A Study On The Correlation And Sensitivity Of Tip Perfusion Index And Stress Response In Different Populations Undergoing Laparoscopic Surgery

Objective:To investigate the sensitivity of tip perfusion index（TPI）to the stress stimuli in different patients undergoing selective laparoscopic cholecystectomy（patients with hypertension,diabetes and without co-disease）,and correlation of TPI with traditional indexes such as blood pressure,heart rate and stress hormones.Methods:A total of 75 patients,ASAⅠ～Ⅲ,undergoing selective laparoscopic cholecystectomy were assigned into three groups according to their comorbidity,group H with hypertension,group D with diabetes and group N without co-disease（n=25,each group）.Continuous monitoring of electrocardiography,noninvasive blood pressure,pulse oximetry,TPI,bispectral index and temperature were performed in all patients throughout operation.General anesthesia was induced with midazolam（0.02mg/kg）,etomidate（0.2mg/kg）,sufentanil（0.5μg/kg）and cisatracurium（0.15mg/kg）.After anesthesia induction and tracheal intubation,the patients were ventilated mechanically（V_T6-10ml/kg,RR12rpm）.P_ETCO₂ were maintained at35-45mm Hg.Anesthesiadepthweremaintainedwith remifentanil（0.1-0.3μg/kg/min）and propofol（4-12mg/kg/h）to keep the bispectral index between 40-60.CO₂ pneumoperitoneum pressure were set on12mm Hg to facilitate surgery procedure.Data including SBP,DBP,HR and TPI were recorded at each time point as following:rest state in operating room（T₀）,1min before tracheal intubation（T₁）,immediately after tracheal intubation（T₂）,1min before pneumoperitoneum（T₃）,1min and 5min after pneumoperitoneum（T₄,T₅）.The response time to stimuli and positive number to stress response according to criteria respectively were also recorded.Blood sample from five patients in each group were collected randomly to detect concentration of stress hormones including epinephrine（E）,norepinephrine（NE）and cortisol（COR）)at T₀-T₄ time points.Results:1.The change tendency of each index before and after stress response in three groups were same.Compared with T₁,blood pressure and heart rate increased at T₂（P<0.05）,TPI decreased（P<0.05）.Compared with T₃,blood pressure and heart rate increased at T₄,T₅（P<0.05）,while TPI decreased（P<0.05）.2.TPI was negatively correlated with SBP,DBP and HR,respectively.r=-0.375,-0.443,-0.212,in Group N;r=-0.285,-0.463,-0.425,in Group H;r=-0.201,-0.222,-0.163,in Group D（P<0.01,0.05）.TPI was negatively correlated with epinephrine in Group N,r=-0.407（P<0.05）,while no obvious correlations were found between TPI and NE or COR,r=-0.145,-0.058 respectively（P>0.05）,There were no significant correlations between TPI and stress hormones（NE,E,COR）in other two groups.the correlation coefficient were r=-0.264,-0.078,-0.234 in Group H,r=-0.262,-0.148,-0.043 in Group D respectively（P>0.05）.3.Before and after tracheal intubation（T₁～T₂）and establishment of pneumoperitoneum（T₃～T₄）,the proportions of each monitoring indicator with positive stress response based on their criteria were TPI 100%,SBP 70%,DBP72%,HR 64%in Group N;TPI 100%,SBP 64%,DBP 60%,HR 56%in Group H;TPI 100%,SBP 60%,DBP 64%,HR 50%in Group D.Compared with SBP,DBP and HR,the positive stress response rate of TPI was higher,（P=0.00）,and the response time was shorter,the magnitude was larger（P<0.05）.Conclusion:1.In different population,TPI is negatively correlated with SBP,DBP and HR.The sensitivity of TPI is significantly higher than that of SBP,DBP and HR.2.TPI is a high sensitive,non-invasive,real-time and continuous monitoring indicator to stimuli.TPI is also applicable in population with hypertension or diabetes.