Accuracy of aortic valve velocity time integral in assessing fluid responsiveness during general anesthesia in elderly patients

Objective To evaluate the accuracy of aortic valve velocity time integral (VTI) in assessing fluid responsiveness during general anesthesia in elderly patients. Methods Forty-four elderly patients of both sexes, aged 65-80 yr, of American Society of Anesthesiologists physical status Ⅰ-Ⅲ, with New York Heart Association classⅠ or Ⅱ, undergoing elective surgery with general anesthesia in our hospital from February 2018 to August 2018, were enrolled in this study.All the patients underwent tracheal intubation after general anesthesia induction, and then volume expansion was carried out (6% hydroxyethyl starch 250 ml was intravenously infused for 30 min). The heart rate (HR), mean arterial pressure (MAP), VTI and stroke volume (SV) were recorded before and after volume expansion, and ΔHR, ΔMAP, ΔVTI and ΔSV were calculated.Patients were divided into 2 groups according to ΔSV: response group (R group, ΔSV≥15%) and non-response group (NR group, ΔSV<15%). The receiver operating characteristic curve (with the area under the standard ΔSV curve was 1) was used to analyze the ΔHR, ΔMAP and ΔVTI, and the Youden index at its best was calculated.The Person test was used to analyze the correlation between ΔVTI and ΔSV. Results There were 25 cases in R group and 19 cases in NR group.Compared with group NR, ΔHR was significantly decreased, and ΔVTI and ΔSV were increased in group R (P<0.05). The area under the ROC curve of ΔHR, ΔMAP and ΔVTI in assessing fluid responsiveness was 0.509 (95% confidence interval 0.314-0.689, P=0.415), 0.558 (95% confidence interval 0.379-0.737, P=0.515) and 0.905 (95% confidence interval 0.812-0.999, P<0.01), respectively. When Youden index was at its best, ΔVTI was 15.28%, with the sensitivity 88.0% and specificity 94.7%.There was a positive correlation between ΔSV and ΔVTI (r=0.936, P<0.05). Conclusion ΔVTI can accurately assess the fluid responsiveness during general anesthesia in elderly patients. Key words: Aortic valve; Aged; Fluid therapy