Predictive Effect Of Perfusion Index And Carotid Artery Correction Blood Flow Time In Elderly Patients With Hypotension After Spinal Anesthesia

Objective:To analyze the relationship between upper and lower limb perfusion index（PI）and baseline corrected carotid flow time（FTc）and the occurrence of hypotension（SAIH）in elderly patients before and after spinal anesthesia,and to explore the predictive value of PI and FTc in elderly patients with SAIH.Methods:128 elderly patients,aged≥65 years,undergoing elective hip/knee arthroplasty under spinal anesthesia were selected.BMI18.5～25.0Kg/m~2,American Association of Anesthesiologists（ASA）gradeⅡ～Ⅲ,hypertension patients’blood pressure was adjusted below 160/100mm Hg before operation.FTc of right common carotid artery was measured by ultrasound in all patients in the preanesthesia room.After entering the operating room,the PI of the left index finger and left second toe and the baseline values of systolic blood pressure（SBP）,diastolic blood pressure（DBP）,mean arterial pressure（MAP）and heart rate（HR）were obtained.The PI of the upper and lower extremities during 5min after subarachnoid administration and the above hemodynamic parameters from intraspinal administration to skin incision were recorded.The patients were divided into non-hypotension group（group N）and hypotension group（group H）according to whether the SBP decreased below 80%of the baseline during this period.To analyze the relationship between PI of upper and lower extremities,baseline FTc and the occurrence of SAIH in elderly patients before and after spinal anesthesia.Results:1.Compared with N group,the group H patients who are older,higher basic HR faster,5 min after lumbar hemp upper limb PI when compared to the baseline lower amplitude is bigger,the FTc is more（P<0.05）.2.Baseline FTc lumbar hemp,basic HR,5 min after upper limb PI decline rate is older patients SAIH independent factors（P<0.05）.The decrease rate of upper limb PI and basic HR were positively correlated with hypotension,while baseline FTc was negatively correlated with hypotension.3.The areas under the working characteristic curve（AUC）between baseline FTc,basic HR,5 min after lumbar hemp upper limb PI decline rate before and after spinal anesthesia and SAIH of elderly patients were 0.831,0.725 and 0.748,respectively.Among them,the specificity and sensitivity of basic HR are low,the sensitivity is75.5%,the specificity is 66.2%,the cutoff value is 74.5;the sensitivity of upper limb PI decline rate is 75.5%,the specificity is 74.6%,the cutoff value is 26.3;and the sensitivity of baseline FTc is 71.8%,and the specificity is 83.7%,the cutoff value is328.5.The combined prediction of the three indexes showed that AUC was 0.884.Conclusion:Basic HR>74.5bpm,upper limb PI decrease rate>26.3%during 5min after SA,and baseline FTc<328.5ms have certain predictive value for the occurrence of SAIH in elderly patients.Among them,the predictive specificity of FTc is the highest,and the combined application of the three indicators can improve the predictive effect of SAIH in elderly patients.