Figure 6. Changes with time in 24-h urinary N-acetyl-[small beta, Greek]-D-glucosaminidase (NAG) excretion in the three groups. Individual (open symbols) and mean + standard deviation values (closed symbols) are shown (triangle = low-flow isoflurane, circle = low flow sevoflurane, square = high-flow sevoflurane; n = 14). The dotted line represents the upper limit of the reference range. Urinary excretion of NAG in both the low-flow sevoflurane and high-flow sevoflurane groups was significantly greater than in the isoflurane group after anesthesia. ##P < 0.01 compared with each preoperative value. [dagger, dagger] P < 0.01 compared with the isoflurane group.^ffP < 0.01 compared with the high-flow sevoflurane group.