Fig. 3. Changes over time in urinary excretion of albumin in the four groups. Individual (open symbols) and mean ± SD values (closed symbols) are shown. Note the logarithmic scale used in this graph. The dotted line represents the upper limit of the reference range (30 mg/24 h). Urinary excretion of albumin in the low-flow sevoflurane (LS) group was significantly higher than in the other groups on days 1–5 after anesthesia. * P < 0.05 compared with each preoperative value. ** P < 0.01 compared with each preoperative value. †P < 0.05, ††P < 0.01 compared with the LS group. LSP = low-flow sevoflurane plus probenecid; HSP = high-flow sevoflurane plus probenecid; HS = high-flow sevoflurane.