Passive Leg Raising Is Predictive Of Fluid Responsiveness In Patients With Severe Sepsis

Rapid fluid loading is the usual treatment for symptomatic hypovolemia. But the assessment of volume responsiveness and the decision to administer a fluid bolus is a common dilemma facing physicians caring for critically ill patients. Because volume expansion does not always improve hemodynamic status, predictive parameters of fluid responsiveness are needed. Static markers of cardiac preload are poor predictors of volume responsiveness, and dynamic markers are often limited by the presence of spontaneous respirations or cardiac arrhythmias. Passive leg raising (PLR) is a reversible maneuver that mimics rapid fluid loading and increases cardiac preload.Objective:To investigate the hemodynamic responsiveness to passive leg raising in mechanically ventilated patients with severe sepsis.Methods:We investigated28mechanically ventilated patients with severe sepsis, considered for volume expansion. We assessed hemodynamic status in a semi-recumbent position, after passive leg raising, and after volume expansion (500mL6%hydroxyethyl starch infusion within30mins). Measurements of indices were obtained with pulse indicator continuous cardiac output (PiCCO) system. Fluid responsiveness was defined as the changes in stroke volume index (SVI) increase after fluid loading (△SVI)≥15%.Results:Among28patients included in this study,18had a stroke volume increase of≥15%after volume expansion (responders). Systolic artery blood pressure was significantly increased by PLR from (100.1±18.1) mmHg to (115.9±13.1) mmHg (1mmHg=0.133kPa, P<0.01) among the responders, mean artery blood pressure was significantly increased by PLR from (68.1±12.4) mmHg to (77.8±13.0) mmHg (P<0.05), and mean central venous pressure was significantly increased by PLR from (7.2±3.4) mmHg to (10.1±4.1) mmHg (P<0.05), similar with the results after fluid loading. The stroke volume index increase≥10.5%after PLR predicted fuid responsiveness with sensitivity of72.2%and specificity of90%.Conclusions:Changes in stroke volume index induced by passive leg raising are accurate and interchangeable indices for predicting fluid responsiveness in mechanically ventilated patients with severe sepsis.