Evaluation of the fluid responsiveness in patients with septic shock by ultrasound plus the passive leg raising test

Abstract

Background: Prompt, accurate, and noninvasive prediction of fluid responsiveness is still lacking in intensive care unit. This study is to investigate the value of the Doppler ultrasound evaluation of variation in brachial artery peak velocity (VVpeak_brach) and passive leg raising (PLR)-induced changes in the brachial artery peak velocity (ΔVpeak_PLR) in predicting the fluid responsiveness in mechanically ventilated patients with severe sepsis or septic shock.

Methods: A prospective study was conducted involving 62 patients. Semirecumbent positioning, PLR, and a return to the semirecumbent position were performed with all patients before volume expansion. VVpeak_brach, ΔVpeak_PLR, and stroke volume were observed by Doppler ultrasound. A patient with an increase of ≥15% in the stroke volume on volume expansion was defined as a responder. The predictive value was evaluated on the receiver operating characteristic curve analysis.

Results: A total of 28 patients were classified as responders. The area under the receiver operating characteristic curve of ΔVpeak_PLR and VVpeak_brach was 0.898 and 0.891, respectively. A ΔVpeak_PLR value of more than 10.6% predicted the fluid responsiveness with a sensitivity of 82.1% and a specificity of 88.2%. A VVpeak_brach value of more than 10.95% predicted the fluid responsiveness with a sensitivity of 78.6% and a specificity of 91.2%. The positive predictive value was 94.4% when both were positive. In contrast, the negative predictive value was 96.6%.

Conclusions: Doppler ultrasound evaluation of VVpeak_brach and ΔVpeak_PLR could be a feasible method for the noninvasive assessment of fluid responsiveness in mechanically ventilated patients with severe sepsis or septic shock. The combination of two indicators can improve the predictive value.

Keywords: Fluid responsiveness; Passive leg raising; Ultrasound.