Accuracy of stoke volume variation in prone position for assessment of blood volume in patients undergoing spine surgery: determination using FloTrac/Vigileo and Picco-plus technologies / 中华麻醉学杂志

ABSTRACT

Objective To evaluate the accuracy of stoke volume variation (SVV) determined using FloTrac/Vigileo and Picco-plus technologies in prone position for assessment of the blood volume in the patients undergoing spine surgery,Methods Forty-three ASA physical status Ⅰ-Ⅲ patients of both sexes,aged ＞ 18 yr,weighing 40-100 kg,scheduled for elective posterior approach to lumbar spinal fusion or scoliosis surgery were studied.After induction of anesthesia,a volume expansion was performed in supine and prone positions.Hydroxyethyl starch 130/0.4 sodium chloride injection 5 ml/kg was rapidly infused intravenously over 10 min to carry out the test for fluid responsiveness.Picco-plus and FloTrac/Vigileo systems were simultaneously applied in every subject to measure SVV (SVVP and SVVF).Positive fluid responsiveness was defined as the changing rate of stroke volume index ≥ 10％ as measured by using Piccoplus system.The patients were divided into response group (Rs group) and non-response group (NRs group) according to the changing rate of stroke volume index ≥ 10％ and ＜ 10％.The receiver operating characteristic (ROC) curve for SVV was plotted,and the diagnostic threshold,area under the ROC curve and 95％ confidence interval (CI) were calculated.Results Forty-one patients were included for analysis in this study.In supine position,the area under the ROC curve for SVV in predicting the fluid responsiveness was 0.740 (95％ CI0.568-0.913),the diagnostic threshold was 12％,and the sensitivity and specificity in determining fluid responsiveness were 86％ and 54％,respectively,for SVVF,and the area under the ROC curve was 0.637 for SVVP.In prone position,the area under the ROC curve was 0.451 for SVVF,and 0.634 for SVVP.Compared with Rs group,the baseline value of SVVFwas significantly lower,and no significant change was found in the other hemodynamic parameters before volume expansion in supine position in NRs group.There was no significant difference in the hemodynamic parameters before volume expansion in prone position between the two groups.Conclusion SVV determined by using FloTrac/Vigileo and Picco-plus systems in prone position can not accurately assess the blood volume in the patients undergoing spine surgery.