulse oximetry,were arranged.HR,SBP,DBP measurements were otbained.Once the finger photoplethysmogram become stable,the PPGA value wasmanually recorded and took the average values in 6 seconds.Then the patients were assessed by the Ramsay scale and were asked to fill in the anxiety rating scales,which is the state part of State-Trait Anxiety Inventory(STAI-S)and Beck Anxiety Inventory(BAI).Results:The STAI-S score had significantcorrelations with SBP and PPGA,and the regression coefficient were 0.332(R2=0.370,95%CI-0.146,0.624)and-0.519(R2=0.146,95%CI-0.281,-0.825),In contrast,no statistical correlations between STAI-S score and HR or DBPwas found.A significant correlation was found betweenBAI score and PPGA,the regression coefficient were-0.79(R2=0.066,95%CI-1.341,-0.238).However,no obvious correlation was observed between BAI score and HR,SBP or DBP..Conclusion:The finger photoplethysmographic amplitude(PPGA)can provide some important signals for clinicians to access the preoperative anxiety in surgical patients.It has negativestatistical correlations with STAI-S and BAI scores.The finger photoplethysmographic amplitude provided the possibility to monitor the degree of anxiety in patients preoperatively.Further studies are need to comfirmwhether finger photoplethysmographic amplitude could be a new method to access the level of anxiety.Objective:To observe the viariation of finger photoplethysmographicamplitude(PPGA)in different level of sedation of surgical patients before anesthesia induction and toclarify the feasibility of finger photoplethysmographicamplitude in monitoring depth of sedition compared with the Ramsay score.Methods:One hundred patients ASA Ⅰ～Ⅱ patients aged 18～65 undergoing surgical operation under general anesthesia were randomized into two groups(propofol group,P group and dexmedetomidine group,D group)after informed consent written.Rounting monitoring were arranged in every volunteers.In the P group,propofol were administerd by a target-controlled infusion,and the concentration of target effect-site was set initially at 0.5ug/ml and increase in every 3minutes until 1.5 ug/ml.In the dexmedetomidine group,loading dose of dexmedetomidine was calculated by 0.6μg/kg/and completed in 10 minutes,then maintained for 20 minutes by 0.5μg/kg/h.In the P group,HR,SBP,DBP,PPGA were recorded and Ramsay score was evaluated at following time points:10min after into operation room(T0),3min after continuous infusion with 0.5ug/ml(T1),3min after continuous infusion with 1.0ug/ml(T2),3min after continuous infusion with 1.5ug/ml(T3).In the D group,All datas were recorded and the Ramsay score was evaluated after 10 min(T1),20 min(T2),30 min(T3),respectively.All of the data were analyzed offline.Results:In both of propofol and dexmedetomidine groups,the hemodynamic parameters,including HR,SBP and DBP gradually decreased,however,PPGA increased obviously and significant difference existed in any two time points(P<0.001).Further analysisfound significant correlationsbetween PPGA and Ramsay scores in two groups.Regression coefficients were 0.084(95%CI 0.063,0.104)in dexmedetomidine group,and 0.094(95%CI 0.070,0.117)in propofol group.Conclusion:The hemodynamic index decreased and PPGA significantly increased with treatment of different sedative medicine.The finger PPG signal can be used inpreoperativesedative depth assessment.PPGA hadsignificant correlations with the Ramsay score,whileblood pressure and heart rate were unreliable in sedation assessment.