Correlation Analysis Between Perfusion Index And Total Peripheral Resistance Index

Objective To analyze the correlation between Perfusion Index(PI)and Total peripheral resistance Index(TPRI),and discuss the feasibility of using PI to monitor or evaluate Total peripheral resistance(TPR).Methods Patients aged 18 to 60 years old,ASA I to II,who underwent elective surgery with general anesthesia and whose SBP decreased by more than 20% or < 80 mm Hg from the period after endotracheal intubation mechanical ventilation to the period before surgical skin cutting were selected.Thoracic surgery,irregular heart beating rhythm,PI < 1 after entering the operating room,and the hand surface temperature could not be measured were excluded.Noninvasive Cardiac Output Monitoring(NICOM)and Philips Monitor Intellivue MP50 were used to monitor the hemodynamic parameters.After intravenous anesthetic induction,effect-chamber target-controlled infusion of propofol 2μg/ml 、 sufentanil 0.4μg/kg and cisatracurium 0.2 mg/kg was sequential intravenous injection to maintain Cerebral State Index(CSI)of 45 ～ 60.Patients with hypotension after endotracheal intubation and mechanical ventilation were divided into two groups according to HR: phenylephrine group(P group: HR≥60)and dobutamine group(D group: HR≤59),constant intravenous infusion of phenylephrine 1 μg/kg/min or dobutamine 10 μg/kg/min until SBP rised to 80%～120% of baseline value.HR,SBP,MAP,DBP,Cardiac Output(CO),Stroke Volume(SV),Stroke Volume Variation(SVV),PI and TPRI were observed and recorded at five time points,:after entering the operating room,before endotracheal intubation,after endotracheal intubation,before and after the infusion of phenylephrine or dobutamine.Analyze and compare the hemodynamic changes between the two groups and the correlation between PI and TPRI.Results 75 patients were included in the statistical analysis: P group(n=45)and D group(n=30).Before endotracheal intubation,PI increased and TPRI decreased,and after endotracheal intubation,PI decreased and TPRI increased in both groups(P<0.05).In group P,PI,HR and CO decreased(P < 0.05),while SBP,MAP,DBP and TPRI increased(P<0.05)after the infusion of phenylephrine.PI was negatively correlated with TPRI(r =-0.31,P<0.05)and TPRI was positively correlated with SBP,MAP and DBP(r = 0.81,0.79,0.80,P<0.05)before and after the infusion of phenylephrine.In group D,PI,TPRI,SBP,MAP,DBP and HR were increased after dobutamine infusion(P < 0.05),while SV and CO had no significant changes(P>0.05).There was no correlation between TPRI and PI before and after dobutamine infusion(r = 0.12,P>0.05),and TPRI was positively correlated with SBP,MAP and DBP(r = 0.68,0.65,0.68,P<0.05).Conclusion There was a negative correlation between PI and TPRI during the transfusions of norepinephrine.In addition,PI and TPRI showed an opposite trend during the induction period of general anesthesia,and the change of PI could preliminarily reflect the change trend of TPR.