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

Abstract

Purpose: The 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.

Methods: Sixty 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.

Results: Stroke 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.

Conclusions: Body 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.