The effect of body position changes on stroke volume variation in 66 mechanically ventilated patients with sepsis

Abstract

PurposeThe aim of the study was to investigate the effect of body position changes on the stroke volume (SI) variation (SVV) in ventilated patients with sepsis. MethodsSixty patients with sepsis were studied during mechanical ventilation. All patients were randomly placed in the supine, 30° head-up, 30° left or right recumbent, or prone position. In addition to standard hemodynamic monitoring, SVV, central venous pressure, cardiac index (CI), SV index (SVI), global end-diastolic volume index (GEDVI), and global ejection fraction (GEF) were recorded at each position after stabilization. ResultsStroke volume variation had strong negative correlation with CI, SVI, GEF, and GEDVI (P < .0001). After the change to the 30° head-up or the prone position, SVV increased significantly, whereas CI, SVI, GEF, and GEDVI decreased dramatically. Stroke volume variation in the supine position did not correlate with 30° head-up– or prone-induced changes in CI (P < .05). All variables did not differ between 30° left or right recumbent and supine positions. ConclusionsBody position changes may affect the correlation of SVV with hemodynamic variables. The 30° head-up and prone positions increased SVV because of the associated decreased SV. The 30° left or right recumbent position does not affect SVV and SV.