Study Of Correlation Between Ultrasound-Measured Diameter And Blood Flow Rate Of Internal Jugular Veins With The Preoperative Blood Volume In Elderly Patients

Objective:To explore the correlation between the diameter and blood flow rate of the internal jugular vein and the preoperative blood volume in elderly patients,and to provide proof for rapid evaluation of preoperative blood volume with ultrasonography in elderly patients.Materials and methods:Thirty patients,over 65 years old,scheduled for general anesthesia,ASA grade I II degree,before anesthesia,measured the central venous pressure(CVP)in right internal jugular vein,and measured the maximum diameter(Dmax)and minimum diameter(Dmin)by M type ultrasonic in left internal jugular vein on the cricoid cartilage plane,and calculate the respiratory variation index(RVI),(Dmax-Dmin)/Dmax × 100%,at the same time measured the maximum blood flow rate(BVmax)and the minimum blood flow rate(BVmin)by Doppler ultrasound in left internal jugular vein,and calculate the blood flow variation index(BVI),(BVmax-BVmin)/BVmax×100%,recorded the central venous pressure;then the patients were given the crystal liquid in 5 ml/kg,measured relevant data again and recorded,compared the data before and after infusion,explored the correlation between each data and central venous pressure,and drew the ROC curve to evaluate the efficiency of Dmax,Dmin,RVI,BVmax,BVmin and BVI in predicting CVP as 6 mmHg.Result:Dmax,Dmin,BVmax and BVmin were positively correlated with CVP(p<0.01);and RVI was negatively correlated with CVP(p<0.01);BVI is negative correlated with the CVP,but there was no statistically significant difference(p>0.05);through the analysis of ROC curve,Dmax,Dmin,RVI,BVmax and BVmin could be used to predict the CVP in patients,and the best data was BVmax(diagnostic thresholds before infusion were 8.72 cm/s,the sensitivity was 90%,specificity was 90%,Youden index was 0.800,the area under the ROC curve was 0.955;diagnostic thresholds after infusion were 7.97 cm/s,the sensitivity was 100%,specificity was 88.9%,Youden index was 0.889,the area under the ROC curve was 0.949);BVI diagnostic performance is poorer.Conclusion:Ultrasonic measurement of internal jugular vein diameter,respiratory variability and blood flow rate was correlated with preoperative blood volume in elderly patients,which can be used to evaluate the preoperative blood volume in elderly patients.