Background Few studies have reported the effect of different volume responsiveness evaluation methods on volume therapy results and prognosis.This study was carried out to investigate the effect of two volume responsiveness evaluation methods,stroke volume variation (SW) and stroke volume changes before and after passive leg raising (PLR-ASV),on fluid resuscitation and prognosis in septic shock patients.Methods Septic shock patients admitted to the Department of Critical Care Medicine of Zhejiang Hospital,China,from March 2011 to March 2013,who were under controlled ventilation and without arrhythmia,were studied.Patients were randomly assigned to the SVV group or the PLR-ASV group.The SVV group used the Pulse Indication Continuous Cardiac Output monitoring of SW,and responsiveness was defined as SW-＞12％.The PLR-ASV group used ASV before and after PLR as the indicator,and responsiveness was defined as ASV ＞15％.Six hours after fluid resuscitation,changes in tissue perfusion indicators (lactate,lactate clearance rate,central venous oxygen saturation (SCVO2),base excess (BE)),organ function indicators (white blood cell count,neutrophil percentage,platelet count,total protein,albumin,alanine aminotransferase,total and direct bilirubin,blood urea nitrogen,serum creatinine,serum creatine kinase,oxygenation index),fluid balance (6-and 24-hour fluid input) and the use of cardiotonic drugs (dobutamine),prognostic indicators (the time and rate of achieving early goal-directed therapy (EGDT) standards,duration of mechanical ventilation and intensive care unit stay,and 28-day mortality) were observed.Results Six hours after fluid resuscitation,there were no significant differences in temperature,heart rate,blood pressure,SpO2,organ function indicators,or tissue perfusion indicators between the two groups (P ＞0.06).The 6-and 24-hour fluid input was slightly less in the SW group than in the PLR-ASV group,but the difference was not statistically significant (P ＞0.05).The SW group used significantly more dobutamine than the PLR-ASV group (33.3％ vs.10.7％,P =0.039).There were no significant differences in the time ((4.8±1.4) h vs.(4.3±1.3) h,P=0.142) and rate of achieving EGDT standards (90.0％ vs.92.9％,P =0.698),or in the length of mechanical ventilation and ICU stay.The 28-day mortality in the SW group (16.7％ (5/30)) was slightly higher than the PLR-ASV group (14.3％ (4/28)),but the difference was not statistically significant (P =0.788).Conclusions In septic shock patients under controlled ventilation and without arrhythmia,using SW or PLR-ASV methods to evaluate volume responsiveness has a similar effect on volume therapy results and prognosis.The evaluation and dynamic monitoring of volume responsiveness is more important for fluid resuscitation than the evaluation methods themselves.Choosing different methods to evaluate volume responsiveness has no significant influence on the effect of volume therapy and prognosis.