Fig. 1

Schematic representation of the study protocol. Time zero (T₀) was the starting point of septic shock fluid resuscitation and defined as the first time that MAP < 65 mmHg or serum lactate > 2 mmol/l during the ICU stay. According to the different range of initial fluid resuscitation rate (equal to the slope in the graph), the cohort was divided into four groups: group 1 (≥ 0.5 ml/kg/min), group 2 (0.25–0.5 ml/kg/min), group 3 (0.17–0.25 ml/kg/min), and group 4 (< 0.17 ml/kg/min). The “” on the timeline marked ICU admission, shock reversal time (T_r), and ICU and hospital discharge; shock reversal time (T_r), ICU discharge, and hospital discharge must be after T₀ but had no fixed time relationship with T₀. The main variables and measurements of the study are shown in the bottom half of the figure. The period of shock reversal was defined as the duration between T_r and T₀ (abbreviation: ICU = intensive care unit; T₀ = time zero; T₃ = 3 h after T₀; T_r = shock reversal time; VIS = Vasoactive-Inotropic Score; LOS = length of stay)