Evaluation of Hemodynamics During Posture Change to Knee-Chest Position by FloTracTM

In order to evaluate changes in hemodynamics, a FloTracTM system was used during posture change from supine to knee-chest position. Thirty-five patients undergoing lumbar surgery participated in this study. Anesthesia was performed with total intravenous anesthesia using propofol and remifentanil. Cardiac index (CI), stroke volume index (SVI), and stroke volume variation (SVV) were measured by using FloTracTM in addition with heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean blood pressure (MBP). The values before and after postural change were compared. SVV increased immediately after posture change and remained high. With posture change to the knee-chest position, HR, DBP and SVV increased and SBP, CI and SVI decreased. An increase in SVV from immediately after postural change indicated that SVV did not reflect circulating blood volume.