Page 11 - 麻醉与监护论坛2015年第4期

Body Position Changes Influence Stroke Volume Variation in
Mechanically Ventilated Patients with Sepsis

Dai-hua Yu

Intensive Care Unit, Tangdu Hospital, The Fourth Military Medical University, Xi’an 710000, China

Abstract

Objective: To investigate the effect of body position changes on the SVV in ventilated patients with sepsis.
Methods: Sixty-six 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 positions. In addition to standard hemodynamic monitoring, SVV, central venous pressure(CVP), cardiac
index(CI), stroke volume index(SVI), global end-diastolic volume index(GEDVI) and global ejection fraction(GEF) were recorded at each position after
stabilization.
Results: SVV had strong negative correlation with CI, SVI, GEF and GEDVI(P<0.0001). After the change to the 30° head-up or the prone position,
SVV increased significantly, while CI, SVI, GEF and GEDVI decreased dramatically. SVV in the supine position did not correlate with 30° head-up or
prone induced changes in CI(P<0.05). All variables did not differ between 30° left or right recumbent and supine position.
Conclusions: Body position changes may affect the correlation of SVV with hemodynamic variables. The 30° head-up and prone position increased
SVV due to the associated decreased stroke volume. The 30° left or right recumbent positions do not affect SVV and stroke volume.
Key words:stroke volume variation; body position change; sepsis

Introduction administration has deleterious effects such as worsening
gas exchange, hemodilution and cardiac overload.
Maintenance of hemodynamic stability and the Consequently, volume expansion must be conducted
critical organ perfusion are crucial to the treatment of in septic patients with an effective predictor to improve
patients with sepsis[1]. In patients undergoing sepsis, the hemodynamic function.
severe infection and sepsis increased vessel permeability,
allowing intravascular plasma to move into the interstitial Static cardiac preload variables, such as central venous
compartment. Therefore, both are associated with the pressure(CVP), often fail to provide reliable information on
decreased intravascular blood volume and impaired cardiac preload and are not capable of predicting a cardiac
perfusion of critical organs. Aggressive fluid infusion is response to fluid therapy[2]. In contrast to static preload
critically important for supporting cardiac and respiratory variables, dynamic preload variables, such as stroke volume
function in septic patients. However, excessive fluid variation(SVV), are based on heart-lung interactions for

Laboratory and ClinicalCIonverstTighaetsiiosn 92 FAM 2015 Mar/Apr Vol.22 Issue 2