Assessment of Stroke Volume Variation Perioperatively by Using Arterial Pressure with Cardiac Output

OBJECTIVE: To observe the sensitivity of stroke volume variation (SVV) for assessing volume change during induction period of general anesthesia. METHODS: Patients who underwent orthopaedic surgery under general anesthesia and mechanical ventilation were divided into two groups randomly. Patients in the group Ⅰwere subjected to progressive central hypovolemia and correction of hypovolemia sequentially; patients in the Group Ⅱ were exposed to hypervolemia alone. Each step was implemented after 5 minutes when the hemodynamics was stable. SVV and cardiac index (CI) were recorded, and Pearson's product-moment correlation was used to analyze correlation between SVV and CI. RESULTS: Forty patients were included in this study, 20 cases in each group. For group Ⅰ patients, SVV was increased significantly along with blood volume reduction, and changes in CI were negatively correlated with changes in SVV (r=-0.605, P<0.01); SVV decreased significantly along with correction of blood volume; changes in CI were negatively correlated with changes in SVV (r=-0.651, P<0.01). For group Ⅱ patients, along with blood volume increase, SVV did not change significantly; changes in CI revealed no significant correlation with changes in SVV (r=0.067, P>0.05). CONCLUSION: SVV is a useful indicator for hypovolemia, but not for hypervolemia.