Stroke volume variation as a predictor of fluid responsiveness in patients undergoing one-lung ventilation.

OBJECTIVES To investigate the ability of stroke volume variation (SVV) calculated by the Vigileo-FloTrac system (Edwards Lifescience, Irvine, CA) to predict fluid responsiveness in patients undergoing one-lung ventilation (OLV). DESIGN Prospective, observational study. SETTING Clinical hospital. PARTICIPANTS Thirty patients scheduled for a pulmonary lobectomy requiring OLV for at least 1 hour under combined epidural/general anesthesia. INTERVENTIONS After starting OLV, hydroxyethyl starch, 500 mL, was administered for 30 minutes. MEASUREMENTS AND MAIN RESULTS Hemodynamic variables including heart rate, mean arterial pressure, cardiac index, stroke volume index (SVI), and SVV were measured before and after volume loading. SVV before volume loading was significantly correlated with the absolute changes in SVV (ΔSVV) and percentage changes in stroke volume index (ΔSVI) after volume loading (ΔSVV: p < 0.05, r = -0.893; ΔSVI: p < 0.05, r = 0.866). Of the 30 patients, 15 (50%) were responders to intravascular volume expansion (an increase in SVI ≥ 25%), and 15 (50%) were nonresponders (an increase in SVI <25%). The area under the ROC curve was 0.900 for SVV (95% confidence interval, 0.809-0.991), whereas the optimal threshold value of SVV to discriminate between responders and nonresponders was 10.5% (sensitivity: 82.4%, specificity: 92.3%). CONCLUSIONS The authors found that SVV measured by the Vigileo-FloTrac system was able to predict fluid responsiveness in patients undergoing surgery with OLV with acceptable levels of sensitivity and specificity.