Fig. 2.

Changes in mean arterial pressure (a) and heart rate (b) over time during surgery. Patients were administered 1000 mL of Ringer’s lactate solution for 20 min (infusion rate of 50 mL/min), followed by continuous infusion at a rate of 6 mL/kg/h. The dotted lines are the individual values, and the red solid lines are the locally weighted scatterplot smoothing (LOWESS) curves. In total, 20,084 segments were calculated with time ranging from 0 to 180 min, and the number of points in the smoothing window was 10. The time point at which 1000 mL of Ringer’s lactate solution was initiated was set as the reference time 0